Experimental insights into muscle and joint roles in stumble recovery: A scoping review.

Introduction: A major concern, often resulting in serious injuries and loss of independence, is caused by falls due to stumbling. Previous works, investigating stumble recovery responses isolated to joint or muscle responses, lacks a comprehensive view of coordinated whole-body recovery.

Methods: A scoping review, on Web of Science, Scopus and PubMed, was conducted using keywords related to recovery from anteriorly-directed stumbles induced by physical obstruction of the swing limb during healthy human walking. Extracted data were experimental cohort, swing phase during stumble, perturbation apparatus, recovery strategies, biomechanical responses including joint kinematics, kinetics and muscle activity. A narrative synthesis was provided to summarize findings across studies.

Results: 23 of 337 identified studies met inclusion criteria. Limited focus on older adults or comparing them to young adults were found. Rigid and stationary obstacles were commonly used, while compliant/movable obstacles were rarely examined, limiting ecological validity. Recovery strategies varied by perturbation timing: foot elevation and lowering in early/mid-swing and late swing stumbles, respectively. Rare responses like delayed lowering and reaching were underexplored. Sagittal plane lower-limb kinematics were frequently reported, with often missing trunk motion, joint moments and EMG from proximal muscles.

Conclusion: This review highlights the importance of rapid and coordinated whole-body responses in stumble recovery, particularly involving the support limb and trunk. Findings suggest rehabilitation should target hip extensor strength, trunk control and support limb engagement to improve recovery. Future research should investigate underexplored strategies, trunk and upper-limb involvement and age-related adaptations to enhance intervention design.