Vol.:(0123456789) 1 3 Experimental Brain Research https://doi.org/10.1007/s00221-018-5419-8 RESEARCH ARTICLE Biomechanical and neurocognitive performance outcomes of walking with transtibial limb loss while challenged by a concurrent task Alison L. Pruziner 1,2,3  · Emma P. Shaw 2,4,5  · Jeremy C. Rietschel 4,6  · Brad D. Hendershot 1,2,3  · Matthew W. Miller 7  · Erik J. Wolf 1,2,3  · Bradley D. Hatfeld 4,5  · Christopher L. Dearth 1,2,3,8  · Rodolphe J. Gentili 4,5,9 Received: 19 March 2018 / Accepted: 26 October 2018 © This is a U.S. government work and its text is not subject to copyright protection in the United States; however, its text may be subject to foreign copyright protection 2018 Abstract Individuals who have sustained loss of a lower limb may require adaptations in sensorimotor and control systems to efectively utilize a prosthesis, and the interaction of these systems during walking is not clearly understood for this patient population. The aim of this study was to concurrently evaluate temporospatial gait mechanics and cortical dynamics in a population with and without unilateral transtibial limb loss (TT). Utilizing motion capture and electroencephalography, these outcomes were simultaneously collected while participants with and without TT completed a concurrent task of varying difculty (low- and high-demand) while seated and walking. All participants demonstrated a wider base of support and more stable gait pattern when walking and completing the high-demand concurrent task. The cortical dynamics were similarly modulated by the task demand for both groups, to include a decrease in the novelty-P3 component and increase in the frontal theta/parietal alpha ratio power when completing the high-demand task, although specifc diferences were also observed. These fndings confrm and extend prior eforts indicating that dual-task walking can negatively afect walking mechanics and/or neurocognitive performance. However, there may be limited additional cognitive and/or biomechanical impact of utilizing a prosthesis in a stable, protected environment in TT who have acclimated to ambulating with a prosthesis. These results highlight the need for future work to evaluate interactions between these cognitive–motor control systems for individuals with more proximal levels of lower limb loss, and in more challenging (ecologically valid) environments. Keywords Limb loss · Cognitive workload · Biomechanics · Electroencephalogram · Dual-task walking Abbreviations ANOVA Analysis of variance CAREN Computer-Assisted Rehabilitation ENvironment EEG Electroencephalography ERPs Event-related potentials FT/PA Frontal theta/parietal alpha ratio NASA-TLX National Aeronautics and Space Adminis- tration-Task Load Index TT Transtibial limb loss Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00221-018-5419-8) contains supplementary material, which is available to authorized users. * Alison L. Pruziner alison.l.pruziner.civ@mail.mil 1 DoD-VA Extremity Trauma and Amputation Center of Excellence, Bethesda, MD, USA 2 Department of Rehabilitation, Walter Reed National Military Medical Center, Bethesda, MD, USA 3 Department of Rehabilitation Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA 4 Department of Kinesiology, School of Public Health, University of Maryland, College Park, MD, USA 5 Neuroscience and Cognitive Science Program, University of Maryland, College Park, MD, USA 6 Baltimore Veterans Administration Medical Center, Baltimore, MD, USA 7 Center for Neuroscience, School of Kinesiology, Auburn University, Auburn, AL, USA 8 Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, USA 9 Maryland Robotics Center, University of Maryland, College Park, MD, USA