Situps are effective at strengthening your abs but for some, the lower back and tailbone can take quite a beating. Performing situps on a hard surface can cause your tailbone to rub against, and push into, the floor, making it tough to complete the exercise. Pulling your stomach in toward your spine can diminish some of the pressure on your back, but if that does not offer enough relief, there are other options for strengthening your abs without hurting your tailbone.
Complete your exercises on a carpet or padded exercise mat rather than the hard floor. Avoid using a yoga mat as well, since they tend to be thin and are designed to allow you to feel the floor beneath your feet. The padding in itself may help relieve the rubbing on your tailbone.
Place your hands under your glutes while performing the situps, which can help to release the pressure off of your tailbone and lower back. Face your palms down and place one hand under each side of the top of your butt where it meets your lower back. Keep your abs pulled in toward your spine.
Perform crunches rather than full situps. Crunches are an extremely effective abdominal exercise that allows your pelvis and lower back to remain on the ground, thus preventing any traction from movement. Bend your knees and place your feet flat on the floor. Clasp your hands behind your head and curl your head and shoulders off of the floor about 6 inches. Lower back down for one repetition.
Purchase a stability ball or use one at the gym to strengthen your abs. Along with helping you isolate your abdominal muscles, stability balls are soft and comforting on your tailbone. Lie face up with your back on a stability ball that is around 65 to 75 centimeters and plant your feet flat on the floor. Clasp your hands behind your head and curl your head and shoulders off the ball about 6 inches. Return to the starting position.
Perform alternative abs exercises such as plank pose. To execute, balance on your hands and toes, face down, with your hands directly beneath your shoulders and your legs extended straight behind you, similar to the top of a pushup. Pull your stomach in, point your tailbone down and press your shoulders away from your ears. Hold for 30 seconds.