Muscle Breakdown: Sternocleidomastoid
Table of Contents
What Is the Sternocleidomastoid
Have you ever wondered how your head can move in so many different directions? The Sternocleidomastoid is a large muscle in the neck that is responsible for many movements of the head. It is a superficial muscle that you can see and feel in the neck.
Sternocleidomastoid Muscle & Cadaver
Sternocleidomastoid Location
The Sternocleidomastoid is a bilateral muscle, meaning that there is a Sternocleidomastoid on either side of the neck. Each Sternocleidomastoid has two muscle heads that each have a different point of origin.
Sternocleidomastoid Function
As previously mentioned, the Sternocleidomastoid allows the head to move in many different ways! Since the Sternocleidomastoid is a bilateral muscle, both Sternocleidomastoids can work together to produce movement, or they can work alone. The Sternocleidomastoid functions to produce the following movements,
Contralateral rotation of the Neck
Ipsilateral flexion of the Neck
Extension of the Head and the Neck
Flexion of the Cervical Spine
Elevates the Clavicle
In layman’s terms, this means that the Sternocleidomastoid functions to rotate your head to one side or the other, bring the ear towards the shoulder, look up towards the sky and bring the chin down to your chest.
Sternocleidomastoid Origin And Insertion
Sternocleidomastoid Origin
The Sternocleidomastoid is a two-headed muscle. It has a Sternal Head and a Clavicular head. The Sternal head of the Sternocleidomastoid originates from the superior part of the manubrium. The Clavicular head of the Sternocleidomastoid originates from the medial third of the Clavicle.
Sternocleidomastoid Insertion
The Sternocleidomastoid inserts into the lateral part of the Mastoid Process and the lateral half of the superior Nuchal Line of the Occipital bone.
Sternocleidomastoid Innervation
The Sternocleidomastoid is innervated by the Accessory nerve.
Sternocleidomastoid Pain
As you can tell, the Sternocleidomastoid is an important muscle to the Head and the Neck. As such, pain in the Sternocleidomastoid can arise from many different sources. In today’s society, experiencing pain in the Sternocleidomastoid can be a result of looking down at your phone or hunching forwards when typing on your computer. These activities can cause the Sternocleidomastoid to become tight and short, resulting in pain.
Additional sources of pain in the Sternocleidomastoid can be the result of disease, injury or repetitive work. For example, Bronchitis, Whiplash, poor posture or looking up for work all day (such as with painting or construction) can all cause pain in the Sternocleidomastoid.
Symptoms of pain in the Sternocleidomastoid include,
Muscle fatigue
Pain in the neck, jaw or ear
Ringing in the ear
Difficulty holding the head up
Stiffness of the neck
Headaches
Dizziness or imbalance
Watery eyes
Sternocleidomastoid Syndrome
Many muscles of the body have trigger points. These are points in the muscle where the muscle fibers form bands that can become very sensitive when irritated. Sternocleidomastoid Syndrome is when the trigger points of the Sternocleidomastoid become irritated and you may experience pain, a loss of range of motion of the neck, and stiffness of the muscle.
Sternocleidomastoid Syndrome can be caused by stress, poor posture and overuse of the muscle. Often, Sternocleidomastoid Syndrome can cause pain in other areas of the body that are trying to make up for the tightness of the muscle such as in the shoulders, eyes, throat, behind the head and neck.
Treatment for Sternocleidomastoid Syndrome can vary depending on the cause. Often, Physical Therapy will be required where various stretches and exercises will be prescribed to help reduce the pain and stiffness of the Sternocleidomastoid. Massage can also be helpful to reduce pain and relax the muscle. If stress is the source of your Sternocleidomastoid Syndrome, activities such as mediation, yoga and general relaxation may be beneficial.
Sternocleidomastoid Exercise
Neck Rotations
Keep the shoulders relaxed, and down and back. Breathe out, and slowly turn your head towards your left side. Breathe in and return your head to the center. Repeat this movement for 10 rotations to both sides of the neck.
Head Tilts
Similar to the Neck Rotations, begin with your head facing forwards at the center. Breathe out, and bring your ear towards your shoulder on one side. Hold this position for two breaths, and then return to the center. Repeat this
Sternocleidomastoid Stretch
Side Stretch
Use one hand to place your fingers on the base of the Sternocleidomastoid muscle on the same side of the body. Gently use the other hand to pull your head towards the opposite side of the body, bringing the ear towards the shoulder. Next, look up towards the ceiling and extend the head back a little bit. Hold this position for 30 seconds and then switch sides.
