There are 61 million runners in the US. The injury rate is between 37%-54%. These injuries consist of shin splints, ankle sprains, hamstring pulls, calf strains, hips and the list goes on. The Stinger can recoup your entire body from all of these injuries. Just place the Stinger in the freezer for two hours staying cold up to six. The Stinger can be used with or without the handle. You can throw away your lacrosse ball and foam roller because the Stinger recoups the entire body.