Contrast Bath in Physical Therapy

A Special Type of Whirlpool Treatment

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There are many different types of treatments and modalities used in physical therapy. These treatments are designed to help decrease pain, decrease muscle spasm, improve range of motion and strength, and improve functional mobility.

One treatment that is occasionally used in physical therapy is the contrast bath. The contrast bath is a type of whirlpool treatment. Whirlpool treatments for injuries in physical therapy have been used for years. A special type of whirlpool treatment called a contrast bath can help improve circulation around your injured tissue.

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:

  • Decrease pain
  • Decrease swelling
  • Control inflammation
  • Improve 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.

Common Injuries That May Benefit from a Contrast Bath

Injuries that benefit from contrast bath treatments are those that cause swelling and pain ​around soft tissue and the joints of the body. These injuries include, but are not limited to:

How Contrast Bath Therapy Is Administered

To perform a contrast bath, you need two whirlpool tubs. One tub should be filled with warm water, and one tub with cold. The warm tub should be between 98-110 degrees Fahrenheit, and the cold tub should be 50-60 degrees Fahrenheit.

Often, physical therapy clinics will have only one tub, so a whirlpool tub and a bucket are used instead. Usually, the whirlpool tub is filled with warm water, and the bucket is filled with cold water and ice.

After ensuring that the warm and cold tubs are the correct temperature, you will be instructed to place your injured body part in the warm whirlpool. It should be left in the warm tub for a period of 3-4 minutes. While your body part is in the tub, you may be asked to perform gentle motion exercises.

After spending a few minutes in the warm tub, you then quickly move your body part being treated to the cold tub or bucket. Be prepared; the change from warm to cold can be pretty intense.

Typically, your body part should be kept in the cold water for about one minute. Of course, if you are unable to tolerate the cold for that long, let your physical therapist know and take your injured body part out of the cold water and place it back in the warm.

This sequence of moving from warm to cold and back again is repeated for 20-30 minutes. Be sure your physical therapist monitors the temperature of the water as you are going through treatment. Often, the water temperature will need to be adjusted by adding more ice or warm water to the respective baths to maintain the appropriate temperatures.

After treatment, your physical therapist should assess your injured body part to see if the treatment achieved the desired effect. Most likely, you will also be engaged in active exercises and functional mobility after the contrast bath treatment. Most research indicates that active involvement in physical therapy produces the best outcomes.

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 in the body. Warmth causes these small arteries to open; cold causes them to close.

The rapid opening and closing of the arteries near the site of your injury creates a pumping action. This pumping is thought to help decrease swelling and inflammation around the injured area. By decreasing the swelling and inflammation, pain can be reduced and improved mobility can be achieved.

Risks of Contrast Bath Therapy

There are very little risks associated with engaging in contrast baths. If the water is too hot, scalding of your skin may be a risk. Immersing in water that is too cold may also create a situation where skin is damaged due to cold temperatures. Ensuring that the water you use for contrast baths is correct is the best way to mitigate these risks.

What the Research Shows

When searching for research about the application of contrast baths for injury management in physical therapy, there is a lack of sound published evidence for its use. One meta-analysis found little difference in outcomes when comparing contrast baths to other PT treatments. Other studies that contrast baths may be more effective than rest for relieving muscle soreness after exercise, but these results apply to elite athletes and not weekend warriors or non-athletes. Does that mean it has no value? No, but you should ask your PT if it is necessary to do and if there are any other, more evidence-based therapies available for your specific condition. Contrast baths do not appear to carry any risk when applied correctly.

A Word From Verywell

Any good rehab program must consist of active involvement. Whirlpools and contrast baths are passive treatments that should be used to augment your PT treatment program. Contrast bath therapy is one technique that your physical therapist may use to help you quickly and safely restore normal mobility and function after injury or surgery.

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Article Sources
  • Bieuzen, F. Etal. Contrast Water Therapy and Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis. Plosone 8(4). E62356.