Abdominal Muscles and Back Pain

Abdominal trigger points can refer to the low back

Many people are aware that the abdominal muscles have something to do with back pain and this awareness is centered around 'core' support and the role of these abdominal muscles in back support. While this is certainly the case, my patients are less aware that the abdominal muscles can be directly tied to the back pain they experience. The rectus abdominis specifically can harbor trigger points, or sensitive contractile knots, that can cause pain not necessarily in the abdomen, but can instead refer pain to the back.

Regardless if you have a developed rectus abdominis or not, this is the muscle that people refer to when the discuss a 'six pack' ab. Technically, there are four grouping of muscles on either side, and each of these compartment are bordered by a tendinous intersection. The upper compartment is lies over the lower ribcage and this compartment is less visible when people do have 'six pack abs', so you are really seeing the lower three compartments on either side.

The rectus abdominis attaches from the pubic bone to the lower ribcage and sternum. The muscle is involved with flexion of the trunk, forced exhale and compression of the abdominal organs.

While it is actively involved in forced expiration or exhale, when the muscle becomes rigid and restricted, it can reduce the ability to take a good, deep inhale and this is most frequently the case when this muscle becomes a component of low back pain.

There is a characteristic referral pattern when this muscle is contributing to back pain which can be seen on the image to the right. The low back portion of the refer specifically usually is associated with trigger points in the umbilical region, in my opinion, and they can frequently even occur in the tendinous intersection in this region. This image to the right shows and X at the pubic bone attachment which can also occur, but I still find this occurs more frequently at the umbilical region. The mid back pain referral is more often at the region just below the lower ribcage and close to the xiphoid process which is the lowest part of the sternum or breastbone.

Many people with low back pain will look at the referral that travels across the low back/upper pelvic region and say, 'That describes my back pain!" It could be the case, then that the rectus abdominis is a contributor. It is the case, thought, that there are other frequently causes of this horizontal distribution of low back pain. Specifically, the joints of the lower spine, referred to as facet joints, can become irritated and cause a similar pain distribution. Below is and image that illustrates this referral pattern and you can see that there is some overlap.

It can be a combination of causes, all contributing to the pain that brings people in to see me. Palpation can be used to see if this muscle is referring pain, but there are also other clues. Urinary problems, digestive disturbances, and dysmenorrhea (painful periods) can all be associated with trigger points in the rectus abdominis. Clinically, it is worth investigating if this important muscle is contributing to the back pain and other problems, and then adding protocols to treat it into the mix. Acupuncture, dry needling, manual therapy and specific corrective exercises are all helpful and tools I use for this trigger points in this muscle and for back pain in general.

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