Our goal was to develop an inexpensive and accurate gait tracking device that could be easily implemented in the field by researchers and clinicians. Measures of step length (SL) and step width (SW) variability are critical because they are linked to falls. However, these measures cannot be captured with current devices for field research. The simplest and most widely available approach was to use the Smartphone camera (attached at the waist) to capture SL and SW. Using a camera may appear impractical due to the following challenges: calibration of a moving camera, obstruction of the field of view, trunk motion, etc. We have addressed these challenges in the development of a new device, the SmartGait.