AIBU to think that if you're cornered and hit someone, you're ok (in law)?

[JetTail]

Is it justifiable?
As a means to escape?

It depends on the circumstances. Every situation will be unique.

Google english law on self defence.

What happened, if this was in self defence you could speak to the police to report you were attacked or threatened.

As an act of self defense, yes, but like previous poster has said, every circumstance will be different.

Depends on self defence definition really. Also the force has to be proportionate - ie if someone smacked you with a hand you can't then go and smack them with a hammer that would be considered disproportionate. Also why anyone with any martial arts background or boxing etc tend to get more serious sentences as it's not considered a "fair fight"

Need more information to be able to decide because someone blocking your way isn’t an automatic reason to hit them

You can use necessary and reasonable force to defend yourself, in any situation. But there is no situation that gives you a green light to use whatever force you want. The circumstances at the time would have to be considered, e.g. could you have walked away? Could you just have pushed them away? Did you only hit them once, or multiple times? Etc.

Why do you assume OP is in England?

If they are restraining you I think yes if they have you backed into a corner I think your expected to ask them to move and make a reasonable attempt to leave without violence for example

Exh backed me into a corner I asked him to move I wanted to leave he said I'm not stopping you so I moved to duck under his arm he deliberately blocked me but as I was already moving I brushed past his arm he flipped out and actually told the police I assaulted him by "shoving" him the police said what I did was not ideal and I should have sought another solution but as there was no harm done they would let it pass this time

I suppose is it reasonable to incapacitate your captor in order to flee?

No point speculating on this anymore until OP comes back with more context

I couldn't have walked away as they blocked my exit. I tried to push past them but they were at least double my size. I didn't hit try anything else as I was afraid of repercussions so I was held hostage for about 3 hours.

Its impossible to say without knowing the full circumstances. There are so many variables.

If you can think of it like a security guard or something blocking you in somewhere. The laws that I've googled tells me they have no power unless they think you may have committed a crime (never a question in this case) in which case they can make a sort of citizens arrest. But they simply held me for about 4 hours.

I am in England.

Still not really enough context. Tantalising hints by using words like "captive" and "flee" but I just have a feeling you are trying to build up and draw people in without setting your situation out properly

and I have no idea how long as you may have gathered. I'm trying to get a timetable based on texts and phonecalls made before and after. Anything between 3 and 5 hours I would say.

But they simply held me for about 4 hours

WHY? Not trying to excuse it just want done background* *

The long and the short answer is that I do not know why.

I'm afraid that I don't know why either.

Maybe set out the details on the Legal Matters board?

As a general rule a security guard would not stop you from leaving for 4 or 5 hours. Neither would they stop you without reason. And they would most likely explain why they are doing so.

Well if they are so much bigger than you it sounds like any attempt to take them on physically might not work or might result in you being hurt.
If you are safe now could you go to the police and report what happened. Refuse to be in this person's vompsny again. Alert other family members to the incident. Are any of these options?

The long and the short answer is that I do not know why.

You must have some inkling?

If someone, as part of their job, is legitimately detaining you (for whatever reason) then no, you shouldn't be fighting back, so you won't have a leg to stand on.