Final answer:
Kyphosis is the medical term for humpback. It is an excessive posterior curvature of the thoracic region of the vertebral column and can develop due to osteoporosis.
Step-by-step explanation:
The medical term for humpback is kyphosis. Kyphosis is an excessive posterior curvature of the thoracic region of the vertebral column. It can develop when osteoporosis weakens and erodes the anterior portions of the upper thoracic vertebrae, causing their gradual collapse.