Final answer:
William, who sits extensively, is likely to show signs of an anterior pelvic tilt and lordosis due to the shift in his body's center of gravity, as well as possibly an increase in thoracic curvature, known as kyphosis, from prolonged poor posture.
Step-by-step explanation:
Individuals who sit for long periods, such as William, often develop a compensation pattern characterized by an anterior pelvic tilt. This condition is associated with lordosis, an excessive anterior curvature of the lumbar region. It arises due to a shift in the body's center of gravity to the front, leading to the pelvis tilting forward. This condition often occurs alongside an accumulation of weight in the abdominal area, common in obesity or pregnancy. Considering William's prolonged sitting, his posture would likely cause a similar shift in weight distribution, albeit due to muscular imbalances, leading to an anterior pelvic tilt. Another possible postural adaptation would be an increase in thoracic curvature, or kyphosis, which is an excessive posterior curvature of the thoracic region, commonly resulting from poor posture, such as slouching at a computer.