It's exactly like a walker, except with the added danger of hip-destroying impact.
The idea of creating playgrounds tailor-made for old bodies began in China, then spread to Japan, where, if reports are to be believed, no children have been born since 1988. With fewer and fewer children, and old Asians bursting at the seams, local governments began disassembling children's playground equipment and replacing them with equipment designed for the elderly. It would have been sad if there'd been any kids around to whine about it.
It's like a reverse Children of the Corn without all that corn.
Today there are senior playgrounds in Germany, the U.K., Canada and Nuremberg, and most of them prohibit children from joining in the fun. One even has this totally serious sign at the entrance: