chapter  16
17 Pages

Measuring Physical Activity with Body-Worn Accelerometers

WithAlex V. Rowlands

Physical behaviors across the 24 hour day can be categorized as sleep, sedentary behavior and physical activity. Movement, or lack of movement, due to these physical behaviors can be captured using accelerometry-based activity monitors worn 24 hours a day. Accelerometers are small wearable motion sensors that measure the accelerations of the body part they are attached to and provide time-stamped data, facilitating assessment of temporal patterns of physical behaviors. Historically, studies have focused on the importance of physical activity, particularly moderate- to-vigorous physical activity, for children’s health. Probably the most widely used accelerometer in the physical activity research literature to date is the ActiGraph. Accelerometers that store high-resolution raw accelerations for multiple days were not commercially available until after 2010.