R-720-190 Rev.
E
English
7
4.1 Alignment
Careful attention to the alignment of the socket in relation to the Plié® 3 MPC Knee and the
prosthetic foot is essential for a successful user outcome. The prosthesis alignment should
account for the range of motion (ROM), voluntary control, and balance of individual users.
Proper alignment and user voluntary control are essential to the optimal function of the
prosthesis.
Prior to assembly of the prosthesis, the prosthetist should measure the patient
’s hip joint range
of motion (ROM) on the prosthetic side to determine if the user has a hip flexion contracture
(Figure 1
). If present, the user’s hip flexion contracture should be
accommodated by attaching
the socket to the prosthesis with an appropriate amount of flexion (Figure 2). Failure to
sufficiently accommodate a hip flexion contracture can compromise the patient
’s function
during standing and ambulation (Figures 3 and 4).
During standing, an unaccommodated hip flexion contracture may prevent the patient
from standing straight, compromising the patient
’s balance (Figure
5). Additionally, an
unaccommodated hip flexion contracture can cause excessive lumbar lordosis,
compromising the structural integrity of the patient
’s spinal column (Figure
4).
During ambulation, an unaccommodated hip flexion contracture can cause an
excessively asymmetrical gait pattern.
4.2
Bench Alignment
The Plié® 3 MPC Knee should be in a fully extended position during stance phase for level
ground ambulation. An inherently stable trochanter-knee-ankle (TKA) alignment is essential to
a successful user outcome with the Plié MPC Knee. The referenced trochanter on the lateral
socket should be placed on or up to 5mm anterior to the knee joint axis (Figure 5).
An inherently unstable trochanter-knee-ankle (TKA) alignment can cause a rapid
extension moment at the knee joint after mid stance. The non-adjustable stance
extension resistance could be insufficient to dampen the extension moment if the
user does not exert sufficient voluntary control and/or if the alignment
recommendations are not implemented.
The recommended inherently stable alignment of the Plié 3 MPC Knee may differ
from other knee joints. Consequently, if a new socket is not fabricated for use with a
Plié 3 MPC Knee, the socket attachment component may require re-lamination to the
socket to achieve the recommended alignment
4.3
Static Alignment
4.3.1
Instruct the user to stand between parallel bars.
4.3.2
With equal weight on each limb, adjust the height of the prosthesis as necessary.
4.3.3
Ensure
the trochanter-knee-ankle (TKA) alignment follows the recommendations of
inherent stability.
