hand/wrist LOs Flashcards
abductor digiti minimi
- BL: pisiform > ulnar side of base of proximal phalanx of 5th digit
- action: abducts 5th digit
- innervation: deep branch of ulnar nerve
- SC: C8-T1
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abductor pollicis brevis
- BL: transverse carpal ligament > radial side of base of proximal phalanx of thumb
- action: abducts thumb
- innervation: recurrent branch of median nerve
- SC: C6-T1
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adducutor pollicis
- BL: capitate, 2nd and 3rd metacarpals (oblique head), palmar aspect of 3rd metacarpal (transverse head) > base of proximal phalanx of thumb
- action: adducts thumb
- innervation: deep branch of ulnar nerve
- SC: C8-T1
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dorsal interossei
- BL: adjacent sides of metacarpals > proximal phalangeal bases, dorsal digital expansions of digits 2-4
- actions: abduct MCP, flex MCP, extends IP (digits 2-4)
- innervation: deep branch of ulnar nerve
- SC: C8-T1
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flexor digiti minimi brevis
- BL: hamate > ulnar side of base of proximal phalanx of 5th digit
- action: flexes MCP of 5th digit
- innervation: deep branch of ulnar nerve
- SC: C8-T1
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flexor pollicis brevis
- BL: transverse carpal ligament, trapezium > radial side of base of proximal phalanx of thumb (deep bead blends with opponens pollicis)
- action: flexes MCP of thumb
- innervation: recurrent branch of median nerve (superficial head), deep branch of ulnar nerve (deep head)
- SC: C6-T1 (superficial head), C8-T1 (deep head)
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lumbricals
- BL: tendons of flexor digitorum > radial side of dorsal digital expansions of digits 2-5
- action: flexes MCP 2-5, extends IP 2-5
- innervation: median nerve (1, 2), deep branch of ulnar nerve (3, 4)
- SC: C7-T1 (1, 2), C8-T1 (3,4)
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opponens digiti minimi
- BL: hook of hamate > ulnar margin of shaft 5th metacarpal
- action: opposition of 5th digit to thumb
- innervation: deep branch of ulnar nerve
- SC: C8-T1
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opponens pollicis
- BL: transverse carpal ligament, trapezium > palmar surface of first metacarpal
- action: opposition of thumb to fifth digit
- innervation: recurrent branch of median nerve
- SC: C6-T1
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palmar interossei
- BL: palmar aspects of metacarpals 2, 4, 5 > dorsal digital expansions of digits 2, 4, 5
- action: adducts MCP, flex MCP, extend IP (2, 4, 5)
- innervation: deep branch of ulnar nerve
- SC: C8-T1
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distal radio-ulnar joint
pivot/trochoid
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radiocarpal joint
ellipsoidal/condyloid
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thumb carpometacarpal joint
sellar/saddle
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digits 2-5 carpometacarpal joint
plane/gliding
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metacarpophalangeal joint
ellipsoidal/condyloid
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interphalangeal joint
ginglymus/hinge
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transverse carpal ligament
- attachments: pisiform, hook of hamate > scaphoid, trapezium
- function: prevent bowstringing of tendons of flexor pollicis longus, flexor digitorum superficialis, flexor digitorum profundus mm.
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collateral ligaments of metacarpophalangeal joints
- attachments: head of metacarpals > base of adjacent proximal phalanx
- function: stabilizes metacarpophalangeal joints
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collateral circulation of hand
- ulnar:
- superficial palmar arch
- common palmar digital aa. > proper palmar digital aa.
- deep palmar branch
- superficial palmar arch
- radial:
- princeps pollicis
- radialis indicis
- deep palmar arch
- palmar metacarpal (to common palmar digital aa.)
- superficial palmar branch
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surface features of hand and wrist
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carpal bones
- some lovers try positions that they can’t handle
- scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate
- proximal: scaphoid, lunate, triquetrum, pisiform
- distal: trapezium, trapezoid, capitate, hamate
actions/motions of the wrist
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transverse carpal ligament/flexor retinaculum
- attachments: hook of hamate, pisiform > trapezium, scaphoid
- function:
- thenar and hypothenar mm. attachment
- maintains carpal arch
- prevents bowstringing of flexor tendons
- protects median n.
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triangular fibrocartilage complex (TFCC)
- articular disc: primary structure
- triangular shape
- shock absorption
- like meniscus in knee (no good blood supply)
- fibrocartilaginous: degenerates with overuse and aging
- dorsal/volar radioulnar ligament
- ulnar collateral ligament
- ECU sheath
- ulnotriquetral ligament
- ulnolunate ligament
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compartments formed by extensor retinaculum and tendons found within each
- abductor pollicis longus, extensor pollicis brevis (APL, EPB)
- extensor carpi radialis longus/brevis (ECRL, ECRB)
- extensor pollicis longus (EPL)
- extensor digitorum, extensor indicis (ED, EI)
- extensor digiti minimi (EDM)
- extensor carpi ulnaris (ECU)
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bones and joints of hand
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actions/motions of fingers and thumb
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structure of palmar fascia and palmar digital sheaths
- palmar fascia: continuous with antebrachial fascia
- includes thenar fascia, hypothenar fascia, palmar aponeurosis
- palmar digital sheaths: pulleys
- annular: straight (A1-A5)
- cruciate: crossed (C1-C3)
- functions: maintain relationship of flexor tendons to bone
- prevents bowstringing of tendons (A2-A4 are most critical)
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juncturae tendinae
- structure: intertendinous connections of extensor digitorum (ED)
- number/location vary between/among individuals
- function: distributes forces
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intrinsic vs. extrinsic muscles
- intrinsic: originate and insert on hand
- thenar, hypothenar, adductor pollicis, lumbricals, interossei
- extrinsic: originate in forearm and insert on hand
- flexor digitorum profundus, flexor digitorum superficialis, flexor pollicis longus, abductor pollicis longus, extensor pollicis longus, extensor digitorum, extensor indicis, extensor digiti minimi
location and function of ligaments of fingers
- radial/ulnar collateral: gives radial/ulnar stability
- dorsal surface > volar surface
- taut in flexion (lengthens), lax in extension (shortens)
- at MP, PIP, DIP
- dorsal surface > volar surface
- volar plate: prevents finger hyperextension
- palmar ligament/plate
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muscles that attach to extensor mechanism/hood/expansion and how they move finger
- extensor hood: tendon covering dorsal digits, cable system to extend MPs and IPs
- allows lumbricals and dorsal/palmar interossei to assist in MP flexion
- components: extensor digitorum, juncturae tendinae, central slip, sagittal bands, lateral bands, transverse retinacular ligament, oblique retinacular ligament, terminal tendon
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radial nerve supply
- triceps brachii (long, lat, med), brachioradialis, ECRL, ECRB, anconeus, supinator, EDM,ECU, APL, EPL, EPB
- posterior portion of arm and forearm, radial dorsum of hand
- no motor in hand, only extensors/supinators
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median nerve supply
- pronator teres, FCR, PL, FDS, FDP, FPL, pronator quadratus, APB, FPB, OP, lumbrical 1, lumbrical 2
- cutaneous: radial side of palm (digits 1-4), ends of digits 1-2
- flexors/pronators, radial hand
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ulnar nerve supply
- FCU, FDP, AP, FPB (deep head), PB, abductor/flexor/opponens digiti minimi, lumbricals 3/4, interossei
- cutaneous: dorsal and volar digits 3-4, palmar aspect
- mostly hand
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anatomical snuff box
- dorsal border: extensor pollicis longus (EPL)
- volar border: abductor pollicis longus, extensor pollicis brevis (APL, EPB)
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underlying anatomy of carpal tunnel syndrome
- median nerve compression at wrist under flexor retinaculum
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oblique head of adductor pollicis
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transverse head of adductor pollicis
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abductor digiti minimi
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