Heat Therapy
Injury type: Acute
Category: Lifestyle Options
Rating: Not effective
What is it?
Heat therapy involves the application of a heat causing agent to the body. Heat may be applied to the tissues directly by a heat pack or cream, or indirectly by a ray lamp. Tissue heating may also be caused by other forms of electrotherapy, but these are discussed separately.
How does it work?
The application of heat to a tissue such as muscle is thought to increase the blood flow to that area, possibly facilitating the healing process by delivering the required cells and nutrients. Heat may also increase the elasticity/extensibility of connective tissues, thus reducing muscle tightness and/or spasm. The sensation of heat within the tissues may distract the brain from pain sensations that might be coming from the same region (the so-called pain gate theory), thereby providing further pain relief.
Is it effective?
There is conflicting evidence on the use of heat therapy in the management of whiplash. A systematic review1 which updated evidence on passive physical modalities reported no new evidence associated with the effectiveness of heat therapy. Based on historical and current evidence base, it was recommended that heat therapy is ‘likely not helpful/ not worth considering’ as a management option for recent grade I-II whiplash. However, a rapid review2 synthesising evidence from highest level primary studies, systematic reviews, and well-conducted clinical practice guidelines reported that heat (and ice) may assist in reducing pain in the initial treatment of neck pain including whiplash. Multiple clinical practice guidelines3 for the management of whiplash also stated conflicting recommendations relevant to the use of heat (or cold) therapy, ranging from ‘recommended’ to ‘insufficient evidence’. When heat (or cold) therapy is included as part of multimodal care (along with manual therapy, exercise and psychological strategies), one randomised controlled trial included in a systematic review4 reported a statistically but non-clinically significant improvement in self-rated disability for recent grades I-III whiplash, compared with education.
Are there any disadvantages?
Care should always be used when applying heat to the body. It is imperative not to over heat the tissues as this may cause a burn or tissue damage. You should never lie directly on a heat pack, rather the heat pack should be placed on your body. Heat therapy should not be used in the first 48-72 hours after an injury as it can increase the amount of swelling in the area and exacerbate symptoms. People with altered sensation should not use heat therapy, and there are certain other conditions where heat therapy is not advisable. Seek advice from your doctor or treating therapist if unsure.
Where do you get it?
Heat therapy can come in various forms, and there are many different brands. Heat packs, creams and lamps are available via numerous retail outlets such as department stores, medical suppliers, pharmacies/chemists, or over the internet.
Recommendations
Based on currently available evidence, the use of heat therapy following whiplash injuries cannot be recommended due to conflicting scientific evidence. More research is required.