A man will be imprisoned in a room with a door that's unlocked and opens inwards; as long as it does not occur to him to pull rather than push.
For what its worth:
This is a basic video explaining anatomical descriptive language and directions
its used to help orient knowlege of anatomy eg you can describe organs and structures in relation to each other eg as ventral to the spine (eg the aorta is ventral or anterior when compared to the spine, its closer to the front of your body)
but your back is part of the dorsal surface of your body. Anything behind your back eg the wall, chair etc must be further in the dorsal direction. Anything in front of your back is not 'behind' your back, it is more ventral, or forward facing.
I think you are mixing up the anatomic issue of it being a structure 'your back' with the idea of direction
This is the reason why the anatomic terms and directions explanined in the video are used. Very often the words used in (in English) mean so many differing things that its very difficult to describe things and their relationships precisely and clearly when you need to, as the various idiosyncratic interpretations here show.
Back is a great example of it
eg as a noun its specifically the rear surface of the torso (but not the legs, head, buttocks) although people refer to all of this as the back of their body (or back side, which also has a double meaning)
or it can mean the posterior part of something, from the point of view of an observer
but it can be a verb - eg to 'back someone' or support them, to move backwards (he backed into a corner)
or an adverb meaning the past (back in 1953) or the idea of return (I will get back to you) or move to an earlier state (they tidied everything back to its cupboard)and can be used to refer to relative positions eg 'the house backs onto our garden'
Next challenge! Can you now or have you ever been able to clearly differentiate your gluteal region from your olecranon?