Osteophytic lipping

I have moderate osteophytic lipping on the vertebral margins at L2/3 and L3/4 levels

This has probably occurred because of 1) a sedentary work-style, sitting before a computer screen, and 2) being over-weight.

Exercise is important, but here is the quandary. I cannot go walking, because it hurts my lower back. Swimming and other low impact exercises may be the answer (particular kung fu or tai chi programs)