A back extension is a strength training exercise that is designed to help strengthen the extensor muscles of the back. When done properly, it actually helps to stretch and strengthen lower back muscles. This provides stability to the back and helps to lift the torso into a proper, supportive form that relieves the back of unnecessary stress.
A back extension can be executed either lying down or standing up. People who have lower back problems or age-related issues might prefer to try this exercise standing up. The standing version is best for osteoporosis prevention, particularly for women who are postmenopausal. Runners and cyclists tend to prefer the lying down version of this exercise for optimal conditioning and strength training.
For people who need or want to start out more easily, performing standing back extensions is ideal. This is recommended for anyone who is concerned about injury. Over time, as the back is strengthened and additional bone mass has been developed, increased repetitions and the addition of some weights may be recommended.
To perform a standing back extension, a person should begin by standing with the back against a wall. A small, 8-inch (20.32 cm) rubber ball should be placed between the small of the back and the wall. Another rubber ball should be placed between the knees. Hands should hang down at the sides with a dumbbell weight in each hand; the weight of the dumbbells should be heavy enough to "feel," but not heavy enough to cause undue strain.
With the feet positioned in front of the body, the person should then squat to a 90-degree angle, with knees and thighs parallel to the floor. The legs should then be straightened to the starting position, pressing body weight into the heels. The knees should not be locked. The back should be lengthened, and abdominals kept tight with each movement.
To perform a back extension while lying down, the person should find a padded bench that has feet that can be anchored to the floor. It will also be necessary to ensure that there is enough clearance for the bending down, or lowering motion. The person should lie face down on the bench with the torso hanging off one end. The lower body should remain tightened to maintain balance.
The hands should then be clasped behind the head and the person should bend at the waist in an up and down movement that is smooth and controlled. For added resistance, small weight plates can be added, to be held behind the neck. This should only be done by people who are certain that they are strong enough to handle the additional weight.
The most important thing to remember is that neither of these exercises should ever be painful. Anyone who experiences pain should stop and consult his or her personal trainer or physician.