As someone who's considering using system dynamics to model musculoskeletal systems, I'd be interested in your experiences. Could you pm me your email?
I work at the cellular/molecular scales in a computational biology program; musculoskeletal stuff can often find a home in bioengineering departments. Not sure how much insight I can offer, but feel free to shoot me an email, my contact info is here: http://www.pitt.edu/~donovanr/
Theoretical biology seems to be the black sheep of both the wet-lab biology and simulation communities, a situation that I wish were different, but honestly it can be difficult to make a compelling case for the role/yield of theory in biology beyond a few simple models and natural selection etc.
It's frustrating, because I think the most fruitful area we can work on is developing a better understanding / mathematical formulation of the incredibly high dimensional, nonlinear, stochastic spaces that biological systems live in, but it's difficult to see the way forward because no on (that I know of) is putting time into thinking about it.