A metric for characterizing the arm nonuse workspacein poststroke individuals using a robot arm

Nathaniel S. Dennler, Stefanos Nikolaidis, Maja Mataric

Abstract: An overreliance on the less-affected limb for functional tasks at the expense of the paretic limb and in spite ofrecovered capacity is an often-observed phenomenon in survivors of hemispheric stroke. The differencebetween capacity for use and actual spontaneous use is referred to as arm nonuse. Obtaining an ecologicallyvalid evaluation of arm nonuse is challenging because it requires the observation of spontaneous arm choice fordifferent tasks, which can easily be influenced by instructions, presumed expectations, and awareness that oneis being tested. To better quantify arm nonuse, we developed the bimanual arm reaching test with a robot(BARTR) for quantitatively assessing arm nonuse in chronic stroke survivors. The BARTR is an instrument thatuses a robot arm as a means of remote and unbiased data collection of nuanced spatial data for clinical evalu-ations of arm nonuse. This approach shows promise for determining the efficacy of interventions designed toreduce paretic arm nonuse and enhance functional recovery after stroke. We show that the BARTR satisfies thecriteria of an appropriate metric for neurorehabilitative contexts: It is valid, reliable, and simple to use.