The primary objective of this clinical trial is to evaluate the efficacy and safety of a topical Urtica dioica cataplasm in managing knee pain and functional limitations in athletic children diagnosed with Osgood-Schlatter Disease. Efficacy will be assessed through changes in knee pain using the Visual Analog Scale (VAS) and functional outcomes using the Knee Injury and Osteoarthritis Outcome Score (KOOS). Three groups will be tested:
* UDC Group: topical application of Urtica dioica cataplasm * Standard Care Group: oral vitamin D supplementation and physical rest * Placebo Group: topical application of a placebo cataplasm using Beta vulgaris subsp. cicla
Healthy male children between 7 and 15 years of age
Active in regular sports practice (e.g., football)
Clinically confirmed diagnosis of OSD
Known allergy to Urtica dioica
Presence of dermatological conditions or lesions on the knees
Recent use of anti-inflammatory medications
History of immune or chronic inflammatory diseases