cryotherapy
/ KRY-oh-ther-uh-pee /
When you twist an ankle, the first thing most people reach for is a bag of ice. There is good reason: cooling a fresh injury can ease pain and limit swelling. Cryotherapy is the clinical use of cold — ice packs, cold packs, ice massage, cold-water immersion, and quick-evaporating vapocoolant sprays — to achieve those effects on purpose.
Cold does roughly the opposite of heat. It causes vasoconstriction (small blood vessels narrow), which reduces blood flow and helps limit bleeding and swelling in a fresh injury. It slows nerve signalling, producing numbness and pain relief, and it lowers the metabolic demand of injured tissue. A typical application — for instance an ice pack wrapped in a thin towel for around fifteen to twenty minutes — also tends to calm muscle spasm. Vapocoolant spray gives a brief, intense surface chill, sometimes used to numb a spot for a moment or as 'spray and stretch' for trigger points.
Cold is the classic choice for the first day or two after an acute injury, as part of the old RICE idea (rest, ice, compression, elevation). But its evidence is more modest than its popularity suggests: cold reliably reduces pain in the short term, while its effect on the speed of actual healing is uncertain, and prolonged icing may even slow some repair processes. Cold must be applied with a barrier and time limit to avoid frostbite, and it is avoided in people with poor circulation, cold hypersensitivity, or numb skin who cannot feel it becoming too cold.
Right after a player rolls an ankle, the trainer wraps an ice pack in a thin towel and applies it for fifteen minutes to ease pain and limit the swelling that would otherwise build up overnight.
Cold for the fresh injury; always with a barrier and a time limit.
Ice reliably reduces short-term pain, but the popular belief that it speeds healing is not well supported, and prolonged icing may even hinder some repair processes.