Effect of global postural re-education and isostretching in patients with nonspecific chronic low back pain: a randomized clinical trial [I] Efeitos da reeducação postural global e do isostretching em pacientes com lombalgia crônica não-específi ca: ensaio clínico aleatório [A] Fábio Alexandre Moreschi Guastala [a] , Mayara Hilda Guerini [ Abstract Introduction: Low back pain is one of the most prevalent musculoskeletal disorders, but little is known about postural methods in its treatment. Objective: Analyze changes in muscle strength, lexibility, function and pain in patients with chronic low back pain that underwent isostretching and global posture reeducation (GPR). Methods: Thirty-nine patients, aged between 40 and 59 years, were evaluated before and after treatment protocols regarding: lexibility for sit and reach, muscle strength, functional capacity using the Rolland-Morris Questionnaire, and intensity of pain by Visual Analog Scale. The sample was randomized into two groups (1-GPR; 2-Isostretching), all of whom were treated individually through 12 sessions lasting 45 minutes each, twice a week. Results: After treatment, median reduction in pain intensity of 28 mm in group 1 and 32 mm in group 2 was observed, and a median improvement in functional capacity in group 1 of 8.5 points and 7 points in group 2 (p < 0,05). A mean improvement of severn repetitions in trunk extensor muscle strength was observed in group 1 and in group 2; by dynamometry of 10 kg / f in group 1 and 12.5 kg / f in group 2 of ten abdominal repetitions strength in group 1 and four repetitions in group 2 (p < 0.05).In the Sit and Reach, Group 1 had a total mean increase of 3cm, and group 2 had 1.6cm (p < 0.05). Conclusion: Both groups were effective in improvement of muscle strength, lexibility, pain and functional capacity. Keywords