Effects of Swelling on Static and Dynamic Postural Control and Patient-Reported Outcomes in Individuals With Chronic Ankle Instability.

OBJECTIVE

To investigate the effects of swelling on postural control and patient-reported outcomes in individuals with chronic ankle instability (CAI).

DESIGN

Cross-sectional study.

SETTING

Controlled laboratory.

PARTICIPANTS

A total of 60 participants-20 CAI individuals with swelling (swelling), 20 CAI individuals without swelling (nonswelling), and 20 healthy controls (control)-were recruited.

INDEPENDENT VARIABLES: Group (swelling, nonswelling, and control).

MAIN OUTCOME MEASURES: Participants performed 3 trials of single-leg hop-to-stabilization and single-leg stance tasks, along with patient-reported outcomes. A one-way analysis of variance was used to assess group differences in dynamic and static postural control and patient-reported outcomes.

RESULTS

The swelling group exhibited worse dynamic postural control in vertical stability index and dynamic postural stability index compared with the nonswelling ( P = 0.03, P = 0.04) and control ( P < 0.01 and P < 0.01) groups. The nonswelling group showed similar dynamic postural control with the control group. Swelling ( P < 0.01 and P < 0.01) and nonswelling ( P = 0.01 and P < 0.01) groups showed worse static postural control center of pressure mediolateral velocity and center of pressure anteroposterior velocity compared with the control group. Swelling and nonswelling groups showed differences in patient-reported outcomes about ankle function and instability compared with the control group, but there was no difference in patient-reported outcomes between the swelling and nonswelling groups themselves.

CONCLUSION

Ankle swelling contributes to altered neuromuscular control, resulting in worse dynamic postural control, but affects neither static postural control nor patient-reported outcomes in CAI individuals.