Biomechanical strategies for mitigating unexpected slips: A review

Abstract

Slips are the leading cause of falls, and understanding slip biomechanics is crucial for preventing falls and mitigating their negative consequences. This study analyses human biomechanical responses to slips, including kinetic, kinematic, spatiotemporal, and EMG variables. We reviewed 41 studies investigating slip-induced falls in lab settings, computational models, and training approaches. Our analysis focused on reactions and effects of factors like age, fatigue, strength, perturbation intensity, and gait speed. Trailing limbs' hip extension and knee flexion interrupt the swing phase earlier, increasing the support base. The slipping leg responds with two phases: hip extension and knee flexion, then hip flexion and knee extension. Furthermore, our analysis revealed that the medial hamstring muscles play an active role in slip recoveries. Their activation in the slipping limb allows for hip extension and knee flexion, while in the trailing limb, their activation results in the foot touching down. Additionally, successful slip recoveries were associated with co-contraction of the Tibialis Anterior (TA) and Medial Gastrocnemius (MG), which increases ankle joint stability and facilitates foot contact with the ground. Our review identifies various factors that influence biomechanical and muscular responses to slips, including age, perturbation intensity, gait speed, muscular fatigue, and muscular strength. These findings have important implications for designing interventions to prevent slip-related falls, including cutting-edge technology devices based on a deeper understanding of slip recoveries. Future research should explore the complex interplay between biomechanics, muscle activation patterns, and environmental factors to improve slip-fall prevention strategies.

Keywords: Biomechanical response; Fall prevention; Slip-like perturbation; Target specification; Wearable robotic device.