Investigating biomechanical function of toes through external manipulation integrating analysis

Purpose: This study was aimed to investigate the function of toes while running through comparing bound toes by external-manipulation with natural separate toes by evaluating kinematics and plantar pressure analysis. Methods: Seven habitually barefoot male runners participated in the running test under toes binding and non-binding conditions, and Vicon and Novel insole plantar pressure measurement were conducted synchronously to collect kinematics and foot loading. Results: Ankle kinematics showed larger non-significant range of motion in the frontal plane while running with toes non-binding.The medial forefoot had a smaller force time integral, and with hallux had a larger force time integral than those of running with toes binding, with significance level p < 0.05. Conclusions: While no significance existed between bound and non-bound toes in kinematics, the medial forefoot had a smaller foot impulse and the hallux had a larger foot impulse for those with non-binding feet. This suggests that other functions such as the active gripping action of toes might be important for the efficiency of the foot windlass mechanism (the plantar fascia support), which would be beneficial for running performance improvement and foot injury prevention.