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Physical Therapy in Sport 9 (2008) 40–51

www.elsevier.com/locate/yptsp

Masterclass

A new perspective on risk assessment

Sarah Mottram�, Mark Comerford

Performance Stability, Lower Mill Street, Ludlow, Shropshire SY8 1BH, UK

Received 12 July 2007; received in revised form 4 November 2007; accepted 9 November 2007

Abstract

Pre-season screening is routinely promoted as part of either an injury risk management strategy or as a performance enhancement

strategy. Many of these processes focus on testing joint range, muscle strength (both power and endurance) and testing muscle

extensibility. Although some functional tests based on work specific tasks and sport specific skills are applied they are specific to one

task or a sport specific skill. It seems that the clinical outcomes of asymptomatic function, normal range of joint motion (isolated

testing) and normal muscle strength (isolated testing) are not adequate rehabilitation end points to prevent recurrence. This

Masterclass explores assessment and retraining from a new perspective in an attempt to address multiple muscle interactions acting

on multiple joints in functionally orientated tasks. The assessment is based on the specific assessment of the site and direction of

uncontrolled movement, under low and high threshold loading at different joint systems within functionally orientated tasks. From

this assessment, a specific retraining programme can be developed and implemented.

r 2007 Elsevier Ltd. All rights reserved.

Keywords: Risk assessment; Performance; Core Stability

1. Background

Pre-season screening of athletes is now common placein elite and professional sport and in competitive sporteven at junior levels. This screening is promoted as partof either an injury risk management strategy or as aperformance enhancement strategy.

The development of risk assessment and screeningprocesses and subsequent training packages for sport isof interest to therapists involved in sport (Bahr &Holme, 2003; Fuller & Drawer, 2004; MacAuley, 2000;McKeag & Sallis, 2000). Until now, the focus has beenon testing joint range, muscle strength (both power andendurance) and testing muscle extensibility (Bennell,Tully, & Harvey, 1999; Bennell, Wajswelner, Lew,Schall-Riaucour, Leslie, & Cirone, 1998; Gabbe, Finch,Bennell, & Wajswelner, 2005; Garrick, 2004; Kibler,Press, & Sciascia, 2006; Leetun, Ireland, Willson,Ballantyne, & McClay Davis, 2004). Assessing these

ee front matter r 2007 Elsevier Ltd. All rights reserved.

sp.2007.11.003

ing author. Tel.: +44 1584 877987.

ess: sarah@performance-stability.com (S. Mottram).

parameters invariably tends to isolate the individualjoints or muscles in non-functional ‘standard’ situations.Some attempts have focused on developing functionaltests based on work specific tasks and sport specificskills. When functionally orientated tests are used theytend to be highly specific to one task or sport specificskill (Bennell et al., 1999; Chek, 2004; Hewett, Myer,Ford, & Slauterbeck, 2006; McGill, Childs, & Lieber-man, 1999; Myer, Ford, Hewett, & Slauterbeck, 2004;Nadler, Malanga, Feinberg, Bubanni, Moley, & Foye,2002; Parkkari, Kujala, & Kannus, 2001).

All these parameters have been relatively unsuccessfulat predicting risk of injury. There is almost no reliableevidence base to support the use of screening forphysical factors to either predict risk of injury to preventinjury in the systematic review or meta-analysis data-bases (Chalmers, 2002; Wingfield, Matheson, & Meeu-wisse, 2004). Currently, the research evidence points to ahistory of previous injury being the most consistent andreliable predictor of high risk of re-injury (Fuller &Drawer, 2004; Joy, Paisley, Price, Rassner, & Thiese,2004; Locke, 2003; Reed, 2004; Van Mechelen, Hlobil,

ARTICLE IN PRESS

Table 1

Key features of the Performance Matrix

� Tests motor control efficiency of movement (site and direction of

uncontrolled movement) rather than just individual strength or

flexibility parameters

� Uses functional multi-joint tasks and identifies any uncontrolled

joint in the chain rather than testing individual joints or muscles

isolated from functional situations

� Functionally orientated tasks that are generic rather than sport

skill or task specific and can be applied to any sport or work

screening process

� Screens for both motor control (low threshold) and strength and

speed (high threshold) deficiencies to identify weak links

� Identifies performance assets that can be progressed more rapidly

or ‘fast tracked’ in training

S. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–51 41

& Kemper, 1992; Van Mechelen, Twisk, Molendijk,Blom, Snel, & Kemper, 1996; Watson, 2001). If this isthe case, then clearly there is a problem in the way thatwe are managing the previous injury. It seems that theclinical outcomes of asymptomatic function, normalrange of joint motion (isolated testing) and normalmuscle strength (isolated testing) are not adequaterehabilitation end points to prevent recurrence.

Screening questionnaires currently include some or allof the following factors: health questionnaire includingmedical conditions and history of previous injury andmanagement, lifestyle questionnaire including occupa-tional, recreational and personal variables, nutritionalevaluation, physical assessment and psychological pro-file (Emery, 2005; Galambos, Terry, Moyle, & Locke,2005; Junge, 2000; Locke, 2003; Peltz, Haskell, &Matheson, 1999; SMA, 2005). Physical assessmentrecommendations are currently advocated by authorsof many screening programmes. These include move-ment based parameters such as quick functional screen-ing e.g. Gray Cook’s—Functional Movement Screen(Cook, 2002), baseline measures of strength in theprimary power muscle groups, joint range, flexibility,power and elastic potential (Hewett et al., 2006).Physiology based parameters include cardiovascularfitness and recovery and sport specific protocols(Parkkari et al., 2001).

Assessment of ‘real’ function, that is, the influence ofthe multiple muscle interactions acting on multiple jointsin functionally orientated tasks has yet to be under-taken. This Masterclass explores assessment and retrain-ing from a new perspective in an attempt to address ‘realfunction’. The assessment is based on the specificassessment of the site and direction of uncontrolledmovement, under low and high threshold loading atdifferent joint systems within functionally orientatedtasks. It utilises multi-joint tasks that are generic (nottask or sport specific) and are related to both low andhigh load movement functions. The testing does notfocus excessively on testing individual muscles or joints.This testing process identifies a specific joint system as a‘weak link’ demonstrating uncontrolled movement,within a chain of linked joints in functional multi-jointtasks.

Fig. 1. Relative flexibility of the lumbar spine compensation into extension. (

be approximately 1200 knee flexion without significant lumbo-pelvic motio

Woolsey et al 1988): The relatively more flexible abdominals compensate

producing excessive anterior tilt and lumbar extension (reproduced with per

1.1. Evidence of uncontrolled movement

In the pain-free state, normal postural control andnon-fatiguing functional movements demonstrate effi-cient recruitment of the deep segmental muscles thatprovide a stability role. While high load or high speedactivities demonstrate dominance of superficial multi-joint muscles that provide a mobility (high load, largerange or high speed) role (Hodges, 2003; Hodges &Moseley, 2003).

There is evidence in the literature that chronicity/recurrence of symptoms is linked with dysfunction incontrol of movement (Dankaerts, O’Sullivan, Straker,Burnett, & Skouen, 2006; Hodges & Moseley, 2003;Hungerford, Gilleard, & Hodges, 2003; O’Sullivan,2005). There is strong evidence linking motor controldeficiencies in deep (force inefficient) local stabilitymuscles, which control inter-segmental movement, topain and recurrence (Hodges & Moseley, 2003; Jull,2000; Moseley & Hodges, 2006; Richardson, Hodges, &Hides, 2004; Sterling, Jull, Vicenzino, Kenardy, &Darnell, 2005). However, the evidence to supportassessing local stability muscles as part of routinescreening is poor unless there is a previous history ofpain in that region (Hodges & Moseley, 2003; Moseley& Hodges, 2006). Many authors have proposed thatthere is a link between pain being provoked by aparticular direction of movement (e.g. low back pain

a) Prone Knee Flexion(adapted Sahrmann 2002). Ideally, there should

n. (b) Lumbar extension weak link (Prone Knee Flexion) (adapted

for relatively stiffer hip flexors (rectus femoris resists knee flexion),

mission from KC International).

ARTICLE IN PRESSS. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–5142

provoked by forward bending) and motor controldeficiencies of the muscles that control that movement(Comerford & Mottram, 2001b; Dankaerts, O’Sullivan,Burnett, & Straker, 2006; Falla, Jull, & Hodges, 2004;Janda, 1996; O’Sullivan, 2005; O’Sullivan et al., 2006;Sahrmann, 2002).

Studies looking at the patterns of recruitment between1 joint (stabiliser) and multi-joint (mobiliser) synergists

T H R E S H O L D

D

I

R

E

C

T

I

O

N S I T E

T H R E S H O L D

Flexion

Extension

Rotation

Sidebend

Abduction

Adduction

Low

High

UN LN SB SJ LB/P H LL

Fig. 2. The Performance Matrix reproduced with permission from

Performance Stability. The Performance Matrix tests for

1. The site of the weak link, where the performance deficit is:

� upper neck (UN)

� lower neck (LN)

� upper back (UB)

� shoulder blade (SB)

� shoulder joint (SJ)

� low back/pelvis (LB/P)

� hip (H)

� lower leg (LL)

2. The direction of uncontrolled movement at the weak link. which

direction (3 cardinal planes) of loading is poorly dissociated that is,

the direction that is difficult to prevent or resist movement into:

� axial plane

J rotation (spine, limbs and scapula), winging (scapula)

� sagittal plane:

J flexion and extension (limbs and spine), posterior tilt and

anterior tilt (pelvis), elevated and forward tilt (scapula),

forward glide (hip and gleno-humeral translation)

� coronal plane:

J sidebend (spine), lateral tilt (pelvis), abduction and adduc-

tion (limbs), depression and retraction (scapula)

3. The threshold of loading failure

� whether the weak link is related to a motor control deficit or to

a strength deficit:

J low threshold motor control failure (low load and slow)

J high threshold weakness (high load or fast)

in non-symptomatic subjects have observed that the onejoint stabiliser synergists are dominant in non fatiguingfunctional movement and postural control tasks(Hodges & Moseley, 2003; Jull, 2000; O’Sullivan et al.,2006; Sterling, Jull, & Wright, 2001). In the presence ofchronic or recurrent musculo-skeletal pain subjectsemploy strategies or patterns of muscle recruitment thatare normally reserved for high load function (multi-jointmobiliser muscle dominance) to perform low loadpostural control and normal non-fatiguing functionalmovements (Dankaerts, O’Sullivan, Burnett et al., 2006;Falla, Bilenkij, & Jull, 2004; Falla, Jull, & Hodges, 2004;Hodges, 2003; Hodges & Moseley, 2003; Jull, 2000; Lee,1999; Moseley & Hodges, 2006; O’Sullivan, 2005;O’Sullivan et al., 2006; Richardson et al., 2004;Sahrmann, 2002; Sterling et al., 2001, 2005). There is

Table 3

High load multi-joint function testing categories in the Performance

Matrix reproduced with permission from Performance Stability

High load testing

categories

Identifies high load failure

6. Crook lying–

limb loading

Weak links associated with spinal, pelvic and

shoulder girdle control during limb

movements

7. Modified push-

up

Weak links associated with spinal control and

girdle control during upper and lower limb

weight transfer

8. Standing

shoulder loading

Weak links associated spinal and girdle

control during high force and high speed arm

movement

9. Lunge loading Weak links associated spinal girdle and lower

limb control during high force and high speed

leg movement

10. Explosive

propulsion

Weak links associated spinal girdle and lower

limb control during high force and high speed

leg movement

Table 2

Low load multi-joint function testing categories in the Performance

Matrix reproduced with permission from Performance Stability

Low load testing

categories

Identifies low load failure

1. Standing small knee

bend control

Weak links associated with spinal, girdle

and lower limb during bilateral and single

leg stance

2. Sitting spinal

dissociation

Weak links associated with spinal control

during lumbar thoracic and cervical

movements

3. Standing arm

control

Weak links associated shoulder girdle

control during arm movement

4. Crook lying limb

control

Weak links associated with lumbo-pelvic

control during limb movements

5. Hands and knees

limb control

Weak links associated with spinal, pelvic

and shoulder girdle control during limb

movements

ARTICLE IN PRESSS. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–51 43

little objective evidence for the measurement of uncon-trolled movement under high load testing. This ispartially due to the observation that to lift or push amaximal load or weight proximal spinal or girdlemovement normally increases to improve the mechan-ical efficiency of lifting or pushing heavy weights. Thepoint or threshold at which normal movement becomesuncontrolled movement under high load testing has notyet been determined.

1.2. Altered control strategies

These altered strategies or patterns have beendescribed in the research and clinical literature as‘substitution strategies’, ‘compensatory movements’,‘muscle imbalance’ between inhibited/lengthened stabi-lisers and shortened/overactive mobilisers, ‘faulty move-ments’, ‘abnormal dominance of the mobilisersynergists’, ‘co-contraction rigidity’ and ‘control impair-ments’.

Making the link between altered control strategiesand pain is not new but the concept of linking it toinjury prevention is (Schwellnus, 2004). This is ofparticularly interest as in the presence of chronic orrecurrent musculo-skeletal pain these altered strategieshave been shown to be reversible (O’Sullivan, 2005).

1.3. Relative flexibility

These altered control strategies have been linked withthe concept of relative flexibility (Comerford & Mot-tram, 2001b; Janda, 1996; Sahrmann, 1987, 2002). It isfrequently observed that a loss of range of movement at

Fig. 3. Test 1F: Single leg small knee bend+lunge & lean (see scoring

one or more motion segments is matched by thedevelopment of compensatory movement at an adjacentsegment. This has been described as relative stiffness andrelative flexibility (Sahrmann, 2002). The relative stiff-ness is commonly observed in the dominant multi-jointmobility muscle synergists and the relative flexibility inthe inefficient one joint stability muscle synergists.During multi-joint movements, a relatively stiffersegment tends to resist movement, but function ismaintained by developing compensatory movement atthe less stiff (relatively flexible) segment. The concept ofrelative flexibility has been linked to uncontrolledmovement and pain and pathology by causing directionrelated stress and strain (Comerford & Mottram, 2001b;Sahrmann, 2002).

The ability to compensate for restrictions to keepfunction is normal adaptive behaviour in the movementsystem. This is not abnormal as long as motor controlstrategies within the central nervous system can controlthis movement when required. Compensation forrestriction (relative flexibility) should be considered tobe maladaptive behaviour when the central nervoussystem lacks the ability to control or prevent thecompensation when required. The assessment of thisuncontrolled movement can be described in terms of thesite and direction of uncontrolled compensatory move-ment (Comerford & Mottram, 2001a; Mottram, 2003).Fig. 1 demonstrates relative flexibility at the lumbarspine relative to hip and knee. Other examples ofhow relatively more flexible structures compensate forrelatively stiffer structures in function include;the relatively more flexible back extensors compensatingfor relatively stiffer hip extensors producing excessive

Table 4) (reproduced with permission of Performance Stability).

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Table 5

Score sheet for test 1F demonstrating low back extension weak link

under low load (reproduced with permission of Performance Stability)

1F Single leg small knee bend+lunge & lean Results

‘Weak link’ Fail

S. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–5144

lumbar flexion (Esola, McClure, Fitzgerald, & Siegler,1996a, 1996b; Sahrmann, 2002) and relatively moreflexible scapulothoracic stabilisers compensating forrelatively stiffer scapulohumeral muscles producingexcessive scapular forward tilt or gleno-humeral transla-tion (Babyar, 1999; Mottram, 2003; Sahrmann, 2002).

A lack of ability to actively control or prevent acompensatory movement when required or instructed todo so is considered to be uncontrolled motion. Thisuncontrolled motion is defined as a ‘weak link’ or ‘give’(Comerford & Mottram, 2001b).

Load Site Direction L R

Low Low back Flexion & &

Extension � �

Rotation & &

Sidebend & &

Hip (NWB) Flexion & &

Hip (WB) Rotation (medial) & &

Lower leg (WB) Rotation (lateral) & &

2. Functional testing for uncontrolled movement—

the weak link

During functional movements muscles co-activate inintegrated patterns to control movement. Normalfunction rarely eliminates movement from one jointsystem while moving at another and rarely moves in one

Table 4

Example of a low threshold test evaluation: 1F see Fig. 3 (reproduced with

Test 1F Single leg small knee bend+lunge

Start position J Stand with one foot forward anJ Front foot is 3 foot lengths inJ Inside edge of the front foot alJ Keeping heel down, bend the kJ (the rear heel can lift)J Keep the thigh out over the secJ The back should be straight anJ The pelvis should be facing str

Test movement � Keep the spine straight (don’t

� Shift the full weight onto the fr

� Keep the pelvis facing straight

� Keep the knee and thigh over t

� Keeping the rear leg straight lif

� There should be a straight line f

� Hold the position for 5 s

Performance Matrix analysis

L R

Can you prevent rotation of the pelvis? (pelvis

staysfacing straight ahead)

Yes & No Y

Can you prevent turning in of the weight-bearing

(WB) front knee or rolling down of the arch?

Yes & No Y

Can you prevent the foot turning out or heel

pulling in? (arch rolling down 7 toe clawing)

Yes & No Y

Can you prevent the back from rounding out

(flexing)?

Yes & No Y

Can you prevent the back from over arching

(extending)?

Yes & No Y

Can you prevent sidebending of the trunk or

tilting or side shifting of the pelvis?

Yes & No Y

Can you prevent the non weight-bearing (NWB)

rear leg dropping from the straight line?

Yes & No Y

plane only. However, everybody should have the abilityto perform patterns of movement that are not habituallyused in ‘normal function’. Performance of theseunfamiliar movements is a test of control of movement

permission of Performance Stability)

& lean

d one foot back

front of rear foot (one foot length between front and rear feet)

igned straight ahead

nee to lunge forward onto the front foot

ond toe

d vertical as if sliding down a wall

aight ahead (not rotated away from the front foot)

let it round out or over arch)

ont foot by bending forward at the hips to 451 forward leaning

ahead

he second toe

t the rear toe clear of the floor

rom the point of the shoulder through the trunk and down the rear leg

Weak link

Load Site Direction

es & No Low Low back

(lumbo-pelvic)

Rotation

es & No Low Hip (WB) Rotation

(medial)

es & No Low Low back (WB)

(knee)

Rotation

(lateral)

es & No Low Low back

(lumbo-pelvic)

Flexion

es & No Low Low back

(lumbo-pelvic)

Extension

es & No Low (lumbo-pelvic) Sidebend

es & No Low Hip (NWB) Flexion

ARTICLE IN PRESS

Fig. 4. Test 7B: Elbows push up+twist to side support (see scoring

Table 6) (reproduced with permission of Performance Stability).

S. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–51 45

(Comerford & Mottram, 2003). The ability to activatemuscles to isometrically hold position or prevent motionat one segment, while concurrently actively producing amovement at another joint segment is a test of controland known as dissociation. A clinically applicablemethod of determining uncontrolled movement is basedon the concept of dissociation (Hamilton & Richardson,1998; Sahrmann, 2002; Woolsey, Sahrmann, & Dixon,1988). The subject is instructed to actively preventmovement at one joint region while concurrentlymoving at an adjacent region. For example, the subjectis instructed to prevent anterior pelvic tilt with lumbarextension while flexing the knee to 1201 against thepassive resistance of rectus femoris which attempts toanteriorly tilt the pelvis (Woolsey et al., 1988) (Fig. 1).The abdominals should be able to efficiently resist thismovement.

2.1. The weak link

The weak link may present as uncontrolled dissocia-tion movements under non-fatiguing functional move-ment or postural control load (low load) or asuncontrolled dissociation movements under high forceor high speed (high load) testing.

The site and direction of uncontrolled motion(weak link) is of particular interest to therapists as itusually relates to the direction of movement in whichpain sensitive structures are provoked by abnormalcompression or stretch. Identifying the site anddirection of uncontrolled motion may determine amechanical subgroup of movement or control dysfunc-tion and helps direct the assessment and retraining ofcontrol of movement (Comerford & Mottram, 2001b;Dankaerts, O’Sullivan, Straker et al., 2006; Sahrmann,2002).

A decrease in flexibility is not a predictor of injuryrisk (Bennell et al., 1998, 1999; Thacker, Gilchrist,Stroup, & Kimsey, 2004). Likewise, stretching does notprevent injury (Pope, Herbert, Kirwan, & Graham,1999; Thacker et al., 2004; Weldon & Hill, 2003).Muscle imbalance, lax or hypermobile movement isconsidered to be an important factor in predicting injury(Cameron, Adams, & Maher, 2003; Nadler et al., 2002;Nadler, Wu, Galski, & Feinberg, 1998; Stewart &Burdon, 2004). Since a loss of extensibility or recoveryof flexibility does not appear to be a significant factor inscreening for injury prediction or prevention it wouldseem that identifying the compensations for restrictedmotion might be more relevant. Identifying uncon-trolled movement could be a more useful component ofscreening and a priority in retraining in risk manage-ment strategies. Identifying the weak link is of value tothe sports therapist and other professionals working inthe field as it is possible to identify uncontrolledmovement before symptoms become apparent. The

correction of these faults may prevent occurrence ofpain and injury (Comerford, 2004, 2006; Comerford &Mottram, 2001b).

3. The Performance Matrix

The most significant and reliable predictor of injuryrisk in sport is a history of previous injury (Allen &Locke, 1989; Locke, 2003; Locke & Allen, 1992;Parkkari et al., 2001; Schwellnus, 2004; Watson, 2001).It seems clear then that there is a problem in the way theprevious injury is being managed. It is common (andconsidered good management) for a sports person toreturn to sport after an injury having achieved theoutcomes measures of asymptomatic function, normalrange of joint motion on isolated joint testing andnormal muscle strength on isolated muscle testing.These outcome measures are not adequate to return tosport. There must be some other factors that are notbeing measured or managed in the rehab process. Theauthors would suggest that assessing the control of ‘real’

ARTICLE IN PRESSS. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–5146

function must consider the influence of multiple muscleinteractions; multiple linked in functional movement;functionally orientated tasks and low and high thresholdloading challenges.

With increasing evidence supporting the need toidentify uncontrolled motion in multi-joint tasks as partof screening processes, an innovative new screening toolhas been developed. It has been designed to identifyaltered control strategies in terms of the site anddirection of uncontrolled movement within a chain of

Table 6

Example of a high threshold test 7B: (reproduced with permission of Perfor

Test 7B Elbows push up+twist to

Start position J Lie face down proppedJ Knees and feet togetherJ Shoulders midway betwJ Taking weight throughJ Make a straight line wit

Test movement � Keeping the pelvis neutr

onto one elbow

� As the weight shifts, tur

on with the pelvis and k

� The forearm and feet ar

� The weight bearing upp

Performance Matrix analysis

L R

Can you prevent the back from side

bending as the turn is initiated?

Yes & No Yes & No

Can you prevent the pelvis from

leading the twist? (keep the back

and pelvis turning together)

Yes & No Yes & No

Can you prevent the back from

arching?

Yes & No Yes & No

Can you prevent the pelvis and

bottom hip from dropping towards

the floor in the side position?

Yes & No Yes & No

Can you prevent the hips from

flexing? (keep the legs and trunk in

a straight line)

Yes & No Yes & No

Can you prevent the weight-bearing

(WB) shoulder blade winging?

Yes & No Yes & No

Can you prevent the weight-bearing

(WB) shoulder blade hitching?

Yes & No Yes & No

Can you prevent the weight-bearing

(WB) shoulder blade dropping?

Yes & No Yes & No

Can you prevent forward

protrusion of the head of the

weight-bearing (WB) shoulder

joint?

Yes & No Yes & No

Can you prevent the weight-bearing

(WB) forearm from turning

towards the feet (medial rotation)

as the body twists?

Yes & No Yes & No

Can you prevent the head from

turning or tilting?

Yes & No Yes & No

linked joints. It has also been designed to assess thethreshold of deficit. This tool, the ‘PerformanceMatrix’, also assesses multiple muscle interactions actingon multiple joints in functionally orientated tasks(Comerford, 2006). The key features are described inTable 1.

The Performance Matrix is a three-dimensionalassessment system to identify performance related weaklinks in the movement system. It is represented by a cubemade up of smaller blocks (Fig. 2).

mance Stability)

side support

on elbows with hands pointing to opposite elbow

een hitched and dropped

the arms, lift hips and knees off floor pushing off the toes

h legs and trunk and head

al in a straight line with the legs and trunk, shift the upper body weight

n the whole body 900 from the shoulder so that the whole body is side

nees unsupported and in a straight line with the legs and trunk

e the only contact points

er arm should be vertical

Weak link

Load Site Direction

High Low back

(lumbo-pelvic)

Sidebend

High Low back

(lumbo-pelvic)

Rotation

High Low back

(lumbo-pelvic)

Extension

High Hip (bottom leg) Adduction

High Hip Flexion

High Shoulder blade

(WB) (scapula)

Winging

High Shoulder blade

(WB) (scapula)

Hitch (elevation)

High Shoulder blade

(WB) (scapula)

Drop (downward

rotation/depression)

High Shoulder Joint

(gleno-humeral)

Forward glide

Low Shoulder joint

(WB) (gleno-

humeral)

Rotation (medial)

High Neck Rotation

ARTICLE IN PRESSS. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–51 47

The Performance Matrix uses 10 testing categories toidentify any weak link in the chain within multi-jointfunction. It identifies the ‘weak link’ in terms of site,direction and threshold of uncontrolled movement.There are five low threshold motor control testingcategories and five high threshold strength testingcategories. The testing categories are based on multi-joint functional tasks. Table 2 describes the lowload testing categories and illustrates the low loadfailures, i.e. weak links. Table 3 describes the highload testing categories and illustrates the high load

Fig. 5. Series of photos, motor control retraining of low threshold lumbar ext

hip below or the thoracic spine above.

Table 7

Test results demonstrating low back extension weak link under high

load (reproduced with permission of Performance Stability)

7B Elbows push up+twist to side support Results

‘Weak link’ Fail

Load Site Direction L R

High Neck Rotation & &

Shoulder blade (WB) Hitch & &

Drop & &

Winging & &

Shoulder joint (WB) Forward glide & &

Rotation (medial) & &

Low back Extension � �

Rotation & &

Sidebend & &

Hip (WB) Flexion & &

Adduction & &

failures, i.e. weak links. Each testing category hasseveral sub-tests that are functionally related toeach other. An example of a low threshold test isillustrated in Fig. 3 and Tables 4 and 5. An example of ahigh threshold test is illustrated in Fig. 4 and Tables 6and 7.

Each element of the testing system has a pass or failquestion? Can [test movement] be prevented or con-trolled during the test action: yes or no ? Yes ischecked ( ), if the control is good. This indicates thatthere is no weak link at that particular site in thatparticular direction under that particular load threshold.However, if no is checked as the test result ( ), thenthere is a weak link present for the site, direction andload tested.

3.1. Retraining the weak links

Following the Performance Matrix Assessment, aperformance profile is produced (Comerford, 2006)highlighting performance assets and weak links. Identi-fication of an individual’s Performance Assets can allowtraining programmes to be modified to ‘fast track’ orchallenge some processes and skills with less risk ofinjury. With an individual’s performance weak linksidentified, a prescriptive retraining programme can bedeveloped and implemented. This retraining programmeincludes strategies to regain control of the site anddirection of performance failure and retrain at theappropriate threshold of loading. These are priority riskfactors.

ension. The principle is to prevent lumbar extension while extending the

ARTICLE IN PRESS

Table 9

Guidelines for low threshold control of the site and direction of

uncontrolled motion

� Employ a dissociation motor control training strategy. That is,

prevent movement at the site of the weak link (e.g. lumbar

extension) while moving at an adjacent region (e.g. extend the hip)

as illustrated in Test 1F

� Non-fatiguing low load exercise

� Slow or static

� Unilateral or asymmetrical limb or trunk load

� Trunk does not move out of neutral

� Dissociate all three directions: rotation, flexion and extension

� Emphasise rotation control at trunk and girdles

� Trunk may move out of neutral with control

� Shortened range hold for postural control for girdle and trunk

muscles

� Discourage core ‘rigidity’ or bracing

S. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–5148

3.2. Core Stability

The term ‘Core Stability’ is a term used loosely todescribe stability retraining but its definition can beconfusing. The term ‘Core Stability’ is now used todescribe exercises that range from an almost impercep-tible activation of the deep abdominal muscles to liftingweights overhead while balancing on a physio ball. Theterm ‘motor control stability’ may be an appropriatenew label for low threshold stability concepts and is bestdefined as central nervous system modulation of efficientintegration and low threshold recruitment of local andglobal muscles systems. Strengthening is a term moreappropriate for high load or high speed training ofsymmetrical limb loading (traditional strengthening)and asymmetrical trunk loading (core strengthening).There are some defining differences between ‘motorcontrol stability’ and ‘strengthening’ (Table 8).

‘Core Stability’ now encompasses a large range ofexercise processes. These processes include: local musclesystem motor control, global muscle system motorcontrol, asymmetrical trunk loading or symmetricallimb loading (Comerford, 2004, 2006).

Based on the evidence to date, high thresholdretraining (traditional strengthening and core strength-ening) does not appear to correct motor controldysfunction in the local stability system (Moseley &Hodges, 2006; O’Sullivan, Twomey, & Allison, 1997;Tsao & Hodges, 2007). However, specific low thresholdtraining does appear to correct local and global motorcontrol stability dysfunction (Hides, Jull, & Richardson,2001; Jull et al., 2002; O’Sullivan, 2000; Tsao & Hodges,2007). Low load training does not appear to correcthigh threshold dysfunction or atrophy (Danneels,Vanderstraeten, Cambier, & Witvrouw, 2001). Both

Table 8

Defining differences between motor control and strengthening

Motor control Stability strengthening

Muscle specific: Training can be

biased for either a local stability

muscle role or a global stability

muscle role depending on the

cuing and facilitation used.

Muscle non-specific: During high

load resistance or endurance

overload training to the point of

fatigue all relevant synergists are

significantly activated. There is co-

contraction of the local stability

muscle system, global stabiliser and

global mobiliser muscle roles.

Recruitment specific: Because all

these exercises use low load or

functional normal loads then slow

motor units are predominately

recruited.

Recruitment non-specific: Again,

because of overload, both slow and

fast motor units are strongly

recruited.

Central nervous system modulated:

Afferent spindle input influences

CNS processes and tonic motor

output (‘software upgrade’).

Adaptation to load and demand:

Muscle hypertrophy is a response

to overload training (‘hardware

upgrade’).

the local or global muscle systems must integratetogether for efficient normal function (Comerford &Mottram, 2001b; Hodges, 2003). Both low thresholdmotor control and high threshold strength trainingare required for return to manual work or sport(Comerford, 2004, 2006).

3.3. Training guidelines

Once the weak link has been identified in terms of site,direction and load a specific exercise programme can beprescribed using guidelines to train one element ofCore Stability (Comerford, 2004, 2006). Guidelines forretraining low threshold weak links are detailed inTable 9. Guidelines for retraining high threshold weaklinks are detailed in Table 10.

Examples can be used to illustrate the application ofthese concepts and guidelines. Motor control retrainingof low threshold lumbar extension is illustrated in theseries of photos (Fig. 5). The principle is to preventlumbar extension while extending the hip below or thethoracic spine above. High threshold strength trainingof lumbo-pelvic rotation is illustrated in series of photos(Fig. 6). The principle is to prevent lumbo-pelvicrotation while creating a rotation challenge to thelumbo-pelvic region with a high load or high speedunilateral limb movement or rotation of the thorax.

4. Conclusion

A new system for screening for injury risk manage-ment or performance enhancement has been presented.This system can be used as a risk analysis system andcan be used to develop a training package wheretherapists and exercise professionals can implement thetests and identify the ‘weak links’. Therapists have manyreasons for screening (Table 11) and identifying specific

ARTICLE IN PRESSS. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–51 49

weak links in terms of site, direction and thresholdcan help with the reasoning process of addressingsome of these issues. Different individuals pass or faildifferent aspects of the testing process so that theindividual’s performance risks and assets can bedetermined. These risks and assets are used to develop

Fig. 6. Series of photos, high threshold strength training of lumbo-pelvic rota

rotation challenge to the lumbo-pelvic region with a high load or high speed

Table 10

Guidelines for high threshold control of the site and direction of

uncontrolled motion (reproduced with permission of Performance

Stability)

Symmetrical limb loading

‘traditional’ strengthening

Asymmetrical trunk loading

‘core’ strengthening

Employ a dissociation motor control training strategy. That is, prevent

movement at the site of the weak link (e.g. lumbo-pelvic rotation)

while moving at an adjacent region (e.g. rotate at the shoulder) as

illustrated in Test 7B

� Fatiguing high load exercise

� +/� speed

� Bilateral or symmetrical limb

load

� No rotation challenge

� Limb or trunk lifting in the

flexion extension plane

� Allow global mobiliser

dominance

� Encourage core ‘rigidity’ if

isometric core

� Fatiguing high load exercise

� +/� speed

� Unilateral or asymmetrical

limb or trunk load

� High load rotation challenge

� Emphasise rotation control at

trunk and girdles

� Resist rotation force at trunk

� Dissociate rotation, flexion

and extension

� Rotate trunk against

resistance

� Discourage global mobiliser

dominance

a client specific Performance Profile. With an indivi-dual’s performance assets and weak links identified, aspecific retraining programme can be developed andimplemented. This is a critical missing piece of thescreening and risk management puzzle. However,further research is needed to explore unansweredquestions, e.g. is it best to start with low load or highload retraining.

Conflict of Interest Statement: None.

tion. The principle is to prevent lumbo-pelvic rotation while creating a

unilateral limb movement or rotation of the thorax.

Table 11

Indications for screening (reproduced with permission of Performance

Stability)

� Unexplained performance deficits

� Eliminate intrinsic faults prior to coaching technique changes

� Prevention of injury risk

� Technique/fault correction that is resistant to coaching correction

and advice

� Pain associated with performance

� Assess for performance assets and weak links in multi-joint tasks

Low threshold tests may identify risk of:

� Injury associated with a minor incident or unguarded movements

� Overuse injury associated with repetitious low load activity or

static positioning

� Injury recurrence

� Inconsistency in repetitive performance tasks

High threshold tests may identify risk of:

� Injury associated with fatiguing loads

� Overuse injury associated with repeated high load activity

� Loss of power/consistency with high load or high speed

performance

ARTICLE IN PRESSS. Mottram, M. Comerford / Physical Therapy in Sport 9 (2008) 40–5150

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