Berntsen KS, Raastad T, Marstein H, et al. - In this cross-sectional study (n = 44 individuals and 44 age/gender-matched controls), experts intended to contrast muscle strength/endurance of knee extensors between individuals with long-term juvenile dermatomyositis (JDM) and controls, and between people with active and inactive disease. and in patients to investigate relationships between strength/endurance and clinical parameters, physical activity, and humoral/structural adaptation in skeletal muscle. In long-term JDM vs controls and in the active compared with inactive disease, muscle strength/endurance of knee extensors was lower. Results designate a requirement for more sensitive muscle tests in this clinical setting. Thus, it was hypothesized that in the active disease, impaired muscular endurance may be affected by structural/functional adaptations of muscle tissue irrespective of muscle size.