The Correlation Between Ankle Somatosensory Acuity and Sensory Organisation in Postural Stability

The sensory organisation test (SOT) and active movement extent discrimination assessment (AMEDA) are commonly used tools to assess postural stability and somatosensory acuity. Research on the relationship between these assessments is limited. This study aimed to explore the relationship between ankle somatosensation and postural stability in healthy adults. Participants completed one assessment of ankle somatosensory acuity (AMEDA) and one assessment of postural stability (SOT). Ankle somatosensory acuity was assessed on the non-dominant foot and measured their ability to detected small changes in joint movement within the inversion/eversion plane. The SOT involved both feet upon the testing platform and six "conditions" which distorted the sensory systems and assessed the ability to use visual, somatosensory, and vestibular feedback to maintain postural control. A Spearman's Rank-Order Correlation was run to assess the relationship between AMEDA and SOT measures. We hypothesised that AMEDA scores would positively correlate with SOT conditions 4-6 (sway-referenced platform for all) and the somatosensory (SOM) sensory score. 54 participants (28 females, 26 males; mean age 40 ± 14 years) completed the study. Positive correlations were found between the AMEDA score and SOT conditions 5 (eyes closed, sway-reference platform) and 6 scores (sway-referenced visual surround and platform) (p = .041 and p = .006) but not with SOT condition 4 (eyes open, sway-referenced platform) or the SOM sensory score (p > .05). There were positive correlations between the AMEDA score, and SOT composite score and vestibular (VEST) sensory score (p < .001 and p = .007). Somatosensation and postural stability scores were related during the most challenging balance tasks, highlighting the role of somatosensory acuity in postural control. However, AMEDA score did not relate to the SOM scores in the SOT, suggesting different factors influence these measures of somatosensation. This highlights the unique contributions of the AMEDA and SOT in assessing sensory function and its impact on balance.