Here is an exercise you can do, using an inexpensive halloween skeleton from Dollar Tree, and several packs of sugru.
Incidentally, it looks like a college course (feets of clay) has taken up this approach to studying anatomy. (I like to imagine that this instructable inspired it.)
Step 1: Materials
two orange packs
one blue pack
one green pack
one black pack
one plastic halloween skeleton from the Dollar Store
4 for $1.00
Step 2: Sugru
Sugru cures relatively quickly. Working time may be two hours at the most. 30 minutes is the recommended amount of time, but I found it could be worked longer. So, for this reason, it may help to prepare the individual muscles in advance. The guide drawing below gives an approximation of the amount of sugru needed for each muscle. Assume the pieces are very flat - 1mm thick or so.
Sculpting with sugru straight out of the package is a bit like sculpting with chewing gum. Though as it starts to cure more, it becomes more like sculpey, which is good. It grabs onto itself very well so you have to not only work quickly, but once you lay something down, it is very difficult to pull it back up or manipulate it further without manipulating the layers underneath.
The great part about it is not having to bake the skeleton, as you would with sculpey. These skeletons cannot withstand even 150 degrees of temperature I found out early on in experimenting with sculpey
Step 3: Muscles of the Upper Leg
Step 4: Muscles of the Upper Leg Back View
Step 5: Muscles of the Lower Leg, Back View
Step 6: Muscles of the Torso and Upper Arm
Step 7: Muscles of the Torso Back View
Step 8: Muscles of the Forearm
Step 9: Muscles of the Forearm Back View
Step 10: Neck Muscles
Step 11: Finished
Hope you find this sort of useful as I did.