Weakness in the hamstrings makes it hard to create a neutral extension of the hip joints, so many people use the quadriceps to extend the knee and push the foot into the floor. The problem here is that this tends to also create hip flexion, which obstructs the opening at the front of the hip joint. Overusing the gluteus maximus will also externally rotate the hip, which the adductors will counter, creating even more restriction at the hip joint.

Too much tightness in the pectoral region will prevent the scapulae from moving into position (adduction) and will result in either too much movement in the glenohumeral joint or flexion of the spine, which will challenge the breathing.

If the chest is able to rise effectively in relation to the shoulder girdle, the base of the skull can (in most people) find a resting place on a “shelf” that’s formed by the upper trapezius muscles. This can provide a very nice release of the anterior neck structures without the risk of hyperextending the cervical spine (see a similar effect in ustrasana).