Abstract
Background:
Wrestling is a popular combative sport with relatively high injury rates to the head and neck(1). While concussion rates have been studied in male wrestlers(2), head acceleration data have only been reported in males(3) and females(4) separately, and never compared. No studies have examined head impact exposure during practices, where repetitive impacts may accumulate. This study investigated sex differences in head impact frequency and kinematics during varsity wrestling practices.
Hypothesis:
Female wrestlers sustain more and greater-magnitude head impacts than males.
Methods:
This prospective cohort study involved a convenience sample of varsity wrestlers who wore custom-fit instrumented mouthguards (Prevent Biometrics) during practices, which recorded head accelerations exceeding 5g (where g = 9.81m/s²) over a 50ms time window. Practices were video recorded using three tripod-mounted iPads positioned to capture multiple angles. Mouthguard data were timestamped and synchronized with video. Head impacts were defined as events exceeding 20g linear or 2000rad/s² rotational acceleration to prioritize biomechanically relevant events, enable feasible video verification, and highlight high-severity impacts for prevention efforts. Head impacts were video-verified and contextualized using Dartfish, with maneuver and positional context (offense, defense, or neutral) identified for each. A Poisson regression (with exposure hour offset) compared overall impact rates. A generalized linear mixed-effects model (Poisson distribution; player as random intercept) examined impact frequency by sex, maneuver, and positioning. Peak head accelerations were compared using a linear mixed-effects model.
Results:
Twelve wrestlers (6 female; ages 18-23) wore mouthguards during seven practices (57 athlete exposures, 114 hours). A total of 122 video-verified head impacts exceeded the acceleration thresholds. Female wrestlers experienced 85 impacts over 62 hours (1371 per 1000 player-hours, 95%CI: 1095-1695), while males experienced 37 impacts over 52 hours (712 per 1000 player-hours, 95%CI: 501-981), corresponding to a 1.93-fold higher head impact rate in females (95%CI: 1.32–2.87). Compared to defensive positioning, neutral positioning was associated with a nearly 10-fold increase in head impacts for females (IRR = 9.93, 95%CI: 2.30-42.86, p=0.002), and a 3.5-fold increase for males (IRR = 3.51, 95%CI: 0.66-18.67, p=0.042). There were no statistically significant sex differences in peak head acceleration measures.
Conclusion:
Female wrestlers experienced higher head impact rates than males during practice. Females’ elevated impact frequency, particularly during neutral positioning when athletes are vying for position, highlights a potential sex-based disparity in head impact exposure. These findings emphasize the importance of identifying sex- and maneuver-specific mechanisms of impact to guide targeted strategies aimed at reducing concussion risk in wrestling.