Iselin disease is a uncommon cause of ache on the lateral side of the feet in youths and teenagers. This condition is an osteochondral disorder or traction apophysitis in the base of the fifth metatarsal bone metatarsal. The peroneal brevis tendon connects on the area and puts the metatarsal with a lot of stress. https://podiatrynewyorkcity.com/iselins-disease-of-the-fifth-metatarsal/