Immediate Effect of an Over-Ground Walking Assistance Robot with Mecanum Wheels on Lower Limb Muscle Activity and Gait Ability in Stroke: A Single-Session Study

Background Over-ground walking assistance robots are increasingly being used in stroke rehabilitation; however, their clinical effects remain underexplored. Objective We investigated the immediate effects, in a single-session design, of an over-ground walking assistance robot with Mecanum wheels (OWAR-MW) on gait and lower limb muscle activity in stroke. Methods Thirty patients with stroke (age: 67.3 years; time since stroke: 12.4 months) participated in a repeated-measures study. Each performed a 20 m straight-line walk using Andago ® and OWAR-MW in random order. Gait was measured using a triaxial accelerometer, and surface electromyography recorded muscle activities of the rectus femoris, biceps femoris, tibialis anterior, gastrocnemius, and gluteus medius on the paretic side. Results No significant differences in gait were observed between robots (all p > .05). However, the OWAR-MW elicited greater muscle activation than the Andago ® . In particular, the gluteus medius (stance: 274.06 vs. 213.00%RVC, p = .048, d = −0.38, 95% CI [−0.745, −0.004]; swing: 354.04 vs. 199.32%RVC, p = .002, d = −0.64, 95% CI [−1.026, −0.239]) and tibialis anterior (stance: 594.23 vs. 423.70%RVC, p = .046, d = −0.38, 95% CI [−0.749, −0.007]; swing: 657.60 vs. 440.94%RVC, p = .027, d = −0.43, 95% CI [−0.796, −0.048]) showed significantly higher activation. Conclusions The OWAR-MW provided mobility assistance comparable to the Andago ® , while promoting greater lower limb muscle activation. However, these findings represent single-session physiological responses and should be interpreted as exploratory. Further research involving multi-session training and long-term functional outcomes is required to determine the clinical applicability.