Gait reaction reconstruction and a heel strike algorithm.

A mathematical model of gait ground loading is presented. The model allows the ground reactions produced by any particular single- or multiple-footfall pattern to be constructed, given a sufficient variety of other measured ground reactions. An algorithm which uses center of vertical pressure data only to determine the instants of successive heel strikes on a large force plate is then presented. Experiments show the high accuracy of the heel strike algorithm and show that reconstructions of the vertical component of ground reactions are typically within 3% of corresponding measured reactions. The techniques presented allow certain problems associated with small force plates and other problems associated with large force plates to be largely overcome.