全身振动训练中站立姿势对老年人肌肉形态和功能的影响：一项随机对照试验。

BACKGROUND: Whole body vibration (WBV) is a novel modality of exercise shown to improve musculoskeletal function. This study aims to examine the effects of standing posture during low magnitude WBV training on muscle function and muscle morphology in older adults. METHODS: Nineteen men and women (50-80 years) were recruited to a three month randomised controlled trial and allocated to one of three groups: WBV with flexed knees (FK), WBV with locked knees (LK), or sham WBV with flexed knees (CON). Exposure was intermittent (1 min WBV:1 min rest) for 20 min, three times per week for 13 weeks. Measurements were taken at baseline and at three months. Primary outcomes included upper and lower body muscle function (strength, power and velocity). Secondary outcomes were muscle morphology, balance, habitual and maximal gait velocity, stair climb power, and chair stand performance. RESULTS: Sixteen subjects completed the study. Relative (%) upper body contraction velocity improved significantly after WBV with FK compared to LK (FK 16.0%, LK -7.6%, CON 4.7, p = 0.01). Relative upper body strength (LK 15.1%, p = 0.02; FK 12.1%, p = 0.04; CON 4.7%) increased significantly following WBV compared to control. Absolute (p = 0.05) and relative (p = 0.03) lower leg strength significantly improved with both standing postures (LK 14.4%; FK 10.7%; CON 1.3%). Only the LK group differed significantly from CON in relative leg strength gains (p = 0.02). Potentially clinically meaningful but statistically non-significant improvements in lower leg muscle cross-sectional area (LK 3.7 cm², FK 2.4 cm², CON 2.2 cm² p = 0.13) were observed after WBV with LK compared to the other groups. No significant effects of WBV on any functional performance tests were observed. CONCLUSIONS: Our results suggest that WBV may improve muscle strength and contraction velocity in some muscle groups in older adults. However, hypothesised differential adaptation to standing posture (FK > LK) was observed only for upper body contraction velocity, making recommendations regarding this prescriptive element inconclusive. The efficacy, mechanism of action and long term feasibility of WBV for musculoskeletal health in older adults warrants continued investigation in robustly designed, sufficiently powered future studies. TRIAL REGISTRATION: ACTRN12609000353291.

背景：全身振动（WBV）是一种新的运动方式，已被证明可以改善骨骼肌肉功能。本研究旨在探讨在低幅度 WBV 训练中采用不同站立姿势对老年人肌肉功能和形态的影响。

方法：19 名年龄在 50-80 岁的男性和女性被招募参加为期三个月的随机对照试验，并分为三组：屈膝位 WBV（FK）、锁膝位 WBV（LK）和屈膝位假 WBV（CON）。暴露时间为间歇性（1 分钟 WBV：1 分钟休息），每周 3 次，共 13 周。在基线和 3 个月时进行测量。主要结局包括上下肢肌肉功能（力量、功率和速度）。次要结局包括肌肉形态、平衡、习惯性和最大步行速度、爬楼梯功率和坐站表现。

结果：16 名受试者完成了研究。与 LK 相比，FK 组的上半身收缩速度相对（%）明显提高（FK 16.0%，LK -7.6%，CON 4.7%，p=0.01）。与对照组相比，上半身力量相对增加（LK 15.1%，p=0.02；FK 12.1%，p=0.04；CON 4.7%）。两种站立姿势（LK 14.4%；FK 10.7%；CON 1.3%）绝对（p=0.05）和相对（p=0.03）小腿力量均显著提高。仅 LK 组与 CON 组在相对腿部力量增加方面存在显著差异（p=0.02）。与 LK 相比，LW 组的小腿肌肉横截面积有潜在的临床意义但统计学上无显著改善（LK 3.7 cm²，FK 2.4 cm²，CON 2.2 cm²，p=0.13）。

结论：我们的结果表明，WBV 可能会改善老年人某些肌肉群的肌肉力量和收缩速度。然而，只有上半身收缩速度观察到对站立姿势（FK> LK）的假设差异适应，这使得关于这种规定性因素的建议没有定论。在设计严谨、足够有力的未来研究中，需要继续研究 WBV 对老年人骨骼肌肉健康的疗效、作用机制和长期可行性。

试验注册：ACTRN12609000353291。