Gait analysis by floor reaction force in double support period

Eight characteristic points in the double support period were determined by digitalization of floor reaction curves including vertical and fore-aft components. Phases, vertical forces and differentials of the characteristic points in variable step lengths and cadences were studied in normal gaits and pathological gaits of patients with hip, knee or ankle disorders. In normal gait, the order of appearance of characteristic points was constant in spite of changes in step length and cadence. In pathological gait, on the other hand, a reversed order or wide variation was observed in the appearance of characteristic points and differentials. Characteristic point Z1, the maximum of the differential of vertical force in the forelimb, was especially valuable in the study of pathological gait.