Anthropometric Study of Humeral Torsion Angle in South-South and South-East Nigeria

Aims: Torsion is defined as a state of longitudinal twisting or spiraling of shaft of a long bone and can be measured as the difference between joint axis of proximal and distal ends of the bones. Angle of humeral torsion entails the reorientation of head of humerus bone relative to its shaft, the head being directed medially rather than caudally. Torsion occurs between proximal and distal extremities of the humerus, with humeral head facing postero-medially in anatomical position. Humeral torsion has an impact on shoulder function, movement, and the likelihood of injury. Irregular torsion can result in limited range of motion, discomfort, and diminished athletic performance. Gaining insight into torsion patterns can enhance rehabilitation, surgical approaches, and athletic training. Studies may also contribute to advancements in prosthetic development, surgical methods, and safety equipment. Precise evaluation of humeral torsion is vital for effective treatment and preventing injuries. The anthropometric study of angle of humeral torsion aims to understand the variation in the angle of humeral torsion among individuals and populations; however, this study focused on South-South and South East, Nigeria. The results concluded that there was no significant difference in mean values of angle of humeral torsion on right and left side bones.

Study Design: Descriptive and cross-sectional study.

Place and Duration of Study: University of Port Harcourt, South-South, Nigeria.

Methodology: Two hundred humeri belonging to skeletons of unknown age, sex, and stature were collected from Medical Colleges of various Nigeria universities in South-South and South East, Nigeria. The torsion angles of these bones were then measured with the goniometer. Out of 200 humeri, 112 were of right side and 88 were of left side.

Results: The result of the study showed the right torsion (φ) 73.87± 5.67 and left torsion (φ) 73.78±5.48.

Conclusion: This study presents new evidence indicating that the humeral torsion angle is symmetrical on both sides, showing no significant variation between the right and left humeri. This findings adds to the current body of knowledge by creating a normative reference range for humeral torsion, which can assist in the diagnosis and management of shoulder injuries and disorders.