Associations of muscle coactivation patterns with gait, muscle strength, and symptoms across different stages of knee osteoarthritis
摘要
This study aimed to investigate associations between neuromuscular activation patterns, symptoms, muscle strength, and gait parameters across different stages of knee osteoarthritis (KOA).
MethodsIn this cross-sectional study, 165 unilateral KOA patients and 32 healthy controls underwent synchronized gait analysis, isokinetic strength testing, surface electromyography, and completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. Muscle coactivation was quantified as the normalized electromyographic (EMG) ratio of antagonist to agonist muscles during gait phases and isokinetic contractions. Group comparisons were performed using one-way ANOVA with Bonferroni correction. Spearman correlations and multiple linear regression models examined relationships between muscle activation, biomechanical parameters, and WOMAC scores.
ResultsCompared with controls, patients with KOA showed progressively deteriorating gait patterns and strength performance with increasing K-L grades (p < 0.05). A distinct compensatory neuromuscular pattern, characterized by excessive coactivation of the hamstrings (particularly the lateral hamstring) and the vastus lateralis, was identified (p = 0.002–0.048). This pattern was significantly associated with reduced knee flexion moment and elevated knee adduction moment (p = 0.004–0.038). These changes were observable from K-L II and became more pronounced in advanced KOA (K-L ≥ III), correlating with higher WOMAC pain, stiffness, and functional scores (p < 0.001–0.046). Significant inter-limb asymmetry was observed between affected and contralateral limbs (asymmetry index [ASI] = 1.72–13.84; limb symmetry index [LSI] = 56.3–92.7%).
ConclusionsKOA is associated with an adaptive neuromuscular strategy characterized by excessive hamstring coactivation. While this pattern may aim to stabilize the joint, it correlates with biomechanical inefficiency, symptom worsening, and functional decline. This coactivation pattern may serve as a promising biomechanical marker for better understanding KOA manifestations and warrants further investigation as a potential therapeutic target.