Low-back pain has become an overwhelming prevalent problem causing activity limitation in the lives of many Americans and an unnecessary burden on physicians. The etiology of most cases remains unknown and current treatments remain ineffective in many cases. Recent research suggests that low-back pain is heavily influenced by repeated daily movements that stress specific areas of the spine. Better monitoring solutions are needed to reveal and correct these repeated movements, but current methods are unfit for daily use outside of laboratory environment. The Spinal Motion Sensor takes advantage of current inertial motion technologies and sensor fusion algorithms that can measure orientation with higher accuracy and lower power than ever before. The central motion sensor chip, the InvenSense ICM-20948, uses a gyroscope, accelerometer, magnetometer, and digital motion processor to collect nine axes of data and calculate a final quaternion orientation vector. Multiple sensors can be placed on the spine to monitor the orientation at each location. The sensor is Bluetooth-enabled, allowing for orientation data to be transmitted back to any mobile device. If a mobile device is not present, the data can be saved locally to flash memory and collected later. The sensor was tested for long-term drift to ensure that the sensor does not drift throughout the length of a data collection session. Power consumption testing of the sensor in different configurations revealed a battery life of approximately 20 hours. Patients will be able to wear and use their sensor for a full day of activity, revealing any high-risk movements that may be causing low-back pain.