Squat Question - Bar Slipping

I squat with the bar fairly low. Occasionally, and it seems like it is happening a lot lately, the bar will slip further down the last or close to the last rep. I was talking to a a guy I lift with occasionally about it. He said, for him, that is an indicator that he is falling forward and using his back to lift.

I’d like to think I have good form and I have it checked periodically. I am not opposed to the idea that this is a cause as falling forward and using my back has been a problem in the past. It hasn’t been, I think, lately. So my basic question is if the bar is slipping down, is that a solid indicator of me using my back?

Your question confuses me. Just chalk your back if the bar is slipping.

You might just not have a big enough shelf to stop the bar from sliding…Get a bigger upper back

I had to think about this one, as it shouldn’t happen, if you’re keeping your upper back tight. And that was it. I’ll bet you’re letting your shoulders come forward as you tire at the end of the set, losing your shelf whereupon the bar starts moving down.

Added to that, if you don’t keep the back tight, your upper back will tend to round, which will take you out of position due to the changed leverage. If it goes far enough you’ll tend to lean forward more and that’ll cause you to use your back to lift.

Just a theory, though.

Alridght skid, let me see I have got this. You are saying my upper body isn’t remaining tight, not the lower. That is starting to make since I am not pitching forward like my lower back was weak. But why would this start all of a sudden? I’ll focus on it today if my quad doesn’t tear completely apart.