Boatright J R, Kiebzak G M
Miller Orthopaedic Clinic, Charlotte, NC 28203, USA.
J Hand Surg Am. 1997 Sep;22(5):849-52. doi: 10.1016/S0363-5023(97)80080-9.
The relative contributions of the abductor pollicis longus (APL) and abductor pollicis brevis (APB) to thumb abduction strength (TAS) were determined after a selective nerve block in 21 normal volunteers. The median nerve was anesthetized (blocked) at the wrist. Needle electromyography verified paralysis of the APB and usually the opponens pollicis; in 6 study subjects, the superficial head of the flexor pollicis brevis (FPB) was also paralyzed. The APL, innervated by a branch of the posterior interosseous nerve, remained functionally intact. TAS was measured by a mechanical device before and after median nerve block. Median nerve block at the wrist resulted in a dramatic decrease in TAS in all volunteers. The mean loss of TAS was 70.3% in men and 74.3% in women. Postblock TAS tended to be greater in those subjects with retained function of the FPB. This study verifies that TAS is primarily a function of the APB.
在21名正常志愿者接受选择性神经阻滞后，确定了拇长展肌（APL）和拇短展肌（APB）对拇指外展力量（TAS）的相对贡献。正中神经在腕部被麻醉（阻滞）。针极肌电图证实APB以及通常的拇对掌肌麻痹；在6名研究对象中，拇短屈肌（FPB）的浅头也麻痹。由骨间后神经分支支配的APL功能保持完好。在正中神经阻滞前后，用机械设备测量TAS。腕部正中神经阻滞导致所有志愿者的TAS显著下降。男性TAS的平均损失为70.3%，女性为74.3%。在FPB功能保留的受试者中，阻滞后的TAS往往更大。本研究证实TAS主要是APB的功能。
