Don't know if you'd be willing to try this, but it may be something weird to check out.
Go buy some rollerblade gloves. They have solid, angled plastic at the palms(you'd have to see them to understand). My buddy chipped a small bone near his wrist and I bought him a pair of these. The plastic diverted the pressure far enough away from the damaged area so that he could press. I wouldn't go real heavy with them, but they may be something to look into assuming that your bruise is on the meat(heal) of your palm.