You may have abnormal biomechanics in your feet. Dorsiflexion of the big toe is not an uncommon foot complaint, and can be corrected with simple manipulation. Check out a local podiatrist or chiropractor that specializes in extremities. It'll make your knees and back feel good too.
A g-string is a bathing suit that certain women are qualified to wear. A thong is a type of sandal more commonly called a "flip-flop", another type of thong is the leather strap that Thor (the Norse god of thunder) suspended his hammer from.