Please see attached a conference abstract that explains different options and their effects in more detail.

Hi, I want to use OpenSim to determine joint moments (and later on also muscle forces) during running using the Catelli model. The calculated joint moments for the knee and ankle do however not completely match the literature (see attached file). I have tried a lot of things to figure out what is go...

Hi Axel,

I managed to obtain muscle fiber lenghts using dynamic optimizaton. For the MTU length, it might help to open the generated file in excel and plot the MTU length. THis did help me in the past.

I guess it depends what you want to use the model for exactly. But the Catelli model could be useful as it has optimized muscle-tendon units paths with large knee and hip range of motions that occur during sprinting

Thanks all for your replies. In response to Michael: It is a dynamic contraction involving slow concentric-eccentric muscle fascicle behavior. Since the movements are relatively slow, I want to use SO as I think the rigid tendon assumption is reasonable. However, to check this assumption I would lik...

Hi, To 'validate' the muscle forces determined with static optimization, I would like to compare the length changes of the muscle fiber as estimated by static optimization to the muscle fascicle length changes I measured using B-mode ultrasound. When I use the muscle analysis tool the fiber lengths ...

I just found out what caused the issue. The name I gave to the joint was the same as the name I gave to the body. When I changed this, the topology view also was correct.

Hi, As explained in another post, I modeled a barbell by making two bodies that I attached to each hand with a custom joint. When I view the bodies/joints in the topology view they do not look correct as can be seen in the attached screenshot. Does anyone have any suggestions why this may occur? Or ...

Hi, I am comparing joint moments/muscle forces of different strength training exercises. For some exercises, the subject held a barbell in the hands, and the barbell contained three markers (on the center and at each end). Initially, I made one body representing the barbell and tried to connect it w...

Hi, Recent research found that slack can be present in both the fascicles and tendon/aponeurosis of the muscle-tendon unit and that the length at which slack is taken up can differ between both. I’m very interested in modelling the effects of slack on muscle fibre length changes during locomotion. F...