In reply to Darrells comment that tattooing the muscle might upset it: You don't need to make any physical marks on the muscle to reconstruct its shape from photos. You can use light spots projected onto the surface instead. As the muscle moves the pattern of light spots will change but provided you take images from several directions at exactly the same time this shouldn't matter. There are well developed techniques for reconstructing the 3D shape from the photos (photogrammetry is the buzzword). I have a colleague who does this with mirrors for solar energy collectors and I recall him getting impressively good accuracy (something like 0.1% in all dimensions I think, but don't quote me on that). I can put you in touch with him if you like John.
Alternatively, I have heard of laser scanner machines that measure 3D shapes precisely. Regards, Will
