Gangata Hope
Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town City, South Africa.
Clin Anat. 2009 Mar;22(2):230-5. doi: 10.1002/ca.20751.
The presence of the palmaris longus muscle (PLM) is highly variable. Rates of absence vary from 0.6% in the Korean population to as high as 63.9% in the Turkish population. The tendon of PLM may be absent on one or both forearms, may have duplicated tendons on one forearm or may be laterally shifted to the extent that the tendon of the PLM lies superficial to that of flexor carpi radialis muscle. Among Black American populations, in which there is usually mixed ancestry, rates of absence are 3.5%. Only two studies have been performed on Black African populations: in Republic of Congo and Uganda, and each showed widely differing rates of absence of 3.0% and 14.6%, respectively. In this study, a total of 890 Black Zimbabwean subjects in Harare aged between 8 and 13 years, were examined for clinical surface anatomy anomalies of the tendon of PLM. The results showed that the tendon of the PLM was absent unilaterally in 0.9% of the population, and bilaterally absent in 0.6% with an overall rate of absence of 1.5%. Other variations noted were a laterally shifted PLM in 1.1% of subjects and duplicated tendons on one forearm, which was the least prevalent anomaly, in 0.2% of subjects. The author proposes a new technique to test the tendon of PLM, which combines resisted thumb abduction and resisted wrist flexion. The proposed technique capitalizes on the role of the PLM as an important abductor of the thumb.
掌长肌（PLM）的存在情况差异很大。缺失率从韩国人群中的0.6%到土耳其人群中高达63.9%不等。PLM的肌腱可能在一侧或双侧前臂缺失，可能在一侧前臂有重复的肌腱，或者可能向外移位，以至于PLM的肌腱位于桡侧腕屈肌肌腱的浅面。在通常有混合血统的美国黑人人群中，缺失率为3.5%。仅对非洲黑人人群进行过两项研究：在刚果共和国和乌干达，每项研究显示的缺失率差异很大，分别为3.0%和14.6%。在本研究中，对哈拉雷890名年龄在8至13岁之间的津巴布韦黑人受试者进行了PLM肌腱临床体表解剖异常检查。结果显示，PLM肌腱单侧缺失的人群占0.9%，双侧缺失的占0.6%，总体缺失率为1.5%。其他观察到的变异包括1.1%的受试者中PLM向外移位，以及0.2%的受试者中一侧前臂有重复肌腱，这是最不常见的异常情况。作者提出了一种测试PLM肌腱的新技术，该技术结合了抗阻拇指外展和抗阻腕关节屈曲。所提出的技术利用了PLM作为拇指重要外展肌的作用。
