wogihao

I had a similar problem once, when i overhead lift it used to look like i would need a spinal board after the set. its because i used a belt so much it weakened the core suport muscles that you need if you want to get a respectable overhead press.

I would agree with whats been said your probably compounding this by doing a push press instead of a military press and leaning back.

the best way to make sure your back is straight is to keep your chin down and your heals togeather (thus the name military press because its the same as when your on the parade ground.)

oh and as a side note, do your self a favour and use a olympic bar, the small bars are crap as the colars do not rotate and it makes stuff like cleans very hard. Also unless your a midget your find your hand postioning is not good when racking anything bar a olympic bar as its harder to balance.