Lie on your back with legs straight and lift your arms up towards the ceiling.
You may find having bed rails up is helpful for safety.
Keeping your legs straight start moving your arms from side-to-side and rocking your top half from side-to-side to side to generate momentum.
When you are ready, take your arms all the way across your body towards the side you are rolling, using momentum to help you onto your side.
Hold the position.
Return back to the starting position and repeat.
