Contralateral force sense deficits are related to the presence of functional ankle instability.

Residual symptoms that often follow lateral ankle sprains can lead to functional ankle instability. Proprioceptive deficits have been identified as one factor that may contribute to the presence of functional ankle instability. Sixty participants were recruited to participate in the study. Seven questions were used to determine the presence of functional ankle instability in each participant. A point was added for each "yes" response to produce an index that represents an interval data scale of functional ankle instability. Contralateral force sense and active joint reposition sense were measured in all participants. Pearson product moment correlations were calculated to determine the relationship between functional ankle instability and force sense and active joint reposition sense. We found a significant relationship with force sense and functional ankle instability. Specifically, force sense variable error at both test forces (10 and 30% of maximal voluntary isometric contraction) were positively correlated to the presence of functional ankle instability, r=0.26; p<or=0.05 and r=0.25; p<or=0.05, respectively. All other force sense correlations were not statistically significant. No significant correlations were identified between active joint reposition sense and functional ankle instability. This study indicates that participants with functional ankle instability have deficits in low load force sense, but not active joint reposition sense. Copyright (c) 2006 Orthopaedic Research Society.