Forearm Flashcards
What innervates the muscles of the deep flexor compartment of the forearm?
AIN
What is the innervation of flexor digitorum profundus?
Radial 2: AIN Ulnar 2: ulnar
What is the innervation of FPL?
AIN
What is the innervation of pronator quadratus?
AIN
What innervates the superficial flexor compartment of the forearm?
Median nerve
Where does ECRL insert?
2nd metacarpal
Where does ECRB insert?
3rd metacarpal (it’s shorter than ECRL)
Where does brachioradialis insert?
styloid process
What innervates ECRB?
PIN
What innervates the mobile wad, aside from ECRB?
radial nerve
What innervates ECU?
PIN
What is the Space of Parona?
Potential space in the forearm between FPL, FDP and pronator quadratus
What is Wartenberg’s Syndrome
AKA Cheiralgia paresthetica
Superficial radial nerve compression between ECRL and BR, commonly from fascial band where it emerges from these muscles ~9cm from the wrist
Presents with pain or dysthesia on dorsal radial forearm radiating to thumb. - Tinel’s sign over superficial radial nerve is most common finding
Differential
De Quervain’s tenosynovitis
pain is not aggravated by wrist pronation, unlike Wartenberg Syndrome
Lateral antebrachial cutaneous nerve (LACN) neuritis
positive Tinel’s sign over LACN can be mistaken for positive Tinel’s over superficial sensory radial nerve
Intersection syndrome
may have dorsoradial forearm swelling
symptom exacerbation and “wet leather” crepitus on repeated wrist flexion/extension
What are the boundaries of the radial tunnel?
- 5cm in length
- from the radiocapitellar joint extending PAST the proximal edge of the supinator
- lateral BR, ECRL, ECRB
- Medial - biceps tendon and brachialis
- floor - capsule of radiocapitellar joint
What 3 muscles in the extensor compartment of the forearm does the PIN not innervate?
the mobile wad (innervated by radial nerve proper)
ECRB (although this is variable)
ECRL
brachioradialis
