Injury rehabilitation and physical therapy use hot and cold therapy as a regular part of the rehab process. It is a simple technique you can take home and use whenever you need it. It is easy, practical, and very useful to reduce pain and improve the lesion’s outcome. However, you need to know a few tips to prevent potential issues and make proper ice therapy use in pain management. One of the most critical questions is how long should you ice your knee, and in this article, we’re covering the answer.
What is the correct technique to ice your knee?
The best way to use ice therapy is by time intervals of 10 minutes. So, you should only apply ice for 10 minutes, then remove the cold compress for a while. You can repeat the process after a time, but leaving the ice in your knee sometimes causes a type of skin injury known as frostbite, which features skin damage when blood flow is not continuous in the skin. It doesn’t happen to everyone, but 10 minutes are recommended to make sure it won’t happen to you. After leaving your knee for a few minutes, and when it feels back to its normal temperature and feel, you can resume applying ice 10 more minutes, and keep doing that several times a day.
Every individual is different, and microcirculation behaves differently in each one of us. So, the recommendation of 10 minutes is usually appropriate but may be too much for some people. How do you know? You can simply keep track of ice packs’ effects on your knee by staying alert to body sensations.
When you use an ice pack on your knee or any other body part, here’s what you should feel:
- Cold: First off, you feel cold in the area; sometimes, it triggers chills or goosebumps. In this stage, your skin cold receptors are activated and then overwhelmed.
- Burn: After a short while, the cold sensation is replaced by a slightly burning one. It only lasts for a few minutes. In this stage, cold receptors are exhausted, and nerve terminals continue firing.
- Ache: An ache can replace this mild burning sensation. It is often described as tiny needles on the skin. In this stage, blood circulation is starting to change.
- Numb: Finally, you start feeling numbness in the skin. In this stage, blood circulation changes are done, and nerve terminals stop receiving a continuous blood flow. When you feel this, it’s time to remove the ice because the job is already done.
Something you can do to cover a larger area is an ice massage. This would also contribute by not letting ice sit in the same spot for a very long time, which further reduces the risk of frostbite.
Also, if you want to accelerate the process, elevate your injured leg. This will help your veins return blood circulation to the heart faster, which improves swelling and helps you recover more quickly.
Types of ice packs you can use and how
You can choose between a variety of ice packs and temperature therapy solutions. One of the best you could use is a commercial icing product. They usually have a gel-like substance sealed in plastic or a similar setup and can be taken to the fridge and reused as much as you need. One of the best aspects of commercial ice packs is that they come in different designs depending on the body part you need to cover, and some of them are appropriate to wrap around your knee.
You also have other homemade alternatives. For example:
- Frozen foods: It is probably the fastest solution you can use, by taking frozen food packs from the freezer and use them as an ice pack.
- Ice cups: You can prepare your own ice packs using one of these paper cups, filling them with water and putting them in the freezer. When the ice is completely solid, you can massage your knee with the ice cup following circular patterns.
- Homemade ice pack: One of the best ice pack solutions is pretty simple and only needs ice cubes and a plastic bag. Place the ice in a sealed plastic back (a Ziploc or similar) and use it on your knee. You can also add rubbing alcohol to prevent ice cube fusion in a big block.
What’s the role of temperature in knee pain and healing?
In the introduction of this article, we mentioned frostbite. It features skin damage due to a lack of blood circulation typically caused by cold temperatures. The blood vessels and microcirculation of the body respond very well to body temperature. In higher temperatures, the blood vessels tend to expand and carry more blood. In lower temperatures, the blood vessels tend to contract, and blood circulation is slower.
We would typically think that excellent circulation is what we need to feel better, but the reason why we use ice to slow down the circulation has to do with inflammation. As more blood keeps reaching your injured knee structures, more inflammatory cells reach the area, more inflammatory substances are released, and the process continues causing swelling and pain. Ice prevents this from happening, and if you take our recommendation above, it won’t have a chance to compromise your blood circulation.
But sometimes, a combination of hot and cold therapy is better than only using cold therapy. In these cases, hot temperatures expand the blood vessels and contribute to resuming blood circulation. Talk to your doctor to know if your condition requires a combination of hot and cold therapy or if you’re better off with an ice pack only.
Oosterveld, F. G. J., Rasker, J. J., Jacobs, J. W. G., & Overmars, H. J. A. (1992). The effect of local heat and cold therapy on the intraarticular and skin surface temperature of the knee. Arthritis & Rheumatism: Official Journal of the American College of Rheumatology, 35(2), 146-151.
Markert, S. E. (2011). The use of cryotherapy after a total knee replacement: a literature review. Orthopaedic Nursing, 30(1), 29-36.