What does an abduction gait result from?
- weak hip extensors
- prosthesis too long
- pain
How would an abduction gait result from weak hip extensors?
- amputee worries about the knee going into flexion
- might not get straight again and the amputee doesn’t have the extension strength to make it straight
- COMPENSATE by keeping it straight throughout the entire gait cycle
abduction gait: pain
pressure on the pubic ramus (crotch)
An abduction gait makes this activity difficult
ascending/descending stairs
How is a circumduction gait different from an abduction gait?
foot returns to normal position on supporting surface in stance
circumduction gait: How might the prosthesis cause this?
- overly stable knee
- prosthesis too long
circumduction gait: How might friction affect this?
increased resistance makes it hard to bend the knee for swing
Function of resistance in the prosthetic knee
helps slow the knee down from extending too quickly
What types of pts often exhibit vaulting?
those with poor trunk control
Vaulting: How might the prosthesis cause this?
- functionally longer leg during swing (due to pistoning)
- excessive friction resists knee flexion
- extension aid that’s too strong
What are the gait deviations we talked about?
- abduction gait
- circumduction gait
- vaulting
- rotation of prosthetic foot
- terminal extension
- knee instability
- whips
- foot slap
- long prosthetic step
- pimp walk
- unequal step length
What anatomical problem causes rotation of the prosthetic foot?
lack of control of the RL
What prosthetic problem causes rotation of the prosthetic foot?
- vigorous extension
- loose socket
rotation of prosthetic foot: How could this be caused by vigorous extension
- pt scared they can’t extend the leg
- overcontract glute max
- forces prosthesis into ER
What are we concerned about (in the socket) with rotation?
skin breakdown from rotational forces
What causes the terminal extension gait deviation?
- extension aid too strong
- not enough friction
- audible cues
(not mutually exclusive)
Why would the pt want terminal extension?
- audible cue tells them the knee is extended
- might have weak glutes or unsure of their stability
- throw knee to extension
*want to discourage from doing this
What anatomical issue will cause instability of the prosthetic knee?
hip flexion contracture/deformity
What happens if the pt has a hip flexion contracture?
- socket pulled forward
- creates flexion moment at knee
- knee collapses if pt doesn’t use extensors
If the pt has a contracture when they see the prosthetist, what will be done?
- adjustment of alignment to accommodate for the deformity
- pylon moved posterior to allow knee extension with contracture
- makes gait more safe
Accommodation will be done with this amount of contracture
good for small contractures (5-10˚)
What can cause instability of the prosthetic knee related to the prosthesis?
limited “DF”
What causes limited DF?
- anterior bumper is too hard
- causes knee to buckle to move from mid-terminal stance
