In recent years, applications using FES for healthy subjects have been reported. However, there exist individual differences in mobility when FES is used. In addition, the mobility identification experiment burdens the subject. In this paper, we examined the relationship between mobility and individual difference when FES is used. In the experiment, each six values were measured and their correlation was derived. Experimental results showed that the torque constant was unrelated to individual differences. It suggests that the extent of muscle development depends on the motility at the time of using FES.