Effects of photobiomodulation therapy and topical non-steroidal anti-inflammatory drug on skeletal muscle injury induced by contusion in rats —part 1: morphological and functional aspects

The objective of the present study was to evaluate and compare the effects of PBMT, with different application doses, and topical NSAIDs, under morphological and functional parameters, during an acute inflammatory process triggered by a controlled model of musculoskeletal injury induced via contusion in rats. Muscle injury was induced by means of a single trauma to the animals ’ anterior tibialis muscle. After 1 h, the rats were treated with PBMT (830 nm; continuous mode, with a power output of 100 mW; 3.57 W/cm2; 1  J–35.7 J/cm2, 3  J–107.1 J/cm2, and 9  J–321.4 J/cm2; 10, 30, and 90  s) or diclofenac sodium for topical use (1 g). Morphological analysis (histology) and functional analysis (muscle work) were performed, 6, 12, and 24 h after induction of the injury. PBMT, with all doses tested, improved morphological changes caused by trauma; however, the 9 J (321.4 J/cm2) dose was the most effective in organizing muscle fibers and cell nuclei. On the other hand, the use of diclofenac sodium produced only a slight improvement in morphological changes. Moreover, we observed a statistically significant increase of muscle work in the PBMT 3  J (107.1 J/cm2) group in relation to the injury group and the diclofenac group (p <  0.05). The results of the present study indicate that PBMT, with a dose of 3 J (107.1 J/cm2), is more effective than the other doses of PBMT tested and NSAIDs for topical use as a means to improve morphological and functional a...
Source: Lasers in Medical Science - Category: Laser Surgery Source Type: research