The hip joint is a very deep ball-and-socket joint, meant to extend, flex and rotate. Thus, if the hip is sufficiently flexible, it will be able to rotate and flex enough to take strain off the knee joint, especially in the cross-legged sitting poses. It's not that easy, however, for the hip has some of the strongest ligaments in the body, which prevent the femur (thigh bone) from being dislocated. The cost of this stability/however, is decreased mobility.

It takes careful, consistent practice to increase this limited range of motion, as we lengthen the muscles in the hip region and gently stretch the ligaments. This is the key to being comfortable and anatomically safe in the cross-legged sitting postures. The knee should swing out to the side and down to the floor through a lateral rotation in the hip socket. To move to half or full lotus position, in which one or both ankles come up onto the thigh(s), it is imperative that this movement take place only through further lateral rotation of the hip joint, not through twisting the knee joint.

Remember: never force the knees into a yoga posture. Move carefully and slowly with patience and concentration. Use the breath to help release the hip joints.