Effects of Specific Movement Control Exercises on Lumbopelvic Motion and Trunk Muscle Activity During Walking
in Subjects With Lumbar Extension Rotation Pattern
The Graduate School
Yonsei University
Department of Physical Therapy
Sihyun Kim
Effects of Specific Movement Control Exercises on Lumbopelvic Motion and Trunk Muscle Activity During Walking
in Subjects With Lumbar Extension Rotation Pattern
Sihyun Kim
A Dissertation Submitted to the Department of Physical Therapy
and the Graduate School of Yonsei University in partial fulfillment of the
requirements for the degree ofDoctor of Philosophy
June 2014
This certifies that the doctoral dissertation ofSihyun Kim is approved.
The Graduate SchoolYonsei University
June 2014
Thesis Supervisor: Ohyun Kwon
Chunghwi Yi: Thesis Committee Member #1
Heonseock Cynn: Thesis Committee Member #2
Houngsik Choi: Thesis Committee Member #3
Jonghyuck Weon: Thesis Committee Member #4
Acknowledgements
In my life, the greatest opportunity was meeting my principal supervisor, Prof. Oh–
yun Kwon. In my early 20s, I was young and lacking in expertise in my area, but after
I met him, he provided a chance for me to grow. His creative thinking and
professional mind influenced me, so that I did not settle for the present and studied
and developed endlessly as a scholar. Without his help and guidance, it would have
been impossible for me to accomplish this research and develop my clinical skills. I
will not forget his assistance and affection. I take this chance to express my thanks to
him once again.
I also acknowledge Prof. Chung–hwi Yi for academic support and continued
attention. I thank Prof. Heon–seock Cynn for detailed comments and warm advice. I
learned so much from them and the quality of my dissertation was improved greatly
with their help. I want to express my deep appreciation to Prof. Jong–hyuck Weon
and Prof. Houng–sik Choi, who gave sincere advice and encouragement. I also
sincerely appreciate the help from Sang–hyun Cho, Joshua You, and Hye–seon Jeon
who gave continuous assistance and teaching during my doctoral courses.
I also thank my seniors, Jae–seop Oh, Mun–hwan Kim, Won–whee Lee, Sung–min
Ha, Su–jung Kim, Kyue–nam Park, and Sung–dae Choung, who spent a long time
with me during graduate school and were always willing to help. I am also grateful to
Young Kim, In–cheol Jeon, Ui–jae Hwang, Sun–hee Ahn, Sung–hoon Jung, and
Hyun–a Kim. I thoroughly enjoyed my doctoral student life with them. I am
immeasurably grateful for their support and help. I also thank all of my fellow
graduate students in the Department of Physical therapy and the subjects who
participated in my research.
Besides scholarly support, above all, I express deep appreciation to my family who
gave continuous affection and care. I could concentrate on my studies without any
difficulty with their support.
Although graduate school was difficult, it was also a challenge to constantly
develop more; I learned and gained many things. I sincerely express my deepest
gratitude once again to all the people who helped me to finish my dissertation.
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Table of Contents
List of Figures ···································································· ⅳ
List of Tables ····································································· ⅵ
Abstract ··········································································· ⅶ
Chapter
I. Introduction ····································································· 1
II. Comparison of Lumbopelvic Motion and Trunk Muscle Activity During
· Walking between Subjects With and Without Lumbar Extension Rotation
Pattern (Study 1)
Introduction ······································································· 3
Method ············································································· 7
1. Subjects ······································································ 7
2. Procedure ··································································· 10
3. Measurements ······························································ 11
3.1 Clinical Measures ····················································· 11
3.2 Surface Electromyography ··········································· 11
3.3 Kinematic Data ························································ 12
4. Data Analysis ······························································· 13
5. Statistical Analysis ························································ 15
Results ············································································ 16
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1. Spatio–temporal Parameters During Walking ·························· 16
2. Kinematics of Lumbopelvic Region ····································· 17
3. Electromyography Activities of Trunk Muscle ························ 20
Discussion ········································································ 25
III. Effects of a 6–week Program of Specific Movement Control Exercises
on Lumbopelvic Motion and Trunk Muscle Activity During Walking
in Subjects with Lumbar Extension Rotation Pattern (Study 2)
Introduction ······································································ 33
Method ············································································ 37
1. Design ······································································· 37
2. Subjects ····································································· 38
3. Measurements ······························································ 40
3.1 Clinical Measures ····················································· 40
3.2 Kinematics and Surface Electromyography ························ 40
4. Procedure ··································································· 42
5. Intervention ································································· 43
6. Data Analysis ······························································· 44
7. Statistical Analysis ························································ 46
Results ············································································ 47
1. Subject Characteristics ···················································· 47
2. Clinical Measures ·························································· 48
3. Spatio–temporal Parameters During Walking ·························· 50
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4. Kinematics of Lumbopelvic Region ····································· 51
5. Electromyography Activities of Trunk Muscle ························ 56
Discussion ········································································ 61
IV. Summary and Conclusion ·················································· 68
References ········································································ 70
Abstract in Korean ······························································· 79
Appendix 1. Protocol for the movement control exercise ···················· 83
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List of Figures
Figure 1. Comparison of the averaged pelvic and lumbar angles in the
sagittal and transverse planes between subjects with and without
the lumbar ExtRot pattern ··········································· 19
Figure 2. Comparison of the averaged ES and RA muscle activities
between subjects with and without the lumbar ExtRot pattern ·· 23
Figure 3. Comparison of the averaged EO and IO muscle activities
between subjects with and without the lumbar ExtRot pattern ·· 24
Figure 4. Flow chart for subject selection ····································· 39
Figure 5. Comparison of the averaged pelvic angle in the sagittal and
transverse planes during walking between pre– and post–
intervention ···························································· 54
Figure 6. Comparison of the averaged lumbar spine angle in the sagittal
and transverse planes during walking between pre– and post–
intervention ···························································· 55
Figure 7. Comparison of the averaged ES muscle activities during walking
between pre– and post–intervention ································ 57
Figure 8. Comparison of the averaged RA muscle activities during walking
between pre– and post–intervention ································ 58
Figure 9. Comparison of the averaged EO muscle activities during walking
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between pre– and post–intervention ································ 59
Figure 10. Comparison of the averaged IO muscle activities during walking
between pre– and post–intervention ································ 60
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List of Tables
Table 1. Subject’s characteristics ··············································· 9
Table 2. Stride characteristics ·················································· 16
Table 3. Pelvic and lumbar angles in sagittal and transverse planes in
subjects with and without the lumbar ExtRot pattern ············· 18
Table 4. Trunk muscle activities for subjects with and without the lumbar
ExtRot pattern ························································· 21
Table 5. Subject’s characteristics ·············································· 47
Table 6. Changes in pain intensity, disability, and fear avoidance beliefs
after 6–week intervention ··········································· 49
Table 7. Stride characteristics at pre–intervention ··························· 50
Table 8. Pelvic and lumbar angles in the sagittal and transverse planes ·· 52
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ABSTRACT
Effects of Specific Movement Control Exercises on
Lumbopelvic Motion and Trunk Muscle Activity
During Walking in Subjects With Lumbar
Extension Rotation Pattern
Sihyun Kim
Dept. of Physical Therapy
The Graduate School
Yonsei University
Walking is one of the most repetitive movements in daily activities and changes in
lumbopelvic motion and trunk muscle activities during walking are critical indicators
of spinal dysfunction. The purpose of Study 1 was to demonstrate the differences in
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lumbopelvic motion and trunk muscle activities during walking between subjects with
and without a lumbar extension rotation (ExtRot) pattern. In total, 26 subjects with a
lumbar ExtRot pattern and 18 subjects without lumbar ExtRot were recruited. Twenty
reflective markers were placed on the lower extremity and lumbar spine and a 3–D
motion analysis system was used to measure lumbopelvic kinematics. A surface
electromyography (EMG) system was used to measure the trunk muscle activities and
surface electrodes were attached on both rectus abdominis (RA), abdominal external
oblique (EO), abdominal internal oblique (IO), and erector spinae (ES) muscles. All
subjects walked 12 times at a self–selected (comfortable) walking speed on the
walkway. Kinematic data, at initial heel strike (HS), left toe–off (TO), left HS, and
right TO, and EMG data at first double support, left swing, second double support,
and right swing phase were used for the statistical analyses. To compare kinematic
and EMG data between subjects with and without the lumbar ExtRot pattern,
independent t–tests for parametric variables and Mann–Whitney U–tests for non–
parametric variables were used. Subjects with a lumbar ExtRot pattern showed
significantly increased pelvic and lumbar angles in the sagittal plane (p < 0.05);
however, there was no significant difference in the pelvic or lumbar angle in the
transverse plane between subjects with and without a lumbar ExtRot pattern (p >
0.05). In EMG activity, significantly increased activities in both ES muscles at all
events and decreased right IO muscle activity at the second double support phase
were seen in subjects with a lumbar ExtRot pattern versus subjects without (p < 0.05).
Both RA, EO, and IO muscle activities, except the right IO muscle activity at the
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second double support phase, were not significantly different between subjects with
and without the lumbar ExtRot pattern (p > 0.05).
The purpose of Study 2 was to demonstrate the effects of a 6–week specific
movement control exercise on pain behavior, lumbopelvic motion, and trunk muscle
activities during walking in subjects with a lumbar ExtRot pattern. In total, 39
subjects with lumbar a ExtRot pattern (experimental = 19; control = 20) participated
in this study. Subjects in the experimental group performed 6 weeks of movement
control exercises and the exercise level of difficulty was adjusted progressively.
Clinical outcome measures included pain intensity (visual analog scale), level of
disability (Oswestry disability index and Roland Morris disability questionnaire), and
fear and avoidance level (Fear–avoidance beliefs questionnaire) caused by low back
pain (LBP). To measure lumbopelvic kinematics and EMG activities in the trunk
muscles (RA, EO, IO, and ES) during walking, all subjects walked on an 8–m–long
straight walkway. Kinematic data at initial right HS, left TO, left HS, and right TO
and the EMG data at first double support, left swing, second double support and right
swing phase were used for the statistical analysis. The Wilcoxon signed–rank test for
non–parametric variables and the paired t–test for parametric variables were used to
compare baseline and follow–up treatment within a group. After the 6–week
intervention, pain intensity, level of disability, and fear and avoidance level caused by
LBP were decreased significantly in the experimental group. Additionally, there were
significantly decreased angles in the lumbar spine and pelvic region in the sagittal
plane at all events in the experimental group. However, there was no significant
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difference in the pelvic or lumbar angle in the transverse plane in either group. In the
EMG data, right ES muscle activity was decreased significantly during the first and
second double support phase and left ES muscle activity was also decreased
significantly during the second double support phase in the experimental group.
However, in the control group, there was no significant difference in lumbopelvic
motion or ES muscle activity. After the 6–week intervention, there was no significant
difference in abdominal muscle activity in either group.
Based on these two studies, it was demonstrated that subjects with a lumbar ExtRot
pattern had greater angle in the lumbar spine and pelvic region in the sagittal plane,
increased ES muscle activities at all events, and decreased right IO at the second
double support phase during walking, compared with subjects without a lumbar
ExtRot pattern. These changed patterns of lumbopelvic motion in the sagittal plane
and ES muscle activity and pain behavior in subjects with a lumbar ExtRot pattern
can be improved by specific movement control exercises over a 6–week course. Thus,
specific movement control exercises can be an effective treatment for subjects with a
lumbar ExtRot pattern to modify their excessive lumbopelvic motion in the sagittal
plane and excessive muscle activity of the ES in walking.
Key Words: Abdominal muscle, Electromyography, Erector spinae muscle, Low
back pain, Lumbar extension rotation pattern, Lumbopelvic motion,
Walking.
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Chapter Ⅰ
Introduction
Non–specific low back pain (LBP) is a common musculoskeletal problem (Crosbie
et al. 2013; Lamoth et al. 2006a; Seay, Van Emmerik, and Hamill 2011). Patients
with LBP have been reported to change their lumbopelvic kinematics and abdominal
muscle activities during walking (Arendt Nielsen et al. 1996; Crosbie et al. 2013;
Hanada, Johnson, and Hubley Kozey 2011; van der Hulst et al. 2010a, 2010b).
Altered lumbopelvic kinematics and abdominal muscle activities during walking are
important indicators for evaluation and treatment of LBP.
Recently, researchers and clinicians have suggested that sub–classification is
needed regarding treating patients with LBP, based on movement pattern–provoking
pain and/or symptoms in the lumbar spine during lumbar spine or lower extremity
movement (Hoffman et al. 2011; Hoffman et al. 2012; Kim et al. 2013; Sahrmann
2002; Scholtes, Gombatto, and Van Dillen 2009; Van Dillen et al. 2003). Non–
specific LBP is classified into extension, extension rotation (ExtRot), rotation, flexion
rotation, and flexion patterns. The lumbar ExtRot pattern is the most common form of
mechanical LBP (Sahrmann 2002). However, there is insufficient information related
to lumbopelvic motion and trunk muscle activity during walking in subjects with the
lumbar ExtRot pattern.
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For the management of patients with LBP, specific movement control exercises,
based on the sub–classification, have been emphasized by physical therapists (Kim et
al. 2013; Park et al. 2011; Sahrmann 2002; Scholtes, Gombatto, and Van Dillen 2009;
Van Dillen et al. 2003). Although several studies have reported the effects of specific
movement control exercises on LBP, there has been no report of the effects of
specific movement control exercises on lumbopelvic motion or trunk muscle
activities during walking in subjects with a lumbar ExtRot pattern (Hoffman et al.
2011; Maluf, Sahrmann, and Van Dillen 2000; Scholtes et al. 2010).
Thus, this study was designed to compare lumbopelvic motion and trunk muscle
activities during walking in subjects with and without the lumbar ExtRot pattern and
to examine the effects of a specific movement control exercise on lumbopelvic
motion, trunk muscle activity, and pain behavior during walking in subjects with the
lumbar ExtRot pattern.
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Chapter II
Comparison of Lumbopelvic Motion and Trunk Muscle
Activity During Walking between Subjects With and
Without Lumbar Extension Rotation Pattern
(Study 1)
Introduction
Low back pain (LBP) is a major musculoskeletal problem and the relationship
between LBP and motor performance has been studied under dynamic movement
(Crosbie et al. 2013; Lamoth et al. 2006a, 200b; Seay, Van Emmerik, and Hamill
2011). Some investigators have reported that impaired control of lumbopelvic motion
could cause excessive or early lumbopelvic motion during lower extremity movement
(Kim et al. 2013; Park et al. 2011; Scholtes, Gombatto, and Van Dillen 2009;
Scholtes et al. 2010). Specifically, in functional activities, continuous and repetitive
movement of the lumbar spine is one of the important factors in cumulative stress in
soft tissue, which may lead to macro–trauma and pain in the low back. According to
the movement impairment system model, mechanical LBP can be classified into
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lumbar extension, extension rotation (ExtRot), rotation, flexion rotation, and flexion
patterns, based on movement direction of the lumbar spine that induces pain and/or
symptoms (Maluf, Sahrmann, and Van Dillen 2000; Sahrmann 2002; Trudelle-
Jackson, Sarvaiya-Shah, and Wang 2008). These sub–classifications can be diagnosed
through trunk and lower extremity movement tests and patients with lumbar ExtRot
pattern represent the highest proportion of mechanical LBP cases (Hoffman et al.
2011, 2012; Kim et al. 2013; Sahrmann 2002; Scholtes, Gombatto, and Van Dillen
2009; Van Dillen et al. 2003).
Walking is one of most important tasks in daily activities and optimal
neuromuscular control of the lumbopelvic motion is required to maintain trunk
posture in walking (Saunders et al. 2005). Patients with LBP show slower gait
velocity than pain–free individuals (Hanada, Johnson, and Hubley Kozey 2011).
Additionally, a less variable and more tightly coordinated movement between the
pelvic and lumbar spine was demonstrated in individuals with LBP versus healthy
subjects. An abnormal coupling motion may be an indicator of spine dysfunction
(Crosbie et al. 2013; Lamoth et al. 2006a). Thus, it is believed that altered lumbar
motion may be closely related to LBP during walking.
The trunk muscles have been reported to play an important role in the control of
lumbopelvic motion during physical activities (Panjabi 1992; Saunders et al. 2005)
and differences in activation patterns of trunk muscles were demonstrated in patients
with LBP compared with asymptomatic controls (Saunders et al. 2005; van der Hulst
et al. 2010a, 2010b). Erector spinae (ES) muscle activity tends to decrease during the
- 5 -
ipsilateral and contralateral swing phases of gait, and to increase during double stance
in healthy subjects (Lamoth 2006b; van der Hulst et al. 2010b). However, higher ES
activity was demonstrated in patients with LBP during all gait phases (van der Hulst
et al. 2010a, 2010b). During gait, the rectus abdominis (RA), abdominal external
oblique (EO), and abdominal internal oblique (IO) muscle were activated
continuously during all stride phases, and increased activity of the superficial
abdominal muscles was demonstrated in subjects with LBP compared with controls as
a guarding mechanism for pain (van der Hulst et al. 2010a, 2010b; White, and
McNair 2002). Hanada, Johnson, and Hubley Kozey (2011) reported both RA and
right IO muscle activity in the left loading response phase were activated significantly
more in the control group than in the LBP group. However, these studies were
conducted using different electromyography (EMG) normalization methods and
performed without sub–classification of the mechanical LBP.
Although changes in lumbopelvic kinematics and trunk muscle activities during
walking in the LBP have been reported, the reports have been inconsistent and it is
difficult to demonstrate altered movement and muscle activities during walking
according to the sub–type of LBP. In particular, subjects with the lumbar ExtRot
pattern showed excessive lumbar extension and rotation in standing alignment and
movement of the lumbar spine, towards extension and rotation, during knee flexion,
hip rotation in the prone position, and when returning from forward bending
(Hoffman et al. 2011; Park et al. 2011; Sahrmann 2002). Although these studies have
demonstrated movement characteristics in subjects with lumbar ExtRot pattern using
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lower limb or trunk movement tests (Hoffman et al. 2011; Kim et al. 2013; Park et al.
2011; Sahrmann 2002; Scholtes, Gombatto, and Van Dillen 2009), there has been no
reported study of the movement changes in the lumbopelvic region in the lumbar
ExtRot pattern during walking. Thus, in this study, it was expected that subjects with
a lumbar ExtRot pattern would show excessive lumbar extension and rotation
movement during walking, compared with healthy subjects. The purpose of this study was to compare the kinematics of the lumbar spine and
pelvic region in the sagittal and transverse planes and trunk muscle activities (RA, EO,
IO, and ES) during walking between subjects with and without a lumbar ExtRot
pattern. It was hypothesized that subjects with a lumbar ExtRot pattern would show
greater lumbopelvic motion in the sagittal and transverse planes, reflected by
decreased activities of the superficial abdominal muscles and increased activity of the
ES muscle.
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Method
1. Subjects
First, 63 subjects with LBP were screened by a physical therapist with 4 years
clinical experience in evaluating and managing LBP, based on a movement
impairment classification. In total, 26 subjects with a lumbar ExtRot pattern
participated (Table 1). In all subjects, the duration of LBP was over 7 weeks. An
examination based on the movement impairment classification by Sahrmann (2002)
was used to identify the sub–group with a lumbar ExtRot pattern among the
mechanical LBP cases. A two–step procedure consisted of primary and secondary
tests. The primary test was a symptom–provocation test designed to assess movement
of the lumbar spine associated with the symptoms and/or pain, while the secondary
test was a confirmatory test designed to decrease or inhibit the symptoms by
modifying the subject’s movement patterns in the lumbar spine. Test items consisted
of standing (alignment, return from forward bending, lumbar extension, and side
bending), sitting (alignment and lumbar extension), supine (active hip abduction and
external rotation), prone (alignment, active hip internal/external rotation, hip
extension, and knee flexion), and quadruped position (alignment, active arm lift,
rocking backward, and rocking forward). The test was positive, if 1) lumbar spine
alignment tended to be extended and rotated relative to neutral and 2) the lumbar
- 8 -
spine moved towards the direction of extension and rotation with movements in the
spine or extremities. If the subjects with LBP reported an increase in symptoms or
pain with lumbar extension and rotation during the primary test, the secondary test
was performed. All subjects with a lumbar ExtRot pattern had dominant symptoms on
the right side.
The 18 matched subjects with no lumbar ExtRot pattern had no history of LBP
during the last 6 months (Table 1). Subjects were excluded if they reported having a
1) neurological signs or a diagnosis by a physician, 2) fracture, injury, or surgery on
the lower back, hip, knee, and ankle, or 3) pain or symptoms that affected movement
of the hip, knee, or ankle joint. All participants signed an informed consent statement
and were supplied with information sheets prior to participation. The study was
approved by the Yonsei University Wonju institutional review board.
- 9 -
Table 1. Subjects’ characteristics
Parameter With lumbar
ExtRot pattern
Without lumbar
ExtRot pattern Statistic p
Gender (male/female) M=11/F=15 M=10/F=8 N/A N/A
Age (years) 23.15 ± 1.97a 22.78 ± 1.96 0.624 0.536
Body mass (㎏) 62.31 ± 11.56 60.50 ± 7.66 0.624 0.536
Height (㎝) 164.28 ± 22.41 169.89 ± 7.32 -1.021 0.313
Pain duration (months) 21.69 ± 16.47 N/A N/A N/A
VASb (㎜) 31.76 ± 16.49 N/A N/A N/A
Modified ODIc (%) 11.96 ± 6.55 N/A N/A N/A aMeans ± standard deviation. bVAS: visual analog scale. cODI: Oswestry disability index. N/A = not applicable.
- 10 -
2. Procedure
Subjects were allowed to walk on the walkway until they were accustomed to the
walking conditions in the experimental room. Subjects were asked to walk on an 8–
m–long straight walkway at their preferred speed using more than 12 time–strides for
data collection. A rest of 30 s was provided between trials.
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3. Measurements
3.1 Clinical Measures
To measure the severity and perception of LBP, a visual analog scale (VAS) was
used (Marshall, and Murphy 2010). Subjects were required to mark their subjective
pain level on a 100–㎜ horizontal line with 10–㎜ marks. VAS scores represented
pain values from “0” (no pain) to “100” (worst pain imaginable).
The modified Oswestry disability index (ODI) was used to measure disability
related to LBP (Kim et al. 2005). The modified ODI questionnaire was scored on a
scale of 0–5, and consisted of 10 items with six answers per item. The total score for
each subject was showed as a relative value (total possible score / total score × 100).
The index was scored from “0” (no disability) to “100” (total disability).
3.2 Surface Electromyography
EMG data were collected using a Noraxon system (Noraxon, Scottsdale, Arizona,
USA) with 1000 ㎐ sampling rate. For all EMG data, first–order high–pass filters
were set to 10 ㎐ and low–pass filters were set to 1500 ㎐. All channels had tenth–
order low–pass smoothing filters too. Surface EMG electrodes with a 2–㎝ inter–
electrode distance were attached at the muscle belly of both abdominal muscles (RA,
EO and IO) and the ES after the removal of hair and cleaning the patient’s skin with
alcohol.
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3.3 Kinematic Data
Lumbar and pelvic motion during gait were recorded using a motion–analysis
system with six cameras (Vicon MX system, Oxford Metrics, Oxford, UK) with 100
㎐ sampling rate. All marker coordinates were smoothed with a Woltring filter (Lee
et al. 2013). Twenty reflective markers (14–㎜ circles) were placed including lower
lumbar markers (on the spinous processes of T12 and L1, and 3 ㎝ on the left and
right sides of the spinous process of L1), and lower extremity markers (bilaterally on
the skin overlying the anterior superior iliac spine, posterior superior iliac spine,
lateral aspect of the thigh, lateral epicondyle of the femur, lateral surface of the shank,
lateral malleolus, second metatarsal head, and the posterior midpoint of the calcaneus).
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4. Data Analysis
EMG and kinematic data were collected using Nexus 1.4 software and imported
into the Polygon software for data analysis. Spatio–temporal parameters such as
walking speed, cadence, step length, and step time were computed from the 3D
kinematics. Events of the gait cycle (heel strike, HS, and toe–off, TO) were
determined by heel and second metatarsal head markers according to Pijnappels,
Bobbert, and van-DieÃn (2001). HS was defined by the minimum in the vertical
velocity of the second metatarsal head marker and TO was defined by the maximum
in the vertical velocity of the heel marker. A one–stride cycle was defined from the
initial HS to the next HS of the same leg and all data were analyzed based on the right
leg. For each kinematic and EMG recording, each of these time series were time–
normalized and resampled to 0–100 % of the stride cycle. Twelve time–normalized
kinematic and EMG data sets were used for data analysis of the within–participant
ensemble average.
The raw EMG data were processed using a root–mean–square algorithm. The
muscle activity recorded during the walk was then expressed as a percentage of the
sub–maximal voluntary isometric contraction (sub–MVIC). The sub–MVIC for the
abdominal muscle was performed to lift in hook–lying both legs 1 ㎝ from the table
(Dankaerts et al. 2004). For ES sub–MVIC, subjects raised both leg with knee flexion
at 90° from the table in a prone position (Dankaerts et al. 2004). Three repetitions of
- 14 -
5–s–long contractions for each task were conducted with a 30–s rest between them.
Each mean EMG activities of the RA, EO, IO, and ES were used for statistical
analysis at first double support, left swing, second double support, and right swing.
The first double support was defined from right HS to left TO, followed by left swing
until left HS. The second double support was defined from left HS to right TO,
followed by right swing until right HS.
The three–dimensional angle of the lumbar spine and the pelvic region were
analyzed using a global xyz–coordinate system, with the x–axis corresponding to the
line of progression, the y–axis pointing sideways, and the z–axis, vertically upwards.
The segment axes were aligned with the global system of reference. The pelvic angle
was obtained relative to the global coordinate system and the angle of the lumbar
spine was calculated using the relative orientation of the pelvic segment. Data were
collected in the sagittal and transverse plane. Each angle of the lumbar and pelvic
movements was used for statistical analysis at right HS, left TO, left HS, and right TO.
- 15 -
5. Statistical Analysis
SPSS 21.0 for Windows (SPSS, Inc., Chicago, IL, USA) was used for all statistical
analyses. The Shapiro–Wilk test was used to assess the normality of the distribution
of the variables (spatiotemoral parameters, kinematic data of the lumbar spine and
pelvis, and EMG data of the trunk muscles). If variables were confirmed to be
normally distributed, parametric statistics (independent t–test) were used while if not,
non–parametric statistics (Mann–Whitney U–test) were used to compare variables
between subjects with and without lumbar ExtRot pattern. The level of statistical
significance was set at p < 0.05.
- 16 -
Results
1. Spatio–temporal Parameters During Walking
There was no significant difference between the groups in walking speed, cadence,
stride time, or stride length (p > 0.05; Table 2)
Table 2. Stride characteristics
Stride characteristics With lumbar ExtRot
pattern (n = 26)
Without lumbar ExtRot
pattern (n = 18) p
Walking speed (㎧) 1.14 ± 0.13a 1.14 ± 0.18 0.926
Cadence (steps/min) 117.83 ± 14.68 112.79 ± 10.08 0.214
Stride time (s) 1.03 ± 0.09 1.07 ± 0.09 0.128
Stride length (m) 1.17 ± 0.20 1.21 ± 0.11 0.474 aMean ± standard deviation.
- 17 -
2. Kinematics of Lumbopelvic Region
There were significant differences in pelvic anterior tilting and the lumbar
extension angle at all events between subjects with and without lumbar ExtRot
pattern (p < 0.05; Table 3). Subjects with a lumbar ExtRot pattern showed greater
pelvic anterior tilting and lumbar extension angles at all events than subjects without
a lumbar ExtRot pattern (Figure 1). There was no significant difference in pelvic or
lumbar rotation angle in any event between subjects with and without the lumbar
ExtRot pattern (p > 0.05; Table 3).
- 18 -
Table 3. Pelvic and lumbar angles in the sagittal and transverse planes in subjects
with and without the lumbar ExtRot pattern
aHS: heel strike. bTO: Toe–off. cMean ± standard deviation (°). ‘+’ indicates counter–clockwise rotation and ‘−’ indicates clockwise rotation in transverse plane. *p < 0.05.
Motion Event With lumbar
ExtRot pattern
Without lumbar
ExtRot pattern p
Pelvic
anterior tilting
Right HSa 10.82 ± 3.53c 8.17 ± 3.97 0.025*
Left TOb 10.59 ± 3.59 7.76 ± 3.88 0.017*
Left HS 11.17 ± 3.68 8.64 ± 4.18 0.040*
Right TO 11.02 ± 3.75 8.38 ± 4.19 0.034*
Pelvic rotation Right HS 4.19 ± 2.83 3.08 ± 3.11 0.262
Left TO 4.10 ± 2.48 2.90 ± 2.93 0.149
Left HS -4.56 ± 3.53 -3.72 ± 3.39 0.435
Right TO -4.15 ± 3.49 -3.25 ± 3.41 0.364
Lumbar
extension
Right HS 11.46 ± 6.21 5.42 ± 5.78 0.002*
Left TO 12.40 ± 6.44 5.96 ± 6.04 0.002*
Left HS 11.14 ± 6.00 5.25 ± 5.90 0.002*
Right TO 11.42 ± 6.48 6.04 ± 5.90 0.008*
Lumbar rotation Right HS -0.18 ± 3.54 0.69 ± 3.36 0.417
Left TO -0.16 ± 3.56 0.87 ± 3.42 0.348
Left HS -4.03 ± 4.19 -3.59 ± 2.90 0.535
Right TO -4.54 ± 4.77 -3.92 ± 3.11 0.628
- 19 -
0
2
4
6
8
10
12 * * * *
Rt. HS Lt. TO Lt. HS Rt. TO
Pelv
ic a
nter
ior t
iltin
g (º
)
0
2
4
6
8
10
12
14
16
* ** *
Rt. HS Lt. TO Lt. HS Rt. TO
Lum
bar e
xten
sion
(º)
Figure 1. Comparison of the averaged pelvic and lumbar angles in the sagittal and
transverse planes between subjects with and without the lumbar ExtRot
pattern. ‘+’ indicates counterclockwise rotation and ‘−’ indicates clockwise
rotation in the transverse plane (HS, heel strike; TO, toe–off). *p < 0.05
significantly different between the groups.
-8
-6
-4
-2
0
2
4With lumbar ExtRot patternWithout lumbar ExtRot pattern
Rt. HS Lt. TO Lt. HS Rt. TO
Lum
bar r
otat
ion
(º)
-5
-4
-3
-2
-1
0
1
2
3
4
Rt. HS Lt. TO Lt. HS Rt. TO
Pelv
ic ro
tatio
n (º
)
- 20 -
3. Electromyography Activities of Trunk Muscle
There were significant differences in both ES muscle activities in all events and in
right IO muscle activities at the second double support phase between subjects with
and without a lumbar ExtRot pattern (p < 0.05; Table 4). Both ES muscle activities
increased significantly in subjects with lumbar ExtRot pattern compared with subjects
without the lumbar ExtRot pattern in all events (Figure 2). Right IO muscle activity
decreased significantly in subjects with a lumbar ExtRot pattern than subjects without
the lumbar ExtRot pattern at the second double support phase (Figure 3). There was
no significant difference in either RA, EO, or IO muscle activities in any event except
for right IO muscle activities in the second double support phase between subjects
with and without a lumbar ExtRot pattern (p > 0.05).
- 21 -
Table 4. Trunk muscle activities for subjects with and without the lumbar ExtRot
pattern
Muscle Phase With lumbar
ExtRot pattern
Without lumbar
ExtRot pattern p
ESa
Rt First double support 26.26 ± 11.27e 17.91 ± 8.40 0.009*
Left swing 22.76 ± 8.96 16.25 ± 7.78 0.013*
Second double support 24.15 ± 9.22 17.15 ± 6.54 0.003*
Right swing 23.96 ± 8.15 18.54 ± 6.47 0.026*
Lt First double support 23.28 ± 9.55 16.65 ± 8.05 0.009*
Left swing 24.27 ± 14.70 18.13 ± 10.58 0.011*
Second double support 22.84 ± 10.33 16.45 ± 9.78 0.019*
Right swing 22.42 ± 14.53 14.30 ± 7.29 0.005*
RAb
Rt First double support 27.59 ± 16.79 26.70 ± 27.79 0.328
Left swing 38.04 ± 47. 65 29.01 ± 20.26 0.352
Second double support 29.01 ± 20.26 31.04 ± 37.07 0.390
Right swing 38.80 ± 45.12 33.96 ± 42.18 0.105
Lt First double support 29.52 ± 16.11 28.55 ± 24.92 0.352
Left swing 36.60 ± 24.93 36.15 ± 39.33 0.417
Second double support 28.89 ± 14.45 27.80 ± 24.90 0.223
Right swing 38.62 ± 31.03 36.74 ± 49.54 0.252 aES: erector spine muscle. bRA: rectus abdominis muscle. cEO: abdominal external oblique muscle. dIO: abdominal internal oblique muscle. eMean ± standard deviation (% sub–MVIC). *p < 0.05.
- 22 -
Table 4. (Continued)
Muscle Phase With lumbar
ExtRot pattern
Without lumbar
ExtRot pattern p
EOc
Rt First double support 45.51 ± 30.68 39.45 ± 27.94 0.223
Left swing 47.34 ± 39.93 37.84 ± 28.08 0.252
Second double support 40.37 ± 20.78 37.03 ± 23.60 0.364
Right swing 52.24 ± 45.89 42.83 ± 32.41 0.283
Lt First double support 45.60 ± 25.99 57.20 ± 56.90 0.867
Left swing 57.11 ± 50.32 54.73 ± 37.73 0.793
Second double support 50.28 ± 24.07 52.95 ± 37.58 0.650
Right swing 52.25 ± 45.48 46.60 ± 32.34 0.504
IOd
Rt First double support 73.07 ± 49.52 101.61 ± 96.55 0.445
Left swing 67.20 ± 40.80 75.66 ± 44.63 0.445
Second double support 64.99 ± 33.48 97.00 ± 53.31 0.032*
Right swing 68.64 ± 41.16 84.55 ± 53.49 0.262
Lt First double support 73.46 ± 44.33 93.93 ± 69.99 0.535
Left swing 62.06 ± 33.20 71.77 ± 48.12 0.811
Second double support 72.28 ± 39.90 81.79 ± 68.39 0.905
Right swing 57.02 ± 31.02 67.42 ± 5073 0.685 aES: erector spine muscle. bRA: rectus abdominis muscle. cEO: abdominal external oblique muscle. dIO: abdominal internal oblique muscle. eMean ± standard deviation (% sub–MVIC). *p < 0.05.
- 23 -
0
10
20
30
40
Rt ES
*** *
Firstdouble support
Lt. swing Rt. swingSeconddouble support
EM
G a
ctiv
ity (
% s
ub M
VIC
)
0
10
20
30
40
50
60
Rt RA
Firstdouble support
Lt. swing Rt. swingSeconddouble support
EM
G a
ctiv
ity
(%
su
b M
VIC
)
Figure 2. Comparison of the averaged ES and RA muscle activities between subjects
with and without the lumbar ExtRot pattern (MVIC: maximal voluntary
isometric contraction, ES: erector spine muscle, RA: rectus abdominis
muscle). *p < 0.05significantly different between the groups.
0
10
20
30
40
50
60With lumbar ExtRot pattern
Without lumbar ExtRot pattern
Lt RA
Firstdouble support
Lt. swing Rt. swingSeconddouble support
0
10
20
30
40
Lt ES
* * *
Firstdouble support
Lt. swing Rt. swingSeconddouble support
*
- 24 -
0
10
20
30
40
50
60
70
80
Rt EO
Firstdouble support
Lt. swing Rt. swingSeconddouble support
EM
G a
ctiv
ity (
% s
ub M
VIC
)
0
10
20
30
40
50
60
70
80
Lt EO
Firstdouble support
Lt. swing Rt. swingSeconddouble support
0
20
40
60
80
100
120
Rt IO
Firstdouble support
Lt. swing Rt. swingSeconddouble support
*
EM
G a
ctiv
ity
(%
su
b M
VIC
)
Figure 3. Comparison of the averaged EO and IO muscle activities between subjects
with and without the lumbar ExtRot pattern (MVIC: maximal voluntary
isometric contraction, EO: abdominal external oblique muscle, IO:
abdominal internal oblique muscle). *p < 0.05 significantly different
between the groups.
0
20
40
60
80
100
120 With lumbar ExtRot pattern
Without lumbar ExtRot pattern
Lt IO
Firstdouble support
Lt. swing Rt. swingSeconddouble support
- 25 -
Discussion
LBP is common musculoskeletal problem and has been investigated continuously
the diagnosis and management of LBP according to specific sub–groups. Although
many previous studies have examined the relationship between lumbopelvic motion
and trunk muscle activity between patients with LBP and a healthy control group in
walking (Arendt Nielsen et al. 1996; Crosbie et al. 2013; Hanada, Johnson, and
Hubley Kozey 2011; van der Hulst et al. 2010a, 2010b), this is the first reported study
to determine whether subjects with a lumbar ExtRot pattern demonstrated different
lumbopelvic motion and trunk muscle activities in walking. Novel findings from this
study include that the pelvic and lumbar angles in the sagittal plane were greater in
subjects with the ExtRot pattern than in subjects without a lumbar ExtRot pattern in
walking. Increased muscle activity was also observed in both ES at all events and
decreased right IO muscle activity was seen at the second double support phase in
subjects with the ExtRot pattern compared with subjects without a lumbar ExtRot
pattern. However, in contrast to the initial hypothesis, there was no difference
between the two groups in RA, EO, and IO muscle activities, with the exception of
right IO muscle activity at the second double support phase throughout walking.
Walking speed influences trunk muscle activities and movement amplitudes in the
lumbopelvic region (Crosbie et al. 2013; Lamoth et al. 2006a; Seay, Van Emmerik,
and Hamill 2011). Seay, Van Emmerik, and Hamill (2011) reported that pelvis and
- 26 -
trunk range of motion during walking increased as speed increased, in LBP and pain–
free subjects, and Lamoth et al. (2006a) demonstrated that subjects with LBP have a
decreased ability to adapt trunk–pelvis coordination and ES muscle activities in
response to gait velocity. Although previous researchers have found differences in
spatiotemporal parameters between patients with LBP and pain–free control subjects,
with LBP patients tending to have a slower speed of the walking and a shorter step
length (Crosbie et al. 2013; Lamoth et al. 2006b), this study showed no significant
difference in spatiotemporal parameters in walking between subjects with and without
a lumbar ExtRot pattern. Thus, the similarity in the spatiotemporal parameters
between subjects with and without a lumbar ExtRot pattern is not likely a major
contributor affecting lumbopelvic kinematics or muscle activities of the trunk muscles
in this study.
Lumbopelvic motion is important because a greater movement angle may
contribute to evoking pain in the lumbopelvic region (Scholtes, Gombatto, and Van
Dillen 2009). Repetitive and/or sustained movement of the lumbar spine towards a
specific direction contributes to increase stress in the lumbopelvic region and can
induces microtrauma, resulting in LBP (Sahrmann 2002). Individuals with a lumbar
ExtRot pattern are characterized by a tendency to move and align the lumbar region
in rotation and extension in movement tests and functional activities (Maluf,
Sahrmann, and Van Dillen 2000; Sahrmann 2002; Trudelle-Jackson, Sarvaiya-Shah,
and Wang 2008). Previous studies have demonstrated differences in lumbopelvic
- 27 -
motion between subjects with LBP and healthy controls during movement tests, such
as hip extension, hip lateral rotation, and knee flexion in a prone position (Park et al.
2011; Scholtes, Gombatto, and Van Dillen 2009). Researchers have suggested that
increased and greater movement amplitude of the lumbar spine during these
movement tests is one of the reasons for LBP, which influences daily activities such
as gait and running. The results of the present study are consistent with previous
studies on LBP: increased anterior pelvic tilting and lumbar extension angle in all
events in subjects with the lumbar ExtRot pattern compared with subjects without a
lumbar ExtRot pattern. Thus, the altered lumbopelvic kinematics in subjects with
lumbar ExtRot pattern may cause excessive stress with extension into the lumbar
spine, resulting in induction of LBP in walking.
In this study, there was no significant difference in pelvic or lumbar angle in the
transverse plane during walking (p > 0.05). A reason for this result may be that the
subjects participating in this study had relatively mild pain (VAS = 31.76 ± 16.49 ㎜)
and were university students in their early 20s. Although the subjects satisfied the
criteria for the lumbar ExtRot pattern, it is possible that pain severity was not
sufficient to change their movement patterns in the lumbopelvic region during
walking. Although there was no significant difference in the pelvic or lumbar angle in
the transverse plane between subjects with and without a lumbar ExtRot pattern, the
overall pelvic rotation angle was greater at all events in subjects with lumbar ExtRot
pattern compared to subjects without lumbar ExtRot pattern. Thus, further studies are
- 28 -
needed to confirm the changes in lumbopelvic motion in the transverse plane in
subjects with lumbar ExtRot pattern while having more severe LBP.
Several mechanisms could explain the greater lumbopelvic angle in sagittal plane
in subjects with a lumbar ExtRot pattern. First, biomechanical limitations may alter
the lumbopelvic motion. Previous studies explained that greater amplitude in the
lumbopelvic region with knee flexion in people with LBP is caused by a short or stiff
rectus femoris muscle and tensor fascia latae/iliotibial band because this muscle
passes across two joints (hip and knee joint) (Kim et al. 2013; Park et al. 2011;
Scholtes, Gombatto, and Van Dillen 2009). After initial HS, the ipsilateral leg goes
into a stance phase with ipsilateral knee flexion and hip extension initiation. Thus, the
greater pelvic motion in the sagittal plane at TO in this study may be attributable to a
lack of flexibility or the length of the rectus femoris and tensor fascial latae/iliotibial
band. Also, individuals with a lumbar ExtRot pattern have hyperlordosis
characteristics in standing, which can be caused by a short and stiff iliopsoas muscle
(Harris-Hayes, Van Dillen, and Sahrmann 2005; Sahrmann 2002). Thus, changes in
biomechanical aspects could influence lumbopelvic kinematics during walking. A
second reason may involve a learned movement strategy. People with a lumbar
ExtRot pattern present with easier movement into anterior pelvic tilting and rotation.
Relatively greater flexibility of the abdominal muscle, compared with the rectus
femoris, could induce greater pelvic anterior tiling. Kim et al. (2013) and Park et al.
(2011) examined that greater lumbopelvic motion during knee flexion in standing and
- 29 -
prone positions in subjects with a lumbar ExtRot pattern compared with subjects with
no lumbar ExtRot pattern. This result was consistent with previous findings of greater
lumbar extension and anterior tilting during walking in subjects with a lumbar ExtRot
pattern. Third, the altered EMG activity of the trunk muscle is a factor in the greater
lumbopelvic angle. The primary action of the ES is to control the lumbar spine
motion in the sagittal plane (Lamoth et al. 2006b). Figure 2 shows, in both ES
muscles, greater muscle activation in subjects with a lumbar ExtRot pattern in all
events. Excessive muscle activation of the ES could contribute to an excessive lumbar
lordotic curve in walking. Also, this study did not show significant differences in RA,
EO, and IO muscle activities, except in the right IO muscle at the second double
support phase during walking between the groups. However, right IO muscle activity
at the second double support phase was decreased significantly and both IO muscle
activities showed a decreasing tendency across all events in subjects with a lumbar
ExtRot pattern compared with subjects without a lumbar ExtRot pattern (Figure 3).
Abdominal muscles, especially the IO muscles, act as stabilizers of the lumbar spine
(O'Sullivan, Twomey, and Allison 1998; van Dieën, Cholewicki, and Radebold 2003).
Insufficient recruitment of the IO muscle may contribute to excessive lumbopelvic
motion in subjects with a lumbar ExtRot pattern. Thus, it is possible that decreased IO
muscle activity makes it difficult to maintain spinal stability.
The ES muscle showed peak activation in the double–leg stance, to control trunk
movement, in contrast to the lack of EMG activity in a single leg stance (van der Huls
- 30 -
et al. 2010a, 2010b). Increased muscle activity of the ES during a double–leg stance
could facilitate efficient control of anterior or lateral deviation of the trunk in the
sagittal plane. However, overall higher ES muscle EMG activities have been reported
during walking in people with LBP than in healthy controls (van der Huls et al. 2010a,
2010b). The previous results are consistent with this study in that both ES muscle
activity was greater at all phases in subjects with the lumbar ExtRot pattern (p < 0.05).
This result could be explained by the pain–spasm–pain model (van Dieën, Cholewicki,
and Radebold 2003; Vogt, Pfeifer, and Banzer 2003). Continuous activity of the ES to
maintain posture causes localized muscle fatigue, and this can exacerbate and
continue the LBP. In this study, subjects with a lumbar ExtRot pattern showed
increased muscle activities in the ES compared with those in subjects without a
lumbar ExtRot pattern; this change may be a factor in LBP.
Previous studies have reported the patterns of abdominal muscle activation during
gait; however, inconsistent results have been reported (Hanada, Johnson, and Hubley
Kozey 2011; van der Hulst et al. 2010a; White, and McNair 2002). Several studies
have reported that the RA, as an anterior global muscle, is activated constantly
without a connection to the dynamic movement of the gait cycle (Hanada, Johnson,
and Hubley Kozey 2011; Saunders et al. 2005; van der Hulst et al. 2010a), while
other studies have reported that RA contributes to lumbopelvic movement in the
sagittal plane in healthy subjects (White, and McNair 2002). Additionally, the EO
muscle, anatomically, would seem to be plausibly associated with lumbopelvic
- 31 -
motion in the transverse plane during stance, while White, and McNair (2002)
reported that most subjects used the EO muscle at a level of < 5% MVC throughout
the stride. A similar pattern is also seen in the IO muscle, with relatively constant
low–level activity during slow gait in most subjects (Anders et al. 2007; White, and
McNair 2002). Variability in the abdominal muscle activation patterns among
individuals may have led to inconsistent results during walking. Thus, this study
showed no significant differences of the RA, EO, or IO, except in the right IO muscle
at the second double support phase, during walking between subjects with and
without a lumbar ExtRot pattern.
Several previous studies compared abdominal muscle activities between LBP and
control groups and reported increased muscle activity of the RA, but not the OE, in
subjects with LBP compared with those without during walking (Hanada, Johnson,
and Hubley Kozey 2011; van der Hulst et al. 2010a). However, in the present study,
no significant difference in abdominal muscle activity was found between the two
groups during walking. The inconsistency between the results of prior studies and our
findings may be explained by methodology: specifically, the normalization of the
EMG data. Generally, although MVIC is often used to normalize EMG activity, this
method is unreliable for patients because patients with LBP are usually unwilling or
unable to perform maximum contractions of the abdominal muscle, not least because
of fear of pain. Thus, methodological differences in normalizing the EMG activities
of the abdominal muscle may be the reason for the differing results.
- 32 -
Although this study demonstrated differences in lumbopelvic motion and trunk
muscle activities between subjects with and without a lumbar ExtRot pattern, it had
several limitations. The first limitation was the difficulty in determining whether
these changes cause LBP or occur due to pain, because this was a cross–sectional
study. Repetitive and/or continuous movement of the lumbar spine may be a risk
factor for LBP; however, in this study, it is difficult to demonstrate a cause and effect
relationship between LBP and excessive pelvic anterior tilting and lumbar extension
angle and increased ES muscle activities. Further study is necessary to determine the
effects of the decreased pelvic and lumbar angle in the sagittal plane that could
influence changes in ES muscle activities during walking and pain intensity in
subjects with a lumbar ExtRot pattern. Second, these results may not be
generalizable; all subjects in this study were university students. Thus, further
research is required to examine lumbopelvic motion in walking in people with LBP
over a variety of ages. Third, because the subjects participating in this study had
symptoms and/or pain related to their lumbar ExtRot pattern, it is unknown whether
the movement patterns of the lumbopelvic region and EMG activity of the trunk
muscle would be generalizable to other sub–groups of LBP, such as subjects with
lumbar flexion, flexion and rotation, rotation, and extension patterns. Further studies
are necessary to confirm the differences in the lumbopelvic motion and trunk muscle
activities in diverse sub–groups of LBP.
- 33 -
Chapter III
Effects of a 6–week Program of Specific Movement
Control Exercises on Lumbopelvic Motion and Trunk
Muscle Activity During Walking in Subjects with
Lumbar Extension Rotation Pattern
(Study 2)
Introduction
LBP is one of the major musculoskeletal disorders, and its treatment and
management in modern society incur enormous costs (Magalhaes et al. 2013;
Maniadakis, and Gray 2000; O'Sullivan 2005; Rasmussen-Barr et al. 2009). One
reason for LBP is motor control impairment in the lumbar spine (Vogt et al. 2001).
Excessive and repetitive movement in the lumbar spine may cause stress and
microtrauma in facet joints, resulting in pain of the low back region (Sahrmann 2002;
Scholtes, Gombatto, and Van Dillen 2009). Thus, it is important to focus on
controlling lumbopelvic motion during rehabilitation from chronic LBP.
Spinal coordination during walking has been considered to be important in
- 34 -
preventing LBP (Crosbie et al. 2013). Patients with chronic and recurrent LBP have
shown altered movement patterns and poor adjustment abilities in the lumbar spine
(Lamoth et al. 2006a, 2006b; Seay, Van Emmerik, and Hamill 2011). Several studies
have assessed coordination of the lumbar spine and pelvis between subjects with and
without LBP during walking (Crosbie et al. 2013; Lamoth et al. 2006a; Seay, Van
Emmerik, and Hamill 2011). Lamoth et al. (2006a) showed decreased coordination
between the pelvic segment and the trunk in patients with LBP and tighter and less
variable coordinated motion between the spinal segments over the whole gait cycle.
Although many researchers have sought to demonstrate differences in spinal motion
between pain–free and LBP subjects (Crosbie et al. 2013; Lamoth et al. 2006a,
2006b; Seay, Van Emmerik, and Hamill 2011), they have not suggested means to
relieve the LBP, such as changes in lumbopelvic motion during walking. Most
research has simply demonstrated differences in the lumbopelvic kinematics between
subjects with and without LBP during walking (Crosbie et al. 2013; Lamoth et al.
2006b; Seay, Van Emmerik, and Hamill 2011). Some studies have suggested
interventions to control lumbopelvic motion in subjects with LBP (Hoffman et al.
2011; Van Dillen et al. 2003); however, the effects of these interventions to control
lumbopelvic motion were not assessed in functional activities, such as walking.
Trunk muscles contribute to controlling lumbopelvic motion during walking
(Hanada, Johnson, and Hubley Kozey 2011; van der Hulst et al. 2010a, 2010b).
Normally, the ES muscle is activated in double support and relaxes during the period
of swing; however, in LBP, higher ES activities were observed, as a guarding
- 35 -
mechanism, in the whole stride cycle (Arendt Nielsen et al. 1996; van der Hulst et al.
2010a, 2010b). Additionally, van der Hulst de al. (2010a) reported that subjects with
chronic LBP showed increased activity of the ES and RA muscles, but there was no
significant difference in EO activity during any period of the stride compared with
healthy subjects. Although changes in trunk muscle activity have been demonstrated
in subjects with LBP compared with healthy control subjects, during walking, there is
insufficient evidence regarding which intervention influences trunk muscle activity
during walking in LBP.
Recently, there has been a growing consensus among clinicians and researchers
that LBP should be managed by classification–specific interventions in homogeneous
groups (Hoffman et al. 2011; O'Sullivan 2005; Sahrmann 2002; Van Dillen et al.
2003). Patients with mechanical LBP should be divided into several homogenous
subgroups, determined by the direction of the lumbar spine movement that evokes
pain and/or symptoms (Maluf, Sahrmann, and Van Dillen 2000; Sahrmann 2002). It
has been considered that specific management according to LBP subgroup can
improve pain relief. Several studies have demonstrated that classification–specific
movement control exercises could improve early and excessive lumbopelvic motion
and relieve pain by modifying lumbopelvic motion (Park et al. 2011; Scholtes et al.
2010; Smith, O'Sullivan, and Straker 2008). Although training and education to
control specific movement of the lumbar spine has been demonstrated to help prevent
and manage pain and symptoms, there has been no report that specific movement
control exercises affect lumbopelvic motion and trunk muscle activities during
- 36 -
walking.
Patients with a lumbar ExtRot pattern have difficulty in controlling the
lumbopelvic region towards lumbar extension and rotation during lower extremity
movements (Hoffman et al. 2011; Park et al. 2011; Sahrmann 2002). To resolve this
difficulty in patients with a lumbar ExtRot pattern, several specific movement control
exercises have been suggested: abdominal control in hook–lying, hip abduction and
lateral rotation in a supine position, hip extension with the knee extended, knee
flexion, and hip internal and external rotation in a prone position (Hoffman et al.
2011; Sahrmann 2002, Van Dillen et al. 2003). To date, there has been no report of
the effect of specific movement control exercises on lumbopelvic kinematics in
subjects with a lumbar ExtRot pattern during walking.
Thus, the purpose of this study was to assess the effects of specific movement
control exercises in subjects with a lumbar ExtRot pattern on 1) pain intensity,
disability, and fear avoidance in daily activities, and 2) lumbopelvic motion and trunk
muscle activities during walking.
- 37 -
Method
1. Design
This randomized, controlled trial was conducted in the Physical Therapy
Department of Yonsei University, Korea. Subjects visited the laboratory twice for
pre– and post–treatment assessments at an interval of 6 weeks. Before the pre–
treatment laboratory visit, each subject with LBP was screened by a physical therapist
for classification into a LBP subgroup according to the movement impairment
classification system. Through this classification examination, only subjects with a
lumbar ExtRot pattern were enrolled. The subjects with a lumbar ExtRot pattern were
allocated randomly to the experimental or control group.
- 38 -
2. Subjects
In total, 39 subjects (experimental group = 19; control group = 20) with LBP
participated (Figure 4). The inclusion criteria for LBP subjects were 1) more than 7
weeks continuing or recurrent LBP, and 2) pain localized from the costal margin to
above the inferior gluteal folds. To assess whether subjects showed a lumbar ExtRot
pattern, a physical therapist examined their lumbar motions and alignments in
response to several different tests, based on Sahrmann (2002). If subject responses
increased symptoms and/or pain with lumbar extension and rotation during trunk or
lower extremity movement, they were classified as the lumbar ExtRot pattern.
Selection of the subjects was performed by a physical therapist with training and
experience in assessing and treating related movement impairment in rehabilitation
programs. Exclusion criteria were 1) pain radiating to the leg or both legs with
neurological signs, 2) diagnosis of lumbar disc herniation, spinal deformity, or
fracture 3) having a history of back surgery, and 4) limitations in walking because of
a lower extremity injury. All participants signed an informed consent statement and
were supplied with information sheets prior to participation. The study was approved
by the Yonsei University Wonju institutional review board.
- 39 -
Figure 4. Flow chart for subject selection.
Excluded (n=43) Not meeting inclusion criteria (n=39) Declined to participate (n=4)
Allocated to experimental group (n=19) : Specific movement control exercises
Randomization
Subjects with low back pain (n=82)
Assessed for eligibility
Pre–treatment assessment (n=39)
Allocated to control group (n=20) : not applied
Post–intervention assessment (n=19)
Post–intervention assessment (n=17)
- 40 -
3. Measurements
3.1 Clinical Measures
A VAS was used to assess the severity and perception of the LBP experience
(Marshall, and Murphy 2010). VAS values range from 0 to 100. To assess disability
related to LBP, the modified ODI and Roland Morris disability questionnaire
(RMDQ) were used (Kim et al. 2005; Lee et al. 2011). The modified ODI
questionnaire consists of 10 items with six answers per item, and items are scored
from 0 to 5. The total score for each subject is presented as a relative value (total
possible score / total score × 100). The RMDQ consists of 24 items related to
limitations in activities of daily living. RMDQ values range from 0 (no disability) to
24 (maximum disability). The “Fear–avoidance beliefs questionnaire” (FABQ) was
used to explain how much fear and avoidance affected the subjects with LBP (Joo et
al. 2009; Waddell, and Burton 2005). The FABQ consists 16 items with a score range
each of 0–6. Higher scores indicate increased levels of fear–avoidance beliefs.
3.2 Kinematics and Surface Electromyography
Kinematic and surface EMG data were collected simultaneously during walking. A
three–dimensional motion–analysis system with six cameras (Vicon MX system,
Oxford Metrics, Oxford, UK) was used to determine events of the gait cycle (HS and
TO) and to measure lumbopelvic motion during gait. Twenty reflective markers (14–
- 41 -
㎜ circles) were attached to specific anatomical landmarks: lumbar markers (on the
spinous processes of T12 and L1, and 3 ㎝ on the left and right sides of the spinous
process of L1) and lower–extremity markers (bilaterally on the skin overlying the
anterior superior iliac spine, posterior superior iliac spine, lateral aspect of the thigh,
lateral epicondyle of the femur, lateral surface of the shank, lateral malleolus, second
metatarsal head, and the posterior midpoint of the calcaneus). All marker coordinates
were smoothed with a Woltring filter. Sampling rate was set at 100 ㎐.
Muscle activities of the abdominal muscles (RA, EO and IO) and the ES were
measured using a Noraxon TeleMyo 2400T instrument (Noraxon, Scottsdale, AZ,
USA). The surface EMG electrodes were attached to the RA (2 ㎝ lateral and 1 ㎝
superior to the umbilicus), EO (midway between the anterior superior iliac spine and
the rib cage), IO (1 ㎝ medial part to the anterior superior iliac spine) and ES (2 ㎝
lateral to the spinous process of L3) muscles. Sampling rate was set at 1000 ㎐. All
EMG data have 1st order high–pass filters was set to 10 ㎐ and low pass filters set to
1500 ㎐. All channels have 10th order low pass smoothing filters.
- 42 -
4. Procedure
All subjects walked on an 8–m–long straight walkway at their preferred speed.
Before testing, subjects are required to walk on the walkway until they had
familiarized themselves with walking conditions at a comfortable walking speed. To
collect kinematic and EMG data, subjects were asked to walk at least 12 times with a
rest of 30 s between trials.
- 43 -
5. Intervention
The treatment period was 6 weeks in duration. Subjects in the experimental group
were supervised individually with progressively more difficult exercise by a physical
therapist bi–weekly for 30 min. The completion of home exercise five times per week
was recorded over the 6 weeks. Specific movement control exercises consisted of 1)
education regarding the specific directions of movement in the lumbopelvic region
and postures thought to be associated with their LBP symptoms and 2) specific
movement control exercises (Appendix 1). Subjects were required to perform two sets
of 10 repetitions per day. All subjects in the experimental group were encouraged to
perform exercise without any symptom or pain during exercise periods. Although
subjects in the control group were also provided with general education regarding
neutral spinal alignment, spinal anatomy, and the causes of LBP at the pre–treatment
session; follow–up instructions were not provided.
- 44 -
6. Data Analysis
EMG and kinematic data were collected using Nexus 1.4 software and imported
into the Polygon software for data analysis. All data were averaged over 12 gait
cycles and normalized to one full stride from initial HS to the next HS in the same leg
(0–100 %). Gait parameters for HS and TO were determined by heel and second
metatarsal head markers, according to Pijnappels, Bobbert, and van-DieÃn (2001).
Spatio–temporal parameters (walking speed, cadence, step length, and step time) were
computed from the 3D kinematics. Three–dimensional angle of the lumbar spine and
pelvic region were analyzed using a global xyz–coordinate system. The pelvic
segment angle was defined relative to the global coordinate system. The lumbar angle
was defined relative to the pelvic segment. For statistical analyses, the angles of the
lumbar and pelvic segment in sagittal and transverse plane were used at the right HS,
left TO, left HS, and right TO.
The raw EMG data were processed using a root–mean–square algorithm. To
normalize the EMG activities of each subject, sub–MVIC tests were performed and
the EMG activity of the each muscle during walking was expressed as a percentage of
the sub–MVIC. For abdominal muscles (RA, EO, and IO), subjects were positioned
in a hook–lying position on a table, and were then required to lift both feet 1 ㎝ from
the table (Dankaerts et al. 2004). For ES muscle, subjects lay on their abdomens with
both knees at 90° flexion and then lifted both legs 5 ㎝ from the table (Dankaerts et
- 45 -
al. 2004). Sub–MVIC tests were performed with three trials in each position and the
EMG activities in the middle 3 s of the 5–s contraction were averaged. Mean EMG
activities of the RA, EO, IO, and ES were used for statistical analyses at the first
double support (from initial HS to left TO), left swing (from left TO to left HS),
second double support (from left HS to right TO), and right swing (from right TO to
right HS).
- 46 -
7. Statistical Analysis
SPSS version 21.0 (SPSS, Inc., Chicago, IL, USA) was used for all statistical
analyses. The Shapiro–Wilk test was conducted to ensure normal distribution of the
variables (spatiotemoral parameters, kinematic data of the lumbar spine and pelvis,
and EMG data of the trunk muscles). For non–parametric variables, the Mann–
Whitney U–test was used to evaluate between–group differences and the Wilcoxon
signed–ranks test was used to compare within–group variables between pre– and
post–intervention. For parametric variables, independent t–tests were used to compare
between–group differences and the paired t–test was used to compare variables
within–groups between pre– and post–intervention. An intention–to–treat analysis
was used, in which all subjects were analyzed in the group to which they were
originally assigned. Significance was set at p < 0.05.
- 47 -
Results
1. Subject Characteristics
Subject characteristics are listed in Table 5.
Table 5. Subjects’ characteristics
Parameter Experimental
(n =19)
Control
(n = 20) Statistic p
Gender (male/female) M=11/F=8 M=10/F=10 N/A N/A
Age (years) 23.05 ± 2.09a 23.35 ± 1.73 -0.485 0.630
Body mass (㎏) 63.00 ± 14.67 62.20 ± 10.14 0.199 0.843
Height (㎝) 171.95 ± 7.32 168.20 ± 8.02 1.522 0.137
Pain duration (months) 26.316 ± 19.15 20.50 ± 18.19 0.973 0.337 aMean ± standard deviation.
- 48 -
2. Clinical Measures
Table 6 shows the average values of the scores at baseline and after the 6–week
intervention. After the 6–week intervention, VAS, ODI, RMDQ, and FABQ scores
were decreased significantly from baseline in the experimental group (p < 0.05).
However, there was no significant difference in the VAS, ODI, RMDQ, or FABQ at
the 6–week follow–up in the control group (p > 0.05).
- 49
-
Tabl
e 6.
Cha
nges
in p
ain
inte
nsity
, dis
abili
ty, a
nd fe
ar a
void
ance
belie
fs a
fter 6
–wee
k in
terv
entio
n
Gro
upPr
e–in
terv
entio
nPo
st–i
nter
vent
ion
p
VA
Sa(㎜
)Ex
perim
enta
l40
.00
±15
.63e
15.7
9±
8.38
<0.
001*
Con
trol
39.0
0±
15.4
433
.50
±15
.28
0.09
1
Mod
ified
OD
Ib(%
)Ex
perim
enta
l11
.26
±5.
425.
05±
4.08
0.00
4*
Con
trol
12.9
0 ±
6.66
10.5
2±
6.44
0.06
7
RM
DQ
c(s
core
)Ex
perim
enta
l2.
42±
2.97
0.84
±0.
690.
017*
Con
trol
2.10
±1.
971.
52±
1.09
0.05
0
FAB
Qd
(sco
re)
Expe
rimen
tal
32.0
5±
15.8
721
.21
±13
.29
0.01
2*
Con
trol
34.1
0 ±
16.7
030
.73
±18
.30
0.07
9a V
AS:
vis
ual a
nalo
g sc
ale,
scor
ed fr
om 0
(no
pain
) to
10 (w
orst
pai
n).
b OD
I:O
swes
try d
isab
ility
inde
x, sc
ored
from
0 (n
o di
sabi
lity)
to 1
00 (h
igh
disa
bilit
y).
c RM
DQ
: Rol
and–
Mor
ris d
isab
ility
que
stio
nnai
re, s
core
d fr
om 0
(no
disa
bilit
y) to
24
(hig
h di
sabi
lity)
.d FA
BQ
: Fea
r–av
oida
nce
belie
fs q
uest
ionn
aire
, sco
red
from
0 (n
o av
oida
nce)
to 9
6 (s
ever
e fe
ar–a
void
ance
).e M
ean
±st
anda
rd d
evia
tion.
*p<
0.05
.
- 49 -
Table 6. Changes in pain intensity, disability, and fear avoidance beliefs after 6–week intervention
Group Pre–intervention Post–intervention p
VASa (㎜)Experimental 40.00 ± 15.63e 15.79 ± 8.38 < 0.001*
Control 39.00 ± 15.44 33.50 ± 15.28 0.091
Modified ODIb (%)Experimental 11.26 ± 5.42 5.05 ± 4.08 0.004*
Control 12.90 ± 6.66 10.52 ± 6.44 0.067
RMDQc (score)Experimental 2.42 ± 2.97 0.84 ± 0.69 0.017*
Control 2.10 ± 1.97 1.52 ± 1.09 0.050
FABQd (score)Experimental 32.05 ± 15.87 21.21 ± 13.29 0.012*
Control 34.10 ± 16.70 30.73 ± 18.30 0.079aVAS: visual analog scale, scored from 0 (no pain) to 10 (worst pain).bODI: Oswestry disability index, scored from 0 (no disability) to 100 (high disability).cRMDQ: Roland–Morris disability questionnaire, scored from 0 (no disability) to 24 (high disability).dFABQ: Fear–avoidance beliefs questionnaire, scored from 0 (no avoidance) to 96 (severe fear–avoidance).eMean ± standard deviation.*p < 0.05.
- 50 -
3. Spatio–temporal Parameters During Walking
Table 7 shows the spatiotemporal parameters at pre–intervention. There was no
significant difference in walking speed, cadence, or stride length between two groups
(p > 0.05). A significant difference between the experimental and control group in
stride time was identified (p < 0.05).
Table 7. Stride characteristics at pre–intervention
Stride characteristics Experimental
(n =19)
Control
(n = 20) p
Walking speed (㎧) 1.21 ± 0.23a 1.15 ± 0.11 0.344
Cadence (steps/min) 121.14 ± 16.50 113.48 ± 5.06 0.055
Stride time (s) 1.00 ± 0.10 1.06 ± 0.05 0.033*
Stride length (m) 1.23 ± 0.24 1.18 ± 0.10 0.474 aMean ± standard deviation. *p < 0.05.
- 51 -
4. Kinematics of Lumbopelvic Region
Table 8 shows mean values and standard deviations of the pelvic and lumbar angles
in the sagittal and transverse plane pre– and post–intervention of the two groups.
After the 6–week intervention, there was a significant decrease in the pelvic and
lumbar angles in the sagittal plane in the experimental group for all events (p < 0.05;
Figure 5 and 6). However, there was no significant difference in the lumbar or pelvic
angle in the transverse plane in the experimental group after the 6–week intervention
(p > 0.05; Figure 5 and 6). After the 6–week intervention, there was no significant
difference in the pelvic or lumbar angle in the sagittal or transverse plane in the
control group in any event (p > 0.05).
- 52
-
Tabl
e 8.
Pelv
ic a
nd lu
mba
r ang
lesi
n th
e sa
gitta
l and
tran
sver
se p
lane
s
Rig
htH
SaLe
ftTO
b
Mot
ion
Gro
upPr
ePo
stPr
ePo
st
Pelv
ic a
nter
ior t
iltin
gEx
perim
enta
l10
.58
±4.
64c
7.49
±2.
7210
.31
±4.
577.
46±
2.72
Con
trol
11.2
8±
2.93
12.7
0±
2.79
11.1
4±
2.87
12.5
5±
2.91
Pelv
ic ro
tatio
nEx
perim
enta
l3.
59±
3.50
4.91
±3.
352.
50±
4.35
4.35
±3.
78
Con
trol
3.23
±3.
433.
19±
2.34
3.09
±3.
192.
46±
2.45
Lum
bar e
xten
sion
Expe
rimen
tal
10.0
1±
6.93
6.69
±5.
7410
.48
±7.
067.
33±
5.80
Con
trol
10.3
2±
6.37
10.6
7±
8.34
11.0
1±
7.20
11.6
6±
8.70
Lum
bar r
otat
ion
Expe
rimen
tal
-.50
±2.
681.
13±
3.28
-0.3
0±
2.81
1.14
±3.
38
Con
trol
-.048
±4.
350.
79±
3.07
-0.2
5±
4.13
0.89
±3.
07a H
S: h
eel s
trike
.b TO
: toe
–off
.c M
ean
±st
anda
rd d
evia
tion
(°).
‘+’i
ndic
ates
cou
nter
cloc
kwis
e ro
tatio
nan
d ‘−’i
ndic
ates
clo
ckw
ise
rota
tion
inth
e tra
nsve
rse
plan
e.
- 52 -
Table 8. Pelvic and lumbar angles in the sagittal and transverse planes
Right HSa Left TOb
Motion Group Pre Post Pre Post
Pelvic anterior tiltingExperimental 10.58 ± 4.64c 7.49 ± 2.72 10.31 ± 4.57 7.46 ± 2.72
Control 11.28 ± 2.93 12.70 ± 2.79 11.14 ± 2.87 12.55 ± 2.91
Pelvic rotationExperimental 3.59 ± 3.50 4.91 ± 3.35 2.50 ± 4.35 4.35 ± 3.78
Control 3.23 ± 3.43 3.19 ± 2.34 3.09 ± 3.19 2.46 ± 2.45
Lumbar extensionExperimental 10.01 ± 6.93 6.69 ± 5.74 10.48 ± 7.06 7.33 ± 5.80
Control 10.32 ± 6.37 10.67 ± 8.34 11.01 ± 7.20 11.66 ± 8.70
Lumbar rotationExperimental -.50 ± 2.68 1.13 ± 3.28 -0.30 ± 2.81 1.14 ± 3.38
Control -.048 ± 4.35 0.79 ± 3.07 -0.25 ± 4.13 0.89 ± 3.07aHS: heel strike.bTO: toe–off.cMean ± standard deviation (°).‘+’ indicates counterclockwise rotation and ‘−’ indicates clockwise rotation in the transverse plane.
- 53 -
Table 8. (Continued)
Left HSa Right TOb
Motion Group Pre Post Pre Post
Pelvic anterior tiltingExperimental 10.80 ± 4.91c 7.85 ± 2.83 10.38 ± 4.86 7.51 ± 2.88
Control 11.48 ± 2.96 12.69 ± 3.04 11.20 ± 3.12 12.45 ± 3.20
Pelvic rotationExperimental -3.35 ± 5.18 -3.53 ± 3.39 -4.03 ± 3.21 -3.68 ± 3.68
Control -3.01 ± 4.92 -4.88 ± 3.21 -3.95 ± 3.95 -4.40 ± 3.22
Lumbar extensionExperimental 9.83 ± 7.30 6.03 ± 5.57 10.58 ± 7.12 6.98 ± 5.77
Control 9.43 ± 6.75 10.21 ± 8.07 10.47 ± 6.84 11.17 ± 8.13
Lumbar rotationExperimental -4.07 ± 4.38 -4.26 ± 3.16 -4.27 ± 4.41 -4.56 ± 3.26
Control -4.78 ± 4.27 -3.77 ± 2.68 -4.79 ± 4.45 -3.82 ± 2.75aHS: heel strike.bTO: toe–off.cMean ± standard deviation (°). ‘+’ indicates counter–clockwise rotation and ‘−’ indicates clockwise rotation in transverse plane.
- 53
-
Tabl
e 8.
(Con
tinue
d)
Left
HSa
Rig
htTO
b
Mot
ion
Gro
upPr
ePo
stPr
ePo
st
Pelv
ic a
nter
ior t
iltin
gEx
perim
enta
l10
.80
±4.
91c
7.85
±2.
8310
.38
±4.
867.
51±
2.88
Con
trol
11.4
8±
2.96
12.6
9±
3.04
11.2
0±
3.12
12.4
5±
3.20
Pelv
ic ro
tatio
nEx
perim
enta
l-3
.35
±5.
18-3
.53
±3.
39-4
.03
±3.
21-3
.68
±3.
68
Con
trol
-3.0
1±
4.92
-4.8
8±
3.21
-3.9
5±
3.95
-4.4
0±
3.22
Lum
bar e
xten
sion
Expe
rimen
tal
9.83
±7.
306.
03±
5.57
10.5
8±
7.12
6.98
±5.
77
Con
trol
9.43
±6.
7510
.21
±8.
0710
.47
±6.
8411
.17
±8.
13
Lum
bar r
otat
ion
Expe
rimen
tal
-4.0
7±
4.38
-4.2
6±
3.16
-4.2
7±
4.41
-4.5
6±
3.26
Con
trol
-4.7
8±
4.27
-3.7
7±
2.68
-4.7
9±
4.45
-3.8
2±
2.75
a HS:
hee
l stri
ke.
b TO: t
oe–o
ff.
c Mea
n ±
stan
dard
dev
iatio
n (°
). ‘+
’ind
icat
es c
ount
er–c
lock
wis
e ro
tatio
nan
d ‘−’i
ndic
ates
clo
ckw
ise
rota
tion
in tr
ansv
erse
pla
ne.
- 54 -
0
2
4
6
8
10
12
14
Experimental
* * * *
Rt. HS Lt. TO Lt. HS Rt. TO
Pelv
ic a
nter
ior t
iltin
g (d
eg)
0
2
4
6
8
10
12
14
ControlRt. HS Lt. TO Lt. HS Rt. TO
-8
-6
-4
-2
0
2
4
6
8
Experimental
Rt. HS Lt. TO Lt. HS Rt. TO
Pelv
ic ro
tatio
n (d
eg)
-8
-6
-4
-2
0
2
4
6
8
Pre-interventionPost-intervention
Control
Rt. HS Lt. TO Lt. HS Rt. TO
Figure 5. Comparison of the averaged pelvic angle in the sagittal and transverse
planes during walking between pre– and post–intervention. ‘+’ indicates
counter–clockwise rotation and ‘−‘ indicates clockwise rotation in
transverse plane (HS, heel strike; TO, toe–off). *p < 0.05 significantly
different between pre– and post– intervention within groups.
- 55 -
0
2
4
6
8
10
12
14
Experimental
* * * *
Rt. HS Lt. TO Lt. HS Rt. TO
Lum
bar
exte
nsio
n (d
eg)
0
2
4
6
8
10
12
14
Control
Rt. HS Lt. TO Lt. HS Rt. TO
-6
-5
-4
-3
-2
-1
0
1
2
3
Experimental
Rt. HS Lt. TO Lt. HS Rt. TO
Lum
bar r
otat
ion
(deg
)
-6
-5
-4
-3
-2
-1
0
1
2
3
Pre-interventionPost-intervention
Control
Rt. HS Lt. TO Lt. HS Rt. TO
Figure 6. Comparison of the averaged lumbar spine angle in the sagittal and
transverse planes during walking between pre– and post–intervention. ‘+’
indicates counter–clockwise rotation and ‘−‘ indicates clockwise rotation in
transverse plane (HS, heel strike; TO, toe–off). *p < 0.05 significantly
different between pre– and post– intervention within groups.
- 56 -
5. Electromyography Activities of Trunk Muscle
In the experimental group, right ES muscle activity decreased significantly during
first (p = 0.040) and second double support (p = 0.009) after the 6–week intervention
(Figure 7). The left ES also decreased significantly in the experimental group during
second double support (p = 0.014). There was no significant difference in either ES
muscle activity in the control group in any period (p > 0.05).
After the 6–week intervention, abdominal muscles (RA, EO, and IO) showed no
significant difference in any event in either group (p > 0.05; Figure 8, 9 and 10).
- 57 -
0
5
10
15
20
25
30
Experimental
**
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Rt E
S m
uscl
e ac
tivity
(% s
ub M
VIC
)
0
5
10
15
20
25
30
Control
Firstdouble support
Lt. swing Rt. swingSeconddouble support
0
5
10
15
20
25
30
Experimental
*
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Lt E
S mu
scle
activ
ity (%
sub M
VIC)
0
5
10
15
20
25
30
Pre-interventionPost-intervention
Control
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Figure 7. Comparison of the averaged ES muscle activities during walking between
pre– and post–intervention (MVIC: maximal voluntary isometric
contraction, ES: erector spine muscle). *p < 0.05 significantly different
between pre– and post–intervention within groups.
- 58 -
0
10
20
30
40
Experimental
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Rt R
A m
uscl
e ac
tivity
(% s
ub M
VIC
)
1 2 3 40
10
20
30
40
Control
Firstdouble support
Lt. swing Rt. swingSeconddouble support
0
10
20
30
40
50
60
Experimental
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Lt R
A m
uscl
e ac
tivity
(% s
ub M
VIC
)
1 2 3 40
10
20
30
40
50
60
Pre-interventionPost-intervention
Control
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Figure 8. Comparison of the averaged RA muscle activities during walking between
pre– and post–intervention (MVIC: maximal voluntary isometric
contraction, RA: rectus abdominis muscle).
- 59 -
0
10
20
30
40
50
60
Experimental
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Rt E
O m
uscl
e ac
tivity
(% s
ub M
VIC
)
0
10
20
30
40
50
60
Control
Firstdouble support
Lt. swing Rt. swingSeconddouble support
0
10
20
30
40
50
60
70
Experimental
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Lt E
O m
uscl
e ac
tivity
(% s
ub M
VIC
)
0
10
20
30
40
50
60
70
Pre-interventionPost-intervention
Control
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Figure 9. Comparison of the averaged EO muscle activities during walking between
pre– and post–intervention (MVIC: maximal voluntary isometric
contraction, EO: abdominal external oblique muscle).
- 60 -
0
20
40
60
80
100
Experimental
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Rt I
O m
uscl
e ac
tivity
(% s
ub M
VIC
)
0
20
40
60
80
100
Control
Firstdouble support
Lt. swing Rt. swingSeconddouble support
0
20
40
60
80
100
Experimental
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Lt I
O m
uscl
e ac
tivity
(% s
ub M
VIC
)
0
20
40
60
80
100 Pre-interventionPost-intervention
Control
Firstdouble support
Lt. swing Rt. swingSeconddouble support
Figure 10. Comparison of the averaged IO muscle activities during walking between
pre– and post–intervention (MVIC: maximal voluntary isometric
contraction, IO: abdominal internal oblique muscle).
- 61 -
Discussion
Various interventions to alleviate symptoms and pain in patients with LBP have
been investigated in the clinical and research settings (Hoffman et al. 2011, 2012;
Luomajoki et al. 2010; Van Dillen et al. 2003). Previous studies proposed that
improvements in movement patterns in the lumbopelvic region might help to reduce
the pain intensity and disability due to LBP (Scholtes, Gombatto, and Van Dillen
2009; Van Dillen et al. 2003). Also, it has been reported that specific movement
control exercises can decrease excessive lumbar spine movement during lower
extremity movement. Thus, in this study, the specific movement control exercises
were designed based on previous studies for subjects with the lumbar ExtRot pattern
and a 6–week intervention was applied to investigate whether the specific movement
control exercises for subjects with lumbar ExtRot pattern could alleviate pain
intensity, disability, and fear–avoidance behavior in daily activities. Additionally,
specific movement control exercises could alter the lumbopelvic kinematics and trunk
muscle activities during walking in patients with the lumbar ExtRot pattern. The
results have important implications in that it is the first reported study to (1)
demonstrate an effect of specific movement control exercises on pain intensity,
disability, and fear avoidance behavior in daily activities, and (2) show changes in the
pelvic and lumbar angle in the sagittal plane and ES muscle activities in subjects with
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the lumbar ExtRot pattern during walking after 6 weeks of movement control
exercises.
The exercises performed in this study were intended to change the movement and
alignment in the lumbopelvic region during walking in subjects with the lumbar
ExtRot pattern. Scholtes, Gombatto, and Van Dillen (2009) and Van Dillen et al.
(2003) reported that modifying the patient’s preferred lumbar spine movement or
alignment could improve their symptoms. However, because these studies assessed
the modification of the movement pattern in a single examination session, it is
difficult to demonstrate any long–term effect of modifying the movement pattern of
the lumbar spine on pain or symptoms in patients with LBP. Hoffman et al. (2011)
also demonstrated improvements in LBP through intervention based on the evaluation
of directional movement and alignment of the lumbar spine during a 3–month period,
but this was a single case report. In this study, subjects with the lumbar ExtRot
pattern performed five lumbopelvic control exercises (abdominal control in hook–
lying, hip abduction and lateral rotation in supine position, hip extension with knee
extended, knee flexion, and hip rotation in prone position) over 6 weeks. Improving
the ability to control excessive extension and rotation of the lumbar spine during
lower extremity movement may enable reducing pain–provoking movements of the
lumbar spine in daily activities, resulting in decreased pain intensity, disability, and
fear avoidance behavior in LBP subjects. Thus, the effects of the specific–movement
control exercise could be generalized in patients with a lumbar ExtRot pattern.
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Patients with mechanical LBP can be classified into subgroups according to
movement preferences in the lumbar spine towards a specific direction: flexion,
extension, rotation, or multidirectional (Hoffman et al. 2011). Subjects with the
lumbar ExtRot pattern are characterized by an excessive lordosis curve in standing
alignment and greater rotation and extension of the lumbar spine during lumbar spine
movement or with lower extremity movement (Sahrmann 2002; Van Dillen et al.
2003). In this study, after the 6–week exercise, subjects with the lumbar ExtRot
pattern showed a decreased angle of lumbar extension and pelvic anterior tilting at all
events (p < 0.05). This result could be explained in several ways. First, a change in
perception of the neutral position in the lumbopelvic region could help to maintain a
neutral lumbar position. The 6–week movement control exercise aimed to prevent
excessive lumbar extension and rotation during lower extremity movement as well as
education regarding perception of the neutral lumbar spine position. Thus, improving
the ability to adjust the alignment of the lumbopelvic region may influence changes in
the kinematics in the lumbar and pelvic region during walking. Second, after the 6–
week exercise program, decreased muscle activities in the ES of both sides may
contribute to decreases in lumbar extension and pelvic anterior angle. However, the
ES muscle activates anatomically to extend the lumbar spine, and patients with LBP
show greater activity in the ES by a pain–spasm mechanism, compared with healthy
subjects. After the 6–week exercise program, changes in ES muscle activation may
contribute to the decreased lumbar extension angle, which influences the decreased
intradiscal pressure and excessive loading at facet joint of the lumbar spine. Third,
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changes in the biomechanics may contribute to reduce excessive lumbopelvic
movement in sagittal plane. Unwanted and excessive pelvic anterior tilting and
rotation during lower extremity movement can be due to limitation of the flexibility
or length of the lower extremity muscles (e.g., rectus femoris, tensor fascial
latae/iliotibial, and iliopsoas muscles) (Hoffman et al. 2011; Kim et al. 2013; Park et
al. 2011; Sahrmann 2002). In this study, specific movement control exercises
consisted of lumbopelvic motion control during hip extension, rotation, and knee
flexion; it is possible that these exercises enabled control of the lumbopelvic region
during hip and knee movements through improving the flexibility of the muscles.
Walking is a cyclic and repetitive task, combined with hip and knee movements in the
sagittal plane. Thus, recovery from biomechanical limitation could help to prevent
unnecessary pelvic tilting and lumbar extension movement during walking.
Minimizing excessive directional movement of the lumbar spine could be an
important for rehabilitation and preventative programs for patients with LBP.
In many studies, the changes in muscle activities and motor control in patients with
LBP have been explained using a pain–spasm–pain model (Hodges, and Moseley
2003; van der Hulst et al. 2010a, 2010b). This model suggests that pain induces
continuous muscle activity and made muscle relaxation difficult. The present results
showed that activation of the right ES was decreased significantly at the first and
second double support phase, and the left ES was decreased significantly at the
second double support phase in the experimental group (p < 0.05). However, there
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was no significant difference in the activity of either ES muscle in the control group.
These findings suggest that ES muscle activities in subjects in the experimental group
were decreased by relaxation of muscle guarding with decreased pain after the 6–
week movement control exercise. Another reason for the decreased lumbar ES muscle
activity after the 6–week intervention might be increased activation of the deep
muscles with regard to spinal control. Hodges, and Moseley (2003) demonstrated
reduced muscle activity of the deep paraspinal muscles during functional activity in
patients with LBP, and van der Hulst et al. (2010) reported higher ES muscle activity
in patients with LBP, compared with healthy subjects. These results suggested that
the increased ES muscle activities were induced by compensatory muscle activation
resulting from a loss of deep muscle control, such as from the multifidus. In this study,
the specific movement control exercises were used to maintain lumbar spine stability
during lower extremity movement, which could contribute to activation of deep
muscles for further control of the lumbar spine. Although deep paraspinal muscles,
such as the multifidus muscle, were not examined in walking, the postulated
increased deep muscle control of the lumbar spine may reduce the activities of both
ES muscles.
Abdominal muscles make important contributions to spinal stability (Hanada,
Johnson, and Hubley Kozey 2011). Nevertheless, the abdominal muscles in each
phase showed no difference in either group after the 6–week intervention. High
variability in the IO, EO, and RA has been reported during walking, even with a
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normal gait (Saunders et al. 2005; White, and McNair 2002). Several studies have
reported that the RA, EO, and IO muscles showed mono activation, whereas other
studies demonstrated biphasic activation in walking (Saunders et al. 2005; White, and
McNair 2002). Potential alterations in abdominal muscle activity may result in
different levels of co–activation in the trunk muscle and variable lumbopelvic posture
across a population (Barton, Coyle, and Tinley 2009; White, and McNair 2002). Thus,
because of variability in abdominal muscle activation in walking, the 6–week
intervention did not result in a statistically significant difference in RA, EO, or IO
muscle activity while walking.
In this study, the kinematics of the lumbar spine and pelvic region in the transverse
plane did not change between pre– and post–intervention in either group. One
explanation for this might be the different conditions between the exercise position
and experimental task. In the experimental group, subjects performed all exercises in
a supine or prone position, which are open–chain exercises. However, walking, as the
experimental task, is a closed chain movement. Additionally, a walking task involves
multi–joint movements of the lower extremities, such as the ankle, knee, and hip.
Although movement control exercises for the experimental group were intended to
help control the motion of the lumbopelvic region with lower limb movement (hip
abduction–lateral rotation in supine, hip extension, hip internal/external rotation, and
knee flexion in prone position), it might be difficult for these exercises to control
rotation of the lumbopelvic region and prevent excessive movement in the transverse
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plane during walking. Future study is needed to determine whether specific gait
training to control the rotation of the pelvis and the lumbar spine can reduce motion in
the transverse plane during walking.
In this study, several potential limitations have been raised. First, because the all
participants were in their early and mid–20s, the results cannot be generalized to other
age groups. Second, subjects participating in this study were characterized by the
lumbar ExtRot pattern, so it is also difficult to generalize to other subgroups with
movement impairment, such as patients with lumbar flexion, flexion rotation, rotation,
and extension patterns. Future studies should examine the effects of specific
movement control exercises on the lumbopelvic kinematics and abdominal muscle
activities during walking in the other subgroups and diverse age groups.
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Chapter IV
Summary and Conclusion
Diagnosis and treatment based on a subclassification of the mechanical LBP type
has been emphasized in recent physical therapy practice. However, there has been no
reported study of differences in lumbopelvic motion and trunk muscle activities
during walking according to LBP subclassification and the effects of a specific
movement control intervention on lumbopelvic motion and trunk muscle activity
during walking in subjects with the lumbar ExtRot pattern. Thus, the first purpose of
this study was to compare the lumbopelvic motion and trunk muscle activity during
walking between subjects with and without the lumbar ExtRot pattern. Second, the
effects of a 6–week specific movement control exercise program on lumbopelvic
motion and trunk muscle activity during walking in subjects with the lumbar ExtRot
pattern were investigated. The results of this study showed a greater lumbar and
pelvic angle in the sagittal plane and ES muscle activities at all phases and lower right
IO muscle activity at the second double support phase during walking in subjects with
the lumbar ExtRot pattern, compared with subjects without the lumbar ExtRot pattern.
Additionally, through the 6–week specific movement control intervention, decreased
lumbar and pelvic angles in the sagittal plane and ES muscle activity were
demonstrated during walking in subjects with the lumbar ExtRot pattern. However,
there was no significant change in abdominal muscle activity (RA, EO, and IO) after
- 69 -
the 6–week intervention. Thus, the present study may help to guide clinical
assessments of lumbopelvic motion during walking and provide appropriate education
and rehabilitation programs for patients with LBP related to the lumbar ExtRot
pattern.
- 70 -
References
Anders C, Wagner H, Puta C, Grassme R, Petrovitch A, and Scholle HC. Trunk
muscle activation patterns during walking at different speeds. J Electromyogr
Kinesiol. 2007;17(2):245-252.
Arendt Nielsen L, Graven Nielsen T, Svarrer H, and Svensson P. The
influence of low back pain on muscle activity and coordination during gait:
a clinical and experimental study. Pain. 1996;64(2):231-240.
Barton CJ, Coyle JA, and Tinley P. The effect of heel lifts on trunk muscle
activation during gait: a study of young healthy females. J Electromyogr
Kinesiol. 2009;19(4):598-606.
Crosbie J, de Faria Negrão Filho R, Nascimento DP, and Ferreira P.
Coordination of spinal motion in the transverse and frontal planes during
walking in people with and without recurrent low back pain. Spine
(Philadelphia, Pa. 1976). 2013;38(5):E286-E292.
Dankaerts W, O'Sullivan PB, Burnett AF, Straker LM, and Danneels LA.
Reliability of EMG measurements for trunk muscles during maximal and
- 71 -
sub-maximal voluntary isometric contractions in healthy controls and
CLBP patients. J Electromyogr Kinesiol. 2004;14(3):333-342.
Hanada EY, Johnson M, and Hubley Kozey C. A comparison of trunk muscle
activation amplitudes during gait in older adults with and without chronic
low back pain. PM & R. 2011;3(10):920-928.
Harris-Hayes M, Van Dillen LR, and Sahrmann SA. Classification, treatment
and outcomes of a patient with lumbar extension syndrome. Physiother
Theory Pract. 2005;21(3):181-196.
Hodges PW, and Moseley GL. Pain and motor control of the lumbopelvic
region: effect and possible mechanisms. J Electromyogr Kinesiol.
2003;13(4):361-370.
Hoffman SL, Johnson MB, Zou D, Harris-Hayes M, and Van Dillen LR.
Effect of classification-specific treatment on lumbopelvic motion during
hip rotation in people with low back pain. [Randomized Controlled Trial].
Man Ther. 2011;16(4):344-350.
- 72 -
Hoffman SL, Johnson MB, Zou D, and Van Dillen LR. Gender differences in
modifying lumbopelvic motion during hip medial rotation in people with
low back pain. Rehabil Res Pract. 2012;635312.
Joo MK, Kim TY, Kim JT, and Kim SY. Reliability and Validity of the
Korean Version of the Fear-Avoidance Beliefs Questionnaire. J Korean
Acad Univ Trained Phys Therapists. 2009;16(2):24-30.
Kim DY, Lee SH, Lee HY, Lee HJ, Chang SB, Chung SK, and Kim HJ.
Validation of the Korean version of the oswestry disability index. Spine
(Phila Pa 1976). 2005;30(5):E123-E127.
Kim MH, Yi CH, Kwon OY, Cho SH, Cynn HS, Kim YH, Hwang SH, Choi
BR, Hong JA, and Jung DH. Comparison of lumbopelvic rhythm and
flexion-relaxation response between 2 different low back pain subtypes.
Spine (Phila Pa 1976). 2013;38(15):1260-1267.
Kim SH, Kwon OY, Park KN, and Kim MH. Comparison of erector spinae
and hamstring muscle activities and lumbar motion during standing knee
flexion in subjects with and without lumbar extension rotation syndrome. J
Electromyogr Kinesiol. 2013;23(6):1311-1316.
- 73 -
Lamoth CJ, Daffertshofer A, Meijer OG, and Beek PJ. How do persons with
chronic low back pain speed up and slow down? Trunk-pelvis coordination
and lumbar erector spinae activity during gait. Gait & posture.
2006a;23(2):230-239.
Lamoth CJ, Meijer OG, Daffertshofer A, Wuisman PI, and Beek PJ. Effects of
chronic low back pain on trunk coordination and back muscle activity
during walking: changes in motor control. Eur Spine J. 2006b;15(1):23-40.
Lee JS, Lee DH, Suh KT, Kim JI, Lim JM, and Goh TS. Validation of the
Korean version of the Roland-Morris Disability Questionnaire. Eur Spine J.
2011;20(12):2115-2119.
Lee M, Kim J, Son J, and Kim Y. Kinematic and kinetic analysis during
forward and backward walking. Gait & posture. 2013;38(4):674-678.
Luomajoki H, Kool J, de Bruin ED, and Airaksinen O. Improvement in low
back movement control, decreased pain and disability, resulting from
specific exercise intervention. Sports Med Arthrosc Rehabil Ther Technol.
2010;2:11.
- 74 -
Magalhaes MO, França FJ, Burke TN, Ramos LA, de Moura Campos
Carvalho e Silva AP, Almeida GP, Yuan SL, and Marques AP. Efficacy of
graded activity versus supervised exercises in patients with chronic non-
specific low back pain: protocol of a randomised controlled trial. BMC
Musculoskelet Disord. 2013;14;36.
Maluf KS, Sahrmann SA, and Van Dillen LR. Use of a classification system to
guide nonsurgical management of a patient with chronic low back pain.
Physical Therapy. 2000;80(11):1097-1111.
Maniadakis N, and Gray A. The economic burden of back pain in the UK.
Pain. 2000;84(1):95-103.
Marshall P, and Murphy B. Delayed abdominal muscle onsets and self-report
measures of pain and disability in chronic low back pain. J Electromyogr
Kinesiol. 2010;20(5):833-839.
O'Sullivan P. Diagnosis and classification of chronic low back pain disorders:
maladaptive movement and motor control impairments as underlying
mechanism. Man Ther. 2005;10(4):242-255.
- 75 -
O'Sullivan PB, Twomey L, and Allison GT. Altered abdominal muscle
recruitment in patients with chronic back pain following a specific exercise
intervention. J Orthop Sports Phys Ther. 1998;27(2):114-124.
Panjabi MM.The stabilizing system of the spine. Part I. Function, dysfunction,
adaptation, and enhancement. [Research Support, U.S. Gov't, P.H.S.]. J
Spinal Disord. 1992;5(4):383-389.
Park K, Cynn H, Kwon O, Lee W, Ha S, Kim S, and Weon J. Effects of the
abdominal drawing-in maneuver on muscle activity, pelvic motions, and
knee flexion during active prone knee flexion in patients with lumbar
extension rotation syndrome. Arch Phys Med Rehabil. 2011;92(9):1477-
1483.
Pijnappels M, Bobbert, MF, and van-DieÃn JH. Changes in walking pattern
caused by the possibility of a tripping reaction. Gait & posture.
2001;14(1):11-18.
Rasmussen-Barr E, Ang B, Arvidsson I, and Nilsson-Wikmar L. Graded
exercise for recurrent low-back pain: a randomized, controlled trial with 6-,
12-, and 36-month follow-ups. Spine (Phila Pa 1976). 2009;34(3):221-228.
- 76 -
Sahrmann SA. Diagnosis and Treatment of Movement Impairment Syndrome.
St. Louis, MO: Mosby Inc, 2002.
Saunders SW, Schache A, Rath D, and Hodges PW. Changes in three
dimensional lumbo-pelvic kinematics and trunk muscle activity with speed
and mode of locomotion. [Clinical Trial]. Clin Biomech (Bristol, Avon).
2005;20(8):784-793.
Scholtes SA, Gombatto SP, and Van Dillen LR. Differences in lumbopelvic
motion between people with and people without low back pain during two
lower limb movement tests. Clin Biomech (Bristol, Avon). 2009;24(1):7-12.
Scholtes SA, NortonBJ, Lang CE, and Van Dillen LR. The effect of within-
session instruction on lumbopelvic motion during a lower limb movement
in people with and people without low back pain. Man Ther.
2010;15(5):496-501.
Seay JF, Van Emmerik RE, and Hamill J. Influence of low back pain status on
pelvis-trunk coordination during walking and running. Spine (Philadelphia,
Pa. 1976). 2011;36(16):E1070-E1079.
- 77 -
Smith A, O'Sullivan P, and Straker L. Classification of sagittal thoraco-lumbo-
pelvic alignment of the adolescent spine in standing and its relationship to
low back pain. Spine (Philadelphia, Pa. 1976). 2008;33(19):2101-2107.
Trudelle-Jackson E, Sarvaiya-Shah SA, and Wang SS. Interrater reliability of
a movement impairment-based classification system for lumbar spine
syndromes in patients with chronic low back pain. [Evaluation Studies]. J
Orthop Sports Phys Ther. 2008;38(6):371-376.
van der Hulst M, Vollenbroek Hutten M, Rietman JS, and Hermens HJ.
Lumbar and abdominal muscle activity during walking in subjects with
chronic low back pain: support of the "guarding" hypothesis? J
Electromyogr Kinesiol. 2010a;20(1):31-38.
van der Hulst M, Vollenbroek Hutten M, Rietman JS, Schaake L, Groothuis
Oudshoorn KG, and Hermens HJ. Back muscle activation patterns in
chronic low back pain during walking: a "guarding" hypothesis. Clin J
Pain. 2010b;26(1):30-37.
van Dieën JH, Cholewicki J, and Radebold A. Trunk muscle recruitment
patterns in patients with low back pain enhance the stability of the lumbar
spine. Spine (Phila Pa 1976). 2003;28(8):834-841.
- 78 -
Van Dillen LR, Sahrmann SA, Norton BJ, Caldwell CA, McDonnell MK, and
Bloom N. The effect of modifying patient-preferred spinal movement and
alignment during symptom testing in patients with low back pain: a
preliminary report. Arch Phys Med Rehabil. 2003;84(3):313-322.
Vogt L, Pfeifer K, and Banzer W. Neuromuscular control of walking with
chronic low-back pain. Man Ther. 2003;8(1):21-28.
Vogt L, Pfeifer K, Portscher And M, and Banzer W. Influences of nonspecific
low back pain on three-dimensional lumbar spine kinematics in locomotion.
Spine (Philadelphia, Pa. 1976). 2001;26(17):1910-1919.
Waddell G, and Burton AK. Concepts of rehabilitation for the management of
low back pain. Best Pract Res Clin Rheumatol. 2005;19(4):655-670.
White SG, and McNair PJ. Abdominal and erector spinae muscle activity
during gait: the use of cluster analysis to identify patterns of activity. Clin
Biomech. 2002;17(3):177-184.
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국문 요약
허리 폄 돌림 패턴을 가진 대상자에게 특정 움직임
조절 운동이 걷기 시 허리골반 운동과 몸통 근육의
근활성도에 미치는 영향
연세대학교 대학원
물리치료학과
김 시 현
걷기 시 허리골반 운동과 몸통 근육의 근활성도 변화는 비 특이성 허리
통증을 호소하는 환자를 관리하기 위한 적응증이 될 수 있다. 첫 번째
연구에서는 허리 폄 돌림 패턴을 가진 대상자와 정상인들 사이에서 걷기
시 허리골반 운동과 몸통 근육의 근활성도를 비교하였다. 허리 돌림 폄
패턴을 가진 26 명의 대상자와 18 명의 정상인이 모집되었다. 다리와
허리에 20 개의 반사 마커를 부착하였고 3 차원 동작 분석기를 이용하여
허리골반의 운동을 관찰하였다. 몸통 근육인 척추세움근, 배곧은근,
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배바깥빗근, 배속빗근의 양쪽에 표면 전극을 부착하였고 표면 근전도
시스템을 이용하여 근활성도를 측정하였다. 실험에 참여한 모든 대상자는
편안한 속도로 실험실 내의 8 m 보도를 12 회 걸었다. 운동형상학
데이터는 최초의 발꿈치 딛기(heel strike, HS), 왼쪽 발가락 떼기(toe–off,
TO), 왼쪽 HS, 오른쪽 TO 시점에서 수집되었고, 근전도 데이터는 첫번째
양발 지지(double support), 왼쪽 다리 스윙(leg swing), 두 번째 양발
지지, 오른쪽 다리 스윙 구간에서 수집되었다. 통계분석은 두 집단간의
변수의 차이를 검정하기 위하여 정규분포 여부에 따라 만휘트니 검정 또는
독립 표본 t–검정을 실시하였다. 집단간 유의수준은 0.05 로 하였다.
통계분석 결과, 시상면에서의 골반 및 허리뼈 각도는 허리 폄 돌림 패턴을
가진 대상자에게서 전 구간에 걸쳐 유의하게 증가함을 보였다. 가로면에서
골반 및 허리뼈 각도는 두 집단간 유의한 차이를 보이지 않았다. 또한
허리 폄 돌림 패턴을 가진 대상자는 모든 구간에서 유의하게 증가한 양쪽
척추세움근의 근활성도를 보였고, 두 번째 양발 지지 구간에서 유의하게
감소한 오른쪽 배속빗근 근활성도를 보였다. 두 번째 양발 지지 구간에서
오른쪽 배속빗근의 근활성도를 제외한 양쪽 배근육(배곧은근, 배바깥빗근,
배속빗근)의 근활성도에서는 두 집단간 유의한 차이를 보이지 않았다.
두 번째 연구에서는 허리 폄 돌림 패턴을 가진 대상자에게 6 주간 특정
움직임 조절 운동이 걷기 시 허리골반 운동과 몸통 근육의 근활성도에
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미치는 효과를 보고자 하였다. 39 명의 허리 폄 돌림 패턴을 가진 연구
대상자들이 본 실험에 참여 하였다. 39 명의 연구 대상자는 무작위 할당을
통하여 실험군(19 명)과 통제군(20 명)으로 배정되었다. 실험군의 연구
대상자들은 6 주간 움직임 조절 운동을 시행하였고 점진적으로 운동의
난이도가 조절되었다. 허리 통증의 정도, 통증으로 인한 장애 정도, 두려움
회피반응 정도를 평가하기 위하여 시각 사상 척도, 수정된 Oswestry
허리기능 장애 설문지, Roland–Morris 허리기능 장애 설문지, 두려움–회피
반응 설문지를 사용하였다. 걷는 동안 골반 및 허리뼈의 운동형상학
데이터와 몸통의 근육 활성도 데이터를 수집하기 위하여 실험 실 내의 8
m 보도를 편안한 속도로 걷도록 하였다. 운동형상학 데이터는 최초의
오른쪽 HS, 왼쪽 TO, 왼쪽 HS, 오른쪽 TO 시점에서 수집되었고, 근전도
데이터는 첫 번째 양발 지지, 왼쪽 다리 스윙, 두 번째 양발 지지, 오른쪽
다리 스윙 구간에서 수집되었다. 데이터는 각 집단 내에서 치료 중재
전∙후 변수들 사이에 차이를 검정하기 위하여 정규분포 여부에 따라
윌콕슨 부호 순위 검정 또는 대응 표본 t–검정을 실시하였다. 유의 수준은
0.05 로 하였다. 6 주간 치료 중재 후 실험군에서 모든 구간에서 시상면의
골반 및 허리뼈 각도는 유의하게 감소하였고, 대조군에서는 유의한 차이를
보이지 않았다. 또한 가로면에서의 골반 및 허리뼈 각도는 양쪽 모든
집단에서 유의한 차이를 보이지 않았다. 근전도 데이터에서 실험군은
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오른쪽 척추세움근의 근활성도가 첫 번째와 두 번째의 양발 지지 구간에서,
왼쪽 척추세움근은 두 번째 양발 지지 구간에서 유의하게 감소하였다.
대조군에서 양쪽 척추세움근의 근활성도는 어느 구간에서도 유의한 차이를
보이지 않았으며 배근육(배곧은근, 배바깥빗근, 배속빗근)의 근활성도는
양쪽 모든 집단에서 유의한 차이를 보이지 않았다.
두 연구를 통하여 허리 폄 돌림 패턴을 가진 연구대상자들은 걷기 시
모든 구간에서 시상면의 과도한 허리골반 운동이 증명되었다. 또한 모든
구간에서 유의하게 증가된 척추세움근의 근활성도와 두 번째 양발 지지
구간에서 유의하게 감소한 오른쪽 배속빗근의 근활성도를 증명하였다.
이렇게 변화된 허리골반 운동과 척추세움근의 근활성도는 6 주간의 특정
움직임 조절 운동을 통하여 유의한 영향을 주었지만, 허리골반 돌림과
배근육의 근활성도에는 유의한 영향을 주지 못했다. 이와 같이 특정
움직임 조절 운동이 허리 폄 돌림 패턴을 가진 환자에게 시상면에서
과도한 허리골반 운동과 과도한 척추세움근의 근활성도를 감소시킬 수
있는 효과적인 운동으로 사료된다.
핵심 되는 말: 걷기, 근전도, 배복근, 척추세움근, 허리골반 운동, 허리
통증, 허리 폄 돌림 패턴.
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Appendix 1. Protocol for the movement control exercise
Exercise Position Procedure
Abdominal
control
Hook–lying Level 1. Pulling navel towards the spine.
Level 2. Lifting one leg from the ground with
alternate foot unsupported.
Level 3. Sliding one leg to extend the hip and
knee with other foot unsupported.
Level 4. One foot lifting and then extending
without the leg touching the supporting
surface with other foot unsupported.
Level 5. Both legs extending with the same
method as level 4.
Hip abduction–
lateral rotation
Supine Level 1. Bending one knee with the foot on the
floor and then moving the knee towards
the outside and away from the body.
Level 2. One leg hip abduction–lateral rotation
with straightened knee.
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Appendix 1. (Continued)
Exercise Position Procedure
Hip extension with
knee extended
Prone Lifting one leg off the table.
Progression: Increase of the hip extension
range of motion (only 10° hip extension).
Knee flexion Bending the knee.
Progression: Increase of the knee flexion range
of motion.
Hip internal and
external rotation
Bending the knee to 90° and then rotating the
hip inward and outward.
Progression: Increase of the hip rotation range
of motion.