Anatomical Study on the Psoas Minor Muscle in Human Fetuses Estudio Anatómico del Músculo Psoas Menor en Fetos Humanos

SUMMARY: The anatomy of the psoas minor muscle in human beings has frequently been correlated with ethnic and racial characteristics. The present study had the aim of investigating the anatomy of the psoas minor, by observing its occurrence, di stal insertion points, relationship with the psoas major muscle and the relationship between its tendon and muscle portions. Twenty- two human fetuses were used (eleven of each gender), fixed in 10% formol solution that had been perfused through the umbilical arte ry. The psoas minor muscle was found in eight male fetuses: seven bilaterally and one unilaterally, in the right hemicorpus. Five femal e fetuses presented the psoas minor muscle: three bilaterally and two unilaterally, one in the right and one in the left hemicorpus. The muscle was independent, inconstant, with unilateral or bilateral presence, with distal insertions at different anatomical points, and its tendon portion was always longer than the belly of the muscle.