Efficacy and safety study of diclofenac epolamine topical patch in accelerating rehabilitation of moderate hamstring strain: A randomized controlled trial

Abstract: Background: Moderate hamstring strain is a common sports injury impairing daily and athletic function. While topical nonsteroidal anti-inflammatory drugs (NSAIDs) offer localized pain relief with reduced systemic effects, high-quality evidence specific to hamstring injury is limited. Objectives: To evaluate the effect of a short-course topical diclofenac epolamine patch combined with rehabilitation on pain and functional recovery in moderate hamstring strain. Methods: In this single-center, double-blind, placebo-controlled trial, 120 patients were randomized to an experimental group (diclofenac patch twice daily for 14 days plus rehabilitation) or a control group (placebo patch plus identical rehabilitation). Outcomes assessed included pain measured by the Visual Analogue Scale (VAS), as the primary endpoint, muscle strength, knee range of motion (ROM), functional back-kick test, time to rehabilitation criteria and safety (adverse events, liver/renal function). Results: The diclofenac group demonstrated significantly greater pain reduction at days 14, 21 and 28 post-intervention (all p < 0.01). Muscle strength recovery was superior at days 21 and 28, knee ROM improved more at day 28 and functional back-kick performance was better at day 28 (all p < 0.05). Time to meet rehabilitation criteria was significantly shorter in the experimental group (p = 0.002). Adverse event incidence and changes in liver/renal function were similar between groups (all p > 0.05). Conclusion: A short-course topical diclofenac epolamine patch, combined with rehabilitation training, effectively alleviates pain, accelerates functional recovery, and is safe for treating moderate hamstring strain, supporting its use in clinical and sports rehabilitation.