Validity and Reliability of Using a Belt-Worn Accelerometer on the Lower Back to Monitor Physical Activity

This study evaluated the validity and reliability of physical activity measurements collected using a belt-mounted accelerometer worn at the lumbar spine. The study consisted of two parts, with 10 healthy participants in each part. In part 1, physical activity measurements collected from a belt-mounted accelerometer were compared with that from a skin-mounted accelerometer during controlled exercises and free-living activities, with both accelerometers worn simultaneously at the same anatomical location. In part 2 physical activity measurements in controlled exercises were compared between two different days, with either the belt-mounted accelerometer or skin-mounted accelerometer worn singularly. The results demonstrated no significant difference in physical activity measurements between either mounting method, or between the two testing days during controlled activities. These results indicate that the belt-mounting method is valid and has good day-to-day reliability and can be used in studies requiring long-term data collection to assess the impact of physical activity-related rehabilitation and low back pain.