Figure 5.
(A) Time courses of joint angle (top) and torque (bottom) during 25° wrist flexion movements while the robot simulated a 0.15 Nm/deg position-dependent load. (B) We estimated the realized spring constants for two simulated loads (0.075 and 0.15 Nm/degree; dashed black and gray lines respectively) by fitting a line to the joint torque and wrist angle data (solid lines). The realized stiffness of the two spring-like loads were 0.059 and 0.134 Nm/degree (average error: 16%; r2 > 0.95 in both cases).