Low Squats-Olympic Style

Good day gentlemen,
I have two questions concerning Olympic style training including all the secondary exercises and training for the sport and general athletic training.

The first question concerns squatting. (I really hope some of the coaches and trainers see this one and can post an answer as well perhaps). I love heavy lifting. I’m always trying to get my pulls, presses and intensity up. Oftentimes I go too heavy too soon and end up with injuries and whatnot and I’m sure this is something so many of you are familiar with.

  After reading a number of articles on injuries and recovery, one namely from Coach Thib about low squatting I realized that I had a huge amount of spinal flexion at the bottom of my squats. As soon as I got a little below parallel my lower back started to curve inwards. This is incredibly frustrating to me since my low squats, while ass-to-the-grass are in fact actually hurting me in the end and eating up my lower back. 

However, I love squats very much and would like to continue Olympic lifting at least to some degree and I need that perfect bottom position. I heard that it is possible to increase flexibility such that my spine will maintain proper position even in a low squat whether it is a front, back, or overhead variation. Can anyone please point me in the right direction?

  The second question is about a specific exercise I heard about and tried a couple of times. It is basically a front squat from the rack from the lowest position, like the second half of the squat and then back down. Would anyone familiar with this variation of the squat please give me some info about it...is it a good idea, bad idea, etc.

  Thank very much folks and I'm so very sorry for rambling so much. I appreciate all your help and your time and patience. Have a great day.

http://www.T-Nation.com/tmagnum/readTopic.do?id=2392837

Box squatting to a depth where your spine doesn’t round is usually the temporary solution.

In the meantime develop your hip mobility and perform drills to become aware of when your lumbar spine rounds.

Thanks a lot Iron, I appreciate all the help.