Fig 1.
CONSORT diagram.
Fig 2.
The effect of LED light irradiation on the VAS for chronic neck with shoulder muscle stiffness and pain for each subject.
Variations in VAS scores of the (A) neck with shoulder muscle stiffness and (B) pain before, immediately after, and 15 minutes after treatment.
Fig 3.
The effect of LED light irradiation on the skin surface temperature.
(A) Variations in the skin surface temperature around the LED light irradiation site of each study participant before, immediately after, and 15 minutes after treatment. (B) Thermography images of the skin surface before (upper left), immediately after (upper right), and 15 minutes after LED irradiation (lower left).
Fig 4.
The effect of LED light irradiation on the heart rate viability and baroreceptor reflex sensitivity of each study participant.
Variations in (A) low frequency power, (B) high frequency power, (C) low frequency power/high frequency power ratio, and (D) baroreceptor reflex sensitivity before, immediately after, and 15 minutes after LED light irradiation.
Table 1.
Changes in the heart rate variability and baroreceptor reflex sensitivity.