Gait Deviations

asymmetric step length

• due to spending less time in stance phase on amp side

• results in shortening swing time and step length on intact side

what produces energy for knee flexion?

hip and ankle activity

• utilized in TF amp

no prosthetic mechanism is needed to produce knee flexion given

• individual can flex the hip

• ambulate fast enough to produce momentum

prosthetic gait goals

• how comfortable

• aligned properly

• user’s ability

IC/LR

stride length & controlled knee flexion

MSt

pylon position & step width

TSt

smooth progression over foot & smooth flexion of limb

PSw

pelvic, trunk, and head position

swing phase

prosthetic path

TT- early prosthetic users

• fear of falling or do not trust prosthesis

• attempt to

  • keep knee extended for as long as possible

  • spend little time on prosthesis

  • increase BOS

excessive knee extension

• IC → MST, sagittal (knee joint fully extended at IC & stays that way thru early stance phase)

• causes

  • socket aligned too far posterior/foot too far anterior

  • heel too soft

  • insufficient socket flexion

  • locking knee to prevent fall

  • weak musculature around knee (weak quads)

vaulting

• excessive PF of sound limb during MSt to clear prosthetic foot (frontal)

• causes

  • prosthesis too long

  • long toe lever arm

  • socket too far posterior

  • holding knee in extension for too long

uneven step length

• taking a long step with the prosthetic limb, step to pattern with sound limb (Sw)

• sagittal

• causes

  • insufficient gait training

  • decreased pt confidence

wide based gait

• pt ambulates w/ excessively wide BOS (MSt, frontal)

• causes

  • outset foot

  • medial leaning pylon

  • insufficient weight shift/pt fear

  • hip ABD tightness

TT- weak quads/contracture

• lack of knee extension/instability

• increased pressure on distal residual limb

• shortened stance time on prosthetic limb

knee instability - TT

• IC→ lR, knee joint appears unstable during early stance phase, sagittal

• causes

  • socket aligned too far anterior/foot too posterior

  • heel too firm

  • excessive foot DF

  • weak quads, knee flexion contracture

drop off/knee instability

• early and excessive knee flexion during TSt, sagittal

• causes

  • socket aligned too far anterior/foot too posterior

  • inappropriate foot choice

  • knee flexion contracture (early and excessive knee flexion)

TT/TF - fit issues

• fitment issues can produce a wide range of gait deviations

• some easy to fix, others require referral to prosthetist

pistoning

• Sw, IC→MSt, sagittal

• loss of suspension

• causes

  • socket too large, not enough socks

  • volume changes

hip drop

• MSt, frontal

• pelvic drop toward prosthetic side during MSt

• causes

  • prothesis too short

  • residual limb pain

what is prosthetic knee flexion a result of

active hip flexion

what is prosthetic knee extension a result of

active hip extension when foot is on the ground

TF- early prosthetic users

often have fear of falling or do not have ability to control prosthetic knee

terminal impact

• Sw→ IC, sagittal

• forceful and excessive knee extension, sometimes audible

• causes

  • inadequate knee friction

  • fear of knee giving way

  • forceful hip flexion

foot slap

• IC→ LR, sagittal

• accelerated PF at heel strike resulting in foot getting flat to floor too soon

• causes

  • PF bumper too soft

  • increased hip extension force at IC

circumduction

• Sw, frontal

• user swings leg in a circular motion laterally to advance it during swing

• causes

  • prosthesis too long

  • inadequate suspension

  • excessive knee friction

  • medial wall too high

  • fear, hip flexor weakness, hip abduction contracture

vaulting

• Sw, frontal

• excessive PF of sound limb to clear prosthetic limb

• causes

  • prosthesis too long

  • inadequate suspension

  • excessive knee friction

  • fear, hip flexor weakness

abducted/wide based gait

• MSt, frontal

• excessive hip abduction during stance leading to a wide based gait pattern

• causes

  • prosthesis too long

  • medial socket wall too high

  • lateral wall not adducted enough

  • foot/leg too far outset

  • decreased balance/trying to increase BOS, abduction contracture, lateral-distal RL pain, adductor roll

TF- weak glutes

• glute max/hip extensor weakness or hip flexion contracture

  • result in: knee instability due to inability to extend knee during stance, excessive trunk extension

• glute med/hip abductor weakness

  • result in: lateral trunk bend or trendelenburg gait pattern

knee instability - TF

• IC→ LR, sagittal

• knee giving way in early stance phase

• causes

  • knee axis too far anterior

  • socket too far posterior

  • lack of socket flexion

  • inadequate hip ext strength/ROM

  • hip flexion contracture

excessive trunk extension

• MSt, sagittal

• excessive lumbar lordosis during stance or a posterior trunk lean

• causes

  • increased socket extension, not enough flexion built into socket

  • weak hip extensors, weak abs, hip flexion contracture, very short RL

lateral trunk bend

• MSt, frontal

• excessive lateral trunk lean over prosthetic limb during stance phase

• causes

  • prosthesis too short

  • socket too abducted

  • medial socket wall too high

  • glute med weakness, pain, decreased endurance, adductor roll

Drop off

• TSt, sagittal

• sudden and excessive knee flexion during late stance phase

• causes

  • short toe lever

  • socket set too posterior to knee axis

medial whip

• Sw, frontal/transverse

• medially directed whipping motion of prosthesis

• causes

  • external rotation of knee component

  • improper alignment of knee

  • improper donning

lateral whipping

• Sw, frontal/transverse

• laterally directed whipping motion of prosthesis

• causes

  • internal rotation of knee component, improper alignment of knee bolt

  • improper donning