We have developed the Knee Joint named NAL-Knee (Natural
Automatic Lock Knee) for use in trans-femoral prostheses, it enables
users to ascend and descend stairs. This knee joint is 24 cm in length,
and it weighs 1230g (Fig. 1). it has a new link (referred to as a
bouncer”) under the hydraulic cylinder of the knee joint, which can
move when the load is on the heel or toe.
Stance phase control
When ascending stairs and the load is on the toe,
the knee is stopped from
bending at any chosen angle, and when descending and the load is on the heel,
it has a yielding function. This NAL Knee mechanism enables, trans femoral
amputees to ascend stairs with a reciprocal gait by stopping knee flexion.
The first day of provisional fitting
His first step between
His NAL-Knee had the center of the bouncer link
specially brought somewhat further forward, to
facilitate yielding under heel load.
MAS socket with a silicon liner.
NAL-Knee was used as the knee joint.
Two months later
He climbs up and down.
The new trans femoral amputee in this case usedthe NAL-Knee highly functional knee joint in his leg prosthesis from the start. The knee joint had already been developed as a product, and was used under the subject’s voluntary control while maintaining stability. As a result, walking speed gradually increased, and the subject was able to gain functions such as descending stairs with alternating gait at early stages. NAL Knee was highly effective for a highly active amputee.
A trans-femoral amputee with good athletic ability could accomplish it easier when using NAL-Knee climbing with a reciprocal gait.