Effect of joint injections in children with juvenile idiopathic arthritis: evaluation by 3D‐gait analysis

AIM: To investigate how gait patterns change after intra-articular corticosteroid injections (ICIs) in the lower extremities. METHODS: Eighteen children, aged 5-16 y, with juvenile idiopathic arthritis (JIA) and lower extremity involvement participated in the study. Sixty-four joints in the lower extremities were treated with ICIs. The Visual Analogue Scale (VAS, 0-100 mm) was used to assess pain. A 3D motion analysis system and two force plates were used to measure gait parameters, kinematics and kinetics. The first gait analysis was performed before treatment with ICIs, and a second one was done 8-17 d after treatment. RESULTS: The participants' average rating of pain decreased from 26 mm on the VAS before ICI to 11 mm (p = 0.001) after treatment. The self-chosen walking velocity was significantly faster (p = 0.02) after treatment. The range of knee and ankle joint angles during gait increased significantly (p = 0.03 and 0.04) after treatment. At loading response, the hip extension moment increased (p = 0.01) as did knee flexion moment, and plantar flexion moment at pre-swing increased significantly (p = 0.02 and 0.002) after treatment. The ankle also generated more power (p = 0.005) after treatment. CONCLUSION: The study shows positive effects of treatment with ICIs in the lower extremities--especially regarding pain, walking velocity and joint moments. The data indicate that ICI treatment influences the gait pattern also in joints that have not been injected.