Data from: History-dependent perturbation response in limb muscle

Muscle mediates movement but movement is typically unsteady and perturbed.
Muscle is known to behave non-linearly and with history dependent
properties during steady locomotion, but the importance of history
dependence in mediating muscles function during perturbations remains less
clear. To explore muscle's capacity to mitigate perturbations during
locomotion, we constructed a series of perturbations that varied only in
kinematic history, keeping instantaneous position, velocity and time from
stimulation constant. We find that muscle's perturbation response is
profoundly history dependent, varying by four fold as baseline frequency
changes, and dissipating energy equivalent to  ~6 times
the kinetic energy of all the limbs in 5 ms (nearly 2400 W Kg-1).
Muscle's energy dissipation during a perturbation is predicted
primarily by the force at the onset of the perturbation. This relationship
holds across different frequencies and timings of stimulation. This
history dependence behaves like a viscoelastic memory producing
perturbation responses that vary with the frequency of the underlying
movement.