Locomotor parameters in the different treatment groups over time. (A) Limping score. (B) Range of motion (ROM) in the inflamed ipsilateral knee joint. (C) ROM in the noninflamed contralateral knee joint. Data are presented as means ± SEM. *Differences between saline and dexamethasone. §Differences between saline and morphine. +Differences between morphine and dexamethasone. Differences between immunized controls and the treatment groups are not presented. *P < 0.05; **P < 0.01; ***P < 0.001. AIA: antigen-induced arthritis.