Balancing the playing field: Collaborative gaming for physical training

Background: multiplayer video games promoting exercise-based rehabilitation may facilitate motor learning,by increasing motivation through social interaction. however,a major design challenge is to enable meaningful inter-subject interaction,whilst allowing for significant skill differences between players. we present a novel motor-training paradigm that allows real-time collaboration and performance enhancement,across a wide range of inter-subject skill mismatches,including disabled vs. able-bodied partnerships. methods: a virtual task consisting of a dynamic ball on a beam,is controlled at each end using independent digital force-sensing handgrips. interaction is mediated through simulated physical coupling and locally-redundant control. game performance was measured in 16 healthy-healthy and 16 patient-expert dyads,where patients were hemiparetic stroke survivors using their impaired arm. dual-player was compared to single-player performance,in terms of score,target tracking,stability,effort and smoothness; and questionnaires probing user-experience and engagement. results: performance of less-able subjects (as ranked from single-player ability) was enhanced by dual-player mode,by an amount proportionate to the partnership's mismatch. the more abled partners' performances decreased by a similar amount. such zero-sum interactions were observed for both healthy-healthy and patient-expert interactions. dual-player was preferred by the majority of players independent of baseline ability and subject group; healthy subjects also felt more challenged,and patients more skilled. conclusion: this is the first demonstration of implicit skill balancing in a truly collaborative virtual training task leading to heightened engagement,across both healthy subjects and stroke patients. © 2017 the author(s).