Background: The palmaris longus is a degenerating weak flexor muscle in the anterior of the forearm, it is extremely variable both in number and form, the most frequent variation is complete absence of the muscle. The aim of the study: study the Prevalence of absence of palmaris longus in nineteen and nine age groups. Subjects: The study included 800 persons (boys and girls) in 2 age groups of (Ninteen and nine ages), 400 in each group (200 boys and 200girls). In subjects with an absent palmaris longus, four tests (Schaeffer’s, Thompson, Pushpakumar and Mishra tests) were performed to confirm the absence.
Results: The overall prevalence of bilateral, right, left, and total absence of the palmaris longus were 83%, 7%, 5.5% and 4.5%, in age nineteen respectively and 80.75 %, 8%, 6.5% and 4.75% in nine age group respectively. There was significant difference between Prevalence of palmaris longus on the right side between the two groups; otherwise there was no significant difference in its absence regarding side or gender in the two different groups. (P > 0.05).
Conclusions: presence of the palmaris longus muscle tendon in Sohag population was considerably higher than the absence. The overall prevalence of bilateral, right, left and total absence of the palmaris longus was not significantly different between males and females. The overall prevalence of bilateral, left and total absence of the palmaris longus was not significantly different between nineteen and nine age groups.