Fig. 3

Bland–Altman plots. Comparison of the difference between the two methods of measurement (smartphone applications and three-dimensional motion analysis system) versus the mean of the two methods. The mean difference is given by the solid line. The limits of agreement are given by the ± 2SD limits: a sitting hip internal rotation; b sitting hip external rotation; c prone hip internal rotation; d prone hip external rotation; e supine hip internal rotation; and f supine hip external rotation