To lengthen and relax the muscles at the front of the pelvis in order to increase mobility at the hip joint and help with overall posture.
Adopt a lunging position on a flat surface with the hip and knee of the unaffected leg bent more than 90° so that the foot is pointing directly forwards. You may place a cushion under the knee of the other leg which is in contact with the floor. The hands can be placed on the hips, or on a support in front of you such as a chair or table.
Slowly and in a controlled manner drive the pelvis forwards whilst the knee of the affected side remains on the floor. When a stretch is felt at the front of the hip, hold for 30 seconds whilst breathing slowly and deeply. Return to the starting position and repeat on the other side.
The torso should remain vertical at all times to protect the lower back. Make sure to keep a straight line between the hip, knee and ankle of the side being stretched.