van Oudenaarde E
University of Nijmegen, Department of Anatomy and Embryology, The Netherlands.
J Anat. 1991 Feb;174:221-7.
The abductor pollicis longus muscle was examined in dissections and histologically to study the insertions around the CMC I joint. The APL consists fundamentally of a superficial and a deep division, both terminating in one or more tendons. The deep division is proximally situated, it is covered by the extensor digitorum muscle and consists of several muscle bellies; it terminates in a central tendon. The fibres are short, obliquely attached to the tendon in a pennate manner and close together. After the passage through the extensor retinaculum the tendon separates into many branches. The superficial division is more distally situated, not covered by other muscles, lying superficial to the tendon of the deep part. The fibres are long, parallel to one another and form a thin layer. The tendon passes, together with the deep division, through the same compartment of the extensor retinaculum and inserts into MC I. If the muscle contracts, then the structures around the CMC I joint will be tensed by the deep division and MC I will be affected by the superficial division. It is to be expected that in the appropriate thumb movements the superficial part will show an isotonic contraction and the deep part, an isometric action. The superficial part, with long thin fibres, presumably has the least strength while the deep part, with its larger number of fibres, is the most powerful. The functional analysis gives the impression that the deep head will mainly support the trapezium as a platform upon which MC I moves. The superficial head will be active in moving MC I.
在解剖和组织学检查中对拇长展肌进行了研究，以探讨其在第一腕掌关节周围的附着情况。拇长展肌基本上由浅部和深部组成，两者均止于一条或多条肌腱。深部位于近端，被指伸肌覆盖，由几个肌腹组成，止于一条中央肌腱。其纤维短，以羽状方式斜向附着于肌腱且排列紧密。穿过伸肌支持带后，肌腱分成许多分支。浅部位于更远端，未被其他肌肉覆盖，位于深部肌腱的浅面。其纤维长，相互平行，形成一层薄肌层。浅部肌腱与深部肌腱一起穿过伸肌支持带的同一间隙，止于第一掌骨。如果肌肉收缩，那么第一腕掌关节周围的结构将被深部拉紧，而第一掌骨将受到浅部的影响。可以预期，在适当的拇指运动中，浅部将表现为等张收缩，而深部则表现为等长收缩。浅部纤维长而细，可能力量最小，而深部纤维数量较多，力量最强。功能分析给人的印象是，深部主要作为第一掌骨移动的平台来支撑大多角骨。浅部则在移动第一掌骨时起作用。
