Laser Therapy for Knee Pain: What the Evidence Shows

People often ask whether laser therapy helps knee pain, especially knee osteoarthritis. This page explains what the research shows, what guidelines recommend, and how we use laser at our clinic in Monkstown, Co. Dublin.

The short answer

• Exercise is the main treatment for knee osteoarthritis. A strengthening and movement programme, with advice and weight loss where it applies, is what guidelines recommend first [1][2].
• NICE does not recommend laser for osteoarthritis. Its guideline says not to offer electrotherapy, including laser, because there isn't enough evidence of benefit [1].
• Some trials are more positive. A review of placebo-controlled trials found that low-level laser at recommended doses reduced knee osteoarthritis pain in the short term, for up to about 12 weeks [3].
• Laser is available on request, after we've discussed the evidence with you, and only alongside exercise.

What is laser therapy?

Laser therapy shines light through the skin into the tissues underneath. It is not painful and it isn't a surgical laser. It is thought to affect pain signalling and inflammation, but how much it helps varies a lot between conditions and between people.

Most of the positive research on knee osteoarthritis used low-level lasers [3]. Our clinic uses a Class IV (high-power) laser. The research on high-power laser for knee osteoarthritis is smaller and weaker, so we can't promise the same results.

What helps knee osteoarthritis most?

Guidelines agree on the core treatments [1][2]:

• Exercise: strengthening the muscles around the knee and hip, and general activity such as walking, cycling or swimming. In a large review of trials, exercise reduced knee pain and improved function compared with no exercise, though the improvement is usually modest and builds over weeks [2].
• Advice and support: understanding the condition, pacing, and knowing that exercise doesn't "wear out" the knee.
• Weight loss, if it applies to you: losing 10% of your body weight is likely to help more than 5% [1].
• Hands-on treatment can be added, but only alongside exercise [1].

See our pages on knee pain and osteoarthritis for more.

If you'd like to try laser

If you ask about laser for your knee, we'll explain the evidence honestly first. If you'd still like to try it, we use it:

• alongside your exercise programme, never instead of it
• as a short trial, measuring your pain and function at the start and the end
• stopping if it isn't clearly helping

Laser isn't suitable for everyone. For example, it isn't used over the eyes, a pregnant abdomen, or areas of active cancer. Your clinician checks this at your assessment, and you wear safety goggles during treatment.

See your GP or get urgent help if

• your knee is hot, red and swollen and you feel unwell or have a high temperature: go to an emergency department the same day
• you can't put weight on your leg after an injury
• your knee locks and you can't straighten it, or keeps giving way

Book an assessment

Your first visit is an assessment with our chiropractor or Chartered Physiotherapist, and includes a first treatment if it's suitable. You can book an appointment or contact us with any questions.

Sources

1. National Institute for Health and Care Excellence (2022). Osteoarthritis in over 16s: diagnosis and management (NG226). https://www.nice.org.uk/guidance/ng226
2. Lawford BJ, Hall M, Hinman RS, et al. (2024). Exercise for osteoarthritis of the knee. Cochrane Database of Systematic Reviews, CD004376. https://doi.org/10.1002/14651858.CD004376.pub4
3. Stausholm MB, Naterstad IF, Joensen J, et al. (2019). Efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials. BMJ Open 9:e031142. https://doi.org/10.1136/bmjopen-2019-031142