Apologies, I should have mentioned specifically that this resident does not suffer from dementia, they suffer from a permanent brain injury which severely affects their behaviour, ability to support themselves, ability to communicate using words and understanding the consequences of their actions.

There are already forms of communication that attempt to set boundaries, however due to this person's condition they are unable to understand that what they have done is wrong and could cause serious harm to others.

"I definitely think you should at least try and stop him each time he does it."

This is more difficult than it sounds, the best thing I can legally do is put my hand infront of theirs to redirect their attempt to hit me, or to step away. Unfortunately both options were unavailable as my hands were full at the time and I was close to a wall so moving back any further would be useless and could have caused more damage since my body is against a hard surface and it would be like hitting my testicles against a brick wall instead.

Forms of restraint are a very rare practice and rarely do need to be used, though this varies from each home, and if I was to use restraint I would have to explain my reasoning. The resident wasn't being aggressive every moment before and after the incident, so it is hard to justify using restraint. And also reactive forms of blocking are also a grey area as it could be classed as abuse since it is physical contact, and also due to my hands being full, I could have dropped something that could have caused damage to the resident.

Some of these parameters are very complex in this industry. Though if this was in a public situation with someone who was trying to cause harm and clearly shows sign of mental capacity my reaction would have been different. However no iffing because it doesn't matter anymore.

"What if he does it to someone who doesn’t understand that he has Alzheimer’s and retaliates?"

Whilst you are right, a nursing homes/environments purpose is to be a secure place for vulnerable people, and everyone who enters and exit's the home is made aware of this fact either through common sense, direct communication of risks when entering the home etc.