Many with Scheuermann's disease often have an excessive lordotic curve in the lumbar spine; this is the body's natural way to compensate for the kyphotic curve above. Many with Scheuermann's disease have very large lung capacities and males often have broad, barrel chests.
The text describes how Scheuermann's disease affects the spinal curvature, particularly the lumbar spine, and its relationship to the thoracic spine. It also mentions that individuals with this condition may have larger lung capacities and males tend to have broader chests.