Supinator
O = lateral epicondyle and ulnar I = upper third of radius a = supinates forearm Inn = deep branch of radial nerve
First volar interosseous muscle
O = length of second MC I = base of proximal phalanges A = adducts flexes mcp and extends ip's of IF Inn = deep branch of ulnar nerve
Extensor Carpi Ulnaris
O = lateral epicondyle common extensor tendon I = base of 5 th MC A = extends wrist and ulnar deviates wrist inn = PIN (radial nerve)
Abductor pollicis Brevis
O = transverse carpal ligament, scaphoid and trapezium I = radial base of prox phalanx of thumb and thumb ext A = abducts thumb: assists in opposition and extension of thumb Inn = recurrent branch of median nerve
APB is the strongest muscle in opposition
First dorsal interosseous
O = radial edge of 2nd MC I = base of proximal phalanx of IF A = abduct finger Inn = deep branch of ulnar nerve
Adductor Pollicus
O = transverse head - anterior body third MC oblique head- bases of the second and third MC and trapeziod and capitate I = ulnar side of prox phalanx of thumb A = adducts thumb Inn = deep branch of ulnar nerve (t1)
Extensor Carpi radialis Brevis
O = common ext tendon I = base of third MC A = wrist extension and radial deviation Inn = radial
Extensor pollicis Longus
O = middle third posterior ulnar and interosseous membrane I = first distal phalanx A= extension of thumb MCPJ AND IPJ Inn = PIN radial nerve
Palmaris Brevis
O = flexor retinaculum and palmar aponeurosis I = Palm A= pulls skin over hypo thenar eminence deepens cup of hand and improves grip Inn = superficial branch of ulnar nerve
Pronator quadratus
O =medial anterior surface of ulnar
I = lateral anterior surface of radius
A= pronation of forearm
Inn= AIN median nerve
Extensor indices proprius
O= posterior distal third of ulnar and interosseous membrane I = extensor hood of IF A = extends IF and wrist Inn = PIN
Brachioradialis
O = lateral supra condylar ridge of humerus
I = distal radius radial styloid
A = flexion of elbow and supination when elbow extended
Inn = radial nerve
When pronated it is more active during flexion as biceps brachii is at a mechanical disadvantage
Lumbricales
O= FDP TENDONS I = extensor expansion of EDC A= extend IPJ's ( weak MCPJ flexor so)