Faculty of Sport, Allied Health and Performance Science, St Mary's University, London, United Kingdom.
Arsenal Performance and Research Team, Arsenal Football Club, London, United Kingdom.
Int J Sports Physiol Perform. 2024 Oct 1;19(12):1444-1454. doi: 10.1123/ijspp.2023-0473. Print 2024 Dec 1.
To examine the test-retest reliability of countermovement jump (CMJ) and isometric strength testing measures in elite-level under-18 and under-23 academy football players.
A total of 36 players performed 3 maximal CMJs and isometric abductor (IABS), adductor (IADS), and posterior chain (IPCS) strength tests on 2 separate test days using dual force plates (CMJ and IPCS) and a portable strength testing device (IABS and IADS). Relative (intraclass correlation coefficient) and absolute (coefficient of variation, standard error of the measurement, and minimal detectable change [MDC%]) reliabilities for 34 CMJ, 10 IABS, 10 IADS, and 11 IPCS measures were analyzed using between-sessions best, mean, and within-session methods.
For all methods, relative reliability was good to excellent for all CMJ and all IADS measures and poor to good for all IABS and IPCS measures. Absolute reliability was good (ie, coefficient of variation < 10%) for 27 (best) and 28 (mean) CMJ variables and for 6 (IABS and IADS) and 2 (IPCS) isometric measures. Commonly used CMJ measures (jump height, eccentric duration, and flight-time:contraction-time ratio) had good to excellent relative reliability and an MDC% range of 14.6% to 23.7%. Likewise, commonly used isometric peak force measures for IABS, IADS, and IPCS had good to excellent relative reliability and an MDC% range of 22.2% to 26.4%.
Commonly used CMJ and isometric strength measures had good test-retest reliability but might be limited by their MDC%. Rate-of-force-development measures (for all isometric tests) and impulse measures (IPCS) are limited by poor relative and absolute reliability and high MDC%. MDC% statistics should be considered in the context of typical responsiveness.
研究青少年精英足球运动员在反跳（CMJ）和等长力量测试中的测试-重测可靠性。
共有 36 名运动员在 2 天的测试中分别使用双力板（CMJ 和 IPCS）和便携式力量测试设备（IABS 和 IADS）进行了 3 次最大 CMJ 和等长外展肌（IABS）、内收肌（IADS）和后链（IPCS）强度测试。使用组内最佳、平均和组内方法分析了 34 个 CMJ、10 个 IABS、10 个 IADS 和 11 个 IPCS 测量值的相对（组内相关系数）和绝对（变异系数、测量标准误差和最小可检测变化 [MDC%]）可靠性。
对于所有方法，所有 CMJ 和所有 IADS 测量值的相对可靠性均为良好至优秀，而所有 IABS 和 IPCS 测量值的相对可靠性为差至良好。对于 27 个（最佳）和 28 个（平均）CMJ 变量以及 6 个（IABS 和 IADS）和 2 个（IPCS）等长测量值，绝对可靠性良好（即变异系数 < 10%）。常用的 CMJ 测量值（跳高度、偏心持续时间和飞行时间：收缩时间比）具有良好至优秀的相对可靠性，MDC%范围为 14.6%至 23.7%。同样，IABS、IADS 和 IPCS 的常用等长峰值力测量值具有良好至优秀的相对可靠性，MDC%范围为 22.2%至 26.4%。
常用的 CMJ 和等长力量测量值具有良好的测试-重测可靠性，但可能受到其 MDC%的限制。力发展率测量值（所有等长测试）和冲量测量值（IPCS）受到相对和绝对可靠性差以及 MDC%高的限制。在考虑典型反应性的情况下，应考虑 MDC%统计数据。
