Background: Palmaris longus muscle is a degenerating superficial flexor muscle of forearm. Absence of palmaris
longus in different ethnic groups has been frequently encountered in clinical practice.
Aim & Objectives: Present study was done to determine the incidence of unilateral and bilateral absence of palmaris
longus and its association with gender and sides of the upper limb in western Indian population.
Methods & Material: The sample constituted 500 healthy subjects (250 males and 250 females) which were
examined clinically by standard technique. In subjects with an absence of palmaris longus tendon, three other clinical
tests were performed to confirm its absence.
Results: Overall absence of palmaris longus was observed in 91 subjects (18.2%) out of which 48 (9.6%) had
unilateral absence and 36 (7.2%) had bilateral absence. Frequency of unilateral (Males: 8.4%, Females: 10.8%) and
bilateral (Males: 5.2%, Females: 9.2%) agenesis was higher in females. In males, unilateral (8.4%) agenesis was
more common than bilateral (5.2%). In subjects with unilateral agenesis right side (5.2%) was more commonly
involved than left side (3.2%) in males whereas in females left side (7.2%) was more commonly involved than right
(3.6%). However in present study there was no statistical association observed between absence of palmaris longus
and gender or body sides in western Indian population.
Conclusion: Agenesis of palmaris longus, both forms unilateral and bilateral was fairly common in western Indian
population in both gender. Females had higher incidence of agenesis than males with unilateral agenesis more
common than bilateral.
Palmaris longus, Indian population, Tendon anomalies