A hill-type muscle model expansion accounting for effects of varying transverse muscle load

Simulations using Gc overestimated ΔFim (up to 59%) and Δh (up to 136%) for increasing load. Although the model assumption (equal G for forces and length changes) held for the three lower loads using Gexp and Gf, simulations resulted in underestimation of ΔFim by 38% and overestimation of Δh by 58% for the largest load, respectively. To simultaneously reproduce experimental ΔFim and Δh for the two larger loads, it was necessary to reduce Fim by 1.9% and 4.6%, respectively. The model seems applicable to account for effects of muscle deformation within a range of transverse loading when using a linear load-dependent function for G.