Differences in postural control and muscle activation in individuals with bilateral and unilateral chronic ankle instability.

BACKGROUND

Individuals with chronic ankle instability (CAI) exhibit deficits in postural control and muscle activation, with bilateral changes suggesting central alterations in sensorimotor function. However, differences in postural control and muscle activation between bilateral and unilateral CAI remain unclear. Understanding these differences is crucial for developing targeted rehabilitation strategies.

RESEARCH QUESTION: Do individuals with bilateral CAI, unilateral CAI, and healthy controls have differences in postural control and muscle activation?

METHODS

18 individuals with bilateral CAI (bilateral), 18 individuals with unilateral CAI (unilateral), and 18 healthy controls (control) were recruited. To assess center of pressure (COP) and integrated electromyography (iEMG), participants performed 3 trials of single-leg stance tasks and lower extremity muscle activation was recorded simultaneously. One-way ANOVA was used to assess differences in the self-reported functional outcomes, postural control, and muscle activation among the three groups.

RESULTS

The bilateral group showed worse postural control in COP mediolateral velocity and COP anteroposterior velocity compared to the unilateral and control groups. However, the unilateral group showed similar postural control with the control group. The bilateral group showed greater iEMG in the tibialis anterior compared to the unilateral and control groups. The unilateral group showed lower iEMG in the tibialis anterior compared to the control group.

SIGNIFICANCE: Individuals with bilateral and unilateral CAI show significant differences in postural control and muscle activation during single-leg stance, suggesting that the central nervous system may process sensorimotor function differently. Understanding these differences can guide personalized treatments, which may enhance patient outcomes and reduce recurrent sprain risk.