In reply to alx:
> You achieve near same results by rolling the forearm with a broom stick, golf ball or hockey ball!
Maybe "near same" but not the same.
I've used both the methods you list and the armaid and, if the money is no problem / you are sufficiently chronically afflicted, the armaid is possibly worth the premium.
Whilst you can get a nice rolling massage with balls / broomsticks, I find the armaid to be much better for applying pressure deep into knots of muscle and right into the elbow joint. The pincer construction means that you can very firmly and specifically squeeze tender / tight spots whilst flexing / tensing the arm: for high pressure followed by a feeling of deep release (perhaps pasbury's allusions above aren't that far off the mark!). Daft looking and maybe overpriced (although that depends on your level of affliction, priorities, and income) but certainly not ineffective.
Not to say that I feel simple. improvised methods are always inferior though - I've not found a better self-help tool for shoulder / neck pain pain than a lacrosse ball!