Objective Turning Measures Improve Diagnostic Accuracy and Relate to Simulated Real-World Mobility/Combat Readiness in Chronic Mild Traumatic Brain Injury.

Balance and mobility problems are common consequences after mild traumatic brain injury (mTBI). However, turning and nonstraight gait, which are required for daily living, are rarely assessed in clinical tests of function after mTBI. Therefore, the primary goals of this study were to assess (1) the added value of clinic-based turning task variables, obtained using wearable sensors, over standard general assessments of mobility, and (2) assess the associations between general assessments of mobility, objective variables from clinic-based turning tasks, and ecologically relevant functional tasks. Fifty-three civilians with mTBI, 57 healthy civilian controls, and 36 healthy active-duty military controls participated across three sites. Participants were tested in a single session that encompassed self-reported questionnaires including demographic information and balance and mobility testing including the use of wearable sensors. Lasso regression models and the area under the receiver-operator characteristic curve (AUC) assessed diagnostic accuracy. Partial correlation coefficients assessed the relationship between each variable with ecologically relevant functional tasks. Multivariate models revealed high diagnostic accuracy, with an AUC of 0.92, using multiple variables from instrumented clinic-based turning tasks. The complex turning course (CTC) yielded the highest multivariate AUC (95% confidence interval [CI]) of 0.90 (0.84, 0.95) for a single task, and the average lap time from the CTC had the highest univariate AUC (95% CI) of 0.70 (0.58, 0.78). Turning variables provided added value, indicated by higher AUCs, over standard general assessments of mobility. Turning variables had strong associations with ecologically relevant functional tasks and outperformed general assessments of mobility, though there were slight differences in the relationship based on civilian versus military population. Clinic-based turning tasks, especially the CTC and modified Illinois Agility Test (mIAT), have high diagnostic accuracy, strong associations with ecologically relevant functional tasks, and require relatively short time(s) to complete. Compared to general assessments of mobility, clinic-based turning tasks may be more ecologically relevant to daily function. Future work should continue to examine the CTC and mIAT alongside other promising tools for return-to-activity assessments.