Specifications

128
reducing Lt0:
AnyMuscleModel2ELin Model2 = {
F0 = 200;
Lfbar = 0.3;
Lt0 = 0.3;
Epsilonbar = 0.05;
V0 = -0.3;
};
This reduction of the tendon length from 0.5 to 0.3 meters is very significant compared to the nominal
muscle fiber length of Lfbar = 0.3 m. Reducing the length of the tendon increases the length and thereby
the strength of the muscle:
The interdependency between the stretch of the tendon, the length of the muscle, and the strength of the
muscle is the origin of another approximation in the model: The system computes the changed length of the
muscle due to the stretching of the tendon, but this length change is not taken into account in the
computation of the muscle strength. Nevertheless, let us investigate how the stretch of the tendon
influences the muscle. We shall define an external load on the arm, which causes the tendon to stretch. But
before we change anything, let us just notice that the variation of muscle length, Lm, over the movement in
the absence of an external load is as shown below: