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 activities can be preventative Flexibility exercises for the wrist & finger flexors may be helpful
