Home Health-Fitness Core plus your upper back and shoulders? Place your heels against the bottom of a wall, bend forward, and position your hands shoulder-width apart on the floor. Walk your feet up the wall until your legs are parallel to the floor and your body forms a 90-degree angle (a); this works your upper back and shoulders. Raise your right leg to activate your core (b). Reverse to return to start. Thats one rep. Do 10. #FitLiving