Sternocleidomastoid

The primary functions of the sternocleidomastoid muscle are to facilitate head movement and assist in the stabilization of the head during dynamic activities. When both muscles contract simultaneously, they flex the neck, allowing the chin to move toward the chest. In contrast, when only one muscle contracts, it enables the head to rotate toward the opposite side while tilting toward the same side. This muscle is vital for various activities, such as turning the head while driving, maintaining posture, and engaging in sports that require neck mobility. Additionally, the sternocleidomastoid plays a role in respiration by aiding with inhalation when the head is fixed, particularly during strenuous activities. Its dual action not only contributes to everyday movements but also enhances balance and coordination.

The sternocleidomastoid muscles are located in the anterior part of the neck, extending from the sternum and clavicle to the mastoid process of the temporal bone. The muscle is prominently displayed on either side of the neck, creating a distinct contour. When the head is turned, the muscle becomes more pronounced, making it easily identifiable beneath the skin. Its strategic positioning allows it to connect the upper body to the skull, facilitating a wide range of head movements while providing necessary support to the cervical spine.

• The name sternocleidomastoid is derived from its points of attachment: 'sterno' refers to the sternum, 'cleido' refers to the clavicle, and 'mastoid' refers to the mastoid process of the skull.
• This muscle is often used in clinical assessments to check for neck tension or injury.
• The sternocleidomastoid can also contribute to neck pain if overused or strained.
• In yoga and similar practices, stretching this muscle can enhance flexibility and reduce tension in the neck area.