Self-selected movement patterns during lateral locomotion with body weight support

The purpose of this study was to investigate metabolic cost, muscle activity, and perceptual responses during lateral and forward locomotion at different BWS levels at individual's preferred speed. Twelve participants performed lateral and forward locomotion on a lower body positive pressure treadmill at 0 %BWS, 20 %BWS, and 50 %BWS conditions at mode-specific preferred speed. Oxygen uptake, muscle activity, stride frequency, rating of perceived exertion (RPE), and feeling scale were measured during the tests. Oxygen uptake was influenced by the interaction of BWS and direction (P < 0.001). Muscle activity (rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius), stride frequency, and RPE during locomotion at 50 %BWS were averages of 23.7 %, 6.8 %, and 0.8 rankings lower than that of locomotion at 20 %BWS, respectively, regardless of direction (P < 0.05). Feeling scale value during locomotion at 50 %BWS was significantly higher than that of locomotion at 20 %BWS, regardless of direction (P < 0.01). During lateral locomotion, rectus femoris muscle activity was an average of 27.2 % lower and stride frequency was an average of 23.7 % greater than that of forward locomotion, regardless of BWS (P < 0.01). Furthermore, preferred speed during lateral locomotion was an average of 49.9 % lower than that of forward locomotion, regardless of BWS (P < 0.001). However, muscle activity (biceps femoris, tibialis anterior, and gastrocnemius), RPE, and feeling scale were similar between directions, regardless of BWS (P > 0.05). Our observations suggest that individuals self-selected their locomotion speed and stride frequency and induced similar magnitude of muscle activity from the lower extremity and perceptual responses during lateral locomotion and forward locomotion, regardless of BWS.