How long have you been at it, and what weights are we talking about? Delayed onset muscle soreness (DOMS) usually goes away after a couple weeks on the program, unless you have a hiatus. Tendonosis-type soreness is a different thing, but is more likely exposing form problems than volume issues. Arthritis has been known to improve with training.
The book is pretty clear about light warmups (bar only) so you may need to re-read (or buy the book) and consider Barbell Rx, as it suggests more light warmups for our demographic.