National Associaltion of Myofascial Trigger Point Therapists - Symptom Checker

Sternocleidomastoid (SCM)
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This is the technical name of the muscle being described.  This name may be used to find additional information in any medical resource. Sternocleidomastoid (SCM)
A group of muscles generally denotes muscles of the same function and may share a common attachment point.  
Muscle function, in this definition, is what the muscle could do if it was to contract by itself with the body in anatomical position.  This is a general definition of muscle function.  For more information on how muscles work together on the body please refer to a physiology or functional anatomy text.

The SCM has two heads, the sternal head and claviculuar head, and a common attachment on the mastoid process of the temporal bone of the cranium.
The function of the SCM, when acting by itself, is to rotate the head to the opposite side and tilt the head up.  Together the SCM muscles will flex the head and neck and pull the head forward.

A description of where a Myofascial Trigger Point may produce pain in the body.  This area is generally located away from the trigger point.

The sternal division of the SCM is capable of harboring TrPs along the length of its fibers.  TrPs in the area around the sternum refer pain over that area.  TrPs in the middle of the muscle refer to the cheek on the same side in finger like
projections that may extend into the maxilla.  The TrPs near the
mastoid process refer pain to the occipital ridge in the back of  the head, and the vertex (top of the head) like a skull cap and above the eyebrow.  There may be scalp irritation in this area as well.

Autonomic concomitants of TrPs in the sternal division of the SCM relate to the eyes and nose on the same side.  The eyes may excessively lacrimate (tear) and cause them to appear “watery”.  Also ptosis (narrowing of the eye -- one eye looks more closed than the other) is a possibility.  Visual disturbances may occur as a blurring of vision or a dimming of perceived light.  Deafness on one side may also occur as a result of TrPs.

The clavicular division of the SCM refers pain to the frontal area
of the forehead and may also extend across.  The upper aspect of the clavicular division can refer pain deep into the ear and the posterior auricular region.  They may refer pain into the cheek and molar teeth in some cases.

Autonomic concomitants of TrPs in the clavicular division of the SCM relate to spatial orientation.  A person may complain of a postural dizziness or disorientation, and less of vertigo, which is the sensation of objects spinning around the person or of the person spinning.  The dizziness is usually activated by a sudden turning of the head and may last from seconds to hours.  Ataxia, which is veering off to one side while walking, is common.  Dysmetria, disturbed weight perception, may also occur as a result of TrPs in the clavicular SCM.  Stimulation of TrPs in the clavicular division may also refer autonomic phenomena of localized sweating and vasoconstriction, which appears in the form of blanching and thermographic cooling in the frontal area of the forehead.

A description of the symptoms a person may experience with trigger points in the muscle being described.

A person with TrPs in the SCM is likely to complain of varying and puzzling symptoms that may range from an intense headache to the feeling of dizziness and unexplained lacrimation (tears).  Neck pain and stiffness are not generally a complaint.  A person may, however, complain of soreness  over the muscle themselves.

If TrPs in the SCM are active they may cause the head to tilt to that side because to hold the head upright would induce pain.
  “Tension Headache” is a common diagnosis that is made in
patients with myofascial pain syndrome of the SCM.  Although
the pupils react normally, blurred or possibly double vision is
sometimes reported.

Pain from the sternal division may involve the cheek, temple, and orbit.  The autonomic consideration is excessive tearing
from and eye.  A common visual disturbance a person may
experience is when looking at contrasting parallel lines such as
a Venetian blind. 

A person demonstrating symptoms of the clavicular SCM will most likely show one of three symptoms, namely frontal
headache, postural dizziness or imbalance, and dysmetria
(disturbed weight perception).


 A list of possible diseases that fit the information derived from examination of a patient.

  1. Atypical cervical neuralgia.
  2. Meniere’s disease.
  3. Tic douloureux.
  4. Congenital and spasmodic torticollis.
  5. Vascular headache.
  6. Arthritis of the sternoclavicular (S/C) joint.

A list of activities or positions that may either CAUSE a trigger point to manifest or PROLONG a pain condition respectively.

  1. Head forward posture or any activity that holds the head in a forward position.
  2. Sitting with the head turned to one side for prolonged periods of time.
  3. Sleeping on the back with too much support where the head is flexed.
  4. Neck extension in overhead work such as painting a ceiling, writing higher than eye level on a blackboard, hanging curtains, sitting in the front of a movie theatre.
  5. Limping, along with abnormal gait (walking) in the push off phase, will activate TrPs in the SCM and scalenes because these muscles contract quickly in order to keep the body balanced while walking.
  6. A tight pectoralis major may activate/perpetuate SCM TrPs because of its influence on the clavicle by pulling down and forward.
  7. Tight shirt collar and tie.
  8. Hauling and pulling of horses.

A corrective action is usually a modification of daily routine which will reduce stress on the affected muscle(s) in a person with myofascial trigger points.

  1. Head forward posture must be corrected. 
  2. A chair may need altered or replaced if the headrest pushes the head forward.
  3. Face the body and the head in the same direction while viewing presentations or movies.
  4. Employment of a headset when using the phone will remove excessive strain from the levator and free up the hands to complete work more efficiently.  A speaker phone will work as well.
  5. Use a scarf to keep the neck warm in cold climates or in places prone to drafts, including airplanes.
  6. Limit neck extension, as when working or painting overhead.
  7. Avoid tight shirt collars and ties.  A finger should easily fit between the shirt collar and the neck.

References : 
Simons DG, Travell JG, Simons LS, Myofascial Pain and Dysfunction: The Trigger Point Manual, vol 1, 2nd Ed. Baltimore: Williams and Wilkins, 1999.

Travell JG, Simons DG, Myofascial Pain and Dysfunction, vol 2. Baltimore: Williams & Wilkins, 1992.

This information is not intended to diagnose, treat, or cure any disease.  A proper diagnosis should be sought from a licensed health care provider.