Find a set-up where you can anchor your legs under a stable object and hang your torso down over the edge. If possible, use a back extension device for ease of use.

Place your hands behind your head and pull your elbows back to open your chest. Use your hips to arch your body slightly above parallel as you twist to one side.

Pause slightly at the top before lowering back down to the starting position. Then repeat on the opposite side.