Fig. 6.

Superposition tests for (a) toe off (TO) and (b) early swing phase (ES) postures. Each graph is a scatter plot of calculated accelerations (by addition of RF and VM induced acceleration responses) versus measured accelerations (the response to simultaneous stimulation of RF and VM). The theoretical relationship between these two variables, assuming superposition, is calculated acceleration = 1*measured acceleration. Best-fit lines with 0 intercept (solid lines) are compared to the theoretical relationship (dashed lines). Best-fit lines are close to the theoretical relationship (coefficients ≈1) and coefficients of determination are high (R² ≥ 80%) in all cases.