WrestleBrainia: Arm-wrestling Using Muscle Electrical Activity Rather than Strength
WrestleBrainia 3000 (WB3000) is an engaging two-player game that utilizes electrical signals from muscles to allow users of all ages to play an arm-wrestling game where neuromuscular signal strength, instead of physical strength, determines the winner. Participants get direct visual feedback about their muscle firing patterns and learn basic concepts about the nervous system and neural engineering. WB3000 was developed by student researchers in a design competition judged by industry representatives at the Center for Sensorimotor Neural Engineering (CSNE), an NSF-funded Engineering Research Center (ERC) with headquarters at the University of Washington.
More than 1000 people, from elementary school children to elderly adults, played WB3000 at several large events in the first eight weeks after it debuted in February 2013. WB3000, developed by CSNE students, has helped showcase the talents of CSNE students and raise public awareness of the potential of neural engineering to create fun games, transform the human-computer interface, and provide life-changing assistance to people suffering the devastating effects of stroke, Parkinson’s disease, and spinal cord injury. We expect that thousands more players will try the game in the coming year.
WB3000 works by using surface electrodes to detect electrical signals in firing muscles (EMG). Signals from each player are recorded, amplified, and measured against a resting state baseline. Amplified and processed signals between the two players are compared to determine whose signal is stronger and thus which way to move the fuzzy pink wrestling arms. Almost everyone who plays tries harder than they thought possible and wears a huge grin when they’re done. Electrodes can be placed on any muscle group, so participants can be creative in what contests they perform. Smile contests have become a popular variation on the traditional arm-electrode-driven wrestling match.
Since EMG signals depend less on total muscle size than on skin conductance, muscle fiber recruitment, and effort over baseline, smaller and weaker players can compete with larger, stronger players. This means that kids can beat grownups, non-athletes can beat jocks, and anyone who tries hard has a decent chance to win. There are some tricks about contracting and relaxing muscles that can give you an advantage, but you’ll have to play to figure them out! WB3000 seems to tap into everyone’s grade-school fantasy of being stronger than bigger classmates, siblings, or adults.