Pedometer Evaluation Project


Pedometers have become ubiquitous devices for helping motivate people to be more active by counting their daily steps. However, pedometer accuracy varies widely depending on the body position at which it is worn, the signal processing algorithm used to count steps, and individual differences in human gait. This project recorded a large data set of raw accelerometer data and marked the time occurrences of all steps so that pedometer algorithms could be evaluated objectively against a gold standard.


The below image shows raw (x,y,z) accelerometer data for 3 different devices worn on the wrist, hip and ankle (top to bottom), along with a screenshot of the synchronized video recording. Click the image to watch a video snippet.

Method used to record data and ground truth Example data (click to watch video snippet)

A group of 30 subjects were recorded walking a cumulative total of over 60,000 steps, including portions in a regular gait (walking a path), semi-regular gait (walking around a building), and irregular gait (walking around a room). The data set and ground truth can be downloaded here (275 MB). In a ground truth file, the number indicates the line index in the data file at which a step occurred. Videos and sync files can be downloaded here (11 GB).

Papers about this project:

Pedometer Evaluation Page / Clemson /