Anatomical Variations of the Palmaris Longus Muscle

Background and Aims: The palmaris longus muscle (PLM) attaches to the common flexor tendon and inserts distally into the palmar aponeurosis. This study was performed to identify surface anatomical variations in the palmaris longus muscle among Omdurman Islamic University students. Methods: A cross-sectional study was conducted on Omdurman Islamic University students (Medical and Health Services Administration, Prof. Abd Ala al Aledressi Health Center). The sample size was determined by using 12,000 first-year university students in 2020/2021 with a confidence interval of 95% and a margin of error of 3.5%, and it was calculated to be 737 subjects (520 males and 217 females). Results: The overall frequency of palmaris longus muscle absence in both males and females, either unilaterally or bilaterally, was 12.6%. Of the overall study subjects (N = 737), palmaris longus muscle was detected in 644 (87.4%) bilateral cases, 24 (3.3%) agenesis in the right case, 32 (4.3%) agenesis in the left case, and 37 (5%) bilateral absent cases. Females are more likely than males to exhibit bilateral palmaris longus muscle agenesis, especially on the left side (p<.05). The relationship between handedness and the prevalence of missing palmaris longus is statistically insignificant (p > 0.05). Conclusions: It was concluded that 12.6% of Omdurman Islamic University students missing the palmaris longus muscle. Females exhibit a higher frequency of absence.