Why is the non-dominant arm used in bone densitometry assessments?

• A. It is less prone to injury
• B. Reference values reflect non-dominant arm measurements
• C. It provides more accurate results
• D. It is preferable for alignment

Answer: (B)

The use of the non-dominant arm in bone densitometry assessments is primarily based on the fact that reference values for bone mineral density (BMD) measurements are typically established using non-dominant arm data. This ensures a consistent baseline for comparison across various populations and studies. The non-dominant arm generally exhibits lower muscle mass and usage than the dominant arm, which can lead to more accurately reflecting the bone density that is intrinsic to the bone structure itself, without the influence of increased physical activity and muscle loading that often characterize the dominant arm.

Establishing reference values from the non-dominant arm allows clinicians to make more applicable comparisons when evaluating a patient’s results against normative data. Hence, using the non-dominant arm enhances the reliability of bone density assessments and ensures that patients' results are interpreted within the correct context based on standardized measures.