Implementation of the algorithm described in
Guarín, Diego L., and Robert E. Kearney. "Estimation of Time-Varying, Intrinsic and Reflex Dynamic Joint Stiffness during Movement. Application to the Ankle Joint." Frontiers in computational neuroscience 11 (2017): 51.
Text freely avaliable here: https://www.frontiersin.org/articles/10.3389/fncom.2017.00051/full