Hand Flashcards by Hannah P Erickson

Arches of hand

proximal transverse
distal transverse
longitudinal

How well did you know this?

Not at all

Perfectly

Proximal transverse arch

distal row of carpal bones
capitate is keystone

How well did you know this?

Not at all

Perfectly

Distal transverse arch

metacarpophalangeal joints
keystone was MC 2 and 3

How well did you know this?

Not at all

Perfectly

Longitudinal Arch

curve of 2nd, 3rd rays
keystone: MC2 and 3

How well did you know this?

Not at all

Perfectly

Carpal Tunnel

Transverse carpal ligament
passageway for median nerve and tendons of extrinsic digit muscles
prevents bowstringing of tendons out of carpal tunnel

How well did you know this?

Not at all

Perfectly

Transverse carpal ligament

connected to 4 points, pisiform, hook of hamate, scaphoid, trapezium
converts palmar concavity into carpal tunnel

How well did you know this?

Not at all

Perfectly

Radiocarpal joint makeup

lunate, scaphoid, triquetrum (sometimes), radius
80% compression forces pass through scaphoid/luante

How well did you know this?

Not at all

Perfectly

Midcarpal joint makeup

articulation between proximal and distal row of carpal bones
medial and lateral compartments

How well did you know this?

Not at all

Perfectly

Intercarpal joints makeups

13 articulations

How well did you know this?

Not at all

Perfectly

Medial Midcarpal joint convex/concave heads

convex head of capitate and hamate –> fit into concave triquetrum, lunate, medial scaphoid

How well did you know this?

Not at all

Perfectly

Lateral Midcarpal joint convex/concave heads

convex scaphoid fitting into concave trapezoid and trapezium
less motion then medial compartment

How well did you know this?

Not at all

Perfectly

Wrist ligaments

maintain natural intercarpal alignment and transferring forces across carpals

help to contribute to proprioception
signal travel to wrist muscles to reflexively protect the wrist

intrinsic and extrinsic

How well did you know this?

Not at all

Perfectly

Extrinsic ligaments

dorsal radiocarpal
radial collateral
palmar radiocarpal
TFCC

How well did you know this?

Not at all

Perfectly

Dorsal radiocarpal ligament

distal radius to lunate and triquetrum
major contributor to arthrokinematics
rich innervation

How well did you know this?

Not at all

Perfectly

Radial collateral ligament

radial styloid to scaphoid

How well did you know this?

Not at all

Perfectly

Palmar radiocarpal ligament

several ligaments known as 1
greater stability than dorsal
radial-scaphate, radial-lunate
taut at extension, guides arthrokinematics

How well did you know this?

Not at all

Perfectly

Triangular Fibrocartilage Complex

5 structures occupy space
bind radius & ulna, permits pronation and supination
contains an articular disc
reinforced by surrounding ligaments

made up of UCL, palmar radioulnar, triangular fibrocartilage, dorsal radioulnar, ECU tendon

How well did you know this?

Not at all

Perfectly

Intrinsic ligaments of wrist

short, intermediate, long

How well did you know this?

Not at all

Perfectly

Wrist Joint Type

Condyloid
2 degrees of freedom
axis of rotation through capitate

How well did you know this?

Not at all

Perfectly

Combined motions of wrist

Natural path combines both planes of motion
extension & radial deviation, flexion & ulnar deviation

ADLs use these motions

How well did you know this?

Not at all

Perfectly

Joints of the wrist

called the central column, which is made up of three separate joints
radiocarpal –> L/R
midcarpal –> C/L
Carpometacarpal

How well did you know this?

Not at all

Perfectly

Flexion/Extension of Wrist

Vex on Cave
radiocarpal on midcarpal

roll = palmar
slide = dorsal
opposite roll/slide for extension

How well did you know this?

Not at all

Perfectly

Closed pack position of wrist

full extension

How well did you know this?

Not at all

Perfectly

Ulnar/Radial deviation

Vex on Cave

Ulnar deviation is l/s/t on radius, capitate on l/s
Roll –> ulnar
Slide –> Radial
opposite for radial deviation

How well did you know this?

Not at all

Perfectly

Radial deviation is limited by....

ulnar tilt

85% of midcarpal of movement during radial deviation is due to...

styloid/ulnar tilt of radius

Proximal carpals ____ during ulnar deviation

extends

Proximal carpals ____ during radial deviation

flexes

Double V Ulnar deviation

palmar ulnocarpal and lateral palmar intercarpal ligaments tense causes more slide than roll

Double V Radial Deviation

Palmar radiocarpal and medial palmar intercarpal ligaments tense causes more slide than roll

CMC Joints 2-5, capsules

strengthened by dorsal and palmar carpometacarpal and intermetacarpal ligaments

Thumb joint

saddle joint of the body shape allows full opposition complex set of ligaments

CMC Joints 2-5 characteristics

Type of joint varies degrees of freedom: 0-2 Flex/Ext is main movement irregular and varied shapes

CMC joint 1 characteristics

saddle 2 degrees of freedom allows for abd/add and flex/ext

Abduction/Adduction in Thumb

Vex on Cave, MC on trapezium roll: palmar slide: dorsal opposite for adduction

Flexion/extension in thumb

Cave on vex MC on trapezium Roll/Slide: ulnar, involves IR opposite for extension, involves ER

Opposition of CMC

composite of primary motions phase 1 = abduction phase 2 = flexion (w/medial rotation)

Closed pack position of thumb

full opposition

MCP capsules (2-5)

Fibrous capsule have RCL and UCL, plus deep transverse metacarpal ligaments, palmar plates

MCP Joints 2-5 Characteristics

Condyloid Degrees of Freedom = 2 Flex/Ext, Abd/Add

Flexion/Extension MCP 2-5

Cave on Vex, proximal phalanx on MC Flexion --> Roll/Slide = palmar Extension --> Roll/slide = dorsal

Abduction/Adduction 2-5 MCP

cave on vex, proximal phalanx on MC Abduction --> Roll/slide = radial Adduction --> Roll/slide = ulnar

Characteristics of MCP 1

less ROM than other fingers abd/add limited, considered accessory motions have same arthrology as 2-5

IP Joints Ligaments

fibrous capsule, RCL, UCL, palmar plates

Characteristics of IP joints

hinge 1 degree Flexion/Extension

Flexion/Extension of IP joints

cave on vex, phalanx on phalanx Flexion --> roll/slide = palmar Extension --> roll/slide = dorsal

Primary Wrist Extensors

ECRL ECRB ECU

Secondary Wrist Extensors

ED EI EDM EPL secondary does not always indicate lower torque potential, just a secondary action

Muscles that have good MA for deviation and flex/ext

ECRL ECU EPB APL

Best positions for wrist extensors

when making a fist, wrist is generally held in 30-35° extension and 5-15° ulnar deviation optimizes length-tension relationship for extrinsic finger flexors

What position is grip strength maximized?

around 30 degrees of extension

Why is grip reduced in flexion?

finger flexors are at shortened position passive extensor torque of finger extensors

Weakness of Wrist Extensors

also can be a radial nerve injury difficulty producing max grip force wrist extensors cannot counteract wrist flexion

Wrist Flexor muscles, primary

FCR FCU Palmaris longus

Secondary wrist flexor muscles

FDP FDS FPL

Wrist flexors vs wrist extensors

wrist flexors can produce 70% greater torque than wrist extensors peak torque will occur 40° of flexion, wrist flexor MA rise sharply with increased flexion

Radial Deviators

ECRL APL many other secondary muscles

Ulnar Deviators

ECU FCU few other secondary muscles

Radial vs Ulnar Deviators

Radial deviators produce 15% greater torque compared to ulnar deviators muscles on both sides of M/L axis combine to produce radial and ulnar deviation torque despite wrist position

Extrinsic Digital Flexors

FDS FDP FPL larger MA at more proximal joints

Flexor digitorum superficialis

flexion of PIP joint, but can flex any joint it crosses

Flexor Digitorum profundus

flexion of DIP joint, flex any joint it crosses index DIP can flex independently

Fibrous Digital Sheath

5 annular pulleys and 3 cruciate pulleys common torn in rock climbers function is to hold tendons at close distance to joints

Tenodesis

active wrist extension = passive finger flexion active wrist flexion = passive finger extension there's a passive tension in muscles that causes this

Extrinsic Digital Extensors

Extensor Digitorum Extensor Indicis Extensor digiti minimi

Extensor mechanisms

central band lateral bands dorsal hood oblique retinacular ligament

Dorsal Hood

forms sling around base of proximal phalanx

Extrinsic Thumb Extensors

EPL EPB APL

Intrinsic Thenar Muscles of the Hand

APB FPB OP

Intrinsic hypothenar muscles

FDM ADM ODM palmaris brevis

FOOSH Injury

scaphoid fracture and scapholunate ligament tear

What angle are the extensors at the best length-tension?

30° puts them at midrange