Laboratory Validation of Two Wearable Sensor Systems for Measuring Head Impact Severity in Football Players

Ann Biomed Eng. 2016 Apr;44(4):1257-74. doi: 10.1007/s10439-015-1420-6. Epub 2015 Aug 13.


Wearable sensors can measure head impact frequency and magnitude in football players. Our goal was to quantify the impact detection rate and validity of the direction and peak kinematics of two wearable sensors: a helmet system (HITS) and a mouthguard system (X2). Using a linear impactor, modified Hybrid-III headform and one helmet model, we conducted 16 impacts for each system at 12 helmet sites and 5 speeds (3.6-11.2 m/s) (N = 896 tests). Peak linear and angular accelerations (PLA, PAA), head injury criteria (HIC) and impact directions from each device were compared to reference sensors in the headform. Both sensors detected ~96% of impacts. Median angular errors for impact directions were 34° for HITS and 16° for X2. PLA, PAA and HIC were simultaneously valid at 2 sites for HITS (side, oblique) and one site for X2 (side). At least one kinematic parameter was valid at 2 and 7 other sites for HITS and X2 respectively. Median relative errors for PLA were 7% for HITS and -7% for X2. Although sensor validity may differ for other helmets and headforms, our analyses show that data generated by these two sensors need careful interpretation.

Keywords: Acceleration; Concussion; Football; Head impact; Validity; Wearable sensors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acceleration
  • Biomechanical Phenomena
  • Craniocerebral Trauma
  • Football / injuries
  • Football / physiology*
  • Head Movements / physiology*
  • Head Protective Devices*
  • Humans
  • Laboratories
  • Mouth Protectors*
  • Reproducibility of Results
  • Telemetry / instrumentation*