Prosthetic gait deviations (TT)

What are potential causes of prosthetic gait deviations

-improper fit

-mal-alignment

-painful residual limb

-inadequate training

-motor memory/habitual pattern

What are potential consequences of prosthetic gait deviations

-increased energy consumption

-MSK injury

-limited functional outcomes

During what phase will you see TT excessive knee ext

-IC to MSt

What constitutes excessive knee ex (TT)

-<8-10 degrees of knee flexion

What view is best to assess excessive knee ext (TT)

-lateral view

What might a pt say or feel if they have excessive knee ext (TT)

-feel like I'm walking uphill

-anterior distal RL pain

-pelvic displacement (may look like PL is too long)

What are potential causes of excessive knee ext (TT)

-posterior displacement of socket/too long of a toe lever arm (ant. pylon)

-GRF moves anterior to knee axis from IC to FF

-insufficient socket flexion (want 5-8 degrees)

-heel support is too soft (too fast PF)

-inadequate training and lack of quad strength or confidence in knee control

What happens with posterior displacement of a socket/too long of a toe lever arm

-GRFV moves ant to knee axis from IC to FF (foot flat)

What is the desired socket flexion alignment

-5-8 degrees

If heel support is too soft what happens

-prosthetic foot PF too fast and creates knee ext

-most common in SACH

During what phase will you see TT knee instability

-IC to TSt

What view is best to assess knee instability (TT)

-lateral

How does knee instability often present

-A-P wobble at IC or TSt

What might a pt say or feel if they have knee instability

-I'm afraid my knee will buckle

-It won't hold me

-shortened stance phase

What are potential causes of knee instability (TT)

-toe lever arm is too short (ant socket/post pylon)

-too much DF or too much socket flexion

Why might a short toe lever arm cause knee instability

-they don't have enough room to transfer fwd --> knee flexion

During what phase will you see TT vaulting or leaning

-MSt and MSw

What view is best to assess vaulting or leaning (TT)

-from behind

Vaulting on the IL during stance phase means

-prosthetic limb is too long

Circumduction during prosthetic limb swing means

-prosthetic limb is too long

Excessive knee flexion during swing phase means

-the prosthetic is too long

What may be observed if someone vaults or leans

-excessive lateral shift (lumbar sidebending) toward PL

-vaulting on PL

What might a pt say if they are leaning

-I am walking in a hole

What might a pt say if they are vaulting

-I am walking uphill

What are potential causes of vaulting or leaning

-prosthesis is too long

-prosthesis is too short

-long toe lever arm

During what phase will you see TT drop off

-TSt

What may be observed with drop off (TT)

-knee appears to buckle in TSt

-downward mvmt of trunk in TSt

What are potential causes of drop off (TT)

-short toe lever arm

-heel is too high

T/F drop off can cause hip and back pain due to compensation

-T

During what phase will you see TT excessive valgus

-TSt

What view is best to assess excessive valgus (TT)

-AP view

What may be observed with excessive valgus (TT)

-slight medial shift of knee at TSt

What causes medial shift of knee at TSt

-excessive pressure on head of fibula and distal tibia

What are potential causes of excessive valgus

-inadequate medial offset of foot

-foot inversion

-MCL insufficiency

How do you confirm the cause of excessive valgus

-test for ligament laxity