Determination of Angles of Torsion and Retroversion of the Humerus of Male and Female Skeleton Specimens in Uganda

Several studies have been done on the measurement of angles of humeral torsion and retroversion in different parts of the world but no records to show for any done in Uganda. In this study we aimed to determine the angles of humeral torsion and retroversion of adult skeletons in Uganda and to compare the observation in this study with the findings of other workers in different races and discussing our finding in light of literatures. Measurement of the angles of humeral torsion and retroversion of adult skeletons was done at the Galloway Osteological Collection (Museum) Mulago, Uganda, to determine the angles of torsion and retroversion of the humerus in male and female specimen. The true value of the angle of the humeral torsion is obtained by subtracting 90° from the obtuse angle, while the angle of retroversion is a complementary angle of torsion. This study finds the average angle of humeral torsion to be 56.61±9.57 and retroversion to be 33.39±9.52°. The angle of torsion of the right and left humeri, been 54.67±9.62 and 58.55±9.52 respectively, while retroversion angle is 35.33±9.62 on the right and 31.45±9.52 on the left. Therefore there is a greater torsion angle on left side than on the right side and retroversion is less on the left side than on the right side. There was a significant difference between the mean value of the torsion angle of the right and left humeri of the same skeleton, therefore confirming that there is a difference between the angle of torsion and retroversion on the two sides (right and left) in a particular person.