Laura Peeters

The trunk in Duchenne Muscular Dystrophy | 79 4 sEMG amplitudes. Subsequently, average muscle activity of the back muscles (i.e. longissimus and iliocostalis both sides) and average activity of the abdominal muscles (i.e. external oblique both sides) were calculated. If there were more than two missing values, i.e. trials that failed due to inability of the participant to perform the task, or technical errors such as missing signals due to loose electrodes, the average muscle activity was defined as missing value. All analyses were performed using Matlab R2014b (Math Works, USA) software. Statistics Non-parametric tests were used since most of the data were not normally distributed. Median values and interquartile ranges were used to describe the participant characteristics. Wilcoxon rank sum test was used to assess differences between DMD patients and HC and the Kruskal-Wallis test to assess differences between DMD patients with different scores on the Brooke scale. To test the hypotheses that compensatory trunk ROM would increase with task difficulty, trunk ROM when reaching without weight was subtracted from trunk ROM when reaching with 500 gram object for each individual. Afterwards the change in trunk ROM between DMD patients and HC was assessed with the Wilcoxon rank sum test. The range of motion is depicted in graphs, where the boxes represent 25 th , 50 th and 75 th percentile, whiskers minimum and maximum non-outlier values and dots indicate outliers (greater than 1.5 times the interquartile range). All statistical analyses were performed using Matlab R2014b (Math Works, USA) and the statistical significance level was set at α = 0.05. RESULTS Subject demographics. Participant characteristics are described in Table 1. Of the corticosteroid users, three patients used Deflazacort and the others used Prednisolone. TheVignos classifications of the DMD participants were: 1 (n=1), 2 (n=1), 3 (n=1), 4 (n=1), 5 (n=2), 7 (n=2) and 9 (n=9); and the Brooke classifications: 1 (n=6), 2 (n=6), 3 (n=5). One DMD participant left the assessment before the protocol was finished and was therefore excluded from the analysis. Termination of the measurement was unrelated to the protocol or measurement itself.