RESUMO
Monitoring compliance with exercise and motivating patients with lower back pain to perform prescribed exercise regimens are considerable tasks. The objective of this study was to develop and test a low-cost device that can be used by a patient at home to both record and provide real-time biofeedback of lumbar position in the midsagittal and frontal planes during exercises. Our device utilizes strain gages on a thin stainless steel beam to measure lumbar flexion-extension and an optical mouse sensor attached to the end of the blade to measure lateral bending. In comparison tests with a standard electrogoniometer, our device was shown to be accurate within 3 degrees in both the sagittal and frontal planes in healthy subjects. Furthermore, users were capable of reapplying the device themselves and obtaining measurements that were repeatable within 4 degrees in both planes. The capability of this simple device to accurately measure lumbar spine position in a nonlaboratory setting makes it well suited as a tool for providing feedback on exercise performance to both patients and clinicians.