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

Context: Current recovery guidelines following sport-related concussion (SRC) include 24-48 hours of rest followed by gradual return-to-activity with heart rate (HR) maintained below symptom threshold. Additionally, the monitoring of physical activity (PA) post-SRC using ActiGraph accelerometers can provide further objective insight on amounts of activity associated with recovery trajectories. Cut-point algorithms for these devices allow minute-by-minute PA to be classified into intensity domains; however, studies have shown different algorithms employed on the same healthy participant dataset can produce varying classifications.

Objective: To identify the most physiologically appropriate cut-point algorithm (Evenson or Romanzini) to analyze ActiGraph data in concussed youth with comparisons to HR response on the Buffalo Concussion Treadmill Test (BCTT).

Design: Prospective cohort study.

Setting: Sport-concussion clinic within a university setting.

Patients or other participants: Eleven high-school students (5 male, 6 female; median [range] age =16 years [15-17], height = 177.8 cm [157.5-198.1], weight = 67 kg [52-98], body mass index = 22 kg/m2 [17-31]) involved in high-risk sport 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: There were differences in moderate (P = .001) and vigorous (P = .002) intensities between algorithms, but no difference in light (P = .548). Evenson classified most of the time as moderate intensity (57.03% [0.00-94.12%]), whereas Romanzini classified virtually all PA as vigorous (88.25% [2.94-97.06%]). PA based on HR (stages 1-7: 20-39% HR reserve (HRR), stages 8-13: 40-59% HRR, stages 14 and above: 60-85% HRR) indicated the BCTT primarily involves light-to-moderate intensity, and therefore is better represented by the Evenson algorithm.

Conclusions: The Evenson algorithm better characterizes the HR response during a standardized exercise test in concussed individuals and therefore should be used to analyze ActiGraph PA data in a concussed paediatric population.