Cobb T K, An K N, Cooney W P, Berger R A
Department of Orthopedics, Mayo Clinic, Rochester, Minnesota.
J Hand Surg Br. 1994 Aug;19(4):434-8. doi: 10.1016/0266-7681(94)90206-2.
Carpal tunnel syndrome is one of the many so-called cumulative trauma disorders thought by some to be related to the performance of repetitive tasks in the work-place. The cause of this disorder is unknown. We have observed lumbrical muscle incursion into the carpal tunnel during finger flexion. This study was conducted to determine the amount of this incursion in normal wrists. Five cadaver upper limbs were analyzed radiographically with radiopaque markers on the flexor retinaculum and the lumbrical muscle origins in four finger positions: full extension, 50% flexion, 75% flexion, and 100% finger flexion. The lumbrical muscle origins were an average of 7.8 mm distal to the carpal tunnel in full finger extension. They moved an average of 14 mm into the carpal tunnel with 50% finger flexion, 25.5 mm with 75% flexion, and 30 mm with 100% flexion. Abnormal lumbrical muscles have been cited as a possible cause of carpal tunnel syndrome. These findings suggest that lumbrical muscle incursion during finger flexion is a normal occurrence and is a possible cause of work-related carpal tunnel syndrome.
腕管综合征是众多所谓的累积性创伤疾病之一，有些人认为它与工作场所中重复性任务的执行有关。这种疾病的病因尚不清楚。我们观察到在手指屈曲时，蚓状肌会侵入腕管。本研究旨在确定正常手腕中这种侵入的程度。对五具尸体的上肢进行了放射学分析，在屈肌支持带和四个手指位置（完全伸展、50%屈曲、75%屈曲和100%手指屈曲）的蚓状肌起点处放置了不透射线的标记物。在手指完全伸展时，蚓状肌起点平均位于腕管远端7.8毫米处。随着手指50%屈曲，它们平均向腕管内移动14毫米；75%屈曲时移动25.5毫米；100%屈曲时移动30毫米。异常的蚓状肌被认为是腕管综合征的一个可能原因。这些发现表明，手指屈曲时蚓状肌的侵入是正常现象，并且可能是与工作相关的腕管综合征的一个原因。
