This study compared the MilestonePod (MSP) wireless running sensor to a fully instrumented treadmill (FIT) in measuring average vertical loading rate (AVLR), ground contact time (GCT), cadence, and stride length. MSP data from treadmill was also compared to MSP data during outdoor overground running. The MSP accurately measured GCT, cadence, and stride length during treadmill running compared to the FIT but failed to provide accurate AVLR data