Walking with a Passive Hip Exoskeleton and Wearables: Gait Characteristics and Metabolic Power in Senior Adults

Background: This study explored the potential of a passive exoskeleton (Exo) to improve cadence, step length, oxygen uptake, and reduce metabolic power in senior adults, with the expectation that slow walkers (SW < 0.56 m/s) would benefit more than intermediate walkers (IW ≥ 0.56 m/s). Methods: Twenty-three senior adults walked on a treadmill at their self-selected speed using the Exo, noExo, and a placebo (Sham) in a randomized and balanced order. A lower back inertial measurement unit, a heart rate monitor, and an oxygen uptake system were used to monitor spatiotemporal and cardiopulmonary parameters. Cadence, step length, heart rate, oxygen uptake (VO₂ and relative VO₂), metabolic power, and respiratory exchange ratio were extracted. A two-way MANOVA was performed across Exo vs. noExo vs. Sham and SW vs. IW. Results: Using Exo did not show any significant changes in spatiotemporal or cardiopulmonary outcomes compared to the conditions for both SW and IW. IW vs. SW seniors had significantly higher cadence (15-19%), step length (31-41%), relative VO₂ (21-23%), and metabolic power (21-23%) in all devices (p < 0.05). Conclusions: These findings show that the use of Exo among senior adults does not improve spatiotemporal parameters nor reduce metabolic powers even among SW.