Juvenile-onset fibromyalgia (JFM) is a chronic condition characterized by widespread musculoskeletal pain. For adolescents with fibromyalgia, existing treatments can provide acute pain relief but rarely result in long-term pain resolution. Long-term pain contributes to a reduction in physical activity that can propagate to dysfunctional motor behavior and further deconditioning. The six-minute walk test (6MWT) is commonly used to evaluate functional ability in JFM; however, the most frequently used outcome measure—total distance traversed—is unable to provide spatiotemporal characterizations of motor behavior (i.e., coordination) during the test. In order to capture the effect of repetitive movement dynamics on motor coordination, pain, and fatigue in JFM, the current pilot study utilized a high-definition, 42-camera motion capture system (Motion Analysis Corp., Santa Rosa, CA) to track participants' (n = 8) movements in three-dimensional space along a 15.0m walkway during the 6MWT. Gait speed and coordination dynamics were quantified from the lower-extremity markers across the 6MWT and were further split into three 2-minute sections for comparison (i.e., 0-120 seconds, 120-240 seconds, and 240-360 seconds). Pain and fatigue ratings (1 to 10 scale) were assessed pre- and post-6MWT. Participants reported higher pain and fatigue ratings after the 6MWT (both p's < .05) concomitant with poorer coordination dynamics and reduced gait velocity in the early versus late test testing sections. These data indicate that pain and fatigue are related to altered coordination dynamics during daily motor tasks in adolescents with JFM and contribute to fear of pain and increasing avoidance of physical activity. Funding: R01AR070474 and PORTICO Center (P30AR076316).