There may be a connection between the progression of knee arthritis and instability in the frontal plane.
A new study examined 131 patients who were suffering from arthritic knees and analyzed their gait cycle. The authors found that the patients whose arthritis was grade 3 or higher demonstrated significantly more trunk asymmetry in the medio-lateral axis compared to the subjects who were only grade 2 or 3 arthritis. Furthermore, those subjects who had trunk asymmetry also appeared to have lower quadricep strength.
Conclusions
Its impossible to know whether the frontal plane instability was contributing to the arthritis, the arthritis was causing changes in gait, or if other variables such as quadricep strength were the biggest factors, but this study implies that there could potentially be a link between frontal plane stability and knee degeneration. Future intervention studies should be conducted to determine if exercises that require a high degree of frontal plane stability, such as side planks, suitcase carries, single-leg squats, and lunges, provide benefit to knee pain patients who exhibit medio-lateral axis trunk asymmetries.
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