Smartphone Accelerometers (IMAGE) PLOS Caption Rating of video recordings. Time per contraction phase was annotated in milliseconds using a 2.5x magnification of the weight stack. Credit Claudio Viecelli, vclaudio@ethz.ch, mobile +41 79 238 97 08 Usage Restrictions CC BY 4.0--Redistribution permitted with credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.