Shoulder Muscles Flashcards
Origin of the Trapezius
- Superior nuchel line/occiput
- External occipital protuberance
- Ligamentum Nuchae
- Spines of the thoracic vertebrae
Insertion of the Trapezius
- Clavicle
- Acromion process and spine/scapula
Action of the Trapezius
- Stabilizes scapula
- Upper portion: Elevates scapula
- Middle and lower portions: Adducts scapula
Nerve supply of the Trapezius
- Motor: Spinal accessory nerve (XI cranial)
- Sensory: C4 and C5
Origin of the Rhomboid Major
- Spines/Upper thoracics
Insertion of the Rhomboid Major
- Vertebral border/Scapula
Action of the Rhomboid Major
- Elevates and adducts scapula
- Helps stabilize scapula
Nerve supply of the Rhomboid Major
- Dorsal scapular nerve
Origin of the Rhomboid Minor
- Spines/Lower cervicles and T1
Insertion of the Rhomboid Minor
- Vertebral border/Scapula
Action of the Rhomboid Minor
- Elevates and adducts scapula
- Helps stabilize scapula
Nerve supply of the Rhomboid Minor
- Dorsal scapular nerve
Origin of the Levator Scapula
- Transverse process/Upper cervicals
Insertion of the Levator Scapula
- Superior border/Scapula
Action of the Levator Scapula
- Elevates scapula
- Adducts scapula
- Stabilizes scapula
Nerve supply of the Levator Scapula
- Dorsal scapula nerve
Origin of the Latissimus Dorsi
- Spines/lower thoracic and lumbar vertebrae
- Thoracadorsal fascia
- Crest/Ilium
Insertion of the Latissimus Dorsi
- Intertubercular groove/humerus
Action of the Latissimus Dorsi
- Extends, adducts, and medially rotates humerus
- Forced expiration
Nerve supply of the Latissimus Dorsi
- Thoracodorsal nerve
Origin of the Serratus Anterior
- First rib
Insertion of the Serratus Anterior
- Vertebral border/scapula
Action of the Serratus Anterior
- Abduction/protraction of the scapula
- Forced inspiration
Nerve supply of the Serratus Anterior
- Long thoracic nerve
