University of Primorska, Faculty of Health Sciences, Izola, Slovenia; InnoRenew CoE, Livade 6, 6310 Izola, Slovenia; University of Primorska, Andrej Marušič Institute, Koper, Slovenia; S2P, Science to Practice, Ltd., Laboratory for Motor Control and Motor Behaviour, Ljubljana, Slovenia.
University of Primorska, Faculty of Health Sciences, Izola, Slovenia.
Knee. 2020 Dec;27(6):1697-1707. doi: 10.1016/j.knee.2020.09.023. Epub 2020 Nov 13.
The linear relationship between muscle torque and rate of torque rise/relaxation during rapid muscle contractions has been recently introduced as a novel measure of muscle quickness, termed rate of torque development/relaxation scaling factor (RTD-SF/RTR-SF). Because the standard assessment protocol includes potentially painful muscle contractions, the first purpose of this study was to validate an adapted RTD-SF/RTR-SF protocol for knee extensor muscles that utilizes lower submaximal intensities and can be used in knee osteoarthritis patients.
A cross-sectional study was performed on a group of healthy controls (n = 24) who underwent the standard RTD-SF/RTR-SF protocol (20-80% of maximum) and the knee osteoarthritis group (n = 24) who underwent the adapted protocol (20-60% of maximum). We calculated the RTD-SF, RTR-SF and the linearity (r) for both relationships, based on both protocols in controls.
The validity of the adapted protocol was acceptable (intraclass correlation coefficient = 0.77-0.93), with low within-participant variation (coefficient of variability <10%) for both outcome measures. Compared with the control group, the knee osteoarthritis group had similar RTD-SF, but lower linearity of RTD-SF (0.90 vs. 0.82). The RTR-SF (8.0/s vs. 6.7/s) and its linearity (0.87 vs. 0.73) were significantly reduced. Comparing the affected and the unaffected leg in the knee osteoarthritis group, the unaffected leg had greater maximal torque (96.2 vs. 84.1 Nm) and higher linearity for RTD-SF (0.86 vs. 0.80) and RTR-SF (0.82 vs. 0.73).
We confirmed the validity of the adapted RTD/RTR-SF protocol and its sensitivity to impairments associated with knee osteoarthritis.
最近提出了一种新的肌肉快速性测量方法，即肌肉扭矩和快速肌肉收缩时的扭矩上升/松弛速率之间的线性关系，称为扭矩发展/松弛速率标度因子（RTD-SF/RTR-SF）。由于标准评估方案包括潜在的疼痛性肌肉收缩，因此本研究的首要目的是验证一种适用于膝关节伸肌的改良 RTD-SF/RTR-SF 方案，该方案使用较低的亚最大强度，并且可以用于膝骨关节炎患者。
对一组健康对照组（n=24）进行了横断面研究，他们接受了标准的 RTD-SF/RTR-SF 方案（20-80%最大），膝骨关节炎组（n=24）接受了改良方案（20-60%最大）。我们根据对照组中两种方案计算了 RTD-SF、RTR-SF 和两种关系的线性度（r）。
改良方案的有效性是可以接受的（组内相关系数=0.77-0.93），两种结果测量的个体内变异性均较低（变异系数<10%）。与对照组相比，膝骨关节炎组的 RTD-SF 相似，但 RTD-SF 的线性度较低（0.90 比 0.82）。RTR-SF（8.0/s 比 6.7/s）及其线性度（0.87 比 0.73）显著降低。在膝骨关节炎组中比较患侧和健侧，健侧的最大扭矩更大（96.2 比 84.1 Nm），RTD-SF 和 RTR-SF 的线性度更高（0.86 比 0.80 和 0.82 比 0.73）。
我们证实了改良的 RTD/RTR-SF 方案的有效性及其对膝骨关节炎相关损伤的敏感性。
