For decades, researchers have observed that eccentric (ECC) muscle strength is greater than concentric (CON) muscle strength. However, knowledge of the ECC:CON strength ratio is incomplete and might inform resistance exercise prescriptions. Our purposes were to determine the magnitude of the ECC:CON ratio of human skeletal muscle in vivo and explore if sex, age, joint actions/exercises, and movement velocity impact it. A total of 340 studies were identified through searches. It was possible to analyse 1516 ECC:CON ratios, aggregated from 12,546 individuals who made up 564 groups in 335 of the identified studies. Approximately 98% of measurements occurred on isokinetic machines. Bayesian meta-analyses were performed using log-ratios as response variables then exponentiated back to raw ratios. The overall main model estimate for the ECC:CON ratio was 1.41 (95% credible interval [CI] 1.38–1.44). The ECC:CON ratio was slightly less in men (1.38 [CI 1.34–1.41]) than women (1.47 [CI 1.43–1.51]), and greater in older adults (1.62 [CI 1.57–1.68]) than younger adults (1.39 [CI 1.36–1.42]). The ratio was similar between grouped upper-body (1.42 [CI 1.38–1.46]) and lower-body joint actions/exercises (1.40 [CI 1.37–1.44]). However, heterogeneity in the ratio existed across joint actions/exercises, with point estimates ranging from 1.32 to 2.61. The ECC:CON ratio was most greatly impacted by movement velocity, with a 0.20% increase in the ratio for every 1°/s increase in velocity. The results show that ECC muscle strength is ~ 40% greater than CON muscle strength. However, the ECC:CON ratio is greatly affected by movement velocity and to lesser extents age and sex. Differences between joint actions/exercises likely exist, but more data are needed to provide more precise estimates.

几十年来，研究人员观察到偏心 (ECC) 肌肉力量大于向心 (CON) 肌肉力量。然而，ECC:CON 强度比的知识是不完整的，可能会影响阻力运动处方。我们的目的是确定体内人体骨骼肌的 ECC:CON 比率的大小，并探索性别、年龄、关节动作/锻炼和运动速度是否对其产生影响。通过搜索共确定了 340 项研究。可以分析 1516 个 ECC:CON 比率，这些比率来自 335 项已确定研究中的 564 个组的 12,546 名个体。大约 98% 的测量发生在等速机器上。贝叶斯荟萃分析使用对数比率作为响应变量进行，然后取幂返回原始比率。ECC 的总体主要模型估计：CON 比率为 1.41（95% 可信区间 [CI] 1.38–1.44）。ECC:CON 比率在男性 (1.38 [CI 1.34–1.41]) 中略低于女性 (1.47 [CI 1.43–1.51])，在老年人 (1.62 [CI 1.57–1.68]) 中高于年轻人 (1.39) [置信区间 1.36–1.42]）。分组的上半身 (1.42 [CI 1.38–1.46]) 和下半身关节动作/练习 (1.40 [CI 1.37–1.44]) 之间的比率相似。然而，该比率在联合行动/演习中存在异质性，点估计值从 1.32 到 2.61 不等。ECC:CON 比率受运动速度的影响最大，速度每增加 1°/s，比率增加 0.20%。结果表明，ECC 肌肉力量比 CON 肌肉力量高约 40%。然而，ECC:CON 比率受运动速度的影响很大，受年龄和性别的影响较小。