However, the experimental group showed significantly lower ΔO2 cost (–0.15±0.18 mL/kg·m), as compared with the control group (0.04±0.05 mL/kg·m) during overground walking (p=0.04) (Fig. 2B), although the ΔO2 cost was not signifi- cantly different between the two groups during treadmill walking (Fig. 2A).