Hi Kari,
I just sprained my back last Saturday so I started taking a liquid supplement containing Glucosamine/Chondroiton/MSM to help speed the healing. Besides being good for your joints, this stuff is also supposed to help your body build connective tissue.
I've never hurt my back before so this has been a frightning experience for me. I also like working out and lifting weights, so the gym is off limits until I am fully healed
This is also my first sprain, but it seems to be healing very quickly (I'll know for sure when I go back to school on Monday and sit in one of those old ergonomically designed desks

) I've also been seeing a good chiropractor since this happened. I am sure the adjustments and massages are increasing circulation to the injured area which is speeding up the healing as well, I am well pleased with the improvement.
As far as the vitamin C goes, I know it is necessary for the absorption/assimilation of minerals and other nutrients. Excess amounts of vitamin C that are consumed and not able to be used by the body bind to toxins, heavy metals, excess minerals, and other things in the bloodstream that do not belong in the body, which then is filtered by the kidneys into urine so it can be excreted from the body (so when you hear people say there is no point in taking large doses of "C" because you only "pee it out", that is partially true-- it is not without benefits). This is the reason why megadosing with vitamin C is suggested for many different causes. Regards.