Spectral analysis of centre of pressure identifies altered balance control in individuals with moderate-severe traumatic brain injury.

PURPOSE: To identify impairments and recovery of balance control after moderate-severe traumatic brain injury (TBI) through spectral analyses of static balance tasks and to characterise the contributions of each limb to balance control.

METHODS: A retrospective analysis of longitudinal balance data from force platforms at 2, 5, and 12 months post-injury in 31 individuals with moderate to severe TBI was performed. Single-visit data from age-matched controls (n = 22) were collected for descriptive comparison. Net and individual limb centre of pressure measures and inter-limb centre of pressure coherence were calculated in low (≤0.4 Hz) and high (≥0.4 Hz) frequencies in the anteroposterior and mediolateral directions during standing with the eyes open and closed.

RESULTS: Standing with the eyes closed increased net centre of pressure spectral power in low and high frequencies. Individuals with TBI demonstrated recovery in high frequencies in net centre of pressure in the mediolateral direction. Inter-limb coherence in the anteroposterior and mediolateral directions increased (recovered) over time in high frequencies. Weight-bearing asymmetry was visible in high frequencies in the anteroposterior and mediolateral directions.

CONCLUSIONS: Increased amplitude of low and high-frequency power suggests that individuals with TBI included in this study have impaired anticipatory and reactive balance mechanisms, which may be driven by weight-bearing asymmetries and which recover over time. Implications for rehabilitation Anticipatory and reactive balance impairments after traumatic brain injury may place individuals at increased risk for falls. Analyses from postural sway in static balance tasks infer changes in anticipatory or reactive balance control after traumatic brain injury. Addressing weight-bearing asymmetries in rehabilitation interventions post-traumatic brain injury may improve between-limb coordination for anticipatory and reactive balance control.