Researchers at Nationwide Children's Hospital have developed a system for measuring motion (speed or reach) or cognitive (focus or prioritization) variables using an interactive game as an interface. By evaluating these variables using performance on a game-based system, the electronic Whack-a-Mole reduces volitional variation in measured performance and provides a platform for testing the impact of motivational stimuli at the same time as tracking performance variables particularly valuable for benchmarking the severity of muscular dystrophy or other upper extremity mobility disorders.