Ottobock 3R60 Gebrauchsanweisung Seite 21

4.3.2 Adjusting the knee joint during trial walking
The user will notice that the EBS joint is different from other prosthetic knees because of the
Ergonomically Balanced Stride function. With EBS, the user can walk with a natural gait, allow-
ing the knee to slightly flex during stance phase without risk of falling (Fig. 3a + 3b). He or she
must learn to avoid the typical extension of the residual limb and encourage the cushioned flexion
through compression of the elastomer bumper.
As with other polycentric joints, swing phase flexion occurs when the weight is on the ball of the
foot. Alignment, foot design, condition of the residual limb, and the amputee's activity level all
influence knee function. The pendulum effect from the weight of the foot and shin length are ad-
ditional variables. Initial dynamic alignment should begin from the base setting and the function
of the knee should be explained to the patient.
Before changing the factory settings, the following guidelines must be observed:
• For changing the degree of stance flexion, first correct the position (see Section 4.3.2.1), then
re-adjust the EBS unit (see Section 4.3.2.2).
• For swing phase, adjust flexion resistance first and then adjust extension resistance (see Sec-
tion 4.3.2.3).
The knee is factory adjusted to a basic position for initial dynamic alignment
4.3.2.1 Stance phase stability by positioning the joint (Fig. 5 + 6)
Contrary to single-axis knee joints, polycentric knee joints are stable at heel strike. In the EBS
Knee Joint, the compression of the EBS unit adds additional stance phase stability. At the factory,
the EBS unit is adjusted to provide low resistance.
Initiation of swing flexion depends on the position of the joint and thus of the location of the in-
stantaneous centre of rotation. Tipping the joint in the sagittal plane (changing the angle using
the adjustment screws) can be used to determine the location of the centre of rotation and thus
to vary the degree of stability.
Stance phase stability
too great (flexion can
only be initiated with a
great deal of effort)
Insufficient stance
phase stability
(knee joint buckles)
Any adjustments performed above the joint must be corrected by corresponding counter-adjust-
ments below the joint and on the foot, in order to maintain the position of the foot, as described
in Section 4.1.2. Afterwards, repeat static alignment optimization.
Attention!
The =KD and =ST connection systems require another way of proceeding during manu-
facture of the prosthesis. Stance phase stability and initiation of flexion depend on the
position of the lamination anchor. Later readjustment of the prosthesis in the sagittal
and frontal planes is not possible!
4.3.2.2 Adjusting the ergonomically balanced stride feature (footfall stability)
The stance flexion resistance may be adjusted by compressing the elastomer bumper with the
adjustment nut. To do this, insert 710H10=2×3 Adjustment Wrench provided with the knee into
the hole (Fig. 7):
3R60, 3R60=ST, 3R60=KD, 3R60=HD
instantaneous centre
= of rotation (ICR)
too far posterior
instantaneous centre
= of rotation (ICR)
too far anterior
Tip the joint forward
using the adjustment
screws.
Tip the joint backward
using the adjustment
screws.
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=
Fig. 5
=
Fig. 6