Kyphosis is the term given to an exaggerated dorsal curve of the thoracic region of the spine. This can come about, for instance, through sitting curled over a desk for long periods of time, or by constantly bending down towards small children or work surfaces. Kyphosis not only causes discomfort in the neck and upper back but can restrict the functioning of the lungs and other internal organs. The curvature of the upper back and chest can also put pressure on the nerves of the upper arms and contribute to problems such as RSI.
If the Alexander Technique is used early enough, it is often possible to prevent kyphosis from developing and if learned later on in the condition's development, it can help reduce further degeneration.
This great sculpture called 'The Scholar' by Tapfuma Gusta, which I photographed in South Africa, clearly shows the upper spine and body curving forwards and down - presumably towards his desk after years of writing and reading many many books.