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Updated: Feb 13, 2026

A Repetitive Concussive Head Injury Model in Mice
Published on: October 12, 2016
Exploring the link between acute symptom changes and repetitive head impacts in boxing sparring
Enora Le Flao1, Gunter P Siegmund2, Seth Lenetsky3
1School of Health & Rehabilitation Sciences, The Ohio State University Wexner Medical Center, USA; Auckland University of Technology, New Zealand.
Objectives:
The acute dose-response relationship between head impact exposure and the development of concussion remains elusive. Previous research has suggested that individual-specific approaches and the cumulative effects of head impacts should be investigated. This study aimed to monitor acute changes in concussion-related symptoms resulting from boxing sparring, and assess how they relate to head impact exposure.
Design:
Observational cohort study.
Methods:
Seven competitive boxers participated in this exploratory study. Symptoms of concussion were captured via the SCAT5 symptom scale upon recruitment, immediately before (PRE), immediately after (POST), and 48 h (48H) after a sparring session. Head impact data were collected with instrumented mouthguards. Each session's mean, median, highest-magnitude impact, cumulative sum, and time-weighted exposure for several injury severity metrics were qualitatively analyzed with respect to acute changes in symptom score.
Results:
Group-based analyses did not show any differences in symptom scores PRE/POST-sparring (median change in total symptom severity score [ΔTSSS]: -1, p = 0.85, r = 0.07). Symptom number and TSSS were significantly lower at 48H compared to PRE (median ΔTSSS: -1, p = 0.02, r = 0.55). Four of 16 sessions (25%) from three participants showed a ΔTSSS >5. There was no strong association between session-specific exposure and change in symptoms, but time-weighted exposure metrics showed a better alignment than other metrics.
Conclusions:
Symptom number and severity PRE/POST sparring changes were rare and subtle, and the link to head impact exposure is unclear. Our exploratory analyses support the concept of individual-specific approaches, as this allowed us to identify patterns emerging from a few athletes that were not visible in cohort-averaged summaries. Understanding the relationships between head impact exposure, individual pre-disposition, and signs and symptoms of concussion is essential to designing risk reduction strategies.
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