Final answer:
Humpback, medically termed as kyphosis, is a postural abnormality with excessive posterior curvature of the thoracic spine, often due to osteoporosis. It can significantly impact posture and is distinguished among other spinal conditions such as lordosis and scoliosis.
Step-by-step explanation:
Postural Abnormality Known as Humpback
The postural abnormality commonly referred to as humpback is also known as kyphosis. This condition involves an excessive posterior curvature of the thoracic region of the vertebral column. Kyphosis can emerge as a consequence of osteoporosis, a condition that leads to the weakening and erosion of the anterior aspects of the upper thoracic vertebrae, causing them to collapse over time. This type of spinal deformation can notably affect posture and may develop into a more pronounced condition colloquially called dowager's hump, particularly in elderly women due to the prevalence of osteoporosis in this demographic.
Besides kyphosis, there are other abnormal curvatures of the spine such as lordosis, an excessive anterior curvature of the lumbar region, and scoliosis, an abnormal lateral curvature. These spinal disorders affect posture and can have various causes, including developmental anomalies, pathological changes, or physical conditions such as obesity or pregnancy.