Muscles That Help Protect Our Lower Back While Keeping Our Tummies Flat

Written by: Superior Physical Therapy

Many muscles work together to provide stability and movement in our spine. Keeping these muscles healthy and exercised can help reduce the incidence of low back pain LBP.

Let’s review the muscles on the anterior or front surface of our abdomen. Starting with the long, but sectioned rectus abdominus muscle. This is a paired muscle that gives us the proverbial “6 pack”. It is the major flexor of our trunk. It is the most active during sit ups and curl ups.

Next are the 3 muscles that make up the abdominal wall. All 3 help to stabilize our lumbar spine. They also help increase intra abdominal pressure for functions such as coughing, defecation and childbirth.

The first is the external oblique muscle. If you were to place your hands on your ribs with your fingertips pointed at your navel, you would have the idea as to how these muscle fibers are oriented.

The second muscle is the internal oblique. These muscle fibers run diagonally in the opposite direction to the external oblique. These two muscles contract strongly during a sit up when the trunk is twisted to the right or left. When twisting to the right, the left external oblique and the right internal oblique contract to assist the rectus abdominus in flexing the trunk to complete the movement.

The third muscle of the abdominal wall is the transverse abdominus (TrA). It is the deepest of the three and cannot be palpated. You can, however, feel and see the effects of this muscle being exercised by attempting to draw your abdomen back toward your spine which helps to keep your abdomen flat.

To start to exercise these muscles you must first learn how to recruit them and activate them. We will address the last, the TrA. Lie on your back or side in a neutral posture (gentle curve in your low back). Gently lift your belly up away from your pelvis. There should be no movement of your hips, pelvis or spine. Once you can isolate and activate the TrA, you are ready to move on to exercises to strengthen it.

Your therapist will be helpful in guiding you on how to connect to this muscle without activating other muscles. Proper technique is crucial to getting the full benefit from this muscle. Your goal is to teach your brain to remember to use this muscle in your everyday activities.