Currently in the process of creating a rig but the joints on the arms aren't behaving exactly how I want them.

As you see, they're quite bendy but I would like it to be a rigid bend, as I (tried) to show on the image. I understand it would be to do with painting on skin weights?
Any help on this would be appreciated

Thanks,
Tom
(EDIT: I believe this is the right section, sorry if that's not the case)