Clam Shells Vs. Leg Raises

Clamshell and leg-raise exercises both focus on moving the legs, but they strengthen different groups of muscles. When done properly, the clamshell is not likely to put stress on the back, but leg raises have the potential to strain lower back muscles. Talk to your physician before doing these exercises, especially if you’ve had any prior back, hip or spine problems.

Clamshell

Clamshell exercises are aptly named because your leg movements resemble a clamshell opening and closing. Begin by lying on your side, with your knees bent, using one arm to support your head and the other arm bent with your hand placed on your hip. It’s important to keep the hips and upper body in straight alignment and perpendicular to the floor, so it may help to do this exercise with your back and feet against a wall. Keeping your feet together, lift your top knee up as though your legs are opening like a clamshell, then lower it back down, moving slowly so that you carefully work the appropriate muscles. Don’t lift your leg so high that you roll backward. Perform eight to 15 repetitions on each side, depending on your ability.

Leg Raise

Lie flat on your back with arms relaxed at your sides and bring one leg up, bending the knee at about a 90-degree angle. Keep that foot flat on the floor as you raise the other leg. Keep the leg straight and lift it off the floor to about the height of your bent knee, then lower it back to the floor. Do the lifts using controlled motion. You should feel the quadriceps muscles working, but you should never feel any stress or pain in your back. Aim for 10 repetitions on each side and build up to three to five sets.

Comparison

The clamshell is a good exercise for strengthening the hip abductor muscles. This muscle group is responsible for moving the leg out to the side and includes the gluteus muscles. Strengthening the gluteus muscles helps stabilize the spine and relieve low back pain. Strong hip abductors also balance the pelvis during body movement. Leg raises primarily strengthen the quadriceps and secondarily build abdominal muscles. The term "quadriceps" refers to a group of four muscles on the front of the thigh. They’re obviously important for walking, running, jumping and squatting, but the quadriceps also have the important role of stabilizing your knee during movement.

Consideration

It’s always important to follow proper form and technique when you exercise because that guarantees you work the appropriate muscles without straining other muscles. This is especially important when performing leg raises because they can easily strain your lower back muscles. You'll minimize the risk by raising one leg at a time, while keeping the other leg bent because raising both legs at the same time hyperextends your lower back. Stop immediately if you have any pain in your back and take it easy for a few days to give the muscles time to recover. If the pain continues, talk to your physician.