The sternocleidomastoid muscle, commonly referred to as the neck muscle, is a paired muscle located in the front of the neck. It originates from the sternum and clavicle and inserts into the mastoid process of the skull. This muscle is responsible for various movements of the head, including rotating the head to the opposite side and flexing the neck. It also assists in elevating the sternum during deep inhalation. Additionally, the sternocleidomastoid muscle is important for maintaining proper posture and stabilizing the head and neck during activities such as running and weightlifting.

The sternocleidomastoid muscle, commonly referred to as the neck muscle, is a paired muscle located in the front of the neck. It originates from the sternum and clavicle and inserts into the mastoid process of the skull. This muscle is responsible for various movements of the head, including rotating the head to the opposite side and flexing the neck. It also assists in elevating the sternum during deep inhalation. Additionally, the sternocleidomastoid muscle is important for maintaining proper posture and stabilizing the head and neck during activities such as running and weightlifting.