Identifying yoga-based knee strengthening exercises using the knee adduction moment

Area of Science:

• Biomechanics
• Exercise Physiology
• Osteoarthritis Research

Background:

• Knee osteoarthritis (KOA) is a prevalent condition often exacerbated by exercises that increase knee adduction moments.
• Identifying safe and effective exercises for KOA management is crucial for improving patient outcomes and quality of life.

Purpose of the Study:

• To compare muscle activations, co-contraction indices, and knee adduction moments during various static standing yoga postures.
• To determine which yoga exercises may be appropriate for individuals with knee osteoarthritis by assessing biomechanical load on the knee joint.

Main Methods:

• Electromyographic (EMG) activations of key leg muscles (vastus lateralis, rectus femoris, vastus medialis, biceps femoris, semitendinosus) were measured.
• Co-contraction indices between opposing muscle groups and knee adduction moments were calculated for six static yoga postures.
• A two-factor repeated measures ANOVA analyzed differences in muscle activity, co-contraction, and knee adduction moment across postures and legs.

Main Results:

• Quadriceps and hamstring muscle activations were significantly higher in squat, lunge, and hamstring stretch postures, respectively.
• Squat and lunge postures demonstrated higher co-contraction indices, indicating greater joint stabilization.
• The wide-legged squat (Goddess) and upright lunge (Warrior) postures exhibited the lowest knee adduction moments, while single-leg balance postures showed the highest.

Conclusions:

• Squatting and lunging yoga postures show potential for enhancing leg strength while minimizing detrimental knee adduction moments.
• These findings suggest that specific yoga poses could be beneficial for knee osteoarthritis management, warranting further clinical investigation.