Review on Bongers Bongers Percussion Massager, Purple Pair - 11.4 Oz by Laura Crawford

They are very effective in speeding the healing of sore muscles compared to simply stretching or rubbing the muscles. It's good that it hurts and I feel relieved after using it. I tried it on my head just for fun and wow it was unexpected to feel the tension I was holding there and next time feel the difference (no tension) in the same area. If the area isn't tight or sore, it's just like hitting a ball in that area lol. I find it best to use in an area that needs it.