A comparison of models of the isometric force of locust skeletal muscle in response to pulse train inputs

Muscle models are an important tool in thedevelopment of newrehabilitation and diagnostic techniques.Many models have been proposed in the past, but little workhas been done on comparing the performance of models. Inthis paper, seven models that describe the isometric forceresponse to pulse train inputs are investigated. Five of themodels are from the literature while two new models are alsopresented. Models are compared in terms of their ability to fitto isometric force data, using Akaike’s and Bayesian informationcriteria and by examining the ability of each model todescribe the underlying behaviour in response to individualpulses. Experimental data were collected by stimulating thelocust extensor tibia muscle and measuring the force generatedat the tibia. Parameters in each model were estimated byminimising the error between the modelled and actual forceresponse for a set of training data. A separate set of test data, which included physiological kick-type data, was used to assess the models. It was found that a linear model performed the worst whereas a new model was found to perform the best. The parameter sensitivity of this new model was investigated using a one-at-a-time approach, and it found that the force response is not particularly sensitive to changes in anyparameter