Reactive Balance Responses After Mild Traumatic Brain Injury: A Scoping Review

Abstract

Balance testing after concussion or mild traumatic brain injury (mTBI) can be useful in determining acute and chronic neuromuscular deficits that are unapparent from symptom scores or cognitive testing alone. Current assessments of balance do not comprehensively evaluate all 3 classes of balance: maintaining a posture; voluntary movement; and reactive postural response. Despite the utility of reactive postural responses in predicting fall risk in other balance-impaired populations, the effect of mTBI on reactive postural responses remains unclear. This review sought to (1) examine the extent and range of available research on reactive postural responses in people post-mTBI and (2) determine whether reactive postural responses (balance recovery) are affected by mTBI. Design: Scoping review. Methods: Studies were identified using MEDLINE, EMBASE, CINAHL, Cochrane Library, Dissertations and Theses Global, PsycINFO, SportDiscus, and Web of Science. Inclusion criteria were injury classified as mTBI with no confounding central or peripheral nervous system dysfunction beyond those stemming from the mTBI, quantitative measure of reactive postural response, and a discrete, externally driven perturbation was used to test reactive postural response. Results: A total of 4747 publications were identified, and a total of 3 studies (5 publications) were included in the review. Conclusion: The limited number of studies available on this topic highlights the lack of investigation on reactive postural responses after mTBI. This review provides a new direction for balance assessments after mTBI and recommends incorporating all 3 classes of postural control in future research.

Acute and Longitudinal Effects of Sport-related Concussion on Reactive Balance

“…The limited prior work on reactive balance post-concussion has predominantly employed standing platform perturbations to investigate the cross-sectional and chronic effects of concussion (i.e., mild traumatic brain injury) on reactive balance performance 5 . Pan et al 14 provided preliminary evidence that individuals experiencing persistent symptoms after concussion exhibit impaired reactive balance in response to a sliding platform perturbation.…”

“…A comprehensive understanding of balance includes several factors that influence individuals' ability to stand, move, react, and engage with their surroundings 3,4 . These factors manifest within three primary domains of balance activities: static balance, dynamic balance, and reactive balance 5 . In concussion evaluations, the BESS test specifically targets static balance, defined as the ability to maintain equilibrium and control the center of mass in relation to a fixed base of support 6 .…”

“…Reactive balance relies on interactions among spinal circuits, the brainstem, and the cerebral cortex 11 to coordinate responses to sudden unexpected alterations in the base of support or center of mass kinematics. In contrast to static and dynamic balance tasks, reactive balance is initiated faster than voluntary movement and leaves little time for iterative corrections 5,12 . Instead, responses can be primed based on experiential learning in advance of the perturbation, and triggered (i.e., executed) promptly upon a loss of balance.…”

Reactive Postural Responses Predict Risk For Acute Musculoskeletal Injury In Collegiate Athletes

“…Clinical assessments that probe neuromechanical responses, including the identification of a sensory stimuli; integration of multiple senses; and short-, medium-, and long-latency responses to achieve fast, yet precise motion are promising, but under-utilized, avenues for identifying athletes at risk for future acute MSK injury particularly under dual-task conditions. 18,19 The purpose of this study was to examine if reactive postural responses (i.e., the neuromechanical responses to a loss of stability) are associated with the risk for acute lower extremity MSK injuries in collegiate athletes. 18 Reactive postural responses occur when there is a sudden change in posture or support surface, are shaped by the pre-perturbation neuromotor state (i.e.…”

“…Clinical assessments that probe neuromechanical responses, including the identification of a sensory stimuli; integration of multiple senses; and short-, medium-, and long-latency responses to achieve fast, yet precise motion are promising, but under-utilized, avenues for identifying athletes at risk for future acute MSK injury particularly under dual-task conditions. 18, 19…”