A model to calculate the joint movements and forces in the foot

The foot is a complex structure, and thus it is difficult to analyse the joint movements in the foot. Few commercial software and models consider the foot as a simple rigid segment and are not adequate to interpret the foot kinematics and kinetics. This study aimed to develop and validate a multi-segment foot model to calculate the joint kinetic and kinematic parameters in the foot during normal gait. Twelve healthy subjects participated in this study. In the experiments, the subjects walked at their comfortable speed, and a group of 13 reflective markers and ground reaction forces for each subject were collected using Vicon^reg MX-13 motion capturing system and AMTI force plates. Validation of the model was carried out by comparing the angles measured manually and the angles calculated by the model. The results showed that the model can calculate the angles and forces at the ankle, tarsometatarsal and metatarsophalangeal joints in three-dimensional planes. The outcome from this study suggests that this model adds some new functions to the traditional models and can be applied in clinical practice and sports exercise.