5.1.5 Dynamic Trial Fitting
•
Adapt the alignment of the prosthesis in the frontal plane and the sagittal
plane (e.g. by making angle or slide adjustments) to ensure an optimum
gait pattern.
•
TT fittings:
Make sure that physiological knee movement in the sagittal
and frontal plane is achieved when the leg begins to bear weight after
the heel strike. Avoid medial movement of the knee joint. If the knee joint
moves in the medial direction in the first half of the stance phase, move
the prosthetic foot in the medial direction. If the medial movement occurs
in the second half of the stance phase, reduce the exterior rotation of the
prosthetic foot.
•
Remove the plastic protector from the pyramid after completing the
dynamic fitting and the walking exercises.
Heel too soft
Symptoms
Possible solutions
• Foot makes full ground contact too
quickly
• Forefoot feels too stiff
• Knee goes into hyperextension
• Shift prosthetic socket forward relative
to the foot
• Use a heel wedge
Heel too hard
Symptoms
Possible solutions
• Fast knee flexion, low stability
• Transition from heel strike to toe-off too
fast
• Energy return feels low
• Shift prosthetic socket back relative to
the foot
• Reduce the heel stiffness (shift or
remove heel wedge)
Prosthetic foot too stiff
Symptoms
Possible solutions
• Minimal rollover movement of the pros
thetic foot at low walking speed (long
full ground contact)
• Select prosthetic foot in lower stiffness
Prosthetic foot too soft
Symptoms
Possible solutions
• Clicking noise at the start of ground
contact.
• Very pronounced deformation of the
forefoot at high activity levels
• Select prosthetic foot in higher stiff
ness
5.1.5.1 Optimising the heel characteristics
The behaviour of the prosthetic foot at heel strike and during heel contact in
the mid-stance phase can be adapted with the placement of a heel wedge.
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