ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

figure 2, we can determine the nodes voltage.
i_muscle = i_Na + i_si + i_K2 + i_x1 + i_x2 + i_qr!;
Figure 2: Schematic model for excitable membrane of muscle[20]
Generally in this research, an electrical stimulation in the synapse location is our input
according to [20] and the mechanical behavior of muscle is the output in order to show
the muscle behavior.
4. RESULTS AND DISCUSSIONS
It was shown that the proposed muscle model can be used to predict conceptually force
production properties and deformations in human muscles. Regarding the simulation, it
can be said that, at first force producing elements (Hill model) receive the potential
which stimulates the muscle, and then according to that excitation, a specified
contractile force is produced in the contractile elements. This force wants to shorten the
muscle but connections between that muscle fiber to adjacent fibers resist from this
shortening. So muscle fiber distributes its contraction between other adjacent fibers.
Finally new length of muscle is an interaction among muscle fibers in model.
As illustrated in figure 3 when the stimulation reaches to a cell, its displacement
increases and after that because of contraction distribution between adjacent fibers,
displacement decreases till it reaches to equilibrium with other fibers and at this time
there is no shortening. As a result we can say that even if one fiber stimulates, whole
muscle will be influenced by that excitation.
Fig 1: x displacement vs. time for an arbitrary node