@roger,
The few broken legs I could see were crushed flat on the road and shattered. From what I could tell, they were broken off right up to where they are attached to the body, not at a joint or two up from the ends. I doubt the crab would be cooperative enough to come out of the shell and allow me to glue them back on. Even if I could, they would only be stiff, immobile, dead legs to drag around.
Regarding spiders on Okinawa, I do not handle them -- not because they are poisonous (most are only slightly so, though we do have a "Yellow Widow" which is the poisonous Okinawan equivalent of the Black Widow) but because human handling of most spiders injure or damage the spider's legs. They are quite delicate and the pads on the tips of the legs are extremely sensitive. If I find one in an inappropriate place (i.e., in my home where the cats will only "play" with it until it's dead), I catch it in a net or carefully in a tissue, and put it out in the garden in a shady area.
I was once told by a SUNY entomologist that human skin oil harms the nerve endings on the delicate padding on the tips of the legs of many insects and spiders. It seems it actually hurts them to handle them. He theorized that this may be why a black widow spider bites "for no reason" if it crawls on you -- it may feel a burning sensation as its "feet" touch the skin, and bites at the cause of the pain (like most creatures will). Same for bees and other stinging insects -- they feel pain upon touching you (landing accidentally or to protect a nest) and take action against the cause of the pain.
Of course, some insects are better protected against this problem, like tarantulas and some beetles, etc.
By the way, we have some fairly big spiders here that make the classic circular net-type webs. These are "Banana Spiders" because of their size and body shape.
Want to see one? Go here:
http://navywifeadventures.blogspot.jp/2011/06/dumb-americans-guide-to-living-on_12.html
this is a pretty good blog and if you scroll down, you will find something about fish, snakes, hermit crabs, and about half-way down the page, banana spiders. And yes -- the body alone is frequently 3 inches long (sometimes 5 -- we have them in my backyard!).
Only an hour left here at school, then home to see what I can do for the little patient in my backpack...