Lumbar spine

The lumbar spine is the lower section of your backbone, sitting between the ribcage and the pelvis. It's made of large, sturdy vertebrae that carry most of your upper body's weight and allow you to bend and twist. Because of this role, the bone here is largely trabecular — a spongy, honeycomb-like structure that turns over faster than the denser cortical bone found in places like the hip.

This is one of the three standard sites measured on a DEXA scan, along with the femoral neck and total hip. Doctors watch it closely because trabecular bone tends to show changes in bone density earlier than other sites, making it useful for catching early loss. However, after about age 60, things like spinal arthritis, calcium deposits in the aorta, or old compression fractures can add extra mineral to the scan area and make the lumbar spine reading look falsely high — which is why your hip results matter too.

Diagnosis of osteoporosis or osteopenia is based on the lowest valid T-score among the sites measured, not just the spine alone. If your lumbar spine and hip numbers disagree, that's normal and expected, and your doctor can help interpret what it means for you. Keeping this part of your spine strong and well-supported also matters for posture, balance, and avoiding the kind of compression fractures that can lead to height loss over time.