Yeah. Instead of having joints in the sense of separate pieces of plastic put together, the Jem dolls' arms and legs bend through something inside the limb...it clicks into place (three clicks to bend completely and three clicks to straighten). But this often wears out, it's quite common to find dolls with one or more limb that will no longer hold a pose.
Hands can also break...but they're not too bad unless the doll is Mexican. Mexican Jem hands break pretty much if you look at them wrong :/