Analysis of Skeletal Muscle Metrics as Predictors of Functional Task Performance: 2895

Performance Jeffrey W. Ryder, Roxanne E. Buxton, Elizabeth Redd, Melissa Scott-Pandorf, Kyle J. Hackney, James Fiedler, Robert J. Ploutz-Snyder, Jacob J. Bloomberg Lori L. Ploutz-Snyder, FACSM. Universities Space Research Association, Houston, TX, University of Houston, Houston, TX, Wyle Integrated Science and Engineering Group, Houston, TX, Syracuse University, Syracuse, NY, NASA Johnson Space Center, Houston, TX PURPOSE: The ability to predict task performance using physiological performance metrics is vital to ensure that astronauts can execute their jobs safely and effectively. This investigation used a weighted suit to evaluate task performance at various ratios of strength, power, and endurance to body weight. METHODS: Twenty subjects completed muscle performance tests and functional tasks representative of those that would be required of astronauts during planetary exploration (see table for specific tests/tasks). Subjects performed functional tasks while wearing a weighted suit with additional loads ranging from 0-120% of initial body weight. Performance metrics were time to completion for all tasks except hatch opening, which consisted of total work. Task performance metrics were plotted against muscle metrics normalized to “body weight” (subject weight + external load; BW) for each trial. Fractional polynomial regression was used to model the relationship between muscle and task performance. RESULTS: The R values for normalized muscle performance versus task performance are presented in the table below. Supine Seat Egress and Walk Object Pick Up and Carry Ladder Treadmill Hatch Opening