Pelvis is a very important part of human skeleton structure, which is mainly composed of three large pieces, namely left hip, right hip and sacrum, and some small pieces. Sometimes only one unit moves, and sometimes three blocks move together.

We have been talking about hip opening in yoga. Hip opening mostly refers to the independent movement of one part relative to the other, but the pelvis we are talking about here is actually the characteristic of the movement of the left and right hip bones and sacrum as a whole, because there is a key to opening the yoga pose correctly.

If we want to know the position of the pelvis in the anteroposterior direction, we need to look at a protruding shoulder on both sides of our hip bone, which is called the anterior superior iliac spine. Very thin people can use this bone to stab people. The correct way to judge a person's pelvic position is that when the anterior superior iliac spine protruding from both sides points forward and downward, it means that the pelvis leans forward, and if it points upward and backward, it means that the pelvis leans backward.

When we realize that this anterior superior iliac spine is very important for the practice of yoga asana, because the pelvis is the axis of the body's forward and backward movement, its position will have a great influence on the movement state of other parts of the body. When the pelvis leans forward, our posterior thigh muscles and abdominal muscles will stretch, and the lumbar spine will stretch, that is, the anterior arch, quadriceps femoris, dorsal muscles and the spine except the lumbar spine will shorten.

On the contrary, when the pelvis leans backward, the muscles in the back of thigh and abdomen will be shortened, and the quadriceps femoris and back muscles will be stretched, because the sacrum moves downward (so-called coccyx), so it moves with the waist. If our physical activity habit is leaning forward or leaning back, it will bring harm, instability or damage to some ability of our body in the long run.