Department of Physical Therapy, Faculty of Rehabilitation, Niigata University of Health and Welfare, Niigata, Japan.
Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
PLoS One. 2022 Jan 11;17(1):e0262508. doi: 10.1371/journal.pone.0262508. eCollection 2022.
Knee osteoarthritis (KOA) is a leading cause of knee pain and disability due to irreversible cartilage degeneration. Previous studies have not identified modifiable risk factors for KOA. In this preliminary cross-sectional study, we aimed to test the following hypotheses: individuals with severe KOA would have a significantly lower quadriceps rate of force development (RFD) than individuals with early KOA, and the decrease in quadriceps RFD would be greater than the decrease in maximum quadriceps strength in individuals with severe KOA. The maximum isometric strength of the quadriceps was assessed in individuals with mild (Kellgren and Lawrence [K&L] grade 1-2) and severe KOA (K&L grade 3-4) using a handheld dynamometer. The RFD was analyzed at 200 ms from torque onset and normalized to the body mass and maximum voluntary isometric contraction torque. To test whether the quadriceps RFD was lowered and whether the lower in the quadriceps RFD was greater than the lower in maximum quadriceps strength in individuals with severe knee OA, the Mann-Whitney U-test and analysis of covariance were performed, respectively. The effect size (ES) based on Hedges' g with a 95% confidence interval (CI) was calculated for the quadriceps RFD and maximum quadriceps strength. Sixty-six participants were analyzed. Individuals with severe KOA displayed significantly lower quadriceps RFD (p = 0.009), the lower being greater than the lower in maximum quadriceps strength (between-group difference, ES: 0.88, -1.07 vs. 0.06, -0.22). Our results suggest that a decreased quadriceps RFD is a modifiable risk factor for progressive KOA. Our finding could help in the early detection and prevention of severe KOA.
膝骨关节炎（KOA）是导致膝关节疼痛和残疾的主要原因，其原因是软骨不可逆转的退化。以前的研究尚未确定 KOA 的可改变危险因素。在这项初步的横断面研究中，我们旨在验证以下假设：患有严重 KOA 的个体的股四头肌肌力发展率（RFD）明显低于患有早期 KOA 的个体，并且在严重 KOA 个体中，股四头肌 RFD 的下降幅度大于最大股四头肌力量的下降幅度。使用手持测力计评估轻度（Kellgren 和 Lawrence [K＆L] 1-2 级）和严重 KOA（K＆L 3-4 级）个体的股四头肌最大等长强度。在扭矩开始后的 200ms 处分析 RFD，并将其归一化为体重和最大自愿等长收缩扭矩。为了测试严重膝骨关节炎患者的股四头肌 RFD 是否降低，以及股四头肌 RFD 的降低是否大于最大股四头肌强度的降低，分别进行了 Mann-Whitney U 检验和协方差分析。根据 Hedges'g 计算了股四头肌 RFD 和最大股四头肌强度的效应大小（ES），置信区间（CI）为 95％。分析了 66 名参与者。患有严重 KOA 的个体的股四头肌 RFD 明显较低（p = 0.009），下降幅度大于最大股四头肌强度的下降幅度（组间差异，ES：0.88，-1.07 vs. 0.06，-0.22）。我们的结果表明，股四头肌 RFD 的降低是进展性 KOA 的可改变危险因素。我们的发现有助于早期发现和预防严重 KOA。
