PTA 110: Functional & Applied Anatomy Concorde Career College

Gait PTA 110: Functional & Applied

Anatomy

Concorde Career College

Overview It is not clear whether gait is learned or is

pre-programmed at the spinal cord level. However, once mastered, gait allows us to move around our environment in an efficient manner, requiring little in the way of conscious thought, at least in familiar surroundings.

Most fundamental human locomotion ◦ Bipedal ◦ Reciprocal movement behavior ◦ Symmetrical (displacement and timing)


Ambulation

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Gait Cycle Describes important events occurring between

two successive heel contacts of same limb Gait cycle is described as occurring between 0%

and 100% and includes 2 primary phases, the stance phase and the swing phase

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Stance Phase Heel contact

◦ The instant the lower limb contacts the ground (0% of gait cycle)

Foot flat◦ The period that the entire plantar aspect is on ground

(8% of gait cycle) Mid stance

◦ The point where the body’s weight passes directly over supporting lower extremity (30% of gait cycle)

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

The Gait Cycle The gait cycle consists of two periods:

stance and swing◦ The stance period

Constitutes approximately 60% of the gait cycle Describes the entire time the foot is in contact with the

ground and the limb is bearing weight Begins with the initial contact of the foot on the ground,

and concludes when the ipsilateral foot leaves the ground

The stance period takes about 0.6 sec during an average walking speed


Subdivisions of the Gait Cycle

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Stance Phase – cont’d Heel off

◦ The instant the heel comes off ground (40% of gait cycle) Toe off

◦ The instant the toe leaves ground (60% of gait cycle) Push off

◦ Describes combined actions of heel off and toe off, when stance foot is literally “pushing off” toward next step




Stance Phase Weight acceptance

◦ The weight acceptance task occurs during the first 10% of the stance period The loading response interval begins as one limb

bears weight while the other leg begins to go through its swing period. This interval may be referred to as the initial double stance period and consists of the first 0-10% of the gait cycle

Stance Phase Single Leg Support

◦ The middle 40% of the stance period is divided equally into mid stance and terminal stance The mid stance interval representing the first half of the

single limb support task, begins as one foot is lifted, and continues until the body weight is aligned over the forefoot

The terminal stance interval is the second half of the single limb support task. It begins when the heel of the weight bearing foot lifts off the ground and continues until the contralateral foot strikes the ground

Weight Transmission During Walking


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Swing Phase Early swing

◦ Period from toe off to mid swing (65% of gait cycle) Mid swing

◦ Period when foot of swing leg passes next to foot of stance leg (75% of gait cycle)

Late/Terminal swing◦ Period from mid swing until heel contacts ground (85% of

gait cycle)




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Additional Terminology of Gait

Step◦ Events occurring between successive heel contacts of

opposite feet Step length

◦ Distance traveled in one step Step width

◦ Distance between heel centers of two consecutive foot contacts


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Additional Terminology of Gait

Stride ◦ Events that take place between successive heel contacts

of same foot Stride length

◦ Distance traveled in one stride—two consecutive heel contacts of same foot



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Additional Terminology of Gait – cont’d

Cadence◦ Also called step rate, defined as number of steps

Walking velocity◦ Speed at which an individual walks


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Stance Phase: Heel Contact

Gait cycle beginning, when heel first contacts the ground

Center of gravity of body is at its lowest point Ankle is held in neutral dorsiflexion Ankle transitions toward foot-flat stance and the

ankle dorsiflexor muscles are eccentrically activated to assist with lowering the ankle into plantarflexion


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Stance Phase: Heel Contact – cont’d

The knee is slightly flexed, positioned to absorb shock of initial weight bearing

Quadriceps are eccentrically active to allow a slight “give” to the flexed knee and help prevent the knee from buckling

Hip extensors are isometrically active to prevent the trunk from jackknifing forward



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Stance Phase: Foot Flat Point in which the entire plantar surface of foot

contacts the ground Loading-response phase of gait Muscles and joints of lower limb assist with shock

absorption, as the lower extremity continues to accept increasing amounts of body weight


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Stance Phase: Foot Flat – cont’d

The ankle has just rapidly moved into 5-10 degrees of plantar flexion

Knee continues to flex to about 15 degrees, acting as a shock absorbing “spring”

Quadriceps continue to function eccentrically, and the hip extensors guide hip toward increasing extension



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Stance Phase: Mid Stance Occurs as the leg approaches vertical position Leg is in single-limb support, as the other limb is

freely swinging forward The ankle dorsiflexor muscles are inactive;

plantar flexor muscles are eccentrically active, controlling the rate at which the lower leg advances over the foot


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Stance Phase: Mid Stance – cont’d

Knee reaches near-fully extended position Hip abductors play an important role in stabilizing

the pelvis in the frontal plane, preventing the opposite side of pelvis from dropping excessively


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Stance Phase: Heel Off Occurs just after mid stance as the lower leg and

ankle begin “pushing off,” continuing to propel body forward

Begins as the heel breaks contact with the ground

Plantarflexor muscles and the Achilles tendon stretch in preparation for propulsion

At heel off, the plantarflexor muscles have switched their activation from eccentric to concentric


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Stance Phase: Heel Off – cont’d

Extended knee prepares to flex, usually driven by short burst of activity from the hamstring muscles

Hip continues to extend, ending in about 10 degrees of extension

Eccentric activation of hip flexors, particularly iliopsoas, help control the amount of hip extension that occurs


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Stance Phase: Toe Off Final event of stance phase of gait Toe off ends when toes break contact with the

ground Toes are in marked hyperextension at the

metatarsophalangeal joints, supported by activation of the intrinsic foot muscles

Ankle continues plantarflexing through concentric activation of plantarflexor muscles


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Stance Phase: Toe Off – cont’d

At toe off, knee is flexed 30 degrees, but hamstrings are only minimally active

Most knee flexion arises as a result of inertia produced, as hip is pulled into flexion

In final stage of toe off, hip is in nearly-neutral position, with thigh nearly perpendicular to ground


Stance Phase Limb Advancement

◦ Pre-swing. This interval begins with initial contact of the contralateral limb and ends with ipsilateral toe-off. As both feet are on the floor at the same time during this interval, double support occurs for the second time in the gait cycle.

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Swing Phase: Early Swing Leg begins to accelerate forward Plantarflexed ankle begins to dorsiflex, clearing

the ground as it is advanced forward Knee continues to flex, and hip flexors continue

to contract, pulling the extended thigh forward



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Swing Phase: Mid Swing Midpoint of swing phase Contralateral leg is in mid stance, supporting the

body weight Ankle is held in neutral position Knee is flexed about 50-60 degrees, helping

advance the lower limb Hip approaches 35 degrees of flexion, continuing

to be pulled forward through concentric hip flexor activation



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Swing Phase: Terminal Swing

Limb begins to decelerate in preparation for heel contact

Leg is placed well in front of body, preparing for transition to accept body weight

Ankle dorsiflexors are activated isometrically, positioning foot for heel contact

Knee has moved from flexed position of mid swing to almost full extension


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Swing Phase: Terminal Swing – cont’d

Hamstrings are active eccentrically at this time to slow rapidly extending knee

Hip flexor muscles become inactive in terminal swing

Hip extensors decelerate forward leg progression leg through eccentric activation



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Muscle and Joint Interactions in Frontal Plane

Abductor muscles play an important role in frontal plane hip stability

Without activation of hip abductors on the stance leg, the opposite side of pelvis would drop under the force of gravity, known as a positive Trendelenburg sign

Activation of the stance leg’s hip abductors holds the pelvis level


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Muscle and Joint Interactions in Frontal Plane – cont’d

Strong medial and lateral collateral ligaments of knee provide natural stability to knee in frontal plane

Loss of this stability may lead to issues such as genu valgus, potentially altering normal gait mechanics

Instability of knee may arise from impairments at hip or foot


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Muscle and Joint Interactions in Frontal Plane – cont’d

While walking, subtalar and transverse tarsal joints cooperate to transform the foot from pliable platform at early stance to more rigid platform at late stance

Position of supination arranges bones of foot to their most stable position, forming rigid lever for push-off


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Muscle and Joint Interactions in Horizontal Plane

Much of the lower limb control within the horizontal plane during walking occurs at hip and foot

During walking, the pelvis rotates in the horizontal plane about a vertical axis of rotation through hip joint of stance leg

Because the trunk remains relatively stationary during walking, the lumbar spine must rotate slightly to de-couple the rotating pelvis from thorax


Joint Motions in Gait Pelvis

◦ For normal gait to occur, the pelvis must both rotate and tilt

Joint Motions in Gait Sacroiliac Joint

◦ As the right leg moves through the swing period, the position of the right innominate changes from one of extreme anterior rotation at the point of pre-swing to a position of posterior rotation at the point of initial contact

◦ As the right extremity moves through the loading response to mid stance, the ilium on that side begins to convert from a posteriorly rotated position to a neutrally rotated position. From mid stance to terminal stance, the ilium rotates anteriorly, achieving maximum position at terminal stance

Joint Motions in Gait Sacroiliac Joint

◦ The sacrum rotates forward around a diagonal axis during the loading response, reaching its maximum position at mid stance (e.g., right rotation on a right oblique axis at right mid stance), and then begins to reverse itself during terminal stance

Joint Motions in Gait Hip

◦ Hip motion occurs in all three planes during the gait cycle

Knee ◦ The knee flexes twice and extends twice during

each gait cycle: once during weight bearing and once during non-weight bearing

Joint Motions in Gait Foot and ankle

◦ Ankle joint motion during the gait cycle occurs primarily in the sagittal plane At initial contact with the ground the ankle is dorsiflexed During the loading response interval, plantar flexion occurs at

the talocrural joint, with pronation occurring at the subtalar joint

At the end of the mid stance interval, the talocrural joint is maximally dorsiflexed, and the subtalar joint begins to supinate

From the mid stance to the terminal stance interval the foot is in supination

Once the ankle is fully close-packed, the heel is lifted by a combination of passive force and contraction from the taut gastrocnemius, and the soleus

Muscle Actions in Gait Spine and pelvis

◦ During the swing period, the semispinalis, rotatores, multifidus, and external oblique muscles are active on the side toward which the pelvis rotates

◦ The erector spinae and internal oblique abdominal muscles are active on the opposite side

◦ The psoas major and quadratus lumborum help to support the pelvis on the side of the swinging limb, while the contralateral hip abductors also provide support

Muscle Actions in Gait Knee

◦ During the swing period, there is very little activity from the knee flexors

◦ The knee extensors contract slightly at the end of the swing period prior to initial contact. During level walking the quadriceps achieve peak activity during the loading response interval (25% maximum voluntary contraction) and are relatively inactive by mid stance as the leg reaches the vertical position and ‘locks’, making quadriceps contraction unnecessary

Muscle Actions in Gait Hip

◦ During the early to mid portion of the swing phase, the iliopsoas is the prime mover with assistance from the rectus femoris, sartorius, gracilis, adductor longus, and possibly the tensor fascia latae, pectineus, and the short head of the biceps femoris during the initial swing interval

◦ In terminal swing, there is no appreciable action of the hip flexors when ambulating on level ground. Instead the hamstrings and gluteus maximus are strongly active to decelerate hip flexion and knee extension

Muscle Actions in Gait Hip

◦ The adductor magnus muscle supports hip extension and also rotates the pelvis externally toward the forward leg

◦ In mid stance, coronal plane muscle activity is greatest as the abductors stabilize the pelvis. The muscle activity initially is eccentric as the pelvis shifts laterally over the stance leg. The gluteus medius and minimus remain active in terminal stance for lateral pelvic stabilization

Muscle Actions in Gait Knee

◦ Hamstring involvement is also important to normal knee function. The co activation of the antagonist muscles about the knee during the loading response aid the ligaments in maintaining joint stability, by equalizing the articular surface pressure distribution, and controlling tibial translation.

Muscle Actions in Gait Foot and ankle

◦ During the beginning of the swing period, the tibialis anterior, extensor digitorum longus (EDL), extensor hallucis longus (EHL), and possibly the peroneus tertius contract concentrically with slight to moderate intensity tapering off during the middle of the swing period


◦ At the point where the leg is perpendicular to the ground during the swing period, the tibialis anterior, EDL and EHL group of muscles contract concentrically to dorsiflex and invert the foot in preparation for the initial contact


◦ Following initial contact, the anterior tibialis works eccentrically to lower the foot to the ground during the loading response interval

◦ Calcaneal eversion is controlled by the eccentric activity of the posterior tibialis, and the anterior movement of the tibia and talus is limited by the eccentric action of the gastrocnemius and soleus muscle groups as the foot moves towards mid stance

◦ Pronation occurs in the stance period to allow for shock absorption, ground terrain changes, and equilibrium


◦ The triceps surae become active again from mid stance to the late stance period contracting eccentrically to control ankle dorsiflexion as the COG continues to move forward

◦ In late stance period the Achilles tendon is stretched as the triceps surae contracts and the ankle dorsiflexes

◦ At this point the heel rises off the ground and the action of the plantar flexors changes from one of eccentric contraction, to one of concentric contraction

Characteristics of Normal Gait

Gait involves the displacement of body weight in a desired direction utilizing a coordinated effort between the joints of the trunk and extremities and the muscles that control or produce these motions

Any interference that alters this relationship may result in a deviation or disturbance of the normal gait pattern

Normal Gait Five priorities of normal gait:

◦ Stability of the weight bearing foot throughout the stance period

◦ Clearance of the non-weight bearing foot during the swing period

◦ Appropriate pre-positioning (during terminal swing) of the foot for the next gait cycle

◦ Adequate step length◦ Energy conservation

Walking Through the Life-Span

Infant-Child◦ Crawling◦ Toddler – not mature gait pattern ◦ About age 5 – mature gait pattern

Increase in absolute stride length Heel-toe pattern through foot flat to toe-off Narrowing base of support Control over terminal knee extension Full pelvic rotation Improved balance and postural alignment Reciprocal arm leg gait pattern

Walking Through the Life-Span

Older Adults ◦ Weakness, loss of ROM, decrease in sensory

motor control, decrease in balance control, postural misalignment Slower walking speed – shorter step length Increased stance phase Increase step width – larger base of support for

balance Increase fear of falling

Forward flexed close in visual tracking Encourage forward visual tracking

Gait Deviations


Influences on Gait Pain Posture Flexibility and the amount of available joint

motion Endurance - economy of mobility Base of Support Interlimb coordination Leg-length Gender Pregnancy

Influences on Gait Obesity Age Lateral and vertical displacement of the

COG Properly functioning reflexes Vertical Ground Reaction Forces Medial-Lateral Shear Forces Anterior-Posterior Shear Forces

Abnormal Gait Syndromes In general gait deviations fall under four

headings: ◦ Those caused by weakness◦ Those caused by abnormal joint position or range

of motion◦ Those caused by muscle contracture◦ Those caused by pain

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Foot Slap On heel strike, foot quickly

drops into plantar flexion, producing a slapping sound as forefoot impacts ground

Impairment◦ Weakness of dorsiflexors ◦ May follow injury to common

peroneal nerve or hemiplegia


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Reason for deviation◦ Inadequate strength in dorsiflexor muscles to

slowly control plantar flexion following heel contact

◦ http://www.youtube.com/watch?v=g8FIM4hQtfU

Foot Slap


http://www.youtube.com/watch?v=g8FIM4hQtfU

http://www.youtube.com/watch?v=g8FIM4hQtfU

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High Stepping Gait Individual appears to be

stepping over an imaginary obstacle; initial foot contact is typically made with forefoot or entire plantar surface of foot

Impairment◦ Marked weakness of dorsiflexors

—resulting in “foot drop”◦ Possibly following injury to

common peroneal nerve or hemiplegia


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High Stepping Gait Reason for deviation

◦ In order to clear foot from ground, hip and knee must be excessively flexed to advance leg

http://www.youtube.com/watch?v=JLxKFL4CiAo http://www.youtube.com/watch?v=ny0b_Audmak


http://www.youtube.com/watch?v=JLxKFL4CiAo

http://www.youtube.com/watch?v=ny0b_Audmak

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Hip Circumduction Swing leg is advanced in

semi-circle arc Impairment

◦ Inability to “shorten” swing leg, possibly due to reduced active or passive hip or knee flexion or as a result of wearing a “straight-leg” brace at knee


Hip Circumduction Reason for deviation

◦ Circumduction creates extra clearance to advance functionally “long leg”

http://www.youtube.com/watch?v=mxyC-26RN60


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Excessive elevation of pelvis on “swing” side

Impairment◦ Inability to functionally

“shorten” swing-leg◦ Possibly due to weak hip

flexor muscles

Hip Hiking


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Reason for deviation◦ Elevating or “hiking” pelvis provides extra

clearance for advancing leg ◦ http://www.youtube.com/watch?v=mxyC-26RN60

Hip Hiking



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Weak Gluteus Maximus Gait

Backward lean of trunk during foot-flat phase

Impairment◦ Weakness of hip extensors

—gluteus maximus Reason for deviation

◦ Leaning backward during stance phase shifts body’s line of gravity posterior to hip, reducing need for active hip extension torque


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Walking with Hip and/or Knee Flexion Contracture Flexed position of hip and

knee during stance phase of gait, often referred to as a “crouched gait”

Impairment◦ Hip or knee flexion contracture

Reason for deviation◦ Increased tightness in tissues

that allow hip and knee extension


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Weak Hip Abductor Gait During single-limb support, pelvis and trunk lean

excessively to opposite (uncompensated) or same (compensated) side as weak hip abductor muscles

Impairment◦ Weakness of hip abductor muscles

Reason for deviation◦ “Uncompensated” response: hip abductors of stance leg

are unable to produce enough force to hold pelvis level◦ “Compensated” response: purposely leaning trunk and

pelvis to same side as weak muscles shifts line of gravity closer to stance hip


Abnormal Gait Syndromes Trendelenburg Gait

◦ This type of gait is due to weakness of the hip abductors (gluteus medius and minimus)

◦ The normal stabilizing affect of these muscles is lost and the patient demonstrates an excessive lateral list in which the trunk is thrust laterally in an attempt to keep the center of gravity over the stance leg


Trendelenburg Gait

http://www.youtube.com/watch?v=b5rIEx9SsCo

Weak Hip Abductor Gait



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Vaulting Individual rises up on toes of

stance foot while swinging contralateral leg forward

Impairment◦ Any impairment of lower extremity

that reduces ability to functionally reduce length of limb


Reason for deviation◦ Standing on tiptoes creates extra clearance for

contralateral leg to clear ground during swing◦ http://www.youtube.com/watch?v=i2bxODibvb0

Vaulting

http://www.youtube.com/watch?v=i2bxODibvb0

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Weak Quadriceps Gait Knee remains fully

extended throughout stance, combined with excessive forward lean of trunk

Impairment◦ Weakness or avoidance of

activation of quadriceps muscle

Reason for deviation◦ Forward lean of trunk shifts

line of gravity anterior to medial-lateral axis of knee


Abnormal Gait Syndromes Equinus Gait

◦ Equinus gait (toe-walking), one of the more common abnormal patterns of gait of patients with spastic diplegia, is characterized by forefoot strike to initiate the cycle and premature plantar flexion in early stance to midstance

◦ http://www.youtube.com/watch?v=MMM8Tqntbzo◦ http://www.youtube.com/watch?v=eLuxTFHoZAA

http://www.youtube.com/watch?v=MMM8Tqntbzo

http://www.youtube.com/watch?v=MMM8Tqntbzo

http://www.youtube.com/watch?v=eLuxTFHoZAA

http://www.youtube.com/watch?v=eLuxTFHoZAA

Abnormal Gait Syndromes Ataxic Gait

◦ The ataxic gait is seen in two principal disorders: cerebellar disease (cerebellar ataxic gait) and posterior column disease (sensory ataxic gait)

◦ http://www.youtube.com/watch?v=FpiEprzObIU

http://www.youtube.com/watch?v=FpiEprzObIU

http://www.youtube.com/watch?v=FpiEprzObIU

Abnormal Gait Syndromes Parkinsonian Gait

◦ The parkinsonian gait is characterized by a flexed and stooped posture with flexion of the neck, elbows, metacarpophalangeal joints, trunk, hips, and knees

◦ The patient has difficulty initiating movements and walks with short steps with the feet barely clearing the ground. This results in a shuffling type of gait with rapid steps

◦ http://www.youtube.com/watch?v=j86omOwx0Hk

http://www.youtube.com/watch?v=j86omOwx0Hk

http://www.youtube.com/watch?v=j86omOwx0Hk

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Genu Recurvatum Excessive hyperextension

of knee during stance phase of gait

Impairment◦ A: Quadriceps and/or

knee flexor paralysis◦ B: Plantar flexion

contracture


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Genu Recurvatum: Reasons for Deviation

A: Overstretched posterior capsule of knee and/or paralysis of muscles that cross posterior side of knee (hamstrings) fail to limit knee extension

B: Leg deviates posteriorly relative to ankle and forces knee into hyperextension, eventually overstretching posterior capsule

http://www.youtube.com/watch?v=MUkCGd6sg1M


http://www.youtube.com/watch?v=MUkCGd6sg1M


Propulsive Gait - a stooped, rigid posture with the head and neck bent forward

Scissors Gait - legs flexed slightly at the hips and knees, giving the appearance of crouching, with the knees and thighs hitting or crossing in a scissors-like movement ◦ http://www.youtube.com/watch?v=UDgxjRyPe2w

Abnormal Gait Patterns

http://www.youtube.com/watch?v=UDgxjRyPe2w

Antalgic Gait Pain (Antalgic) Gait Pattern

◦ Pain promotes a modification of the gait pattern to avoid joint motions, muscle contraction and weight bearing that sustains or increase the pain

◦ The resulting pattern is termed antalgic gait pattern Changes in gait symmetry – timing and movement Patient should not ambulate “through the pain”

Increases guarding Promotes abnormal movement patterns Produces abnormal forces through joint structures Uses much more energy Irritates, inflames and can damage painful involved

areas

Documents

PTA 110: Functional & Applied Anatomy Concorde Career College