Three-dimensional kinematics and trunk muscle myoelectric activity in the young lumbar spine: a database.

Abstract

To document the three-dimensional (3D) kinematics of the lumbar spine and the myoelectric activity of trunk muscles throughout the range of motion in selected tasks performed by healthy subjects. A survey of a single population. A research laboratory in a university setting. Twenty-four men and women, university-age, with no history of chronic lower back pain volunteered for this study. The selected tasks consisted of lateral bend and axial twists to the right and left plus four different flexion-extension tasks that varied a hand-held weight (10kg and 0kg), and flexion-extension velocity (free-paced and 20 degrees/sec). 3D lumbar spine kinematics and normalized, linear enveloped electromyogram (EMG) of trunk muscles. The motion time histories were illustrated graphically. Consistent spinal kinematics and EMG activation patterns during each task across subjects were seen. Peak displacement values between tasks, using one-way analysis of variance, showed no significant difference. A database of healthy spine kinematics and normalized linear enveloped trunk muscle activation patterns were developed for future comparison of elderly and pathological subjects.