I get a lot of questions regarding how to use ice, and when to use ice, and how to use heat, and when to use heat, and they’re very different modalities, and their very different uses. They're not interchangeable at all.
If you're having an acute back problem or a very unstable back problem, you have to assume that there's a lot of pain or a change in your pain for the worse. You have to assume there's a lot of swelling, as well. Now, I'm not saying there's this visible swelling, like in the knee or when you bump your head, but there is swelling around the tissue, around the joint area.
So, the ice in this case is very, very, very helpful. It does two things. Number one, it starts to slow down the blood flow to the area. It's called a vasil constrictor. It constricts the blood vessels, which is not that great for healing, but it's really good at trying to promote the swelling problem, get the swelling out of there.
Remember, blood is carrying all of the nutrients, which is a good thing. But, it's blood. It's a fluid and you want to rid the area in the first step in the recovery. And, that will enable you to move on to the second and third phases of the recovery, which is part of the modeling and repair phases.
The other problem or the other thing the ice does is by reducing the swelling. The swelling is pressing up against all the pain receptors, so if you can get the swelling out of there, there's going to be less pressure on those pain receptors. So, that will make the pain hurt less. So for two reasons really, you're going to use ice in the acute phase.
Once you’ve returned to function and you're in less pain, and you're more mobile, and you're having a better go of it, that's when you can, sort of , use the heat modality to, sort of, help with the soothing muscles. The heat will promote blood to the area. A vasil dilator, it's called. So, it can help with the last two phases of your healing.
In either case, whether you're using ice or heat, you're thinking 15 to 20 minute intervals with the modality. It's never recommended to put it right on your skin. You can really irritate your skin, hot or cold. And by and large, if you're not seeking a physical therapist's advice and you're using some of the general knowledge, you're going to want to stay away from the heat, by and large, for the first 3 days after injury. Certainly, within the first 7 to 10 days after injury, it can be recommended depending on how bad the pain is.