LAMHESS, Université Côte d'Azur, Nice, France.
LIBM, Université Savoie Mont Blanc, Chambéry, France.
PLoS One. 2024 Feb 12;19(2):e0293417. doi: 10.1371/journal.pone.0293417. eCollection 2024.
After a unilateral muscle exercise, the performance of the non-exercised contralateral limb muscle can be also impaired. This crossover fatigue phenomenon is still debated in the literature and very few studies have investigated the influence of eccentric contractions. This study was designed to assess neuromuscular adaptations involved in the crossover fatigue of the non-exercised contralateral knee flexor muscles. Seventeen healthy young men performed a unilateral submaximal eccentric exercise of the right knee flexors until a 20% reduction in maximal voluntary isometric contraction torque was attained in the exercised limb. Before (PRE), immediately after exercise cessation (POST) and 24 hours later (POST24), neuromuscular function and perceived muscle soreness were measured in both the exercised limb and non-exercised limb. In addition, global perceived fatigue was assessed at each measurement time. At POST, significant reductions in maximal voluntary isometric contraction were observed in the exercised limb (-28.1%, p < 0.001) and in the non-exercised limb (-8.5%, p < 0.05), evidencing crossover fatigue. At POST, voluntary activation decreased in the exercised limb only (-6.0%, p < 0.001), while electrically evoked potentiated doublet torque was impaired in both the exercised limb and the non-exercised limb (-11.6%, p = 0.001). In addition, global perceived fatigue significantly increased at POST (p < 0.001). At POST24, all measured variables returned to PRE values, except for perceived muscle soreness scores exhibiting greater values than PRE (p < 0.05). A possible cumulative interaction between peripheral alterations and global perceived fatigue may account for the immediate crossover fatigue observed in the non-exercised limb.
在进行单侧肌肉运动后，未运动的对侧肢体的肌肉表现也可能受损。这种交叉疲劳现象在文献中仍存在争议，很少有研究调查过离心收缩的影响。本研究旨在评估非运动对侧膝关节屈肌交叉疲劳中涉及的神经肌肉适应。17 名健康年轻男性进行了单侧亚最大强度的离心运动，直到运动侧的最大自主等长收缩扭矩降低 20%。在运动前（PRE）、运动停止后即刻（POST）和 24 小时后（POST24），测量了运动侧和未运动侧的神经肌肉功能和肌肉酸痛感。此外，在每个测量时间评估了整体感知疲劳。在 POST 时，运动侧的最大自主等长收缩明显降低（-28.1%，p<0.001），未运动侧也降低（-8.5%，p<0.05），表明存在交叉疲劳。在 POST 时，仅运动侧的自愿激活降低（-6.0%，p<0.001），而电诱发增强的双重扭矩在运动侧和未运动侧均受损（-11.6%，p=0.001）。此外，整体感知疲劳在 POST 时显著增加（p<0.001）。在 POST24 时，除了肌肉酸痛评分表现出高于 PRE 的值（p<0.05）外，所有测量的变量均恢复到 PRE 值。外周改变和整体感知疲劳之间可能存在累积相互作用，这可能解释了未运动侧即刻出现的交叉疲劳。
