yeditepeanatomy1.files.wordpress.com · Web viewUnlike the lower limb, which is used for support,...

BONES & JOINTS OF

THE UPPER LIMB

30 10. 2012

Kaan YücelM.D., Ph.D.

http://yeditepeanatomy1.org

A TOTAL OF 24 FIGURES IN THE TEXT

Dr.Kaan Yücel http://yeditepeanatomy1.org Bones & joints of the upper limb

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BONES OF THE UPPER LIMBThe upper limb is characterized by its mobility and ability to conduct fine motor skills (manipulation).

These characteristics are especially marked in the hand. One of the major functions of the hand is to grip and manipulate objects. Based on the position of its major joints and component bones, the upper limb is divided into shoulder, arm, forearm, and hand for precise description.

The superior appendicular skeleton articulates with the axial skeleton only at the sternoclavicular joint, allowing great mobility. The clavicles and scapulae of the pectoral girdle are supported, stabilized, and moved by axioappendicular muscles that attach to the relatively fixed ribs, sternum, and vertebrae of the axial skeleton.

The clavicle is the only bony attachment between the trunk and the upper limb. The medial end is called “sternal end". The lateral end is called “acromial” end”.

The scapula lies on the posterolateral aspect of the thorax. It has medial, lateral, and superior borders and superior, lateral, and inferior angles. The posterior surface of the scapula is unevenly divided by spine of the scapula, into a small supraspinous fossa and a much larger infraspinous fossa. The spine continues laterally as the flat expanded acromion, which forms the subcutaneous point of the shoulder and articulates with the acromial end of the clavicle. The concave costal surface of most of the scapula forms a large subscapular fossa.

The skeletal support for the arm is the humerus. The humerus (arm bone) articulates with the scapula at the glenohumeral joint and the radius and ulna at the elbow joint. The proximal end of the humerus has a head, surgical and anatomical necks, and greater and lesser tubercles. The distal end of the humerus has a condyle, two epicondyles, and three fossae.

Ulna is the medial and longer of the two forearm bones.It is the stabilizing bone of the forearm. Radius is the lateral and shorter of the two forearm bones.

The hand is the region of the upper limb distal to the wrist joint. It is subdivided into three parts: wrist, (carpus); metacarpus; digits (five fingers including the thumb).

JOINTS OF THE UPPER LIMBMovement of the pectoral girdle involves the sternoclavicular, acromioclavicular, and glenohumeral joints,

usually all moving simultaneously. Functional defects in any of the joints impair movements of the pectoral girdle. Mobility of the scapula is essential for free movement of the upper limb. The clavicle forms a strut that holds the scapula, and hence the glenohumeral joint, away from the thorax so it can move freely.Sternoclavicular joint: the only articulation between the upper limb and the axial skeleton. The sternal end of the clavicle articulates with the manubrium and a small part of the 1st costal cartilage. Saddle type, but functions as a ball-and-socket joint.Acromioclavicular joint: The acromial end of the clavicle articulates with the acromion of the scapula. Plane type. Glenohumeral (Shoulder) joint: More freedom of movement than any other joint in the body. Humeral head articulates with the relatively shallow glenoid cavity of the scapula, which is deepened slightly but effectively by the glenoid labrum (L., lip). Ball-and-socket type of synovial joint.Elbow joint: The spool-shaped trochlea and spheroidal capitulum of the humerus articulate with the trochlear notch of the ulna and the slightly concave superior aspect of the head of the radius, respectively; therefore, there are humeroulnar and humeroradial articulations. Hinge typeProximal (Superior) radio-ulnar joint: The head of the radius articulates with the radial notch of the ulna. Pivot type.Distal (Inferior) radio-ulnar joint: The head of the ulna articulates with the ulnar notch on the medial side of the distal end of the radius.Pivot type.Wrist (Radiocarpal) joint: The wrist (carpus), the proximal segment of the hand, is a complex of eight carpal bones, articulating proximally with the forearm via the wrist joint and distally with the five metacarpals. The ulna does not participate in the wrist joint. The distal end of the radius and the articular disc of the distal radio-ulnar joint articulate with the proximal row of carpal bones, except for the pisiform. Condyloid (ellipsoid) type.Intercarpal joints: Carpal bones (the intercarpal joints interconnect the carpal bones). Plante type.Carpometacarpal joints: The distal surfaces of the carpals of the distal row articulate with the carpal surfaces of the bases of the metacarpals. The important carpometacarpal joint of the thumb is between the trapezium and the base of the 1st metacarpal; it has a separate articular cavity. Like the carpals, adjacent metacarpals articulate with each other. The carpometacarpal and intermetacarpal joints are the plane type of synovial joint, except for the carpometacarpal joint of the thumb, which is a saddle joint. The metacarpophalangeal joints are the condyloid type of synovial joint that permit movement in two planes: flexion-extension and adduction-abduction. The interphalangeal joints are the hinge type of synovial joint that permit flexion-extension only.The heads of the metacarpals articulate with the bases of the proximal phalanges, and the heads of the phalanges articulate with the

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The upper limb is characterized by its mobility and ability to conduct fine motor skills (manipulation).

These characteristics are especially marked in the hand. One of the major functions of the hand is to grip and

manipulate objects. Efficiency of hand function results in large part from the ability to place it in the proper

position by movements at the scapulothoracic, glenohumeral, elbow, radio-ulnar, and wrist joints.

Unlike the lower limb, which is used for support, stability, and locomotion, the upper limb is highly

mobile for positioning the hand in space.

The upper limb is associated with the lateral aspect of the lower portion of the neck and with the

thoracic wall. It is suspended from the trunk by muscles and a small skeletal articulation between the clavicle

and the sternum: the sternoclavicular joint. Based on the position of its major joints and component bones,

the upper limb is divided into shoulder, arm, forearm, and hand for precise description:

• Shoulder: is the proximal segment of the limb and the area of upper limb attachment to the trunk. The

pectoral (shoulder) girdle is a bony ring, incomplete posteriorly, formed by the scapulae and clavicles and

completed anteriorly by the manubrium of the sternum (part of the axial skeleton).

• Arm (L. brachium): first segment of the free upper limb (more mobile part of the upper limb independent

of the trunk) and the longest segment of the limb. The arm is the part of the upper limb between the

shoulder and the elbow joint. It extends between and connects the shoulder and the elbow and consists of

anterior and posterior regions of the arm, centered around the humerus.

• Forearm (L. antebrachium): second longest segment of the limb. The forearm is between the elbow joint

and the wrist joint. The forearm includes anterior and posterior regions of the forearm overlying the radius

and ulna.

• Hand (L. manus): is the part of the upper limb distal to the forearm. The hand is formed around the

carpus, metacarpus, and phalanges. It is composed of the wrist, palm, dorsum of hand, and digits (fingers,

including an opposable thumb).

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1. UPPER LIMB


Figure 1. Regions of the body and the upper limbhttp://psychology.wikia.com/wiki/Mouth_(human)

The pectoral girdle and bones of the free part of the upper limb form the superior appendicular

skeleton; the pelvic girdle and bones of the free part of the lower limb form the inferior appendicular

skeleton. The superior appendicular skeleton articulates with the axial skeleton only at the sternoclavicular

joint, allowing great mobility. The clavicles and scapulae of the pectoral girdle are supported, stabilized, and

moved by axioappendicular muscles that attach to the relatively fixed ribs, sternum, and vertebrae of the

axial skeleton.

Figure 2. Bones of the upper limbhttps://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcSW8LslcjBie9q3v6c-iF5_yVmA8HzibdIxevO5SvdpHeTI8MDa

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2. BONES OF THE UPPER LIMB

3. BONES OF THE PECTORAL GIRDLE

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http://psychology.wikia.com/wiki/Mouth_(human)


3.1. CLAVICLE (COLLAR BONE)The clavicle is the only bony attachment between the trunk and the upper limb. It is palpable along

its entire length and has a gentle S-shaped contour, with the forward-facing convex part medial and the

forward-facing concave part lateral.

The medial end is called “sternal end". The sternal end is enlarged and triangular where it articulates with

the manubrium of the sternum at the sternoclavicular joint.

The lateral end is called “acromial” end”. The acromial end is flat where it articulates with the acromion of

the scapula at the acromioclavicular joint.

Figure 3. The location of the claviclehttp://www.daviddarling.info/images/clavicle.gif

The medial two thirds of the shaft of the clavicle are convex anteriorly, whereas the lateral third is flattened

and concave anteriorly. These curvatures increase the resilience of the clavicle and give it the appearance of

an elongated capital S.

Although designated as a long bone, the clavicle has no medullary (marrow) cavity. It consists of spongy

(trabecular) bone with a shell of compact bone.

The inferior surface of the clavicle is rough because strong ligaments bind it to the 1st rib near its

sternal end and suspend the scapula from its acromial end. The conoid tubercle, near the acromial end of

the clavicle, gives attachment to the conoid ligament, the medial part of the coracoclavicular ligament. Also,

near the acromial end of the clavicle is the trapezoid line, to which the trapezoid ligament attaches; it is the

lateral part of the coracoclavicular ligament.

The subclavian groove (groove for the subclavius) in the medial third of the shaft of the clavicle is the

site of attachment of the subclavius muscle. More medially is the impression for the costoclavicular

ligament, a rough, often depressed, oval area that gives attachment to the ligament binding the 1st rib (L.

costa) to the clavicle, limiting elevation of the shoulder.


http://www.daviddarling.info/images/clavicle.gif


Functions of the clavicle:

• Serves as a moveable, rigid support from which the scapula and free limb are suspended, keeping them

away from the trunk so that the limb has maximum freedom of motion. The support formed by the clavicle

is movable and allows the scapula to move on the thoracic wall at the “scapulothoracic joint,” increasing the

range of motion of the limb. Fixing the point of the support in position, especially after its elevation, enables

elevation of the ribs for deep inspiration.

• Forms one of the bony boundaries of the cervico-axillary canal (passageway between the neck and the

arm), affording protection to the neurovascular bundle supplying the upper limb.

• Transmits shocks (traumatic impacts) from the upper limb to the axial skeleton.

Figure 4. Claviclehttp://medchrome.com/basic-science/anatomy/clavicle

3.2. SCAPULA (SHOULDER BLADE)The scapula is a large, flat triangular bone which lies on the posterolateral aspect of the thorax,

overlying the 2nd-7th ribs with:

three angles (lateral, superior, and inferior)

three borders (superior, lateral, and medial)

two surfaces (costal and posterior)

three processes (acromion, spine, and coracoid process)

The scapula has medial, lateral, and superior borders and superior, lateral, and inferior angles.

Borders (margins) of the scapula


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Medial border: When the scapular body is in the anatomical position, the thin medial border of the scapula

runs parallel to and approximately 5 cm lateral to the spinous processes of the thoracic vertebrae; hence it is

often called the vertebral border.

Lateral border: From the inferior angle, the lateral border of the scapula runs superolaterally toward the

apex of the axilla; hence it is often called the axillary border. The lateral border is made up of a thick bar of

bone that prevents buckling of this stressbearing region of the scapula.The lateral border terminates in the

truncated lateral angle of the scapula, the thickest part of the bone that bears the broadened head of the

scapula. The glenoid cavity is the primary feature of the head. The shallow constriction between the head

and the body defines the neck of the scapula.

Superior border: is marked near the junction of its medial two thirds and lateral third by the suprascapular

notch. The suprascapular notch is located where the superior border joins the base of the coracoid process.

The superior border is the thinnest and shortest of the three borders.

The scapula is capable of considerable movement on the thoracic wall at the physiological

scapulothoracic joint, providing the base from which the upper limb operates.

Posterior surface of the scapulaAcromionDeltoid tubercle of the scapular spineSpine of the scapulaSupraspinous and infraspinous fossae

The convex posterior surface of the scapula is unevenly divided by a thick projecting ridge of bone;

spine of the scapula, into a small supraspinous fossa and a much larger infraspinous fossa. The spine

continues laterally as the flat expanded acromion (G. akros, point), which forms the subcutaneous point of

the shoulder and articulates with the acromial end of the clavicle. The deltoid tubercle of the scapular spine

is the prominence indicating the medial point of attachment of the deltoid. The spine and acromion serve as

levers for the attached muscles, particularly the trapezius.

Anterior (Costal) surface of the scapulaSubscapular fossaThe concave costal surface of most of the scapula forms a large subscapular fossa. The broad bony surfaces

of the three fossae provide attachments for fleshy muscles.

Lateral surface of the scapulaCoracoid processFossa ovalis



Glenoid cavitySuperolaterally, the lateral surface of the scapula has a glenoid cavity (G. socket), which receives and

articulates with the head of the humerus at the glenohumeral joint. The glenoid cavity is a shallow, concave,

oval fossa (L. fossa ovalis), directed anterolaterally and slightly superiorly—that is considerably smaller than

the ball (head of the humerus) for which it serves as a socket. The beak-like coracoid process (G. korakōdés,

like a crow's beak) is superior to the glenoid cavity and projects anterolaterally. This process also resembles

in size, shape, and direction a bent finger pointing to the shoulder.

Figure 5. Scapula and the shoulder jointhttp://therapyworksltd.files.wordpress.com/2012/07/shoulder.jpg

Figure 6. Scapula- costal surface, lateral view, and posterior surfacehttp://conornordengren.com/2011/10/14/the-shoulder-girdle-part-1-bones-and-joints-2

Fractures of the Clavicle


CLINICAL ANATOMY

http://conornordengren.com/2011/10/14/the-shoulder-girdle-part-1-bones-and-joints-2/

http://therapyworksltd.files.wordpress.com/2012/07/shoulder.jpg


The clavicle is one of the most frequently fractured bones. Clavicular fractures are especially common

in children and are often caused by an indirect force transmitted from an outstretched hand through the

bones of the forearm and arm to the shoulder during a fall. A fracture may also result from a fall directly on

the shoulder. The weakest part of the clavicle is the junction of its middle and lateral thirds.

Fractures of the ScapulaFracture of the scapula is usually the result of severe trauma, as occurs in pedestrian-vehicle

accidents. Usually there are also fractured ribs. Most fractures require little treatment because the scapula is

covered on both sides by muscles.

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4.1. HUMERUS (ARM BONE)the largest bone in the upper limb

The skeletal support for the arm is the humerus. The humerus (arm bone) articulates with the

scapula at the glenohumeral joint and the radius and ulna at the elbow joint.

In cross-section, the shaft of the humerus is somewhat triangular with:

anterior, lateral, and medial borders

anterolateral, anteromedial, and posterior surfaces

Intermuscular septa, which separate the anterior compartment from the posterior compartment, attach to

the medial and lateral borders.

Proximal end of the humerusAnatomical neck of the humerusGreater & lesser tuberclesHead of the humerusIntertubercular (bicipital) grooveSurgical neck of the humerus

The proximal end of the humerus has a head, surgical and anatomical necks, and greater and lesser

tubercles. The spherical head of the humerus articulates with the glenoid cavity of the scapula. The

anatomical neck of the humerus is formed by the groove circumscribing the head and separating it from the

greater and lesser tubercles. It indicates the line of attachment of the glenohumeral joint capsule. The

surgical neck of the humerus, a common site of fracture, is the narrow part distal to the head and tubercles.


4. BONE OF THE ARM


The junction of the head and neck with the shaft of the humerus is indicated by the greater and lesser

tubercles, which provide attachment and leverage to some scapulohumeral muscles. The greater tubercle is

at the lateral margin of the humerus, whereas the lesser tubercle projects anteriorly from the bone. The

intertubercular (bicipital) groove separates the tubercles.

Shaft of the humerusDeltoid tuberosityMedial and lateral supraepicondylar (supracondylar) ridgesRadial grooveThe shaft of the humerus has two prominent features: the deltoid tuberosity laterally, for attachment of the

deltoid muscle, and the oblique radial groove (groove for radial nerve, spiral groove) posteriorly.

Distally, the bone becomes flattened, and the medial and lateral borders expand inferiorly as the lateral

supraepicondylar ridge (lateral supracondylar ridge) and the medial supraepicondylar ridge (medial

supracondylar ridge). The lateral supraepicondylar ridge is more pronounced than the medial and is

roughened for the attachment of muscles found in the posterior compartment of the forearm.

Distal end of the humerusCondyle of the humerus; Trochlea+Capitulum Coronoid fossaMedial and lateral epicondylesOlecranon fossaThe distal end of the humerus has a condyle, two epicondyles, and three fossae:

Condyle

The two articular parts of the condyle, the capitulum and the trochlea, articulate with the two bones of the

forearm.

Capitulum (L. little head) articulates with the radius of the forearm. Lateral in position and hemispherical in

shape, is not visible when the humerus is viewed from the posterior aspect.

Trochlea (L. pulley) articulates with the ulna of the forearm. It is pulley shaped and lies medial to the

capitulum. Its medial edge is more pronounced than its lateral edge and, unlike the capitulum, it extends

onto the posterior surface of the bone.

Epicondyles

The two epicondyles lie adjacent, and somewhat superior, to the trochlea and capitulum.

The medial epicondyle, a large bony protuberance, is the major palpable landmark on the medial side of the

elbow, and projects medially from the distal end of the humerus. It is the attachment site for the muscles of

the anterior (flexor) compartment of the forearm.



The lateral epicondyle is much less pronounced than the medial epicondyle. It is lateral to the capitulum and

the attachment site for the muscles of the posterior (extensor) compartment of the forearm.

Fossae

Coronoid fossa adjacent to the radial fossa superior to the trochlea. It receives the coronoid process of the

ulna during full flexion of the elbow.

Olecranon fossa largest fossa, immediately superior to the trochlea on the posterior surface of the distal

end of the humerus. It accommodates the olecranon of the ulna during full extension of the elbow.

Radial fossa a shallow fossa immediately superior to the capitulum on the anterior surface of the humerus.

It accommodates the edge of the head of the radius when the forearm is fully flexed.

Figure 7. Humerus Figure 8. Distal end of the humerushttp://www.edoctoronline.com/medical-atlas.asp?c=4&id=22082 http://www.medpreponline.com/2009/06/supracondylar-fractures-of-humerus-in.html

Fractures of the humerus


CLINICAL ANATOMY

http://www.medpreponline.com/2009/06/supracondylar-fractures-of-humerus-in.html

http://www.edoctoronline.com/medical-atlas.asp?c=4&id=22082


Most injuries of the proximal end of the humerus are fractures of the surgical neck. These injuries are

especially common in elderly people with osteoporosis. The injuries usually result from a minor fall on the

hand, with the force being transmitted up the forearm bones of the extended limb.

The two forearm bones serve together to form the second unit of an articulated mobile strut (the

first unit being the humerus), with a mobile base formed by the shoulder, that positions the hand. However,

because this unit is formed by two parallel bones, one of which (the radius) can pivot about the other (the

ulna), supination and pronation are possible. This makes it possible to rotate the hand when the elbow is

flexed.

5.1. ULNAmedial and longer of the two forearm bones

The ulna is the stabilizing bone of the forearm.

Proximal end of the ulnaCoronoid process OlecranonRadial notchTrochlear notch (Semilunar notch)Tuberosity of the ulnaThe proximal end of the ulna is larger than the proximal end of the radius. This end is specialized for

articulation with the humerus proximally and the head of the radius laterally. For articulation with the

humerus, the ulna has two prominent projections:

1) Olecranon projects proximally from its posterior aspect (forming the tip of the elbow) and serves as a

short lever for extension of the elbow.

2) Coronoid process projects anteriorly. Its superolateral surface is articular and participates, with the

olecranon, in forming the trochlear notch. The lateral surface is marked by a smooth rounded cavity; radial

notch for articulation with the head of the radius.

Inferior to the coronoid process is the tuberosity of the ulna.

The olecranon and coronoid processes form the walls of the trochlear notch (semilunar notch). The

trochlear in profile resembles the jaws of a Crescent wrench as it “grips” (articulates with) the trochlea of

the humerus.

Shaft of the ulnaSupinator crest Supinator fossa


5. BONES OF THE FOREARM


The shaft of the ulna is broad superiorly where it is continuous with the large proximal end and narrow

distally to form a small distal head. The shaft of the ulna is triangular in cross-section and has:

three borders (anterior, posterior, and interosseous)

three surfaces (anterior, posterior, and medial).

The anterior border is smooth and rounded. The posterior border is sharp and palpable along its entire

length. The interosseous border is also sharp and is the attachment site for the interosseous membrane,

which joins the ulna to the radius.

Inferior to the radial notch on the lateral surface of the ulnar shaft is a prominent ridge, the supinator crest.

On the lateral surface of proximal end of ulna, just below the radial notch is a concavity, the supinator fossa.

Distal end of the ulnaHead of the ulnaUlnar styloid processAt the narrow distal end of the ulna is a small but abrupt enlargement, the disc-like head of the ulna with a

small, conical ulnar styloid process. The ulna does not reach—and therefore does not participate in—the

wrist (radiocarpal) joint.

5.2.RADIUSlateral and shorter of the two forearm bones

Proximal end of the radius A short head Neck Radial tuberosityHead of the radiusProximally, the smooth superior aspect of the discoid head of the radius is concave for articulation with the

capitulum of the humerus during flexion and extension of the elbow joint. The head also articulates

peripherally with the radial notch of the ulna; thus the head is covered with articular cartilage.

Neck of the radiusThe neck of the radius is a constriction distal to the head. The oval radial tuberosity is distal to the medial

part of the neck and demarcates the proximal end (head and neck) of the radius from the shaft. The radial

tuberosity is medially directed.

Shaft of the radiusOblique line of the radius



The shaft of the radius, in contrast to that of the ulna, gradually enlarges as it passes distally. Throughout

most of its length, like the ulna, the shaft of the radius is triangular in cross-section, with:

three borders (anterior, posterior, and interosseous)

three surfaces (anterior, posterior, and lateral).

The anterior border begins on the medial side of the bone as a continuation of the radial tuberosity. In the

superior third of the bone, it crosses the shaft diagonally, from medial to lateral, as the oblique line of the

radius. The posterior border is distinct only in the middle third of the bone. The interosseous border is sharp

and is the attachment site for the interosseous membrane, which links the radius to the ulna.

Distal end of the radius Dorsal tubercle of the radius Radial styloid process Ulnar notchThe medial aspect of the distal end of the radius forms a concavity, the ulnar notch, which accommodates

the head of the ulna. Its lateral aspect becomes increasingly ridge-like, terminating distally in the radial

styloid process. The radial styloid process is larger than the ulnar styloid process and extends farther

distally. This relationship is of clinical importance when the ulna and/or the radius is fractured.

Projecting dorsally, the dorsal tubercle of the radius lies between otherwise shallow grooves for the passage

of the tendons of forearm muscles.

The distal end of the bone is marked by two facets for articulation with two carpal bones (the scaphoid and

lunate).

Figures 9 & 10. Radius & Ulnahttp://www.bcnlp.ac.th/Anatomy/page/apichat/bone/page/ulna.html http://www.daviddarling.info/images/radius_and_ulna.jpg


http://www.daviddarling.info/images/radius_and_ulna.jpg

http://www.bcnlp.ac.th/Anatomy/page/apichat/bone/page/ulna.html


Fractures of the Radius and UlnaFractures of both the radius and the ulna are usually the result of severe injury. A direct injury usually

produces transverse fractures at the same level, usually in the middle third of the bones. Isolated fractures

of the radius or ulna also occur. Because the shafts of these bones are firmly bound together by the

interosseous membrane, a fracture of one bone is likely to be associated with dislocation of the nearest

joint.

Fracture of the distal end of the radius is a common fracture in adults > 50 years of age and occurs

more frequently in women because their bones are more commonly weakened by osteoporosis. A complete

transverse fracture of the distal 2 cm of the radius, called a Colles’ fracture, is the most common fracture of

the forearm. The distal fragment is displaced dorsally and is often comminuted (broken into pieces). The

fracture usually occurs as the result of trying to ease a fall by outstretching the upper limb. The force drives

the distal fragment posteriorly and superiorly, and the distal articular surface is inclined posteriorly. This

posterior displacement produces a posterior bump, sometimes referred to as the “dinner-fork deformity”

because the forearm and wrist resemble the shape of a fork.

Fractures of the olecranon process can result from a fall on the flexed elbow or from a direct blow.

Olecranon BursitisA small subcutaneous bursa is present over the olecranon process of the ulna, and repeated trauma

often produces chronic bursitis.


CLINICAL ANATOMY


The hand is the region of the upper limb distal to the wrist joint. It is subdivided into three parts:

wrist (carpus);

metacarpus;

digits (five fingers including the thumb).

Carpal bonesThe wrist, or carpus, is composed of eight carpal bones (carpals) arranged in proximal and distal

rows of four. These small bones give flexibility to the wrist. The carpus is markedly convex from side to side

posteriorly and concave anteriorly. Augmenting movement at the wrist joint, the two rows of carpals glide

on each other; in addition, each bone glides on those adjacent to it.

From lateral to medial, the four bones in the proximal row of carpals• Scaphoid (G. skaphé, skiff, boat): a boat-shaped bone that articulates proximally with the radius and has

a prominent scaphoid tubercle; it is the largest bone in the proximal row of carpals.

• Lunate (L. luna, moon): a crescent (or moon) -shaped bone between the scaphoid and the triquetral

bones; it articulates proximally with the radius and is broader anteriorly than posteriorly.

• Triquetrum (L. triquetrus, three-cornered): a pyramidal bone on the medial side of the carpus; it

articulates proximally with the articular disc of the distal radio-ulnar joint.

• Pisiform (L. pisum, pea): a small, pea-shaped bone that lies on the palmar surface of the triquetrum.

From lateral to medial, the four bones in the distal row of carpals• Trapezium (G. trapeze, table): a four-sided bone on the lateral side of the carpus; it articulates with the

1st and 2nd metacarpals, scaphoid, and trapezoid bones.

• Trapezoid: a wedge-shaped bone that resembles the trapezium; it articulates with the 2nd metacarpal,

trapezium, capitate, and scaphoid bones.

• Capitate (L. caput, head): a head-shaped bone with a rounded extremity and the largest bone in the

carpus; it articulates primarily with the 3rd metacarpal distally and with the trapezoid, scaphoid, lunate, and

hamate.

• Hamate (L. hamulus, a little hook): a wedge-shaped bone on the medial side of the hand; it articulates

with the 4th and 5th metacarpal, capitate, and triquetral bones; it has a distinctive hooked process, the hook

of the hamate, that extends anteriorly.

Carpal arch The carpal bones do not lie in a flat plane; rather, they form an arch, whose base is directed anteriorly. The

lateral side of this base is formed by the tubercles of the scaphoid and trapezium. The medial side is formed

by the pisiform and the hook of hamate. http://www.youtube.com/yeditepeanatomy 16

6. BONES OF THE HAND


Figure 11. Carpal boneshttp://www.daviddarling.info/encyclopedia/C/carpal.html

The proximal surfaces of the distal row of carpals articulate with the proximal row of carpals, and their

distal surfaces articulate with the metacarpals.

MetacarpusThe metacarpus forms the skeleton of the palm of the hand between the carpus and the phalanges.

It is composed of five metacarpal bones (metacarpals). Each metacarpal consists of a base, shaft, and head.

The proximal bases of the metacarpals articulate with the carpal bones, and the distal heads of the

metacarpals articulate with the proximal phalanges and form the knuckles. The 1st metacarpal (of the

thumb) is the thickest and shortest of these bones.

PhalangesEach digit has three phalanges except for the first (the thumb), which has only two; however, the

phalanges of the first digit are stouter than those in the other fingers. Each phalanx has a base proximally, a

shaft (body), and a head distally. The proximal phalanges are the largest, the middle ones are intermediate

in size, and the distal ones are the smallest.

Figure 12. Anatomy of the hand Figure 13. Bones of the handhttp://www.yalemedicalgroup.org/stw/images/125411.jpg http://www.daviddarling.info/encyclopedia/P/phalange.html


http://www.daviddarling.info/encyclopedia/P/phalange.html

http://www.yalemedicalgroup.org/stw/images/125411.jpg

http://www.daviddarling.info/encyclopedia/C/carpal.html


Injuries to the Bones of the HandThe scaphoid is the most frequently fractured carpal bone. It often results from a fall on the palm

when the hand is abducted, the fracture occurring across the narrow part of the scaphoid.

Dislocation of the lunate bone occasionally occurs in young adults who fall on the outstretched hand

in a way that causes hyperextension of the wrist joint.

Fractures of the metacarpal bones can occur as a result of direct violence, such as the clenched fist

striking a hard object. The fracture always angulates dorsally. The “boxer’s fracture” commonly produces an

oblique fracture of the neck of the fifth and sometimes the fourth metacarpal bones.

Fractures of the phalanges are common and usually follow direct injury.

Joints of the pectoral girdle

Acromioclavicular joint & Sternoclavicular joint

Glenohumeral (Shoulder) joint

Elbow joint

Proximal (Superior) and Distal (Inferior) radio-

ulnar joints

Radiocarpal (Wrist) joint

Intercarpal joints

Carpometacarpal and intermetacarpal joints

Figure 14. Joints of the upper limbhttp://home.comcast.net/~wnor/lesson5jointsofupperlimb.htm


7. JOINTS OF THE UPPER LIMB

CLINICAL ANATOMY

http://home.comcast.net/~wnor/lesson5jointsofupperlimb.htm


1. Articulation between Sternum and clavicle

2. Distinct feature of the joint the only articulation between the upper limb and the axial skeleton. It can be

readily palpated because the sternal end of the clavicle lies superior to the manubrium of the sternum.

3. Synovial joint type Saddle type, but functions as a ball-and-socket joint

4. Articular disc Yes. The articular disc divides the sternoclavicular joint into two compartments.

5. Articular surfaces The sternoclavicular joint occurs between the sternal end of the clavicle and the

clavicular notch of the manubrium of sternum together with a small part of the first costal cartilage.

6. Ligaments of the sternoclavicular joint

The sternoclavicular joint is surrounded by a joint capsule and is reinforced by four ligaments:

Anterior and posterior sternoclavicular ligamentsCostoclavicular ligamentInterclavicular ligamentThe anterior and posterior sternoclavicular ligaments are anterior and posterior, respectively, to the joint.

The interclavicular ligament links the ends of the two clavicles to each other and to the superior surface of

the manubrium of sternum.


STERNOCLAVICULAR JOINT


The costoclavicular ligament is positioned laterally to the joint and links the proximal end of the clavicle to

the first rib and related costal cartilage.

Anterior and posterior sternoclavicular ligaments reinforce the joint capsule anteriorly and

posteriorly. The interclavicular ligament strengthens the capsule superiorly. The costoclavicular ligament

anchors the inferior surface of the sternal end of the clavicle to the 1st rib and its costal cartilage, limiting

elevation of the pectoral girdle.

The strength of the sternoclavicular joint depends on ligaments and its articular disc. The disc is firmly

attached to the anterior and posterior sternoclavicular ligaments, thickenings of the fibrous layer of the joint

capsule, as well as the interclavicular ligament. The great strength of the sternoclavicular joint is a

consequence of these attachments. Thus, although the articular disc serves as a shock absorber of forces

transmitted along the clavicle from the upper limb, dislocation of the clavicle is rare, whereas fracture of the

clavicle is common.

7. Movements of the sternoclavicular joint

Raising (60°) & rotating the clavicleAnterior and posterior movements of the clavicle

The sternoclavicular joint allows movement of the clavicle, predominantly in the anteroposterior and

vertical planes, although some rotation also occurs. Although the sternoclavicular joint is extremely strong, it

is significantly mobile to allow movements of the pectoral girdle and upper limb. During full elevation of the

limb, the clavicle is raised to approximately a 60° angle. When elevation is achieved via flexion, it is

accompanied by rotation of the clavicle around its longitudinal axis.

Figure 15. Sternoclavicular jointhttp://www.daviddarling.info/encyclopedia/S/sternoclavicular_joint.html


http://www.daviddarling.info/encyclopedia/S/sternoclavicular_joint.html


Sternoclavicular Joint InjuriesThe strong costoclavicular ligament firmly holds the medial end of the clavicle to the first costal

cartilage. Violent forces directed along the long axis of the clavicle usually result in fracture of that bone, but

dislocation of the sternoclavicular joint takes place occasionally. If the costoclavicular ligament ruptures

completely, it is difficult to maintain the normal position of the clavicle once reduction has been

accomplished.

1. Articulation between Acromion of scapulae and clavicle

2. Distinct feature of the joint Located 2-3 cm from the “point” of the shoulder formed by the lateral part of

the acromion

3. Synovial joint type Plane type

4. Articular disc Yes. The articular surfaces are separated by an incomplete wedge-shaped articular disc.

5. Articular surfaces The acromial end of the clavicle articulates with the acromion of the scapula. The

articular surfaces, covered with fibrocartilage.

6. Ligaments of the acromioclavicular joint

Intrinsic ligament of the acromioclavicular joint

Acromioclavicular ligamentExtrinsic ligament of the acromioclavicular joint

Coracoclavicular ligament- conoid ligament and trapezoid ligament


ACROMIOCLAVICULAR JOINT

CLINICAL ANATOMY


The acromioclavicular ligament is a fibrous band extending from the acromion to the clavicle that

strengthens the acromioclavicular joint superiorly. However, the integrity of the joint is maintained by

extrinsic ligaments, distant from the joint itself.

The much larger coracoclavicular ligament is a strong pair of bands that unite the coracoid process of

the scapula to the clavicle, anchoring the clavicle to the coracoid process.

The coracoclavicular ligament is not directly related to the joint. However,it is an important strong

accessory ligament, providing much of the weightbearing support for the upper limb on the clavicle. It

maintains the position of the clavicle on the acromion. It spans the distance between the coracoid process of

the scapula and the inferior surface of the acromial end of the clavicle.

The coracoclavicular ligament consists of two ligaments, the conoid and trapezoid ligaments, which

are often separated by a bursa.

The vertical conoid ligament is an inverted triangle (cone), is attached to the root of the coracoid process. Its

wide attachment (base of the triangle) is to the conoid tubercle on the inferior surface of the clavicle. The

nearly horizontal trapezoid ligament is attached to the superior surface of the coracoid process and extends

laterally to the trapezoid line on the inferior surface of the clavicle.

In addition to augmenting the acromioclavicular joint, the coracoclavicular ligament provides the

means by which the scapula and free limb are (passively) suspended from the clavicular strut.

7. Movements of the acromioclavicular joint

The acromioclavicular joint allows movement in the anteroposterior and vertical planes together with

some axial rotation. The acromion of the scapula rotates on the acromial end of the clavicle. These

movements are associated with motion at the physiological scapulothoracic joint.

Figure 16. Acromioclavicular jointhttp://www.rahulgladwin.com/medimages/index.php?level=picture&id=96


CLINICAL ANATOMY

http://www.rahulgladwin.com/medimages/index.php?level=picture&id=96


Acromioclavicular Joint DislocationA severe blow on the point of the shoulder, as is incurred during blocking or tackling in football or

any severe fall, can result in the acromion being thrust beneath the lateral end of the clavicle, tearing the

coracoclavicular ligament. This condition is known as shoulder separation. The displaced outer end of the

clavicle is easily palpable.

1. Articulation between Humerus and scapula

2. Distinct feature of the joint Ball-and-socket type of synovial joint that permits a wide range of movement;

however, its mobility makes the joint relatively unstable. The glenohumeral joint has more freedom of

movement than any other joint in the body.

3. Synovial joint type Ball-and-socket type

4. Articular disc No.

5. Articular surfaces The large, round humeral head articulates with the relatively shallow glenoid cavity of

the scapula, which is deepened slightly but effectively by the ring-like, fibrocartilaginous glenoid labrum (L.,

lip). Both articular surfaces are covered with hyaline cartilage. The glenoid cavity accepts little more than a

third of the humeral head, which is held in the cavity by the tonus of the musculotendinous rotator cuff

muscles.

6. Ligaments of the glenohumeral joint

Glenohumeral ligamentsCoracohumeral ligamentTransverse humeral ligamentCoracoacromial ligamentThe fibrous membrane of the joint capsule is thickened:

Glenohumeral ligaments three fibrous bands, evident only on the internal aspect of the capsule

anterosuperiorly in three locations to form superior, middle, and inferior glenohumeral ligaments

pass from the superomedial margin of the glenoid cavity to the lesser tubercle and inferiorly related

anatomical neck of the humerus.

strengthen the anterior aspect of the joint capsule of the joint.

Coracohumeral ligament strong broad band


GLENOHUMERAL (SHOULDER) JOINT - ARTICULATIO HUMERI


passes from the base of the coracoid process to the anterior aspect of the greater tubercle of the

humerus.

strengthens the capsule superiorly.

Transverse humeral ligament a broad fibrous band

between the greater and lesser tubercles of the humerus, bridging over the intertubercular sulcus

converts the groove into a canal, which holds the synovial sheath and tendon of the biceps brachii in

place during movements of the glenohumeral joint.

The coraco-acromial arch is an extrinsic, protective structure formed by the smooth inferior aspect of

the acromion and the coracoid process of the scapula, with the coracoacromial ligament spanning between

them. This osseoligamentous structure forms a protective arch that overlies the humeral head, preventing

its superior displacement from the glenoid cavity. The coraco-acromial arch is so strong that a forceful

superior thrust of the humerus will not fracture it; the humeral shaft or clavicle fractures first.

Transmitting force superiorly along the humerus (e.g., when standing at a desk and partly supporting the

body with the outstretched limbs), the humeral head presses against the coraco-acromial arch.

Joint stability is provided by surrounding muscle tendons and a skeletal arch formed superiorly by the

coracoid process and acromion and the coracoacromial ligament.

7. Movements of the glenohumeral joint

Flexion of the humerusExtension of the humerusAbduction of the humerusAdduction of the humerusMedial and lateral rotation of the humerusCircumduction

The glenohumeral joint has more freedom of movement than any other joint in the body. This

freedom results from the laxity of its joint capsule and the large size of the humeral head compared with the

small size of the glenoid cavity. The glenohumeral joint allows movements around three axes and permits

flexion-extension, abduction-adduction, rotation (medial and lateral) of the humerus, and circumduction.

Lateral rotation of the humerus increases the range of abduction. When the arm is abducted without

rotation, available articular surface is exhausted and the greater tubercle contacts the coraco-acromial arch,

preventing further abduction. If the arm is then laterally rotated 180°, the tubercles are rotated posteriorly

and more articular surface becomes available to continue elevation.

Circumduction at the glenohumeral joint is an orderly sequence of flexion, abduction, extension, and

adduction—or the reverse. Unless performed over a small range, these movements do not occur at the http://www.youtube.com/yeditepeanatomy 24


glenohumeral joint in isolation; they are accompanied by movements at the two other joints of the pectoral

girdle (sternoclavicular and acromioclavicular joints).

8. Bursae around the glenohumeral joint

Several bursae (sac-like cavities), containing capillary films of synovial fluid secreted by the synovial

membrane, are situated near the glenohumeral joint. Bursae are located where tendons rub against bone,

ligaments, or other tendons and where skin moves over a bony prominence. The bursae around the

glenohumeral joint are of special clinical importance because some of them communicate with the joint

cavity (e.g., the subscapular bursa). Consequently, opening a bursa may mean entering the cavity of the

glenohumeral joint.

Subscapular Bursa: is located between the tendon of the subscapularis and the neck of the scapula. The

bursa protects the tendon where it passes inferior to the root of the coracoid process and over the neck of

the scapula.

Subacromial Bursa (Subdeltoid bursa): is located between the acromion, coraco-acromial ligament,

superiorly and joint capsule of the glenohumeral joint inferiorly.

Figure 17. Glenohumeral (shoulder) joint Figure 18. Bursae around the shoulder jointhttp://aftabphysio.blogspot.com/2010/08/joints-of-upper-limb.html http://www.shoulderdoc.co.uk/patient_info/shoulder-anatomy.asp

Dislocations of the Shoulder JointAnterior–Inferior Dislocations


CLINICAL ANATOMY

http://www.shoulderdoc.co.uk/patient_info/shoulder-anatomy.asp

http://aftabphysio.blogspot.com/2010/08/joints-of-upper-limb.html


Sudden violence applied to the humerus with the joint fully abducted tilts the humeral head downward onto

the inferior weak part of the capsule, which tears, and the humeral head comes to lie inferior to the glenoid

fossa.

Posterior DislocationsPosterior dislocations are rare and are usually caused by direct violence to the front of the joint. On

inspection of the patient with shoulder dislocation, the rounded appearance of the shoulder is seen to be

lost because the greater tuberosity of the humerus is no longer bulging laterally beneath the deltoid muscle.

.

1. Articulation between Humerus, ulna and radius

2. Distinct feature of the joint Located 2-3 cm inferior to the epicondyles of the humerus

3. Synovial joint type Hinge type


5. Articular surfaces The spool-shaped trochlea and spheroidal capitulum of the humerus articulate with the

trochlear notch of the ulna and the slightly concave superior aspect of the head of the radius, respectively;

therefore, there are humeroulnar and humeroradial articulations.

6. Joint capsule of elbow joint The fibrous layer of the joint capsule surrounds the elbow joint. The joint

capsule is weak anteriorly and posteriorly but is strengthened on each side by collateral ligaments.

7. Ligaments of the elbow joint

Medial (ulnar) and lateral (radial) collateral ligamentsThe collateral ligaments of the elbow joint are strong triangular bands that are medial and lateral thickenings

of the fibrous layer of the joint capsule.

The lateral, fan-like radial collateral ligament extends from the lateral epicondyle of the humerus

and blends distally with the anular ligament of the radius, which encircles and holds the head of the radius in

the radial notch of the ulna. The anular ligament forms the proximal radio-ulnar joint and permits pronation

and supination of the forearm.

The medial, triangular ulnar collateral ligament extends from the medial epicondyle of the humerus

to the coronoid process and olecranon of the ulna and consists of three bands: (1) the anterior cord-like

band is the strongest, (2) the posterior fan-like band is the weakest, and (3) the slender oblique band

deepens the socket for the trochlea of the humerus.

8. Movements of the elbow joint

Flexion and extension


RADIOCARPAL JOINTELBOW JOINT


Flexion and extension occur at the elbow joint. The long axis of the fully extended ulna makes an angle of

approximately 170° with the long axis of the humerus. This angle is called the carrying angle, named for the

way the forearm angles away from the body when something is carried. The obliquity of the ulna and thus of

the carrying angle is more pronounced (the angle is approximately 10° more acute) in women than in men. It

is said to enable the swinging limbs to clear the wide female pelvis when walking. In the anatomical position,

the elbow is against the waist.

9. Bursae of the elbow joint Only some of the bursae around the elbow joint are clinically important.

The three olecranon bursae are the:

•Intratendinous olecranon bursa, which is sometimes present in the tendon of triceps brachii.

•Subtendinous olecranon bursa, which is located between the olecranon and the triceps tendon, just

proximal to its attachment to the olecranon.

•Subcutaneous olecranon bursa, which is located in the subcutaneous connective tissue over the olecranon.

Figure 19. Elbow jointhttp://www.aaos75th.org/stories/patient_story.htm?id=11

Figure 20. Bursae around the elbow jointhttp://www.joint-pain-expert.net/olecranon-bursitis.html


http://www.joint-pain-expert.net/olecranon-bursitis.html

http://www.aaos75th.org/stories/patient_story.htm?id=11


Stability of the Elbow JointThe elbow joint is stable because of the wrench-shaped articular surface of the olecranon and the

pulley-shaped trochlea of the humerus; it also has strong medial and lateral ligaments. When examining the

elbow joint, the physician must remember the normal relations of the bony points. In extension, the medial

and lateral epicondyles and the top of the olecranon are in a straight line; in flexion, the bony points form

the boundaries of an equilateral triangle.

Dislocations of the Elbow JointElbow dislocations are common, and most are posterior. Posterior dislocation usually follows falling

on the outstretched hand. Posterior dislocations of the joint are common in children because the parts of

the bones that stabilize the joint are incompletely developed. Avulsion of the epiphysis of the medial

epicondyle is also common in childhood because then the medial ligament is much stronger than the bond

of union between the epiphysis and the diaphysis.

1. Articulation between Radius and ulna proximally

2. Distinct feature of the joint -

3. Synovial joint type Pivot type


5. Articular surfaces The head of the radius articulates with the radial notch of the ulna.

6. Ligaments of the proximal radio-ulnar joint


PROXIMAL(SUPERIOR) RADIO-ULNAR JOINT

CLINICAL ANATOMY


Annular ligamentThe radial head is held in position by the anular ligament of the radius. The strong anular ligament is

attached to the ulna anterior and posterior to its radial notch. It surrounds the articulating bony surfaces and

forms a collar that, with the radial notch, creates a ring that completely encircles the head of the radius.

7. Movements of the proximal radio-ulnar joint

Supination & pronationThe proximal (superior) radio-ulnar joint is a pivot type of synovial joint that allows movement of the head of

the radius on the ulna.

During pronation and supination, it is the radius that rotates; its head rotates within the cup-shaped

collar formed by the anular ligament and the radial notch on the ulna. Distally, the end of the radius rotates

around the head of the ulna. Almost always, supination and pronation are accompanied by synergistic

movements of the glenohumeral and elbow joints that produce simultaneous movement of the ulna, except

when the elbow is flexed.

Figures 21 & 22. Proximal radio-ulnar jointhttp://teachmeanatomy.net/upper-limb-2/joints-of-the-upper-limb/radioulnar-joints http://www.msdlatinamerica.com/ebooks/HandSurgery/sid484870.html

1. Articulation between Radius and ulna distally


3. Synovial joint type Pivot type

4. Articular disc Yes. A fibrocartilaginous, triangular articular disc of the distal radioulnar joint (sometimes

referred to by clinicians as the “triangular ligament”) binds the ends of the ulna and radius together and is


DISTAL (INFERIOR) RADIO-ULNAR JOINT

http://www.msdlatinamerica.com/ebooks/HandSurgery/sid484870.html

http://teachmeanatomy.net/upper-limb-2/joints-of-the-upper-limb/radioulnar-joints


the main uniting structure of the joint. The articular disc separates the cavity of the distal radio-ulnar joint

from the cavity of the wrist joint.

5. Articular surfaces The rounded head of the ulna articulates with the ulnar notch on the medial side of the

distal end of the radius.

6. Ligaments of the distal radio-ulnar joint

Anterior and posterior ligamentsAnterior and posterior ligaments strengthen the fibrous layer of the joint capsule of the distal radio-ulnar

joint. These relatively weak transverse bands extend from the radius to the ulna across the anterior and

posterior surfaces of the joint.

7. Movements of the distal radio-ulnar joint

The radius moves around the relatively fixed distal end of the ulna. The distal radio-ulnar joint allows the

distal end of the radius to move anteromedially over the ulna. During pronation of the forearm and hand,

the distal end of the radius moves (rotates) anteriorly and medially, crossing over the ulna anteriorly. During

supination, the radius uncrosses from the ulna, its distal end moving (rotating) laterally and posteriorly so

the bones become parallel.

Figure 23. Distal radio-ulnar jointhttp://en.wikipedia.org/wiki/File:Gray334.png

Radioulnar Joint Disease


CLINICAL ANATOMY

http://en.wikipedia.org/wiki/File:Gray334.png


The proximal radioulnar joint communicates with the elbow joint, whereas the distal radioulnar joint

does not communicate with the wrist joint. In practical terms, this means that infection of the elbow joint

invariably involves the proximal radioulnar joint.

The strength of the proximal radioulnar joint depends on the integrity of the strong anular ligament.

Rupture of this ligament occurs in cases of anterior dislocation of the head of the radius on the capitulum of

the humerus. In young children, in whom the head of the radius is still small and undeveloped, a sudden jerk

on the arm can pull the radial head down through the anular ligament.

1. Articulation between Radius and carpal bones

2. Distinct feature of the joint

3. Synovial joint type Condyloid (ellipsoid) type

4. Articular disc Yes.

5. Articular surfaces The wrist (carpus), the proximal segment of the hand, is a complex of eight carpal

bones, articulating proximally with the forearm via the wrist joint and distally with the five metacarpals. The

ulna does not participate in the wrist joint. The distal end of the radius and the articular disc of the distal

radio-ulnar joint articulate with the proximal row of carpal bones, except for the pisiform.

6. Ligaments of the wrist joint

Dorsal and palmar radiocarpal ligamentsUlnar collateral ligamentRadial collateral ligament

The fibrous layer of the joint capsule is strengthened by strong dorsal and palmar radiocarpal

ligaments. The palmar radiocarpal ligaments pass from the radius to the two rows of carpals. They are strong

and directed so that the hand follows the radius during supination of the forearm. The dorsal radiocarpal

ligaments take the same direction so that the hand follows the radius during pronation of the forearm.

The joint capsule is also strengthened medially by the ulnar collateral ligament, which is attached to

the ulnar styloid process and triquetrum. The joint capsule is also strengthened laterally by the radial

collateral ligament, which is attached to the radial styloid process and scaphoid.

7. Movements of the wrist joint

FlexionExtension Abduction (Radial deviation)


WRIST JOINT (RADIOCARPAL JOINT)


Adduction (Ulnar deviation)Circumduction

The movements at the wrist joint may be augmented by additional smaller movements at the

intercarpal and midcarpal joints. The movements are flexion—extension, abduction—adduction (radial

deviation-ulnar deviation), and circumduction. The hand can be flexed on the forearm more than it can be

extended; these movements are accompanied (actually, are initiated) by similar movements at the

midcarpal joint between the proximal and the distal rows of carpal bones. Adduction of the hand is greater

than abduction. Most adduction occurs at the wrist joint. Abduction from the neutral position occurs at the

midcarpal joint. Circumduction of the hand consists of successive flexion, adduction, extension, and

abduction.

8. Surface anatomy of the wrist joint The position of the joint is indicated approximately by a line joining

the styloid processes of the radius and ulna, or by the proximal wrist crease.

Figure 24. Wrist (Radiocarpal) jointhttp://teachmeanatomy.net/upper-limb-2/joints-of-the-upper-limb/wrist-joint

Wrist Joint InjuriesA fall on the outstretched hand can strain the anterior ligament of the wrist joint, producing synovial

effusion, joint pain, and limitation of movement. These symptoms and signs must not be confused with

those produced by a fractured scaphoid or dislocation of the lunate bone, which are similar.

Falls on the Outstretched HandIn falls on the outstretched hand, forces are transmitted from the scaphoid to the distal end of the

radius, from the radius across the interosseous membrane to the ulna, and from the ulna to the humerus;

thence, through the glenoid fossa of the scapula to the coracoclavicular ligament and the clavicle, and

finally, to the sternum. If the forces are excessive, different parts of the upper limb give way under

the strain. The area affected seems to be related to age. In a young child, for example, there may be a

posterior displacement of the distal radial epiphysis; in the teenager the clavicle might fracture; in the young http://www.youtube.com/yeditepeanatomy 32

INTERCARPAL JOINTS

CLINICAL ANATOMY

http://teachmeanatomy.net/upper-limb-2/joints-of-the-upper-limb/wrist-joint/


adult the scaphoid is commonly fractured; and in the elderly the distal end of the radius is fractured about 1

in. (2..5 cm) proximal to the wrist joint (Colles’ fracture).

1. Articulation between carpal bones (the intercarpal joints interconnect the carpal bones)


3. Synovial joint type Plane type


5. Articular surfaces

Joints between the carpal bones of the proximal row.

Joints between the carpal bones of the distal row.

The midcarpal joint, a complex joint between the proximal and distal rows of carpal bones.

The pisotriquetral joint, formed from the articulation of the pisiform with the palmar surface of the

triquetrum.

6. Ligaments of the intercarpal joints

Anterior, posterior, and interosseous ligaments7. Movements of the intercarpal joints

GlidingFlexion & extension of the handAbduction & adduction of the handThe gliding movements possible between the carpals occur concomitantly with movements at the wrist

joint, augmenting them and increasing the overall range of movement. Flexion and extension of the hand

are actually initiated at the midcarpal joint, between the proximal and the distal rows of carpals. Most

flexion and adduction occur mainly at the wrist joint, whereas extension and abduction occur primarily at

the midcarpal joint. Movements at the other intercarpal joints are small, with the proximal row being more

mobile than the distal row.

1. Articulation between carpal bones & metacarpals, between metacarpals



CARPOMETACARPAL & INTERMETACARPAL JOINTS


3. Synovial joint type Plane type plane except for the carpometacarpal joint of the thumb, which is a saddle

joint.


5. Articular surfaces The distal surfaces of the carpals of the distal row articulate with the carpal surfaces of

the bases of the metacarpals at the carpometacarpal joints. The important carpometacarpal joint of the

thumb is between the trapezium and the base of the 1st metacarpal; it has a separate articular cavity. Like

the carpals, adjacent metacarpals articulate with each other; intermetacarpal joints occur between the

radial and ulnar aspects of the bases of the metacarpals.

6. Ligaments of the carpometacarpal and intermetacarpal joints

Palmar and dorsal carpometacarpal and palmar and dorsal intermetacarpal ligamentsInterosseus metacarpal ligamentsSuperficial and deep transverse metacarpal ligamentsThe bones are united in the region of the joints by palmar and dorsal carpometacarpal and palmar and

dorsal intermetacarpal ligaments and by interosseous intermetacarpal ligaments. In addition, the

superficial and deep transverse metacarpal ligaments (the former part of the palmar aponeurosis),

associated with the distal ends of the metacarpals, play a role in limiting movement at these two joints as

they limit separation of the metacarpal heads.

7. Movements of the carpometacarpal and intermetacarpal joints

The carpometacarpal joint of the thumb permits angular movements in any plane (flexion-extension,

abduction-adduction, or circumduction) and a restricted amount of axial rotation. Most important, the

movement essential to opposition of the thumb occurs here.

Almost no movement occurs at the carpometacarpal joints of the 2nd and 3rd digits, that of the 4th

digit is slightly mobile, and that of the 5th digit is moderately mobile, flexing and rotating slightly during a

tight grasp. When the palm of the hand is “cupped” (as during pad-to-pad opposition of thumb and little

finger), two thirds of the movement occur at the carpometacarpal joint of the thumb, and one third occurs

at the carpometacarpal and intercarpal joints of the 4th and 5th fingers.

1. Articulation between metacarpals and phalanges and between phalanges



METACARPOPHALANGEAL & INTERPHALANGEAL JOINTS


3. Synovial joint type The metacarpophalangeal joints are the condyloid type of synovial joint that permit

movement in two planes: flexion-extension and adduction-abduction. The interphalangeal joints are the

hinge type of synovial joint that permit flexion-extension only.


5. Articular surfaces The heads of the metacarpals articulate with the bases of the proximal phalanges in the

metacarpophalangeal (MP) joints, and the heads of the phalanges articulate with the bases of more distally

located phalanges in the interphalangeal (IP) joints.

6. Ligaments of the carpometacarpal and intermetacarpal joints

Medial and lateral collateral ligamentsPalmar ligamentsThe fibrous layer of each MC and IP joint capsule is strengthened by two (medial and lateral) collateral

ligaments. These ligaments have two parts:

• Denser cord-like parts pass distally from the heads of the metacarpals and phalanges to the bases of the

phalanges.

• Thinner fan-like parts pass anteriorly to attach to thick, densely fibrous or fibrocartilaginous plates, the

palmar ligaments (plates), which form the palmar aspect of the joint capsule.

The fan-like parts of the collateral ligaments cause the palmar ligaments to move like a visor over the

underlying metacarpal or phalangeal heads.

The palmar ligaments of the 2nd-5th MP joints are united by deep transverse metacarpal ligaments that

hold the heads of the metacarpals together.

7. Movements of the carpometacarpal and intermetacarpal joints

Flexion-extension, abduction-adduction, and circumduction of the 2nd-5th digits occur at the 2nd-5th MP

joints. Movement at the MP joint of the thumb is limited to flexion-extension. Only flexion and extension

occur at the IP joints.


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