The insertion of the sternal head is the mastoid process of the temporal bone and the superior nuchal line of the occipital bone is the insertion of the clavicular head. It is easily seen and felt because it lies close to the skin.

The carotid pulse may be felt in the middle third of the front edge. It protects the neurovascular bundle which has the common carotid artery (medial), the internal jugular vein (lateral), the vagus nerve (dorsal), and the ansa cervicalis or also called the ansa hypoglossi (a loop of nerves that are part of the cervical plexus. This loop of nerves lies superficial to the internal jugular vein). This paired muscle is what is involved in pulling the head forward and down while it also prevents the head from tilting too far backward.

The mastoid process is located behind the ear and the rounded bump you can feel there is where the sternal attachment (that starts at the base of your throat) inserts to the head at the mastoid process. The other attachment of this muscle starts at the clavicle and its’ insertion to the head is at the occipital bone (which is at the base of the skull).