Which movement describes a rounding of the lower back?

The movement that describes a rounding of the lower back is a posterior tilt. This action involves the pelvis tipping backward, which causes a flattening or rounding of the lumbar spine. When the pelvis tilts posteriorly, it results in a decrease in the normal curvature of the lower back, making it appear rounded.

This is often seen in exercises or movements that emphasize hip flexion, where the lower back is not maintained in its neutral position. A posterior pelvic tilt is typically used in various fitness contexts, such as during core exercises or stretches aimed at improving flexibility in the lumbar region.

In contrast, a neutral spine refers to maintaining the natural curves of the spine without excessive rounding or arching. The prone position involves lying face down and does not specifically relate to the curvature of the lower back. An anterior tilt, on the other hand, involves the pelvis tilting forward, which increases the lumbar curvature rather than rounding it.