Figure 1. Muscles That Position the Pectoral Girdle<\/strong><\/p>\n\n\n\n The muscles that stabilize the pectoral girdle make it a steady base on which other muscles can move the arm. Note that the pectoralis major and deltoid, which move the humerus, are cut here to show the deeper positioning muscles.<\/p>\n\n\n\n Similar to the muscles that position the pectoral girdle, muscles that cross the shoulder joint and move the humerus bone of the arm include both axial and scapular muscles (Figure 2\u00a0and\u00a0Figure 3). The two axial muscles are the pectoralis major and the latissimus dorsi. The\u00a0pectoralis major\u00a0is thick and fan-shaped, covering much of the superior portion of the anterior thorax. The broad, triangular\u00a0latissimus dorsi\u00a0is located on the inferior part of the back, where it inserts into a thick connective tissue sheath called an aponeurosis.<\/p>\n\n\n Figure 2. Muscles That Move the Humerus<\/strong><\/p>\n\n\n\n (a, c) The muscles that move the humerus anteriorly are generally located on the anterior side of the body and originate from the sternum (e.g., pectoralis major) or the anterior side of the scapula (e.g., subscapularis). (b) The muscles that move the humerus superiorly generally originate from the superior surfaces of the scapula and\/or the clavicle (e.g., deltoids). The muscles that move the humerus inferiorly generally originate from the middle or lower back (e.g., latissiumus dorsi). (d) The muscles that move the humerus posteriorly are generally located on the posterior side of the body and inserted into the scapula (e.g., infraspinatus).<\/p>\n\n\n Figure 3. Muscles That Move the Humerus<\/strong><\/p>\n\n\n\n The rest of the shoulder muscles originate on the scapula. The anatomical and ligamental structure of the shoulder joint and the arrangements of the muscles covering it, allow the arm to carry out different types of movements. The\u00a0deltoid, the thick muscle that creates the rounded lines of the shoulder is the major abductor of the arm, but it also facilitates flexing and medial rotation, as well as extension and lateral rotation. The\u00a0subscapularis\u00a0originates on the anterior scapula and medially rotates the arm. Named for their locations, the\u00a0supraspinatus\u00a0(superior to the spine of the scapula) and the\u00a0infraspinatus\u00a0(inferior to the spine of the scapula) abduct the arm and laterally rotate the arm, respectively. The thick and flat\u00a0teres major\u00a0is inferior to the teres minor extends the arm, and assists in adduction and medial rotation of it. The long\u00a0teres minor\u00a0laterally rotates and extends the arm. Finally, the\u00a0coracobrachialis\u00a0flexes and adducts the arm.<\/p>\n\n\n\n The tendons of the deep subscapularis, supraspinatus, infraspinatus, and teres minor connect the scapula to the humerus, forming the\u00a0rotator cuff\u00a0(musculotendinous cuff), the circle of tendons around the shoulder joint. When baseball pitchers undergo shoulder surgery it is usually on the rotator cuff, which becomes pinched and inflamed, and may tear away from the bone due to the repetitive motion of bringing the arm overhead to throw a fast pitch.<\/p>\n\n\n\n The forearm, made of the radius and ulna bones, has four main types of action at the hinge of the elbow joint: flexion, extension, pronation, and supination. The forearm flexors include the biceps brachii, brachialis, and brachioradialis. The extensors are the\u00a0triceps brachii\u00a0and\u00a0anconeus. The pronators are the\u00a0pronator teres\u00a0and the\u00a0pronator quadratus, and the\u00a0supinator\u00a0is the only one that turns the forearm anteriorly. When the forearm faces anteriorly, it is supinated. When the forearm faces posteriorly, it is pronated.<\/p>\n\n\n\n The biceps brachii, brachialis, and brachioradialis flex the forearm. The two-headed\u00a0biceps brachii\u00a0crosses the shoulder and elbow joints to flex the forearm, also taking part in supinating the forearm at the radioulnar joints and flexing the arm at the shoulder joint. Deep to the biceps brachii, the\u00a0brachialis\u00a0provides additional power in flexing the forearm. Finally, the\u00a0brachioradialis\u00a0can flex the forearm quickly or help lift a load slowly. These muscles and their associated blood vessels and nerves form the\u00a0anterior compartment of the arm\u00a0(anterior flexor compartment of the arm) (Figure 4\u00a0and\u00a0Figure 5).<\/p>\n\n\n Figure 4. Muscles That Move the Forearm<\/strong><\/p>\n\n\n\n The muscles originating in the upper arm flex, extend, pronate, and supinate the forearm. The muscles originating in the forearm move the wrists, hands, and fingers.<\/p>\n\n\n Figure 5. Muscles That Move the Forearm<\/strong><\/p>\n\n\n\n Wrist, hand, and finger movements are facilitated by two groups of muscles. The forearm is the origin of the\u00a0extrinsic muscles of the hand. The palm is the origin of the intrinsic muscles of the hand.<\/p>\n\n\n\n The muscles in the\u00a0anterior compartment of the forearm\u00a0(anterior flexor compartment of the forearm) originate on the humerus and are inserted into different parts of the hand. These make up the bulk of the forearm. From lateral to medial, the\u00a0superficial anterior compartment of the forearm\u00a0includes the\u00a0flexor carpi radialis,\u00a0palmaris longus,\u00a0flexor carpi ulnaris, and\u00a0flexor digitorum superficialis. The flexor digitorum superficialis flexes the hand as well as the digits at the knuckles, which allows for rapid finger movements, as in typing or playing a musical instrument (see\u00a0Figure 6\u00a0and\u00a0Table 9). However, poor ergonomics can irritate the tendons of these muscles as they slide back and forth with the carpal tunnel of the anterior wrist and pinch the median nerve, which also travels through the tunnel, causing Carpal Tunnel Syndrome. The\u00a0deep anterior compartment\u00a0produces flexion and bends fingers to make a fist. These are the\u00a0flexor pollicis longus\u00a0and the\u00a0flexor digitorum profundus.<\/p>\n\n\n\n The muscles in the\u00a0superficial posterior compartment of the forearm\u00a0(superficial posterior extensor compartment of the forearm) originate on the humerus. These are the\u00a0extensor radialis longus,\u00a0extensor carpi radialis brevis,\u00a0extensor digitorum,\u00a0extensor digiti minimi, and the\u00a0extensor carpi ulnaris.<\/p>\n\n\n\n The muscles of the\u00a0deep posterior compartment of the forearm\u00a0(deep posterior extensor compartment of the forearm) originate on the radius and ulna. These include the\u00a0abductor pollicis longus,\u00a0extensor pollicis brevis,\u00a0extensor pollicis longus, and\u00a0extensor indicis\u00a0(see\u00a0Figure 6).<\/p>\n\n\n Figure 6. Muscles That Move the Wrist, Hands, and Forearm<\/strong><\/p>\n\n\n\n The tendons of the forearm muscles attach to the wrist and extend into the hand. Fibrous bands called\u00a0retinacula\u00a0sheath the tendons at the wrist. The\u00a0flexor retinaculum\u00a0extends over the palmar surface of the hand while the\u00a0extensor retinaculum\u00a0extends over the dorsal surface of the hand.<\/p>\n\n\n\n The\u00a0intrinsic muscles of the hand\u00a0both originate and insert within it (Figure 7). These muscles allow your fingers to also make precise movements for actions, such as typing or writing. These muscles are divided into three groups. The\u00a0thenar\u00a0muscles are on the radial aspect of the palm. The\u00a0hypothenar\u00a0muscles are on the medial aspect of the palm, and the\u00a0intermediate\u00a0muscles are midpalmar.<\/p>\n\n\n\n The thenar muscles include the\u00a0abductor pollicis brevis,\u00a0opponens pollicis,\u00a0flexor pollicis brevis, and the\u00a0adductor pollicis. These muscles form the\u00a0thenar eminence, the rounded contour of the base of the thumb, and all act on the thumb. The movements of the thumb play an integral role in the most precise movements of the hand.<\/p>\n\n\n\n The hypothenar muscles include the\u00a0abductor digiti minimi,\u00a0flexor digiti minimi brevis, and the\u00a0opponens digiti minimi. These muscles form the\u00a0hypothenar eminence, the rounded contour of the little finger, and as such, they all act on the little finger. Finally, the intermediate muscles act on all the fingers and include the\u00a0lumbrical, the\u00a0palmar interossei, and the\u00a0dorsal interossei.<\/p>\n\n\n Figure 7. Intrinsic Muscles of the Hand<\/strong><\/p>\n\n\n\n The intrinsic muscles of the hand both originate and insert within the hand. These muscles provide the fine motor control of the fingers by flexing, extending, abducting, and adducting the more distal finger and thumb segments.<\/p>\n\n\n\n The clavicle and scapula make up the pectoral girdle, which provides a stable origin for the muscles that move the humerus. The muscles that position and stabilize the pectoral girdle are located on the thorax. The anterior thoracic muscles are the subclavius, pectoralis minor, and the serratus anterior. The posterior thoracic muscles are the trapezius, levator scapulae, rhomboid major, and rhomboid minor. Nine muscles cross the shoulder joint to move the humerus. The ones that originate on the axial skeleton are the pectoralis major and the latissimus dorsi. The deltoid, subscapularis, supraspinatus, infraspinatus, teres major, teres minor, and coracobrachialis originate on the scapula.<\/p>\n\n\n\n The forearm flexors include the biceps brachii, brachialis, and brachioradialis. The extensors are the triceps brachii and anconeus. The pronators are the pronator teres and the pronator quadratus. The supinator is the only one that turns the forearm anteriorly.<\/p>\n\n\n\n The extrinsic muscles of the hands originate along the forearm and are inserted into the hand to facilitate crude movements of the wrists, hands, and fingers. The superficial anterior compartment of the forearm produces flexion. These muscles are the flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and the flexor digitorum superficialis. The deep anterior compartment produces flexion as well. These are the flexor pollicis longus and the flexor digitorum profundus. The rest of the compartments produce extension. The extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris are the muscles found in the superficial posterior compartment. The deep posterior compartment includes the abductor longus, extensor pollicis brevis, extensor pollicis longus, and extensor indicis.<\/p>\n\n\n\n Finally, the intrinsic muscles of the hands allow our fingers to make precise movements, such as typing and writing. They both originate and insert within the hand. The thenar muscles, which are located on the lateral part of the palm, are the abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, and adductor pollicis. The hypothenar muscles, which are located on the medial part of the palm, are the abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi. The intermediate muscles, located in the middle of the palm, are the lumbricals, palmar interossei, and dorsal interossei. abductor digiti minimi<\/strong><\/p>\n\n\n\n the muscle that abducts the little finger<\/p>\n\n\n\n adductor pollicis<\/strong><\/p>\n\n\n\n the muscle that adducts the thumb<\/p>\n\n\n\n abductor pollicis brevis<\/strong><\/p>\n\n\n\n the muscle that abducts the thumb<\/p>\n\n\n\n abductor pollicis longus<\/strong><\/p>\n\n\n\n muscle that inserts into the first metacarpal<\/p>\n\n\n\n anconeus<\/strong><\/p>\n\n\n\n small muscle on the lateral posterior elbow that extends the forearm<\/p>\n\n\n\n anterior compartment of the arm<\/strong><\/p>\n\n\n\n (anterior flexor compartment of the arm) the biceps brachii, brachialis, brachioradialis, and their associated blood vessels and nerves<\/p>\n\n\n\n anterior compartment of the forearm<\/strong><\/p>\n\n\n\n (anterior flexor compartment of the forearm) deep and superficial muscles that originate on the humerus and are inserted into the hand<\/p>\n\n\n\n biceps brachii<\/strong><\/p>\n\n\n\n two-headed muscle that crosses the shoulder and elbow joints to flex the forearm while assisting in supinating it and flexing the arm at the shoulder<\/p>\n\n\n\n brachialis<\/strong><\/p>\n\n\n\n muscle deep to the biceps brachii that provides power in flexing the forearm.<\/p>\n\n\n\n brachioradialis<\/strong><\/p>\n\n\n\n muscle that can flex the forearm quickly or help lift a load slowly<\/p>\n\n\n\n coracobrachialis<\/strong><\/p>\n\n\n\n muscle that flexes and adducts the arm<\/p>\n\n\n\n deep anterior compartment<\/strong><\/p>\n\n\n\n flexor pollicis longus, flexor digitorum profundus, and their associated blood vessels and nerves<\/p>\n\n\n\n deep posterior compartment of the forearm<\/strong><\/p>\n\n\n\n (deep posterior extensor compartment of the forearm) the abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis, and their associated blood vessels and nerves<\/p>\n\n\n\n deltoid<\/strong><\/p>\n\n\n\n shoulder muscle that abducts the arm as well as flexes and medially rotates it, and extends and laterally rotates it<\/p>\n\n\n\n dorsal interossei<\/strong><\/p>\n\n\n\n muscles that abduct and flex the three middle fingers at the metacarpophalangeal joints and extend them at the interphalangeal joints<\/p>\n\n\n\n extensor carpi radialis brevis<\/strong><\/p>\n\n\n\n muscle that extends and abducts the hand at the wrist<\/p>\n\n\n\n extensor carpi ulnaris<\/strong><\/p>\n\n\n\n muscle that extends and adducts the hand<\/p>\n\n\n\n extensor digiti minimi<\/strong><\/p>\n\n\n\n the muscle that extends the little finger<\/p>\n\n\n\n extensor digitorum<\/strong><\/p>\n\n\n\n muscle that extends the hand at the wrist and the phalanges<\/p>\n\n\n\n extensor indicis<\/strong><\/p>\n\n\n\n muscle that inserts onto the tendon of the extensor digitorum of the index finger<\/p>\n\n\n\n extensor pollicis brevis<\/strong><\/p>\n\n\n\n muscle that inserts onto the base of the proximal phalanx of the thumb<\/p>\n\n\n\n extensor pollicis longus<\/strong><\/p>\n\n\n\n muscle that inserts onto the base of the distal phalanx of the thumb<\/p>\n\n\n\n extensor radialis longus<\/strong><\/p>\n\n\n\n muscle that extends and abducts the hand at the wrist<\/p>\n\n\n\n extensor retinaculum<\/strong><\/p>\n\n\n\n band of connective tissue that extends over the dorsal surface of the hand<\/p>\n\n\n\n extrinsic muscles of the hand<\/strong><\/p>\n\n\n\n muscles that move the wrists, hands, and fingers and originate in the arm<\/p>\n\n\n\n flexor carpi radialis<\/strong><\/p>\n\n\n\n muscle that flexes and abducts the hand at the wrist<\/p>\n\n\n\n flexor carpi ulnaris<\/strong><\/p>\n\n\n\n muscle that flexes and adducts the hand at the wrist<\/p>\n\n\n\n flexor digiti minimi brevis<\/strong><\/p>\n\n\n\n muscle that flexes the little finger<\/p>\n\n\n\n flexor digitorum profundus<\/strong><\/p>\n\n\n\n muscle that flexes the phalanges of the fingers and the hand at the wrist<\/p>\n\n\n\n flexor digitorum superficialis<\/strong><\/p>\n\n\n\n muscle that flexes the hand and the digits<\/p>\n\n\n\n flexor pollicis brevis<\/strong><\/p>\n\n\n\n muscle that flexes the thumb<\/p>\n\n\n\n flexor pollicis longus<\/strong><\/p>\n\n\n\n muscle that flexes the distal phalanx of the thumb<\/p>\n\n\n\n flexor retinaculum<\/strong><\/p>\n\n\n\n band of connective tissue that extends over the palmar surface of the hand<\/p>\n\n\n\n hypothenar<\/strong><\/p>\n\n\n\n group of muscles on the medial aspect of the palm<\/p>\n\n\n\n hypothenar eminence<\/strong><\/p>\n\n\n\n rounded contour of muscle at the base of the little finger<\/p>\n\n\n\n infraspinatus<\/strong><\/p>\n\n\n\n the muscle that laterally rotates the arm<\/p>\n\n\n\n intermediate<\/strong><\/p>\n\n\n\n group of midpalmar muscles<\/p>\n\n\n\n intrinsic muscles of the hand<\/strong><\/p>\n\n\n\n muscles that move the wrists, hands, and fingers and originate in the palm<\/p>\n\n\n\n latissimus dorsi<\/strong><\/p>\n\n\n\n broad, triangular axial muscle located on the inferior part of the back<\/p>\n\n\n\n lumbrical<\/strong><\/p>\n\n\n\n muscle that flexes each finger at the metacarpophalangeal joints and extends each finger at the interphalangeal joints<\/p>\n\n\n\n opponens digiti minimi<\/strong><\/p>\n\n\n\n muscle that brings the little finger across the palm to meet the thumb<\/p>\n\n\n\n opponens pollicis<\/strong><\/p>\n\n\n\n muscle that moves the thumb across the palm to meet another finger<\/p>\n\n\n\n palmar interossei<\/strong><\/p>\n\n\n\n muscles that abduct and flex each finger at the metacarpophalangeal joints and extend each finger at the interphalangeal joints<\/p>\n\n\n\n palmaris longus<\/strong><\/p>\n\n\n\n muscle that provides weak flexion of the hand at the wrist<\/p>\n\n\n\n pectoral girdle<\/strong><\/p>\n\n\n\n shoulder girdle, made up of the clavicle and scapula<\/p>\n\n\n\n pectoralis major<\/strong><\/p>\n\n\n\n thick, fan-shaped axial muscle that covers much of the superior thorax<\/p>\n\n\n\n pectoralis minor<\/strong><\/p>\n\n\n\n muscle that moves the scapula and assists in inhalation<\/p>\n\n\n\n pronator quadratus<\/strong><\/p>\n\n\n\n pronator that originates on the ulna and inserts on the radius<\/p>\n\n\n\n pronator teres<\/strong><\/p>\n\n\n\n pronator that originates on the humerus and inserts on the radius<\/p>\n\n\n\n retinacula<\/strong><\/p>\n\n\n\n fibrous bands that sheath the tendons at the wrist<\/p>\n\n\n\n rhomboid major<\/strong><\/p>\n\n\n\n muscle that attaches the vertebral border of the scapula to the spinous process of the thoracic vertebrae<\/p>\n\n\n\n rhomboid minor<\/strong><\/p>\n\n\n\n muscle that attaches the vertebral border of the scapula to the spinous process of the thoracic vertebrae<\/p>\n\n\n\n rotator cuff<\/strong><\/p>\n\n\n\n (also, musculotendinous cuff) the circle of tendons around the shoulder joint<\/p>\n\n\n\n serratus anterior<\/strong><\/p>\n\n\n\n large and flat muscle that originates on the ribs and inserts into the scapula<\/p>\n\n\n\n subclavius<\/strong><\/p>\n\n\n\n muscle that stabilizes the clavicle during movement<\/p>\n\n\n\n subscapularis<\/strong><\/p>\n\n\n\n muscle that originates on the anterior scapula and medially rotates the arm<\/p>\n\n\n\n superficial anterior compartment of the forearm<\/strong><\/p>\n\n\n\n flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, and their associated blood vessels and nerves<\/p>\n\n\n\n superficial posterior compartment of the forearm<\/strong><\/p>\n\n\n\n extensor radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, and their associated blood vessels and nerves<\/p>\n\n\n\n supinator<\/strong><\/p>\n\n\n\n muscle that moves the palm and forearm anteriorly<\/p>\n\n\n\n supraspinatus<\/strong><\/p>\n\n\n\n the muscle that abducts the arm<\/p>\n\n\n\n teres major<\/strong><\/p>\n\n\n\n the muscle that extends the arm and assists in adduction and medial rotation of it<\/p>\n\n\n\n teres minor<\/strong><\/p>\n\n\n\n muscle that laterally rotates and extends the arm<\/p>\n\n\n\n thenar<\/strong><\/p>\n\n\n\n group of muscles on the lateral aspect of the palm<\/p>\n\n\n\n thenar eminence<\/strong><\/p>\n\n\n\n rounded contour of muscle at the base of the thumb<\/p>\n\n\n\n trapezius<\/strong><\/p>\n\n\n\n muscle that stabilizes the upper part of the back<\/p>\n\n\n\n triceps brachii<\/strong><\/p>\n\n\n\n three-headed muscle that extends the forearm There are many exercises you can do on the cable machine that target the muscles in your upper body. Two of the more popular exercises that target the chest, shoulders, and triceps are the standing shoulder press and the cable chest fly.\u00a0<\/p>\n\n\n\nMuscles that Move the Humerus<\/h2>\n\n\n\n
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Muscles that Move the Forearm<\/h2>\n\n\n\n
Muscles that Move the Wrist, Hand & Fingers<\/h2>\n\n\n\n
Muscles of the Arm that Move the Wrists, Hands & Fingers<\/h2>\n\n\n\n
Intrinsic Muscles of the Hand<\/h2>\n\n\n\n
REVIEW<\/h2>\n\n\n\n
<\/p>\n\n\n\nGLOSSARY<\/h2>\n\n\n\n
<\/p>\n\n\n\nBodyFly Upper Body Exercises<\/h2>\n\n\n\n
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