Spinal flexibility and individual factors that influence it.

We conducted an investigation to examine the spinal flexibility of a large, adult population and to study the effects of other individual physical characteristics on spinal range of motion. The study group consisted of 3,020 blue collar employees (2,350 men and 670 women) who underwent a physical examination that included assessments of standing and sitting height, weight, shoulder flexibility, and spinal flexibility in the sagittal and frontal planes. Flexibility measures were correlated positively to one another; however, lumbosacral flexion measurements assessed by the modified Schober method correlated to the other flexibility measurements to a much lesser degree. Age, sex, and height affected ROM, as did obesity and the ratio of standing height to sitting height. The study findings indicate that spinal ROM covers a wide spectrum of values and is affected by many individual factors. Any attempts to determine what is normal, excessive, or diminished must take into account variations caused by age, sex, and other physical attributes.