Abstract：
OBJECTIVE: Muscle, tendon, and muscle-tendon unit (MTU) stiffness as well as passive peak torque (PPT) or delayed stretching pain sensation are typical explanatory approaches for stretching adaptations. However, in literature, differences in the study inclusion, as well as applying meta-analytical models without accounting for intrastudy dependency of multiple and heteroscedasticity of data bias the current evidence. Furthermore, most of the recent analyses neglected to investigate PPT adaptations and further moderators.
METHODS: The presented review used the recommended meta-analytical calculation method to investigate the effects of stretching on stiffness as well as on passive torque parameters using subgroup analyses for stretching types, stretching duration, and supervision.
RESULTS: Chronic stretching reduced muscle stiffness ( - 0.38, p = 0.01) overall, and also for the supervised ( - 0.49, p = 0.004) and long static stretching interventions ( - 0.61, p < 0.001), while the unsupervised and short duration subgroups did not reach the level of significance (p = 0.21, 0.29). No effects were observed for tendon stiffness or for subgroups (e.g., long-stretching durations). Chronic PPT (0.55, p = 0.005) in end ROM increased. Only long-stretching durations sufficiently decreased muscle stiffness acutely. No effects could be observed for acute PPT.
CONCLUSIONS: While partially in accordance with previous literature, the results underline the relevance of long-stretching durations when inducing changes in passive properties. Only four acute PPT in end ROM studies were eligible, while a large number were excluded as they provided mathematical models and/or lacked control conditions, calling for further randomized controlled trials on acute PPT effects.
METHODS: The presented review used the recommended meta-analytical calculation method to investigate the effects of stretching on stiffness as well as on passive torque parameters using subgroup analyses for stretching types, stretching duration, and supervision.
RESULTS: Chronic stretching reduced muscle stiffness ( - 0.38, p = 0.01) overall, and also for the supervised ( - 0.49, p = 0.004) and long static stretching interventions ( - 0.61, p < 0.001), while the unsupervised and short duration subgroups did not reach the level of significance (p = 0.21, 0.29). No effects were observed for tendon stiffness or for subgroups (e.g., long-stretching durations). Chronic PPT (0.55, p = 0.005) in end ROM increased. Only long-stretching durations sufficiently decreased muscle stiffness acutely. No effects could be observed for acute PPT.
CONCLUSIONS: While partially in accordance with previous literature, the results underline the relevance of long-stretching durations when inducing changes in passive properties. Only four acute PPT in end ROM studies were eligible, while a large number were excluded as they provided mathematical models and/or lacked control conditions, calling for further randomized controlled trials on acute PPT effects.
摘要：
目标：肌肉，肌腱,肌肉肌腱单位（MTU）刚度以及被动峰值扭矩（PPT）或延迟拉伸疼痛感是拉伸适应的典型解释方法。然而,在文学中,研究纳入的差异，以及应用荟萃分析模型，而不考虑数据的多重和异方差性的内部依赖性，从而使当前证据存在偏差。此外，最近的大多数分析都忽略了对PPT适应性和进一步主持人的调查。
方法：本综述使用推荐的荟萃分析计算方法，研究拉伸对刚度以及被动扭矩参数的影响，使用拉伸类型的子组分析，拉伸持续时间,和监督。
结果：长期拉伸可降低肌肉僵硬度（-0.38，p=0.01），对于有监督的(-0.49，p=0.004)和长期静态拉伸干预(-0.61，p<0.001)，而无监督和持续时间短的亚组没有达到显著性水平(p=0.21,0.29).没有观察到肌腱刚度或亚组的影响(例如，长拉伸持续时间)。最终ROM的慢性PPT（0.55，p=0.005）增加。只有长时间的拉伸才能使肌肉僵硬度急剧降低。对于急性PPT没有观察到影响。
结论：虽然部分与以前的文献一致，结果强调了诱导被动特性变化时长拉伸持续时间的相关性。最终ROM研究中只有四个急性PPT合格，虽然大量被排除在外，因为它们提供了数学模型和/或缺乏控制条件，呼吁对急性PPT效应进行进一步的随机对照试验。
方法：本综述使用推荐的荟萃分析计算方法，研究拉伸对刚度以及被动扭矩参数的影响，使用拉伸类型的子组分析，拉伸持续时间,和监督。
结果：长期拉伸可降低肌肉僵硬度（-0.38，p=0.01），对于有监督的(-0.49，p=0.004)和长期静态拉伸干预(-0.61，p<0.001)，而无监督和持续时间短的亚组没有达到显著性水平(p=0.21,0.29).没有观察到肌腱刚度或亚组的影响(例如，长拉伸持续时间)。最终ROM的慢性PPT（0.55，p=0.005）增加。只有长时间的拉伸才能使肌肉僵硬度急剧降低。对于急性PPT没有观察到影响。
结论：虽然部分与以前的文献一致，结果强调了诱导被动特性变化时长拉伸持续时间的相关性。最终ROM研究中只有四个急性PPT合格，虽然大量被排除在外，因为它们提供了数学模型和/或缺乏控制条件，呼吁对急性PPT效应进行进一步的随机对照试验。
