They include the subscapularis supraspinatus infraspinatus and teres minor The

They include the subscapularis supraspinatus

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They include the subscapularis, supraspinatus, infraspinatus, and teres minor. The tendons of these muscles form a cap, or a cuff, over the proximal humerus, thus stabilizing the joint capsule. The muscles help rotate the arm at the shoulder joint. Muscle that move the Forearm Most of the muscles that move the forearm (ulna and radius) are located along the humerus and are classified as flexors, extensors, supinators, or pronators. The flexors, those that cause flexion at the elbow joint, include the biceps brachii, brachialis, and brachioradialis. Extension is due to contraction of the triceps brachii. The triceps brachii lies along the posterior surface of the humerus; it has its origins on the scapula and humerus and its insertion on the ulna. Contraction causes extension of the forearm at the elbow joint; it also extends the arm at the shoulder joint. The biceps brachii is located along the anterior surface of the humerus; its two heads attach to the scapula (origin), and the distal end inserts on the radius of the forearm. The biceps brachii acts synergistically with the brachialis and brachioradialis to flex the forearm. Pronation (palm down) is achieved by two pronator muscles located along the anterior forearm (origin on the humerus and ulna, insertion on the radius). The actions of the biceps brachii and a supinator muscle (origin on the humerus and ulna, insertion on the radius) located along the posterior forearm cause supination (palm up). Muscles That Move the Wrist, Hand, and Fingers The flexors are located on the anterior surface of the forearm, and the extensors are located on the posterior surface. The tendons of these muscles pass through the wrist into the hand and fingers. The flexor carpi radialis and the flexor carpi ulnaris flex the hand at the wrist joint; they also adduct and abduct the hand at the wrist. Contraction of the flexor digitorum muscle (in the forearm) pulls on the tendons of the phalanges, thereby moving the fingers (like puppet strings). The extensors of the wrist, hand, and fingers lie along the posterior forearm. The extensor carpi radialis longus extends and abducts the hand at the wrist. The extensor carpi ulnaris extends and adducts the hand at the wrist. The extensor digitorum extends the hand at the wrist and extends the fingers. The flexors of the fingers are stronger than the extensors so that in a relaxed hand, the fingers are slightly flexed. Carpel Tunnel
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The flexor tendons in the carpal tunnel are encased in tendon sheaths and normally slide back and forth very easily. However, repetitive motion of the hand and fingers can cause the tissues within the carpal tunnel to become inflamed and swollen. The swelling puts pressure on the median nerve, which is also located in the carpal tunnel. Muscles That Move the Thigh, Leg, and Foot The muscles that move the thigh at the hip all attach to some part of the pelvic girdle (coxal bones) and the femur (thigh bone). These include the gluteal muscles, the iliopsoas, the tensor fascia latae, and a group of adductor muscles. Contraction of these muscles causes movement at the hip joint.
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  • Fall '19
  • muscle weakness, muscle atrophy, functions of muscles

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