Knees should be directly under your hips and hands directly under your shoulders. Keep your spine in 'neutral' and deep abdominals activated. Place the ball under one hand and take the other one hand away and place it on your lower back or abdomen. Keeping your elbow straight, slowly let your body move towards the floor, and your shoulder back - slowly letting it 'retract' (moves towards the midline of your spine.). Then push your hand into the ball and your body away from the floor, making your shoulder blade wraps around the sides of your rib cage and your shoulder moves forward. Try and perform this movement by activating the muscles underneath your armpit. The other hand can rest behind your back with your thumb on the tip of your shoulder blade so that you can feel the movement.

Try not to lean back onto your knees when pressing away from the floor - aiming to stay over your hand as much as you can. DON'T round your spine, keep it flat and make sure you keep your chest square to the wall at all times throughout the movement and do not tighten your neck muscles, keep trying to drop your shoulders away from your ears.