Hand

The Ultimate Rotator Cuff Training Guide

Rotator Cuff Holistic Treatment

Get Instant Access

Palmar arches.

SHOULDER

The shoulder girdle (pectoral girdle) is composed of the clavicle and scapula. The scapula articulates with the humerus at the glenohumeral joint.

The sternoclavicular joint is the only bony connection between the upper limb and the axial skeleton.

The humeral head is stabilized in the glenoid fossa by the rotator cuff muscles (musculotendinous cuff) composed of the sup rasp inatus, infraspinatus, teres minor, and subscapularis muscles (SITS muscles).

ELBOW

The elbow is a compound joint composed of the humeroradial joint, humeroulnar joint, and proximal radioulnar joint.

The humeroradial and humeroulnar joints permit flexion and extension. The radioulnar joint permits supination and pronation.

WRIST AND HAND

The wrist joints are composed of the radiocarpal joint between the radius and the proximal row of carpal bones (primarily the scaphoid and lunate), the ulnocarpal joint (there is a small fibrous disk between the ulna and the triquetrum), the midcarpal joint between the proximal and distal rows of carpal bones, and the carpometacarpal joints between the distal row of carpal bones and the metacarpal bones.

The carpal tunnel is the space bounded by the flexor retinaculum anteriorly and the carpal bones posteriorly. Passing through the carpal tunnel are nine tendons (four tendons of the flexor digitorum superficialis, four tendons of the flexor digitorum profundus, and the tendon of the flexor pollicis longus) and the median nerve.

Clinical Correlate

Humeral Neck Fracture

The axillary nerve accompanies the posterior humeral circumflex artery as it passes around the surgical neck of the humerus.

A fracture in this area could lacerate both the artery and nerve.

Mid-Shaft Humeral Fracture

The radial nerve accompanies the profunda brachii artery.

Both could be damaged as a result of a mid-shaft humeral fracture.

What deficits would result from laceration of the radial nerve?

Clinical Correlate

Humeral Head Dislocation

Dislocation of the humeral head from the glenohumeral joint typically occurs through the inferior portion of the joint capsule where the capsule is the slackest and is not reinforced by a rotator cuff tendon. After dislocation, the humeral head is pulled superiorly and comes to lie anterior to the glenohumeral joint.

Dislocation may injure the axillary or radial nerve.

Figure 111-4-4.

Clavicle (cut)

Acromion (cut)

Acromion

Deltoid muscle

Capsular ligament Synovial membrane Glenoid labrum Glenoid cavity

Clavicle

Superior glenohumoral ligament

Figure 111-4-4.

process

Inferior glenohumoral ligament

Biceps brach ii S tendon (cut)

Acromion

Capsular ligament Synovial membrane Glenoid labrum Glenoid cavity

Deltoid muscle

Clavicle process

Inferior glenohumoral ligament

Clavicle (cut)

Acromion (cut)

Supraspinatus tendon

Superior glenohumoral ligament

Biceps brach ii S tendon (cut)

Figure 111-4-8. Upper Extremities: PosteroanteriorVlew of Wrist and Hand

Chapter Summary

The motor and sensory supply of the upper limb is provided by the brachial plexus. The plexus is formed by the ventral rami of spinal nerves C5-TI. These rami form superior, middle, and inferior trunks in the posterior triangle of the neck. Anterior and posterior division fibers from each of the three trunks enter the axilla and establish the innervation erf the muscles in the anterior and posterior compartment of the limb. The compartments of the limb and their innervations are given in Table IIU-l. In the axilla, cords of the brachial plexus are formed and give rise to many of the named branches of the brachial plexus induding the five terminal branches: musculocutaneous, median, ulnar, radial, and axillary nerves. Damage to the upper trunk (C5 and C6) of the brachial plexus (Erb paralysis) results in the arm being medially rotated and adducted with the forearm extended and pronated due to loss of the axillary, suprascapular, and musculocutaneous nerves. A lower trunk (C8 and Tl) lesion causes a combined claw and ape hand. Other major lesions of branches of the brachial plexus include wrist drop (radial nerve), ape hand (median nerve), daw hand (ulnar nerve), loss of elbow flexion (musculocutaneous nerve), and loss of shoulder abduction (suprascapular and axillary nerves). Sensory supply from the palmar surface of the hand is supplied by the median nerve (laterally) and the ulnar nerve (medially) and on the dorsal surface of the hand by the radial nerve (laterally) and the ulnar nerve (medially).

The shoulder joint is supported by the rotator cuff muscles: supraspinal, infraspinatus, teres minor, and subscapularis muscles. These muscles hold the head of the humerus in the glenoid fossa.

At the wrist the carpal tunnel is the space deep to the flexor retinaculum and ventral to the carpal bones. The median nerve passes through the canal with the tendons of the flexor digitorum superficial^ and flexor digitorum profundus and the tendon of the flexor pollicis longus musde. There are no vessels in the carpal tunnel.

The arteries that supply blood to the upper limb are a continuation of the subclavian artery. The axillary, brachial, radial, ulnar, and the superficial and deep palmar arch arteries give rise to a number of branches to the limb (Figure 111-4-3).

Was this article helpful?

0 0
31 Days To Bigger Arms

31 Days To Bigger Arms

You can have significantly bigger arms in only 31 days. How much bigger? That depends on a lot of factors. You werent able to select your parents so youre stuck with your genetic potential to build muscles. You may have a good potential or you may be like may of the rest of us who have averages Potential. Download this great free ebook and start learns how to build your muscles up.

Get My Free Ebook


Post a comment