Electromyostimulation (EMS) of Astronauts in Spaceflight (Easymotion-2)

This is a prospective spaceflight study involving an investigational non-risk device called the EasyMotionSkin for whole body electric muscle (myo) stimulation (WB-EMS) onboard the International Space Station (ISS). The purpose of this study is to show: * optimized exercise outcome with EMS in human spaceflight * demonstrate efficacy of EMS as alternative inflight exercise protocol * provide a time-saving and reliable EMS-assisted exercise protocol compliant to astronauts for later use in planetary habitats and future deep space exploration Eight (n=8) astronauts on long duration missions will take part in this study. This experiment uses the following hardware/software (HW \& SW): (A) EasymotionSkin suit (dry electrode muscle stimulation), B) non-invasive hand-held Myoton device (digitized passive muscle stiffness data collection). C) a customized Myoton body template suit (elastic yoga suit with customized anatomical reference labels to aid inflight Myoton data collection on dedicated perforated 2x2 cm small skin fields) at 5 different skin measurement points (MP), neck, back, shoulder, legs. Before and after flight the following tests will be done once: Myoton data collection, dynamometry strength test, magnetic resonance imaging (MRI) for baseline comparison. Researchers will compare data from a non EMS control group (non EMS Astronauts, retrospective) to see if changes of passive muscle stiffness is seen in EMS Astronauts before, during and after spaceflight