5 Mark the centre of the socket proximally and distally on the lateral side. Draw a line through
both marks from socket brim to the distal end of the socket.
6 Now position the socket such that the alignment reference line passes through the proximal
centre mark. Set the socket flexion to somewhere between 3° and 5° taking the individual situ-
ation (e.g. hip flexion contractures) and the ischial tuberosity to ground distance into account.
CAUTION
Risk of falling as a result of incorrect alignment. If residual limb flexion is not taken into
account, the joint will be positioned too far to the front. This can lead to malfunction and
premature wear and cause the patient to fall.
7 Connect the socket and modular knee joint using a corresponding adapter (e.g. 4R111,
4R41, 4R55, 4R51 Socket Adapter). Use the 4R112 Sliding Adapter for alignment optimiza-
tion (Fig. 10). When using socket adapters with a 4-hole connection (e.g. 5R1=*, 5R6=*),
the 4R118 Sliding Adapter can be used for a permanent, additional posterior placement of
10 – 25 mm (Fig. 11).
4.1.2 Static alignment optimization with 743L100 L.A.S.A.R. Posture (Fig. 9)
After bench alignment of the prosthesis, static alignment using the L.A.S.A.R. Posture is carried
out. In order to ensure appropriate stability combined with easy initiation of the swing phase,
please proceed as follows:
1 To make the load line visible, the transfemoral amputee (with shoes) stands on the L.A.S.A.R.
Posture with the prosthetic side on the force plate and with the other leg on the height com-
pensation panel. The prosthetic side should be sufficiently loaded (> 35% of the body weight).
2 Now adapt the alignment by only adjusting the plantar flexion so that the load line (laser line)
is 40 mm anterior to the alignment reference point (= knee axis) (see Fig. 9).
4.1.3 Dynamic alignment optimization
Perform dynamic optimisation during trial walking. Often, the following aspects have to be ob-
served and adapted, if necessary:
• Socket flexion position by verifying step length symmetry (sagittal plane)
• Adduction position of the socket and M-L positioning of the socket adapter (frontal plane)
• Rotation position of the knee axis and outward rotation of the prosthetic foot (transversal plane)
Finally, document the fitting result using for example the "Dartfish" motion analysis software.
4.2 Adjustments and final assembly
CAUTION
Risk of pinching. When adjusting and assembling the knee joint, there is a risk of pinching in
the flexion range area of the knee joint. Do not reach into the flexion range area.
CAUTION
Risk of falling during trial walking. For safety reasons, the first steps of the prosthesis wearer
should always be taken between parallel bars.
24 | Ottobock
3R93