LLLT is a non-invasive light source treatment that generates a single wavelength of light. It emits no heat, sound, or vibration.
A 2017 systematic review and meta-analysis from Clijsen et al. found that LLLT is an effective treatment modality to reduce pain in senior and older adult patients with musculoskeletal disorders. They also noted that adherence to the World Association of Laser Therapy (WALT) dosages improved the effectiveness.
Reference: Clijsen R, Brunner A, Barbero M, Clarys P, Taeymans J. Effects of low-level laser therapy on pain in patients with musculoskeletal disorders: a systematic review and meta-analysis. Available from: https://www.ncbi.nlm.nih.gov/pubmed/28145397/