Low reactive level laser therapy (LLLT) involving low incident levels of laser light, is known for its normalizing effect on abnormalities of living bodies. A joint study by Keio University Institute of Physical Education Japan Medical Laser Laboratory and the Ohshiro Clinic was conducted to investigate the application of the GaAlAs diode laser in the field of sports medicine during pre-training or pre-competition warm up and post-training cooling down. The ‘Sit and Reach’ test, blood oxygenation and pulse rates were measured in 17 athletes, 15 males and 2 females, before laser irradiation (A), after the first laser irradiation (B), after physical exertion (C) and after a second laser irradiation (D). The Oh-Lase HT 2001 semi-conductor laser was applied to the neck while the subject adopted a sitting position on the floor with the legs stretched forward. The subjects were requested to stretch (toe-touch) as far as possible followed by another 8 seconds of laser irradiation while the subjects were stretched and were measured for maximum stretching distance. The procedure was repeated. When statistical significance was evaluated there were significant changes between A and B, A and C, A and D, B and D, and C and D in the performance of the Sit and Reach Test, whereas significant differences in heart rate were seen between A and C, B and C, B and D, and C and D, and significant differences between A and B, A and D, B and C, and C and D in the blood oxygen saturation level. The results where significant differences between A and B, and C and D imply that the use of the GaAlAs laser during warm up and cool down is beneficial.

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The purpose of the current study was to determine the effectiveness of hyperbaric oxygen therapy(HBOT) or laser therapy in the acceleration of chronic venous ulcer healing. Thirty hospital inpatients with venous ulcers participated in this study for a treatment period of five weeks. They were divided randomly and equally into three groups (2 treatment groups and one control group). Patients in group (1) (HBOT group) received two 90 minutes treatments daily with 2 to3 L of humidified oxygen / minute at 22 mmHg. On the other hand, patients in group (2) (laser therapy group) received 1 J/cm² infrared laser (Ga As), three times weekly. Patients in group (3) (control group) received standard wound care only. Wound surface area (WSA) and wound volume (WV) were used to measure the outcomes before starting the study and after the 3^rd and 5^th weeks posttreatment. It was found that, at the 5^th week post-treatment there was a significant reduction in both WSA and WV in both the HBOT group and the laser therapy group when compared to the control group (P<0.0001), also there was a significant reduction in WSA and WV in the laser therapy group at the 5^th week post-treatment when compared to the HBOT group (P<0.001). The findings strongly suggest that the application of infrared laser therapy at a dose of 1J/cm², three times/week is more effective than the application of HBOT daily in the management of chronic venous ulcers.

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In the treatment of Perthes disease, femoral head collapse often develops during conventional treatment, and some investigators have reported the absence of any significant difference in the prognosis between conservatively treated cases and untreated cases. Thus, no consensus has been reached about the effectiveness of the conventionally used conservative therapy. We previously reported, for the first time in the international literature, the possibility of shortening the treatment period and preventing aggravation of femoral head deformity in patients with Perthes disease by starting treatment as early as possible using a combination of non-weight bearing brace therapy and near-infrared (near-IR) irradiation. In the present study, we compared the treatment outcomes in 16 cases of Perthes disease treated with near-IR irradiation with 11 cases not treated with near-IR energy focusing on the time-course of changes in the lateral pillar height (which is the factor most closely related to the treatment outcome) and demonstrated that if treatment with near-IR energy,combined with leg traction and brace therapy, is started in the early stage of Perthes disease, alleviation of all of the restricted range of hip motion, hydrarthrosis and lateral subluxation of the hip could be obtained, with stimulation of lateral pillar formation. In addition, it was shown that when thorough non-weight bearing brace therapy is combined with near-IR treatment, patients are unlikely to show delayed healing of necrosis due to femoral head collapse or the vicious circle of aggravation of the femoral head deformity; the therapy may be expected to accelerate repair on the medial and lateral sides of the femoral head nucleus, with shortening of the disease treatment period and prevention of aggravation of femoral head deformity. Near-IR irradiation is more useful than conventional conservative therapy and is an exciting and novel therapeutic modality for aseptic necrosis of the femoral head, the characteristic feature of Perthes disease.

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Spasticity following cerebral vascular accidents (CVAs) is a common occurrence, but remains a problematic entity to treat and interferes with mobility and self-care activities which are critical for successful rehabilitative outcomes. Low reactive-level laser therapy (LLLT) has attracted attention in a number of areas including spasticity associated with cerebral palsy. In the case of post CVA therapy, LLLT has been reported for pain treatment, but not spasticity. The present study examined the efficacy of LLLT in attenuating triceps surae muscle spasticity in CVA patients. The study subjects comprised 15 chronic CVA patients with spasticity, treated at our university hospital between 2002 and 2006. The LLLT device we used was a near infrared (830 nm) semiconductor laser device delivering 1 W in continuous wave (irradiance, 670 mW/cm²) . The laser probe was applied with mild pressure to the skin over the tibial nerve on the affected side, 30 sec/point (dose/point 20.1 J/cm²) repeated 3 times with a 5 sec interval between irradiations. Two sessions were given per week for 1 week. At the end of the week, we recognized LLLT effects in 11 cases out of 15. The other 4 patients had little or no effect but were in their fifties, and had successive bouts of ankle clonus. LLLT is a promising medical treatment for the attenuation of CVA-related spasticity of the triceps surae muscle spasticity, and facilitate voluntary movements in such patients. Further studies are warranted to elucidate the mechanisms by which LLLT can attenuate spasticity.

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Plastic and reconstructive surgery (PRS) is a field in which any congenital or acquired abnormalities in patients are corrected, including dyschromic skin lesions or tumorous lesions^{(1, 2)}. Laser treatment is effective in such cases, however incorrect choice of lasers and incorrect use of a laser may be more detrimental than therapeutic to the patient. Recent advances in laser surgery and the increase in new laser technologies have necessitated these guidelines for the safe usage of lasers. The purpose of these guidelines is to set a safety standard for the use of high output lasers thereby securing the safety of all involved in laser treatment.

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The treatment principle of endoscopic high reactive level laser treatment (HLLT) of the gastrointestinal tract is the vaporization and coagulation of the diseased lesion. Histological changes are caused by the photothermal reaction which is directly related to the increase of temperature of the laser-irradiated field. High outputs of 60 to 100 W can cause tissue to vaporize while outputs of 20 to 50 W can cause protein denaturation and coagulation. The amount and degree of tissue damage is dictated by the energy density (output x irradiation time/cm²) of the incident laser. At lower outputs of 2 to 3 W, laserthermia is anticipated, however using a high output hardware to achieve this is unadvisable and a specific hardware intended for this purpose should be used. When output of a laser mistaken, dangers of perforation and burning of the scope arise. The purpose of these Safety Guidelines is to provide information for the proper use of lasers in order to secure the safety of both the patient and the physician during the use of lasers in endoscopic procedures of the digestive tract.

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