about heat and cold therapy. I've heard that you should just ice at first, make sure not to keep the ice on for too long, like 10-20 min at most, then wait until the area has regained normal temperature, then do it again. You should do it in intervals because if you put it on for too long, the body will respond by dialating the blood vessels leading to the area. Heat will do the same, so you should wait with heat until later in the treatment, but how long?
Also, one thing I've never quite understood. When you put ice on and the blood vessels constrict, won't that hinder the body's natural healing process?
I'll get to your 2nd question first, because it kind of addresses the previous. Ice constricts blood flow, that is correct. And it is also necessary when dealing with the majority of bruising/tearing type injuries (sprains/strains), because when you sprain or strain something, you've essentially torn tissue asunder allowing blood to flow and pool into places it's not supposed to, and when coupled with your bodies blood pressure, increased swelling and possible further tissue damage occurs. While heat aid in circulation necessary for tissue repair, it causes blood flow to increase to the targeted area, which can and will increase swelling, as the blood is no longer retained to capillary beds at the site of the swelling and injury, meaning that it is still spilling into the affected tissue.
Applying cold to the area prevents excessive swelling, and if the injury is treated quickly enough, and isn't anything beyond a moderate sprain/strain, can actually prevent some swelling altogether. And you are correct that you should apply cold in managed intervals. This allows for an organized constriction of blood flow, preventing any more swelling during the 15-20 minutes when cold is applied, but also allows for necessary circulation required for tissue repair (when taking a rest from cold application). The amount of cold application can vary by region and amount of injury/swelling, but at a minimum, you should be applying cold for at least 20 minutes every hour, and at most I'd say apply cold for 10 minutes on, 20 off, to prevent tissue damage due to freezing.
A good rule of thumb is to apply cold until swelling is gone, then apply heat for 20 minutes every hour in order to promote circulation and ease pain. For minor sprains/strains, swelling can last for 48 hours up to a week, For grade 2 and 3 strains/sprains, swelling and injury can last weeks to months (with most grade 3 injuries requiring surgical repair to the affected tissue). As long as there is swelling, I'd avoid heat therapy. I'd also avoid stretching at this point as well as you will warm the muscle and promote circulation, which should be put off until swelling receeds.
