Adding to this site’s data base of combat sports safety studies, a recent study was published in the Journal of Physical Fitness and Sports Medicine in Japan reviewing concussions in MMA fighters and their connection to past knockouts.
In the study, titled Incidence of concussions in male mixed martial arts competition in relation to number of matches and previous knockout losses, the authors analyze 104 male MMA fighters who competed in elite level competitions. In their most recent bout 44 were diagnosed with a concussion. The records between the groups was then reviewed. Those that were concussed in their latest bouts were significantly more likely to have been knocked out (ie have a previously recorded concussion) on their record than the non concussed cohort. The odds ratio for the occurrence of concussions in fighters with a history of KO losses was 2.3 times that of fighters without a history of KO losses.
This study gives more data backing the idea that fighters would be wise to avoid hard sparring risking concussions in training. Once concussed an athlete is 6 times more likely to suffer a future concussion. One recent study found that the first athlete to be concussed in pro boxing and MMA loses the bout 98% of the time. A concussion in the gym is just as damaging as a concussion in a fight. Cumulative damage in the gym adds up just as much as damage in a paid bout.
The authors provided the following comments on the tolls of concussions and cumulative sub concussive damage for MMA fighters:
The reason why the concussion rate increases with the number of past KO losses is that almost all KO losses are concussions, and players with many past KO losses are also players with many concussion injuries…
repeated minor impacts from blows to the head with little subjective symptoms may also lead to damage accumulation, in addition to obvious concussions caused by KO losses…The damage caused by head trauma accumulates; and in order for fighters to remain active for a long time and be healthy after retirement, it is necessary to work on a daily basis to minimize head damage and to inform fighters about the importance of care after a KO loss or concussion.
The full abstract reads as follows:
Mixed martial arts (MMA) is a combat sport with a high incidence of concussions, including knockouts (KO) due to direct attacks to the head. Once a concussion occurs in a fighter, the rate of concussion recurrence increases. Therefore, participation in matches may be weakened to head impacts as fighters experience repeated concussions. In this study, we investigated the relationship between the occurrence of concussions in male mixed martial arts athletes during the most recent match and their past match records. The analysis included 104 male fighters who competed in elite-level professional MMA competitions. In the most current match, 44 fighters experienced a concussion and 60 fighters did not. Previous KO losses (mean, 2.9) were significantly higher in the fighters who had experienced a concussion compared to fighters who had not (p < 0.0001). Concussion rates (65.0%) were significantly higher in fighters with three or more previous KO losses compared with the rates for fighters with less than 3 previous KO losses (p = 0.03). The odds ratio for the occurrence of concussions in fighters with a history of KO losses was 2.3 times that of fighters without a history of KO losses (p = 0.004). Fighters who had competed in more than 30 matches had a significantly higher incidence of concussions (60.8%) than fighters who had competed in less than 30 matches (37.0%) (p = 0.04). The occurrence of concussions in male MMA fighters is related to the number of previous KO losses and the number of matches
Combat Sports Law 