Pollet, Aviva Katherine, authorLodha, Neha, advisorLi, Kaigang, committee memberSchmid, Arlene A., committee member2022-05-302024-05-242022https://hdl.handle.net/10217/235229Overall introduction: Individuals with stroke experience motor and cognitive deficits both of which can impact driving performance. Using two separate studies, we evaluated the influence of motor and cognitive factors on driving performance in stroke survivors. In the first study, we evaluated how driving impairments in stroke survivors is influenced by the use of either the paretic or non-paretic leg for pedal control. Methods 1: Twenty-two individuals with chronic stroke were recruited in two groups depending on their lower-limb choice for pedal control 1) paretic leg drivers, individuals using their paretic leg to control the car pedals (N = 11, 68.4 ± 7.8 years) and 2) non-paretic leg drivers, individuals using their non-paretic leg to control the car pedals (N = 11, 61.1 ± 13.7 years). Both groups performed a car following task in a driving simulator. The task required participants to follow a lead car by controlling the gas pedal accurately and respond to brake lights by pressing the brake pedal as fast as possible. We quantified gas pedal error using root mean square error (RMSE). We measured brake response time as the time from the onset of the brake lights of the lead car to the application of the brake pedal. We also dissociated the brake response time into pre-motor and motor response times. We used the Driving Habits Questionnaire (DHQ) to measure self-reported on-road driving behavior. Additionally, using surface electromyography (EMG), we analyzed neuromuscular activation using burst duration and amplitude, and coordination using overlap and coactivation of the tibialis anterior (TA) and medial gastrocnemius (MG) during the braking portion of the car following task. Results 1: The paretic leg drivers showed greater gas pedal RMSE than the non-paretic leg drivers (p ≤ 0.01). The paretic leg drivers had a slower brake response time than the non-paretic leg drivers (p < 0.05). Premotor response time was not different between the two groups (p = 0.71), however, the paretic leg drivers had a significantly slower motor response time relative to the non-paretic leg drivers (p < 0.05). The paretic leg drivers had lower DHQ scores than the non-paretic leg drivers (p ≤ 0.01). DHQ and brake response time were negatively correlated (r = - 0.42, p ≤ 0.05). Additionally, paretic leg drivers showed longer TA EMG burst duration (p <0.05) and more TA-MG overlap (p <0.05). TA EMG burst duration was positively correlated to brake response time (r = 0.51, p < 0.05) and motor response time (r = 0.61, p < 0.05). TA-MG overlap was positively correlated to brake response time (r = 0.76, p = 0.001). In the second study, we evaluated how cognitive load influenced driving impairments in stroke survivors. Methods 2: Ten individuals with chronic stroke participated in the current study (N = 10, 65.6 ± 14.9 years). The participants performed simulated driving without (single-task) and with (dual-task) a cognitive load. The single-task driving required participants to drive along a rural road and brake as quickly as possible when an unexpected hazard, such as wildlife crossing into the driving lane, was encountered. The dual-task driving required participants to drive in the same driving scenario while performing a secondary cognitive task. The cognitive task involved mental arithmetic to induce higher cognitive load while driving. Specifically, participants were asked to subtract 4 and add 3 to a random number and do so repeatedly until the end of the driving task. We measured lane departures as the number of times the edge of the participant's vehicle left the designated driving lane. We measured speed compliance as the percent of total time the individual was within +/- 5 MPH of the speed limit between events. Additionally, we measured brake response time as the time from the appearance of the hazard stimulus to the application of the brake pedal. Results 2: Individuals with stroke show more lane departures throughout the entire drive during dual-task driving than single-task driving (p < 0.05). Additionally, individuals with stroke show worse speed compliance during dual-task driving than single-task driving (p < 0.05). There was no difference in brake response time between the single-task and dual-task driving (p = 0.18). Overall conclusion: Driving performance in stroke survivors is influenced by limb selection for pedal control and cognitive load. The current studies demonstrate the need to assess and train motor and cognitive deficits that contribute to driving performance in individuals with stroke. Motor deficits in pedal control and brake response time contribute to unsafe driving in individuals with stroke. Cognitive deficits in lane departures and speed compliance in driving with cognitive load also contribute to unsafe driving in individuals with stroke. To address these deficits, stroke driving rehabilitation programs should focus on driving leg and cognitive environment of driving.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Text