When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. When you use a compass app on your smartphone, it somehow knows which direction the phone is ...

Objective Self-reports of physical activity (PA) have been the mainstay of measurement in most non-communicable disease (NCD) surveillance systems. To these, other measures are added to summate to a ...

We barely notice them, but they're one of the most important features buried in the everyday smartphone experience. Accelerometers are devices that can measure acceleration (the rate of change in ...