Action observation with motor simulation improves reactive stepping responses following strong backward balance perturbations in healthy young individuals

• Published in: Gait & posture Vol. 109; pp. 126 - 132
• Main Authors: Hagedoorn, Lotte, Ruiz Rodríguez, Aurora, van Asseldonk, Edwin, Weerdesteyn, Vivian
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.03.2024
• Subjects: Action observation with motor imagery; Action observation with motor simulation; Balance perturbations; Falls; First trial effect; Foot; Health Status; Humans; Lower Extremity; Movement - physiology; Physical Therapy Modalities; Postural Balance - physiology; Reactive stepping; Falls; Reactive stepping; Balance perturbations; Action observation with motor imagery; First trial effect; Action observation with motor simulation
• ISSN: 0966-6362; 1879-2219
• DOI: 10.1016/j.gaitpost.2024.01.023

Adequate reactive steps are critical for preventing falls following balance perturbations. Perturbation-based balance training was shown to improve reactive stepping in various clinical populations, but its delivery is labor-intensive and generally uses expensive equipment. Action observation of reactive steps with either motor imagery (AOMI) or motor simulation (AOMS) are potential alternative training modalities. We here aimed to study their effects on reactive stepping performance. Sixty healthy young subjects were subjected to forward platform translations that elicited backward reactive steps. The AOMI group (n = 20) was tested after AOMI of an actor’s reactive steps, while the AOMS group (n = 20) additionally stepped along with the actor. The control group (n = 20) was tested without any prior observation. Our primary outcome was the step quality of the first trial response, as this best represents a real-life loss-of-balance. Step quality was quantified as the leg angle with respect to the vertical at stepping-foot contact. We also studied single step success rates and reactive step quality across repeated trials. Reactive step quality was significantly better in the AOMI and AOMS groups than in the control group, which differences coincided with a twofold higher single step success rate. Reactive step quality improved upon repeated trials in all groups, yet the AOMS group needed the fewest repetitions to reach plateau performance. The present results demonstrate that both AOMI and AOMS improved first and repeated trial reactive stepping performance. These findings point at the potential applicability of these concepts for home-based reactive balance training, for instance in serious games, with overt movements (AOMS) possibly having some benefits over mental imaginations (AOMI). Whether similar beneficial effects also emerge in the target populations of balance-impaired individuals remains to be investigated. •Intervention: Action Observation with Motor Imagery or Motor Simulation (AOMI/AOMS).•We tested the effects of AOMI and AOMS on reactive stepping in young adults.•AOMI and AOMS resulted in better reactive steps in the first perturbation trial.•The better reactive step quality concurred with higher single step success rate.•Gains in reactive step quality upon repeated trials also benefited from AOMI and AOMS.