Anautomatic parameter extraction methodforthe 7x50mStroke Efficiency Test

Wedeveloped anautomatic method toextract thepa- rameters ofthe7 x 50m Stroke Efficiency Test for swimming basedonawrist wornacceleration sensor device. Inthewrist acceleration signal wedetect char- acteristic swimevents suchaswallpush-offs, wall- strikes andstrokes. Basedonthis information wecom- putethedistance perstroke andtheswimming veloc- ity. Theupper error bounds ofourautomatic method are1.67% forthevelocity and1.33% forthetimeper stroke. Thevelocity measurement accuracy isofcom- parable order tothemanual accuracy. Theautomatic methodclearly outperforms themanualmeasurement forthetime perstroke extraction.