Ruptured Biceps Tendon-The Popeye Muscle

Rupture of the proximal head of the biceps tendon involves one of two heads of the biceps tendon. This condition usually occurs in older individuals and is caused by degenerative changes.

Symptoms are

• Sudden pain
• Audible snap i
• Bulge in their arm at the biceps muscle also referred to as a “Popeye Muscle”

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Various muscles and ligaments attach on scapula that are used to stabilize and move the bone. Movement of scapula helps in movements of shoulder joint.

Muscles

1. The subscapularis arises from the medial two thirds of the subscapular fossa.
2. The serratus anterior is inserted along the medial border of the costal surface-one digitations to the superior angle, two digitations to the medial border, and five digitations to the inferior angle.
3. The supraspinatus arises from the medial two thirds of the supraspinous fossa (including the upper surface of the spine).
4. The infraspinatus arises from the medial two thirds of the infraspinous fossa (including the lower surface of the spine).
5. The deltoid arises from the lower border of the crest of the spine and from the lateral border of the acromion.
6. The trapezius is inserted into the upper border of the crest of the spine and into the medial border of the acromion.
7. The long head of the biceps arises from the supraglenoid tubercle; and the short head from the lateral part of the tip of the coracoid process.
8. The coracobrachialis arises from the medial part of the tip of the coracoid process.
9. The pectoralis minor is inserted into the medial border and superior surface of the coracoid process.
10. The long head of the triceps arises from the infraglenoid tubercle.
11. The teres minor arises from the upper two thirds of the rough strip on the dorsal surface along the lateral border.
12. The teres major arises from the lower one third of the rough strip on the lateral aspect of the lateral border.
13. The levator scapulae is inserted along the dorsal aspect of the media border, from the superior angle up to the root of the spine.
14. The rhomboideus minor is inserted into the medial border (dorsal aspect) opposite the root of the spine.
15. The rhomboideus major is inserted into the medial border (dorsal aspect) between the root of the spine and the inferior angle.
16. The inferior belly of the omohyoid arises from the upper border near the suprascapular notch.

Ligaments

1. The margin of the glenoid cavity gives attachment to the capsule of the shoulder joint and to the glenoid labrum.
2. The margin of the facet on the medial aspect of the acromion gives attachment to the capsule of the acromioclavicular joint.
3. The coracoacromial ligament is attached
   1. To the lateral border of the coracoid process, and
   2. To the medial side of the tip of the acromion process.
4. The coracohumeral ligament is attached to the root of the coracoid process.
5. The coracoclavicular ligament is attached to the coracoid process: the trapezoid part on the superior aspect, and the conoid part near the root.
6. The suprascapular ligament bridges across the suprascapular notch and converts it into a foramen which transmits the suprascapular nerve. The suprascapular vessels lie above the ligament.
7. The spinoglenoid ligament bridges the spino-glenoid notch. The suprascapular vessels and nerve pass deep to it.

Clinical Features

1. Paralysis of the serratus anterior cause ‘winging’ of the scapula. The medial border of the bone becomes unduly prominent, and the arm cannot be abducted.
2. In a developmental anomaly called scaphoid scapula, the medial border is concave.

Text adapted from: Human Anatomy by BD Chaurasia

Image Credit: Wikipedia

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1. Muscles and Ligaments of Humerus
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Scapula is bone of shoulder girdle. It serves as connection between upper limb and clavicle. Its acromion process articulates with clavicle at lateral end of clavicle to form acromioclavicular joint. It also forms glenohumeral joint, popularly known as shoulder joint through its glenoid cavity with head of humerus. It has two surfaces, three borders, three angles and three processes.

The surfaces

1. The costal surface ( that abuts thorax) is concave and is directed medially and forwards. It is marked by three longitudinal ridges. Another thick ridge adjoins the lateral border. This part of the bone is almost rod like: it acts as a lever for the action of the serratus anterior in overhead abduction of the arm.
2. The dorsal ( that can be palpated from back) surface gives attachment to the spine of the scapula which divides the surface into a smaller supraspinous fossa and a larger infraspinous fossa. The two fossae are connected by the spinoglenoid notch, situated lateral to the root of the spine.

The borders

1. The superior border is thin and short. Near the root of the coracoids process it presents the suprascapular notch.
2. The lateral border is thick. At the upper end it presents the infraglenoid tubercle.
3. The medial border is thin. It extends from the superior angle to the inferior angle.

The angles

1. The superior angle is covered by the trapezius.
2. The inferior angle is covered by the latissimus dorsi. It moves forward round the chest when the arm is abducted.
3. The lateral (or glenoid) angle is broad and bears the glenoid cavity (or fossa) which is directed forwards, laterally and slightly upwards.

The processes

1. The spine (or spinous process) is triangular plate of bone with three borders and 2 surfaces. It divides the dorsal surface of the scapula into the supraspinous and infraspinous fossae. Its posterior border is called the crest of the spine. The crest has upper and lower lips.
2. The acromion has two borders, medial and lateral; two surfaces, superior and inferior, and a facet for the clavicle.
3. The coracoids process is directed forwards and slightly laterally.

Determination of the side

1. The lateral (glenoid) angle is large and bears the glenoid cavity.
2. The dorsal surface is convex and is divided by the triangular spine into the supraspinous and infraspinous fossae. The costal surface is concave to fit on the convex chest wall.
3. The lateral thickest border runs from teh glenoid cavity above to the inferior angle below.

Scapula is usually fractured in trauma around shoulder. Usually it responds very well to conservative mode of treatments.

Text adapted from: Human Anatomy by BD Chaurasia

Image Credit: Wikipedia

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Clavicle of right side viewed from below (left image) and from above(right image)

The clavicle is a long bone that connects trunk with upper limb. It is also known as collar bone. Its main function is support of the shoulder and transmittal of upper limb weight to the trunk  through the sternum.

Clavicle canbe divided into  a cylindrical part called the shaft, and two ends – medial and lateral.

The lateral end is also called  acromial end and is flat from above downwards. It  articulates with the acromion process of the scapula through a facet. The articular surface for the acromioclavicualr joint gives attachment to the joint capsule.

The medial end is called sternal end, is quadrangular in shape. This part  articulates with the clavicular notch of the manubrium sterni to form the sternoclavicular joint.  It also articulates with first costal cartilage via extension of the articular surface. The articular surface for the sternum gives attachement to the fibrous capsule all round, to the articular disc posterosuperiroly; and  to the interclavicular ligament superiorly.

The shaft of the clavicle can be divided into the lateral one third and the medial two thirds.

The lateral one third of the shaft is flattened from above downwards. It has two borders, anterior  which is concave anteriorly and  posterior which is convex posteriorly. Between the two borders are two surfaces- the superior surface and inferior surface.  While the superior surface is subcutaneous, the inferior surface has  elevation called the conoid tubercle and a ridge called the trapezoid ridge.The anterior border gives origin to the deltoid muscle and  the posterior border provides insertion to the trapezius muscle. The conoid tubercule and trapezoid ridge give attachment to the conoid and trapezoid parts of the coracoclavicular ligament.

The medial two thirds of the shaft of the clavicle is rounded and has four surfaces.

• The anterior surface- It is convex forwards.
• The posterior surface- It is thickened and smooth.
• The superior surface- This surface iss rough in its medial part.
• The inferior surface- It has a rough oval impression at the medial end. It harbors a longtitudinal groove called subclavian groove in its lateral half.

The anterior surface gives origin to the pectoralis major. The rough superior surface gives origin to the clavicular head of the sternocleidomastoid. The oval impression on the inferior surface gives attachment to the costoclavicular ligament. The subclavian groove gives insertion to the subclavius muscle and the margins of the groove give attachment to the clavipectoral fascia.

Determination of Side.

• The lateral end is flat, and the medial end is large and quadrilateral.
• The shaft is slightly curved, so that it is convex forwards in its medial 2/3, and concave forwards in its lateral 1/3.
• The inferior surface is grooved longitudinally in its middle 1/3.

Gender Variations

Female  clavicle is shorter, lighter, thinner, smoother, and less curved than in males . The lateral end of the clavicle is a little below the medial end in females whereas In males, the lateral end is either at the same level or slightly higher than the medial end.

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In this section we would have a brief outline of bones that are part of upper limb.

As we noted before upper limb starts at shoulder girdle and ends in hand. Below the external contours is hidden a complex skeletal framework that provides shape, support and mobility to upper limb. Upper limb has been highly modified in humans to enable the superior reach and grasp.

In this article we would just touch the bones briefly. Each bone would be discussed in detail separately.

Clavicle: Clavicle is the bone that connects shoulder girdle to thorax. On one side it articultes with sternum at sternoclavicular joint and on other side it articulates with acromion process of scapula at acromioclavicular joint

Scapula: Scapula has a complex anatomy and is responsible for providing overhead movements to human shoulder. It articulates with clavicle on one side. On other side it also articulates with shoulder through its glenoid cavity, a cavity that forms a joint with head of humerus called shoulder joint or scapulo-humeral joint). It also has a gliding motion with thorax at its inner surface. This gliding action adds to mobility of shoulder joint.

Humerus: Arm is formed by single bone called humerus. On upper end it forms shoulder joint and lower end it forms elbow joint by articulation with ulna.

Forearm: Forearm contains two bones-radius and ulna. Ulna forms elbow joint with lower end of humerus. Radius and ulna articluate with each other at superior and inferior radio-ulnar joints. These joints allow movements of pronation and supination.

Wrist: Wrist or carpus is formed by 8 bones which articulate with radius and ulna on one side and provide articulation to carpometacarpal joints on other side.

Hand: Hand originates at wrist as five metacarpal bones. These can be felt in region of hand that is occupied by palm. Phalanges are small bones that form skeleton of fingers and thumb. There are total of 14 phalanges, two for the thumb, and three for each finger.The phalanx that articulates with metacarpal bone is called proximal phalanx. The terminal phalanx is called distal phalanx. Thum contains only these two phalanges. A third phalanx called middle phalanx. Phalanges articulate with each other at interphalangeal joints.

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The upper and lower limbs were evolved basically for bearing the weight of the body and for locomotion. In quadrupedsforelimbs and hindlimbsairs of limbs are, therefore, built on the same basic pattern.

Each limb is made up of a basal segment or girdle, and a free part divided into proximal, middle and distal segments. The girdle attaches the limb to the axial skeleton. The distal segment carries the five digits.

Following table will elicit the similarity between two limbs

However, with the evolution of the erect posture in man, the function of weight bearing was taken over entirely by the lower limbs. As a result of this the upper limbs and hands became free and gradually evolved into organs having great manipulative skill. This has become possible because of a wide range of mobility at the shoulder.The whole upper limb works as a jointed lever.

The human hand is a grasping tool. It is exquisitely adaptable to perform various complex function.

Parts of the upper limb

1. Shoulder Region
2. Arm (or brachium)
3. Forearm (or antebrachium)
4. Hand (or manus).

Shoulder Region

Shoulder region consists of following

• The pectoral or breast region, on the front of the chest
• The axilla or armpit
• The scapular region on the back comprising parts around the scapula. The bones of the shoulder girdle are the clavicle and the scapula.

The Arm (upper arm or brachium)

Arm extends from the shoulder to the elbow (or cubitus). The bone of the arm is the humerus. Its upper end meets the scapula and from the shoulder joint. The shoulder joint permits movements of the arm.

The Forearm (antebrachium)

Forearm extends from the elbow to the wrist. The bones of the forearm are the radius and the ulna. At their upper ends they meet the lower end of the humerus to form the elbow joint. Their lower ends meet the carpal bones to form the wrist joiont.  The elbow joint permits movements of the forearm, namely flexion and extension. The radioulnar joints permit rotatory movements of the forearm called pronation and supination.

The hand (manus)

Hand includes

• The wrist or carpus
• The hand proper or metacarpus
• Five digits

The carpal bones form the wrist joint with the radius, intercarpal joints with one another, and carpometacarpal joints with the metacarpals. The phalanges form metacarpophalangeal joints with the metacarpals, and interphalangeal joints with one another. Movements of the hand are permitted chiefly at the wrist joint. The thumb moves at the first carpometacarpal joint and each finger at its metacarpophalangeal joint.

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