You'll need some specialized equipment for this exercise. A back extension machine consists of a large, single pad for you to rest your hips on, two pads behind you that you'll use to support your weight and two metal plates for your feet. Start by positioning your lower abdomen and hips on the larger pad with your legs extended behind you. Your calves should be butted up against the two smaller pads with your feet firmly planted on the plates. Extend your body beyond the machine so you can easily bend at the waist. Once you're comfortable, hug your arms across your chest and lower your torso slowly toward the ground, then raise your torso back up slowly.
Take this exercise slow so you don't overextend yourself and risk pulling a muscle. To increase the difficulty level, hold a small weight against your chest as you perform the exercise [source: Body Building].