The levator scapula muscle adducts and downwardly (medially) rotates the scapula and is a synergist of the trapezius for adduction but an antagonist for rotation.
The levator scapula (LS) attaches to the transverse processes of the first 4 cervical vertebrae, and can restrict cervical rotation, but in the presence of excessive cervical joint flexibility may rotate the cervical spine during shoulder motions.
During shoulder flexion, the LS is stretched as the scapula upwardly rotates. If the LS is ‘stiff’ (limited extensibility) the stretch of the muscle can rotate the head to the ipsilateral (same) side.
Because this muscle attaches to the medial aspect of the superior angle of the scapula. Shortness of this muscle can limit upward rotation of the scapula and can give the impression of an elevated shoulder when observing the shoulder height near the base of the neck.
The attachment of the LS to the superior angle of the scapula can elevate the most medial portion of the scapula but does not elevate the acromial region. During shoulder flexion, the LS is stretched as the scapula upwardly rotates. The LS can elevate the most medial portion of the scapula, but does not elevate the acromial region. It is also important to differentiate between shortness of the levator scapula and rhomboids versus the upper trapezius in the treatment phase.
Action
Unilaterally
- Elevates the scapula (scapulothoracic joint)
- Downwardly rotates the scapula (scapulothoracic joint)
- Laterally flexes the head and neck
- Rotates the head and neck to the same side
Bilaterally
- Extends the head and neck
Origin
- Transverse process of the 1st through 4th cervical vertebrae
Insertion
- Medial border and superior angle of the scapula
Nerve Innervation
- Dorsal scapular nerve and cervical nerves