ObjectiveTo investigate the injury risk of simplified 24-action Taiji Quan wild horse mane splitting practice at different postures with mechanical analysis. MethodsThe mechanical model of the action of Taiji Quan wild horse mane splitting was establishied, and then the coordinates, velocity, acceleration and horizontal angle of thigh and lower leg were determined by image analysis. The force arm of quadriceps femoris was detected by X-ray, and the quadriceps femoris tension, femoral tibial joint force and patellofemoral joint pressure of wild horse mane splitting practice with different postures were compared. ResultsCompared with the high posture, the coordination and velocity decreased, the average angle of knee joint decreased from 128° to 115° at the low posture; and the knee moment, the quadriceps femoris tension, femoral tibial joint force and patellofemoral joint pressure significantly increased (F > 37.187, P < 0.001). ConclusionWhen practicing Taiji Quan wild horse mane splitting, the risk of knee injury at the low posture is higher than that at high posture.