Characterization of balance control after moderate to severe traumatic brain injury: A longitudinal recovery study

Abstract

Background. Balance impairments after traumatic brain injury (TBI) are common and persist after injury. Postural asymmetries in balance have been reported, but not quantified, across recovery. Objective. The objective of this study was to characterize balance recovery after moderate to severe TBI, with a focus on postural asymmetry. Design. A secondary analysis of prospectively collected data was used in this study. Methods. Data were from 45 participants with moderate to severe TBI. Participants' balance in 2 bipedal stances and 2 unipedal stances was assessed with force plates at approximately 2, 5, and 12 months after injury. Single-visit data from participants who were matched for age and served as healthy controls were collected for visual comparison using 95% confidence intervals. Spatial and temporal center-of-pressure (COP) measures were calculated from force plates in the anteroposterior (AP) and mediolateral (ML) directions. Results. Despite improvements in net ML COP postural sway from 2 to 5 months after injury, there were no changes in AP postural sway across recovery. Postural sway in individuals with TBI was higher than normative values at all time points in both directions. Interlimb synchrony did not change across recovery in either direction. TBI weight-bearing asymmetry was lower than normative values at all time points and did not change across recovery. The characteristics of unipedal stance differed between limbs. Limitations. Sample size was reduced as a result of the inclusion and exclusion criteria; future studies will benefit from a larger sample size. Conclusions. The absence of recovery in ML COP postural sway, interlimb synchrony, and weight-bearing symmetry indicated that reduced ML control may contribute to balance impairments after TBI. These impairments may extend to dynamic balance tasks and may also place individuals with TBI at a higher risk for falls.