hand- muscles and function Flashcards
thenar eminence
lasted rounded contour of the radial palm. precision movements and pincer grip. 4 muscles- FPB, ABP, opponenes pollicis, adductor pollicis
Hypothenar eminence
ADM, FDM, Opponen digit mini, palmaris brevis
medial rounded contour of ulna palm, grasping large objects, opposition of little finger, increasing the hallow of the palm
intermediate muscles
11 act on finger, 1 on thumb, dexterity- fine movements of fingers, grasp, maintain fist
4 palmer interossei, 4 dorsi interossei, 4 lumbricals
origin and insertions- FPB
Origin- flexor retinaculum, trapezium (deep- capitae, trapezoid)
insertion- radial side base proximal side base of phalanx of thumb
NS and action- FPB
median nerve T1, deep part- ulna nerve 1,
action- flexion at MCP, CMC, medial rotation of thumb
origin and insertion- abductor pollicis brevis
from- flexor retinaculum, scaphoid, trapezium
to- radial side of the bae of the proximal phalanx of thumb
NS and action- abductor pollicis brevis
median nerve T1,
action- abduction at CMC/ MCP joints of thumb
origin and insertion- opponenes pollicis
covered by APB and FPB, origin- flexor retinaculum, trapezium, to- whole length lateral half of anterior surface of 1st MC
NS and action- opponenes pollicis
NS median nerve T1, action- opposition involves movement of abduction/ MR/ flexion/adduction
origin and insertion- adductor pollicis
found in web space of thumb. origin- oblique head- tendon FCR, bases 2-3 MC, trapezoid, capitae
transverse- anterior surface shaft of 3rd MC
to- medial side base prox phalanx of thumb
origin and insertion- abductor digit minimi
from- pisiform, pisohamate, pisometacarpal ligament, tendon FCU to ulna side
to- proximal phalanx of little finger and DDE
NS and action abductor digiti minimi
NS- ulna nerve T1
Action- abd little finger, flexion MCP
origin and insertion- FDM
sometimes absent
origin- hook of hamate, flexor retinaculum
to base proximal phalanx of little fingere
NS and action- FDM
NS- ulna nerve T1
Action- flexion MCP joint
origin and insertions- opponens digiti minimi
origin- hook of hamate/ flexor retinaculum
insertion- shaft 5th mc
NS and action- opponens digiti minimi
NS- ulna nerve T1
Action- opposition 5th digit
origin and insertion- palmaris brevis
origin- flexor retinaculum and palmer aponeurosis
insertion- skin of palm into dermis
NS and action- palmaris brevis
ulna nerve C8, T1
Action- steadies and corrugates skin of palm to help with grip
dorsal interossei action and nerve supply
dorsal/ dual orgin, abduction (DAB)
ulna nerve C8, T1
1st DI- pulls index finger into abduction
2nd DI- pulls middle finger to abduction
3rd- return abducted middle finger to midline, then abduct opposite side
4th DI- abducts ringer finger from middle finger
Dorsal interossei origin and insertion
from adjacent sides of MC to proximal phalanx and DDE
palm interossei- action and nerve supply
action return digits to starting position (adduction) (PADD) ulna nerve C8 and T1 1st PI- adduction of thumb 2nd PI- index finger to middle finger 3rd PI- returns 4th MC to middle finger 4th- returns little finger to adduction
palmer interossei- origin and insertion
from MC to base of proximal phalanx and DDE (except middle finger)
function of interossei
extension of the IP, flexion at MCP joints, Abd/ add of MCPs
prevents hypo extension of the MCP, important in prehension activities
lumbricals origin and insertion
from tendon of FDP to DDE
radial 2 are unipennate
ulna 2- bipennate
lumbricals nerve supply
I and II meidan nerve C7,8 (radial 2)
III and IV ulna nerve C7, 8 (ulna 2)
dorsal hood
extensor hood- divides into 2 slips to base of distal phalanx and base of middle phalanx
allows one muscle to flex MCP and extend IP
The hand
an instrument of manipulation endowed with fine sensory discrimination
important to grip and manipulate in the activities of daily living and to inform us of our surroundings
5 functions of hand
manipulation, sensation, stability, protection, communication
motor innervation issues- posterior interosseous nerve
extrinsic muscles of the hand, wrist extensors, EPL and EPB and APL
dropped wrist- poor grip
motor innervation issues- ulnar nerve
hypothenar muscles, interossei and Add pollicis and half of FPB
Leads to clawed hand
motor innervation issues- median nerve
thenar muscles and finger flexors, loss of precision
nerve supply of hand
ulna nerve- both palmer and dorsal aspects of ulna side of hand- all 5th MC and half og 4th MC
3.5 digits and palm- median nerve, innervates dorsal aspect of half of medial 3.5 digits
remaining dorsal hand suppled by radial nerve
arches of hand
2 transverse arches
1 longitudinal arch
1 oblique arch
arches aid function of hand. they allow the hand to conform to objects
transverse arches- carpal arch (proximal)
formed by carpal bones, concave in shape and allows little movements- has key stone effect
transverse arches- metacarpal arch (Disatal)
formed by MC heads. it can widen and flatten, providing stability and mobility in hand
longitudinal arch
formed by carpal bones, MC bones, and the corresponding phalanges. it assumes a wide variety of shape
oblique arch
formed by thumb as it opposes each of finger
4 arches- from thumb tip to each finger
what is the palmer gutter (oblique arch)
palmer gutter- is a gutter which runs obliquely across the various oblique arches the palm. it passes from base if hypothenar eminence to head of 2nd MC
power grips- types
palmer grip, hook grip
power grips- palmer grips
involves whole hand. most powerful, thumb acts as buttress with fingers closing around the object. wrist in synergic extension, long flexors and thenar muscles are active.
power grips- adapted palmer grips
spherical grasp, cylindrical grasp
prehension
the use of hands and fingers to grasp, pick up objects
power grips and precision grips
precision grips
involves skillful placing of small objects between thumb and finger with manipulation, less strength of muscles contracting to produce and control fine movements, good sensation is essential to carry out precision movements
precision grips- pincer grip, and pad to pad grip
pincer grip- terminal opposition- tip of finger to tip of thumb- finest and most precise
pad to pad- sub terminal opposition- most common, pad to pad movements
precision grips- key grip, adduction grip
key- subterminal lateral opposition or lateral prehension- thumb pad to lateral side of middle phalanx of index finger- powerful and strongest
adduction grip- generally weakm with limited precision
