Experimental investigation and biomechanical analysis of lower limb movements for clutch pedal operation

Lower limb movements for clutch-pedal operations were investigated and the influence of four parameters (seat height, pedal travel, pedal travel inclination, pedal resistance) was studied using a multi-adjustable experimental seat. Fifteen subjects participated in the experiment: five short females, five average height males and five tall males. A biomechanical model has been proposed to explain how pedal force direction could be controlled. The experimental observations show that the lower limb movement of clutch pedal operation is mainly guided by the geometric constraints imposed by the task and its environment, especially during the depression phase. The results support the hypothesis that movements obey the principle of minimum work and minimum discomfort. Furthermore, it seems that a functional segmentation exists between the distal joint (ankle) and the proximal joints (knee and hip), thus simplifying the control problem, which is due to the redundancy of the human body. It appears that the depression movement is controlled by proprioceptive feedback related to foot displacement and pedal force, from the fact that the deceleration duration during the depression phase increases with the pedal resistance and pedal travel. The minimum pedal resistance and pedal travel are discussed.