Abstract
We examined force, endurance and the electromyographic response to muscle fatigue in ten children with juvenile chronic arthritis (JCA) and ten age-matched healthy controls before and after physical training. Our main finding was a reduced electromyographic response to localized muscle fatigue in the patient group. After training there was a tendency towards a normalized response pattern. A possible explanation may be selective type-II muscle fiber atrophy, and recovery of these fibers after training.