In an acute injury (the first 24-48 hours) ice is the best treatment. It reduces swelling and inflammation, reduces pain and decreases metabolism of cells so they don’t need more oxygen than is available to them thereby creating less damaged tissue for the body to repair. In this stage of an injury it is often crucial that the injured area be immobilized, even after icing.

However, once the acute stage has passed, ice and movement together can be a very effective treatment for injured muscles. Movement is essential to the healing process. Movement allows the new forming tissue to remain
pliable and healthy while keeping abnormal scar tissue from forming. The
icing numbs the pain so that this movement can occur.

In order to benefit from ice you must use it correctly. Avoid putting ice directly on the skin, wrap the ice or ice pack in a heavy towel or plastic bag then
apply. Chill the injured area for about 6 to 20 minutes, or until it gets numb (icing for more than 20 minutes may damage skin and nerves). Then begin to move the injured area. Start with small movements and gradually increase your range of motion. (Remember to move gently, since the tissue is numb you cannot feel it if you over-extend the area.) When the numbness wears off, apply the ice and repeat the entire process. It is recommended that you ice in this way at least 3 times a day. Ice is contraindicated for someone with circulatory insufficiencies, Raynaud’s Disease, or cold allergies.

“It is the movement part of the ice therapy that makes it so effective.
Athletic trainers who use ice and movement report that athletes who might have been out for the season can return to the field within one or two weeks after injury.” Excerpted from Listen to Your Pain by Ben E. Benjamin, Ph.D.