重力校正与膝关节等速扭矩参数及腘绳肌/股四头肌（H:Q）比值：基于大样本前交叉韧带（ACL）队列的参考方程
简介
该研究基于439例ACL断裂患者，在不同角速度下比较了膝关节等速肌力测试中重力校正与否对峰力矩及腘绳肌/股四头肌（H:Q）比值的影响。结果显示，重力校正后伸肌力矩增加、屈肌力矩和H:Q比值显著降低，且速度越快差异越大；据此建立了换算参考方程，但H:Q方程在高速度下误差较大，应用需谨慎。该方程有助于不同测试方案间数据比较，但临床解读时应注意其适用条件。
英文摘要
BACKGROUND: Inconsistency in applying gravity-correction during knee isokinetic dynamometry limits direct comparisons across sports medicine literature. This study aimed to develop and internally validate reference equations relating knee peak torque parameters measured with and without gravity correction in an anterior cruciate ligament (ACL) cohort. METHODS: 439 individuals with a confirmed ACL rupture underwent concentric isokinetic knee extension and flexion testing at 60, 180, and 300°/s using a HUMAC Norm dynamometer. Peak torque values and hamstring-to-quadriceps (H:Q) ratios were calculated using both gravity-corrected and uncorrected protocols. Relationships were modelled using linear mixed-effects models with a participant-level random intercept, fitted separately by sex, velocity and outcome. RESULTS: Gravity-corrected extensor torque was 4.2-11.1% greater, flexor torque 13.1-25.5% smaller, and H:Q ratios 17.2-33.1% smaller than uncorrected values, with differences increasing with angular velocity. Marginal R2 ranged from 0.95 to 0.99 for knee extensors, 0.90 to 0.97 for knee flexors, and 0.68 to 0.87 for H:Q ratios. Cross-validated prediction error was small for torque (RMSE 3.3-5.1 Nm; LoA ± 6.5 to ± 10.0 Nm) but larger and velocity-dependent for the H:Q ratio (RMSE 3.6-7.9 percentage points; LoA ± 7.1 to ± 15.5 points). CONCLUSIONS: These equations provide an internally validated reference for approximating peak torque between gravity-corrected and non-gravity-corrected protocols within a comparable cohort and testing set-up; the H:Q equations should be applied with caution, particularly at higher velocities. Neither protocol is inherently superior, but explicit reporting of whether gravity correction was applied is essential to avoid confounding when datasets are compared or pooled.