抄録
In this study, we developed a system to evaluate efficiency of a competition bicycle pedaling. The system analyzes the magnitude and directions of leg force. The leg force was measured by new designed biaxial load cells which were applied to between pedals and shoes. To evaluate the direction of the leg forces, positions of knee, ankle and waist were analyzed. Decompositions of leg forces to tangent and normal directions of circular locus of pedals were conducted. Evaluation method of pedal efficiency was proposed by the force decomposed.