Muscles for MBLEx

Trapezius Muscle

• Origin: External occipital protuberance, medial third of superior nuchal line, ligamentum nuchae, spinous processes of vertebrae C7-T12

• Insertion: Lateral third of clavicle, acromion process, and upper crest of the scapular spine

• Action: Elevation, depression, retraction, or upward rotation of scapula (depending on which part of the muscle contracts); cervical extension via the upper trapezius

• Innervation: Accessory nerve (CNXI), and cervical nerves (C3,4)

Functional Sections:

• Upper Trapezius (Descending Part): Elevates and upwardly rotates the scapula; elevates the clavicle; extends the neck; laterally flexes the upper C-spine.

• Middle Trapezius (Transverse Part): Retracts or adducts the scapula (pulls toward the midline).

• Lower Trapezius (Ascending Part): Depresses and upwardly rotates the scapula.

Levator Scapula Muscle

• Origin: Posterior tubercles of the transverse processes of C1-4 vertebrae

• Insertion: Medial (vertebral) border of scapula, between the superior angle and root of the scapular spine

• Action: Elevation and downward rotation of the scapula (tilting the glenoid fossa at its lateral aspect downward). If the scapula is stabilized by surrounding muscles, it functions to laterally flex and extend the neck.

• Innervation: Dorsal scapular nerve (C5), and cervical nerves (C3,4)

Levator Scapula Clinical Conditions and Dysfunction

Dysfunction, trigger points, and hypertonicity in the levator scapula muscle frequently develop in individuals experiencing chronic stress or anxiety. Poor posture like forward head posture, structural abnormalities such as scoliosis and torticollis, and poor ergonomics can also lead to tightness and dysfunction.

Associated Clinical Conditions:

• Cervical myofascial pain

• Cervicogenic headaches

• Trigger points (especially at attachment points)

• Fibromyalgia

• Levator scapula syndrome