Connecting the femur to the tibia, the knees receive considerable stress from above and below, making their stabilizing muscles and especially ligaments among the most frequently strained in physical yoga practices. Athletes, runners, even committed sitting meditators discover that the stress created in the knees from their athletic or spiritual avocation can lead to debilitating injury, especially when lacking the beneficial effects of a balanced, appropriate practice of physical asanas. Even in a balanced yoga practice, the knee still has to handle considerable forces, primarily from bearing weight but also due to twisting forces exerted from above and below. In more strenuous yoga practices, the knee has to handle very powerful physical forces. Primarily a hinge joint capable of extension and flexion, with minor capacity to rotate when flexed to about ninety degrees, sudden or excessive movement in any of these motions can tear one of the supporting ligaments or cartilage. Underst...