Figure 4

Bland-Altman plots and heteroscedasticity. Data points represent data from each participant with SCI. A. Bland-Altman plots for agreement of mean absolute angle errors between two separate days of testing for the hip and knee joints. The difference between the two test sessions is plotted versus the mean of the test sessions across days. The 95% confidence intervals of the mean difference between test days are shown as dashed lines. The 95% limits of agreement are shown as dotted lines. B. Heteroscedasticity plots for the hip and knee joints in subjects with SCI. There is a positive relationship between the absolute difference and the average of the test session across the two days of testing (hip: P = 0.003; knee: P = 0.031).