Toge Yasushi, Nishimura Yukihide, Basford Jeffrey R, Nogawa Takako, Yamanaka Midori, Nakamura Takeshi, Yoshida Munehito, Nagano Akira, Tajima Fumihiro
Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Wakayama, Japan.
Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota, United States of America.
PLoS One. 2013 Dec 18;8(12):e83565. doi: 10.1371/journal.pone.0083565. eCollection 2013.
To assess the separate effects of thumb and finger extension/flexion on median nerve position and cross-sectional area.
Ultrasonography was used to assess median nerve transverse position and cross-sectional area within the carpal tunnel at rest and its movement during volitional flexion of the individual digits of the hand. Both wrists of 165 normal subjects (11 men, 4 women, mean age, 28.6, range, 22 to 38) were studied.
Thumb flexion resulted in transverse movement of the median nerve in radial direction (1.2 ± 0.6 mm), whereas flexion of the fingers produced transverse movement in ulnar direction, which was most pronounced during flexion of the index and middle fingers (3.2 ± 0.9 and 3.1 ± 1.0 mm, respectively). Lesser but still statistically significant movements were noted with flexion of the ring finger (2.0 ± 0.8 mm) and little finger (1.2 ± 0.5 mm). Flexion of the thumb or individual fingers did not change median nerve cross-sectional area (8.5 ± 1.1 mm(2)).
Volitional flexion of the thumb and individual fingers, particularly the index and middle fingers, produced significant transverse movement of the median nerve within the carpal tunnel but did not alter the cross-sectional area of the nerve. The importance of these findings on the understanding of the pathogenesis of the carpal tunnel syndrome and its treatment remains to be investigated.
评估拇指和手指伸展/屈曲对正中神经位置和横截面积的单独影响。
采用超声检查评估腕管内正中神经在静息状态下的横向位置和横截面积，以及手部各手指主动屈曲时正中神经的移动情况。对165名正常受试者（11名男性，4名女性，平均年龄28.6岁，范围22至38岁）的双腕进行了研究。
拇指屈曲导致正中神经向桡侧横向移动（1.2±0.6毫米），而手指屈曲则使正中神经向尺侧横向移动，在示指和中指屈曲时最为明显（分别为3.2±0.9毫米和3.1±1.0毫米）。环指（2.0±0.8毫米）和小指（1.2±0.5毫米）屈曲时也有较小但仍具有统计学意义的移动。拇指或各手指屈曲均未改变正中神经横截面积（8.5±1.1平方毫米）。
拇指和各手指的主动屈曲，尤其是示指和中指，可使正中神经在腕管内产生显著的横向移动，但不改变神经的横截面积。这些发现对理解腕管综合征的发病机制及其治疗的重要性仍有待研究。
