discharge of the rebound

To avoid that stress of "rebound" are discharged within the knee, It  is essential to anchor all the lower limb to the machine (the thigh to the seat and the leg to the movable arm) so that this "damaging" stresses are absorbed by the mechanical organ.

This operation, however, is not possible with current leg extension because there is a further problem related to the difference in machine / knee trajectory, also highlighted by the biobliographic analysis.
 
The movable arm moves, in fact, only with a rotary motion around a fixed center while the knee, after the 30 degrees, performs a roto-translational motion. 
 
This implies that if the leg is anchored to the movable arm, it  will drag the knee on its trajectory with fixed center.


So:

with the leg anchored in extension, the latter during flexion will be removed from its root with great ligament suffering;

with the leg anchored in flexion, extension the latter during
extension will create a strong compression of the articular heads with severe
cartilages and meniscus pain

The resolution of the problem, therefore, must necessarily provide that  leg extension proposes a roto-translational movement of the movable arm, similar to those of the knee so that we can anchor the whole lower limb to the machine (the thigh to the seat  and the leg to the movable arm) without causing  removal situations between the articular heads and at the same time to discharge the  "rebound" on the machine structure.