DosʼSantos Thomas, Thomas Christopher, Jones Paul A, McMahon John J, Comfort Paul
Human Performance Laboratory, Directorate of Sport, Exercise, and Physiotherapy, University of Salford, Greater Manchester, United Kingdom.
J Strength Cond Res. 2017 Oct;31(10):2748-2757. doi: 10.1519/JSC.0000000000002098.
The aim of this study were to compare isometric midthigh pull (IMTP) peak force (PF), time-specific force values (100-, 150-, and 200 ms), rate of force development (RFD) at predetermined time bands (0-100, 0-150, and 0-200 ms) and net forces between 2 commonly adopted hip joint angles (145°[hip145] and 175°[hip175]) with a 145° standardized knee angle. Twenty-eight collegiate athletes (age: 21.7 ± 1.5 years, height: 1.75 ± 0.08 m, mass: 81.5 ± 8.4 kg) performed 2 IMTP trials at each hip joint angle in a randomized counterbalanced order. A subgroup (n = 10) performed the IMTP testing 7 days later to establish the between-session reliability. Intraclass correlation coefficients (ICCs) and coefficient of variation (CV) demonstrated high within-session reliability and acceptable variability for all IMTP kinetics at each posture (ICC ≥ 0.86, CV ≤ 13.7%), excluding hip175 RFD 0-100 ms and net force at 100 ms which demonstrated greater variability (CV = 18.1-18.5%). High between-session reliability and acceptable variability were observed for all IMTP kinetics at each posture (ICC = 0.72-0.97, CV = 4.5-12.8%), excluding RFD 0-100 ms which demonstrated greater variability for both postures. Hip145 produced significantly greater time-specific force values (p ≤ 0.025, g = 0.25-0.28), RFD at predetermined time bands (p ≤ 0.001, g = 0.59-0.78), and net forces (p ≤ 0.001, g = 0.57-0.74) compared with hip175. Trivial nonsignificant differences were demonstrated between postures for PF and force at 100 ms (p > 0.05, g ≤ 0.14). Significantly greater body weights (weighing period force) were observed with hip175 compared with hip145 (p < 0.001, g = 0.74). Coaches should consider administering a hip145 for IMTP testing as greater IMTP kinetics and lower levels of pretension during the weighing period are achieved with this posture.
本研究的目的是比较在标准化膝关节角度为145°时，两个常用髋关节角度（145°[髋关节145]和175°[髋关节175]）下等长大腿中部拉伸（IMTP）的峰值力（PF）、特定时间的力值（100、150和200毫秒）、预定时间段（0 - 100、0 - 150和0 - 200毫秒）的力发展速率（RFD）以及净力。28名大学生运动员（年龄：21.7±1.5岁，身高：1.75±0.08米，体重：81.5±8.4千克）以随机平衡的顺序在每个髋关节角度进行2次IMTP测试。一个亚组（n = 10）在7天后进行IMTP测试以确定测试间的可靠性。组内相关系数（ICC）和变异系数（CV）表明，在每个姿势下所有IMTP动力学指标均具有较高的测试内可靠性和可接受的变异性（ICC≥0.86，CV≤13.7%），但髋关节175在0 - 100毫秒的RFD和100毫秒时的净力变异性较大（CV = 18.1 - 18.5%）。在每个姿势下所有IMTP动力学指标均观察到较高的测试间可靠性和可接受的变异性（ICC = 0.72 - 0.97，CV = 4.5 - 12.8%），但0 - 100毫秒的RFD在两种姿势下变异性均较大。与髋关节175相比，髋关节145产生的特定时间力值显著更高（p≤0.025，g = 0.25 - 0.28），在预定时间段的RFD显著更高（p≤0.001，g = 0.59 - 0.78），净力也显著更高（p≤0.001，g = 0.57 - 0.74）。在PF和100毫秒时的力方面，两种姿势之间显示出微小的非显著差异（p > 0.05，g≤0.14）。与髋关节145相比，髋关节175时观察到的体重（称重期力）显著更大（p < 0.001，g = 0.74）。教练在进行IMTP测试时应考虑采用髋关节145的姿势，因为这种姿势能实现更大的IMTP动力学指标以及称重期更低的预紧水平。
