023 movements and muscles of the hand Flashcards
how are the digits of the hand labelled?
- thumb = digit 1
- index = digit 2
- middle = digit 3
- ring = digit 4
- pinky = digit 5
what is the hypothenar eminence?
- triangular mound on palm of hand under 5th digit - due to muscles
what is the thenar eminence?
- mound on palm under the thumb - due to muscles
what are the superficial and deep transverse metacarpal ligaments?
- connect the metacarpal phalangeal joints of digits 2-5 (not thumb)
- this means that the palm works as one unit
- link palmar ligaments
what are the annular and cruciate ligaments of the hand?
- part of the hand flexor pulley system
- cruciate = cross shaped between bands of annular ligaments
- act as bands over the flexor tendons
( also 1 oblique pulley on the thumb)
what are the extensor hoods of the hand?
-a continuous aponeurosis and tendons/intrinsic hand muscles that covers the dorsal surface of the finger phalanges from the metacarpophalangeal (MCP) joint to the distal phalanx
- helps with extension of fingers
what is a?
- extensor digitorum tendon
what is b?
- dorsal interosseous muscle
what is c?
- extensor hood
what is d?
- deep transverse metacarpal ligament
what is e?
- palmar ligament
what is f?
- lumbrical ligament
what is g?
- flexor digitorum profundus tendon
what is covering the intrinsic hand muscles, but beneath the flexor retinaculum, aponeurosis and blood supply?
- fibrous digital sheath on fingers and synovial sheath connecting them/beneath
what is the palmar aponeurosis?
central part of the deep fascia of the palm which is a highly specialized thickened structure with little mobility.
It is triangular in shape and it covers the underlying neurovascular and tendon structures
what is the structure/relationship of the flexor digitorum profundus and superficialis?
- superficialis inserts by splitting the tendon on the middle phalanx of digits 2-5
- profundus passes through the split to insert on the distal phalanx of digits 2-5 ( like a banana peel/corn)
where does the flexor digitorum superficialis insert?
- -inserts by splitting tendon on middle phalanx of digits 2-5
where does the flexor digitorum profundus insert?
- passes through split superficialis and inserts on distal phalanx of digits 2-5
where does the flexor pollicis longus insert?
- inserts on distal phalanx of digit 1
how do you test the flexor digitorum profundus?
hold down middle phalanx of finger and try to flex tip of finger
how do you test the flexor digitorum superficialis?
- hold down 2nd and 4th digit and try to flex 3rd digit
what is the origin of the palmaris brevis?
- palmar aponeurosis (medial side)
what is the insertion of the palmaris brevis?
- dermis of medial margin of hand
what is the innervation of the palmaris brevis?
- superficial branch of ulnar nerve
what is the action of the palmaris brevis?
- deepens cup of hand, improving grip
what are the main ligaments of the hand (7)?
- flexor retinaculum (roof of carpal tunnel)
- extensor retinaculum
- palmar / volar ligaments
- collateral ligaments
- annular/cruciate ligaments
- deep and superficial transverse metacarpal ligaments
what is the extensor retinaculum?
- thickened part of the antebrachial fascia that holds the tendons of the extensor muscles in place
it is located on the back of the forearm, just proximal to the hand.
what are the palmar / volar ligaments/plates?
thick, dense fibrocartilaginous structures on the palmar side of metacarpal and interphalangeal joints
what are the collateral ligaments?
- on the sides of the phalanges (both sides) connecting the phalanges to the next
what are the 3 thenar muscles?
- opponens pollicis
- flexor pollicis brevis
- abductor pollicis brevis
(FAO from top of thumb to bottom) - creates bulge called thenar eminence
- all innervated by median nerve
what is the origin of the opponens pollicis?
- tubercle of trapezium and flexor retinaculum
what is the origin of the flexor pollicis brevis?
- tubercle of trapezium and flexor retinaculum
what is the origin of the abductor pollicis brevis?
- tubercles of scaphoid, trapezium and flexor retinaculum
what is the insertion of the opponens pollicis?
- lateral margin of 1st metacarpal
what is the insertion of the flexor pollicis brevis?
- base of proximal phalanx of thumb
what is the insertion of the abductor pollicis brevis?
- lateral side of proximal phalanx of thumb
what is the innervation of the thenar muscles?
- recurrent branch of the median nerve (C8,T1)
what is the action of the opponens pollicis?
- opposes thumb by medially rotating and flexing
what is the action of the abductor pollicis brevis
-abducts thumb (away from index finger)
what is the action of the flexor pollicis brevis?
flexes thumb = bring towards palm
what are the hypothenar muscles?
- opponens digiti minimi
- flexor digiti minimi brevis
- abductor digiti minimi
- produces bulge called hypothenar eminence (base of pinky)
- all innervated by ulnar nerve
what is the innervation of the hypothenar muscles?
- deep branch of ulnar nerve (C8, T1)
what is the origin of the opponens digiti minimi?
- hook of hamate and flexor retinaculum
what is the insertion of the opponens digiti minimi?
- medial margin of 5th metacarpal
what is the action of the opponens digiti minimi?
- rotates metacarpal of little finger towards palm (opposition)
what is the origin of the abductor digiti minimi?
- pisiform and tendon of flexor carpi ulnaris
what is the insertion of abductor digiti minimi?
- base of 5th proximal phalanx
what is the action of the abductor digiti minimi?
- abducts the pinky
what is the origin of the flexor digiti minimi brevis?
- hook of hamate and flexor retinaculum
what is the insertion of the flexor digiti minimi brevis?
- base of 5th proximal phalanx
what is the action of the flexor digiti minimi brevis?
- flexes MCP joint of little finger
what are the intrinsic hand muscles?
- adductor pollicis
- lumbricals
- interossei
what is the origin of the adductor pollicis?
- transverse head = from shaft of metacarpal 3
- oblique head = from capitate and bases of metacarpal 2 and 3
what is the insertion of adductor pollicis?
- base of proximal phalanx and extensor hood
what is the innervation of the adductor pollicis?
- deep branch of ulnar nerve (C8,T1)
what is the action of the adductor pollicis?
- adducts the thumb (in towards index finger)
what is the origin of the lumbricals?
- tendon of the flexor digitorum profundus (each finger)
what is the insertion of the lumbricals?
- extensor hoods of each finger
what is the innervation of the lumbricals?
- all innervated by C8,T1
- digits 2,3 = digital branches of median nerve
- digits 4,5 = deep branch of ulnar nerve
what is the action of the lumbricals?
- flexion of the MCP joint and extension of IP joints
what are the 2 groups of interossei muscles?
- dorsal and palamr
what is the origin of the interossei muscles?
- lateral and medial surfaces of metacarpals
what is the insertion of the interossei muscles?
- extensor hood and proximal phalanx of each finger
what is the innervation of the interossei muscles?
- deep branch of the ulnar nerve
what is the action of the interossei muscles?
dorsal = abducts finger at MCP joint
palmar = adducts finger at MCP
and helps to flex MCP and extend IP joint
how do the lumbricals and interossei work together?
- itersossei = on sides of fingers
- lumbricals = on palmar side of fingers
- they both connect to the extensor hood which extends to the end of the finger
- when they both contract, it pulls on it and extends the IP joint
what is the anatomical snuff box?
-triangular depression on the dorsum of the hand at the base of the thumb. The anatomical snuffbox is visible with ulnar deviation of the wrist and extension and abduction of the thumb
what is the lateral border of the anatomical snuff box?
- tendons of abductor pollicis longus and extensor pollicis brevis
what is the medial border of the anatomical snuff box?
- tendon of extensor pollicis longus
what is the floor of the anatomical snuffbox?
- scaphoid and trapezium, tendons of extensor carpi radialis longus and brevis
what is the contents of the anatomical snuffbox?
- radial artery, cephalic vein, superficial branches of the radial nerve
what are the 2 arteries going into the hand and which one is primary/secondary?
ulnar and radial artery
- ulnar = primary
- radial = secondary
what are the 2 blood vessel arches in the hand and what are their branches (palmar side)?
superficial palmar arch = common and proper palmar digital arteries
- deep palmar arch = palmar metacarpal anastamoses, princeps pollicis artery and radial indicis artery
what are the dorsal arteries of the hand?
radial artery from front round thumb/scaphoid –> dorsal carpal artery –> dorsal metacarpal arteries –> dorsal digital artery
what is a?
superficial palmar branch of the radial artery
what is b?
common palmar anastamoses
what is c?
proper palmar digital anastamoses
what is d?
superficial palmar arch
what is e?
deep palmar arch
what is f?
radialis indicis artery
what is g?
dorsal metacarpal artery
what is h?
dorsal carpal arch
what are the veins in the hand?
- dorsal side
- cephalic vein (lateral/thumb), basilic vein (medial/pinky)
- dorsal venous arch
what are the nerves and branches in the hand?
- ulnar nerve = deep and superficial branch
- median nerve = recurrent branch and palmar digital nerves
- radial nerve = superficial branch
what does the deep branch of the ulnar nerve supply in the hand?
- mostly motor
- all hand muscles except the 3 thenar muscles and 2 lateral lumbricals
where does the ulnar nerve run in the hand?
- enters the hand through guyon’s canal between the pisiform and the hamate bones (with ulnar artery, medial/pinky)
what does the superficial branch of the ulnar nerve supply in the hand?
- mostly sensory
- digits 1/2 4 and 5 and palmar and dorsal skin below
where does the median nerve run in the hand?
- through the carpal tunnel
what does the recurrent branch of the median nerve supply?
- motor to thenar muscles
what does the palmar digital branch of the median nerve supply?
- motor to 2 lateral lumbricals
- sensory to palmar surface and top of dorsal surface of digits 1,2,3 and 1/2 4
where does the radial nerve run in the hand?
- enters hand by passing over anatomical snuffbox
what does the superficial branch of the radial nerve supply?
- sensory to lateral part of palm and dorsal aspect of digits 1,2,3 but not nail beds/distal end of fingers
what muscles and nerve supply action A?
- interosseous and lumbricals
- deep branch of ulnar nerve
what muscles and nerves supply action b?
- palmar interosseous
- deep branch of ulnar nerve
what muscles and nerves supply action c?
- thenar muscles
- median nerve
what are the different types of wrist fractures(7)?
- scaphoid
- Colle’s
- Smith’s
- Barton’s
- Chaffeur’s
- Greenstick
- ulnar styloid
what is a scaphoid fracture, what is it caused by and what is its complication?
- fracture of the scaphoid carpal bone (below the thumb) usually due to falling onto outstretched hand
- fracture could cut the radial artery which lies next to it, causing avascular necrosis
what is a Colle’s fracture and what are some complications?
- fracture of distal end of the radius
- the fracture is often angled upwards and away from the origin, broken bone points backwards
- fracture could compress or damage median nerve = benedictions hand (can flex first 3 digits) / carpal tunnel syndrome
- Extensor pollicis longus tendon may also be damaged = cannot extend thumb
what is a Smith’s fracture and what are some complications?
- fracture of distal end of the radius, broken bone points forward
- fracture could compress or damage median nerve =benedictions hand (can flex first 3 digits) / carpal tunnel syndrome
what is a Barton’s fracture and what are some complications?
- a compression injury with a marginal shearing fracture of the distal radius
- The most common cause of this injury is a fall on an outstretched, pronated wrist
- could lead to carpal tunnel syndrome
what is a chaffeur’s fracture?
- break of the radial styloid
- also called Hutchinson fracture
What is a greenstick fracture?
- when a bone bends and cracks instead of completely snapping
- mostly occurs in children as their bones are more flexible
what is an ulna styloid fracture?
when the styloid (sticking out end part) is broken on the ulna
what happens to the hand when the median nerve is damaged?
- median nerve palsy
- innervated thenar muscles and flexor muscles of digits 1-3 and 2 lateral lumbricals, so first 3 digits can no longer flex = benediction hand
- may also have numbness in sensory area
what happens to the hand when the ulnar nerve is damaged?
- hyperextension of MCP joints and flexion of IP joints
- claw hand
-tingling in fingers 4 and 5, weak grip strength, pain and sensitivity on the ulnar side of the forearm, wrist and hand, muscle atrophy, clawing of digits 4 and 5
what happens to the hand when the radial nerve is damaged?
- radial nerve supplies all posterior muscles in forearm = extensors and also sensory to back of hand and forearm
- no longer extend wrist = wrist drop
- numbness/tingling on back of hand
describe the different layers of fascia in the hand
- palmar fascia consists of fibrous connective tissue which thickens in the centre of the hand forming palmar aponeurosis (which is continuous with palmaris longus tendon and flexor retinaculum)
- palmar aponeurosis then fans out to form fibrous digital sheaths, which cover synovial sheaths containing tendons on fingers
