If you are like me you have aches and pains that just seem to come with the aging process. I found that lifting heavy all the time was really hard on my body. Especially bench presses and squats, tow of the more important lifts in my routine.
So I bit the bullet and went light! I dropped the bench press altogether. I went to dumbell flyes, using a weight I could get 15 reps out of. I use the cable rowing machine as a back exercise with pretty light level there too. Also the leg press with only 175-200 lbs on it.
The point of doing the 15 reps is to go slow and still get a good pump out of it. It has been shown that exercising to failure with light weights does as much for muscle as the heavy weights lower reps does.
SO why hurt yourself? If you are having joint and lower back pain, try this lighter routine and see what it can do for you.
Oh and don't skip the stretches before and after....a few minutes makes a world of difference.