Research Outcome Monitoring tailors the activities used for the evaluation and validation of various sensor technologies to the specific needs of wearable activity sensor industry. This provides high value to industry partners through evidence-based results about the quality of activity tracker accuracy and can offer solutions for improvements in accuracy of such devices along with the development of the algorithms to interpret and apply the data the sensors produce. Research on the human interface will develop algorithms to translate sensor signals into meaningful and biologically valid output for clinical applications and to determine the functionality and wearability of sensor designs. User testing will determine how the brain, muscles, bones, and supporting structures and systems are impacted by different perturbations. Evaluation of prototype sensors and comparison to commercial benchmarks to establish data on effectiveness and usability. Iterate through Clusters 1-3 for platform optimization in terms of non-invasiveness and functionality.