Most standard textbooks of hand surgery quote the prevalence of absence of palmaris longus at around 15%. However, this figure varies considerably in reports from different ethnic groups. We studied 329 Chinese men and women and found palmaris longus to be absent unilaterally in 3.3%, and bilaterally in 1.2%, with an overall prevalence of absence of 4.6%. There was no significant difference in its absence with regard to the body side or the sex. Our literature review revealed a low prevalence of absence in Asian, Black and Native American populations and a much higher prevalence of absence in Caucasian populations. It is clear that a standard prevalence of absence of the palmaris longus cannot be applied to all populations.

The palmaris longus tendon is the most frequently harvested tendon for reconstructive plastic and hand surgical procedures. A question patients often ask is whether loss of the palmaris longus will result in any functional deficit. In order to answer this question, the presence or absence of the palmaris longus muscle was clinically determined in 418 normal Asian subjects. All subjects also had their grip and pinch strengths measured. No statistically significant difference was seen in the grip or pinch strength measurements between subjects who had a palmaris longus tendon and those who did not. This study demonstrates that absence of the palmaris longus is not associated with a decrease of grip or pinch strength.