Why does my knee pop? Linked to an article explaining the muscle tug of war that my doctor once told me I have, and a short time of physical therapy would fix. Article has multiple exercises for the knees so I can get into races again.
5 Hip Stretches for Low Back Pain Prevention and Relief
Tight hip muscles can pull your low back or sacrum out of alignment. Try these great stretches to help alleviate: http://backandneck.about.com/od/Stretching-Exercises/ss/Hip-Stretching-Exercises-for-Back-Pain-Relief.htm