Objective To use ecologic momentary assessment to measure and compare daily reports of physical/cognitive activity and symptoms among youth for 2 weeks after sustaining a concussion.

Design Prospective cohort study, with patients reporting to random prompts on a handheld 3 times daily and wearing an accelerometer.

Setting Specialty concussion program within a large regional paediatric healthcare network.

Participants 34 patients, ages 11–17 years with the diagnosis of concussion seen in the concussion program.

Independent variables Measurements of daily physical activity (step count) and cognitive activity (composite score of texts sent, screen time minutes, reading minutes, school attendance).

Outcome measures Daily symptoms on the Post Concussion Symptom Scale (PCSS).

Main results Study subjects were enrolled a median of 6 days post-injury (range 5–13 days). Numerous profiles were observed, including being initially highly (PSCC≥20) or less symptomatic (PSCC ≤ 10), initially highly (steps>6000) or less physically active (steps<3000), and initially highly or less cognitively active. Levels of activity also varied greatly over follow-up. Symptoms declined in most subjects regardless of activity levels during follow-up. Regardless of activity levels, most patients were not symptomatic (PCSS ≤ 8) at the end of the follow-up period.

Conclusions We found evidence that initial levels of physical and cognitive rest vary greatly in the days immediately following a first visit, and over subsequent weeks, but most patients were asymptomatic after 4 weeks from injury. This protocol can be used in larger studies designed to fully test whether and how physical and cognitive rest and their timing following injury affect recovery.

Competing interests None.