Influence of spinal curvature on exercise capacity.

It is well recognized that scoliosis in excess of 65 degrees results in cardiorespiratory impairment. Lesser degrees of spinal curvature have been noted to have near normal respiratory function studies at rest. Because of the great cardiorespiratory reserve, decreases in function secondary to scoliosis may be masked in studies conducted at rest. To study this concept, an investigation of the work capacity of 38 adolescent children with varying degrees of adolescent idiopathic scoliosis was undertaken. The maximal oxygen capacity and endurance time was measured and compared with a group of normal controls. A significant negative correlation between percentile endurance time and degree of spinal curvature was found showing a reduction in endurance time with every 20 degrees increase in spinal curvature (p less than 0.006). The application of "the exercise capacity test" as an investigative tool for scoliosis was found to be practical, since endurance time is a reliable index of the cardio-pulmonary status.