A Standardized Buffalo Concussion Treadmill Test After Sport-Related Concussion in Youth: Do ActiGraph Algorithms Matter?

Abstract

Context: Current guidelines for recovery after sport-related concussion (SRC) recommend 24 to 48 hours of rest, followed by a gradual return to activity with heart rate (HR) maintained below the symptom threshold. In addition, monitoring physical activity (PA) after SRC using ActiGraph accelerometers can provide further objective insight into the amounts of activity associated with recovery trajectories. Cutpoint algorithms for these devices allow minute-by-minute PA to be classified into intensity domains; however, researchers have shown that different algorithms used to evaluate the same healthy participant dataset can produce various classifications. Objective: To identify the more physiologically appropriate cutpoint algorithm (Evenson or Romanzini) to analyze ActiGraph data among concussed adolescents in comparison with their HR responses on the Buffalo Concussion Treadmill Test (BCTT). Design: Prospective cohort study. Setting: University sport concussion clinic. Patients or Other Participants: Eleven high school students (5 boys, 6 girls; median [range] age ¼ 16 years [15–17 years], height ¼ 177.8 cm [157.5–198.1 cm], mass ¼ 67 kg [52–98 kg], body mass index ¼ 22 [17–31]) involved in high-risk sports who sustained a physician-diagnosed SRC. Main Outcome Measure(s): Evenson and Romanzini algorithm PA intensity domains via ActiGraph data and HR during the BCTT. Results: We observed differences in PA time classified as moderate (P ¼ .003) and vigorous (P ¼ .004) intensities between algorithms but no difference in PA time classified as light intensity (P ¼ .48). The Evenson algorithm classified most of the time as moderate-intensity PA (mean ¼ 57.03%, range ¼ 0.00%–94.12%), whereas the Romanzini algorithm classified virtually all PA as vigorous intensity (mean ¼ 88.25%, range ¼ 2.94%–97.06%]). Physical activity based on HR (stages 1–7 ¼ 20%–39% HR reserve [HRR], stages 8–13 ¼ 40%–59% HRR, stages 14 ¼ 60%–85% HRR) indicated the BCTT primarily involved light to moderate intensity and, therefore, was better represented by the Evenson algorithm. Conclusions: The Evenson algorithm better characterized the HR response during a standardized exercise test in concussed individuals and, thus, should be used to analyze ActiGraph PA data in pediatric populations with concussion.