Investigating arm symmetry in swimming using inertial sensors

This research used an sacrum mounted self developed inertial sensor, which provides triaxial accelerometers and gyroscopes, RF capability and 2GB on-board memory in a waterproof casing to investigate the arm symmetry in freestyle swimming. The recorded acceleration data was filtered using a high-pass Hamming windowed FIR filter to remove the sensor orientation from the wanted signal. The signal was then analyzed using a zero-crossing detection algorithm to find the individual stroke rates (SR) and the differences between left and right arm stroke durations (asymmetry).