electromyostimulation (ems) of astronauts in spaceflight (easymotion-2)

Conditions: Muscle Atrophy; Myotonia; Stiffness; Spine; Exercise Overtraining

Summary: 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

in a previous space analog study (60 days reactive jumps on a sledge during bed rest immobilisation, cologne, germany, 2015) on n=24 voluntary participants followed by an experiment on the international space station, iss (myotones 2015-2023) the investigators used non-invasive myoton technology (myoton device) to detect digital biomarkers (passive muscle tone and stiffness) on twelve (n=12) study participants together with clinical imaging (mri), muscle strength tests (dynamometry), and blood samples (biosamples) to study muscle properties and adaptation in microgravity following routine inflight exercise in iss astronauts. one of the myotones iss astronaut already tested a space-qualified easymotionskin suit (demo-tech experiment, german aerospace agency, deutsches zentrum fuer luft- und raumfahrt, dlr, 2022) that was used for about 20 minutes on top of the daily routine exercise protocol in order to optimize inflight training outcome by ems technology in spaceflight. preliminary results (n=1) showed feasibility of the novel ems technology in spaceflight and suggested improved muscle health parameters (increased tone and stiffness) found in some muscle from torso (lower back) and limbs compared to a non-ems mission crewmember. easymotion-2 is designed to replicate similar changes in inflight passive muscle parameters (resembling muscle health) in eight (n=8) more iss astronauts for robust statistical analyses and interpretation. pre and postflight baseline data collections with myoton technology (passive tone \[hz\] and stiffness \[n/m\]) serve as control for comparison. protocol and recruitment of healthy study participants (male or female astronauts) is under control by nasa via informed consent briefing standardized procedures.

Eligibility criteria:
inclusion criteria: astronauts with active flight medical exclusion criteria: * heart disease * liver disease * diabetes * thrombosis * extreme blood pressure * abdominal \& inguinal hernias (bulges) * strong neurological diseases * pregnancy * cancer

Keywords: skeletal muscle passive muscle stiffness muscle health electromyostimulation space flight countermeasure