I was arm wrestling, ever since then if i hold something with palm facing up i get a lot of pain in the inner side of wrist ..smallest finger side...

Post-exercise: Post-exercise inflammation and swelling of muscle fibers and/or connective tissue. The symptoms include muscle stiffness, palpable tenderness, and pain with active muscle contractions. Moist heat, rest, muscle stretching and aleve (naproxen) otc will eliminate the problem. Rec.: if the condition is persist over a week, see your doctor.