Measurement of the range and coupled movements observed in the lumbar spine.

The aim of this study was to set up a data base, using the Polhemus Navigation Sciences 3Space Isotrak system, of the range and coupled movements expected to be seen in the lumbar spine of people not experiencing spinal problems. Measurements were taken from groups of volunteers who had not previously experienced any form of serious back pain and who were not suffering from any pathology known to affect the spine. The 'normal' group was split into sections determined by age an dsex. Age was split into five categories, those aged 20-29 years, 30-39 years, 40-49 years, 50-59 years and 60-69 years. Range of motion was seen to be affected by both the age and sex of subjects. Lateral bend and axial rotation, flexion and lateral bend and flexion and axial rotation were all strongly coupled. The younger age groups tested exhibited a greater degree of coupled movement than the older groups.