The Wrist and Hand Joints

Abductor Pollicis Longus Muscle Action

Abduction of thumb at carpometacarpal joint, Abduction of wrist, Extension of thumb at carpometacarpal joint, Weak supination of forearm from a pronated position , Weak flexion of wrist

Extensor Digitorum Muscle Action

Extension of 2nd, 3rd, 4th, & 5th phalanges at metacarpophalangeal joints, Extension of wrist, Weak extension of elbow

Extensor Indicis Muscle Action

Extension of index finger at metacarpophalangeal joint, Weak wrist extension, Weak supination of forearm from a pronated position

Extensor Digiti Minimi Muscle Action

Extension of little finger at metacarpophalangeal joint, Weak wrist extension, Weak elbow extension

Extensor Pollicis Brevis Muscle Action

Extension of thumb at carpometacarpal & metacarpophalangeal joints, Weak wrist extension, Wrist abduction

Extensor Pollicis Longus Muscle Action

Extension of thumb at carpometacarpal, metacarpophalangeal, & interphalangeal joint, Extension of wrist, Abduction of wrist, Weak supination of forearm from a pronated position

Extensor Carpi Radialis Longus Muscle Action

Extension of wrist, Abduction of wrist , Weak flexion of elbow, Weak pronation to neutral from a fully supinated position

Extensor Carpi Radialis Brevis Muscle Action

Extension of wrist, Abduction of wrist, Weak flexion of elbow

Extensor Carpi Ulnaris Muscle Action

Extension of wrist, Adduction of wrist together with flexor carpi ulnaris muscle, Weak extension of elbow

What are the agonist muscles of the wrist extension?

Extensor carpi radialis longus Extensor carpi radialis brevis Extensor carpi ulnaris Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus Extensor pollicis brevis

What are the agonist muscles of the phalangeal extension?

Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus Extensor pollicis brevis

finger movements

Flex & extend MCP joints also abduct & adduct

wrist movements

Flexion & extension Abduction & adduction

Flexor Digitorum Profundus Muscle Action

Flexion of 4 fingers at metacarpophalangeal, proximal interphalangeal, & distal interphalangeal joints, Flexion of wrist

Flexor Digitorum Superficialis Muscle Action

Flexion of fingers at metacarpophalangeal & proximal interphalangeal joints, Flexion of wrist, Weak flexion of elbow

Flexor Pollicis Longus Muscle Action

Flexion of thumb carpometacarpal, metacarpophalangeal, & interphalangeal joints, Flexion of wrist, Abduction of wrist

Flexor Carpi Radialis Muscle Action

Flexion of wrist, Abduction of wrist, Weak flexion of elbow. Weak pronation of forearm

Flexor Carpi Ulnaris Muscle Action

Flexion of wrist, Adduction of wrist, together with extensor carpi ulnaris musclem, Weak flexion of elbow

Palmaris Longus Muscle Action

Flexion of wrist, Weak flexion of elbow

What are the agonist muscles of the wrist abduction?

Flexor carpi radialis Extensor carpi radialis longus Extensor carpi radialis brevis Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis

What are the agonist muscles of the wrist flexion?

Flexor carpi radialis Flexor carpi ulnaris Palmaris longus Flexor digitorum superficialis Flexor digitorum profundus Flexor pollicis longus

What are the agonist muscles of the wrist adduction?

Flexor carpi ulnaris Extensor carpi ulnaris

What are the agonist muscles of the phalangeal flexion?

Flexor digitorum superficialis Flexor digitorum profundus Flexor pollicis longus

what happens and how dose the scaphoid get injured?

From falling on outstretched hand Often dismissed as a sprain Significant problem if not recognized & treated properly Usually long period of immobilization or surgery

Each finger has 3 joint (except for the thumb)

Metacarpophalangeal (MCP) joints Proximal interphalangeal (PIP) joints Distal interphalangeal (DIP) joints

Extension(dorsiflexion)

Movement of the back of the hand/ and or the phalanges toward the posterior or dorsal aspect of the forearm; sometimes refereed to as hyperextension

Adduction(ulnar deviation, ulnar flexion)

Movement of the little finger side of the hand toward the medial aspect or ulnar side of the forearm; also movement of the fingers back together toward the middle finger

Flexion(palmar flexion)

Movement of the palm of the hand/and or the phalanges toward the anterior or volar aspect of the forearm

Opposition

Movement of the thumb across the palmar aspect to oppose any or all of the phalanges

Reposition

Movement of the thumb as it returns to anatomical position from opposition with the hand/ and or fingers

Abduction(radial deviation, radial flexion)

Movement of the thumb side of the hand toward the lateral aspect or radial side of the forearm; also movement of the fingers away from the middle finger

what happens during carpal tunnel?

Swelling & inflammation can cause increased pressure in carpal tunnel resulting in decreased function of median nerve leading to reduced motor & sensation function in its distribution

Wrist joint

condyloid-type joint allows flexion, extension, abduction, & adduction motion occurs primarily between distal radius & proximal carpal row (scaphoid, lunate, & triquetrum) known as radiocarpal jt.

3 wrist extensors but not fingers & thumb

extensor carpi radialis longus extensor carpi radialis brevis extensor carpi ulnaris

3 wrist flexors but not fingers & thumb

flexor carpi radialis flexor carpi ulnaris palmaris longus

How can carpal tunnel happen?

repetitive use of the hand and wrist in manual labor and clerical work such as typing and keyboarding

What is the most often injured bone in the hand?

scaphoid

what are the eight carpal bones?

scaphoid (boat-shaped) or navicular lunate (moon-shaped) triquetrum (three-cornered) pisiform (pea-shaped) trapezium (greater multangular) trapezoid (lesser multangular) capitate (head-shaped) hamate (hooked)

what can help carpal tunnel?

slight modifications in work habits and hand & wrist positions during these activitiescan be preventative Flexibility exercises for the wrist& finger flexors may be helpful