post forearm Flashcards
muscles in superficial lat layer (3)
- Brachioradialis
- Extensor carpi radialis longus
- extensor carpi radialis brevis
muscules in superficial posterior layer (3)
- extensor digitorum
- Extensor digiti minimi
- extensor carpi ulnaris
Muscues in deep extensor layer (5)
- supinator
- abd pollicis longus
- extensor pollicis brevis
- ext pollicis longus
- extensor indices
floor of the anatomical stuff box (4)
- scaphoid
- trapezium
- ECRL tendon
- ECRB tendon
what muscle is the most prox for a deep radial n entrapment
deep radial n
what makes up extensor expansion
3 bands-> one central and 2 collateral connected by circular fibres called the hood
what can rupture the extensor expansion
hyperfexion of distal interphalangeal J
med and lat borders of anatomical stuff box
lat= Abductor pollicis longus + extensor pollicis brevis tendons
Med=extensor pollicis longus tendon
roof of anatomical snuff box (3)
superficial fascia
skin
superficial radial n branches
Contents of anatomical snuff box
Radial a +v
tendons of extensor expansion lat to med (6)
1- abd pollicis br + ext pollicis brev
- Ext carpi radialis longus + brevis
- ext pollicis longus
- ext digitorum + ext indicis
- ext digiti minimi
- ext carpi ulnaris
path of radial n and its two terminal br
radial n runs in radial groove into the ant arm into the cubital fossa, ant to lat epicondyle and split into deep and superfical radial
where does the superfical radial n run and what does it supply
- runs bw brachioradialis and ECRL on lat forearm
- supplies skin over snuffbox and distal pollex
when does the deep radial n change names to post interosseus n
after it emerges from distal 1/3 of supinator
the deep radial n will innervate what muscles before changing names to post interosseus (5)
ECRB Supinator ECU Ext digitorum Ext dig min
main branch of radial n innervates (2)
brachiradialis
ECRL
what does the superficial radial n supply is dorsal hand
lat 3.5 fingers
what does the dorsal branch of ulnar n supply
med 1.5 fingers
3 areas radial n can be injured
Axilla
Radial groove
Supinator
What is the cause of a axilla injury and sensory and motor impaiments
-from crutches, lymph nodes
weakness of ext of arm, forearm, hand, fingers (wrsit drop)
Parasthesia at post aspect of arm, forearm, dorsum, lat 3.5 fingers
what is cause of radial groove injury and what are the deficits
fracture of humerus, arm rested on sharp chair
long head of tri and post cuteneous are spared
what is cause of supinator m injury and what are the deficits
-Entrapment neuropathy, muscle hypertension
no sensory
-extensors of forearm, digits involved
ECRL, brachioradialis and brachialis spared
mallet/baseball finger mech and result
mech- servere tension on ext tendons since distal interphalangeal j are forced into extreme flexion
result- extensior expansion is ruptured and distal phalanx is stuck flexed
what is a synovial cyst of the wrist and what is it commonly attached to
non tender cystic swelling on dorsum of hand commonly attached to ECRB and ECRL
where can the radial n be impinged to cause wrist drop
- fracture of humeral shaft
2. entrapment by supinator
