Data processing of vertical foot forces for the clinical assessment of pathological gait.

A real need has existed for the development of simple, inexpensive, and yet functionally significant gait assessment systems that could be used in clinical practice. The paper describes a new scheme for the data processing of the output of a simple foot force measuring device previously reported by the authors. Only vertical forces exerted on the forefoot and the heel are measured continuously by the device. From these signals, the muscle moment acting on the ankle, the centre of pressure in one foot and the centre of pressure between both feet are calculated. Thus information on the muscle activities at the ankle and on the transfer of body weight in the progressional direction is derived. A brief description of the mathematical background is given first, and the clinical relevance of this method is discussed with several illustrations of preliminary results on normal and pathological subjects.