A novel method for synchronizing motion capture with other data sources for millisecond-level precision

Synchronization of multiple data collection systems is necessary for accurate temporal alignment of data, and is particularly important when considering rapid movements which occur in less than one second. This paper describes a novel method for synchronizing multiple data collection instruments including load cells and a motion capture system, using a common analog signal. An application of the synchronization method is demonstrated using biomechanical data collected during a rapid reach-to-grasp reaction, where data from motion capture and load cells are collected. Results are provided to validate and demonstrate the accuracy of the synchronization of motion capture with other data collection systems. During the reach-to-grasp trials, delays between the data collection systems ranged from 4 ms to 235 ms. The large range and variability in delay times between trials highlights the need for synchronization on a continual basis, rather than application of an average or constant value to correct for time delays between systems.