Static optimization result

[rajat das]

Hi
I am doing a Single limb stand (left leg) exercise where the participants first stance in double support and then single limb standing and then after some time double limb support. I am posting the muscle activation of "Tibialis Anterior Right" , where during the Single limb stand this particular muscle activation is almost zero. Is it possible or I am doing something wrong ?

[Thomas Uchida]

Do you have EMG or is there published data you can use to validate your results?
Also, you might check that you're interpreting the results correctly. You said in your post that the model is standing on its left leg but the screencap shows the model standing on its right leg. You also said that you've plotted the activation of the right tibialis anterior, but the title and filename of the plot suggest that the activation of the right tibialis posterior was plotted.

[rajat das]

Hi sorry for the error. However this is our experimnetal data. Where the subject stand on his left leg. However for tib_post_r muscle I am getting some flat activation during that single limb standing. Is this result is OK. I don't have EMG data.

[Thomas Uchida]

I'm still confused. If what you're saying is accurate, then something has gone wrong because your model is not standing on its left leg in the image. Regardless, the result may be reasonable, depending on the activity of the other muscles, how much passive force is being generated, whether coordinate limit forces are being generated, etc. Perhaps more importantly, whether the result is acceptable depends on your research question: what are you trying to study, and will your conclusions be sensitive to the activation of this muscle? Remember that "all models are wrong, but some are useful". To be sure that your model and simulation results are useful, you will need to develop a validation strategy. You may be interested in the following paper, which discusses these issues in detail and provides examples you may find helpful:

Hicks, J.L., et al. Is my model good enough? Best practices for verification and validation of musculoskeletal models and simulations of movement. ASME Journal of Biomechanical Engineering 137(2):020905, 2015. http://nmbl.stanford.edu/publications/pdf/Hicks2015.pdf