To loosen the tight capsule and associated ligamentous structures surrounding the hip joint and increase range of movement available.
From a push-up position, bring the bent knee of the affected leg forwards and across to the opposite side of the opposite leg. Rest the outside of the foot on the floor so that the knee and hip fall outward. The foot should be placed at roughly the level of the opposite knee.
Slowly and in a controlled manner drop the pelvis and torso toward the floor. When a stretch/tightness is felt in the hip, stop and hold for 30 seconds whilst breathing slowly and deeply. Return to starting position. The abdominal muscles should be engaged throughout the movement. Repeat on the other side.
There are many ways to stretch the hip capsule, if this exercise is too demanding, simply consult your osteopath for an alternative.