Instrumented Mouthguard Decoupling Affects Measured Head Kinematic Accuracy.

Area of Science:

• Biomechanics
• Sports Science
• Injury Prevention

Background:

• Boil-and-bite instrumented mouthguards are used to measure head kinematics in sports impacts.
• These devices aim for accuracy by coupling directly to the skull.
• The impact of decoupling on measurement accuracy is not well understood.

Purpose of the Study:

• To investigate how mouthguard decoupling affects kinematic measurement accuracy during simulated sports impacts.
• To quantify the influence of gap size, impact direction, and duration on measurement error.

Main Methods:

• A boil-and-bite mouthguard was fitted to a 3D-printed headform with sensors at the center of gravity.
• Pendulum impact tests were conducted with varying gap sizes (0, 1.6, 4.8 mm) simulating decoupling.
• Linear acceleration and angular velocity were measured and compared to headform reference data.

Main Results:

• Mouthguard measurement error was significantly influenced by gap size, impact duration, and direction.
• Larger gaps and frontal impacts resulted in higher measurement errors.
• Padded conditions also showed increased errors, and some impacts could not be captured.

Conclusions:

• Decoupling significantly impacts the accuracy of boil-and-bite instrumented mouthguards.
• Researchers must be aware of these limitations and consider advanced post-processing techniques.
• Proper fit and understanding decoupling effects are crucial for reliable head kinematics data.