The aim of the study was to investigate whether the MME during walking is correlated with knee muscle co-contraction in knee OA.
Twenty-nine patients who were diagnosed with primary unilateral or bilateral medial tibiofemoral knee OA with varus alignment (OA group: mean age: 63.5 ± 9.8 years) and 13 healthy elderly volunteers (control group: mean age: 59.7 ± 8.4 years) were enrolled in this study. The MME and kinematic data were measured using ultrasound and a three-dimensional motion analysis system, synchronously. In especially, the amount of MME was described the behavior of MME as the ΔMME, and calculated the difference between the minimum and maximum MME during walking. The electromyographic data of quadriceps and hamstrings were recorded, and the co-contraction index (CCI) was calculated in the first 50% of the stance phase. The correlation between CCI and ΔMME was compared between groups using Pearson correlation coefficient or Spearman's rank correlation coefficient.
The maximum value of MME and ΔMME in the OA group were significantly greater than those in the control group (p0.01). In the OA group, the lateral and medial CCI had significant correlations with ΔMME (lateral: r=0.384, p0.05, medial: r=0.566, p0.01), but not those in the control group.
The behavior of MME during walking is correlated with co-contraction of knee muscles, in especially medial compartments within knee joint in knee OA patients.
Our findings contribute to describe the mechano-pathology for MME, and it would emphasize the need to control the imbalance of knee muscles during walking on the medial compartment of the knee joint.
knee osteoarthritis
knee mechano-pathology
