Copyright © 2010 Pearson Education, Inc. Muscles Crossing the Shoulder Joint Nine muscles cross the shoulder joint to insert on and move the humerus
Copyright © 2010 Pearson Education, Inc. Muscles Crossing the Shoulder Joint Some originate off the scapula; others originate off the axial skeleton Three are prime movers of the arm Pectoralis major Latissimus dorsi Deltoid Actions include flexion, extension, adduction, abduction, and rotation of humerus
Copyright © 2010 Pearson Education, Inc. Muscles Crossing the Shoulder Joint Four muscles are rotator cuff muscles Supraspinatus Infraspinatus Teres minor Subscapularis Reinforce the capsule of the shoulder Act as synergists and fixators Two additional muscles are synergists: coracobrachialis and teres major
Copyright © 2010 Pearson Education, Inc. Figure 10.14a Clavicle Deltoid Sternum Pectoralis major Lateral head Long head Medial head Coracobrachialis Triceps brachii: Biceps brachii Brachialis Brachioradialis (a) Anterior view
Copyright © 2010 Pearson Education, Inc. Figure 10.14b Supraspinatus* Spine of scapula (b) Posterior view Deltoid (cut) Greater tubercle of humerus Infraspinatus* Teres minor* Teres major Triceps brachii: Latissimus dorsi Humerus Olecranon process of ulna Lateral head Long head Anconeus * Rotator cuff muscles
Copyright © 2010 Pearson Education, Inc. Table Part 1
Copyright © 2010 Pearson Education, Inc. Muscles Crossing the Elbow Joint Anterior flexor muscles Brachialis and biceps brachii—chief forearm flexors Brachioradialis—synergist and stabilizer
Copyright © 2010 Pearson Education, Inc. Figure 10.14a Clavicle Deltoid Sternum Pectoralis major Lateral head Long head Medial head Coracobrachialis Triceps brachii: Biceps brachii Brachialis Brachioradialis (a) Anterior view
Copyright © 2010 Pearson Education, Inc. Muscles Crossing the Elbow Joint Posterior extensor muscles Triceps brachii—prime mover of forearm extension Anconeus—weak synergist
Copyright © 2010 Pearson Education, Inc. Figure 10.14b Supraspinatus* Spine of scapula (b) Posterior view Deltoid (cut) Greater tubercle of humerus Infraspinatus* Teres minor* Teres major Triceps brachii: Latissimus dorsi Humerus Olecranon process of ulna Lateral head Long head Anconeus * Rotator cuff muscles
Copyright © 2010 Pearson Education, Inc. Table Part 2
Copyright © 2010 Pearson Education, Inc. Muscles of the Forearm Actions: movements of the wrist, hand, and fingers Most anterior muscles are flexors and insert via the flexor retinaculum Most posterior muscles are extensors and insert via the extensor retinaculum
Copyright © 2010 Pearson Education, Inc. Muscles of the Forearm Some forearm muscles act to produce pronation and supination of the forearm
Copyright © 2010 Pearson Education, Inc. Muscles of the Forearm Pronators: pronator teres and pronator quadratus Supinator: a synergist with the biceps brachii
Copyright © 2010 Pearson Education, Inc. Muscles of the Forearm: Anterior Compartment Flexors Flexor carpi radialis Palmaris longus Flexor carpi ulnaris Flexor digitorum muscles (superficialis and profundus) Flexor pollicis longus
Copyright © 2010 Pearson Education, Inc. Figure 10.15a Biceps brachii Tendon of biceps brachii Pronator teres Brachioradialis Extensor carpi radialis longus Flexor pollicis longus Pronator quadratus Flexor retinaculum Medial head of triceps brachii Medial epicondyle of humerus Flexor carpi radialis Palmar aponeurosis Superficial transverse ligament of palm Palmaris longus Flexor carpi ulnaris Flexor digitorum superficialis (a)
Copyright © 2010 Pearson Education, Inc. Figure 10.15c Supinator Tendon of flexor carpi ulnaris (cut) Tendon of flexor digitorum profundus Flexor pollicis longus Thenar muscles of thumb Tendon of flexor pollicis longus Lumbricals Tendon of flexor digitorum superficialis (cut) Pronator quadratus Flexor digitorum profundus (c)
Copyright © 2010 Pearson Education, Inc. Muscles of the Forearm: Posterior Compartment Extensors Extensor carpi radialis longus and brevis Extensor digitorum Extensor carpi ulnaris Extensor pollicis brevis and longus Extensor indicis Abductor pollicis longus
Copyright © 2010 Pearson Education, Inc. Figure 10.16a Insertion of triceps brachii Anconeus Flexor carpi ulnaris Extensor carpi ulnaris Extensor digiti minimi Extensor indicis Tendons of extensor carpi radialis brevis and longus Extensor expansion (a) Extensor pollicis longus Extensor pollicis brevis Abductor pollicis longus Extensor digitorum Extensor carpi radialis brevis Extensor carpi radialis longus Brachioradialis Tendons of extensor digitorum
Copyright © 2010 Pearson Education, Inc. Figure 10.16b Olecranon process of ulna Interossei Anconeus Supinator Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis Extensor indicis (b)
Copyright © 2010 Pearson Education, Inc. Movements of the Wrist and Fingers Flexion and extension Abduction and adduction
Copyright © 2010 Pearson Education, Inc. Figure Part 3