Term | Definition |
Supraspinatus | Origin: Supraspinous Fossa
Insertion: Greater Tubercle of Humerus
Innervation: Suprascapular Nerve
Action: Initiates 15 degrees of abduction |
Infraspinatus | Origin: Infraspinous Fossa
Insertion: Greater Tubercle
Innervation: Suprascapular Nerve
Action: Medial rotation of arm |
Teres Minor | Origin: Infraspinous Fossa
Insertion: Greater tubercle of humerus
Innervation: Axillary Nerve
Action: Medial rotation of arm |
Subscapularis | Origin: Subscapular Fossa
Insertion: Lesser tubercle of humerus
Innervation: Upper and lower subscapular nerves
Action: Medial rotation of scapula |
Teres Major | Origin: Inferior angle of scapula
Insertion: Bicipital groove
Action: Medial rotation and adduction of arm
Innervation: Lower subscapular nerve |
Deltoids | Origin: spine of scapula and clavicle
Insertion: Deltoid tuberosity
Innervation: Axillary Nrve
Action: arm abduction, medial/lateral rotation, extension/flexion |
Levator Scapulae | Origin: T processes of C1-C4
Insertion: Superior angle of scapula
Action: Elevates scapula
Innervation: Dorsal scapular nerve |
Rhomboid Minor | Origin: S processes of C7-T1
Insertion: Medial border of scapula
Action: Retraction of Scapula
Innervation: Dorsal scapular nerve |
Rhomboid Major | Origin: S processes of T2-T5
Insertion: Medial border of scapula
Action: retraction of Scapula
Innervation: Dorsal scapular nerve |
Trapezius | Origin: external occipital protruberance, S processes of C2-T12, ligamentum nuchae
Insertion: clavicle and spine of scapula
Action: elevation and retraction of scapula
Innervation: Spinal Accessory nerve |
Latissimus Dorsi | Origin: S processes of T6-L5
Insertion: Bicipital groove
Action: arm extension, adduction, medial rotation
Innervation: thoracodorsal nerve |
Pectoralis Major | Origin: sternum, clavicle, lower ribs
Insertion: Bicipital Groove
Action: arm adduction, flexion, medial rotation
Innervation: medial and lateral pectoral nerves |
Pectoralis Minor | Origin: Ribs 5, 6, 7
Insertion: Coracoid process of scapula
Action: depresses and stabilizes scapula
Innervation: Medial pectoral nerve |
Serratus Anterior | Origin: outer surface of 8 upper ribs
Insertion: medial border of scapula
Action: protraction and upward rotation of scapula
Innervation: long thoracic nerve |