Peripheral Nerve Flashcards
Radial impingement sites
Triangular space
Radial groove
Elbow
Radial Triangular space
Teres major, tricep (long head), humerus
Weakness of elbow extension, weakness of wrist extension
Loss of tricep reflex
Loss of sensation of entire posterior arma nd froearm (exceot lateral forearm- musculocutaneous)
Loss of sensation lateral 3 1/2 fingers to DIP Jt
Radial groove
Often due to compression from humeral #, tourniquets or blood pressure cuff
Entrapment below triceps
Weakness of wrist extension
Loss of sensation to posterior lateral 3 1/2 fingers
Radial Elbow
Deep branch of radial nerve compressed by # of proximal radius or as it passes through two planes of supinator muscle
Weakness of thumb and MCP extension
Musculocutaneous impingement sites
Axillary fold or coracobrachialis belly
Musculocutaneous impingement S+S
Weakness of elbow flexion
Loss of cutaneous sensation to ant/lat forearm
Loss of bicep reflex
Axillary impingement sites
Quadrangular space- teres minor, major, triceps (long head), humerus
Axillary impingement S+S
Weakness in deltoid + teres minor muscles- results in weak abduction of arm
Loss of cutaneous sensation to superior posterior/lateral arm
Median impingement sites
Elbow
Passage of nerve through two heads of hypertonic pronator teres muscle
Wrist
Median Elbow
Occasionally compression due to sleeping on elbow, or medial supracondylar #
Weakness of forearms + wrist pronation
Weakness of wrist flexion
Ape hand deformity (atrophy of thenar muscles)
Loss of sensation to palm and palmar surface of lat 3 1/2 fingers
Median Pronator teres muscle
Throbbing/aching P in wrist and forearm
Weakness in gripping small objects
P with pronation
P with wrist flexion
Ape hand
Same loss of sensation
Median Wrist
Most commonly CTS, maybe lacerations or puncture wounds
Ape hand deformity
Loss of sensation to 3 1/2 lateral fingers, NOT palm- helps differentiate CTS ti impingement further up
Ulnar sites of impingement
Cubittal tunnel
Wrist
Ulnar Cubittal tunnel
Cubittal tunnel syndrome
Compression due to # at medial epicondyle or sustained pressure in aconeus muscle
Weakness of wrist flexion (ulnar side)
Claw hand deformity
Loss of sensation to medial 1 1/2 finges
The cubital tunnel
Tendinous arch joining humeral head and ulnar heads of flexor carpi ulnaris
Inflam to flexor carpi ulnaris may compress ulnar nerve