Gait Deviations Associated With Concussion: A Systematic Review.

BACKGROUND: Gait deviations resulting from concussion are important to consider in the diagnosis, treatment progression, and return to activity after a concussion. OBJECTIVE: To identify quantifiable gait deviations associated with concussion across populations and time since injury. METHODS AND MATERIALS: Six electronic databases were systematically searched from January 1974 to September 2016. Studies selected included original data, had an analytic design, and reported a quantifiable gait parameter in individuals who had sustained a concussion as defined by the American Congress of Rehabilitation Medicine or related definitions. Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines were followed. Two independent authors assessed study quality [Downs and Black (DB) criteria] and level of evidence (Oxford Center of Evidence-Based Medicine Model). RESULTS: Of 2650 potentially relevant articles, 21 level 4 studies were included. The median DB score was 12/33 (range 10-16). Heterogeneity in gait parameters and timing of postconcussion testing precluded meta-analysis. There is consistent level 4 evidence of increased medial-lateral center-of-mass displacement, and inconsistent level 4 evidence of decreased gait velocity after concussion. Further, there is preliminary level 4 evidence that gait deficits may exist beyond the typical 10-day recovery period and return to activity. CONCLUSION: These findings suggest that individuals who have suffered a concussion may sway more in the frontal plane, and walk slower compared to healthy controls. Consensus about the most important gait parameters for concussion diagnosis and clinical management are lacking. Further, high-quality prospective cohort studies evaluating changes in gait from time of concussion to return to activity, sport, recreation and/or work are needed.

Re-conceptualizing postural control assessment in sport-related concussion: Transitioning from the reflex/hierarchical model to the systems model.

Background: While postural control impairment is common following sport-related concussion, few investigations have studied the physiological basis for this impairment. Both the Reflex/Hierarchical Model and the Systems Model are commonly used to characterize the physiological basis of postural control.Purpose: To discuss the physiological basis of postural control impairment resulting from sport-related concussion based on these models and suggest directions for future research.Methods: Narrative literature review.Findings: Postural control impairment seen with sport-related concussion is a multifaceted construct that can result from deficits in numerous systems that underlie postural control as described by the Systems Model, rather than a unidimensional construct that stems from the central nervous systems' inability to integrate sensory input to control posture as per the Reflex/Hierarchical Model.Conclusion: We recommend a transition away from the Hierarchical/Reflex Model of postural control towards the Systems Model in the conceptualization of sport-related concussion. Future research on postural control following sport-related concussion should account for the multifaceted nature of the resulting postural control impairment based on the Systems Model. Clinically, there is a need for a clinical postural control test that allows examination across the affected systems under single-task, dual-task, and sport-specific paradigms.

THE RELIABILITY OF CLINICAL BALANCE TESTS UNDER SINGLE-TASK AND DUAL-TASK TESTING PARADIGMS IN UNINJURED ACTIVE YOUTH AND YOUNG ADULTS.

BACKGROUND: Previous researchers have suggested that balance control deficits are detected more accurately with dual-task testing than single-task testing. However, it is necessary to examine the clinimetric properties of dual-task testing before employing it in clinical and research settings. OBJECTIVE: To examine and compare the relative and absolute reliability of the Balance Error Scoring System (BESS), Tandem Gait Test (TGT), and Clinical Reaction Time (CRT) under single and dual-task conditions in uninjured active youth and young adults.Study Design: Single-group, repeated-measures study. METHODS: Twenty-three individuals [9 female; median age 17 years] completed three trials of the BESS, TGT, and CRT under single and dual-task testing conditions during testing session one. Two raters assessed participants to assess inter-rater reliability. Either later on the same day or the following day, the protocol was repeated by one rater to assess intra-rater reliability. The average of three trials was used to calculate intra-rater (between-session) and inter-rater (within-session) intraclass correlation coefficient (ICC), standard error of measurement (SEM), minimal detectable change (MDC), and Cohen's Kappa coefficient for tests as appropriate under both conditions. Bland-Altman plots (mean difference and 95% limits of agreement) were used to assess for a systematic error associated with a learning effect. RESULTS: Only one participant attended the second session on the following day, while 22 participants (95%) attended the second session within four hours after testing session one. Under single-task testing, estimated ICCs, SEMs, MDCs, and Kappa coefficients ranged from 0.24 to 0.99, 0.3 to 23, 0.8 to 64, and 0.03 to 0.64, respectively. Under dual-task testing, estimated ICCs, SEMs, MDCs, and Kappa coefficients ranged from 0.70 to 0.99, 0.4 to 17, 1.1 to 47, and 0.39 to 0.83, respectively. A learning effect was identified for all tests under all conditions. CONCLUSION: The BESS is the only clinical test that demonstrated acceptable reliability for clinical use under single-task testing conditions. The BESS, TGT, and CRT all demonstrated acceptable reliability for clinical use under dual-task testing conditions. A practice session should be used to reduce the possible learning effect seen. Further studies examining sources of the systematic error observed are needed. LEVEL OF EVIDENCE: 2b.