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Updated: Sep 8, 2026
A Multi-Modal Approach to Assessing Recovery in Youth Athletes Following Concussion
Published on: September 25, 2014
Feasibility and Clinical Utility of a Modified Step Test for Evaluating Exercise Intolerance After Pediatric and
Matthew F Grady1, Daniele Fedonni2, James Wilkes3
1Center for Injury Research and Prevention, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, and Sports Medicine and Performance Center, Division of Orthopedics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
Background:
Exercise intolerance (EI) is an important component of concussion pathophysiology, serving as a predictor for persisting symptoms, as well as a therapeutic target. It traditionally requires bulky, expensive equipment such as a treadmill to assess.
Purpose:
To evaluate the feasibility of a modified step test to assess EI in youth with concussion and determine its clinical utility for predicting prolonged recovery.
Study Design:
Observational.
Level Of Evidence:
Level 2.
Methods:
A modified step test - an aerobic challenge of 3 to 6 minutes of stepping, targeting zone 2 heartrate (HR, defined as 60% to 70% of maximum HR for age) - assessed patients aged 8 to 18 years with concussion presenting to our concussion specialty program within ≤10 days of injury between August 2022 and July 2025. We defined EI as: (1) major: meeting early stopping criteria (maximum exertion on perceived exertion scale, 85% of age-related maximum HR, increase of ≥3 concussion symptoms from baseline, or patient/parent request to stop), or (2) minor: symptom provocation but below early stopping criteria threshold. Multivariate modeling (1) assessed the odds of EI adjusting for relevant covariates, and (2) determined the influence of EI on prolonged recovery (time in clinical care >28 days), adjusting for factors with known associations with prolonged recovery.
Results:
We included 578 patients. Overall, 366 patients (63%) met criteria for EI, with EI prevalence varying by sex, history of anxiety or depression, and initial symptom burden. In the fully adjusted model, female sex (odds ratio [OR], 1.9; 95% CI, 1.3-2.8), and initial visit symptom burden (OR, 1.05; 95% CI, 1.04-1.06) were associated with EI. Thirty percent of patients (n = 174) demonstrated prolonged recovery. In the multivariate model, major (OR, 1.8; 95% CI, 1.1-3.1) and minor (OR, 2.4; 95% CI, 1.4-4.1) EI were both associated with prolonged recovery.
Conclusion:
This study demonstrates feasibility of identifying EI in youth with concussion via a simple in-office modified step test and the relationship of this measure to prolonged recovery.
Clinical Relevance:
These results have clinical utility for individualizing concussion recovery plans in ambulatory care outside of specialty care settings.
