ANATOMYII.COMMITEE

BONES & JOINTS OF THE UPPER LIMB

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UPPER LIMB:ability to place the hand in the proper position in space by movements at the scapulothoracic, glenohumeral, elbow, radio-ulnar, and wrist joints

LOWER LIMB: support, stability, and locomotion

Pectoral girdle& bones of the free part of the upper limb superior appendicular skeletonPelvic girdle & bones of the free part of the lower limb inferior appendicular skeleton

The clavicles and scapulae of the pectoral girdle are supported, stabilized, and moved by axio-appendicular muscles that attach to the relatively fixed ribs, sternum, and vertebrae of the axial skeleton.

only bony attachment between trunk & upper limb palpable along its entire length has a gentle S-shaped contour forward-facing convex part medial forward-facing concave part lateral

CLAVICLE- LITTLE KEY

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. (Click on the key in the previous slide and read the first sentence)

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.

posterolateral aspect of the thorax, on the 2nd-7th ribs three angles (lateral, superior, and inferior) three borders (superior, lateral, and medial) two surfaces (costal and posterior) three processes (acromion, spine, and coracoid process)

SCAPULA

largest bone in the upper limb articulates with the scapula at the glenohumeral joint articulates with 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

HUMERUS- ARM BONE

FossaeCoronoid fossa adjacent to the radial fossa superior to the trochlea. receives the coronoid process of the ulna during full flexion of the elbow.Olecranon fossa largest fossa immediately superior to trochlea on the posterior surface of the distal end of humerus 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 accommodates the edge of the head of the radius when the forearm is fully flexed.

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.

Lateral to MedialProximal-Distal

S L T PT T C H

Carpal arch The carpal bones do not lie in a flat plane; rather, they form an arch, whose base is directed anteriorly. Lateral side of this base is formed by tubercles of the scaphoid and trapezium. Medial side is formed by the pisiform and the hook of hamate.

JOINT TYPE MOVEMENTSternoclavicular Saddle, fxn: ball-and-socket Raising (60°) & rotating the

clavicleAnterior and posterior movements of the clavicle

Acromioclavicular Plane Anteroposterior and vertical planes

together with some axial rotation

Shoulder Ball and socket Circumduction

Elbow Hinge Flexion and extension

Prox. radioulnar Pivot Pronation & supination

Distal radioulnar Pivot Pronation & supination

JOINT TYPE MOVEMENTWrist Condyloid (ellipsoid) type Circumduction

Intercarpal Plane GlidingFlexion & extension of the hand

Abduction & adduction of the hand

Carpometacarpal Plane Circumduction, some axial rotation, Thumb- Saddle Opposition [thumb]

Intermetacarpal Plane

Metacarpophalangeal Condyloid Flexion-extension-abduction-adduction

Interphalangeal Hinge Flexion-extension

LIGAMENTSAnterior and posterior sternoclavicular ligamentsCostoclavicular ligamentInterclavicular ligamentAcromioclavicular ligamentCoracoclavicular ligament-conoid ligament & trapezoid ligamentGlenohumeral ligamentsCoracohumeral ligamentTransverse humeral ligamentCoracoacromial ligamentMedial (ulnar) and lateral (radial) collateral ligaments Annular ligamentAnterior and posterior ligaments of the distal radio-ulnar jointDorsal and palmar radiocarpal ligamentsUlnar collateral ligamentRadial collateral ligamentAnterior, posterior, and interosseous ligamentsPalmar and dorsal carpometacarpal and palmar and dorsal intermetacarpal ligamentsInterosseus metacarpal ligamentsSuperficial and deep transverse metacarpal ligamentsMedial and lateral collateral ligamentsPalmar ligaments

Sternoclavicular joint

Acromioclavicular joint

Shoulder joint

Elbow joint

Wrist joint

Carpometacarpal & Intermetacarpal joints

Intercarpal joints

Metacarpophalangeal & interphalangeal joints

SOME FUNCTIONAL ANATOMY OF THE LIGAMENTSAnterior & posterior sternoclavicular ligaments reinforce the joint capsule anteriorly & posteriorly.

Interclavicular ligament strengthens the capsule superiorly.

Costoclavicular ligament limits elevation of the pectoral girdle.

Acromioclavicular ligament strengthens the acromioclavicular joint superiorly. However, the integrity of the joint is maintained by extrinsic ligaments, distant from the joint itself.

Sternoclavicular joint

Acromioclaviular joint

coracoclavicular ligament

Shoulder joint

Glenohumeral ligaments strengthen the anterior aspect of the joint capsule.

Coracohumeral ligament strengthens the capsule superiorly.

Transverse humeral ligament holds the synovial sheath and tendon of the biceps brachii in place during movements of the glenohumeral joint.

SOME FUNCTIONAL ANATOMY OF THE LIGAMENTS

Elbow joint

Proximal radio-ulnar joint

Wrist joint

Lateral collateral ligament complex doesn't contribute as much to elbow stability as does the medial collateral ligament complex.

Anular ligament of the radius, which encircles and holds the head of the radius in the radial notch of the ulna.

permits pronation and supination of the forearm.

Palmar radiocarpal ligaments strong and directed so that the hand follows the radius during supination of the forearm. 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. TThe joint capsule is also strengthened laterally by the radial collateral ligament. S