Despite manager Avram Grant's insistence the Hammers play 'good football', the club are still five points short of safety after just one win in 13 games.
Obinna, who has yet to score in 10 top-flight appearances since joining West Ham on a season-long loan from Inter Milan, told WHUTV: 'We have to back ourselves, speak to ourselves and try to improve.
Time to roll the sleeves up: Obinna is demanding a survival push from West Ham
'We can all say that we play good football, but when you play good football and you don't win, sometimes it doesn't work. Sometimes you have to play badly and win and I believe our time is coming.
'Sometimes you are lucky and sometimes you have to play simple to be able to score. When things are like this, it's getting bad but we have to show that our heads are high, we are more united and if we speak to ourselves mentally we will win games and we will be OK.'
Nigeria international Obinna, 23, also thinks the Hammers have a mental barrier to overcome in their fight for survival.
The club have been in the bottom three all season and have only been higher than 20th place for three weeks of Grant's time in charge.
Obinna said: 'I've never been down at the bottom for so long in my career. This is the first time I've been in a position like this, being at the bottom of the table for quite some weeks.
'I don't know what's wrong, but we'll just have to go back and speak more to ourselves. Now, I think it is mental stuff. It is no more about playing, playing, playing - it's about mental stuff and we just have to psyche ourselves up, speak more to ourselves, be more united and we're definitely going to get out of this place.'
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