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

Objective. The three-dimensional (3D) range of movement of the non-patholog ical lumbar spine was established using the Polhemus Navigation Sciences 3S pace Isotrak system. Methods. One hundred subjects (50 male, 50 female) ranging in age from 20 t o 77 yr and with no history of recent low back pain participated in the stu dy. Each subject performed the gross movements of forward flexion, backward extension, side-flexion to the left and right and axial rotation to the le ft and right. All movements were carried out at the subject's own pace. Results. The results indicated consistently greater flexibility in females than males throughout the age range. Differences in ranges of motion were r ecorded between younger and older age groups. The recorded ranges of motion showed a good level of agreement with X-ray data, indicating concurrent va lidity and reasonable similarity with previous 3D studies using electromagn etic goniometers. Conclusions. It would appear that the methods used in this study are capabl e of measuring the lumbar spinal range of motion routinely in the clinical environment.