Reliability of static and dynamic balance tests in subjects with myotonic dystrophy type 1

Abstract

The aim of this study was to evaluate test–retest reliability of balance tests and timed walking in individuals with myotonic dystrophy type 1 (DM1). Assessments of static and dynamic balance including timed walking were repeated on three occasions with 1-week intervals. A sample of 10 individuals with functional impairment due to the DM1 disorder participated. The inclusion criteria were: age 20–60; genetically proven DM1 and ability to perform Timed Up&Go (TUG) with or without handheld aids. One Leg and Tandem Stance were assessed as well as Timed 10-m walk (comfortable/maximum pace), TUG, Step Test and Walking in a Figure-of-Eight (Fo8). The analysis of relative reliability comprised the intraclass correlation coefficient (ICC2,1); the analysis of disagreement comprised the standard error of measurement, the repeatability and the measurement error. Mean age of the participants was 42.7 years (± 10.7 years). The ICC was good to high (0.83–0.98) for all tests except Fo8. The analysis of disagreement showed that the dynamic balance tests were more reliable than the static tests. We recommend the use of the dynamic balance tests Step Test and TUG, together with the Timed 10-m walk at maximum pace to evaluate balance performance quantitatively during walking in patients with DM1.