Development of an advanced mechanised gait trainer, controlling movement of the centre of mass, for restoring gait in non-ambulant subjects

The study aimed at further development of a mechanised gait trainer which w ould allow non-ambulant people to practice a gait-like motion repeatedly. T o simulate normal gait, discrete stance and swing phases, lasting 60% and 4 0% of the gait cycle respectively, and the control of the movement of the c entre of mass were required. A complex gear system provided the gait-like movement of two foot plates wi th a ratio of 60% to 40% between the stance and swing phases. A controlled propulsion system adjusted its output according to patient's efforts. Two e ccenters on the central gear controlled phase-adjusted the vertical and hor izontal position of the centre of mass. The. patterns of sagittal lower limb joint kinematics and of muscle activat ion of a normal subject were similar when using the mechanised trainer and when walking on a treadmill. A non-ambulatory hemiparetic subject required little help hom one therapist on the gait trainer, while two therapists supported treadmill walking. Gai t movements on the trainer were highly symmetrical, impact-Tree, and less s pastic. The weight-bearing muscles were activated in a similar fashion duri ng both conditions. The vertical displacement of the centre of mass was bi- instead of mono-phasic during each gait cycle on the new device. In conclusion, the gait trainer allowed wheelchair-bound subjects the repet itive practice of a gait-like movement without overstraining therapists.