Fig. 2
Symmetry coefficient groups and averaged traces. a Distribution of GRF, Fquad and FACL OC among groups. Dashed lines indicate boundaries between tertiles.. n = 17 subjects for GRF, 4 for Fquad 1, 9 for Fquad 2 and 4 for Fquad 3; 9 for ACL 1 and 8 for ACL 2. Mean traces of right (green) and left (red) lower limb stance phases for GRF (b), Fquad (c–e) and ACL (f, g). Traces represent the average of the right and left stance phases recorded from the subjects belonging to each tertile. For tertile 1 (lowest OC, worst case, c, f) it is relevant to note how, notwithstanding a symmetrical GRF (b), there is a asymmetry in the load acceptance period (within 0.2–0.3 of the stance phase) and in the subsequent pre-swing period (0.6–0.7 onwards, more evident in c). Force (Kgf) in b–g has been normalized to body weight (BW) i.e. a value of 1 means 100% BW. The stance phase (X axis) has been divided into percentiles from 0 (hill strike) to 1 (toe off). Mean traces shown in panels b–g for left and right legs were obtained by averaging the individual traces of the subjects whose OCs belonged to that tertile. In this respect, the difference between left and right legs might not be obvious by simply looking at the traces (i.e. as in f). Numerical indexes of Fquad (1, 2 and 3) and of FACL (1 and 2) refer to the OC tertile the subjects whose mean traces are plotted belong to. (i.e. c shows the mean traces of the subjects whose Fquad OC is in tertile 1)