Nociceptive and Inflammatory Evaluation of Water Jumping in Wistar Rats with a Rheumatoid Arthritis Model

Purpose. The aim of this study was to evaluate whether resistance exercise in an aquatic environment promotes the return of peripheral functionality and contributes to reducing leukocyte migration in the knee joint of rats with a model of rheumatoid arthritis (RA). Methods. Forty male rats were divided into four groups: SHAM – Control; RA – Inju­ry Group; SHAMEX – Exercise Group; and RAEX – Injury Group treated with resis­tance exercise. RA was induced by immunization at the base of the tail and intra-artic­ular injection of complete Freund’s adjuvant (CFA) into the tibiofemoral joint of the right knee. The exercise protocol was conducted three times a week in a water tank with an overload of 50% of the animal’s weight for 22 days, gradually increasing the number of sets and repetitions every three sessions. The right hind limbs were evalu­ated for nociception, edema, peripheral function, and synovial infiltrate to analyze the repercussions following the injury in eight assessments. Results. The induction of joint arthritis impaired joint function, but the RAEX group exhibited reduced pain, improved functional capacity, and a decreased presence of inflammatory cells in the synovial fluid. Conclusions. Resistance exercise in an aquatic environment promoted functional improvement of the knee joint in Wistar rats with an RA model.