Feasibility study of a LED light irradiation device for the treatment of chronic neck with shoulder muscle pain/stiffness

What the authors concluded

Immediately after irradiation, the subjective symptoms of the neck with shoulder muscle stiffness and pain evaluated by a visual analog scale were improved from 58.3 mm ± 18.7 mm to 45.5 mm ± 21.5 mm and from 45.8 mm ± 23.3 mm to 39.4 mm ± 21.8 mm, respectively. The symptoms further improved after 15 minutes of irradiation." "The skin temperature at the irradiated point increased from 34.3°C ± 1