When I was in high school, the treatment for an injury was “Get him out of the game!” That was about it. When I got home after an injury, I poured boiling water into a large porcelain basin, and soaked the injury in hot water and Epsom salts.
I was a kind of gawky kid with weak ankles, and I can remember many a night when my mother would prepare the basin. I’d sit with my foot poised over it, steam welling up, and place the sole of my foot very gingerly on top of the water. Then when I finally felt brave enough I would lower it completely into the basin. Twenty minutes later I could pull it out. By that time, it had swelled to the size of a Buick, and was throbbing in pain. That was the collective wisdom of the medical community. We’ve come a long way since then.
We now know that the best treatment for a soft tissue injury, a sprain or strain or bruise, is ice, not heat. But why?
The theories behind icing an injury have changed over time. Getting an exact handle on what is happening physiologically is difficult. We can leave that to the researchers. We do know that ice, when properly applied can STOP swelling, STOP inflammation, and reduce pain. It is important to note that I said STOP, not reverse. That means ice should be applied IMMEDIATELY, because most of the swelling will occur within 5 minutes of the injury. It does no good to wait until you get home.
Stopping the swelling and inflammation means the player can return to full activity sooner. The less time spent favoring an injury, the better. Favoring an injury always runs the risk of some other body part being adversely affected.
So the answer to the question of why we ice is: To STOP swelling and inflammation, and reduce pain. But this only happens if we act quickly, in most cases within 5 minutes.