BMS 448 Back Muscles

Latissimus Dorsi - Origin

Origin: T7-T12 spinous processes, sacrum, thoracolumbar fascia

Latissimus Dorsi - Insertion

Insertion: Intertubercular groove

Latissimus Dorsi - Action

Action: Shoulder adduction, extension, and medial (internal) rotation

Teres Major - Origin

Origin: Inferior angle of scapula

Teres Major - Insertion

Insertion: Intertubercular groove

Teres Major - Action

Action: Shoulder adduction, extension, and medial (internal) rotation

Teres Minor - Origin

Origin: Inferior lateral border of scapula

Teres Minor - Insertion

Insertion: Greater tubercle

Teres Minor - Action

Action: External (lateral) rotation of the shoulder

Supraspinatus - Origin

Origin: Supraspinous fossa

Supraspinatus - Insertion

Insertion: Greater tubercle

Supraspinatus - Action

Action: Shoulder abduction

Infraspinatus - Origin

Origin: Infraspinous fossa

Infraspinatus - Insertion

Insertion: Greater tubercle

Infraspinatus - Action

Action: External (lateral) rotation of the shoulder

Rhomboid Major - Origin

Origin: T2-T5 spinous processes

Rhomboid Major - Insertion

Insertion: Medial border of scapula

Rhomboid Major - Action

Action: Scapular adduction

Rhomboid Minor - Origin

Origin: C7-T1 spinous processes

Rhomboid Minor - Insertion

Insertion: Medial border of scapula, superior to spine

Rhomboid Minor - Action

Action: Scapular adduction

Levator Scapulae - Origin

Origin: C1-C4 transverse processes

Levator Scapulae - Insertion

Insertion: Superior medial border of scapula

Levator Scapulae - Action

Action: Adducts and elevates scapula

Trapezius - Origin

Origin: External occipital protuberance, T1-T12 spinous processes

Trapezius - Insertion

Insertion: Lateral 3rd clavicle, acromion, and spine of scapula

Trapezius - Action

Action: Elevates, depresses, adducts, and stabilizes scapula