Contrast bath therapy is a physical therapy treatment in which all or part of the body is immersed first in hot water, then in ice water, and then the procedure of alternating hot and cold is repeated several times. The contrast bath can help improve circulation around your injured tissue.
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| Hydrotherapy |
This is one of many whirlpool treatments physical therapists use to help decrease pain and muscle spasm, increase range of motion and strength, and improve functional mobility.
Goals of Treatment
If your physical therapist chooses to use a contrast bath for the treatment of your injury, the goals of treatment will most likely include:
- Decreased pain
- Decreased swelling
- Controlled inflammation
- Improved mobility
Be sure to ask your physical therapist the specific goals that are to be achieved by using the contrast bath so you know what to expect.
Injuries Treated
Injuries that benefit from contrast bath treatments are those that cause swelling and pain around soft tissue and the joints of the body.2 These injuries include, but are not limited to:
- Ankle and leg fractures
- Plantar fasciitis
- Achilles tendinitis
- Upper extremity fractures
- Hand and finger arthritis
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| Contrast Bath Hydrotherapy |
What Equipment is Needed?
- Two containers, buckets or sinks large enough to accommodate the body part to be treated
- Thermometer
- Towels (for drying and to put under the basins)
- Cold compress for the head (cold washcloths)
- Pitcher to remove and add hot water
- Means for heating water if not near a tub or sink
- Ice for cold compress and cold bath
Contrast Bath Therapy Application
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| Contrast Bath Hydrotherapy |
- Fill two tubs, large buckets or a double sink that you can fit your injured limb into
- Fill one with hot water (98 – 110 °F)
- Fill the other one with cold water (45 – 70 °F)
- Make sure you use a thermometer to verify the temperatures throughout the entire treatment
- If swelling is present, keep the temperature below 102 °F and keep your limb in the hot tub for a shorter duration
- If a joint is swollen and hot ONLY use cold; never heat
- Soak the affected area
- Start in the hot water for three to four (3 – 4) minutes
- Switch immediately to soaking in the cold water for one (1) minute
- If the cold water is not tolerated for the full minute, place it back in the hot water for three to four (3 – 4) minutes then return it to the cold water for as long as tolerated up to one (1) minute
- Always start with the hot water and end with the cold water, except:
- Rheumatoid Arthritis – end in the hot water and dry the area thoroughly
- The joint is swollen and hot, then only use cold water
- Repeat the above steps three to four (3 – 4) more times (about 20 minutes)
- More hot water may need to be added to maintain the right temperature for the “hot bath” (it might decrease from switching back and forth between the hot and cold water)
- Add this while soaking in the cold bath
- Make sure to stir while adding the hot water to avoid increasing the temperature too much (do not exceed 110 °F), which can result in a burn
- The extremity being treated will be desensitized from being in the cold water, making it difficult to discern if the temperature is too hot
- To increase the effectiveness of the contrast bath, add ice or ice packs to the cold water to help maintain the temperature between 45 – 70 °F
How Contrast Bath Therapy Works
The theory behind the use of contrast baths in physical therapy is that the rapid change from warm to cold helps to quickly open up and close the tiny capillaries (blood vessels) in your body. Warmth causes these small arteries to open, which cold causes them to close.
This rapid opening and closing of blood vessels near the site of your injury creates a pumping action that's thought to help decrease swelling and inflammation around injuries. Decreasing the swelling and inflammation helps alleviate pain and improve mobility.
Contraindications
DO NOT do contrast baths for any of the following problems:
- Local malignancies
- Peripheral Vascular Disease (PVD)
- Impaired sensation
- Bleeding and acute inflammation
- Diabetes and neuropathy
If there is a good pulse in the extremities, diabetics and those with neuropathies can benefit from a contrast bath, but it needs to be under the supervision of a physical therapists
Risks
Contrast baths carry no risk when performed correctly. The main risks are:
- Burns from water that is too hot
- Skin damage from water that is too cold
Ensuring that the water you use for contrast baths is the correct temperature is the best way to mitigate these risks.
Research
Contrast baths haven't garnered much attention from researchers. However, what little has been done suggest it's an effective treatment.
A 2013 meta-analysis found little difference in outcomes when comparing contrast baths to other physical therapy treatments.
A study published in 2018 measured the effects of contrast baths on intramuscular hemodynamics and oxygenation and found what appears to be beneficial changes post-treatment.
A plantar fasciitis study found that a conservative regiment involving contrast bath was as effective as steroid use. A study on contrast baths and hand volume in both pre-surgical and post-surgical cases of carpal tunnel showed no improvement.
Other studies suggest that contrast baths may be more effective than rest for relieving muscle soreness after exercise, but these studies were performed using elite athletes and not weekend warriors or non-athletes. That doesn't mean the results have no value for other people, but it does mean you should ask your therapist why they're considering this modality and whether any other, more evidence-based therapies are available for your specific condition.
