Which of the following sites is considered a central site of the skeleton?

• A. Forearm
• B. Fingers
• C. Lumbar spine
• D. Metacarpals

Answer: (C)

The lumbar spine is considered a central site of the skeleton due to its role in providing stability and support for the body, as well as its significance in assessing bone density for diagnosing conditions like osteoporosis. The lumbar region of the spine contains a higher concentration of trabecular bone, which is more metabolically active and responsive to changes in calcium metabolism and loading. Bone densitometry assessments often focus on this area because it reflects the overall bone health of an individual and is a common site for osteoporotic fractures.

In contrast, the other options—forearm, fingers, and metacarpals—are more peripheral skeletal sites. Although these areas can still provide useful information about bone density, they do not offer the same comprehensive analysis of central bone health as the lumbar spine. Therefore, the lumbar spine is the key central site used in clinical settings for monitoring and evaluating skeletal health.