Tee Shirts

I am looking for arm bands that you can wear under summertime t-shirts to hold up the post surgery flap between the elbow and shoulder.  Some kind of basic band, not a sleeve.  Any reccomendations?

I don't think I've seen anything commercially, but how about DIY? You can buy elastic by the yard at your local fabric store, and I imagine some of the flat, non-roll knit elastic meant for waistbands would do the trick. The standard size is 1.75" wide, though I'm fairly sure I've seen wider (maybe 3"?) sold on spools as well meant for making belts. You'd just need to overlap the ends by about 1", then run some very short stitches through the overlapped ends with heavy-weight or double-stranded thread by hand. :)