Which vertebrae are referred to as the "lower back"?

The lumbar vertebrae are referred to as the "lower back" because they are specifically located in the lower segment of the vertebral column, residing between the thoracic vertebrae above and the sacral vertebrae below. This region typically consists of five vertebrae labeled L1 through L5, which are larger and more robust than those in the cervical and thoracic regions. The primary function of the lumbar vertebrae is to provide support for the upper body, facilitate movement, and absorb shock, making them crucial for activities that involve bending, lifting, and twisting.

In addition, the lumbar region is where a significant amount of stress is placed during various physical activities, leading to a higher incidence of injuries in this area. This anatomical designation helps in understanding both the structure and the clinical significance of the lumbar region in athletic training and rehabilitation.