Psoas minor - a cadaveric study

Abstract

Introduction: The psoas muscle group is part of the posterior abdominal wall and is comprised of long muscles - major, minor and tertius. Out of those, only the psoas major muscle is an obligatory muscle present in all individuals. The psoas minor originates as vertical fascicles inserted on the bod­ies of the last thoracic and first lumbar vertebrae inserting into the iliopectineal eminence. The mus­cle`s actions are bending of the lumbar spine in a limited fashion. The aim of the study is to establish the frequency of the muscle in the Bulgarian population. Materials and Methods: This study was carried out in the Department of Anatomy and Cell Biology, Medical University - Varna `Prof. Dr. Paraskev Stoyanov`, Varna, Bulgaria, in November, 2017 on a total of 10 cadavers. The length, width and circumference of the muscle`s body were measured. The collected data was interpreted in a descriptive manner. Results: The psoas minor muscle was present in six out of ten cadavers (60%). Out of those six cadav­ers, the muscle was bilateral in three, left-side unilateral in one and right-side unilateral in two ca­davers. The average length of the muscle was 19.66cm (minimum 14.4cm - maximum 21.7cm), average width was 1.73cm (minimum 1.0cm - 3.2cm maximum) and average circumference was 3.48cm (min­imum 1.7cm - maximum 5.6cm). Male to female ratio of cadavers with a psoas minor muscle was 1:1. Conclusions: The frequency of the muscle`s variations considering its presence in the Bulgarian pop­ulation (60%) is higher when compared to its presence in the Indian population (36.67%), virtually identical to the Brazilian population (59%) and lower than that reported in United States of Ameri­ca (65.6%). The morphometric analyses between the different populations showed a shorter psoas mi­nor in the Bulgarian population.