Influence of phototherapy on sensorimotor excitability of healthy muscle

The aim of this study is to assess the influence of laser irradiation and incoherent infrared radiation on sensorimotor excitability and muscle pain after a workout. The research was carried out on 40 healthy volunteers who were randomly divided into four groups. A single phototherapy treatment, preceded by the triceps calf muscle workout, was applied in all the groups. Group 1: low-level laser therapy (LLLT), group 2: high-intensity laser therapy(HILT), group 3: infrared radiation (IR), group 4: placebo was applied. The electrodiagnostic examination was performed on the first day, before a workout and irradiation, as well as 48 hours after the workout. Moreover, pain intensity assessment (VAS) was performed 24 and 48 hours after workouts. A statistically significant increase in the average threshold limit value of accommodation after a workout was observed in the IR group, in contrast to the HILT group, in which a decrease in the average threshold limit value of accommodation was observed. In the IR and LLLT groups, the value of rheobase increased. A statistically significant decrease in pain was observed in the LLLT and IR groups. The post-exercise irradiation with LLLT and incoherent IR influenced a decrease in sensorimotor excitability and decrease in pain of the muscle after a workout.