Before adjusting, flex the joint and open the front, blue cover cap (Fig. 6, item C). Upon delivery
the adjustment screw is set to level 4 of the scale (highest brake sensitivity).
Turn the adjustment screw clockwise by one turn at most in order to reduce brake sensitivity. The
patient must be sitting when making this adjustment:
Problem
Relevant especially for patients with
a high body weight: Braking effect
is too aggressive; initiation of the
swing phase is difficult.
Relevant especially for patients with
a low body weight: Braking effect
is insufficient; the joint becomes
unstable in the stance phase.
4.2.4 Adjusting the brake tolerance
CAUTION
Risk of falling after adjusting the brake tolerance. Adjusting the brake tolerance can cause
the brake to get blocked or stuck and, as a result, cause the patient to fall.
Observe the following instructions.
Upon delivery the brake tolerance is optimally adjusted.
In spite of correct alignment of the prosthesis (see Section 4.1) and correct brake setting it may
become necessary to modify the brake tolerance (see table below).
To adjust, slightly turn the tension compensation screw clockwise or counter-clockwise (Fig. 6,
item B) using 710H10=2X3 Adjustment Wrench (Fig. 1, item 2).
Problem
Flexion and extension movements
are impeded when the prosthesis is
unloaded (noticeable resistance to
movement); the brake gets stuck.
Uncomfortable, jerky flexion and
extension movements upon load
bearing
Optimum setting (as delivered) is achieved, when there is no noticeable brake play upon load bear-
ing and the pendulum movement of the prosthetic lower leg is not impeded during the swing phase.
4.2.5 Adjusting the swing phase control
The mechanical swing phase control of the 3R93 can be set to 6 levels by changing the tension
of the integrated spring extension assist using 710H10=2X3 Adjustment Wrench (Fig. 1, item 2).
Upon delivery the spring adjustment ring (Fig. 7, item A) is set to level 1.
If necessary, the spring effect can be adjusted as follows:
28 | Ottobock
Cause
Brake sensitivity is set
too high.
Brake sensitivity is set
too low.
Cause
Brake tolerance upon
load bearing is too low.
After longer use, the
brake tolerance upon
load bearing is too high.
Action
Reduce brake sensitivity: Turn
adjustment screw clockwise.
Increase brake sensitivity: Turn ad-
justment screw counter-clockwise.
(Delivery condition = level 4 = high-
est brake sensitivity. Do not turn
the screw counter-clockwise any
further!)
Action
Increase brake tolerance: Care-
fully turn the tension compensation
screw clockwise.
Reduce brake tolerance: Carefully
turn the tension compensation
screw counter-clockwise.
3R93