I'm still a noob to lifting, just starting up again after getting all healed up. I had a surgery to remove melanoma from my back this summer, which severed lots of nerves. I can't really feel my triceps. I can tell they're there and can FEEL when I touch them, but it is a very numb and empty feeling. I think I feel the skin, but not anything inside. Could this be effecting my dumbbell press / bench? When I do dumbbell press, my left arm can't put up as many reps as my right. When I do barbell curls, my left arm can pull up its share of the weight, but my right can't. WTF? Should I start isolating these muscles to make them more equal? I.e. do more curls with one arm and maybe tri-extensions with the other? Could this be related to the numbness I'm feeling?