The present study investigated whether forward movement of the front extremity over the center of mass during foot touchdown contact, or backward movement of the rear extremity during foot release, affects step length elongation. Step length can be subdivided into touchdown distance (TD) and release distance (RD). The subjects were 6 healthy men. Their target walking speeds, recorded using three high speed cameras, were 1.3 m/s, 1.9 m/s, and 2.5 m/s. Step length showed a significant linear increase with increase in walking speed (r=0.74, p<0.001). TD increased as the walking speed increased from 1.3 m/s to 1.9 m/s, with a subsequent decrease after 1.9 m/s. No significant correlations were observed between step length and TD. RD demonstrated a significant positive correlation with step length (r=0.50, p<0.05) and the angles of external pelvic rotation (r=0.56, p<0.05), hip extension (r=0.61, p<0.05), and ankle plantar flexion (r=0.50, p<0.05) during foot release. These results show that backward movement of the rear extremity during foot release can cause step length elongation.