Single Trial Within-Session Reliability of the Balance Tracking System Limits of Stability Protocol for Persons With Type 2 Diabetes Mellitus

The purpose of this study was to assess the reliability of the Balance Tracking System (BTrackS) Limits of Stability (BLOS) protocol among individuals with Type 2 Diabetes Mellitus (T2D). This cross-sectional study had participants complete two trials of the BLOS test during one session, where they were instructed to keep both feet planted on the force plate while moving their center of pressure in all directions as far as they could. Recruitment and data collection was conducted at a local endocrinology practice. This study recruited 72 (36 male, 36 female) participants with T2D that could walk unassisted and did not have any lower limb replacements or injuries. Total area of exploration and laterality bias were calculated for each trial. Within-session reliability was assessed using intraclass correlation coefficients (ICC (2, 1) and ICC (2,k)) to evaluate both single-trial and averaged performance. The total area of exploration demonstrated good-to-excellent single-trial reliability (ICC (2, 1) = 0.82) and excellent reliability when averaged across trials (ICC (2, k) = 0.90). Laterality bias demonstrated moderate single-trial reliability (ICC (2, 1) = 0.56) and improved reliability when averaged (ICC (2, k) = 0.73). The BLOS appears to be a reliable measure of postural control in individuals with T2D. These findings support the potential feasibility of a single-trial assessment for total area, while laterality bias should be interpreted with greater caution.