Get a Stronger Core and Obliques With Side Bridges

By Stephen E. Alway, Ph.D.

The side bridge is an advanced but very effective exercise, that will active both the external and internal oblique muscles of the abdominal wall, and the quadrates lumborum, a key core muscle of the lower spine.

A weak core and a weak abdomen provide an excellent recipe for eventual back pain and injury. If your “love handles” never really retreat, and you have found twinges of pain in your lower back, even though you have pounded out sit-ups and crunches, this may be because both issues are linked. More crunches will not necessarily get the job done for either the side of the abdomen or for core training. However, if you are willing to escalate the effort ladder a bit, side bridges may be just the ticket to target your obliques while simultaneously strengthening the core muscles along the lumbar spine.

Side Bridges: Muscles Used

The oblique muscles on the side of the waist are primarily activated by side bridges. The external oblique muscle has two halves to it. Each half runs from the lower ribs by small bundles of muscle fibers that are angled in the same direction that your fingers would point, if you were to put your hands in your pockets. As the external oblique approaches the center of your abdomen, it unites with other slips of muscle fibers and forms a flat fan-shaped muscle that attaches to the iliac bones of the pelvis and hip structure. When both left and right sides of the external oblique muscles work together, they flex the trunk and move the head toward the feet. When one side contracts (unilateral contraction), the body twists or bends to that side. For example, to bend laterally toward the right side, the right external oblique is activated.

The internal oblique muscle sits just deep to the external oblique muscle. It anchors to a thick connective tissue sheath in the lower back, called the thoracolumbar fascia, and from the iliac bone of the hip. Its fibers run around the side of the trunk at right angles to the external oblique muscle, fanning out and running toward the head (superiorly). It attaches to the lowest three or four ribs and becomes continuous with the internal intercostal muscles (respiratory muscles of the rib cage).

When the left and right portions contract together, the internal oblique flexes the trunk at the waist and moves the head toward the feet. It assists in twisting the torso if it contracts unilaterally, but it acts to move the torso toward the opposite side and therefore, it works opposite to the external oblique muscle. For example, if you bend to the right side, the left internal oblique and the right external oblique are activated.

The quadratus lumborum muscle is an important core muscle that helps to stabilize the spine and when developed; it helps to prevent lower back injury and pain. The quadratus lumborum can also perform several actions, but side bridges primarily flex the vertebral column laterally. This muscle arises from a ligament attached to the ilium of the pelvis and the lumbar vertebrae called the iliolumbar ligament and the adjacent portion of the iliac crest of the pelvis. It is attached proximally (toward the head) on the lower border of the last rib and to the transverse processes of the upper four lumbar vertebrae of the spine.

Correct Exercise Form

The side bridge is an advanced but very effective exercise, that will active both the external and internal oblique muscles of the abdominal wall, and the quadrates lumborum, a key core muscle of the lower spine.

1. Start by lying on a mat on the floor with your knees and legs straight. Turn sideways and move your weight up so that you are balanced on your bent forearm and feet. Squeeze your scapula together to help provide a more solid support. The hips and feet should be stacked on top of one another.

2. Hold your torso steady, for 3-4 seconds then slowly lower your side and hip toward the floor. Continue lowering until you are just about to touch the floor. Do not let your shoulder flex downward to assist the lateral movement but keep all of the movement as lateral flexion of the spine.

3. Bring your hip and side of your ribs back up to the starting position.

Repeat for 10-20 reps; then switch to the other side.

If your back ever hurts when you roll over in bed, or when you bend forward or to the side, then side bridges may just provide the answer to reduce and prevent this pain. That is because side bridges provide an excellent core-abdominal link by strongly recruiting the quadratus lumborum and both the internal and external oblique muscles, via its activation of the lateral flexion of the spine.

Remember to lock the hips and shoulders so that they work together as one unit. Also, do not let the hip or shoulder roll forward as you are moving downward. Rather try to flex the spine laterally as you move up and down but avoid twisting forward or backward during any part of the movement.

The first few bridges will not seem too difficult at all, but after about three or four reps, things will start to be a little harder. Work up to holding each contraction for 10 seconds. Longer duration efforts are not needed, as this only increases the time without blood flow to the muscles. This can elevate oxidative stress to the working muscles and increases the risk of muscle microtraumas.

After a few months of side bridges, you should experience obliques that are firmer than they have been in a very long time. If you also tighten your diet, increase your cardio, and step up the intensity of your weight training, then be prepared to see your “love handles” start disappearing. Although unseen, the deep core muscles of the spine will also thank you, and your lower back will thank you for helping to ward off injury.


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