The Bones of the Upper Limb

The bones comprising the upper limb include the clavicle (collar bone) and scapula (shoulder blade) in the pectoral girdle; the humerus in the arm; the radius and ulna in the forearm; the eight carpal bones in the wrist; the five metacarpal bones in the hand; and the 14 phalanges in the fingers (digits) (Figure 10-1).

Figure 10-1 The bones of the right upper limb.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 65.)

The Brachial Plexus

The brachial plexus is a complex of nerves serving the upper limb, which provides the following physiologic functions:

At the root of the neck, the five anterior rami of the spinal nerves from C5 to C8 and T1 unite to form the brachial plexus in the posterior triangle of the neck. (Remember there are seven cervical spinal vertebrae and eight cervical spinal nerves because spinal nerves C1 and C2 originate from the superior and inferior sides of C1, respectively.) The union of the five anterior rami and the rearrangement of the five cervical spinal nerves allow the nerve fibers derived from different segments of the spinal cord to be arranged and distributed efficiently in different nerve trunks to the various parts of the upper limb. The plexus can be divided into roots, trunks, divisions, and cords (Figure 10-2).

Figure 10-2 Diagram of the brachial plexus.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 80.)

The brachial plexus divides its nerves into supraclavicular branches and infraclavicular branches. Supraclavicular branches arise from the rami and trunks of the brachial plexus and are distributed in the posterior triangle of the neck and above the level of the clavicle. Infraclavicular branches arise from the cords of the brachial plexus and are distributed through the axilla (armpit) from where they are distributed to the arm.

Supraclavicular Branches of the Brachial Plexus

Supraclavicular branches include the following nerves and the following major muscles and joints that they innervate:

• Dorsal scapular nerve (C5): scalenus medius, levator scapulae, and rhomboids Acupoint H13 is formed on the levator scapulae muscle

• Long thoracic nerve (C5 to C7): scalenus medius, serratus anterior

• Nerve to the subclavius (C5)

• Suprascapular nerve (C5 and C6): supraspinatus, infraspinatus, and the shoulder joint. Acupoint H8 is formed on the infraspinatus muscle.

Infraclavicular Branches of the Brachial Plexus

The lateral cord of the brachial plexus includes three branches:

• Lateral pectoral nerve (C5 to C7): pectoralis major. Acupoint H17 lateral pectoral is formed where the nerve enters the muscle

• Musculocutaneous nerve (C5 to C7): The muscles of the anterior aspects of the arm. This nerve continues in the arm to supply the biceps brachii and the brachialis muscles (Figure 10-3). Just proximal to the elbow joint, this nerve penetrates the deep fascia and becomes a superficial nerve named the lateral antebrachial cutaneous nerve; at this point acupoint H9 lateral antebrachial cutaneous is formed

• Lateral root of the median nerve: This nerve is the continuation of the lateral cord of the brachial plexus. It is joined by the medial root of the median nerve to form the median nerve

Figure 10-3 Nerves and vessels of the arm. Pay attention to the musculocutaneous nerve.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 125.)

The medial cord of the brachial plexus includes five branches:

• Medial pectoral nerve (C8 and T1): pectoralis minor and part of pectoralis major

• Medial brachial cutaneous nerve (C8 and T1): the skin over the medial surface of the arm and the proximal part of the forearm

• Medial antebrachial cutaneous nerve (C8 and T1): the skin over the medial surface of the forearm

• Ulnar nerve (C8 and T1): this nerve does not give branches in the axilla and passes through the arm into the forearm and hand. As it enters the forearm from behind the medial epicondyle, it supplies the flexor carpi ulnaris; the medial half of the smallest muscles of the flexor digitorum profundus; and the skin on the ulnar side of the hand. The muscular and cutaneous supply of the ulnar nerve is summarized in Table 10-1

• Medial root of the median nerve: the medial root joins with the lateral root to form the median nerve (Table 10-2), which supplies all the flexor muscles in the forearm (except the flexor carpi ulnaris) and the skin on the lateral half of the palm. In the palm, the median nerve supplies the muscles of the thenar eminence and the first two lumbricals. The cutaneous branches of the median nerve provide sensory information from the skin on the palmar aspect of the lateral (radial) three fingers and radial half of the ring fingers

Table 10-1 A Summary of Main Innervation of the Ulnar Nerve (C8 and T1)

Upper Arm	Forearm	Hand
Elbow joint	Flexor carpi ulnaris Flexor digitorum profundus (median half) Ulnar artery Palmar cutaneous branch Posterior cutaneous branch Wrist joint

Muscles of hypothenar eminence

Adductor pollicis 3rd and 4th lumbricals

Interossei joints of hand

Palmaris brevis

Palmar digital branches to medial 1½ fingers

Skin of medial side of dorsum of hand and medial 1½ fingers

Table 10-2 A Summary of the Main Innervation of the Median Nerves (C5, C6, C7, C8, T1)

Upper Arm	Forearm	Hand
Brachial artery Elbow joint

Glenohumeral Joint

Motion of the arm requires action at all joints of the shoulder complex. The glenohumeral joint has more freedom of motion than any other joint in the body. Therefore this joint is the most important member of the shoulder complex, as well as the most frequent site of pain and impairment. This synovial joint has an incongruous ball-and-socket articulation. The articulation is made up of the large head of the humerus and the small and shallow glenoid fossa. Rather than merely rotating about a fixed axis, the head of the humerus also slides against the glenoid articulation surface (Figure 10-4). This intrinsic weakness of the joint makes it susceptible to degenerative changes and derangement and also renders the stability of the joint dependent on the supporting soft tissues.

Figure 10-4 The bones of the shoulder joint. Anterior (A and C) and posterior (B and D) views of the scapula. Origins of the muscle are gray and insertions are dark.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 73.)

The concave pear-shaped glenoid fossa is located at the lateral tip of the scapula (see Figure 10-4), which allows little close contact of the two articular surfaces. The shallow glenoid fossa is deepened by a lip, the glenoid labrum, surrounding the fossa. The glenohumeral capsule is attached to the lip. The glenohumeral articulation is a multiaxial ball-and-socket joint that allows movement in three axes.

The head of the humerus is larger than the socket of the scapula by approximately a factor of four. When the arm hangs down naturally at the side, the head of the humerus is held in the glenoid fossa against the force of gravity predominantly by the supraspinatus muscle and by the superior aspect of the capsule. The supraspinatus muscle originating within the supraspinatus fossa of the scapula attaches to the greater tuberosity of the humerus. Thus, it is always necessary to manually palpate the supraspinatus muscle and its attachment on the tuberosity of the humerus when treating shoulder pain.

Four scapular muscles—supraspinatus, infraspinatus, teres minor, and subscapularis—form a musculotendinous rotator cuff to protect the glenohumeral joint and provide for its stability (Tables 10-5 and 10-6). All these rotator cuff muscles, except the supraspinatus, rotate the head of the humerus within the glenoid fossa. The tendons of these four muscles join the articular capsule of the glenohumeral joint and form a mass of tendons fused with the lateral part of the capsule. All the rotator cuff and deltoid muscles and their attachments to the head of the humerus should be carefully palpated and needled for any kind of shoulder disorder.

Table 10-6 Prime Movers of the Glenohumeral Joint

The capsule of the joint is thick and strong but lax, especially inferiorly, so as to allow a greater range of motion. Glenohumeral motion will be restricted if pathologic conditions such as inflammation, contracture, or fibrosis occur in the capsule. Acupuncture needling reduces inflammation and relaxes the contracture of the capsule, but is not helpful in cases of fibrosis.

A bursa is a flattened sac filled with a lubricant called synovial fluid that enables the two flattened walls of the sac to slide freely over each other. The bursa eliminates the friction that would arise wherever a muscle or tendon could rub against another muscle, tendon, or bone. There are several bursae specifically associated with the glenohumeral joint (Figure 10-5). The important ones are the subacromial and subdeltoid bursae. These bursae separate the supraspinatus tendon and the head of the humerus from the acromion and the deltoid muscle. Frequently bursitis, the inflammation of the bursae, may occur with shoulder pain. Acupuncture needling is very effective in reducing bursitis. However, needling efficacy is slower if the walls of the bursa adhere to each other (adhesive bursitis). If a patient is diagnosed with adhesive bursitis, acupuncture needling is still recommended as a noninvasive therapy while the patient is seeking other medical modalities to alleviate the condition.

Figure 10-5 Subacromial bursa of the shoulder joint.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 96.)

Acromioclavicular Joint

The acromioclavicular (AC) joint is a plane (flat) synarthrodial joint. It consists of the small convex facet on the lateral end of the clavicle and a small concave facet on the acromion of the scapula. This configuration allows rotation. The two bones are joined by fibrous tissue that gradually degenerates and forms a meniscus between them. The AC joint itself is not strong enough to hold the two bones together and is reinforced by the coracoclavicular ligament. This ligament consists of two smaller ligaments: the quadrangular trapezoid ligament and the cone-shaped conoid ligament. These two ligaments prevent separation of the clavicle and scapula. The primary function of the AC joint is to maintain coordination between the clavicle and the scapula during movements of the shoulder (Figure 10-6).

Figure 10-6 The acromioclavicular joint. The joint is covered by the acromioclavicular ligament.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 75.)

Trauma may tear the fibers of the AC joint, resulting in instability of the joint during shoulder movement. When examining patients with shoulder pain, it is necessary to palpate the area of the AC joint to find local pain or tenderness. Acupuncture needling reduces pain and inflammation, but if dislocation or subluxation is suspected, patients should be referred for further medical evaluation and treatment.

Sternoclavicular Joint

This joint is the only bony articulation between the upper limb and the axial skeleton. The sternoclavicular (SC) joint is formed by the articulation of the sternal end of the clavicle with the flat fossa of the clavicular notch on the superior lateral margin of the sternum and the cartilage of the first rib. A small articular disk is present between these bones with strong ligamentous support (Figure 10-7). The comparatively large sternal end of the clavicle rotates and forms the lateral boundary of the jugular notch. The SC joint allows the clavicle and shoulder to move up and down, forward and backward, or any combination of these movements.

Figure 10-7 The sternoclavicular joint and associated ligaments. The left joint has been sectioned to expose the articular disk.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 74.)

The fibrous capsule of the SC joint is a key structure in supporting the weight of the entire upper limb. The SC joint is well supported and protected by anterior and posterior SC ligaments. The two clavicles are also joined to each other by an interclavicular ligament. Together these ligaments prevent the lateral and upward dislocation of the clavicle. The joint is further strengthened by the costoclavicular ligament that connects the first rib and the inferior surface of the clavicle.

When treating shoulder pain, it is necessary to carefully palpate the SC joint area to find localized pain and tenderness. This area is very close to the lung so practitioners should pay special attention to the direction and depth of needling. It is advisable to use only 1.5 cm needles in this region and to insert needles into the fibrous tissue to reduce pain and inflammation.

Scapulothoracic Joint

The scapulothoracic (ST) joint is not a true anatomic joint but a functional “joint” that maintains a direct relationship between the scapula and the thorax as the scapula slides over the ribs. The movement of the scapula is coordinated with the AC and SC joints.

In a neutral position, the scapula rests on the posterior thorax approximately 5 cm from the midline, between the 2nd through the 7th ribs. From this reference position, the scapula can have movements of elevation-depression (raising or depressing the shoulder), abduction-adduction (away from or toward the midline), and upward-downward rotation (raising the arm over the head or using the hand to touch the lower back). This ST joint is stabilized by the adjacent AC and SC joints and muscles that attach to both the thorax and scapula. Muscle pain associated with scapular movement is a common symptom encountered in most patients.

Acupuncture practitioners should understand the position of the scapula during its movement for three reasons: (1) to identify the painful muscles associated with the scapula, (2) to palpate the acupoint H8 infrascapularis, which is located at the center of the infrascapular fossa of the scapula, and (3) to ensure safe needling on the thorax when the scapula changes its position.

Many patients complain of pain in the area between the upper spine and the medial border of the scapula. Our clinical experience indicates that about 70% of the patients have pain or tenderness in the levator scapulae, rhomboideus minor and major muscles, especially the parts of these muscles that are close to the medial border of the scapula. When administering acupuncture treatment, we use the following methods to avoid puncturing the lung: (1) use 1.5 cm long needles, (2) grasp and lift up the muscle for deeper needling, or (3) put the patient’s forearm on the back to raise the medial border of the scapula and then tilt and insert 4 cm needles to the attachment area of these muscles (see Figure 10-30).

Figure 10-30 Prone position. Left upper limb in cross-back adduction position for shoulder pain.

Bicipital-humeral Joint

The bicipital-humeral “joint,” like the scapulothoracic joint mentioned above, is also a nonanatomic but functional joint. It is an important area in the treatment of shoulder pain.

The biceps brachii muscle, as its name implies, has two heads, the long and the short (Figure 10-8). Here we focus on the tendon of the long head because it is frequently a source of shoulder pain. The long head has a long tendon that traverses the intertubercular groove on the humerus bone, passes through the glenohumeral jont, and finally attaches to the top of the glenohumeral joint (the supraglenoid tubercle).

Figure 10-8 The biceps brachii muscle.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 121.)

Patients with shoulder pain always complain of tenderness or pain at this bicipital-humeral “joint” upon palpation. Thus, this area contains symptomatic acupoints for treating shoulder pain by acupuncture needling.

Scapular Movements

Elevation of the scapula is produced by four muscles (Figure 10-9). The medial border of the scapula is elevated by three muscles, the levator scapulae and the rhomboideus minor and major. The lateral angle of the scapula is changed by the upper fibers of the trapezius connected to the clavicle, acromion, and spine of the scapula. Often we examine patients with one shoulder higher than the other because of the tightness of these four muscles. The shoulder level returns to normal after proper needling of these muscles.

Figure 10-9 Elevators of the scapula.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 98.)

Muscles involved in depression of the scapula include the pectoralis minor and major, subclavius, latissimus dorsi, lower fibers of the trapezius, and serratus anterior (Figure 10-10). In some patients with upper or lower back pain, one shoulder is lower than the other and needling both the lower back muscles and the depressor muscles returns the shoulder to normal level.

Figure 10-10 Depressors of the scapula. A, Anterior view. B, Posterior view.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 99.)

When abduction occurs, such as when raising an arm, the scapula rotates upward. Upward rotation is brought about by the combined action of the trapezius and the serratus anterior (Figure 10-11). When reaching down to pick up something from the floor, the scapula rotates downward. Downward rotation is carried out by the combined action of raising the medial border and lowering the lateral angle of the scapula. The levator scapulae and both rhomboids are responsible for raising the medial border, while the pectoralis major and minor and latissimus dorsi, aided by gravity on the free limb, are responsible for lowering the lateral angle of the scapula (Figure 10-12).

Figure 10-11 Upward rotators of the scapula.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 99.)

Figure 10-12 Downward rotation of the scapula. A, Anterior view. B, Posterior view.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 100.)

The pectoralis major, minor, and serratus anterior bring about protraction (Figure 10-13), while the middle fibers of the trapezius carry out retraction (Figure 10-14).

Figure 10-13 Protractors of the scapula.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 100.)

Figure 10-14 Retractors of the scapula.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 101.)

Humeral Movements

Coordinated action of the anterior portion of the deltoid, the clavicular portion of the pectoralis major, the coracobrachialis, and the biceps brachii brings about the flexion of the arm at the shoulder joint. The posterior fibers of the deltoid, the latissimus dorsi, the sternocostal fibers of the pectoralis major, the teres major, and the long head of the biceps brachii are responsible for extension of the arm.

Abduction of the arm is carried out by the deltoid, especially its lateral part and the supraspinatus, while adduction of the arm is carried out by the pectoralis major, teres major, and latissimus dorsi, which are to a small extent assisted by the coracobrachialis and the long head of the triceps brachii.

Internal (medial) rotation is brought about primarily by subscapularis. Other internal rotators include pectoralis major, latissimus dorsi, teres major, and clavicular fibers of the deltoid. External (lateral) rotation is performed by infraspinatus and teres minor, and also by the posterior fibers of the deltoid if extension and lateral rotation are combined. Figure 10-15 explains the topographic relationship between the internal and external rotators of the humerus.

Figure 10-15 Medial rotators and lateral rotators of the humerus. Superior view of the right arm.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 105.)

Subacromial Space

The subacromial space can be affected with rotator cuff tendinitis, calcific tendinitis, impingement syndrome, and rotator cuff tear.

Bicipital Groove

The bicipital groove can be involved in bicipital tendinitis and biceps tendon subluxation and tear.

Acromioclavicular Joint

Pain in this joint may be caused by degenerative and infectious conditions.

Anterior Glenohumeral Joint

Pain in the anterior glenohumeral join can be caused by glenohumeral arthritis, osteonecrosis, glenoid labial tear, and adhesive capsulitis.

Sternoclavicular Joint

Pain in this joint can be caused by trauma, infection, or degenerative changes.

Posterior Edge of Acromion

Pain found in this region is related to rotator cuff tendinitis, calcific tendinitis, and rotator cuff tear.

Suprascapular Notch

Nerve entrapment may happen at this region, which causes pain.

Quadrilateral Space

Tenderness and pain, which may be caused by axillary nerve entrapment or inflammation, are palpable in most patients with shoulder pain.

Muscle Pain

All of the pain that occurs in any of the above-mentioned locations can cause or refer muscle pain. Carefully palpate this area to examine muscles on the scapula (both infraspinous and supraspinous fossae).

Muscles

The arm muscles consist of two groups: flexor and extensor (Table 10-9). The flexor muscles are coracobrachialis, biceps brachii, and brachialis. As discussed above, the biceps brachii has two heads, the long head being a common source of pain because of its long tendon, which spans the glenohumeral joint and is attached to the supraglenoid tubercle. Pain from the long head of the biceps brachii is palpable right on the region of the intertubercular groove on the head of the humerus.

The biceps brachii and brachialis muscles are powerful flexors of the elbow. The former also serves as the major supinator of the forearm (for example, allowing us to turn our palms up). The flexor muscles are innervated by the musculocutaneous nerve.

The triceps muscle serves as the prime extensor of the arm. This muscle is a strong extensor of the elbow and a weak extensor of the shoulder. This muscle is innervated by the radial nerve.

Nerves

Four main nerves traverse the arm: median, ulnar, musculocutaneous, and radial. The median and ulnar nerves do not give off branches to the muscles of the arm (Table 10-10).

The musculocutaneous nerve arises from the lateral cord of the brachial plexus (C5 to C7), passes through the coracobrachialis muscle, and runs between the biceps brachii and brachialis. After sending branches to innervate these three muscles, the musculocutaneous nerve continues as the lateral antebrachial cutaneous nerve, which reaches laterally to the biceps tendon at the cubital fossa. At this location the nerve penetrates the brachial fascia to innervate the skin of the forearm and an acupoint is formed: H9 lateral antebrachial cutaneous.

The radial nerve leaves the axilla and runs posteriorly between the long head of the triceps and the humerus. As it runs deep to the triceps, the radial nerve gives branches to all three heads of this muscle with fibers from C6 to C8.

Flexors and their Innervation

The eight flexor muscles are arranged into three layers (Figures 10-18 through 10-20). These muscles (Table 10-12) perform the following functions:

Figure 10-18 The superficial flexor muscles of the right forearm. The starred muscles are extensors.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 144.)

Figure 10-19 The intermediate muscle layer of the right forearm. Supinator is an extensor muscle.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 145.)

Figure 10-20 The deepest flexor muscles of the right forearm. The supinator (starred) is an extensor muscle of the forearm.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 145.)

The superficial layer includes pronator teres, flexor carpi radialis, palmaris longus, and flexor carpi ulnaris. All four muscles form a common tendon that attaches to the medial epicondyle of the humerus. Repetitive wrist flexion or pronation movements occurring in sports (e.g., golf) or other occupations such as the performance of music (e.g., piano, mandolin) may injure these muscles and their common tendon and cause medial epicondylitis.

The flexor digitorum superficialis forms the intermediate layer. It originates from the proximal ulna and the proximal radius. The median nerve passes behind this attachment and may be entrapped. In the distal third of the forearm, the flexor digitorum superficialis muscle gives rise to four tendons: the two superficial tendons go to the middle and ring fingers and the two deep tendons go to the index and little fingers.

The deep layer contains three muscles: flexor digitorum profundus, flexor pollicis longus, and pronator quadratus. The flexor digitorum profundus has an extensive origin from the proximal ulna and the membrane between the ulna and the radius (interosseous membrane). This muscle ends in four tendons that pass the flexor retinaculum and is inserted on the base of the distal phalanges of each of the four fingers.

The flexor pollicis longus arises from about the middle half of the radius. This muscle forms a tendon that passes through the carpal tunnel and is inserted on the base of the distal phalanx of the thumb.

The pronator quadratus is a flat quadrangular muscle that arises from the distal fourth of the ulna and is inserted on the distal part of the radius. Its action is to pronate the forearm and hand. Therefore this muscle is often subject to repetitive injury. Tenderness can be palpable in this area.

The ulnar nerve runs posterior to the medial epicondyle and enters the forearm (Figure 10-21). In the forearm, it runs along the bone of the ulna, emerges from the lateral side of flexor carpi ulnaris, and continues to the hand. The median nerve runs practically straight down the middle of the forearm (Figure 10-22).

Figure 10-21 The muscles innervated by the ulnar nerve.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 154.)

Figure 10-22 The muscles innervated by the median nerve.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 152.)

Extensors and their Innervation

The 11 extensor muscles of the forearm (Table 10-13) are arranged into superficial (Figure 10-23) and deep layers (Figure 10-24). The radial nerve innervates all 11 extensor muscles (Figure 10-25) and they perform the following functions:

Figure 10-23 The superficial extensor muscles of the right forearm.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 161.)

Figure 10-24 The deeper extensor muscles of the right forearm.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 161.)

Figure 10-25 The innervation of the radial nerve.

(From Jenkins D: Hollinshead’s functional anatomy of the limbs and back, ed 8, Philadelphia, 2002, WB Saunders, p 168.)

The superficial muscle group arises from the supracondylar ridge and the lateral epicondyle (common extensor tendon) of the humerus. Four muscles attach to this common extensor tendon: extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris. Repetitive wrist and finger extension such as in some sports and occupations may injure these muscles and cause inflammation of the common extensor tendon (e.g., lateral epicondylitis or tennis elbow).

Tendons crossing the dorsal wrist will be discussed next.

Soft Tissue Pain and Injuries due to Overuse (Repetitive Motion Disorders)

Repetitive motion disorders (RMDs)—also referred to as overuse injuries, repetitive stress syndromes, and activity-related musculoskeletal disorders—are often caused by occupations requiring computer use or by sports activities. Many sports participants develop overuse injuries.

The physical processes that cause RMDs can be repetition, sustained loading, and cumulative trauma. RMDs can involve different soft tissues such as muscles, nerves, ligaments, and tendons. Injuries to these tissues show that the accumulated biomechanical stress that has been applied to them is beyond their tolerance. The biomechanical stress is most likely to cause injury at those anatomic locations where tendons change directions, traverse narrow tunnels, pass through a pulley, or are impinged upon by surrounding structures. If the injury is not properly treated, the anatomy and composition of the tendon may change from that of a regularly arranged dense connective tissue to that of fibrocartilage.

The pathological conditions of irritated tendons may be different. The underlying pathologic entities can be tendinitis (inflammation of the tendon), peritendinitis (inflammation of the tendon and its sheath), or tendinosis (degeneration of the tendon). Our clinical experience shows that most of these tendon problems respond well to acupuncture needling if treated together with their corresponding muscles. Tight muscles always transfer the pulling force to the tendons and cause inflammation of the tendons. The stress on the tendons can only be relieved if the muscles are relaxed and flexible.

Sometimes it is difficult to distinguish a particular pathologic condition because many soft tissues may be involved and different disorders may coexist. For example, shoulder pain in a patient may represent one or all of these disorders: rotator cuff tendinopathy, subacromial bursitis, acromioclavicular arthritis, or bicipital tendinitis. Acupuncture can achieve faster and better results when the pathologic conditions are simpler and fewer. Slower and less efficient results can be expected when the pathologic conditions are many and complicated.

Rotator Cuff Tendinopathy

Four scapular muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) fuse their tendons with the fibrous capsule of the glenohumeral joint to form a musculotendinous cuff. The rotator cuff protects and stabilizes the shoulder joint by holding the head of the humerus in the glenoid cavity of the scapula (see the section on the glenohumeral joint). The supraspinatus helps abduct the arm and the other three rotator cuff muscles rotate the humerus.

The rotator cuff may be damaged or torn by injury and trauma as a result of prolonged or repetitive use of the upper extremity, particularly in an abducted position. The supraspinatus tendon is the most commonly torn structure of the rotator cuff. Some sports activities, such as baseball pitching, tennis, and bowling, are particularly liable to cause this damage.

Rotator cuff tears are both age-related and activity-related, and create a condition in which neither abduction nor external rotation are possible. During the initial stage, the tear is a relatively minor injury that might not be noted, but if left untreated, the initial tear can develop into a larger tear. Rotator cuff tears can be either incomplete (partial) or complete (total) tears. Pain is often progressive and may radiate to the base of the neck or down the lateral aspect of the arm. Abduction activities become weak and painful.

Degenerative tendinosis of the musculotendinous rotator cuff is a common disease in senior people. Calcium deposits can be formed in the tendon of the supraspinatus and other rotator cuff muscles.

Acupuncture efficacy varies in treating rotator cuff symptoms, depending on the nature of the tendinopathy. Acupuncture alone can achieve good results in patients with early pathologic conditions of the rotator cuff, including minor calcium deposits. The reason for this is unclear, but we speculate that the muscles are relaxed when they obtain better blood circulation and cleansing, so that the minor calcium deposit does not interfere with their movement; or the improved blood circulation may gradually render the minor calcium deposit dissolvable. Acupuncture efficacy decreases as the pathologic condition is more serious. Acupuncture is not effective in cases of severe rotator cuff damage but can be helpful in recovery of the muscles after surgery.

Frozen Shoulder (Adhesive Capsulitis, Adhesive Bursitis)

A normal glenohumeral capsule has a volume of 30 ml of fluid. If the capsular fluid decreases, some parts of the capsule lining will adhere to each other or to the head of the humerus. This pathologic condition reduces the capsular elasticity, resulting in limitation of glenohumeral action. The pain is felt at the end point of any shoulder joint motion. This condition is seen more frequently in patients over 50 years of age. Acupuncture is able to relax the muscles and promote blood circulation, which helps to cleanse wastes, and the needle-induced lesions will reduce inflammation. These functions may help restore the normal structure and function in some patients suffering from frozen shoulder, but in severe cases acupuncture cannot reverse the pathological condition and other medical modalities will be needed.

Subacromial Bursitis (Calcific Bursitis, Scapulohumeral Bursitis)

A bursa is a small fluid-filled sac or saclike cavity situated where friction would otherwise occur. Subacromial bursae lie between the acromion and supraspinatus tendon and extend between the deltoid and greater tubercle. Inflammation of the subacromial bursa can be the underlying cause of acute or chronic shoulder pain (see Figure 10-5). Patients with subacromial bursitis complain of pain and tenderness in the lateral shoulder, with pain that worsens during movement. In chronic cases, the bursa may become thickened and fibrotic, although this pathologic change may not be radiographically detectable. A calcium deposit can develop in the subdeltoid or subacromial bursa.

Acupuncture treatments are very effective in cases of acute subacromial bursitis and help to reduce pain in mild and moderate cases. Needling the freshly inflamed soft tissues increases blood circulation and reduces the pain, swelling, and inflammation. The tissue reaction to the needling helps to digest the damaged cells and replace them with new cells. However, if the condition becomes chronic, more treatment sessions are needed and the efficacy varies according to the healability of the condition.

Bicipital Tendinitis

The tendon of the long head of the biceps ascends in the intertubercular (bicipital) groove of the humerus and enters the glenohumeral capsule. Within the capsule the tendon crosses the head of the humerus and attaches to the supraglenoid tubercle of the scapula (see Figure 10-8). The long course and angulation of this tendon make it susceptible to tears and degenerative changes. Pain or tenderness is anterior to the shoulder and radiates down the anterior arm.

Acupuncture needling usually helps if only inflammation of the tendon is involved because acupuncture needling induces antiinflammatory reaction and tissue regeneration. The treatment should include needling both the muscles and inflamed tendons. If rupture of the transverse humeral ligament or displacement of the tendon out of the intertubercular groove are suspected, consult an orthopedic surgeon immediately.

Epicondylitis

Medial and lateral epicondylitis is a common cause of pain in the elbow and forearm. The most likely cause of this condition is repetitive overuse or trauma. Age-related degenerative tendinosis may be the underlying cause in some cases. Seemingly the pain is localized over the respective epicondyle with radiation into the forearm. However, tender points can be found by careful palpation of the extensor muscles (lateral epicondylitis) or flexor muscles (medial epicondylitis). These muscle tender points should be needled together with the lateral or medial common tendon.

Epicondylitis, if related to repetitive overuse of the arm, usually results from stressful, tight, or damaged muscles. Needling these muscles is even more important than needling the common tendon. Acupuncture usually provides very good results in most patients with epicondylitis, especially in those with acute onset from sport activities. Self-healable sports injuries such as those caused by repetitive overuse are usually soft tissue injuries with inflammation and swelling. Athletes usually maintain good self-healing potential, so acupuncture needling can achieve satisfactory results. If epicondylitis is caused by age-related necrotic change, less efficacy can be expected and more treatments are needed to reduce the inflammation and pain.

Olecranon Bursitis

Symptoms of olecranon bursitis may include pain, tenderness, swelling, and warmth in the posterior elbow. Olecranon bursitis is usually caused by overuse, recurrent trauma, inflammation, or infection. Patients with rheumatic disease may have acute aseptic inflammatory olecranon bursitis.

Because needling can promote immune reaction to reduce inflammation, acupuncture treatments are usually effective in treating olecranon bursitis. Both the inflamed bursa and the muscles of the arm and forearms should be treated together because the inflamed bursa irritates the muscles and makes them tight, resulting in low blood circulation to the inflamed soft tissues. Needling relaxes the muscles and increases the blood circulation, which reduces the inflammation of the bursa and promotes regeneration of the fresh tissues.

Localized Median Nerve Lesion: Carpal Tunnel Syndrome

In its course from the neck to the hand, the median nerve can be entrapped in several locations: (1) in the cubital fossa, the median nerve is entrapped by the pronator teres muscle or flexor digitorum superficialis from repetitive strain; (2) in the forearm, the median nerve is injured by direct trauma or forearm fracture, which causes weak thumb activity; (3) the most common median nerve neuropathy is the entrapment of the median nerve in the carpal tunnel at the wrist. We have many patients with carpal tunnel syndrome (CTS) whose professions require substantial use of computers.

The carpal tunnel is a narrow fibro-osseous passage through which 10 structures pass: the median nerve, the flexor pollicis longus tendon, four tendons of the flexor digitorum superficialis, and four tendons of the flexor digitorum profundus (Figure 10-29). All eight flexor tendons in the carpal tunnel share the same common synovial sheath (also called the ulnar bursa) formed by the synovial membrane. Sufficient synovial fluid is contained in the bursa to lubricate and hence facilitate the movement of the tendons beneath the retinaculum.

Figure 10-29 Transverse section through the carpal tunnel to show its contents. In cases of carpal tunnel syndrome, directly needling into the tunnel helps reduce swelling and pain and promote healing.

(From Gosling J, Harris P, Whitmore I, Willan P: Human anatomy: color atlas and text, ed 4, Edinburgh, 2002, Mosby, p 119.)

Any pathologic conditions that significantly increase the pressure inside the carpal tunnel or reduce the size of the carpal tunnel (e.g., edema, inflammation of the flexor retinaculum, anterior dislocation of the lunate bone, rheumatoid thickening of the synovial membrane of the tendon sheaths, and tenosynovitis of the tendon sheaths) may cause compression of the median nerve as well as the tendons. Most patients with CTS are between 40 and 60 years of age and the syndrome is more common in women, possibly because women have less physical training than men. Those workers with jobs that require use of repetitive wrist motion (computer programmers and bank tellers) or forced hand movement are more susceptible to CTS.

CTS is characterized by pain on the palmar-radial aspect of the hand, and the pain often becomes worse at night and may be severe enough to wake the patient. When tapped on the palm side of the wrist, patients experience a tingling or shooting pain into the hand or forearm. The median nerve has two terminal branches (lateral and medial) that supply the skin of the hand. Therefore, there is often tingling (paresthesia), absence of tactile sensation (anesthesia), or diminished sensation (hypoesthesia) in the digits. Often there is a progressive loss of coordination and strength in the thumb, owing to weakness of the abductor pollicis brevis and opponens pollicis muscles. This results in difficulty in performing fine movements of the thumb. As the thenar muscles and the two lateral lumbrical muscles of the other digits are also supplied by the median nerve, the usefulness of the first to third digits may be diminished. In severe CTS cases, wasting or atrophy of the thenar muscles will occur. If the pathologic condition persists, all the tendons will die owing to ischemia.

In most people, a minor tenosynovitis of the tendons within the carpal tunnel can occur without experiencing any CTS symptoms.

Early and proper treatment can relieve pain and numbness and usually can prevent permanent damage to the wrist and hand. Permanent nerve, tendon, and muscle damage will occur if CTS is left untreated.

The efficacy of acupuncture in treating CTS depends on the severity of the condition, the nature of the case, and the general health of the patient. For example, better and faster results are achieved in patients who are suffering from the initial stages of CTS in one hand than in those who are affected in both hands. Acute and recently developed CTS is more responsive to acupuncture needling than chronic CTS in one or both hands. If the CTS is caused by carpal bone dislocation or rheumatoid thickening of the sheath as opposed to inflammation or infection, acupuncture efficacy will be uncertain. Acupuncture may help in reducing some pain, but the major symptoms can be reduced only after the carpal bone dislocation is corrected or the pressure from the rheumatoid thickening of the sheath can be released.

Ulnar Nerve Entrapment: Thoracic Outlet Syndrome

When the lower trunk of the brachial plexus passes over the first rib, the nerve trunks and subclavian blood vessels may be compressed by the scalenus anticus or medius muscles. This nerve compression produces an aching pain in the neck and along the distribution of the ulnar nerve in the forearm and hand, as well as some numbness in the little and ring fingers. Arterial compression may cause severe ischemia of the upper limb, and venous compression results in sudden pain, cyanosis, and swelling of the upper arms. If the condition persists, it results in weakness and wasting of the small muscles of the hand.

Needling scalenus muscles on the side of the neck and the upper limb helps to reduce the compression on the nerve trunks of the brachial plexus and subclavian blood vessels. This helps reduce the pain and restore the blood circulation. Other modalities such as physical therapy are also recommended.

Tenosynovitis

Long tendons run through the hand and into each finger. Each tendon is enclosed within a sheath lined with a membrane called the synovium. This membrane secretes fluid to lubricate the tendon sheaths and the joints, and to nourish the joint cartilage. The tendon sheath keeps the tendon from adhering to other tissue.

Repetitive overuse, forced activity such as in the fingers of a mountain climber, or arthritis may cause the sheath to become inflamed or infected. This condition is called tenosynovitis. Tenosynovitis can occur in the bicipital tendon in the shoulder, wrist, hand, or fingers.

The major symptoms of tenosynovitis are pain and tenderness or pain when moving the affected region, movements accompanied by a crackling sound or feeling, and hot and inflamed joint(s).

Needling of the affected region is very helpful in treating tenosynovitis, especially in the early stage of the condition because the inflammation and other symptoms are localized. The needling improves blood circulation and activates a local immune reaction to reduce the inflammation and promote healing. Once the sheath becomes thickened, needling cannot reverse the condition but may slow down the progress.

Joint and Bone Pain

Upper limb joint and bone pain are common complaints presented by patients who seek acupuncture treatments. Some patients present with acute symptoms but most cases are chronic. The following is a description of the most common conditions seen in an acupuncture clinic.

Homeostatic Acupoints

All homeostatic acupoints accessible in the position the patient uses for treatment (supine, prone, or side) should be needled.

Paravertebral Acupoints

Paravertebral acupoints can be selected from C2 to T7 because all upper limb pain and disorders are related to or derived from either the cervical plexus (C1-C4) or the brachial plexus (C5-T1). The practitioner should carefully palpate the neck and upper back to find the more sensitive region and to select the corresponding segments of the spine from C2 to T7.

Symptomatic Acupoints

Figures 10-30 through 10-33 show some of the typical symptomatic acupoints used for upper limb pain and disorders. Careful palpation should be applied to find these local symptomatic acupoints. Figures 10-30 through 10-33 also show some of the needling methods. With a good understanding of anatomical structure and mechanical function, practitioners can explore more effective needling methods for each particular case.

Figure 10-31 Supine position with arm abduction and forearm 90-degree upward flexion. Needles are inserted into the tender points in rotator cuff muscles, latissimus dorsi, pectoralis muscles, and the medial elbow.

Figure 10-32 Treatment of carpal tunnel syndrome. Needles are inserted into the median nerve point and into the carpal tunnel.

Figure 10-33 Method for needling the acupoints without puncturing the tissues or organs underneath. This photo shows how to needle H3 spinal accessory without inserting needle into the lung tissue below the trapezius muscle.