Cryotherapy, also known as ice application, is the simplest and oldest way to treat injuries. Its worldwide use spread because of its effectiveness, convenience, low cost and ease of transportation. Ice is believed to control pain by instigating local anaesthesia. It also decreases oedema, nerve conduction velocities, cellular metabolism and local blood flow. The effect of the cryotherapy depends on the method, the duration, temperature of the ice and the depth of the subcutaneous fat. 
The most common method of cryotherapy is the use of ice packs. There are different types of ice used in ice packs. The most common types are ice packs made with cubed, crushed and wetted ice. It was discovered that wetted ice is better to lower surface temperature during treatment and maintaining the lower temperature during recovery. It is also more effective in lowering the intramuscular temperature during treatment.
A cooling effect can also be produced by icing spray for a similar effect.
More recently whole body cryotherapy has become popular for athletes, to help aid recover, as well as in persistent pain patients such as rheumatological conditions. More research is needed to understand the effect on the body and its relation to pain.
- Acute soft tissue injuries e.g. ankle sprain, muscular strain
- Post orthopaedic surgery e.g. TKR, ACL reconstruction, arthroscopic shoulder surgery.
- Acute sports injuries
- Pain relief
- Swelling reduction
- Decreased surface temperature
- Effective on a wide range of soft tissue injuries
- Little evidence regarding duration and frequency of treatment to be effective
- Compression has been shown to be more effective post operatively
- In rare cases bradycardia and frostbite symptoms have been observed. 
- Some more advanced cryotherapy devices can reduce range of movement following TKR due to immobilisation of the joint. 
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