the annular ligament, by which the head of the radius is bound to the radial notch of the ulna...prevents any separation of the two bones laterally.
As a result of the annular ligament, the proximal radioulnar joint and -- quite honestly -- the humeroulnar joint, the humeroradial joint is considered to be "limited." In other words, the humeroradial joint is typically considered only to be capable of taking part in flexion/extension of the elbow and lateral/medial rotation of the forearm.
However, although no internet/textbook search I've conducted mentions it, I'm wondering does the humeroradial joint allow any movements at all in the frontal plane (i.e., adduction/abduction)?
Here's a visual:
It seems unlikely, but at least a slight "jittering" seems possible.
Although just barely related, the knee (a hinge joint) comes to mind because of its somewhat unexpected (based on classification, not structure) ability to "slightly rotate" when unlocking.