Fig. 4

Muscle activity and torque from the intact leg. TF07 was removed from all parts of this figure (A-D) because of movement artifact in the vastus medialis EMG signal. (A) Normalized EMG from the intact-side vastus medialis muscle, shown from 0 to 120% of sit-down completion with passive (gray) and powered (black) prostheses. Lines indicate across-subject means and shading indicates standard error (N=9 subjects). (B) EMG peak (left) and EMG integral (right) between 0 and 100% of sit-down completion. Bar heights indicate across-subject means and error bars indicate standard errors (N=9 subjects). Colored dots overlaid on the bar plots indicate single-subject means (3 trials per subject). The legend on the right shows which colored dot corresponds with each subject. (C) Intact knee torque calculated using inverse dynamics. Shown during sit-down with passive (gray) and powered (black) prostheses for subjects who did not use hands (excluding TF07), from 0 to 120% of sit-down completion. Knee extension torque is negative. Lines indicate across-subject means and shading indicates standard error (N=6 subjects). (D) Relation between intact knee position and intact knee torque for all subjects who did not use hands (excluding TF07). Shown during sit-down with passive (gray) and powered (black) prostheses for subjects who did not use hands, from 0 to 100% of sit-down completion. Lines indicate across-subject means and shading indicates standard error (N=6 subjects). Circle indicates start of the movement (standing), square indicates the end of the movement (sitting)