Department of Sport Sciences, University of Beira Interior, 6201-001, Covilhã, Portugal.
Escola Superior de Educação, Instituto Politécnico de Setúbal, Setúbal, Portugal.
Sci Rep. 2024 Oct 10;14(1):23727. doi: 10.1038/s41598-024-74159-0.
The current study aimed to analyze the validity and reliability of the T-Force and Chronojump systems to measure the movement velocity in the leg press (LP) and chest press (CP) exercises in older people. Eighteen older adults (6 men and 12 women, 79.9 ± 8.5 years) performed a set of procedures over three weeks: (i) the first week was to familiarize participants with the testing procedures, (ii) the second was to perform a progressive loading test until reaching one-repetition maximum (1RM) in the LP and CP, and (iii) in the third week, participants performed three repetitions against five loads (40, 50, 60, 70, and 80% of 1RM). The mean velocity of each repetition was recorded simultaneously through the T-Force and Chronojump devices. Linear regressions (coefficient of determination [r] and standard error of the estimate [SEE]) analyzed the inter-device validity, and Bland-Altman plots illustrated the systematic differences between devices. A mixed-effects model estimated the mean velocity differences between devices. The relative reliability was analyzed by the intra-class correlation coefficient (ICC[1,k]), while the absolute reliability was by the standard error of measurement (SEM) and the coefficient of variation (CV). The results showed that the T-Force and Chronojump presented a high association level in measuring mean velocity in the LP and CP (r range: 0.96-0.99; SEE range: 0.01-0.02 m·s) and low systematic bias (0.02-0.03 m·s). The mean velocity values of T-Force were significantly higher than Chronojump only for 40% 1RM (p = 0.04). Excellent reliability inter-device (ICC range: 0.95-0.98; CV range: 1.7-3.2%) and intra-device (ICC range: 0.90-0.97; CV range: 3.4-6.5%) was observed. This study shows that the T-Force and Chronojump systems are valid and reliable for measuring movement velocity in the CP and LP machines when used by older adults.
本研究旨在分析 T-Force 和 Chronojump 系统在测量老年人腿推（LP）和卧推（CP）练习中运动速度的有效性和可靠性。18 名老年人（6 名男性和 12 名女性，79.9±8.5 岁）在三周内完成了一系列程序：（i）第一周让参与者熟悉测试程序，（ii）第二周进行渐进式加载测试，直到达到 LP 和 CP 的一次重复最大重量（1RM），（iii）在第三周，参与者在五个负载（40、50、60、70 和 80%的 1RM）下进行了三次重复。通过 T-Force 和 Chronojump 设备同时记录每个重复的平均速度。线性回归（决定系数 [r] 和估计标准误差 [SEE]）分析了设备间的有效性，Bland-Altman 图说明了设备之间的系统差异。混合效应模型估计了设备之间的平均速度差异。通过组内相关系数（ICC[1,k]）分析相对可靠性，通过测量标准误差（SEM）和变异系数（CV）分析绝对可靠性。结果表明，T-Force 和 Chronojump 在测量 LP 和 CP 的平均速度时具有高度关联（r 范围：0.96-0.99；SEE 范围：0.01-0.02 m·s）和低系统偏差（0.02-0.03 m·s）。T-Force 的平均速度值仅在 40% 1RM 时明显高于 Chronojump（p=0.04）。设备间和设备内的可靠性都非常好（ICC 范围：0.95-0.98；CV 范围：1.7-3.2%）和（ICC 范围：0.90-0.97；CV 范围：3.4-6.5%）。本研究表明，T-Force 和 Chronojump 系统在老年人使用时可有效可靠地测量 CP 和 LP 机器中的运动速度。
