If his problem is chronic back pain he should be referred to a chronic pain clinic where he would spend between 2 and 4 weeks (a fortnight for those still working) learning to adapt to and cope with his pain - increase his mobility and reduce any reliance on medication to only episodes of moderate to severe pain. I went to the INPUT Pain Unit at St.Thomas's a few years ago and this has kept me mobile and in work. The thing with chronic back pain is that it usually waxes and wanes, and you learn to adapt to that. I'm sure your half-brother could work if he wanted to. The problem in part is that he would probably be much better off on benefits than earning.