The Typical EQD Management Paradigm New … ankle function 3.Somatosensory function & postural...

Section 1: Postural Control

(c) 2011 Beverly Cusick, PT, MS, COF 1

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New Paradigms in Equinus Deformity Management

Supporting SciencesBeverly Cusick, PT, MS – Progressive GaitWays

AOPA Assembly Educational Program

September 20, 2011

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1. Find shortened & stiff triceps surae.

2. Try to increase DFROM (gain/regain normal length)

3. Try to usenew length.

4. Repeat.

The Typical EQD Management Paradigm

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The Evident Rationale for this Paradigm

Ø Ankle PF is BAD!BAD!

Ø Spasticity causes EQD.

Ø Contractures cause movement disorder.

Ø Contracted muscle is too strong& must be weakenedmust be weakened to allow

the antagonist(s) to activate.

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Typical EQD Management Stream

1. Stretching (doesn’t work, actually)

2. Add BTX-A injection for “spasticity” (=paralysis)

2. Add 0o-PF AFO(s) (unimpressive data)

3. Another BTX-A injection (doesn’t “work” on deformity)

4. Add casting to BTX-A injection (no gain from BTX)

6. Give up, go to surgery & cut everythingpossible (variable outcomes, common recurrence)

7. Hope for the ROM gain to last >1 year or 28. Repeat or continue…..



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The New Paradigm: Supporting Sciences

1. Somatosensory function in postural controlacquisition & maintenance

2. Somatosensory function in & features ofdeveloping ankle function

3. Somatosensory function & postural controlin equinus deformity acquisition & resolution

4. Using ankle DFROM testing in orthotic planning & as evidence of effectiveness.

Why set the ankle with EQD in PF & limit DF?

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Section 1Infant

Development&

Postural ControlAcquisition

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Sensorimotor Development: A Complex, Interdependent, Emerging System of Operations

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Postural control allows us to maintain a posture while using our limbs.

The drive to achieve & maintain upright posture is innate.



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Redundancy in Neuromotor Systems Indicates the Importance of Postural Control (P-C)

• Somatosensory SystemPPC receptors - pressure, position, or movement

Tactile receptors - touch, pressure, & pain Reflexes - stretch & tonicCerebellum & basal ganglia

• Vestibular System• Vision

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Proprioceptors1. Muscle spindles

sense muscle stretch rate.

2. Golgi tendon organs (GTOs)sense stretching & loading forces in tendons.

3. Joint receptors sense movement in ligaments.

4. Mechano receptors sense pressure

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128 children, ages 3-16 yrs; 23 adults Sensory Organization Test (EquiTest) (computerized

posturography)

Steindl R, Ulmer H, et al 2004

P-C Sensory System Development

1. Somatosensory function developed early, & compared w/adult level at ages 3–4 years.

2. Visual function à adult level at age 15 yrs.

3. Vestibular function developed later, still notat adult level at age 15 years.

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Simplified, stable, organized, predictable,

muscle recruitment groupings that

coordinate the actions of many muscles

to serve the necessity for postural control in sitting

& standing positions.

Hadders-Algra M & Carlberg EB 2008, Latash M et al 2005, Assaiante C et al 2005,

Lee TD et al 1991

Central Pattern Generators (CPGs)



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The nervous system’s major role in controlling locomotion is coupled

to the biomechanics of limb motion.An understanding of control strategies must

also include the mechanical system. The optimization of human gaits & the actual output of CPGs may be directly related to the

biomechanics of limb loading.

Cappelini G, Ivanenko YP, Dominici N, et al 2010.

Saibene F, Minetti AE 2003; Srinivasan M, Ruina A 2006

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sets soft-tissue constraints & joint alignments that

optimize skeletal modeling & development of postural

alignment, control, & movement skills.

Full-Term Gestation

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…So…?

Infants born premature &/or hypotonic lack adequate soft tissue constraints needed for optimum spino-pelvic modeling.

Many premature infants develop diplegic CP with no imaging evidenceof brain injury.

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Level 1 (basic): Direction-specific, en bloc posturalpatterns; muscle activations on theside opposite the body sway,maintaining verticality -

a.k.a. “righting reactions.”

Postural Control CPGs - 2 Levels

de Graaf-Peters et al 2007

Head rightingPresent from very early infancy.

A feedback mechanism.



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Righting Reaction Requirement Successful execution of

righting reactions requires adequate nervous system maturation (myelination),

strength, & balanced use of neck & trunk muscles.Neck & trunk extensors

develop earlier than flexors.

Shumway-Cook A et al 2007; Hadders-Algra M, Brogren E, et al 1998

Vision contributes significantly in early infancy.

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Essential foundation for P-C, weight

shifting, & locomotion:bilateral, symmetrical,antigravity (Anti-G)

neck & trunkEXT & FLX.

Ideal Antigravity Postures at Age 4 Months

Bly L (1994)

Extension Flexion

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Walking Does Not àWalking

Walking is a product of hundreds of thousands of weight-shifting, sensori-motor experiences

with concurrent muscle strengthening & bone & joint formation

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Skull-side weight shift à lateral head & trunk righting à limb disassociation àoff-loading face-side limbs à

movement (rolling, belly crawling).

First Weight Shifts - Ages 5-7 MonthsFirst Integration of Anti-G EXT & FLX

Bly L (1994)



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Ideal Sitting Postures - 6-11 months

~ 6 months ~ 11 months~ 9 - 10 months

With interest in the environment& hundreds of hours of practice,

static position maintenance à weight shiftsà transitions into & out of sitting.

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Quadruped Activities - 7-12 months

Sagittal-plane “tuning” of FLX on EXT + interest in environment à reaching à diagonal loadingà

locomotion & positional transitions!

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Practice!

Prewalkers - 9-12 months - engage in ~1100 weight shifts per waking hour.

X 10 hours = >20,000/day!20,000/day!

Adolph KE, Avolio AM, Barrett T, et al 1998

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1 to 4 months

~12 months

LE Postural Changes in the 1st Year

Full-term LE alignment favors healthy foot development via loading lateral > medial borders.



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Frontal-plane stability• Develops earlier than

in the sagittal plane • Is the most important

factor in infant gaitdevelopment.

Yaguramaki N, Kimura T 2002

Standing Infant Bone & Joint Design Supports P-C Acquisition in the Frontal Plane

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Age ~12 months:• Whole foot is loaded,

forefoot > hindfoot• Foot length ~ 50% mature!• Big foot in front resists

forward shifting.• Calf ms. maintain vertical

tibias- tonic stretch reflexes assist.

Standing Infant Bone & Joint Design Supports P-C Acquisition in the Sagittal Plane

Heels are load-bearing.

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Standing body load info is provided by:

• Load receptors in LE extensor muscles thatact like springs à activate spindles & GTOs

• Joint mechanoreceptors

• Plantar cutaneous touch & pressure receptors

Force feedback from the loaded foot & ankle both inhibits & excites GTOs at the soleus muscle-tendon junction à regulates tibial inclination.

Dietz V, Duysens J 2000

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All somatosensory

receptors have links àparaspinals, cerebellum,

& the sensory-motor

cortex.

Source: Hoon AH et al 2009



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Sagittal Plane: Immature Anterior COM

“…vertical & lateral amplitudes of the

COM…were greater for children

< age 4 years; …the forward

amplitude …was greater for children

< age 7 years.”

Dierick F, Lefebvre C 200430

Toddlerhood: P-C & Foot Function

Foot-function parameters were studied in 10 toddlers at 1, 2, 3, 4, 6, 8, 10, 12, 16 & 20 wks after the onset of independent walking.

Improvements in balance – seen as decreased oscillations of the center of pressure (COP) –coincided with changes in foot roll-over.

No changes in load distribution through the plantar foot were noted, suggesting that

maturation of foot loading develops at a slower pace.

Hallemans A, De Clercq D et al 2006

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Load-related sensory input has a powerfulinfluence on the motor output in walking. Direct or indirect activation of extensor muscle

afferents that detect stretch & load during the extension period of walking enhances

the amplitude of the muscle activity, prolongs loaded LE extension,

& inhibits the transition to flexion.

Conway et al. 1987; Duysens & Pearson 1980; Guertin et al. 1995; Ivanenko et al. 2002; Pang & Yang

2000; Pearson et al. 1992; Whelan et al. 1995

All cited by Musselman KE, Yang JF 200732

Upright postural control requires a consistent experience - of normal weight-loading sensory input through the spine, legs, & feet - under variable conditions.



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• A weight-calibrated force plate• 48 children, ages 4 & 5 yrs - all

with vertical heels (no pronation)Mean % weight distribution on the

feet was mature:

• 61% heel• 35% forefoot• 4% midfoot ( <10%)

Foot Load Distribution & P-C

Aharonson Z, Voloshin A, et al 1980Cavanagh PR, Rodgers MM, et al 1987

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• With massed practice, visual, somatosensory, & vestibular inputs & body actions are mapped & integrated.

• Basic response patterns are fine-tuned to anticipate & adapt to task-specific conditions.

• APAs are learned, gain variability.

Postural Control Acquisition - Level 2:Anticipatory Postural Adjustments (APAs)

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Beginning in late infancy, EMG activity occurs in stabilizing muscles à300 millisecs prior toa purposeful action requiring postural control.

de Graaf-Peters et al 2007; Shumway-Cook A & Woollacott M 2007;

Schmitz et al 2002 & 1999

APAs are not Reactions

A feed forward mechanism.

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1 year

2 years3 years 5 years

Weight Shifts x >10,000 daily àPostural Control Mastery



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Summary• Postural control is essential to successful,

purposeful movement & function.• Somatosensory system function matures

to adult level by age 4 yrs.• Righting reactions (RRs) - the 1st postural control

mechanism to appear – operate to maintain verticality.

• Tuned muscle strength against gravity is needed for RRs to operate effectively.

• Massed practice produces mastery of postural control in each developmental play posture.

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Summary

• Postural alignment delivers body segment weight to loaded joints.

• Somatosensory input influences postural control & movement strategies.

• History of use influences sensorimotor cortical mapping.

• Massed practice - hundreds of hours, thousands of reps - establishes CPGs.

Favorably or not:

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...So..? How can we:

• Optimize body alignment to• Optimize weight distribution to• Optimize sensory experiences to• Optimize antigravity responses to• Optimize P-C acquisition & maintenance

as the foundation for optimum limbmovement & purposeful activities?

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Questions…?Discussion?

Section 2: Ideal Ankle Function


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Developing Ankle Function

Section 2

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Weight Load Distribution on the Foot

BIG DEAL

A really

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Vertical tibias are a normal & necessary feature of early walking.

Heels are loaded.

Mary Weck, PTCh. Mem. Hospital

Chicago

Big Feet!4

Vertical Tibias – A Developmental Phase

Triceps surae deceleration function is exaggerated.

Tibial inclination is constrained while

the toddler acquires balance in the sagittal plane.

The average mature tibial inclination in gait will be ~10o.



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Developmental Reversal of Ankle & Hip Gait Strategies

Analysis of 3D joint moments & power for gait in children & adults was undertaken to determine stabilization & movement strategies.

The pediatric strategy featured mainly ankle stabilization & hip propulsion.

The adults showed mainly hip stabilization &

ankle resistance & propulsion.

Samson W, Desroches G et al, 2009.6

New Data: Development ofAnkle & MTP Function in Gait

42 healthy children, 8 adults à 4 age groups:(2yrs, 3.5yrs, 5yrs, & adults.

Researchers obtained: Ground Reaction Force (GRF) data, Metatarsophalangeal (MTP) & ankle joint angles, moments, & powers.

Samson W, Dohin B, Desroches G, et al 2011

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RESULTS:

• MTP jt biomechanical parameters matured quicklyà similar between children (>age 2 yrs) & adults.

• Ankle jt parameters & GRFs (excluding the frontalplane) showed an adult-like pattern at age 5 yrs.

• Some ankle jt parameters, such as jt power, evolved significantly à age 3.5 yrs.

Based on these results, it appears that foot maturation during gait is fully achieved

at age 5 years.

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The 3 Mature Stance-Phase Rockers

<.2 sec. <.2 sec.>.2 sec

Pronation – Resolve – SupinationPronation



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New Walker’s Vertical Tibia + Hip Flexion Contracture:

• Keep loaded hip & knee in anti-sit alignment, building strength in hip & knee extensors.

• Gaining control over body COM progression by keeping body weight BACK.

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Rocker 1 with Foot Pronation

Gluteus maximus (anti-sitting muscle) contributes to COM elevation as Rocker 1 à Rocker 2.

Appears within 6 months of walking;

requires correct sagittal-plane weight loading, strength in

loaded hip abductors, & active (cortical) learning & practice to achieve.

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• Ankle functions as fulcrum for the entire body & loaded limb.

• Close proximity of loaded joints to the weight line minimizes musclework required to remain upright..

Rocker 2: Single-Limb Stance - Stability

Sources:

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Mature Rocker 2 à Midstance

• Brings COM to the highest region of the arc

• Stores potential energy• Feeds momentum

to the swing limb.• Swing limb is

unpronating stance foot.

Concentric hip extension & abduction generate à 35% of acceleration energy in gait.



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Elaine Owen’s Tripod at Mid-Stance

• Leg is inclined ~5o at fibula(~10o at anterior tibia)

• Body weight is aligned over a stable base, allowing swing limb to swing

• Vertical femur minimizes energy cost

• Weight line is centered between heel & toes.

Owen E 2008, 200914

Rocker 2: The Mighty Soleus Controls & decelerates tibia tilt past vertical

Perry J, Burnfield, J (2010) say gastroc assists.

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à Terminal MIDSTANCE

Milliseconds later:• Leg inclines slightly

•Femur inclines FASTER so that the

hip joint is anterior to,&

knee joint is posterior tothe body weight line.

GRF Vector thru the Foot

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This ideal load-bearing joint alignment

at late midstance uses anterior hip

& posterior knee

ligaments vs. musclesfor stability.

Terminal Stance



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Ankle PF Moment

Adapted from: Stout JL (2006) p. 173.18

Early Rocker 3Preloading

the Posterior Compartment Tissues For Propulsion

Ankle rapidlyà ~10o DF(fibula/floor angle)

on a congruent foot(i.e. no longer pronated).

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New Kinesiology of Ankle PF in Gait

Perry J, Burnfield J, 2010

à

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“Subtalar” Neutral PositionThe geometry of the foot bones & joints

when they are aligned infull congruity…

neither pronated nor supinated.The congruent foot is architecturally stable.

At terminal stance, it is ready to progress à supination with heel rise.



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Rocker 3 - Heel Rise with Supination

F = Triceps suraecontraction

Fulcrum = MTPs

D = Supinating(rigid) foot

M = body weight driven forward & onto the opposite foot at low energy cost

x 5000/day x 25,550 days (70 yrs).22

…So??

Ankle PF at propulsiongenerates

36 to 45% of the acceleration energy

in normal gait.

Robertson DGE et al 1980Winter DA 1983

Goldberg EJ, Requejo PS, Fowler EG 2011

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Adapted from: Stout JL (2006), p. 173.

Normal Ankle PF (accelerating) Power

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SummaryAnkles:• Quickly à PF ~10o in Rocker 1; quicklyà DF ~10o

à heel rise; quickly à PF ~20o through heel rise• Assist in absorbing shock forces during Rocker 1• Operate as body fulcrum from foot-flat in Rocker 1 à heel rise

Triceps surae:• Control tibial inclination rate, midstance à heel-rise• & Achilles tendon store elastic energy to release for

body acceleration at propulsionAnkle PF & DF are essential to optimum mature

gait function & efficiency. PF is used 2x DF.

Section 3: EQD-Postural Control

(c) 2011 Beverly Cusick, PT, MS 1

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Section 3Postural-Control

Problems& Equinus Deformity

Cause or Consequence?

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All aspects of the neuromusculoskeletal system

adapt to a history of usein the gravitational field.

Physiologic Adaptation

• Brain

• Bone

• Joint surfaces

• Muscle

• Ligament

• Fascia

• Blood vessels

• Nerves

• Skin

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REALLYBIG NEWS

Hoon AH, Stashinko EE, Nagae LM.

Sensory and motor deficits in children with cerebral palsy born preterm correlate

with diffusion tensor imaging abnormalities in thalamocortical pathways.

Devel Med Child Neurol. 2009. 51 (9) 697-704.

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Diffusion Tenser Imaging

DTI detects the direction & amount of water diffusion along the white matter tracts, & can reveal some

physical processes & deficits within the brain. Colors identify planes & directions of water

diffusion in 3-D.Nagae LM, Hoon AH, Jr. et al 2007



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28 children with CP:21 - Sp. Diplegia4 - Sp. Quadriplegia2 - Hemiplegia1 - Ataxic/hypotonic CP

Age range 16 mos to 13 yrs. Mean gest. age 28 wks.

All previously showed periventricular white matter injury (PVL) via MRI.

Hoon’s study group:

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Diffusion tensor imaging (DTI) revealed:

Many months to many years after birth,the white matter “injury” (i.e. dysfunction)

was more severe in the posterior thalamic radiation

(i.e. sensory) pathways than in the descending corticospinal pathways.

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Circled region: Assumed deficit in sens-motor connections.

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A subset of 19 subjects, ages 4 thru 8 yrs,was tested for touch, PPC,

strength, & spasticity.

• Posterior thalamic radiation dysfunction correlated with reduced contralateral touch threshold, PPC, & motor severity.

• Corticospinal tract status did not correlatewith motor or sensory outcome measures.

Hoon AH et al 2009

•



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Corroborating Evidence

High functioning children with diplegic & hemiplegic CP

have significant somatosensory deficits including

tactile, PPC, & kinesthetic inputs.

Wingert JR, Burton H et al 2009

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The “common knowledge” - that

diplegic CP“is a movement

disorder, caused by a static

lesion to the immature

motor cortex” -is questioned here.

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Spasticity (hyperreflexia) – if present at all –

can impede movement, butcannot cause equinus deformity.

Injury to the motor cortex / corticospinal tracts (a.k.a. upper motor neuron lesion) can cause spasticity – poorly modulated stretch & cutaneous reflexes.

(Lance JW 1980)

Injury to motor cortex is not evident in most children with diplegic CP; is likely in hemiplegicCP 2o perinatal stroke .

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Equinus Deformity (EQD) Development

• Follows a history of use (or nonuse) in a position of body &/or joint malalignment.

• Involves a recruitment or muscle activation history that alters the balance of ankle muscle force couples – PFs dominate.

• Features adaptive changes in the physiology of the involved muscles, fascia, nerves, blood vessels, & skin.



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Plantar Cutaneous Sensation

After desensitizing selected regions of the plantar foot with ice, subjects:

• Shifted weight à regions retaining sensation

• Altered muscle recruitment strategies & gait kinetics in order to access the sensory input.

Nurse MA, Nigg BM 2001

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…So…?Just persistent foot pronation draws COM forward.

• History of inadequate experience of antigravityEXT, FLX, & weight shifts in variety of postures à

• Reliance on immature antigravity posturalmechanisms favoring EXT over FLX à

• Chronic anterior COM carriage à• Off-loads the heel(s) à• Only met heads & toes provide sensationà• Known sensory input feeds the equinus pattern.

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Muscles are Servants of Purpose

• Our primary purpose is to remain upright while functioning.

• All other functions are secondary.

• If postural control is inadequate for function, muscles serve postural control.

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Inadequate Trunk Balance Defers Stability Work to the Limbs

Adam Pedro



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• Anterior COM• Excessive tibial

inclination• Constant need to

activate RRs usingdorsal muscles tomaintain upright.

• Limb muscles usedfor postural control

Common Postural Alignment & Body Weight Distribution in Children

with Diplegic & Hemiplegic CP

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Left Hemiplegia

AsymmDiplegia, L>R

Diplegia -Level III

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Please stand up….

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Surface EMG activityin resting &

passively elongating muscleseems to prevail as the

most accepted indicator of the presence of true

spasticity (hyperreflexia).



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CATCH: Computer Assisted Technique to Characterize Hypertonia

– To “quantify spasticity” in a clinic setting& in functional context

– To integrate measured joint kinematics with muscle EMG data.

Norris JA, Cabrera MN, et al 2007

Purposes:EMG data obtained in gait.

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How valid is CATCH as a

spasticity assessment tool?

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Sisson GA Jr, Weck M, Prihoda W, Vankoski S, Kelp-Lenane C, Moore C, Weyers A.

The effect on gait of an anterior placement of the whole body

center of mass. Gait Posture 1994. 2(1): 56. Poster.

Key Resource

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Did this TD child become spasticby walking with his COM displaced forward?

Sisson GA et al 1994

MEDIAL GASTROC EMG - TD CHILD



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Did this child overcome or cure spasticityby moving his COM backward?

Sisson G et al 1994

MEDIAL GASTROC - DIPLEGIC CHILD

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Summary• DTI reveals that the presence of motor cortex

injury & spasticity in diplegic CP is questionable.• Spasticity (hyperreflexia) cannot cause EQD,

& so should not be a deformity management target.

• Functional EMG assessment of gastroc muscle activity reveals use in postural control vs. spasticity.

• Sensory input in EQD is abnormal. Brain does not ‘know” (have mapping for) heel loading.

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• EQD in diplegia is at least partially related to a history of chronic activation of PFs for balance in the context of an en bloc righting reaction to anterior body COM displacement.

• Muscles used for balance are not available for movement.

• History of use generates GPGs for anterior COM displacement requiring calf muscle recruitment, & forefoot-only loading.

Summary

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Questions….? Discussion…?

Section 4: Assess Ankle DFROM

© 2011 Beverly Cusick PT, MS 1

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Section 4

Assessing & Understanding

Ankle DFROM

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All aspects of the neuromusculoskeletal system

adapt to a history of usein the gravitational field.

Physiologic Adaptation

• Brain

• Bone

• Joint surfaces

• Muscle

• Ligament

• Fascia

• Blood vessels

• Nerves

• Skin

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The elongation capability of a group

of relaxed musclefibers, CT, blood vessels, nerves,

& skin.

“Muscle” Extensibility:

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What is R1 end range?

“Functional”, “dynamic” end range, & “extension without violence.”

“Initial end range”& “Ao” with peripheral

nerve activity eliminated by

circulatory constriction.

Reimers 1974, 1992, 1993

Tardieu et al, 1987

TEN

SIO

N

MUSCLE LENGTH



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….R1 end range?

§ Lo & L1 on the passive length-tensioncurve. Lieber RL 1993

§ “First catch” end range.

§ “Resistance-1”(R1): “spasm-freeresistance.”

Maitland also assigned “Resistance–2”(R2) to the maximum end range.

Maitland DH 1977, p.345-7

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From RL Lieber (1993): R1 & RML:

At resting muscle resting muscle length (RML) on the length (RML) on the passive Lpassive L--T curve,T curve,

actin & myosinfilaments overlap for

optimumcross-fiber

linkage & tensile force generation.

Fascia has developed a resistance to passive

stretch around this RML.

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R1 Ankle DFROM is Developmental

• Nonexistent at birth à age ~30 months

• Emerges between ages 30 à 48 months

• Appears to be a physiologic adaptation to calf muscle use history – CT, Achilles tendon, & foot ligaments gaining integrity.

R1 is not evidence of spasticity.

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Epimysium, perimysium, & endomesiumare all the same fascia.

Extracellular (intramuscular) connective tissue matrix gains integrity with use history.



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Normal human muscle tone is determined by passive elongation, & reveals:

· Healthy extensibility of resting muscle,fascia, tendon, blood vessels, nerves, & skin

· A lack of obvious background motorunit activity in resting or passivelyelongating muscle. (Burke 1988)

• R1 end range occurs at optimum lengthfor function & age.

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Muscles recruited tonically, chronically, in shortened state adapt (transform) with:

• Muscle fiber atrophy (or lack of normal hypertrophy)Shortland AP et al 2001; Malaiya R et al 2007

• Extracellular (Intramuscular/perimyseal) CT proliferation Rose J, Haskell WL, et al. 1994

• Muscle belly CT length reduction Malaiya R et al 2007; Booth CM, Cortina-Borja MJ, et al 2001

• Adhesion formation between nerves & CT à less nerve mobility & extensibility

• Associated nerves, blood vessels & cutaneous tissues shorten. Castle ME et al 1979

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Muscle Transformation, continued:

Castle ME et al 1979; Ito J, Araki A, et al 1996; Handelsman JE, Glasser RA 1986; Rose J, Haskell WL et al 1994

Muscle fiber types reapportion à• increased % tonic (I) (decelerating)• reduced % phasic (II) (accelerating) fibers

Muscles serve purpose. Used like an orthosis (for tonic postural

control) they adapt to serve that purpose.

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Reduced (soft-tissue) compliance with

passive elongation.

Stiffness:

A feature of nonreflexive hypertonus(hypoextensibility) & evidence of soft-tissue transformation.

The passive curve begins at shorter length, & is steeper than normal.



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A Longstanding Myth:

“Strong” dominant/shortenedankle PF muscles

must be lengthened - by stretching –

or surgically weakened.

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• 28 children w/ hemiplegia & diplegiaexecuted maximal voluntary contractionsw/ EMG of bilateral PFs & DFs @ optimal angles in knee FLX & EXT

• 14 TD age- & weight-matched controls.

• MRIs of cross-sectional areas of soleus,posterior, & anterior compartment muscles.

Elder GC, Kirk J, Stewart G, et al 2003

Muscle Transformation & Strength

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• Mean EMG amplitude was significantlyreduced in PF & DF in both CP groups.

Elder GC, Kirk J, Stewart G, et al 2003

• CP groups showed significantly higherlevels of coactivation of antagonists

• PF & DF strength was significantly reducedvs. TD group.

• The PFs were most affected, particularlyin the group with hemiplegia.

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Dominant Triceps

Surae (TS) 2o chronic

toe-walkingwith COM forward.

Evidence of TS weakness

On the Length / Weakness RelationshipExample:



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Children w/ CP Show Generalized Weakness

§ Rose J, McGill KC. 2005. Neuromuscular activation and motor-unit firing characteristics in cerebral palsy. Dev Med Child Neurol. 47(5): 329-336.

§ Stackhouse SK, Binder-Macleod SA, Lee SC. 2005. Voluntary muscle activation, contractile properties, and fatigability in children with and without cerebral palsy.Muscle Nerve. 31(5): 594-601.

§ Damiano DL, Quinlivan J, et al. 2001. Spasticity versus strength in cerebral palsy: relationships among involuntary resistance, voluntary torque, and motor function.Eur J Neurol. 8 Suppl 5: 40-9.

§ Wiley ME, Damiano DL. 1998. Lower-extremity strength profiles in spastic cerebral palsy. Dev Med Child Neurol. 40(2): 100-107.

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• Detect the length of optimum contractile force generation (R1)

• Detect signs of soft tissue transformation

• Determine the capacity of the tissues to lengthen for optimum function.

Most movements are quick.

We assess ankle DFROM in order to:

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What are we asking about R1 ankle DFROM in knee extension?

…Where is the RML?20

R1 end range is never normal in children never normal in children <age 2.5 yrs.<age 2.5 yrs.

Quickly LIFT out the slackà R1

Detecting R1 DFROM with Knee Extended• Child lying prone on soft

pillows with a favoritemovie playing on a smallDVD player….muscles OFF

• Knee extended to 0o

• Foot joints fully congruent



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Triceps Surae Dominance

In CP, R1 end range DF:

q Grows increasingly heavy with advancing age

q Is also set by usage history

q Reveals soft tissuetransformation.

q Might contain poorly modulated stretchreflexes

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What are we asking about R2 DFROM in knee extension?

Can you enter Rocker 3 -

maximum tibial progression -

on a congruent foot?

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Lift à R1 Push à R2

Note the stiffness through the arc of motion.If initial range after R1 is easy, measure it, too.

R1à R2 DFROM-KE

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Diminished Muscle Length/ExtensibilityTells a story about existing

recruitment strategy. These muscles are used

for balance against falling forward all day long.



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If you cannot complete early Rocker 3, & you walk, where is

the joint motion occurring?

Relative flexibility:compensatory motion demands on neighboring joints relative to

limited primary joint motion.

Sahrmann SA (2002)

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Common Site(s) of Relative Flexibility

MTJMTJ

MTPsMTPs

Plantar Plantar aponeurosisaponeurosis

Posterior Posterior knee knee

capsulecapsule

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Common consequences of trading DFROM with KE

(Gastrocs & Tendo-Achilles length & extensibility)

for a 0o-PF AFO.

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Failure to account for R1 & R 2 DFROM-KEis the main source of discomfort, discontent,

functional difficulties, & skin breakdown in AFOs that stop PF at 0o.

Molds taken in sittingà gastrocs off tension.

Out the window…



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Why accommodate EQD (~R1) in an AFO& fill the space under the raised heel?

• To acknowledge ROM limitation & avoid forcingDF & creating related problems at foot & knee.

• To provide pressure input to the plantar heel pad.

• To activate joint mechanoreceptors in the hindfoot & ankle.

• To provide a “landing pad” for the hindfoot thatprotects the MTJ & posterior knee from strain.

• To facilitate neuromotor re-education to correctCOM orientation over the foot.

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Why doesn’t setting the EQD in PF and limiting DF increase EQD?

• Because the cause of EQD is postural control, not the PF’d angle. We must address the source.

• EQD increases when ankle PFs must activate for balance while in PFd position.

• EQD features altered sensory input through the foot & ankle & no knowledge of normal loading.

• Tuning AFOs & shoes is a way of serial casting, which is effective in reducing EQD for all the same reasons.

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It’s a JUNGLE out there!!!...

Ankle ROM Assessment Procedures…

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Why care about test replicability?

• Ankle DFROM reveals evidence of the existing PF muscle recruitment strategy.

– Stiffness & ROM limitations indicate chronic use for balance.

– Normal ROM indicates normal use in presence of competent postural control.

• Changes in DFROM reveal evidence of effectiveness of EQD management strategies, including weight-line training to increase heel loading.

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Goniometric Reliability – Hip & Ankle Assessments – Diplegic Children

38 children, 3 PTs, 2 sessions. Mean absolute differences for all PROM measures

between sessionsranged from 0.10 o à 4.86 o

Mutlu A, et al 2007

These “results encourage the use of goniometric measurements in assessing

children with spastic diplegic CP.”

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Factors Affecting Confidence & Relevance:• Positioning the client – why prone vs. supine? • Correcting knee hyperextension• Positioning yourself • Palpating & bisecting fibular landmarks• Aligning the foot joints in full congruity

– neither supinated nor pronated• Detecting R1 end range with foot joint congruity• Detecting R2 end range with foot joint congruity • Handling & reading a goniometer

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• Choice of reference arms- Plantar heel pad / fibula- 5th met shaft / fibula

• Manual grip on the foot

• Visual orientationto the ankle joint

See Legs & Feet DVD for detailed procedure demos.

www.gaitways.com

http://www.gaitways.com



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Cusick’s Ideal Ankle DFROM - R1 / R2

Obtained in comfortable prone position with knee at 0o & foot joints maintained

in full congruity. 38

• Ankle DFROM can be measured reliably.• R1 DF-KE indicates RML & tissue health.• R1 DF-KE is developmental & is set by usehistory maintaining standing & during Rocker 3.

• R1 DF at <30 months of age is pathological.• R2 DF-KE shows the capacity to quickly achieve

tibial progression into early Rocker 3 with thefoot joints congruent & ready to supinate.

• R2 DF to 0o is pathomechanical at all ages.• Ankle DFROM gains indicate improved postural

control & muscle recruitment strategy.

Summary

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QuestionsQuestions……? Discussion? Discussion……??

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Thank you for this honor & opportunity to speak with you.

Next, your colleagues will share their experiences working with

the new paradigm.

The Typical EQD Management Paradigm New … ankle function 3.Somatosensory function & postural...

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