CTE is linked to repetitive head hits. Not just concussive hits but routine subconcussive impacts. The brain simply is not designed to be rattled on a repeated basis.
If you are a competitive full contact fighter getting hit in the head during a bout is inevitable. Its part of the trade.
Sparring is an important training method for competition where some level of head impacts will also occur. A fundamental question, however, is how much head trauma is needed in training appreciating that every hit counts in the toll they could take on brain health? A recent study was published shedding light on how many head hits some athletes are taking in training. The short answer is a lot.
The study, titled Characterizing Head Impact Exposure in Men and Women During Boxing and Mixed Martial Arts was published by the Cleveland Clinic as part of their ongoing investigation of professional fighter brain health. In it they followed 23 athlete (comprised of male and female boxers and mixed marital artists). They were fitted with impact monitoring mouthpieces. Sparring and competition footage was reviewed and then cross referenced with recorded impacts to verify the integrity of the measurements. The data revealed that while the intensity/severity of impacts recorded during competition were far stronger the volume of registered head hits athletes had simply training were 10x greater.
Addressing this the authors noted as follows:
“The accumulation of subconcussive impacts has been implicated in permanent neurological impairment…
A total of 896 head impacts were identified using IMM data and video verification: 827 in practice and 69 during competition. MMA and boxers experienced a comparable number of impacts per practice session or competition. In general, MMA impacts produced significantly higher peak angular acceleration than did boxing impacts (P < .001) and were more varied in impact location on the head during competitions. In terms of sex, men experienced a greater number of impacts than women per practice session. However, there was no significant difference between men and women in terms of impact magnitude.“
The full abstract reads as follows:
Background: The accumulation of subconcussive impacts has been implicated in permanent neurological impairment. A gap in understanding the relationship between head impacts and neurological function is the lack of precise characterization and quantification of forces that individuals experience during sports training and competition.
Purpose: To characterize impact exposure during training and competition among male and female athletes participating in boxing and mixed martial arts (MMA) via an instrumented custom-fit Impact Monitoring Mouthguard (IMM).
Study Design: Cross-sectional study; Level of evidence, 3
Methods: Twenty-three athletes (n ¼ 4 women) were provided a custom-fit IMM. The IMM monitored impacts during sparring and competition. All training and competition sessions were videotaped. Video and IMM data were synchronized for post hoc data verification of true positives and substantiation of impact location. IMM data were collected from boxing and MMA athletes at a collaborating site. For each true-positive impact, peak linear acceleration and peak angular acceleration were calculated. Wilcoxon rank sum tests were used to evaluate potential differences in sport, activity type, and sex with respect to each outcome. Differences in impact location were assessed via Kruskal-Wallis tests.
Results: IMM data were collected from 53 amateur training sessions and 6 competitions (session range, 5-20 minutes). A total of 896 head impacts (men, n ¼ 786; women, n ¼ 110) were identified using IMM data and video verification: 827 in practice and 69 during competition. MMA and boxers experienced a comparable number of impacts per practice session or competition. In general, MMA impacts produced significantly higher peak angular acceleration than did boxing impacts (P < .001) and were more varied in impact location on the head during competitions. In terms of sex, men experienced a greater number of impacts than women per practice session. However, there was no significant difference between men and women in terms of impact magnitude.
Conclusion: Characteristic profiles of head impact exposure differed between boxing and MMA athletes; however, the impact magnitudes were not significantly different for male and female athletes.
Combat Sports Law 