Hi james, Thank you very much for your help. Ok, to let you better understand how the two different models look like, please see the attached picture. However I agree that the angular displacement of the segment would be similar in both cases (short and long muscles), but I don't understand why the ...

Hi everybody, I am studying and trying to understand how contact forces are implemented in Simbody, more particularly Hunt Crossley Contact Force implemented in HuntCrossleyForce.cpp, what I found is the the friction force is always dependent on the slip velocity, which means that friction force is ...

Hi Cosimo, Are you sure you are plotting the total fiber-force by calling CMC output "*_states.sto" file? Because usually "*_states.sto" files contain information about the state variables of your system (i.e. joint angles, muscle fiber lengths, muscle activation..), whereas "*_Kinematics_q.sto" con...

You are welcome.
However, If you set "MuscleAnalysis" in your .xml file, the power of muscle, the fiber active and passive powers, and the tendon power are all stored in separate output files.

Good luck with your research
Ali

Hi Rachel, Yes, this is correct. The tendon force is equal to the muscle fiber force along tendon (not the muscle fiber force), F_T=F_MaT. The difference between the two forces, muscle fiber force and muscle fiber force along tendon, is that the last one depends also on the pennation angle. F_MaT=F_...

Hi Rachel, Yes, in the output files you can have all the data you need. For example, In "*_Actuation_force.sto" file the muscle forces are stored, those force are the muscle fiber forces along tendon or the tendon forces (they are equal)... they are exactly why you plotted by OpenSim plot tool "tota...

Hi everybody, I have a basic question, I have to success in explaining the problem. When trying to run two similar simulations with different muscle sizes, each is made by one segment that rotate about z axis and two muscles (agonist and antagonist muscles), in both the tendon slack to optimal fiber...

Hi, I would like to start my simulation from a mechanical equilibrium of the whole system. To do so, I need to compute the the equilibrium values for states to set them as initial values of the simulation. I found this option in the FD setting documentation (<solve_for_equilibrium_for_auxiliary_stat...

Hi, I would like to plot the force-velocity curve and extract other values using scripting commands. I tried to used the MATLAB and GUI interfaces to access some data, I used printMuscleCurveToCSVFile (const std::string &path) in the ForceVelocityCurve method to print out the force velocity curve to...

Hi My name is Ali, and I am a PhD student in robotics. I have been reading the papers related to Thelen 2003 Muscle Model to understand better the algorithm of the activation and the musculotendon contraction dynamics. I have also been reading the papers related to CMC algorithm in order to understa...