Consensus agreement on the design and conduct of clinical studies with low-level laser therapy and light therapy for musculoskeletal pain and disorders.

Definition. Low level laser therapy (LLLT) in musculoskeletal disorders refers to monochromatic light therapy with lasers which have a mean optical output of larger than 1 mW, i.e. lasers in classes III and IIIa. A similar definition applies for light therapy with light emitting diodes (LEDT) when the mean optical output is larger than 1 mW. Trial reports should make explicit whether LLLT or LEDT is being used. 1. In general, clinical trials with low level laser therapy (LLLT) should have a control group where patients receive placebo-LLLT or another reference treatment, and include procedures for randomization and patient-blinding, 2. The reporting of a trial should be presented according to the CONSORT guidelines from The Lancet (http://www.consort-statement.org). 3. Several leading journals require, or will in the near future require, that the trial is registered in a public trials register, prior to the start of the trial to ensure that not only positive results are being published. Several registers exist, and one such register can be found at 4. In particular, item 4 in the CONSORT guidelines, calls for a specific description of the intervention. A specific description of LLLT should include the number of treatment session and the frequency of sessions per week, and the following parameters from one treatment session mandatory [1, 2]: Application procedure: 1) Stationary in skin contact or 2) Stationary with distance from skin described or 3) Scanning mode Wavelength reported in nanometers Average output of the laser reported in milliWatts (mW) Treatment time in seconds Energy Dose delivered reported in Joules (reporting in J/cm 2 should be confined to studies with small animals and cell cultures)