Accuracy of Instrumented Mouthguards During Direct Jaw Impacts Seen in Boxing

Area of Science:

• Biomechanics
• Sports Medicine
• Injury Prevention

Background:

• Head kinematics measurement is crucial for developing head injury mitigation strategies in contact sports.
• Instrumented mouthguards (iMGs) offer improved solutions for capturing head impact data.
• Validation of iMGs using post-mortem human subjects (PMHS) is limited, despite their superior soft tissue response representation compared to anthropomorphic test devices (ATDs).

Purpose of the Study:

• To evaluate the accuracy of two iMGs, Prevent Biometrics (PRE) and Diversified Technical Systems (DTS), in measuring head kinematics.
• To compare iMG performance against a reference sensor using direct jaw impacts on cadaveric heads.
• To assess the suitability of PMHS for validating iMG technology.

Main Methods:

• Three unembalmed male cadaver heads were fitted with PRE and DTS iMGs.
• Impacts were delivered using hook (4 m/s) and uppercut (3 m/s) punches.
• Kinematic data from iMGs were compared to a reference sensor (REF) attached to the skull base, analyzing metrics like Peak Linear Acceleration, Peak Angular Acceleration, and Head Injury Criterion (HIC).

Main Results:

• The PRE iMG generally underpredicted kinematic data compared to the REF sensor (regression slopes: 0.72–1.04).
• The DTS iMG consistently overpredicted kinematic data (regression slopes: 1.4–8.7).
• Neither iMG fully replicated findings from previous ATD validation studies.

Conclusions:

• The PRE iMG demonstrated closer agreement with the reference sensor than the DTS iMG.
• The study underscores the importance of PMHS for accurate iMG validation due to their realistic biomechanical properties.
• Current iMGs require further refinement for reliable head kinematics measurement in realistic human head impacts.