Examination of the Influence of Lead Leg Recovery Mechanics on Slip Induced Outcomes

INTRODUCTION: Slips and falls have serious implications on one’s health. Nearly every 10 seconds, an adult is treated in the hospital for fall related issues. Further, injury and mortality rates are on the rise across all populations when slips or falls are involved. Other studies have analyzed different corrective responses. However, how the recovery response may fail during a slip that results in a fall is still unclear. PURPOSE: To examine lead leg slip recovery corrective responses between falls and recoveries following an induced slip perturbation. METHODS: One hundred participants were recruited for this study. Participant’s lower extremity gait kinematics and kinetics were collected during normal gait and an unexpected slip. The variables of interest were mean sagittal moments about the ankle, knee, and hip, during stance phase. Peak moments, and time to peak moments. The slip was classified as either a fall or a recovery. Once classified, corrective responses were examined between groups using independent t-tests. Additionally, prediction equations for slip outcome were created using a binary logistic regression model. RESULTS: After exclusions, the final analysis included 64 participants, this included 39 trials classified as recoveries, and 25 trials classified as falls. The results from the logistic regression model suggest that increased time to peak hip extension (OR = 1.006, CI: 1.00-1.01) and ankle dorsiflexion (OR = 1.005, CI: 1.00-1.01) moments increased the odds of falling. While the average ankle moment was negatively associated with falling (OR = 0.001, CI: 0.001-0.005). CONCLUSIONS: After analyzing lower extremity gait during unexpected slip perturbations the results suggest that the slipping hip’s recovery response is a key factor in preventing falls. Future work focused on slip training may benefit from targeting this primary hip response of the slipping leg in order to mitigate fall risk.