# Effects of Photomodulation Therapy for Delayed Onset Muscle Soreness: A Systematic Review and Meta-Analysis

## TL;DR

This study finds that photomodulation therapy can reduce muscle soreness and improve strength after exercise-induced muscle damage.

## Contribution

The study provides a meta-analysis showing PMT's effectiveness in reducing DOMS pain and improving muscle strength.

## Key findings

- PMT significantly reduced pain scores at 72 and 96 hours after DOMS induction.
- Muscle strength improved significantly at 24 and 48 hours with PMT.
- PMT may help reduce biochemical markers of muscle damage.

## Abstract

Objectives: This study aimed to evaluate the effects of photomodulation therapy (PMT) on delayed onset muscle soreness (DOMS). Methods: Controlled studies investigating PMT for DOMS were identified through systematic searches of PubMed and EMBASE databases. Selected articles were reviewed for the effects of PMT, and the outcome data were extracted according to specific assessments and time points for meta-analysis. Results: A total of 14 studies met the inclusion criteria, all of which evaluated the effects of PMT following the induction of DOMS. The wavelength of PMT ranged from 660 to 950 nm and was applied to one to six points on the affected muscles. Four studies provided sufficient data for quantitative synthesis, comparing PMT with the placebo in terms of visual analog scale (VAS) scores and muscle strength at 24, 48, 72, and 96 h after the induction of DOMS. The results demonstrated a statistically significant reduction in VAS scores at 72 h (pooled SMD = −0.55) and 96 h (pooled SMD = −0.56), indicating a moderate effect. Muscle strength showed significant improvement at 24 h (pooled SMD = 0.97) and 48 h (pooled SMD = 0.99), reflecting a large effect size. Conclusions: These findings suggested that PMT may be an effective intervention for managing DOMS, with potential effects on reducing pain, enhancing muscle strength, and decreasing biochemical markers of muscle damage.