Cryotherapy and inflammation: evidence beyond the cardinal signs

Background: Cryotherapy is one of the most popular electro-physical agents used to 'treat' acute inflammation after a soft tissue injury. Much of the clinical rationale for this is based on anecdotal reports, with most clinicians accepting that cryotherapy has an 'anti' inflammatory effect after injury. There have been a number of recent advances towards improving our understanding of the inflammatory process after soft tissue injury. Objectives: To review the rationale for cryotherapy intervention in the acute phases of soft tissue injury, whilst considering physiological, cellular and molecular models of inflammation. Methods: Qualitative review of recent evidence. Results: Research is restricted to animal models, applying various forms of cryotherapy after induced soft tissue injury. Outcomes focus on the effect that cooling has on key physiological, biochemical and molecular inflammatory events including: secondary cell death, white blood cell behaviour, apoptosis, blood flow and oedema formation. Conclusion: Cryotherapy can have an influence on key inflammatory events at a cellular and physiological level after an acute soft tissue injury. However, the relative benefits of these effects have yet to be fully elucidated and it is difficult to contextualize within a human model. It is important to continue to update our rationale for applying common electro-physical agents such as cryotherapy after acute soft tissue injury, based on contemporary models of inflammation.