# Mobile Subthreshold Exercise Program for Concussion (M-STEP)

> **NIH NIH R01** · SEATTLE CHILDREN'S HOSPITAL · 2020 · $678,261

## Abstract

Concussion in youth is increasingly being recognized as a national health concern, affecting more than one
million youth each year. As many as 30% of youth with concussion experience persistent and disabling
concussive symptoms lasting more than one month, defined as Persistent Post-Concussive Symptoms
(PPCS). PPCS interferes with social relationships and adversely impacts physical and academic function.
Previous recommendations for treating PPCS focused on cognitive and physical rest, but in 2016 guidelines
shifted based on new research suggesting the benefit of rehabilitative exercise. The rationale behind the use of
exercise is that gradual increases in the intensity of physical activity facilitates return to full function.
Rehabilitative exercise has since become one of the most common approaches to treating youth with PPCS.
However, most programs require weekly centralized visits with a concussion specialist, creating barriers to
care. To bridge this gap, we developed an mHealth approach to treat PPCS, utilizing physical activity trackers
(Fitbits) and weekly video conferences with trained research staff to eliminate the need for frequent clinical
visits. We conducted a series of pilot studies with this approach, finding excellent feasibility, acceptability, and
evidence for more rapid declines in concussive symptoms compared to controls. We also found preliminary
evidence that mechanisms behind this intervention may stem from both physiologic processes due to
increased moderate-to-vigorous physical activity (MVPA) and psychologic processes such as reducing fear-
avoidance of concussive symptoms. We thus propose a fully powered, randomized controlled trial (RCT) to
rigorously examine the “Mobile Subthreshold Exercise Program” (M-STEP) for youth with PPCS. We will recruit
n=250 youth ages 11-18 years with PPCS lasting 1 to 6 months, and randomize them to 6 weeks of either
usual care plus M-STEP (intervention) or usual care plus stretching (control). Youth in M-STEP will be coached
through gradual increases in intensity and duration of rehabilitative exercise via weekly video conferencing
(Zoom) and will use Fitbits to guide their progress. Youth in the stretching group will act as attention controls,
with equivalent study contacts. All youth will complete research-grade measures of MVPA using actigraphy
and standardized surveys at multiple time points. Youth will be followed for a total of 6 months. We will use
mixed effects models to examine differences between experimental groups in the primary outcome, trajectory
of concussive symptoms, and the secondary outcome, changes over time in health-related quality of life, on an
intention-to-treat basis. The proposed transdisciplinary R01 RCT will provide definitive information
regarding the efficacy of M-STEP for youth with PPCS, examine potential mediators including MVPA
and fear-avoidance, and explore the impact of biopsychosocial factors (patient sex and parental
protective behaviors).

## Key facts

- **NIH application ID:** 9967532
- **Project number:** 1R01HD094722-01A1
- **Recipient organization:** SEATTLE CHILDREN'S HOSPITAL
- **Principal Investigator:** Sara P.D. Chrisman
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $678,261
- **Award type:** 1
- **Project period:** 2020-09-08 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9967532

## Citation

> US National Institutes of Health, RePORTER application 9967532, Mobile Subthreshold Exercise Program for Concussion (M-STEP) (1R01HD094722-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9967532. Licensed CC0.

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