Professorship of Sport Equipment and Materials, TUM School of Engineering and Design, Technical University of Munich, 85748 Garching, Germany.
Institute of Sports Science, Faculty of Economics and Social Sciences, Eberhard Karls Universität Tübingen, 72074 Tübingen, Germany.
Int J Environ Res Public Health. 2023 Apr 12;20(8):5486. doi: 10.3390/ijerph20085486.
(1) Background: In alpine skiing, senior athletes and especially women have a high risk of knee injury. This may also be related to muscular fatigue (MF) of the knee-stabilizing thigh muscles. This study investigates both the evolution of muscle activity (MA) and of MF of the thighs throughout an entire skiing day. (2) Methods: = 38 female recreational skiers over 40 years of age performed four specific skiing tasks (plough turns, V-steps uphill, turns with short, and middle radii) at specific times, while freely skiing the rest of the day. Surface EMG of the thigh muscle groups (quadriceps and hamstrings) was measured using special wearables (EMG pants). Apart from standard muscle activity parameters, the EMG data were also processed in the frequency domain to calculate the mean frequency and its shift over the day as a metric of muscle fatigue. (3) Results: The EMG pants showed reliable signal quality over the entire day, with BMI not impacting this. MF increased during skiing before and for both muscle groups significantly ( < 0.006) during lunch. MF, however, was not reflected in the quadriceps-hamstrings ratio. The plough manoeuvre seems to require significantly ( < 0.003) more muscle dynamics than the three other tasks. (4) Conclusion: MF may be quantified over an entire skiing day and thus fatigue information could be given to the skier. This is of major importance for skiers at the beginner level dominantly performing plough turns. Crucial for all skiers: There is no regenerative effect of a 45-min lunch break.
(1) 背景：在高山滑雪中，资深运动员，尤其是女性，存在较高的膝关节受伤风险。这可能也与膝关节稳定的大腿肌肉的肌肉疲劳（MF）有关。本研究调查了整个滑雪日中大腿肌肉活动（MA）和 MF 的变化。(2) 方法：38 名 40 岁以上的女性休闲滑雪者在特定时间完成了四项特定的滑雪任务（犁式转弯、上坡 V 型步、短半径转弯和中半径转弯），而在其余时间则自由滑雪。使用特殊的可穿戴设备（EMG 裤）测量大腿肌肉群（股四头肌和腘绳肌）的表面肌电图。除了标准的肌肉活动参数外，EMG 数据还在频域中进行处理，以计算平均频率及其全天的变化，作为肌肉疲劳的指标。(3) 结果：EMG 裤在一整天内都显示出可靠的信号质量，而 BMI 并没有影响这一点。在午餐前和午餐期间，MF 都在增加，且对两组肌肉都有显著影响（<0.006）。然而，MF 并没有反映在股四头肌和腘绳肌的比例中。犁式转弯比其他三项任务更需要明显的（<0.003）肌肉动力学。(4) 结论：MF 可以在整个滑雪日进行量化，从而为滑雪者提供疲劳信息。这对主要进行犁式转弯的初学者滑雪者非常重要。对所有滑雪者来说：45 分钟的午休时间并没有恢复作用。
