Researchers found smartphones were as effective as pedometers and accelerometers in monitoring number of steps. Study subjects walked on a treadmill wearing a pedometer, accelerometer and smartphone. The study patients wore all of the devices at the same time. The patients performed four walks with the treadmill set at 3 mph — two walks of 500 steps and two of 1,500 steps. At the end of each walk, the researchers compared the reading on each device to the manual step count. Although pedometers achieve the same purpose, they have not been widely adopted, noted the researchers, and because of the widespread use of smartphones, the latter device may be a better choice.– Published Feb. 10 in JAMA.