Activity Level During Acute Concussion May Predict Symptom Recovery Within an Active Duty Military Population

OBJECTIVE: To evaluate the impact on symptom resolution of activity acutely following a concussion and the role of acute-phase symptoms on this relationship among active duty service members (SMs). SETTING: Three military installations. PARTICIPANTS: Sixty-two SMs aged 18 to 44 years who sustained a concussion within 72 hours of enrollment. DESIGN: Longitudinal design with data collected within 72 hours of injury (baseline, n = 62) and at 1 week (n = 57), 1 month (n = 50), 3 months (n = 41), and 6 months (n = 40) postinjury. MAIN MEASURES: Baseline activity level using a 60-item Activity Questionnaire. Symptom level at baseline and during follow-up using Neurobehavioral Symptoms Inventory. RESULTS: Significant interaction (Pi < .05) was found, with significant main effects (P < .05) limited to SMs with elevated baseline symptomatology. Among these participants, greater baseline total activity was significantly related to greater vestibular symptoms at 1, 3, and 6 months (beta = .61, .63, and .59, respectively). Significant associations were also found for particular types of baseline activity (eg, physical; vestibular/balance; military-specific) and symptoms at 1, 3, and/or 6 months postinjury. CONCLUSION: These results provide support for clinical guidance that symptomatic SMs, particularly those with high levels of acute symptoms, may need to avoid excessive activity acutely following concussion.