A posture monitoring system using accelerometers

A new method of monitoring spinal posture in the sagittal plane is presented. Posture is measured during activities of daily living utilizing accelerometer inclinations of six points along a subject´s spine. The over sampled, low frequency filtered data can be monitored and collected over extended periods (up to four weeks) utilizing the inexpensive, low-power, portable data logger developed in the course of this research. The data logger utilizes 7 processors to collect and store data onto an MS-DOS formatted CompactFlash card for later analysis. Two trials were done: regimented postures across a one hour period and unregimented activities during a five hour period. Data was then visualized graphically and compared to noted postures and activities. The system was designed to be accurate to within ±0.5°. Measured precision was found to be within ±0.39°. This system will be useful for monitoring changes in back curvature resulting from surgery or treatment.