Starting Position: Lie on your side on a mat with both legs bent slightly deeper than 90 degrees at the hips, knees bent to 90 degrees, and feet overlapping each other. Align your hips and shoulder vertically with the floor and spine and head in a straight line. Extend your lower arm in front of your body at chest level, resting it upon the mat while reaching with your upper arm down under your trunk to firmly grasp your ribcage. Contract (“brace”) your abdominal muscles to stabilize your spine, depress and retract your scapulae (pull shoulders back and down) without moving your trunk and attempt to hold these positions throughout the exercise.
Gently exhale and slowly rotate your trunk by pulling the ribcage around with your upper arm. Attempt to avoid any rotation of your hips, (indicated by your upper thigh sliding backwards as you rotate). Continue rotating your trunk until your reach the point of tension, avoid bouncing or pushing to the point of pain. The deeper bend at the hips and abdominal stiffening will help prevent any arching in your low back during the stretch. Grasping under your ribcage will ensure rotation, and stretching of, your trunk and reduce shoulder stress that often occurs when the arm is extended and allowed to fall towards the floor (refer progression).
Hold this position for 15 – 30 seconds then relax and return to your starting position. Perform 2 – 4 repetitions then repeat to the opposite side.
Progression 1: Extend the lower leg, while resting the inside of the upper knee on a small riser. In this position, the upper thigh may rotate with your trunk, evidenced by a backwards slide of the upper knee during the rotation. Your objective is to stabilize your hips while only allowing rotation to occur in the trunk.
Progression 2: Remove the riser under the upper knee and place it firmly against the mat / floor. In this position, the upper knee may rise off the floor and the upper thigh may rotate with your trunk. Your objective is to stabilize your hips by pressing the knee into the floor and only allowing rotation to occur in the trunk.
Progression 3: Repeat the same exercise, but begin with both arms extended in front of your body at chest level. As you begin to rotate, bend the upper elbow, sliding it towards your trunk, then extending the arm outwards again at chest level as you continue your rotation. Continue your rotation until the point of tension in the trunk and shoulder, but avoid arching your back or rotating your hips. This will increase the stretch in the shoulder and chest region, in addition to your trunk.
To maximize the benefits of this stretch and reduce the potential for injury, it is often important to follow the instructions provided carefully.