Freestyle Swimming Analysis of Symmetry and Velocities using a MEMS based IMU: Introducing a Symmetry Score

Andy Stamm, Andy Stamm, Igor Shlyonsky


MEMS sensors (IMU’s) are widely available nowadays and tend to be used more often in sports monitoring. Especially in swimming these sensors have seen rapid development in the past years. These sensors have very good measurement capabilities today, but the automatic analysis of the gathered data has not yet been implemented. Our objective is to develop and validate an automatic analysis which can provide the swimmers/coaches with nearly immediate feedback on a smartphone/tablet. Ten swimmers ranging from novice to elite have been participating in this study performing freestyle in either 25m or 50m pools. All trials were recorded with a 3-axis accelerometer. The symmetry parameters have been extracted from the recorded data after these were high-pass filtered to remove the gravity from the signal and a zero crossing detection algorithm was applied. The results showed a very strong relation to results obtained by other researchers.


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