Using the Muscle Charts: Students should be able to identify all muscles listed on the daily lab pages. In addition to identification you will be required to know more information about some muscle and muscle groups. Use the key below as a guide. Any box on the muscle chart requires you to know all the information (e.g. action, origin, insertion and innervation) provided. Areas shaded in green require muscle identification and a general sense of the location of the origin or insertion. (e.g. knowing that the rhomboids originate on the vertebrae, as opposed to the specific numbered vertebrae).
Muscles that Move the Pectoral Girdle and Stabilize the Scapula
Group/Muscle Actions Origin Insertion Innervation
Superior fibers: Elevate and Occipital bone, cervical Clavicle; acromion superiorly rotate scapula Accessory nerve Trapezius and thoracic spinous process and spine of Middle fibers: Retract scapula (CN XI) processes scapula Inferior fibers: Depress scapula Elevates and inferiorly rotates Upper cervical transverse Superior medial border Levator scapulae scapula processes of scapula Spinous processes of T2– Medial border of Dorsal scapular Rhomboid major Elevates, retracts, and inferiorly T5 scapula nerve rotates scapula Spinous processes of C7– Superior medial border Rhomboid minor T1 of scapula Coracoid process of Medial pectoral Pectoralis minor Protracts and depresses scapula Ribs 3–5 scapula nerve Protracts and superiorly rotates Anterior medial border Long thoracic Serratus anterior Ribs 1–8 scapula; stabilizes scapula of scapula nerve Inferior surface of Nerve to Subclavius Stabilizes and depresses clavicle Rib 1 clavicle subclavius
Muscles that Act on the Glenohumeral Joint to Move the Arm Muscle Actions Origin Insertion Innervation Lower thoracic spinous Extends, adducts & medially rotates Thoracodorsal Latissimus dorsi processes, lower ribs & GH joint (“swimmer’s muscle”) nerve iliac crest Intertubercular groove of humerus Lateral pectoral Arm flexion; adducts and medially Medial clavicle, superior Pectoralis major and medial rotates GH joint ribs, & body of sternum pectoral nerves Anterior fibers: Flex and medially rotate GH joint Acromial end of clavicle; Deltoid tuberosity of Deltoid Middle fibers: GH abduction acromion and spine of Axillary nerve humerus Posterior fibers: Extend and laterally scapula rotate GH Joint Middle medial shaft of Musculocutaneous Coracobrachialis Adducts and flexes GH joint Coracoid process humerus nerve Lesser tubercle and Extends, adducts, and medially Inferior lateral border and Lower subscapular Teres major intertubercular groove rotates GH joint inferior angle of scapula nerve of humerus *Triceps brachii Extends GH joint Infraglenoid tubercle Olecranon process Radial nerve Radial tuberosity and Musculocutaneous *Biceps brachii Flexes GH joint Supraglenoid tubercle bicipital aponeurosis nerve Medially rotates GH joint, Lesser tubercle of Upper and lower Subscapularis Subscapular fossa Stabilizes the GH joint humerus subscapular nerves Abducts GH joint, Stabilizes the GH Rotator Supraspinatus Supraspinous fossa joint Suprascapular cuff Greater tubercle of nerve muscles Infraspinatus Infraspinous fossa Adducts & laterally rotates GH joint, humerus Stabilize the GH joint Superior lateral border of Teres minor Axillary nerve scapula *These muscles also act on the elbow, but only actions on the GH joint are shown here.