Choi Byung Sun, Kwon Soon Bin, Jeon Sehyeon, Kim Myeongjun, Ku Yunseo, Ro Du Hyun, Han Hyuk-Soo
Department of Orthopedic Surgery, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yeongeon-Dong, Jongno-Gu, Seoul, 03080, Korea.
Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA.
Knee Surg Relat Res. 2025 Jan 24;37(1):7. doi: 10.1186/s43019-025-00259-4.
Patellofemoral pain syndrome (PFPS) is one of the most common conditions affecting the knee joint, yet its pathomechanics remain unclear. The aim of this study was to investigate changes in muscle activation and gait patterns and to analyze the relationship between muscle activation and kinetic gait patterns in patients with PFPS.
This study included 31 patients with PFPS and 28 healthy volunteers without any symptoms. The sagittal plane motion of the knee joint, representing primary movement of the knee joint, was evaluated to identify changes in gait patterns. Electromyography (EMG) was used to measure muscle activation of vastus medialis (VM), vastus lateralis (VL), semitendinosus (ST), and gastrocnemius (GCM) muscles during gait analysis. Biomechanical features were analyzed during the three phases of the gait cycle; weight acceptance (WA), single limb support (SLS), and swing limb advancement (SLA) (0 ~ 12%, 13 ~ 50%, and 51 ~ 100% of the gait cycle, respectively).
The average knee extension moment (KEM) during WA was lower in the patient group and no significant differences were observed in the knee flexion angle (KFA). With respect to muscle activation, the patient group showed significantly higher muscle activation of the ST muscle in all phases. As the absolute value of the moment increased, the activation of the VM, VL, and ST muscles increased more rapidly in the patient group, especially when KEM was under -1% body weight × height (Bw × Ht) or over 5% Bw × Ht.
Patients with PFPS exhibit elevated muscle activation, particularly in response to changes in the knee extension moment, which is likely a compensatory mechanism to manage knee joint loading during gait. These results highlight altered neuromuscular adaptations in PFPS, suggesting targeted therapies may help improve functional outcomes. Level of evidence III, cross-sectional study.
髌股疼痛综合征（PFPS）是影响膝关节的最常见病症之一，但其病理力学仍不清楚。本研究的目的是调查PFPS患者肌肉激活和步态模式的变化，并分析肌肉激活与动力学步态模式之间的关系。
本研究纳入了31例PFPS患者和28名无症状的健康志愿者。评估代表膝关节主要运动的膝关节矢状面运动，以确定步态模式的变化。在步态分析期间，使用肌电图（EMG）测量股内侧肌（VM）、股外侧肌（VL）、半腱肌（ST）和腓肠肌（GCM）的肌肉激活情况。在步态周期的三个阶段分析生物力学特征；负重期（WA）、单腿支撑期（SLS）和摆动腿推进期（SLA）（分别为步态周期的0至12%、13至50%和51至100%）。
患者组在WA期间的平均膝关节伸展力矩（KEM）较低，膝关节屈曲角度（KFA）未观察到显著差异。在肌肉激活方面，患者组在所有阶段的ST肌肉激活均显著更高。随着力矩绝对值的增加，患者组VM、VL和ST肌肉的激活增加得更快，尤其是当KEM低于-1%体重×身高（Bw×Ht）或高于5%Bw×Ht时。
PFPS患者表现出肌肉激活增加，特别是对膝关节伸展力矩变化的反应，这可能是在步态期间管理膝关节负荷的一种代偿机制。这些结果突出了PFPS中神经肌肉适应性的改变，表明针对性治疗可能有助于改善功能结局。证据级别III，横断面研究。
