Photobiomodulation (PBM) has demonstrated positive effects on the muscle repair process. The aim of the study was to evaluate the effects of infrared PBM using different light sources—low-level laser (LLL) at 780 nm (40 or 70 mW, 10 J/cm², 0.4 J) or LED at 850 nm (40 or 70 mW, 0.13 J/cm², 0.4 J)—and dosimetric parameters on the proliferation and migration of muscle cells. The results showed that LLL 40 mW and 70 mW, with the same radiation exposure, led to an increase in proliferation after 24 h, but no differences at 48 and 72 h. Cells irradiated with LED 70 mW exhibited an increase in proliferation in comparison to the control group and 40mW after 24 and 48 h, but not at 72 h. Moreover, cell migration was greater in comparison to the control after 6 and 24 h, and no differences were found at 12 h when LLL was used with an output power of 70 mW. Furthermore, no differences were found at 6 and 12 h with the 70 mW output power-LED, but an increase was observed in the cell migration after 24 h. In conclusion, PBM using different light sources and dosimetric parameters was able to modulate the proliferation of C2C12 myoblasts, but only PBM at 70 mW was able to modulate the migration of these cells.

Background: This study aimed to evaluate the electrical activity of the rectus femoris, tibialis anterior, and lateral gastrocnemius muscles during the sit-to-stand task and functional mobility after a neurofunctional physiotherapy protocol associated with PBM. Methods: Twenty-five children were randomly allocated to either Active PBM + physiotherapy (n = 13) or PBM sham + physiotherapy (n = 12). PBM was carried out with a LED device (850 nm, 25 J, 50 s per point and 200 mW) at four points over the area with absence of a spiny process. Both groups completed a twelve-week supervised program with two weekly 45–60 min sessions. Pre-training and post-training assessments involved the Pediatric Evaluation of Disability Inventory (PEDI). Muscle activity was assessed using portable electromyography (BTS Engineering) and the electrodes were positioned on the lateral gastrocnemius, anterior tibialis, and rectus femoris muscles. The RMS data were recorded and analyzed. Results: After 24 sessions of the treatment protocol, improvements were found in the PEDI score. The participants presented greater independence in performing the tasks, requiring less assistance from their caregivers. More significant electrical activity was found in the three muscles evaluated between the rest period and execution of the sit-to-stand tasks, both in the more compromised or less compromised lower limbs. Conclusion: Neurofunctional physiotherapy with or without PBM improved functional mobility and electrical muscle activity in children with myelomeningocele.