There is a need for better tools to objectively, reliably, and precisely assess neurological function after sport-related concussion (SRC). The aim of this study was to use a robotic device (Kinesiological Instrument for Normal and Altered Reaching Movements; KINARM) to quantify neurological impairments in athletes acutely and when clinically asymptomatic post-SRC. Robotic assessments included five KINARM standard tasks that evaluate aspects of motor, sensory, and cognitive function. We hypothesized that acutely concussed athletes would demonstrate significant rates of impairment on the robotic assessment, and that impairments would be associated with acute symptom severity. Pre-season assessments were conducted from 2011 to 2016 on 1051 athletes. Eighty-four athletes were reassessed acutely (≤10 days post-injury) and while symptomatic post-SRC and 89 when clinically asymptomatic. Forty-four parameters were measured from the KINARM assessment to characterize neurological function. Reliable change indices (80% confidence interval) identified impairments in healthy and concussed individuals for each parameter. In concussed individuals, impairment rate varied across parameters from 4% to 27% at the acute time point and from 2% to 18% when clinically asymptomatic. Healthy athlete impairment rates were between 2% and 16% across all testing time points. We identified relationships between acute symptom severity and task performance for only two parameters, both of which evaluated attributes of motor function. Overall, the KINARM identified impairments in motor, sensory, and cognitive function in athletes with SRC; however, impairment rates were low and largely did not relate to symptom severity. More complex tasks may be necessary to identify potentially subtle neurological impairments post-SRC.

BackgroundCurrent assessment tools for sport-related concussion are limited by a reliance on subjective interpretation and patient symptom reporting. Robotic assessments may provide more objective and precise measures of neurological function than traditional clinical tests.ObjectiveTo determine the reliability of assessments of sensory, motor and cognitive function conducted with the KINARM end-point robotic device in young adult elite athletes.MethodsSixty-four randomly selected healthy, young adult elite athletes participated. Twenty-five individuals (25 M, mean age±SD, 20.2±2.1 years) participated in a within-season study, where three assessments were conducted within a single season (assessments labeled by session: S1, S2, S3). An additional 39 individuals (28M; 22.8±6.0 years) participated in a year-to-year study, where annual pre-season assessments were conducted for three consecutive seasons (assessments labeled by year: Y1, Y2, Y3). Forty-four parameters from five robotic tasks (Visually Guided Reaching, Position Matching, Object Hit, Object Hit and Avoid, and Trail Making B) and overall Task Scores describing performance on each task were quantified.ResultsTest-retest reliability was determined by intra-class correlation coefficients (ICCs) between the first and second, and second and third assessments. In the within-season study, ICCs were ≥0.50 for 68% of parameters between S1 and S2, 80% of parameters between S2 and S3, and for three of the five Task Scores both between S1 and S2, and S2 and S3. In the year-to-year study, ICCs were ≥0.50 for 64% of parameters between Y1 and Y2, 82% of parameters between Y2 and Y3, and for four of the five Task Scores both between Y1 and Y2, and Y2 and Y3.ConclusionsOverall, the results suggest moderate-to-good test-retest reliability for the majority of parameters measured by the KINARM robot in healthy young adult elite athletes. Future work will consider the potential use of this information for clinical assessment of concussion-related neurological deficits.

Introduction: An important problem in the field of sport-related concussion is the lack of a 'gold-standard' clinical assessment tool. Currently, the diagnosis relies heavily on self-reporting of symptoms and observation of clinical signs by medical professionals. To address this, our group has been motivated to develop objective measures of neurological impairment following concussion. Spatial working memory is an important aspect of cognitive function that might be impaired following concussion. In the present study, we measured spatial working memory using a robotic spatial span task. We first assessed test-retest reliability in 82 healthy athletes who underwent baseline testing across two athletic seasons using intraclass correlation coefficients. We then assessed spatial span performance relative to baseline in 47 athletes acutely following sport-related concussion using a reliable change index with 80% confidence limits to define impairment on an individual basis. Results: We found good test-retest reliability for the mean span (a measure of spatial working memory span length; intraclass correlation coefficient ¼ 0.79), and moderate reliability for the response duration (time taken per spatial target; intraclass correlation coefficient ¼ 0.64) in healthy athletes. However, only 19% of acutely concussed athletes showed evidence of impairment relative to baseline in mean span, and even fewer (9%) showed evidence of impairment in response duration. Analysis of serial position curves revealed primacy and recency effects for this task, but no grouplevel differences between concussed and healthy athletes. Analysis of specific types of errors showed a higher rate of substitution errors in the concussed group at baseline, suggesting possible malingering in a small number of athletes. Conclusion: Overall, few athletes showed evidence of impaired spatial working memory acutely following concussion, suggesting either that spatial working memory is not commonly impaired acutely post-concussion, or that the present task is not sufficiently demanding.

Context Sport-related concussion (SRC) often presents with multidimensional and subtle neurologic deficits that are difficult to detect with standard clinical tests. New assessment approaches that efficiently quantify deficits across multiple neurologic domains are needed. Objective To quantify impairments in postural movements during an assessment of rapid, bimanual motor ability in athletes within 10 days of experiencing an SRC and evaluate relationships between impairments in upper extremity and postural performance. Design Cohort study. Setting Sport medicine clinic. Patients or Other Participants Initial baseline assessments were completed for 711 athletes. Seventy-five athletes (age = 15.8 ± 3.3 years at baseline) sustained SRCs and were reassessed within 10 days. Seventy-eight athletes (age = 15.5 ± 2.0 years) completed 2 assessments in a healthy state. Main Outcome Measure(s) Athletes stood on force plates and performed a rapid, bimanual motor task, termed the object-hit task, delivered using a Kinesiological Instrument for Normal and Altered Reaching Movements endpoint robot. Measures of postural stability that quantified center-of-pressure movements and measures of upper extremity performance were used to characterize task performance. Results Performance changes across assessments were converted to reliable change indices (RCIs). We observed a difference in RCI values between athletes with SRC and healthy control athletes on the combined postural measures (P = .01). Using measures to evaluate the change in postural movements from the early, easier portion of the task to the later, more difficult portion, we identified the highest levels of impairment (19%–25% of the sample impaired). We also noted a difference between individuals with concussion and healthy individuals on the combined upper extremity measures (P = .003), but these impairments were largely unrelated to those identified in the postural movements. Conclusions Measurement of postural movements during the object-hit task revealed impairments in postural stability that were not related to impairments in upper extremity performance. The findings demonstrated the benefits of using assessments that simultaneously evaluate multiple domains of neurologic function (eg, upper extremity and postural control) after SRC.