What are prosthetic causes of excessive knee extension during IC->Mst?
- Socket aligned to far posterior or foot too far anterior
- Heel too soft
- Insufficient socket flexion
What are user causes of excessive knee extension during IC->Mst?
- Weak musculature around the knee
2. Locking knee in extension for stability because of fear
Excessive knee extension causes what type of moment at the knee?
Knee extensor moment
Where would you see skin break down with excessive knee extension?
Skin break down on anterior distal tibia from extending excessively in socket (bell clapping)
What are prosthetic causes of knee instability during IC->LR?
- Socket aligned too far anterior/foot aligned too far posterior
- Heel too firm
- Excessive foot DF
What are user causes of excessive knee extension during IC->LR?
- Weak quads
2. Knee flexion contracture
Where would you see skin break down/pressure with knee instability?
Unstable/pressure at posterior distal residual limb
Knee instability of TT gait will effect stance phase on prosthetic in what way?
Shortened during stance
Describe hip drop during Mst on prosthetic:
pelvic drop toward prosthetic side during Mst (best seen in frontal plane)
What are prosthetic causes of hip drop during Mst on prosthetic?
Prosthesis too short
What are user causes of hip drop during Mst on prosthetic?
Residual limb pain
What occurs with a narrow-based gait (lateral thrust)?
narrow BOS with lateral thrust of socket during Mst, excessive varus thrust at knee (frontal plane)
What are prosthetic causes of lateral thrust during Mst?
Foot too far inset
Laterally leaning pylon
What are user causes of lateral thrust during Mst?
Glute med weakness
Knee Ligament insufficiency
During lateral thrust during Mst where will you see increased pressure?
Proximal medial and distal lateral
What type of gait pattern might you see if there is lateral thrust during Mst?
uncompensated trendelenburg gait pattern.
What are prosthetic causes of wide based gait during Mst?
Outset foot
Medial leaning pylon
What are user causes of wide based gait during Mst?
Insufficient weight shift (swaying of trunk to ipsilateral side during stance phase bilaterally)
Hip abduction tightness
Patient fear
During wide based gait during Mst where will you see increased pressure?
increased pressures proximolaterally at the limb/socket interface
Describe drop-off/knee instability during TSt?
early and excessive knee flexion during TSt
What are prosthetic causes of drop-off/knee instability during TSt?
- Socket aligned too far anterior/foot too far posterior
2. Inappropriate foot choice
What are user causes of drop-off/knee instability during TSt?
Knee Flexion contracture (results in early and excessive knee flexion)
How will drop-off/knee instability during TSt effect step length of intact limb?
Shortened step length with intact limb (skip IC and get foot flat contact)
What is vaulting?
excessive PF of sound limb during MSt to clear prosthetic foot
(leads to fatigue in sound limb in calf)
What are prosthetic causes of vaulting during Sw of prosthetic?
- Prosthesis too long
- Long toe lever arm
- Socket too far posterior
What are user causes of vaulting during Sw of prosthetic?
Holding Knee in extension for too long
What is pistoning?
loss of suspension
prosthesis begins to slip off the residuum during swing
(can be because limb size decreases in size as day goes on)
What are prosthetic causes of pistoning during Swing phase, IC ->Mst?
Socket too large
Not enough socks
What are user causes of pistoning during Swing phase, IC ->Mst?
Volume changes
Not enough socks
Describe the change in step length with prosthesis with pistoning:
short step with prosthesis because they feel like limb will fall off
T/F Prosthesis experiencing pisotning is a fall risk.
True
Describe the uneven step length experienced during swing phase of TT prothesis:
taking a long step with the prosthetic limb, step-to pattern with sound limb
(shorter stance phase on prosthetic side)
What are user causes of uneven step length?
Insufficient gait training
Decreased patient confidence
Describe what circumduction of the prosthetic during swing phase?
patient swings leg around in an abducted position to advance it forward
What are prosthetic causes of circumduction of prosthesis during swing phase?
- Poor suspension
2. Prosthesis too long
What are user causes of circumduction of prosthesis during swing phase?
- Feeling of instability
2. Decreased knee flexion during swing