Evaluation of Relationship Between Prevalence of Palmaris Longus Muscle and Handedness in Turkish Population

Palmaris longus (PL) is a fusiform muscle with a short belly and a long tendon that crosses superficially over flexor retinaculum. It flexes wrist and tenses palmar aponeurosis. The absence of PL prevalence varies from 0.6 % to 63.91 % in the literature. The existence of PL on the right hand is more common compared to the left hand. Thus, we aimed to determine the prevalence of PL in the Turkish population and the relation of PL absence with sex and handedness in this study. We evaluated 1050 students of Sakarya University between ages 18-28 who participated in the study (525 males, 525 females). After completing a questionnaire including handedness, the volunteers were examined on both hands using some standard tests to find out PL absences. Pearson chi-square and Fischer's exact tests were used for statistics in SPSS 22 software. It was determined that 937 subjects were right-handed (89.2 %), 70 subjects were left-handed (6.6 %) and 43 subjects were ambidextrous (4.1 %). The presence of bilateral PL was found in 653 subjects, while the absence of bilateral PL was defined in 186 subjects. The absence of PL on right and left hand was detected respectively on 108 (10.3 %) and 103 (9.8 %) subjects. Left-handedness was more common in males (7.2 %) than females (6 %). PL was absent in 397 (37.8 %) subjects unilaterally and bilaterally. The study showed that our population has similar prevalence of PL absence with literature. Moreover, there was no correlation statistically between the absence of PL and sex or handedness.