Scalene muscles

The scalene muscles (Latin: musculi scaleni) are three paired muscles found in the lateral compartment of the neck. Therefore, they are also known as the lateral neck muscles. The scalene muscles stretch between the transverse processes of the cervical vertebrae and the first and second ribs. These muscles include the anterior, middle and posterior scalene.

All scalene muscles have similar functions. The bilateral contractions flex the neck, while the unilateral contractions of these muscles provide neck lateral flexion to the ipsilateral side and neck rotation to the contralateral side. The only difference between the action of all scalenes is the rib that they elevate. The anterior and middle scalenes elevate the first rib, while the posterior scalene lifts the second rib.