Effects of Blast Overpressure

Warfighters, especially those in Special Operations Forces, can experience repeated subconcussive blast exposures (RSCBE) when using high explosives and heavy weapon systems. The Investigating Training Associated Blast Pathology (INVICTA) study assesses the short and long-term effects RSCBE has on brain structure and function in Navy SEALs heavy weapon trainees, Range Safety Officers (RSOs), and active duty Navy controls.

With permission from Naval Special Warfare Command’s leadership, INVICTA is conducted during Navy SEAL Qualification Training and Unit Level Training. Detailed baseline assessments are conducted prior to heavy weapons training, with subsequent assessments through three months for SEALs, and two years for RSOs.

INVICTA utilizes blast monitoring devices to measure and record each exposure. Data from these devices will be paired with results from the study’s cognitive (e.g., memory, attention), physiological (e.g., blood, EEG) and functional (e.g., balance, vision, hearing) tests to generate a comprehensive assessment on the brain’s response to RSCBE.

Additional information about the INVICTA study is detailed in the table below. Inquiries should be directed to INVICTA@usuhs.edu.

In the future, similar evaluations and assessments are planned for Explosive Ordnance Disposal (EOD) personnel across all U.S. Armed Forces. Warfighters in this particular community have unique and frequent exposures to blasts and psychological stressors throughout their careers.








Investigating Training Associated Blast Pathology (INVICTA)

Michael Roy: MD, MPH, COL (Ret) USA, Uniformed Services University

Co-Principal Investigators

David Keyser: PhD, Uniformed Services University

Walter Carr: PhD, MAJ (Ret), USA, Walter Reed Army Institute of Research

  • Conduct detailed baseline assessments prior to heavy weapons training.
  • Use monitoring devices to measure and record blast overpressure exposures 

Conduct various assessments at acute, subacute, and chronic time points to measure cognitive, physiological, and functional outcomes 

Identify biomarkers that best indicate the impact RSCBE has on brain structure and function

Naval Special Warfare heavy weapons training participants (e.g., trainees and instructors) and active duty Navy controls