Stand side on to the wall with a stability ball between your leg and the wall.
Press your inside leg against the ball and lift your leg up with your knee bent.
Gently push the ball against the wall with this leg.
Bend the leg you are standing on and move into a slight squat.
Maintain the squat and move your leg with the ball backwards, moving through the hip.
As your leg moves backwards rotate your shoulder nearest the wall away and across your body in the direction of your standing leg by twisting through your upper back.
This exercise is a component of effective and efficient running.