A randomized, two arm, open label, active controlled, multicentric clinical study to evaluate the efficacy and safety of a topical formulations of diclofenac (2.32% w/v solution) with Methyl Salicylate 10% w/v and Menthol 5% w/v versus a topical Diclofenac Gel (1.16% w/w) with Methyl Salicylate 10% w/w and Menthol 5% w/w in acute low back ache and sprains.