62, if you are having problems with bending at the back, then your hip flexors are to tight. Most people don't even know how important hip flexors are to the squat. If your hip flexors are to tight, then your waist will bend foward on the way down. This will cause you to use to much back, therefore lowering your ability to use higer weights. If you would like to loosen them, DO NOT do goodmornings, they will tighten the hip flexors up. Now that we know the problem lets take care of it. In order to loosen up the hip flexors, you must streach them daily, 2 times a day. Streach them by using a slightly extended foward lung, while raising the opposite hand high in the air, reaching back as far as possible keeping shoulders square. Repeat for other side. Most of all keep weight on heels, look up at ceiling and sit back as if to sit on the toilet. Also think about pushing the hips foward on the way up. I hope this helps you get to where you want to be.