Fig 2. Example simulated lower-limb swing kinematics and torques during the pendulum test.
Model parameters are reported in the table. Relative length is with respect to the length of the generic model [14], mass is the mass of the lower leg, and lc is the distance between the knee joint center and the center of mass of the lower leg. (A) Lower leg segment actuated with a passive torque consisting of a damping torque, Td (damping constant B); and a coordinate limit torque, Tlim. (B) Lower leg segment actuated by a passive torque and a baseline torque representing muscle tone, Tb = 2Nm. (C) Lower leg segment actuated by a passive torque and a baseline torque when muscle short-range stiffness is accounted for by TSRS (short-range stiffness constant kSRS). (D) Lower leg segment actuated by a passive torque, a baseline torque, a short-range stiffness torque and a delayed sensory feedback torque to simulate reflex activity, TR (torque and derivative of torque reflex gains kT and kdT). (E) Lower leg segment actuated by a passive torque, a baseline torque, and a delayed sensory feedback torque. (F) Lower leg segment actuated by a passive torque and a delayed sensory feedback torque.