Enhancing Gait Biomechanics in Persons With Stroke: The Role of Functional Electrical Stimulation on Step-To-Step Transition.

[BACKGROUND AND PURPOSE] Stroke often causes muscle weakness, reduced motor control, and gait abnormalities, such as foot drop and propulsion deficits, which impair weight transfer and walking efficiency. Traditional interventions such as ankle-foot orthoses and botulinum toxin address these impairments but often fail to activate the muscles involved in propulsion. Functional electrical stimulation (FES) has shown potential to enhance muscle activation and gait speed, but its effects on biomechanical parameters, particularly on step-to-step transitions, remain insufficiently explored.

[METHODS] A randomized crossover design included 18 individuals with stroke who walked with and without functional electrical stimulation (FES). Kinematic data and ground reaction forces (GRF) were recorded to evaluate step-to-step transitions. Outcome measures included the minimum vertical velocity (Vvmin) of the center of mass (CoM) and the force ratio (FRatio) between the back foot (Fback) and front foot (Ffront).

[RESULTS] FES significantly reduced the force ratio (FRatio) (p < 0.001), indicating improved force distribution toward the back foot. The minimum vertical velocity (Vvmin) of the center of mass (CoM) occurred earlier with FES (0.470 ± 0.032) compared with No FES (0.513 ± 0.033; p < 0.001), demonstrating enhanced control of CoM redirection during gait.

[DISCUSSION] FES applied to specific lower limb muscles improved critical biomechanical gait parameters, including enhanced force distribution and better control of the center of mass (CoM). These findings suggest that FES can optimize gait mechanics, particularly during step-to-step transitions, and improve walking efficiency in individuals with stroke. Further research is needed to assess its long-term effects and explore its integration into rehabilitation protocols.

[TRIAL REGISTRATION] The study was registered with Clinical Trials.gov (NCT06237972).