Gait Analysis Exam 2

CP Study Guide

Define cerebral palsy

“a group of conditions with variable severity with developmental features in common”; result of brain injury/malformation during fetal or neonatal development

Describe how cerebral palsy occurs

result of brain injury/malformation during fetal or neonatal development; risk factors include preterm birth, slow growth in-utero, and inflammation shortly after birth

Describe symptoms of cerebral palsy

presentation and severity is variable, some impairments include:

• neural

• muscular

• communication

• cognitive

• abnormal skeletal development

Identify muscular vs neurological vs skeletal impairment

Muscular

• weaker muscles due to smaller diameter of muscle fibers

• fewer sarcomeres (contribute to contractures); cannot add, so originals must lengthen

• shorter muscles

• greater EC matrix = more passive stiffness

• fewer satellite cells = impaired growth

Neural

• depends on location of brain injury + developmental age

  • earlier = more severe

  • hemiplegia = unilateral impairment, brain bleed in one hemisphere

  • ataxia = coordination impairment, generally cerebellar injury/malformation

• motor development impaired

• selective motor control

  • mirrored movements, involuntary movements, activation when there should not be

• inability to initiate specific movements

• spasticity

• dystonia

Skeletal

• bones do not remodel properly as a child ages bc thee is non-typical muscle actions and loading

  • acetabulum depth/orientation not formed for ‘proper’ walking

  • long bones do not grow orientated w/ gravity

  • muscle attachment points are not developed correctly

• atypical orientation + underdeveloped joint stability

Explain the difference in GMFCS levels

I: independent home + community walking, stair without railing, running, jumping

II: independent home + community walking in short distances, stairs with railing, assistive devices for long distance (maybe), limited running and jumping

III: assistive device needed, stairs are a maybe, wheeled mobility for most situations in the outdoor and for long distances

IV: significant assistance (limited walking), wheelchair to get around

Describe physical therapy and surgical management strategies for CP

Identify the sociodemographic factors that affect CP prevalence in the US

• decreased risk of CP with increased maternal education, decreased “deprivation index”

• increased risk with lower family income

• non-white americans more likely to be high risk SES

• minority groups have increased chance of lower level of care, race can be a predictor

Define dystonia

• overactive/excessive muscle activity

• contractions, both sustained/intermittent

• receptive movements

• alter posture

Define spasticity

• overactive/excessive muscle activity

• contraction in response to (rapid) stretch

  • excessive stretch reflex

  • muscles can relax

• both passive (externally initiated; PT testing ROM) or active (internally initiated; walking)

• evaluated with EMG

define contracture

• permanently shortened muscles

• altered muscle growth and improper/excessive activation can cause contractures

define hemiplegia

• one half of the body

define diplegia

• symmetrical, both sides of body

describe typical gait of general pattern of sagittal hip

• starts at 30 degrees (flexion)

• comes down to -10 degrees (extension)

• range is 40 degrees

describe typical gait of knee ankle angles

describe typical stance vs swing %

stance: when the foot is in contact with the ground, it is about 60% of gait

• starts at heel strike, ends at toe off

swing: when the foot is in the air, about 40% of gait

describe typical times when major muscle groups are typically active or silent

• activity comes slightly before motion

  • in swing, dorsiflexor EMG will light up before the individual dorsiflexes to lift the toes

  • quads activate before stance so knee extensors are ready

understand stability in stance

stability is how the body maintains alignment, adjusts for balance, holds itself upright

understand clearance in swing

lowest point of swing foot and ground, the minimum amount of lift needed to clear the ground and not ‘scuff’ the floor

• need ankle dorsiflexion, knee flexion, hip flexion, pelvis alignment

understand adequate step length

heel strike of one foot and heel strike of opposite foot

• fall risk

• energy cost

understand appropriate foot pre-positioning

preparing to lift foot and preparing to place it down

• body weight shift

• heel-foot-heel lift (toe off)

• In other card

understand energy conservation

more energy is used when muscles are activated all the time;

greater than typical muscle activation

• increased energy consumption

• greater fatigue

• less endurance

Describe how energy cost during walking differs between typically developing children and children with CP. Identify reasons for this difference.

• those with CP use more energy

• overactive muscles, co-activation

• more effort required to move the same difference

• low gait efficiency - more energy used, ‘extra work’

• maintaining stability

describe the key feature of crouch gait and equinus gait

equinus:

• greater plantar flexion due to spasticity in plantar flexors (gastrocnemii - ENG has overactive gastroc)

• individuals generally land on toes in plantar flexion

explain how equinus and crouch gait affect the prerequisites of gait

Typical: late swing is for adequate step length (flexed hip, extended knee, neutral ankle)

• equinus: shorter step length

• Crouch: shorter step length

Typical: midstance is for stabilizing and conserving energy (neutral hip, extended knee, neutral ankle)

• equinus: heel off ground or knee hypertension lead to lack of stability

• Crouch: hip and knee flexion moments are large, so there is reduced energy conservation

typical:mid-late stance is to achieve foot clearance and pre-position the foot for initial contact (flexed hip, flexed knee, dorsiflexed ankle)

• equinus:plantar flexion and compensations make foot clearance more difficult and lead to inappropriate pre-positioning

• Crouch: flexion leads to shorter step length and inappropriate pre-positioning

Identify equinus, apparent equinus, and crouch gait given sagittal plane kinematic curves

Match the appropriate clinical management to common CP gait patterns

Explain the rationale for choosing different treatment options: botulinum toxin injections, selective dorsal rhizotomy, muscle lengthening/tendon transfer, bony surgery/osteotomy

• PT

  • CP can lead to lower opportunity for motor learning

  • upper extremity with functional activity most effective

  • body-weight support makes lower extremity more difficult

  • exercise and strength training

• Botox

  • temporary, localized, non-invasive

• Bracing

  • support joints

  • realign joints

  • best when ROM is not significantly limited

  • can help with foot clearance when plantar flexion; also low knee and hip extension and GRF, excessive ankle motion, foot alignment

• SDR

  • with spasticity (overactive stretch response)

  • determine which ascending pathway is causing it, cut the nerve rootlet

  • permanent and needs extensive rehab

• muscle tendon lengthening/transfer

  • lengthening: cut and re-tether or fractionally lengthening

  • transfer: remove tendon from insertion, reattach proximal to joint (two-joint muscles)

  • can lead to weakness (can change gait, also hard to determine (functionally short not structurally short)

• extension osteotomy

  • modify bone so joint is brought out of flexion (does not weaken muscles)

  • cut bone and rotate it, pin it back together

Describe the potential negative consequences of performing an incorrect surgical procedure on a child with cerebral palsy (e.g., lengthening a muscle too much)

• overcorrect and push someone into a different type of gait

• sometimes there is no ‘fixing’ what was done

Describe the importance of gait analysis with PT evaluation, motion capture and EMG for treatment planning in CP

• need all the pieces to have a full understanding of what is happening and what someone needs

• without looking at everything, you could rule out the correct treatment or overlook something and make the gait worse

true equinus

• increased plantar flexion

jump knee equinus

• greater knee flexion

  • overactive hamstrings

apparent equinus gait

• toe walking but no excessive plantar flexion

  • hamstring spasticity, not plantar flexors

crouch gait

• greater than normal flexion at joints (flexion, dorsiflexion)

• can develop from equinus as child grows