A number of previous posts have mention core weakness. I think there is something key in this. Last year I was in less than good shape (as a 53 yr. old) and had a number of "tweaks" in my back from hard falls, less than good form doing squats, running when tired, and finally pulling some pretty good G's on heelside turns. The result was a bulging disk in the L5 S1 joint which really bloomed during a trip out west with my son and my brother last year. I could stand, or I could sit, but moving from one position to the other was extremely painful. Like getting off the lift. Buckets of Advil, ice, and stretching if I could, kept things manageable. .Sometimes I would stand up, and without warning fall to my knees in pain. What fun. Come spring, one of the only things I could do without pain was ride my road bike. Must have been the stretched out position. I was prescribed Lyrica, which I think originally was developed for diabetics to calm the inflamed nerve endings they are prone to, but a side benefit was noticed for nerves irritated by disk mis-alignment. This helped, and things finally subsided enough that I started working on my core strength and balance by mid summer. Bosu balls and exercise balls were key. Most of my strength training was done with less weight and some kind of core challenge involved. I felt a bit like a sideshow in the gym doing upright rows, cable chops, and one legged squats with a bosu and so forth, but the pay off has been good core strength and balance. No pain this winter, and if I get myself off balance or hit some crap snow I usually can recover much more quickly and without straining something. I also did a lot of stretching and got some good massage when I could afford it. For what it's worth, it worked for me. Core strength and stretching. Aging sucks.
I rarely run angles higher than 55/50.