Department of Physical Therapy, Federal University of São Carlos, São Carlos, SP, Brazil.
Physical Therapy Post-Graduate Program, Federal University of São Carlos, São Carlos, SP, Brazil.
PLoS One. 2022 Apr 27;17(4):e0267446. doi: 10.1371/journal.pone.0267446. eCollection 2022.
The patellofemoral compartment of the knee is the most frequently affected by osteoarthritis. However, there is a lack of biomechanics studies on patellofemoral osteoarthritis (PFOA). This study's purpose was to compare the frontal plane biomechanics of the trunk and lower limb during the single-leg squat and isometric hip abductor torque in individuals with isolated PFOA and controls. Frontal plane kinematics during the single-leg squat were evaluated using a three-dimensional (3-D) motion analysis system. Isometric hip abductor torque was determined using a handheld dynamometer. Twenty individuals participated in the study (10 with PFOA and 10 controls). No significant differences between groups were found regarding age (mean ± SD, PFOA group = 51.8 ± 6.9 versus control group = 47.8 ± 5.5; mean difference = 4, 95% confidence interval [CI] = -1.9 to 9.9, p = 0.20) or body mass index (PFOA group = 27.6 ± 2.2 versus control group = 25.5 ± 2.5; mean difference = 2.1, 95% confidence interval [CI] = -0.1 to 4.3, p = 0.06). Compared to control, the PFOA group presented greater hip adduction in the descending and ascending phases of the single-leg squat at 45° (mean difference [95% CI] = 6.44° [0.39-12.48°], p = 0.04; mean difference [95% CI] = 5.33° [0.24-10.42°], p = 0.045, respectively) and 60° (mean difference [95% CI] = 8.44° [2.15-14.73°], p = 0.01; mean difference [95% CI] = 7.58° [2.1-13.06°], p = 0.009, respectively) of knee flexion. No significant differences between groups were found for the frontal plane kinematics of the trunk, pelvis or knee (p > 0.05). The PFOA group exhibited lower isometric hip abductor torque (mean difference [95% CI] = -0.34 Nm/kg [-0.67 to -0.01 Nm/kg], p = 0.04). The individuals with PFOA presented greater hip adduction than the control group, which could increase lateral patellofemoral joint stress at 45° and 60° of knee flexion in the descending and ascending phases of the single-leg squat. These individuals also exhibited hip abductor weakness in comparison to healthy controls.
膝关节髌股关节面是最常受骨关节炎影响的部位。然而，对于髌股骨关节炎（PFOA），缺乏生物力学研究。本研究旨在比较孤立性 PFOA 患者和对照组在单腿深蹲和等长髋关节外展力矩时的额状面躯干和下肢生物力学。使用三维（3-D）运动分析系统评估单腿深蹲时的额状面运动学。使用手持测力计确定等长髋关节外展力矩。20 名参与者参与了这项研究（10 名 PFOA 患者和 10 名对照组）。两组在年龄（PFOA 组=51.8±6.9 岁与对照组=47.8±5.5 岁；平均差异=4，95%置信区间[CI]=-1.9 至 9.9，p=0.20）或体重指数（PFOA 组=27.6±2.2 与对照组=25.5±2.5；平均差异=2.1，95%置信区间[CI]=-0.1 至 4.3，p=0.06）方面无显著差异。与对照组相比，PFOA 组在单腿深蹲 45°（平均差异[95%CI]=6.44°[0.39-12.48°]，p=0.04；平均差异[95%CI]=5.33°[0.24-10.42°]，p=0.045）和 60°（平均差异[95%CI]=8.44°[2.15-14.73°]，p=0.01；平均差异[95%CI]=7.58°[2.1-13.06°]，p=0.009）时的下降和上升阶段髋关节内收更大。在躯干、骨盆或膝关节的额状面运动学方面，两组之间无显著差异（p>0.05）。PFOA 组的等长髋关节外展力矩较低（平均差异[95%CI]=-0.34 Nm/kg[-0.67 至-0.01 Nm/kg]，p=0.04）。与对照组相比，PFOA 患者的髋关节内收更大，这可能会增加单腿深蹲下降和上升阶段膝关节 45°和 60°时外侧髌股关节的压力。与健康对照组相比，这些患者还表现出髋关节外展肌无力。
