This paper reviews a study conducted by researchers at the University of Miami School of Medicine in Miami, Florida using the original Respond Systems model 2400 laser therapy system. The study demonstrates that laser treated tendons healed twice as strong as those that receive no laser therapy. Gallium-Arsenide Laser Photostimulation Augments the Strength of Healing Rabbit Calcaneal Tendons. Chukuka S. Enwemeka and Ivette Rodriguez,  Research Service, Veterans Affairs Medical Center & Department Of Orthopedics & Rehabilitation, Division of Physical Therapy, University of Miami School of Medicine, Miami, Florida. Laser photostimulation has been purported to promote fibroplasia and collagen synthesis  in skin wounds. To test the hypothesis that GaAs laser promotes collagen synthesis and hence augments the strength of  healing tendons, the right calcaneal tendons of 2l rabbits were tenotomized, repaired and immobilized in plaster casts.  Then, beginning one day after surgery, the repaired tendons of 14 rabbits were exposed to 904nm GaAs laser of 1 J cm-2 (N=7 tendons) or 1.5J cm-2 (N=7 tendons) daily. The remaining 7 tendons served as nontreated controls.  On the 14 post-operative day, the tendons were excised, and tested on an Instron device for differences in tensile strength and tensile stress. Analysis of variance showed that the mean tensile strength of photostimulated tendons, 94.7±12.25N_and 89.7±10.83n for I Jcm-2 and 1.5 J cm-2 respectively, were significantly different from the control values, 56.4±4.05N.  Subsequently,  Student Neuman Keul post hoc test revealed that  stimulation at 1 J cm-2 significantly increased the tensile strength of the tendons over controls.  Correspondingly, the mean tensile stress of stimulated tendons, 251. 6±34.35 N cm-2 dose and 221.60± 30.94 N cm-2 for the 1.5 J cm-2 dose, were significantly higher than mean control value, 153.56±11.64N cm-2. No differences were found in the mean tensile  strength and mean tensile stress of tendons stimulated at the two doses. These findings indicate that 1 or 1.5J cm-2 GaAs laser augments the healing strength of experimentally tenotomized rabbit  calcaneal tendons and that doses greater than 1 Jcm-2 may not promote healing better than a dose of 1 Jcm-2 Paper presented at the American Society for Laser Medicine and Surgery, April 29, 1991, San Diego, Ca. U.S.A PC/09-23-97  Office Documents - Therapy Papers - Gallium-ArsenideLaser Photostimulation.