Newbould Scott, Walker Josh, Dinsdale Alexander J, Whitehead Sarah, Nicholson Gareth
Carnegie School of Sport, Leeds Beckett University, Leeds, United Kingdom.
Leeds Rhinos Netball, Leeds, United Kingdom.
PLoS One. 2025 Jun 3;20(6):e0306587. doi: 10.1371/journal.pone.0306587. eCollection 2025.
Muscle-tendon unit (MTU) assessments can be categorised into local (e.g., tendon strain) or global (e.g., jump height) assessments. Although menstrual cycle phase may be a key consideration when implementing these assessments in female athletes, the reliability of many MTU assessments is not well defined within female populations. Therefore, the purpose of this study was to report the test-retest reliability of local and global MTU assessments during the early follicular phase of the menstrual cycle. Seventeen naturally menstruating females (age 28.5 ± 7.3 years) completed local and global MTU assessments during two testing sessions separated over 24-72 hours. Local tests included Achilles' tendon mechanical testing and isometric strength of ankle plantar flexors and knee extensors, whereas global tests included countermovement, squat, and drop jumps, and the isometric midthigh pull. Based on intraclass correlation coefficient (ICC) statistics, poor to excellent reliability was found for local measures (ICC: 0.096-0.936). Good to excellent reliability was found for all global measures (ICC: 0.788-0.985), excluding the eccentric utilisation ratio (ICC 0.738) and most rate of force development metrics (ICC: 0.635-0.912). Isometric midthigh pull peak force displayed excellent reliability (ICC: 0.966), whereas force-time metrics ranged from moderate to excellent (ICC: 0.635-0.970). Excluding rate of force development (coefficient of variation [CV]: 10.6-35.9%), global measures (CV: 1.6-12.9%) were more reproducible than local measures (CV: 3.6-64.5%). However, local metrics directly measure specific properties of the MTU, and therefore provide valuable information despite lower reproducibility. The novel data reported here provides insight into the natural variability of MTU assessments within female athletes which can be used to enhance the interpretation of other female athlete data, especially that which aims to investigate other aspects of variability, such as the menstrual cycle.
肌肉 - 肌腱单元（MTU）评估可分为局部评估（如肌腱应变）或整体评估（如跳跃高度）。尽管在女性运动员中进行这些评估时，月经周期阶段可能是一个关键考虑因素，但许多MTU评估在女性群体中的可靠性尚未得到明确界定。因此，本研究的目的是报告月经周期卵泡早期局部和整体MTU评估的重测可靠性。17名自然月经周期的女性（年龄28.5±7.3岁）在相隔24 - 72小时的两次测试中完成了局部和整体MTU评估。局部测试包括跟腱力学测试以及踝关节跖屈肌和膝关节伸肌的等长力量测试，而整体测试包括反向运动跳、深蹲跳和下落跳，以及等长大腿中部拉力测试。基于组内相关系数（ICC）统计，局部测量的可靠性从差到优（ICC：0.096 - 0.936）。所有整体测量的可靠性从良好到优（ICC：0.788 - 0.985），不包括离心利用率（ICC 0.738）和大多数力量发展指标（ICC：0.635 - 0.912）。等长大腿中部拉力峰值力显示出极好的可靠性（ICC：0.966），而力 - 时间指标从中度到优（ICC：0.635 - 0.970）。不包括力量发展速率（变异系数[CV]：10.6 - 35.9%），整体测量（CV：1.6 - 12.9%）比局部测量（CV：3.6 - 64.5%）更具可重复性。然而，局部指标直接测量MTU的特定属性，因此尽管可重复性较低，但仍提供有价值的信息。此处报告的新数据为女性运动员MTU评估的自然变异性提供了见解，可用于增强对其他女性运动员数据的解释，特别是旨在研究变异性其他方面（如月经周期）的数据。
