So VAR rules are that any part of your body that can score a goal is offside and Salah has a couple of offsides given against him because his shoulder is offside but then Sakho scores with his shoulder and it's ruled out for handball, honestly this VAR system if it wasn't so laughable you would think it was corrupt.
It's an absolute shambles and is turning a few people I know away from football due to the way it's making stuff up as it goes along.
Top of your shoulder is fine, front is handball so you could technically be offside if you're shoulder is off.