When a minifigure is new, the joints where its legs joins its hips is relatively stiff. However, when a minifig gets old and has been used a lot, this joint can get very loose leaving its legs very floppy. Why does this happen? Is there a risk-free way to re-tighten this joint?
I would try pulling off the legs and dropping a tiny, tiny amount of plastic glue on the hinge, smooth it out and let it dry, then put the leg back on. It should provide enough friction to the leg again so they aren't so loose.