16 Energy for Health [10] ABSTRACT Background: It is estimated that 30%-50% of women will suffer an osteoporotic fracture in their lifetime. Laser therapy has a positive effect on bone regeneration and healing that is dependent on the characteristics of the light itself (eg, intensity and wavelength). Objective: The aim of the present study was to compare the possible effect of High Intensity Laser Therapy (HILT) versus Low Level Laser Therapy (LLLT) on bone mineral density (BMD) of lumbar vertebrae in postmenopausal women with osteoporosis. Methods: Thirty postmenopausal osteoporotic women participated in the study and were randomly divided in two groups. Group I consisted of 15 women receiving HILT, Group II consisted of 15 women receiving LLLT. Both groups have been exposed to three sessions of treatment per week for six successive weeks. Bone Mineral Density (BMD) of lumbar spine (L1.-5) was measured by Dual X-ray absorptiometry (DXA). Evaluation of lumbar BMD was performed before and after the end of the six weeks of treatment. Results: Comparing mean values before and after treatment, the BMD measures showed that both groups had a statistically significant improvement after laser therapy. Comparing the two groups, the improvement showed by BMD was higher in Group I (HILT) than in Group II (LLLT). The difference between the two groups was statistically significant (P > 0.05) Conclusion: Laser can be an effective method for the management of osteoporosis and improvement of BMD in postmenopausal women. On the basis of the findings of this study, HILT results more effective than LLLT. INTRODUCTION Osteoporosis has been defined as a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk [1,2]. Osteoporosis and fractures related to bone fragility represent a serious and global public health problem. Currently, it is estimated that 30%-50% of women and 15%-30% of men will suffer an osteoporotic fracture in their lifetime. It is a silent epidemic that has become a major health hazard in recent years, afflicting over 2000 million people worldwide [3]. There are two types of osteoporosis: type I, due to a decrease in cumulating estrogens, which affects trabecular bone (especially vertebral bone) and affects females more than males, in a ratio of 6:1; type II, senile osteoporosis, which is age related and occurs in cortical and trabecular bone, affects females and males in a ratio of 2:1 [4]. One in three High Intensity Laser Versus low Intensity Laser Therapy in Management of Postmenopausal Osteoporosis. Ali Abdel Monsif Thabet 1 , Mohamed Salah Eldien Mohamed 2 , Mohamed Mohamed Ibrahim Ali 3 , Omar Farouk Helal 4 . 1. PhD in Physical Therapy, Lecturer Physical therapy, Department of Physical Therapy for Obstetrics and Gynecology, Faculty of Physical Therapy, Cairo University. Research interest (Expertise): Physical Therapy for Obstetrics and Gynecology. 2. PhD in Physical Therapy, Lecturer Physical Therapy, Department of Basic Science, Faculty of Physical Therapy, Cairo University Research interest (Expertise): Therapeutic modalities and Electrotherapy 3. PhD in Physical Therapy, Lecturer Physical therapy , Department of Physical Therapy for Musculoskeletal Disorders, Faculty of Physical Therapy, Cairo University. Department of Physical Therapy, Faculty of Applied Medical Sciences, Umm Al-Qura University. Research interest (Expertise): Physical Therapy for Musculoskeletal Disorders. 4. PhD in Physical Therapy, Assistant Professor of Physical Therapy, Department of Physical Therapy, Faculty of Applied Medical Sciences, Umm Al-Qura University. Research interest (Expertise): Physical Therapy for Cardiopulmonary and Geriatrics. Key words: HILT, LLLT, Bone Mineral Density, Postmenopausal Osteoporosis