Adductor Pollicis

Ulnar nerve—monitor response of the adductor pollicis (thumb)... 

Heier T, Caldwell JE, Sessler DI, Miller RD. The effect of local surface and central cooling on adductor pollicis twitch tension during nitrous oxide/isoflurane and nitrous oxide/fentanyl anesthesia in humans. Anesthesiology 1990 72(5) 807-11. 

Laycock JR, Smith CE, Donati F, Bevan DR. Sensitivity of the adductor pollicis and diaphragm muscles to atracurium in a hemiplegic patient. Anesthesiology 1987 67(5) 851-3. 

Assessment of neuromuscular block usually is performed by stimulation of the ulnar nerve. Responses are monitored from compound action potentials or muscle tension developed in the adductor pollicis (thumb) muscle. Responses to repetitive or tetanic stimuli are most useful for evaluation of blockade of transmission. Thus, stimulus schedules such as the train of four and the double burst or responses to tetanic stimulation are preferred procedures. Rates of onset of blockade and recovery are more rapid in the airway musculature (jaw, larynx, and diaphragm) than in the thumb. Hence, tracheal intubation can be performed before onset of complete block at the adductor pollicis, whereas partial recovery of function of this muscle allows sufficient recovery of respiration for extubation. 

Harris ML, Luo YM, Watson AC, et al. Adductor pollicis twitch tension assessed with magnetic stimulation of the ulnar nerve. Am J Respir Crit Care Med 2000 162 240-245. 

The flexor pollicis longus tendon traverses the thenar eminence between the superficial and deep bellies of the flexor pollicis brevis muscle. It then enters the osteofibrous canal of the thumb to insert at the volar aspect of the base of the distal phalanx. At the metacarpal head level, this tendon courses between two sesamoid bones, one (lateral) included in the combined tendon of the flexor pollicis brevis and abductor pollicis longus, the other (medial) in the adductor pollicis tendon. 

The adductor pollicis muscle is a fan-shaped muscle supplied by the deep branch of the ulnar nerve with two heads (oblique and transverse) of origin between which the radial artery passes. The oblique head arises from the second and third metacarpals... 

Fig. 11.60. Gamekeeper s thumb. Schematic drawing illustrates the mechanism of ulnar collateral ligament tear. Typically, the ligament rupture is the end result of a vigorous valgus stress (curved arrow) applied on the metacarpophalangeal joint leading to excessive tension (black arrows) on the ligament. Note the relationship of the ulnar collateral ligament (in black) with the extensor poUicis longus tendon (epl) and the adductor pollicis aponeurosis (open arrows)...

First dorsal (DI) If the electrode is inserted too deeply it will be in the adductor pollicis. 

Second dorsal (T>2) If the electrode is inserted too deeply and it is angled in a radial direction it will be in the first volar interosseus if deeper it will pierce the aponeurosis, and it will be in the adductor pollicis. 

First volar If electrode is inserted too superficially it will be in the second dorsal interosseus if inserted too deeply, it will be in adductor pollicis. 

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