Muscle Review: Sternocleidomastoid (SCM)
Updated: Sep 1, 2019
Turn your head to the left. Now, reach down and feel the long muscle that runs from the base of your neck to just behind your ear. Congrats! You've met one of your two Sternocleidomastoids, or SCMs!
These muscles originate from the inner most aspects of the clavicles and sternum, and extend up alongside the neck, and insert on mastoid process of the temporal bone at the skull. As one side contracts, your head will turn in the direction; likewise the opposite side extends. Often times when there is a pain or crick in one side of the the neck, there is a muscular imbalance between the two. If both left and right SCMs contract, the head is pulled or bent forward. If this becomes a postural holding pattern, pain in the back of the neck at the base and just below the base of the skull may become chronic. This is often due to repetitive motions of bringing the head forward or down (being on the computer or phone, driving, etc.) and weakened posterior neck muscles.
The SCM plays a major role in infant torticollis and displacement of a broken clavicle. The former results from positional issues with the fetus in the womb where the head is rotated and tucked, shortening the SMC. Upon birth, the SCM remains contracted, resulting in a tilted head posture. The latter happens upon a fracture or break in the clavicle, where the SCM pulls the fractured bit upward, displacing it until it reset. These conditions are rare, and require treatment from health care professionals.
To counter general pain and tightness in the SMC(s), self massage, stretching and strengthening my do the trick. However, relief and best results would be seen by working with a licensed massage or physical therapist in receiving bodywork and trigger point therapy to help release tension, while engaging in exercises for the posterior neck and SCM(s) will help strengthen and lengthen to provide support, stabilization, and proper posture. This may include chin tucks, alternate chin-to-shoulder rotations, and prone rower exercises.