Fig. 2

Average trajectories of the BCoM during (a-d) level walking and (e-h) walking at 100% of the customary speed during level or decline walking. The average trajectories represent right-legged trans-tibial amputees [where participants were left-leg amputees, the BCoM trajectories were reflected in the sagittal (x-y) plane]. a 3D-BCoM trajectories during level walking at 80–160% customary speed, and b-d 2D-BCoM trajectories during level walking at 80, 120 and 160% customary speed, for each prosthetic foot attachment condition (red hyA-F, blue rigF; see also legend). e 3D-BCoM trajectories, and f-h 2D-BCoM trajectories, walking at 100% of the customary speed on level, 5° decline and 10° decline. On the plots (a, b, c, e, f, g), for each condition (speed or decline), trajectories are incrementally offset on the craniocaudal axis (y-axis) by 30 mm for level walking and 50 mm for decline walking, for clarity. On the 3D-plots, the subject is walking from lower-left to upper-right along the anteroposterior axis (x-axis); hence positive medio-lateral (‘z’) displacement represents rightwards movement and negative ‘z- displacement represents leftwards movement. Movies of the rotation of the 3D trajectories of the BCoM are available as Additional files (see https://doi.org/10.5518/272)