Effect of photobiomodulation therapy on trunk flexor performance after incisional hernia repair: a randomized controlled trial.

To investigate the effect of two photobiomodulation approaches on trunk flexor performance after incisional hernia repair and to compare the effects of both wavelengths. Forty-five patients were randomly distributed after isokinetic trunk flexor assessments into infrared laser, red laser, and placebo groups. Each patient received laser treatment followed by a traditional physical therapy program. In laser treatment, 24 points in both recti were irradiated by infrared or red laser light with the following parameters; 0.6 J per point, 214.28 J/cm2 as energy density, and 17.85 W/cm2 as intensity, while the control group received a placebo approach. All groups received clinical treatments at a rate of 3 sessions per week for 4 weeks; in addition, the physical therapy program was continued on other days for all groups. Isokinetic trunk flexor strength was measured before treatment and 4 weeks after treatment as in each measurement, fatigue protocol was designed, and the trunk flexor strength was measured before fatigue test while the trunk flexor resistance to fatigue was measured after fatigue test. After 4 weeks, pre-and post-fatigue trunk flexor strengths in both laser groups were significantly increased compared to pre-and post-fatigue trunk flexor strength in the placebo group, respectively, and there was no significant difference between the two laser groups. Photobiomodulation approaches enhance trunk flexor response to exercise after incisional hernia repair. This enhancement leads to greater strength and more fatigue resistance for the trunk flexors in photobiomodulation groups compared to the placebo group and no difference between the two photobiomodulation effects.