The effects of infrared-830 nm laser on exercised osteopenic rats.

The aim of this study was to investigate the effects of low-level laser therapy (LLLT), 830 nm, on femora of exercised osteopenic rats. Sixty female rats were used, which were divided into six groups: sham-operated control, osteopenic control, sham-operated trained, osteopenic trained, sham-operated trained and irradiated, and osteopenic trained and irradiated. The exercise program and the laser irradiation were performed 48 h over an 8-week period. The exercise program was made in a container, filled with warm water, and consisted of jumps (four series, with ten jumps). The laser irradiation was performed with a Ga-Al-As laser, 830 nm, 100 W/cm2, 120 J/cm2. Femora were submitted to a physical and geometrical properties evaluation, a biomechanical test, and calcium and phosphorus evaluation. Exercised animals showed higher bone strength and physical properties values. However, the LLLT did not improve the stimulatory effects of the exercise on the osteopenic rats. The exercise program was able to increase femora strength and physical properties of osteopenic rats. However, concurrent treatments did not produce a more pronounced effect on femora.