To Evaluate the Superiority of Fixed Combination (Orfenadrine 35mg, Acetaminophen 325mg, Caffeine 65mg and Diclofenac Sodium 50mg) Compared to Voltaren® (Diclofenac Sodium 50mg) in the Treatment of Acute Postural Low Back Pain.

The purpose of this study is to determine whether the fixed combination of orphenadrine, acetaminophen, caffeine and diclofenac sodium is more effective in the treatment of an acute episode of mechanical postural low back pain than Voltaren®. Will be randomized 110 participants of both sexes, aged 18 years or older and less than 65 years of age with an acute episode of mechanical postural low back pain and they will be allocated to one of two treatment groups: Group 1: Fixed combination of orphenadrine, acetaminophen, caffeine and diclofenac sodium; or Group 2: Voltaren®