Tana Pearson Galina Nesenchuk Vira Iatchenko Hand and Wrist Joint Tana Pearson Galina Nesenchuk Vira Iatchenko

BONES: Ulna, Radius The ulna is a long bone, prismatic in form, placed at the medial side of the forearm, parallel with the radius. Radius

Bones: Ulna Head of ulna – small, rounded surface at distal end of bone Styloid process of ulna – small, medial projection from head region; forms medial portion of wrist joint

Bones: Radius Styloid process of radius pointed lateral projection at distal end of bone; forms lateral portion of wrist joint Ulnar notch of radius slight depression at mediodistal end; area of articulation with ulna

Bones and Joints There are 15 bones that form connections from the end of the forearm to the hand. The wrist itself contains eight small bones, called carpal bones. These bones are grouped in two rows across the wrist. The proximal row is where the wrist creases when you bend it. Beginning with the thumb-side of the wrist, the proximal row of carpal bones is made up of the scaphoid, lunate, and triquetrum. The second row of carpal bones, called the distal row, meets the proximal row a little further toward the fingers. The distal row is made up of the trapezium, trapezoid, capitate, hamate, and pisiform bones. The proximal row of carpal bones connects the two bones of the forearm, the radius and the ulna, to the bones of the hand. The bones of the hand are called the metacarpal bones. These are the long bones that lie within the palm of the hand. The metacarpals attach to the phalanges, which are the bones in the fingers and thumb.

WRIST Carpals 1. Scaphoid 2. Lunate 3. Triquetrum 4. Pisiform 5. Trapezium 6. Trapezoid 7. Capitate 8. Hamate

WRIST Metacarpal bones: Phalangeal bones: (thumb side is #1) Nambered 1-5 (thumb side is #1) Phalangeal bones: Fingers numbered 1-5 (thumb is #1) Proximal Middle (intermediate) Distal

Joints Distal interphalangeal joint (DIP) Proximal interphalangeal joint (PIP) Metacarpo-phalangeal joint (MP)

Joint and capsule Synovial Joint: Joints where the articulating bones are separated by a fluid-containing joint cavity. Allows freedom of movement. Articular Capsule: Fibrous Capsule Synovial Membrane Joint Cavity Articular cartilage

ORIGIN: Attachment of a muscle tendon to the stationary bone. INSERTION: Attachment of the other muscle tendon to the movable bone. ACTION: The movement that occurs at the joint due to muscle contraction.

EXTENSOR MUSCLES

ORGIN, INSERTION & ACTION OF EXTENSOR MUSCLES Extensor carpi radialis longus: Extensor carpi radialis brevis: O: supracondylar ridge of humerus I: base of 2nd metacarpal A: wrist extension, radial deviation O: lateral epicondyle of humerus I: base of 3rd metacarpal A: wrist extension Extensor digitorum: Extensor carpi ulnaris: O: lateral epicondyle of the humerus I: base of distal phalanx of the 2nd-5th fingers A: extends all 3 joints of the fingers O: lateral epicondyle of humerus I: medial side of base of 5th metacarpal A: extends & adducts wrist

EXTENSOR MUSCLES CONT. Extensor digiti minimi: O: lateral epicondyle of humerus I: base of distal phalanx of 5th finger A: extends all joints of 5th finger Extensor pollicis brevis: O: posterior distal radius I: base of the proximal phalanx of pollex A: extends MP joint of thumb Extensor pollicis longus: O: middle posterior ulna & interosseous membrane I: base of distal phalanx of pollex A: extends MP & IP joints of the thumb

FLEXOR MUSCLES

ORGIN, INSERTION & ACTION OF FLEXOR MUSCLES Flexor carpi radialis: O: medial epicondyle of the humerus I: base of 2nd & 3rd metacarpals A: wrist flexion, radial deviation Flexor carpi ulnaris: O: medial epicondyle of humerus I: pisiform & base of 5th metacarpal A: wrist flexion , ulnar deviation Flexor digitorum superficialis: O: common flexor tendon, coronoid process & radius I: sides of the middle phalanx of the 4 fingers A: flexes MP & PIP joints of the fingers

FLEXOR MUSCLES CONT. Flexor digitorum profundus: O: upper ¾ of ulna I: distal phalanx of the 4 fingers (2-5) A: flexes all 3 joints of the fingers Flexor pollicis longus: O: radius, anterior surface I: distal phalanx of pollex A: flexes all joints of the pollex or thumb Abductor pollicis longus: O: post. radius , interosseous membrane, middle ulna I: base of the 1st metacarpal A: abducts pollex Palmaris longus: O: medial epicondyle of humerus I: palmar fascia A: assistive in wrist flexion

Ligaments Tendons and Sheaths Articular Ligaments Fibrous dense regular connective tissue. Connect bones to other bones. They act as mechanical reinforcements. Within synovial joints, act as a stabilizer to prevent excessive or undesirable motion. Tendons and aponeurosis Tendon – ropelike connection anchoring muscle to the connective tissue covering of a skeletal element (bone or cartilage) Aponeurosis – sheetlike tendon Durable, withstand abrasion of rough bony projections, and relatively small size conserve space. Sheaths An elongated/flattened sac, lined with synovial fluid, that wraps completely around a tendon subjected to friction. They are common where several tendons are crowded together within narrow canals, ie wrist.

Ligaments and sheaths Palmar Aponeurosis Flexor retinaculum – anterior The extrinsic hand muscles are located in the forearm. When contracted, most of the tendons of these muscles are prevented from standing up like taut bowstrings around the wrist by passing under the flexor retinaculum on the palmar side and the extensor retinaculum on the dorsal side. ERLies distal to the radial joint, spans across the carpal bones, forming a bridge over the extensor tendons. Binds down the extensor tendons of the fingers and thumb. Palmar Aponeurosis Flexor retinaculum – anterior Extensor retinaculum – posterior Commom flexor sheath

Tendons Anterior: Posterior: Palmaris longus Flexor carpi longus Flexor retinaculum Palmar aponeurosis Posterior: Extensor carpi ulnaris Extensor digitorum Extensor pollicis brevis Extensor longus Extensor retinaculum Flexor carpi ulnaris Posterior View Anterior View

Arteries Two arteries enter the hand: Ulnar Artery Radial Artery Together, the branches of these arteries form two arterial arches: Superficial palmar arch Deep palmar arch Branching distally off superficial palmar arch: Common palmar digitals There are two arteries entering the hand and these are the: 1. radial 2. ulnar. Together, the branches of these arteries form two arterial arches: 1. superificial 2. deep. The superficial arterial arch is formed mainly from the ulnar artery and is completed by the superficial branch of the radial. This completion is not always present or may be extremely small. The deep arterial arch is formed mainly by the deep branch of the radial artery and is finished by the deep branch of the ulnar artery. These arteries and the branches of the arches are shown in the adjacent diagrams. Palmar View

Veins Dorsal view The veins of the upper extremity are divided into two sets, superficial and deep; the two sets anastomose frequently with each other. Cephalic Vein Basilic Vein Superficial dorsal venous arch Deep dorsal venous arch Dorsal View

Nerves Ulnar Nerve Radial Nerve Median Nerve The radial nerve divides into a deep branch, which becomes the posterior interosseous nerve, and a superficial branch, which goes on to innervate the dorsum (back) of the hand. palmar cutaneous branch of median nerve arises from radial border of median nerve approximately 5 to 6 cm proximal to distal             transverse flexion crease of the wrist;     - it runs along the median nerve for 2 to 3 cm, and then runs along the ulnar border of the flexor carpi radialis tendon;            - in some cases it may run along the ulnar side of the palmaris longus tendon;     - when the tendon enters the flexor retinaculum comparment, the nerve passes between the two layers of the forearm fascia into the             root of the palmar aponeurosis;     - after 5-10 mm, the nerve divides into three terminal branches which cross the midpalmar aponeurosis to supply deep layers of dermis; Supplies the skin on the medial side of the hand: Runs medial side of Ulnar Artery Superficial and deep branches on the palmar side Palmar Cutaneous Branch Cutaneous branch on the dorsal side Dorsal Cutaneous Branch Palmar View

Cutaneous Innervation The radial nerve divides into a deep branch, which becomes the posterior interosseous nerve, and a superficial branch, which goes on to innervate the dorsum (back) of the hand. palmar cutaneous branch of median nerve arises from radial border of median nerve approximately 5 to 6 cm proximal to distal             transverse flexion crease of the wrist;     - it runs along the median nerve for 2 to 3 cm, and then runs along the ulnar border of the flexor carpi radialis tendon;            - in some cases it may run along the ulnar side of the palmaris longus tendon;     - when the tendon enters the flexor retinaculum comparment, the nerve passes between the two layers of the forearm fascia into the             root of the palmar aponeurosis;     - after 5-10 mm, the nerve divides into three terminal branches which cross the midpalmar aponeurosis to supply deep layers of dermis; Palmar cutaneous branch Ulnar, Radial, Median Dorsal cutaneous branch Ulnar, Radial

Veins Arteries and Nerve Summary Bring it all together

Innervations Muscle Nerve Artery Flexor carpi ulnaris Ulnar nerve Ulnar artery Flexor digitorum profundus Median and ulnar nerves Ulnar Artery Flexor digitorum superficialis Median nerve Palmaris longus Flexor carpi radialis Radial and Ulnar arteries Flexor pollicis longus Radial artery

Innervations Muscle Nerve Artery Abductor pollicis longus Radial nerve Posterior interosseous artery Extensor pollicis brevis Extensor pollicis longus Extensor carpi radialis longus Radial artery Extensor carpi radialis brevis Extensor carpi ulnaris Deep radial nerve Ulnar artery Extensor digitorum Recurrent interosseous artery Extensor digiti minimi

Surface Anatomy Compartments and Spaces

Surface Anatomy

Surface Anatomy

Surface Anatomy

Carpal Tunnel Syndrome Condition caused by compression or stretching of the medial nerve. Common disorder with people whose occupation require a great deal of wrist flexion or prolonged extension Carpal tunnel syndrome is a condition that causes a "needles-and- pins" sensation to the index and middle finger of the wrist, and is caused by compression or stretching of the medial nerve. It is a common disorder with people whose occupation require a great deal of wrist flexion or prolonged extension. It has been commonly called the "secretary's disease" and is seen commonly in writers, typists, pianists, and even more recently, computer professions. The symptoms can vary, but usually include pain in the middle area of the wrist, swelling of wrist, numbness or tingling in index and middle fingers, and loss of function of hand in severe cases. Splints applied to dorsiflex the wrist occasionally help. Cortisone injections may help, and surgery to strip away build-up of adhesive tissue may be required. This condition can recur even after treatment and tends to worsen in the evening and night. Writers Typists Pianists Computer professions

Carpal tunnel syndrome Symptoms Needles and pins sensation to the index and middle finger of the wrist. Pain in the middle area of the wrist, swelling of wrist, Numbness or tingling in index and middle fingers, Loss of function of hand in severe cases.

Carpal tunnel syndrome Cures Splints applied to dorsiflex the wrist occasionally help keep the wrist in a resting position. In this position, the carpal tunnel is as big as it can be, so the nerve has as much room as possible inside the carpal tunnel. Cortisone injections may help Surgery to strip away build-up adhesive tissue may be required. This condition can recur even after treatment and tends to worsen in the evening and night. A brace keeps the wrist in a resting position, not bent back or bent down too far. When the wrist is in this position, the carpal tunnel is as big as it can be, so the nerve has as much room as possible inside the carpal tunnel. A brace can be especially helpful for easing the numbness and pain felt at night because it can keep your hand from curling under as you sleep. The wrist brace can also be worn during the day to calm symptoms and rest the tissues in the carpal tunnel.