Graduate School of Rehabilitation Sciences, Health Sciences University of Hokkaido, 1757 Kanazawa, Tobetsu-cho, Ishikari-gun, Hokkaido 061-0293, Japan.
Department of Physical Therapy, School of Rehabilitation Sciences, Health Sciences University of Hokkaido, 1757 Kanazawa, Tobetsu-cho, Ishikari-gun, Hokkaido 061-0293, Japan.
Gait Posture. 2019 Oct;74:108-113. doi: 10.1016/j.gaitpost.2019.08.021. Epub 2019 Aug 29.
Individuals with knee osteoarthritis (OA) show various dynamic sagittal-plane changes during the early stance phase of gait. However, the effect of these kinematic alterations on knee load during the early stance remains poorly understood.
The purpose of this study was to examine the effect of altered sagittal- plane knee kinematics on knee load during the early stance.
A total of 13 healthy adult men underwent gait analysis trials using four conditions (baseline and three altered conditions). The three altered conditions were defined as follows: 1) Less flexion (LF): a gait that decreased knee flexion excursion (KFE) owing to a reduced peak knee flexion angle compared to baseline. 2) Initial flexion (IF): a gait with decreased KFE owing to an increased knee flexion angle at initial contact, during which the peak knee flexion angle did not differ from baseline. 3) Flexion gait (FG): a gait that increased the knee flexion angle at initial contact but did not reduce KFE compared with the baseline. Data analyzed included peak external knee flexion moment (KFM), KFM impulse (impulse was an integral value from initial contact to peak value), peak vertical ground reaction force (VGRF), and maximum loading rate.
Both LF and IF conditions significantly decreased peak VGRF (p < 0.05) compared with the baseline. Peak KFM decreased in the LF condition and increased in the FG condition versus baseline (p < 0.05). A significantly increased KFM impulse was found in both IF and FG conditions when compared with baseline (p < 0.05).
An increase in knee flexion angle during early stance increased knee loading. Interventions are likely required for improving excessive knee flexion during early stance phase of gait in individuals with knee OA.
膝骨关节炎（OA）患者在步态的早期支撑阶段表现出各种矢状面动态变化。然而，这些运动学改变对早期支撑阶段膝关节负荷的影响仍知之甚少。
本研究的目的是探讨矢状面膝关节运动学改变对早期支撑阶段膝关节负荷的影响。
共有 13 名健康成年男性参与了步态分析试验，共 4 种条件（基线和 3 种改变条件）。这三种改变条件如下：1）屈曲减少（LF）：与基线相比，由于峰值膝关节屈曲角度减小导致膝关节屈曲行程（KFE）减少的步态。2）初始屈曲（IF）：由于初始接触时膝关节屈曲角度减小导致 KFE 减小的步态，在此期间峰值膝关节屈曲角度与基线无差异。3）屈曲步态（FG）：一种与基线相比增加初始接触时膝关节屈曲角度但不减少 KFE 的步态。分析的数据包括最大膝关节外展力矩（KFM）、KFM 冲量（冲量是从初始接触到峰值的积分值）、垂直地面反作用力峰值（VGRF）和最大加载率。
与基线相比，LF 和 IF 条件均显著降低了峰值 VGRF（p<0.05）。与基线相比，LF 条件下的 KFM 峰值降低，FG 条件下的 KFM 峰值增加（p<0.05）。IF 和 FG 条件下的 KFM 冲量均明显高于基线（p<0.05）。
在早期支撑阶段膝关节屈曲角度的增加增加了膝关节的负荷。对于膝骨关节炎患者在步态的早期支撑阶段过度膝关节屈曲，可能需要进行干预以改善这种情况。
