Headbanging Strategies for Autism/LD

Does anybody have any good strategies for adults with learning disabilities, autism or both in how to prevent head banging or methods of prevention?

My son who has severe autism and behaviours that challenge services, used to head bang consistently anything hard, eventually we managed to get him referred to ENT for ? sinusitis, he had a wash out and removal of his adenoids, and virtually stopped. We think it was his way of managing his head pain as a young child. His dad suffered from sinusitis too so, it was a process of elimination…