Ankle laxity and instability in collegiate swimmers.

Background: Ankle flexibility is important in maximizing a swimmer's kicking speed. The effects of increased ankle flexibility in swimmers has not been documented in the literature. The goal of this study is to evaluate ankle laxity, flexibility, and instability in college swimmers compared to control runners.

Methods: This is an observational, cross-sectional study conducted on collegiate athletes. Participants included 41 collegiate Division I volunteer swimmers and runners between the ages 18 and 23 recruited from a Division I college. Participants were assessed for ankle laxity using ankle physical examination maneuvers such as the anterior drawer and talar tilt test. Ankle flexibility and range of motion through ankle dorsiflexion, plantarflexion, inversion, and eversion were measured using a goniometer. Ankle instability was assessed through the CAIT survey.

Results: There was no difference in incidence of injury rates between swimmers and runners. Swimmers demonstrated a positive tilt test (defined as no clear end point) at significantly higher rates than runners). Swimmers demonstrated significantly greater ankle ROM than runner controls in plantarflexion, inversion in neutral, inversion in plantarflexion, eversion in neutral, and eversion in plantarflexion (t=-6.770, P<0.001; t=-4.140, P<0.001; t=-5.293, P<0.001; t=-2.153, P=0.017; t=-3.351, P<0.001). Finally, swimmers also demonstrated lower CAIT scores than control runners (24.78 and 26.79), which equates to greater degrees of ankle instability (t=-2.142, P=0.035).

Conclusions: Although ankle injuries are not common in swimmers, swimmers demonstrate significantly increased ankle flexibility, laxity, and instability compared to runner controls. It is not clear what the significance of these findings are yet; however, it is possible that increased laxity and instability in swimmers' ankles may predispose to ankle injuries in the future, especially swimmers cross-train on land or switch to land-based sports. More research is required to investigate the relationship between ankle laxity and instability in swimmers and injury risk through longitudinal cohort studies.