下肢优势侧和非优势侧相同负重往返跑对青年学员平衡能力的影响

目的：本研究评定运动强度相同，不同运动量下肢优势侧和非优势侧相同负重往返跑对青年学员平衡能力产生的影响。方法：10名健康男性受试者平均年龄（20.80±2.04）岁，身高（173.99±2.87）cm。采用随机交互设计，10名受试者分别完成4次单侧负重往返跑：优势侧20 m×5、非优势侧20 m×5、优势侧20 m×10和非优势侧20 m×10，分别在运动后即刻和运动后20 min进行平衡能力测试，并记录R-R间期。结果：与安静状态相比，运动后，HR、EPOC和TRIMP值均显著增加（P<0.01），优势侧和非优势20 m×10 EPOC和TRIMP值显著大于20 m×5（P<0.01）。与安静值相比，优势侧和非优势侧20 m×5和20 m×10运动后即刻，整体、前后和左右方向摆动均显著增加（P<0.05），20 m×10优势侧和非优势侧左右方向摆动程度均显著高于20 m×5（P<0.05），但优势侧和非优势侧之间不存在显著差异（P>0.05），表现出对称性的变化；此外，恢复期20 min内均迅速回落到安静值（P>0.05）。结论：运动后即刻平衡能力受到干扰；运动量增加，左右方向损害程度增加；优势侧和非优势侧平衡能力的变化相似，可能存在交互效应。

Effect of lower-limb dominance and non-dominance shuttle runs under load carriage on the balance responses in young cadets

Objective: This test was designed to evaluate the effect of lower-limb dominance and non-dominance shuttle runs under load carriage during different exercise load at the same exercise intensity on the balance responses. Methods: Ten healthy young males were joined in this experiment, they were (20.80±2.04) years old and (173.99±2.87) cm tall. In a randomized cross-over design, they performed four times shuttle runs under unilateral load carriage:20 m×5 at dominant side, 20 m×5 at non-dominant side, 20 m×10 at dominant side, 20 m×10 at non-dominant side respectively. Balance abilities were evaluated immediately and 20 minute post-exercise respectively, and R-R interval was recorded. Results: The HR, EPOC and TRIMP for all exercise load were increased significantly after shuttle runs compared to rest (P<0.01), the EPOC and TRIMP for 20 m×10 shuttle runs were significantly higher than those for 20 m×5 shuttle runs at the dominant and non-dominant side (P<0.01). Compared to the rest, the instability indices (general, anteroposterior and mediolateral movement) for 20 m×5 and 20 m×10 shuttle runs immediately post-exercise at the dominant and non-dominant side were increased significantly (P<0.05), and the magnitude of the mediolateral movement for 20 m×10 shuttle runs was higher than that of 20 m×5 shuttle runs (P<0.05). While there were no obvious difference between the dominant and the non-dominant side (P>0.05), which showed symmetrical change. In addition, during 20 minute recovery, the balance ability for all exercise load was returned to the rest value (P>0.05). Conclusion: The shuttle runs could impair the trunk control ability immediately post-exercise, the magnitude of mediolateral movement was increased as the exercise load increased. The changes of balance responses were similar between the dominant and the non-dominant side, the dominant and the non-dominant side might show cross-effects.