Diminished postural stability is a risk factor for ankle sprain occurrence and ankle sprains result in impaired postural stability. To date, ankle sprain history has not been taken into account as a determinant of postural stability, while it could possibly specify subgroups of interest. Methods: Postural stability was compared between 18 field hockey athletes who had recovered from an ankle sprain (mean (SD); 3.6 (1.5) months post-injury), and 16 uninjured controls. Force plate and kinematics parameters were calculated during single-leg standing: mean center of pressure speed, mean absolute horizontal ground reaction force, mean absolute ankle angular velocity, and mean absolute hip angular velocity. Additionally, cluster analysis was applied to the `injured` participants, and the cluster with diminished postural stability was compared to the other participants with respect to ankle sprain history. Findings: MANCOVA showed no significant difference between groups in postural stability (P = 0.68). A self-reported history of an (partial) ankle ligament rupture was typically present in the cluster with diminished postural stability. Subsequently, a `preceding rupture` was added as a factor in the MANCOVA, which showed a significant association between diminished postural stability and a `preceding rupture` (P = 0.01), for all four individual parameters (P: 0.001-0.029; Cohen's d: 0.96-2.23). Interpretation: Diminished postural stability is not apparent in all previously injured athletes. However, our analysis suggests that an (mild) ankle sprain with a preceding severe ankle sprain is associated with impaired balance ability. Therefore, sensorimotor training may be emphasized in this particular group and caution is warranted in return to play decisions.
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