I have been going to the gym for the last 6 weeks after a break for about 12 months. I had increasing pain especially after a workout, had an MRI scan done, and found out I have Schuermanns disease of the spine. I cannot sit properly due to a bulging disc near the cocyx bone, and my back aches constantly.. Does anyone have any ideas on good exercises to help core stomach muscles, as I cannot lay on the floor, and cant do planks because of tennis elbow !.. Help !!!