Bone building for the spine using weight exercises

Strengthening the spine using weight exercises is not that difficult.  However, it's important to use the correct form as well as the correct weight.  The idea is to develop form using a lighter weight but need to work up to a heavy weight in order to encourage bone growth.  The general guideline is to work up to a weight that allows 5-8 reps.  Doing heavy weight exercises 2-3 times a week has been shown to be enough to encourage bone growth over 6-12 months.

1) Weight lifting to prevent osteoporosis, 6 min
Importance of stacking the skeleton

2) Osteoporosis Exercises for Spine Strength and Posture - Australia, 9 min

Working on the middle of the back