The evaluation of the joint quasi-stiffness during the robot-assisted gait training: a pilot study

Walking may be defined as the forward displacement of the body requiring coordination between alternate successions of the swing phase and the stance phase. In literature it is known that, looking at the relationship between external moments and relative angles at lower limb joints during human walking is a new way of analyzing the biomechanical behavior of a joint (stiffness concept). Numerous studies show that the concept of quasi-stiffness applies particularly well to major loading phases of the lower extremity joints during stance phase. This study represents the first attempt to quantify the joint quasi-stiffness during the swing phase of gait over rehabilitation sessions performed by a child with cerebral palsy with the Lokomat system. The obtained results, albeit preliminarily, demonstrate the sensitivity of this new method in evaluating the degree of resistance offered by the patient over the rehabilitation sessions.