Effects of leg fatigue due to exhaustive stair climbing on gait biomechanics while walking up a 10˚ incline – implications for evacuation and work safety

Abstract This biomechanics study explored stride length (SL), duration (SDN), and gait ground reaction forces (GRFspeak), required coefficient of friction (RCOFpeak), joint angle (anglepeak, anglemin), angular velocities (angvelx peak), angular accelerations (angaccx peak), muscle electromyography (EMG) during the dominant leg stance phase (SP) following an exhaustive stair ascent for evacuation. Data were collected by a three-dimensional motion capture system synchronized with EMG and force plate when walking upwards on a 10° inclined walkway. The significantly (p≤0.05) decreased EMG median frequencies of tibialis anterior during early (ES) and late stance (LS) phases, and vastus lateralis muscles during LS are the evidence of leg local muscle fatigue (LMF). The perpendicular and longitudinal shear GRFspeaks were significantly reduced during ES (p≤0.05) and LS (p≤0.01), respectively. The post-fatigue SP, SL, and SDN were significantly (p