Three-dimensional lumbar spinal kinematics: a study of range of movement in 100 healthy subjects aged 20 to 60+ years

The three-dimensional (3D) range of movement of the non-pathological lumbar spine was established using the Polhemus Navigation Sciences 3Space Isotrak system. One hundred subjects (50 male, 50 female) ranging in age from 20 to 77 yr and with no history of recent low back pain participated in the study. Each subject performed the gross movements of forward flexion, backward extension, side-flexion to the left and right and axial rotation to the left and right. All movements were carried out at the subject's own pace. The results indicated consistently greater flexibility in females than males throughout the age range. Differences in ranges of motion were recorded between younger and older age groups. The recorded ranges of motion showed a good level of agreement with X-ray data, indicating concurrent validity and reasonable similarity with previous 3D studies using electromagnetic goniometers. It would appear that the methods used in this study are capable of measuring the lumbar spinal range of motion routinely in the clinical environment