This article is from the Hardgainer Bodybuilding & Weightlifting FAQ, by Frank J. Kelly and Craig R. Sadler with numerous contributions by others.
When using very heavy weights (above double bodyweight) certain
people have reported effects resulting from compression of the
spine. This can be alleviated to some degree by having strong
shoulders, traps and and overall back muscles, and by
performing hanging from a bar by your hands to help alleviate
any stress. However before reaching double-bodyweight squats this
should not pose any problem.
 
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