Gait Abnormalities of Above Knee Amputees During Late Swing Phase, Is It a Design Deficiency or Compensatory Strategy?

The paper reports on an intervention crossover study with repeated measures with two different prosthetic knees during two weeks adaptation period over the ground walking. The heel linear velocities of a transfemoral amputee (TFA) was measured to evaluate possible gait deficiency during heel-contact (HC). The result showed that during late swing phase just before the HC, amputee must have advanced preparation of the residual limb to adjust heel velocity for placement. The knee and the hip kinematics for reduction of the heel velocities during HC is paramount. The Knee flexion in late swing is essential to avoid impact during HC. Such mechanism does not exist in current prosthetic knees, therefore, heavy damping is necessary on the foot-heel to avoid impact.