The multifidus muscle is a long muscle that travels the length of the spine. It has different actions on different parts of the spine. It extends and laterally flexes the cervical and lumbar spine, and rotates the thoracic spine. Trigger points in this muscle are common due to poor posture and bad movement mechanics. Trigger points in the lumbar area area are a common cause of low back pain. These lower points can also refer into the abdomen. Points that form in the cervical region will refer pain down the neck into the shoulder blade area.
The rectus femoris muscle is one of your quad muscles. It acts primarily to extend the knee but it also helps to flex the hip. This muscle is often overloaded from athletic activity, but it also can become chronically shortened from prolonged sitting. Trigger points will refer pain deep into the knee producing a deep ache felt into the joint.
the serratus anterior muscle is located on the side of the trunk. It attaches onto the ribs and the scapulae. This muscle assists in scapular motion and stability as well as assisting the movement of the ribs. Trigger points can form in this muscle due to poor shoulder posture. Once formed, these points will cause pain to be felt in the side, under the armpit, and down the inside of the arm. Once formed trigger points will not release on their own, they require a manual technique such as trigger point massage.
trigger points are well known for causing pain, but did you know that trigger points can also cause muscle weakness as well? The muscle fibers that are locked together in a trigger point cannot be used to produce muscular contractions thus weakening the entire muscle.