Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 1 of 18 Movements of the Upper Limb - Introduction This module presents the nomenclature of movement at the joints of the upper limb. When you first approach the upper limb, concentrate on the motions and less on the names of muscles producing those motions. After your study of the upper limb, use this module to review and summarize muscle actions in the upper limb. The upper limb is our primary tool for manipulating the environment, and therefore it is highly mobile. There is a great number of joints within the entire upper limb, allowing for this great mobility. In comparing the upper and lower limbs, it is evident that the upper limb is specialized as the organ of manipulation, and the lower limb serves for locomotion. To serve these purposes, the upper limb emphasizes mobility and sacrifices stability, while the lower limb emphasizes stability and sacrifices mobility. The contrast is perhaps most striking when comparing the mobile pectoral girdle (clavicles and scapulae) to the rigid pelvic girdle (os coxae and sacrum). Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 2 of 18 Scapular Protraction and Retraction Protraction of the scapula is sometimes called abduction of the scapula. The scapula is moved laterally and anteriorly along the chest wall. Muscles: serratus anterior is the prime mover. Pectoralis minor and major, the latter acting through the humerus, may assist (act as synergists). Retraction of the scapula is sometimes called adduction of the scapula. The scapula is moved posteriorly and medially along the chest wall. Muscles: rhomboideus major, minor, and trapezius are the prime movers. The muscles that protract and retract the scapula are antagonistic, that is, they have opposed actions. Used together, they fix the scapula in space to provide a fulcrum from which to move the (lever) arm. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 3 of 18 Scapular Elevation and Depression Elevation of the scapula moves the scapula superiorly. It is not synonymous with upward rotation of the scapula Muscles: levator scapulae and the upper fibers of trapezius. Depression of the scapula moves the scapula inferiorly. It is not synonymous with downward rotation of the scapula. Muscles: pectoralis minor, the lower fibers of trapezius, subclavius (through clavicle), and latissimus dorsi (through the humerus). Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 4 of 18 Scapular Upward and Downward Rotation The scapula can pivot on its attachment to the clavicle, and rotate upward. This is also called upward rotation of the glenoid fossa, and it is an essential motion for completing abduction of the arm. Muscles: trapezius and serratus anterior are synergists. When the arm is fully abducted, downward rotation of the scapula (or glenoid fossa) occurs first in adduction of the arm. Muscles: pectoralis minor and major (through humerus), subclavius, and latissimus dorsi (through the humerus). Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 5 of 18 Arm Abduction Abduction of the arm is also called abduction of/at the shoulder. This motion actually can be divided into two motions: true abduction of the arm at the shoulder and upward rotation of the scapula. Muscles: supraspinatus (initiates abduction - first 15 degrees), deltoid (up to 90 degrees), trapezius and serratus anterior (scapular rotation, for abduction beyond 90 degrees). The deltoid muscle abducts the arm, but at 90 degrees the humerus bumps into the acromion. Beyond this point, further abduction is the result of upward scapular rotation. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 6 of 18 Arm Adduction Adduction of the arm is also called adduction of/at the shoulder. This motion can be divided into two motions: downward rotation of the scapula and true adduction of the arm at the shoulder. Muscles: pectoralis major and minor, latissimus dorsi, teres major, gravity (depending on body position), and even the lowest fibers of the deltoid (making deltoid its own antagonist) Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 7 of 18 Arm Flexion and Extension Flexion of the arm is also called flexion of/ at the shoulder. It is typically thought of as an anterior excursion of the arm, but remember that any motion away from full extension is flexion. Muscles: pectoralis major, coracobrachialis, biceps brachii, anterior fibers of deltoid. Extension of the arm is also called extension of/at the shoulder. It is typically thought of as movement of the arm posteriorly, but remember that any motion away from full flexion is extension. Muscles: latissimus dorsi and teres major, long head of triceps, posterior fibers of the deltoid. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 8 of 18 Arm Medial and Lateral Rotation Medial rotation of the arm or humerus can best be seen when the elbow is flexed and the hand is moved toward the midline. Muscles: subscapularis, latissimus dorsi, teres major, pectoralis major, anterior fibers of deltoid. With the elbow flexed, lateral rotation moves the hand away from the midline. Muscles: infraspinatus and teres minor, posterior fibers of deltoid. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 9 of 18 Arm Circumduction Circumduction at a joint is a motion that circumscribes a cone. The shoulder, being the most mobile joint in the body, can circumscribe the largest cone. Muscles: pectoralis major, subscapularis, coracobrachialis, biceps brachii, supraspinatus, deltoid, latissimus dorsi, teres major and minor, infraspinatus, long head of triceps. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 10 of 18 Forearm Flexion and Extension Flexion of the forearm is also known as elbow flexion. Muscles: biceps brachii, brachialis, and brachioradialis. Extension of the forearm is also called elbow extension. Muscles: triceps brachii and anconeus. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 11 of 18 Hand Supination and Pronation Supination of the hand brings the palm to face forward in the anatomical position. It is the position you would place your hand in order to hold "soup". Muscles: biceps brachii and supinator. Brachioradialis can return the pronated hand to a position mid-way between supination and pronation. Pronation of the hand brings the palm to face posteriorly in the anatomical position, or face down when lying down. Muscles: pronator teres and pronator quadratus. Brachioradialis can return the supinated hand to a position mid-way between supination and pronation. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 12 of 18 Wrist Flexion and Extension Flexion at the wrist might also be called flexion of the hand, but it usually isn't. Muscles: all of the flexor muscles crossing the wrist joint, but especially the flexor carpi radialis and flexor carpi ulnaris. Extension at the wrist might also be called extension of the hand, but it usually isn't. Muscles: all of the extensor muscles that cross the wrist joint, but especially the extensor carpi radialis longus and brevis and the extensor carpi ulnaris. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 13 of 18 Wrist Abduction and Adduction Abduction at the wrist is also called radial deviation of the hand, because the hand moves toward the radius, or laterally. Muscles: flexor carpi radialis and extensor carpi radialis longus and brevis. Adduction at the wrist is also called ulnar deviation of the hand, because the hand moves medially toward the ulna. Muscles: flexor and extensor carpi ulnaris. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 14 of 18 Finger Abduction and Adduction Abduction of the digits of the hand is defined as moving away from the midline of the hand, which is the middle digit. Abduction, then, spreads the fingers. Muscles: dorsal interossei. Adduction of the fingers returns them toward the midline, or the middle finger. This brings the fingers together. Muscles: palmar interossei. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 15 of 18 Thumb Abduction and Adduction The thumb is set at an angle to the plane of the other four digits, so that thumb abduction brings it slightly palmar as it moves away from the middle finger. Muscles: abductor pollicis longus and brevis. The plane of abduction/adduction of the thumb is at an angle to the other digits, but thumb adduction returns the thumb to a position beside the second digit, and toward the third finger. Muscles: adductor pollicis. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 16 of 18 Opposition Opposition is the motion of both thumb and little finger that bring their tips to touch. Opposition is a fairly complex movement involving multiple muscles. The thumb is first abducted, and then flexed while the metacarpal is pulled toward the fifth digit. Muscles: abductor pollicis longus and brevis, opponens pollicis and opponens digiti minimi, flexor pollicis longus and flexor digitorum profundus. Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 17 of 18 Finger flexion and extension The four fingers have 3 different joints at which they can flex or extend - the metacarpophalangeal (MP) joint, the proximal interphalangeal (PIP) joint, and the distal interphalangeal (DIP) joint. Some muscles may flex one of these while extending the other two, or flex two and have no effect on the third. Muscles: interossei and lumbricals flex the MP while extending the PIP and DIP joints; flexor digitorum superficialis flexes the MP and PIP joints only, while flexor digitorum profundus flexes all three, and is the only muscle capable of flexing the DIP joint. Extension of the fingers occurs at the same 3 joints, but there is no muscle that extends only the DIP joint. Muscles: interossei and lumbricals extend the PIP and DIP joints while flexing the MP joint; extensor digitorum (communis) extends all 3 joints for all 4 digits, although due to tendinous connections between adjacent extensor tendons there may not be independent movement of all fingers; extensor indicis also extends the index finger (independently) and extensor digiti minimi extends the little finger (independently) Copyright© 2002 The University of Michigan. Unauthorized use prohibited. Learning Modules - Medical Gross Anatomy Movements of the Upper Limb - Page 18 of 18 Thumb flexion and extension In contrast to the fingers, the thumb can flex at only two joints - the metacarpophalangeal joint and an interphalangeal (IP) joint, since it has only two phalanges. Flexion of the thumb takes place in a plane at an angle to the other digits. When flexed, the thumb points generally toward the 5th MP joint. Muscles: flexor pollicis brevis flexes the MP joint only, while flexor pollicis longus flexes both the MP and IP joints, and is the only muscle to flex the IP joint. Extension of the thumb also occurs in a plane offset from that of the fingers, but the motion has the same effect of taking the thumb posteriorly in the anatomical position. Muscles: extensor pollicis brevis extends the MP joint only, while extensor pollicis longus extends the MP and IP joints, and is the only muscle to extend the IP joint. Copyright© 2002 The University of Michigan. Unauthorized use prohibited.