Video
Stop Collapsing In The Clean





There are several possible reasons for collapsing when receiving cleans—far more than simply not having a strong enough trunk.
 
As a basic diagnostic, if you’re able to properly front squat with a quick descent and a bounce a weight that causes you to collapse in a clean, the issue is not one of strength or mobility primarily.

The quick take is that anything that negatively affects balance, achieving an ideal front squat position, or staying connected to the bar is likely to cause collapsing.
 
The first possibility is simply not bracing adequately in the lift overall, or at least while receiving the bar. Your trunk needs to be pressurized with air and braced forcefully from the start of the pull until you’re finished standing from the squat, and should be braced even harder as you receive the bar and sit into the bottom in preparation for the greatest force your trunk will have to resist in the lift.
 
Next is allowing the bar to crash down into the rack rather than staying connected and meeting the bar in the turnover—this multiplies the downward force of the bar and may exceed the ability of even a strong trunk to resist collapse.
 
Being imbalanced forward in the pull will mean forward momentum on the bar that can both result in it being too far forward in the rack position, and the body leaning forward into it and losing the structure necessary to support the weight. Being too far back in the pull can also cause collapsing as the body will round forward in the squat to try to re-establish balance over the feet.
 
Leaving the bar forward instead of bringing it back in the turnover, and leaning the chest forward to receive the bar, also reduces the integrity of the structure.
 
A poor rack position in which the shoulders are not actively pushed forward and up, and the bar is too far forward, even with correct balance and meeting the bar well in the turnover, also makes collapse likely.
 
The simplest way to look at correction is to put your body in the perfect front squat position and make the bar meet you there.