A Model To Measure Supination And Pronation Of The Foot Over Different Levels Of Physiological Stress Using An In-Shoe Force Monitoring System

Abstract

The purpose of this study was to create a diagnostic model of supination and pronation of the foot using vertical ground reaction forces. A size adjustable capacitive transducer retaining 960 individual pressure cells was used to assess orthopaedic parameters of gait cyale timing and vertical ground reaction forces. A pilot sample of five males were used for this model. The subjects were exposed to six experimental conditions. These being; a) a walk, b) jog, c) walk on treadmill, and d) three levels of perceived exertion (mild, moderate and hard running). Perceived exertion was measured with the Borg (RPE) scale. All subjects were measured in the same brand of athletic shoe to control for intershoe differences. The ptonation/supination model was determined by medial/lateral force and timing measurements of the calcaneus, forefoot prominence, arch, the first and fifth metatarsal heads and the toe off (end of gait cycle). Results indicated bi-Iateral differences in the medial and lateral force measurements of the calcaneus. Timing in this area was slightly different. Medial to lateral timing pronation was evidenced in the treadmill walking and moderate running condition. As well, the loading of the first and fifth metatarsal heads as a percentage of the gait cycle did not change over the running conditions. The preliminary results of five subjects provides for limited support of a vertical ground reaction model to assess pronation and supination. Further research with techniques such as high speed photography will allow for clarification of this model.