High-intensity laser therapy

High-power laser light is absorbed more deeply in tissue than light from low-level devices, producing local warming and photochemical effects that reduce pain, reduce inflammation and increase local circulation. Sessions are short and painless apart from a sensation of warmth.

The depth is what distinguishes it from low-level laser: superficial devices do not reach a hip joint or a lumbar disc, and much of the disappointing evidence for laser therapy comes from devices that never delivered energy to the target.

Tendinopathy, muscle and ligament injury, osteoarthritis pain, back and neck pain, and post-surgical pain and swelling. It is most useful where pain is the barrier preventing someone starting the exercise that will actually treat the problem.

Eye protection is worn by patient and operator. It is avoided over tumours, over the pregnant abdomen, and over implanted electronic devices.

The evidence for laser therapy is mixed and heavily dependent on dose and device. Pooled trials show short-term pain relief in several musculoskeletal conditions, although the certainty is low and the effect on pain tends to fade as follow-up lengthens 1; trials that measured cartilage do not show consistent structural change 2 3.

We use it as an adjunct to make active treatment possible, and we do not sell courses of it as a treatment in its own right.

It is used for pain relief and to reduce local inflammation so that active treatment can proceed. That is the claim, and we do not extend it.

The evidence is for short-term symptom change rather than structural repair, which is why it appears inside programmes as an adjunct and never as the programme itself.

These are class four lasers. Both patient and operator wear protective eyewear for every session, and the treatment room is controlled while the device is in use.

It is avoided over malignancy, over the pregnant uterus, over the thyroid gland and over areas of impaired sensation, where the person cannot report that the tissue is becoming too warm.

There is no good evidence that it does. The trials were built around pain and function, and those that measured knee cartilage on ultrasound disagree. One small trial reported thicker cartilage after laser combined with exercise 3. A double-blind, placebo-controlled trial found no difference in cartilage thickness, pain, strength or function when laser was added to supervised exercise; both groups improved, and the authors credited the exercise programme 2.

Pain relief is the realistic aim, and even that rests on low-certainty evidence 1. That is why laser is used to make exercise possible rather than to fix the underlying problem.