Normative Percentile Ranking Best Reveals Sensorimotor Impairments Of Postural Sway In Type 2 Diabetes

PURPOSE: This investigation compared the findings of three statistical methods to assess what each reveal about the sensory impairments of T2D. METHODS: Two groups of 21 were recruited for this study. T2D group - 10 adults with T2D (mean age 55.16 ± 8.1 years) were recruited from a physician's office. Comparison group - 10 healthy sex age matched adults who had participated in a previous study. Each T2D participant had anthropologic measurements and neuropathy scores. Participants completed the modified Clinical Test of Sensory Integration of Balance (mCTSIB) by standing as still as they can on a portable balance plate for four 20-sec trials. Each trail altered either the vision (eyes open or closed), surface (solid or foam), or both. Participant path lengths and percentile rank scores were recorded for each trail. Separate 2-Way, mixed model ANOVAs (2x4) were conducted for path length and percentile ranks. Follow-up, pairwise t-tests were used to evaluate differences between conditions. Frequency plots were used to display the distribution of percentile ranks of the T2D group for the four trials into four bins (0-25%, 26-50%, 51-75%, 76-100%). RESULTS: A significant main effect (p < 0.05) was found between groups for both path length and percentile rank, with the T2D group performing worse. A significant main effect (p < 0.001) between conditions was found for path length. Pairwise testing revealed increased path length in each subsequent condition (p < 0.05). No specific interactions between groups and conditions for either path length or percentile rank was found (p > 0.05). The frequency plot revealed that a majority of the T2D group ranked below the 50th percentile in all conditions. The vestibular condition was the only condition to follow a bimodal distribution. CONCLUSIONS: These findings show that examining the postural sensory impairments in T2D with an individualized normative approach should be used to provide effective patient-centered care. Though limited, the findings also suggest that impairments to the vestibular system may have a more drastic effect on postural stability than the proprioceptive or visual system.