On-field Head Acceleration Exposure Measurement Using Instrumented Mouthguards: Missing Data Imputation for Complete...

Area of Science:

• Sports Medicine
• Biomechanics
• Neurology

Background:

• Accurate quantification of head acceleration events (HAEs) is crucial for understanding brain injury risk in contact sports.
• Missing HAE data is a common challenge in real-world sports research.
• Existing methods may not fully capture the extent of head impacts experienced by athletes.

Purpose of the Study:

• To develop and apply missing data imputation methods for estimating complete head acceleration event (HAE) exposure.
• To quantify the impact of missing data on HAE exposure metrics in university men's ice hockey.
• To improve the accuracy of HAE exposure data for brain injury risk assessment.

Main Methods:

• Collected video and instrumented mouthguard (iMG) data for HAEs over one varsity ice hockey season.
• Utilized a statistical mapping technique to impute missing video-based HAEs from limited camera angles.
• Applied multiple imputation to estimate missing iMG-based HAEs using complete video data.

Main Results:

• 45% of athlete-games lacked recorded iMG data.
• Data imputation increased median per-athlete-season HAE counts by 10% (video) and 69% (iMG).
• Cumulative exposure metrics, including peak linear/angular acceleration and corpus callosum strain, significantly increased post-imputation.

Conclusions:

• Missing HAE data leads to substantial underestimation of athlete exposure and associated brain trauma risks.
• Imputation methods are essential for accurate HAE exposure assessment in sports research.
• This study provides a critical foundation for future research on acute and long-term brain injury risks.