How long should icing be applied to an injury according to standard practice?

The standard practice for icing an injury suggests that applying ice for 20 minutes is optimal for reducing swelling and pain. This duration allows sufficient time for the cold to penetrate and effectively lower the tissue temperature, which helps constrict blood vessels, thereby minimizing inflammation and alleviating pain. The subsequent 20-minute break allows tissues to gradually return to their normal temperature and prevents potential ice burn or damage to the skin.

The other options offer varying durations that either do not allow enough time for effective cooling or provide excessive application periods that could lead to adverse effects. For example, shorter durations might not adequately reduce swelling, while longer durations could result in tissue damage or frostbite. Thus, the 20-minute on, 20-minute off cycle strikes a balance between providing therapeutic benefits and ensuring safety for the injured area.