title: Indirect monitoring and analysis of truncal stress over extended time periods.
abstract: Low back pain is a common ailment encountered in clinical practice, yet there has hitherto been no completely satisfactory method for the measurement of truncal stress, which is a major factor in low back pain. Truncal stress has been difficult to record during the course of a working day because subjects were constrained by trailing cables attached to the monitoring equipment. We have used a pressure sensitive transmitter (radio pill) to record intra-abdominal pressure, which has been shown previously to be an indirect measure of truncal stress. The system makes possible multichannel recordings on magnetic tape throughout the working day by using a portable, battery powered recorder strapped to the subject's waist. A novel ferrite rod contributes materially to minimizing artefacts due to signal loss. The recorded data are replayed, at 60 times real time, into a microcomputer programmed to analyse this data.
mesh_terms: D000005:Abdomen; D001416:Back Pain / Q000503:physiopathology; D006801:Humans; D008838:Microcomputers; D008991:Monitoring, Physiologic; D011312:Pressure; D011846:Radio Waves; D013314:Stress, Mechanical; D013686:Telemetry; D013997:Time Factors