The pyramidalis is a muscle that is located in the rectus sheath that is found in the peritoneal region of the body. This muscle is not considered to be very important in humans. In fact, a significant number of normal, healthy adults do not even have a pyramidalis muscle.
The origin of the pyramidalis muscle is at the pubic crest. The pubic crest is basically a thick, projecting ridge that forms the border of the pubic bone. From there, the pyramidalis inserts itself into the linea alba. This is a median line resembling a tendon located on the abdominal wall between the rectus muscles. The primary job of the pyramidalis is to tighten the linea alba.
The linea alba is commonly referred to as a white line. This white line consists of a line of connective tissue that extends from the pubic bone up to the breastbone. When this muscle is damaged or inflamed, it typically causes pain in the lower middle portion of the abdomen. There are several medical conditions that can cause pain in this area of the body.
The pyramidalis is not considered to be a muscle that is vital to humans. It is actually estimated that 20 percent of humans do not even have this muscle present in the body. Sometimes the pyramidalis is present on one side of the body but not the other. In other cases, there are two pyramidalis on one side, with the doubled muscles often being unequal in size. Many scientists believe that this muscle is left over from the days of humans being similar to marsupials containing pouches, and as such, has lost most of its function in the process of evolution.
Myofascial pain sometimes affects the pyramidalis muscle, causing mild to moderate pain. Myofascial pain results from a condition that causes chronic muscle pain related to various trigger points within the body. This condition can vary in intensity from mild to completely debilitating. Treatments can include medication as well as physical therapy.
Once trigger points in myofascial pain syndrome have been activated, many factors can contribute to the muscle pain. Some of these triggers can include strenuous exercise, improper posture, or even emotional stress. A condition known as fibromyalgia often accompanies myofascial pain syndrome. This can be a very debilitating condition on its own, but when present together, these muscle conditions frequently require medical supervision and management in an effort to reduce the pain and increase the body's ability to function.