Ossur TOTAL KNEE 1900 Bedienungsanleitung Seite 9

• Hard bumpers decrease the locking moment of the Geometric Lock
and decrease stance flexion motion.
• Foot selection influences bumper selection.
c. For soft heels, choose a softer bumper.
d. For hard heels, choose a hard bumper.
Shim adjustment (Figure 7)
Adding shims changes the release point of the Geometric Lock allowing
for swing phase knee flexion. This affects knee stability and ease of
walking and sitting. The shims are thin plastic plates which are installed
underneath the bumper to adjust its height. A change in height affects
the knee's release point.
• More shims: easier release into swing flexion and decreased stance
flexion.
• Less or no shims: increased safety, increased stance flexion and
delayed release into swing flexion.
NOTE: There are two different types of shim. The thicker ones are
0.76mm thick and clear, the thinner ones are 0.38mm thick and grey. We
do not recommend using more shims than those two combined. Adding
more shims can eliminate the Geometric Lock and affect stability of the
knee during stance.
Gradually increase shim thickness until the user feels premature release
of the knee. Reduce shims until the user finds a balance between security
and release point. Please make initial adjustments inside parallel bars.
NOTE: If no shims are used, the knee will exhibit some flexion/extension
play during stance. If the patient finds this motion unacceptable, this can
be reduced by adding shims.
EXTENSION PROMOTER (Figure 7)
The extension promoter (14) reduces excessive heel rise and promotes
faster knee extension. It is set at minimum when shipped from Össur.
• Flex the knee to access the extension promoter adjustment screw.
• To reduce excessive heel rise, especially when walking fast, turn the
extension promoter adjustment screw clockwise with a large flathead
screwdriver.
EXTENSION ASSIST (Figure 10)
The extension assist is an OPTIONAL feature that helps get the knee back
to full extension. We recommend use of the extension assist only when
the amputee is unable to extend the knee to engage the geometric lock.
• Beneficial for users having difficulty achieving full extension.
• Can help during fast walking.
• Brings knee to full extension consistently.
• Places positive locking bias on Geometric Lock to enhance stability.
• Available with three different springs (yellow=regular, blue=firm,
red=extra firm).
INSTALLATION (Figure 10)
• Remove bumper cover, bumper and shims (Figure 7 & 8)
• Install spring cup (18) into hole inside 30mm tube clamp of knee (23)
• Firmly seat spring cup by gently tapping with rubber mallet
• Place ferrule (20) over cable (21)
• Place spring (19) over cable (21) and ferrule (20) (start with the yellow
spring)
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