An Investigator Initiated, Within-Subject, Proof of Concept Study to Assess the Efficacy and Safety of Voltaren Gel in Subjects With DOMS

Inclusion Criteria: * Patients who provide written informed consent prior to enrollment * Male or female and 18 to 35 years of age. * Patients who are not engaged in regular lower extremity fitness activities for more than 2 times per week for ≥2 consecutive weeks in the past 6 months prior to screening. * Female patients are eligible only if all of the following apply: * Not pregnant (subjects of child bearing potential must have a negative beta human chorionic gonadotropin (β-hCG) pregnancy test at screening); * Not lactating; * Not planning to become pregnant within the duration of the study; * Patients who are willing and capable of understanding and cooperating with the requirements of the study. * Patients able to understand and communicate in English. Randomization Inclusion Criteria: * Patients who report a DOMS score ≥4 at rest (numerical rating scale of 0 to 10, where 0 is no pain and 10 is worst pain imaginable) secondary to delayed muscle soreness on both right and left legs. The DOMS scores at rest reported for each leg must be within 3 points of each other. * Patients must report a categorical pain rating of moderate to severe for each leg on a scale of none, mild, moderate, or severe prior to randomization. Exclusion Criteria: * Have a body mass index of \>32 kg/m2 * History of active or suspected esophageal, gastric, pyloric channel, or duodenal ulceration or bleeding within 30 days preceding screening. * Psychiatric disease including major depression, bipolar disorder, or anxiety, or other medical condition that, in the opinion of the Investigator, would interfere with the evaluation of study drug efficacy or safety * History of clinically significant cardiovascular, cerebrovascular, metabolic, pulmonary, neurological, hematological, autoimmune, psychiatric or endocrine disorders, including individuals with Type I or Type II diabetes, or other clinically significant medical condition that, in the opinion of the Investigator, may preclude safe study participation. * Have had surgery or scheduled to undergo surgery of the hips or knees within 6 months prior to screening and/or during the study participation. * Have significant biomechanical abnormality in the lower extremity that would preclude study evaluations, such as: peripheral or central neurological disease, significant back pain; symptomatic osteoarthritis of the hips, knew, or feet, or other painful conditions of the lower extremities. * Have any type of orthopedic and/or prosthetic device or any skin abnormalities on the legs that may interfere with local tolerability. * Currently taking corticosteroids or topical analgesic or anti inflammatory treatment whose the duration of action may affect study evaluations. * Malignancy in the last 5 years, with the exception of nonmetastatic basal cell or squamous cell carcinoma of the skin that has been surgically cured, or any Stage 1 cancer or carcinoma in situ cured by resection or localized radiation at least 5 years prior to screening with no evidence of recurrence. * History of allergy (cutaneous or systemic), hypersensitivity, or asthma to any of the following: diclofenac, paracetamol, acetylsalicylic acid, salicylic acid, other NSAID or cyclooxygenase 2-specific inhibitor (COXIB) or known intolerance (cutaneous or systemic) to any of the ingredients in the gel, such as isopropyl alcohol or propylene glycol. * History of known narcotic, analgesic, or alcohol abuse. * Any cognitive impairment that would, in the opinion of the Investigator, preclude study participation or compliance with study procedures (e.g., Alzheimer's dementia). * Previously received an investigational product within 30 days before the scheduled dose of study medication.