Exploration Of Preferred And Metabolically Optimal Walk-Run Transition Speeds During Gait With Body Weight Support

An individual’s gait transition speed between walking and running may be constrained by a change in environment such as through body weight support (BWS). Therefore, it is important to investigate the gait transition speed between walking and running at different BWS levels. PURPOSE: The purpose of this study was to investigate preferred transition speed (PTS) and metabolically optimal transition speed (MOTS) between walking and running at different levels of BWS. METHODS: Ten individuals (42.2 ± 17.6 years) participated in this study. Firstly, participant’s mode-specific PTS was measured for 0%BWS, 20%BWS, and 50%BWS conditions. Following the mode-specific PTS measurement, participants performed the actual gait tests. The BWS conditions consisted of 0%BWS, 20%BWS, and 50%BWS for walking and running. The speed conditions consist of walking and running at PTS, PTS ± 0.3 km/h, and PTS ± 0.6 km/h. Oxygen uptake, stride frequency (SF), and stride length (SL) were measured during the tests. Mode-specific PTS was analyzed using a one-way repeated measures analysis of variance (ANOVA) (α = 0.05). Oxygen uptake, SF, and SL were analyzed using a 2 (mode) x 3 (BWS) x 5 (speed) repeated measures ANOVA (α = 0.05). RESULTS: Mode-specific PTS was not significantly different between BWS conditions (i.e., 6.2 ± 1.0 km/h, 6.2 ± 1.1 km/h, and 5.7 ± 1.3 km/h for 0%BWS, 20%BWS, and 50%BWS conditions, respectively: P = 0.075). Oxygen uptake was influenced by the interaction of mode, BWS, and speed (P < 0.01). However, SF and SL were not influenced by the interaction of mode, BWS, and speed (P > 0.05). Oxygen uptake and SF during running were 17.1% ~ 27.6% and 12.8% ~ 19.9% greater than when walking at 0%BWS and 20%BWS conditions, respectively, across the different speeds. Additionally, SL during running was 14.3% ~ 24.2% shorter than when walking at 0%BWS and 20%BWS conditions, across the different speeds. Oxygen uptake during running at 20%BWS was 15.7% and 16.8% lower than that of 0%BWS at PTS + 0.3 km/h and PTS-0.3 km/h conditions, respectively (P < 0.0001). Furthermore, SL during running increased with increasing speed at 0%BWS and 20%BWS conditions (P < 0.0001). CONCLUSION: PTS and MOTS between walking and running may be different during gait at 0%BWS and 20%BWS. Supported by: Supported by JSPS Grant Number 20 K11336.