The Wrist & Hand Joints • Many sports require precise functioning of wrist & hand • Archery, bowling, golf, baseball, tennis, etc. Chapter 7 require combined use of wrist & hand joints • Relate functional anatomy to joint actions The Wrist and Hand Joints – flexion, extension, abduction, & adduction of wrist & hand Manual of Structural Kinesiology – 29 bones – More than 25 joints R.T. Floyd, EdD, ATC, CSCS – More than 30 muscles • 18 are intrinsic © 2007 McGraw-Hill Higher Education. All rights reserved. 7-1 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-2 Bones Bones • 29 bones, including radius & ulna Eight carpal bones – 8 carpal bones in 2 rows of 4 bones form wrist • Proximal row from radial – 5 metacarpal bones, numbered 1 to 5 from to ulnar side thumb to little finger, join the wrist bones – scaphoid (boat-shaped) or – 14 phalanges (digits), 3 for each phalange navicular except the thumb, which has only 2 – lunate (moon-shaped) • Proximal, middle, & distal – triquetrum (three-cornered) – Thumb has a sesamoid bone in its flexor – pisiform (pea-shaped) tendon – Other sesamoids may occur in joints of fingers From Anthony CP, Kolthoff NJ: Textbook of anatomy and physiology , ed 9, St Louis, 1975, Mosby. © 2007 McGraw-Hill Higher Education. All rights reserved. 7-3 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-4 Bones Bones Eight carpal bones • Scaphoid most often injured • Distal row, from the radial – From falling on outstretched hand to ulnar side – Often dismissed as a sprain – trapezium (greater – Significant problem if not recognized & multangular) treated properly – trapezoid (lesser multangular) – Usually long period of precise – capitate (head-shaped) immobilization or surgery – hamate (hooked) © 2007 McGraw-Hill Higher Education. All rights reserved. 7-5 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-6 1 Bones Bones • Carpal bones form a three-sided arch • Medial epicondyle, – concave on palmar side medial condyloid ridge, – bony arch is spanned by transverse carpal & volar & coranoid process - carpal ligaments origin for many wrist & – creates the carpal finger flexors tunnel • Lateral epicondyle & – frequently a source of lateral supracondylar problems known ridge - origin for many as carpal tunnel wrist & finger extensors syndrome © 2007 McGraw-Hill Higher Education. All rights reserved. 7-7 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-8 Bones Joints • Key distal bony landmarks for • Wrist joint muscles involved in wrist – condyloid-type joint motion – allows flexion, – base of 2 nd , 3 rd , & 5 th metacarpals, pisiform, & extension, abduction, & hamate adduction • Key bony landmarks for – motion occurs primarily finger muscles between distal radius & – base of proximal, middle, & proximal carpal row distal phalanxes (scaphoid, lunate, & – base of 1 st metacarpal, proximal triquetrum) & distal phalanxes of thumb © 2007 McGraw-Hill Higher Education. All rights reserved. 7-9 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-10 Joints Joints • Wrist joint • Each finger has 3 joints – 70 to 90 degrees of flexion – Metacarpophalangeal (MCP) joints – 65 to 85 degrees of extension – Proximal interphalangeal (PIP) joints – 15 to 25 degrees of abduction – Distal interphalangeal (DIP) joints – 25 to 40 degrees of adduction © 2007 McGraw-Hill Higher Education. All rights reserved. 7-11 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-12 2 Joints Joints • Each finger has 3 joints • Each finger has 3 joints – Metacarpophalangeal (MCP) joints – Proximal interphalangeal (PIP) joints • Condyloid • Ginglymus • 0 to 40 degrees of extension • Full extension to 90 to 120 degrees of • 85 to 100 degrees of flexion flexion © 2007 McGraw-Hill Higher Education. All rights reserved. 7-13 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-14 Joints Joints • Each finger has 3 joints • Thumb has 2 joints – Distal interphalangeal (DIP) joints – Metacarpophalangeal (MCP) joint • Ginglymus • Full extension into 40 to 90 degrees of • Flex 80 to 90 degrees from full extension flexion • Ginglymus © 2007 McGraw-Hill Higher Education. All rights reserved. 7-15 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-16 Joints Joints • Thumb has 2 joints • Thumb has 2 joints – Interphalangeal (IP) joint – Carpometacarpal (CMC) joint of thumb • Flex 80 to 90 degrees • Unique saddle-type joint • Ginglymus • 50 to 70 degrees of abduction • Flex 15 to 45 degrees & extend 0 to 20 degrees © 2007 McGraw-Hill Higher Education. All rights reserved. 7-17 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-18 3 Movements Movements • Wrist • Middle phalange is reference point to – Flexion & extension differentiate abduction & adduction – Thumb, index & middle fingers abduct when – Abduction & adduction they move laterally toward radial side of hand • Fingers – Ring & little fingers adduction when they move – Flex & extend medially toward ulnar side of hand – Medial movement of thumb, index & middle – MCP joints also abduct & adduct fingers toward ulnar side of hand is adduction – Lateral movement of ring & little finger toward radial side of hand is abduction © 2007 McGraw-Hill Higher Education. All rights reserved. 7-19 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-20 Movements Movements • Flexion • Extension – movement of palm of – movement of back of hand hand and/or phalanges and/or phalanges toward toward anterior or volar posterior or dorsal aspect aspect of forearm of forearm © 2007 McGraw-Hill Higher Education. All rights reserved. 7-21 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-22 Movements Movements • Abduction (radial • Adduction (ulnar flexion) flexion) – movement of little finger – movement of thumb side of hand toward side of hand toward medial aspect or ulnar lateral aspect or side of forearm radial side of forearm – Also, movement of – Also, movement of fingers toward middle fingers away from finger middle finger © 2007 McGraw-Hill Higher Education. All rights reserved. 7-23 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-24 4 Movements Muscles • Opposition Extrinsic muscles of wrist & hand grouped according to function & location – movement of thumb across palmar aspect to • 6 muscles move wrist but not fingers & thumb oppose any or all of the – 3 wrist flexors phalanges • flexor carpi radialis • Reposition • flexor carpi ulnaris • palmaris longus – movement of thumb as it returns to anatomical – 3 wrist extensors position from opposition • extensor carpi radialis longus with hand and/or fingers • extensor carpi radialis brevis • extensor carpi ulnaris © 2007 McGraw-Hill Higher Education. All rights reserved. 7-25 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-26 Muscles Muscles • 9 muscles primary movers of phalanges – Extensors – Also involved in wrist joint actions • Extensor digitorum – Generally weaker in their wrist actions • Extensor indicis – Flexors • Extensor digiti minimi • Extensor pollicis longus (thumb • Flexor digitorum superficialis extensor) • Flexor digitorum profundus • Extensor pollicis brevis (thumb extensor) • Flexor pollicis longus (thumb flexor) – Abductor of thumb & wrist – Abductor pollicis longus © 2007 McGraw-Hill Higher Education. All rights reserved. 7-27 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-28 Muscles Muscles • All wrist flexors generally have their origins on • Carpal tunnel syndrome anteromedial aspect of proximal forearm and – Swelling & inflammation can cause increased medial epicondyle of humerus with insertions pressure in carpal tunnel resulting in decreased function of median nerve leading to reduced motor on anterior aspect of wrist & hand & sensation function in its distribution • Median nerve & all flexor tendons except – particularly common with repetitive use of the flexor carpi ulnaris & palmaris longus pass hand and wrist in manual labor and clerical work through carpal tunnel such as typing and keyboarding – Often, 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 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-29 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-30 5 Muscles Muscles • Wrist extensors generally have their origins • Wrist abductors on posterolateral aspect of proximal forearm – Generally cross wrist joint anterolaterally & & lateral humeral epicondyle with insertions posterolaterally to insert on radial side of located on posterior aspect of wrist & hand hand • Flexor & extensor tendons immediately • Flexor carpi radialis proximal to wrist are held in place on palmar • Extensor carpi radialis longus & dorsal aspects by transverse bands of • Extensor carpi radialis brevis tissue known as flexor & extensor retinaculum • Abductor pollicis longus to prevent the tendons from bowstringing • Extensor pollicis longus during flexion & extension • Extensor pollicis brevis © 2007 McGraw-Hill Higher Education. All rights reserved. 7-31 © 2007 McGraw-Hill Higher Education. All rights reserved. 7-32 Muscles Muscles • Wrist adductors • Intrinsic hand muscles have origins & insertions on bones of hand – cross wrist joint anteromedially & – Radial side - four muscles of thumb posteromedially to insert on ulnar side of • opponens pollicis hand • abductor pollicis brevis • Flexor carpi ulnaris • flexor pollicis brevis • Extensor carpi ulnaris • adductor pollicis – Ulnar side