Toward standards for posture. Postural characteristics of the lower back system in normal and pathologic conditions.

On theoretic grounds it can be assumed that aberrations of posture may play a role in the generation of low-back pain by creating concentrations of stress. However, this assumption remains speculative because of the absence of criteria for normal posture. This study considers some of these criteria, especially as they are related to the lumbar spine and pelvis. The relations between the angle of declivity of the sacrum and radius and inclination of the lordotic curvature of the lumbar spine show good correlation. Mean values of postural parameters in the group of spondylolysis patients differ significantly from those in the group of healthy volunteers.