Inter-segment foot motion and ground reaction forces over the stance phase of walking

Objective. To compare the magnitude and patterns of motion of the rearfoot segment relative to the leg, forefoot segment relative to the rearfoot, height change in the medial longitudinal arch and ground reaction forces of normal adult males during the stance phased of walking. Background. Knowledge of normal motion of the rearfoot and forefoot segments and of the arch during stance phase is important in clinical management. Methods. Motion data were obtained from surface markers, and force data from a force plate, from the right limb of participants while walking at a self-selected pace. Results. Stance phase range of motion across sagittal, frontal and transverse planes was 12 degrees, 4 degrees and 10 degrees for the forefoot, compared to 22 degrees, 8 degrees and 10 degrees for the rearfoot. Most motion occurred at the beginning and end of stance phase when support was via only the rearfoot or forefoot, and when forces were maximal. Arch height decreased from heel contact and increased after heel rise to its maximum at toe-off. Conclusions. The extent of forefoot segment motion confirms the significance of midfoot joints to nor-Mal foot function. Between foot flat and heel rise, the forefoot pattern of motion is indicative of foot stability. Typical foot motion does not obey descriptions of triplanar motion such as 'pronation' and 'supination'.