Compliant foams can be used to mitigate ground reaction forces. However, it is unknown how foam surfaces influence the modulation of leg muscle activity. Thus, the current study aimed to investigate how the neuromuscular system managed changes in expected loading due to various thickness of foam placed on the landing surface during a step down task. The surface electromyographic signal (sEMG) pre-activation duration and the root mean square (RMS) amplitude of tibialis anterior (TA), lateral gastrocnemius (LG), and vastus medialis (VM) of 10 active females were measured as they stepped-down with a single leg onto polyurethane foam slabs of varying thickness (0–50 mm). Pre-activation duration was not affected by the thickness of the foam padding. LG RMS amplitude was less in the foam conditions than the control (no– foam) condition, with the greatest reduction observed for the 50 mm foam condition. In some trials, the muscles remained active throughout the step-down task. In such instances, a sEMG onset time and thus a pre-activation duration could not be determined. All foam conditions significantly increased the odds of continuous muscle activity above that of the no-foam condition. The results indicate that foam surfaces may alter the modulation of muscle activity during step-down tasks.

符合要求的泡沫可用于减轻地面反作用力。然而，尚不清楚泡沫表面如何影响腿部肌肉活动的调节。因此，当前的研究旨在调查神经肌肉系统如何管理由于在下台任务期间放置在着陆表面的不同厚度的泡沫而导致的预期负荷变化。测量 10 名活跃女性的表面肌电信号 (sEMG) 预激活持续时间和胫骨前肌 (TA)、外侧腓肠肌 (LG) 和股内侧肌 (VM) 的均方根 (RMS) 幅度单腿放在不同厚度（0-50 毫米）的聚氨酯泡沫板上。预活化持续时间不受泡沫衬垫厚度的影响。泡沫条件下的 LG RMS 幅度小于对照（无泡沫）条件，在 50 毫米泡沫条件下观察到的减少最大。在一些试验中，肌肉在整个降压任务中保持活跃。在这种情况下，无法确定 sEMG 开始时间，因此无法确定预激活持续时间。所有泡沫条件都显着增加了连续肌肉活动的几率，高于无泡沫条件。结果表明，泡沫表面可能会在降压任务期间改变肌肉活动的调节。