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Updated: Aug 6, 2026
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Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact
Published on: February 10, 2015
Os acromiale: population differences and their etiological significance
D T Case1, S E Burnett, T Nielsen
1Department of Sociology and Anthropology, North Carolina State University, Raleigh, 27695-8107, USA. dtcase@server.sasw.ncsu.edu
Summary
Os acromiale, a common skeletal defect, appears more frequent in South Africans than medieval Danes, suggesting a genetic link. However, a left-side bias hints at mechanical stress also playing a role in its development.
Area of Science:
- Orthopedics
- Anthropology
- Human Anatomy
Background:
- Os acromiale is a frequent accessory bone defect caused by the failure of the acromial apophysis to fuse with the scapula.
- Its etiology remains unclear, with competing hypotheses suggesting genetic factors or mechanical stress during development.
Purpose of the Study:
- To investigate the etiology of os acromiale by comparing its prevalence in South African and medieval Danish skeletal samples.
- To evaluate the support for genetic versus mechanical stress hypotheses for os acromiale development.
Main Methods:
- Comparative analysis of os acromiale frequencies in a South African cadaver sample (n=494) and a medieval Danish archaeological sample (n=532).
- Examination of left-side bias and potential sex/age influences.
- Stratification of the Danish sample by socioeconomic status to assess mechanical stress impact.
Main Results:
- South African sample showed a significantly higher os acromiale frequency (18.2%) compared to the medieval Danish sample (7.7%).
- A significant left-side bias (72%) was observed in the South African sample.
- No significant frequency difference was found between high and low socioeconomic status groups in the Danish sample.
Conclusions:
- Findings support a genetic predisposition for os acromiale, potentially influenced by mechanical stress.
- A combined genetic and mechanical etiology is proposed for os acromiale development.
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