1. Introduction
Mixed martial arts (MMA) is a relatively young combat sport, but its high popularity warrants special attention. Although MMA was established around the 1990s, it has rapidly gained a high number of practitioners of all ages as well as fans worldwide, with new injuries and psychosocial consequences emerging [
1,
2,
3]. During the fight, various techniques are allowed, which constitutes a discipline with a high risk of different types of injury [
1,
4,
5,
6,
7]. According to Ross et al. [
1], in 57% of MMA fights, athletes sustain at least one injury. The injury rate is higher in professional fights than in amateur fights—68% to 51%. According to a meta-analysis of MMA injuries, the region most at risk is the head (66.8–78.0%), followed by wrist and hand (6.0–12.0%) [
7]. The risk of head trauma and concussion has been a subject of many reports in the literature [
8,
9,
10,
11]. However, there is a limited number of studies concerning the risks associated with the submission techniques in this combat sport. During submission, a fighter is exposed to a technique causing serious pain or discomfort and decides that they cannot withstand it any longer. Most submission techniques concentrate on joints causing injury or the neck to choke the opponent. A survey study conducted among Brazilian jiu-jitsu (BJJ) fighters states that 60% of them are injured during competitions [
12]. The primary reported injuries were sprains and strains to the fingers, upper extremities, and neck. Grappling and submission techniques from BJJ are allowed in MMA fights.
Analysis of fight results and comparison between weight categories is beneficial for creating training strategies and injury prevention plans. Understanding the successful performance in a professional fight is needed for establishing an ideal physiological profile for MMA success. This sport involves intermittent activity with periods of engagement that include both high forces and high-velocity actions [
13]. Fights are scheduled for three to five rounds, each lasting five minutes. Combining both striking and grappling techniques involves different physiological requirements for the athlete—high isometric and dynamic strength is needed for grappling, while for striking, a rapid expression of force is required [
14]. The evaluation of submissions ending professional MMA fights may provide insight into the potential successful fight profile in this discipline—both in terms of sports performance and athletes’ safety. Additionally, the inclusion of female fighters in the evaluation is necessary—most previous studies have focused solely on males, and potential gender differences have not been adequately considered. The winning strategies in combat sports are often closely tied to injuries; thus, the aim of this research was to calculate the number of different submission techniques that ends fights in professional mixed martial arts matches and estimate the risk associated with them.
3. Results
There were 2488 fights included in the evaluation—169 female fights and 2319 male. Fights were scheduled for three to five rounds, with a longer duration for the title fight. Notably, fight times differed significantly between female bouts (
n = 169; M = 12 min 5 s; SD = 6 min 16 s) and male bouts (
n = 2319; M = 10 min 27 s; SD = 6 min 11 s; Mann–Whitney’s U = 225,230,
p < 0.001)—female fights were on average one and a half minutes longer. In addition to duration, outcomes also differed statistically between male and female fights (
Table 1, Chi
2(3) = 11.83,
p = 0.008). Specifically, women’s fights were relatively more likely to end due to a split decision or unanimous decision, and less likely to end in a knockout or technical knockout. Finally, the 17 men’s fights with the fewest reasons for stoppage (majority decision: 6 fights; disqualification: 10 fights; technical decision: 1 fight) were omitted from the analyses.
Fight results statistically significantly different between title fights and non-title fights (
Table 2, Chi
2(3) = 15.41,
p = 0.001). There were relatively more endings due to KO/TKO in title fights than in non-title fights.
Table 3 shows the relationship between fight results and weight categories. Due to the low numbers of catchweight and women’s featherweight fights, these categories were not included in the comparison.
Fight results differed among weight categories. The greatest variation occurred in the frequency of fight stoppage by KO/TKO, with an average of 36% of fights being terminated in this manner, and percentages ranging from 18% in the flyweight to 45% in the light heavyweight division. In contrast, the percentages of fights ended by submission and by split decision were more similar. For submissions, the average was 19% with ranging from 9% in the featherweight to 23–24% in the middleweight and welterweight categories. Split decision endings ranged from 0% in the women’s featherweight to 18% in the women’s bantamweight category. Unanimous decision rates varied as well, from 23% in the heavyweight category to 50–53% in catchweight, featherweight, and women’s flyweight categories.
To further examine these relationships, an additional analysis of weight category and fight results in men’s fight was conducted using a rang correlation analysis. Results showed that the lower the weight limit in a category, the more frequent fight ending due to unanimous decision (rS(8) = −0.98 ***, p < 0.001) and split decision (rS(8) = −0.80 ***, p = 0.018), while interruptions due to KO were less frequent (rS(8) = 0.92 ***, p < 0.001). The frequency of fight stoppage by submission was unrelated to weight category (rS(8) = −0.08, p = 0.844).
Table 4 presents the proportion of title fights and non-title fights in the analyzed database, categorized by the gender of the athletes. The proportion of title fights and other fights differed significantly between male and female fighters (Chi
2(1) = 17.90,
p < 0.001).
Fight durations differed between weight categories (
Table 5; Kruskal–Wallis = 106.96,
p < 0.001). Specifically, fight times in the heaviest categories—heavyweight and light heavyweight were significantly shorter than those in most other categories. Furthermore, a weak but statistically significant relationship was found—the higher the weight category in the men’s divisions, the shorter the fight time (rS(4604) = −0.19 ***,
p < 0.001). In contrast, an analogous relationship did not occur in women’s bouts (rS(338) = −0.11,
p = 0.051).
The duration of fights terminated due to submission was also evaluated. Analyses were conducted for two indicators: the number of rounds and the duration of the fight (in seconds). The majority of fights ended by submission were one-round (
Table 6; 52.20%), followed by two-round fights (30.30%), and then three-round fights (15.60%). The percentages of fights completed by submission with each number of rounds were not statistically significantly different between men’s fights and women’s fights (Chi
2(4) = 4.53,
p = 0.339). Men’s and women’s fights completed by submission were not statistically significantly different in duration (men’s fights: M = 6 min 9 s, SD = 4 min 17 s; women’s fights: M = 6 min 35 s, SD = 5 min 3 s, U = 6789,
p = 0.662).
Title fights lasted more rounds than non-title fights (
Table 7; Chi
2(4) = 89.26,
p < 0.001)—among title fights ended by submission, relatively fewer fights than non-title fights were ended in the first and third rounds. Title fights ended by submission were longer (M = 9 min 27 s, SD = 6 min 23 s) than non-title fights (M = 5 min 49 s, SD = 3 min 44 s; U = 12,552.5,
p < 0.001).
Table 8 shows the percentages of fights ended by submission in a given number of rounds by weight category of fighters. Due to the low number of fights ended by submission in some weight categories and in a portion of rounds, it was not possible to conduct a formal analysis of the differences between weight categories in terms of the number of rounds in which fights were ended by submission.
Table 9 presents the durations of fights ended by submission, categorized by according to weight category. These times were not statistically significantly different between weight categories (U = 18.652,
p = 0.097).
The fight control time was compared between fighters who won the fight and those who lost the fight. Fighters who won the fight controlled the fight for an average of 193.8 s (3 min 14 s; SD = 3 min 34 s), while fighters who lost the fight controlled the fight for 82 s (1 min and 22 s; SD = 1 min 55 s). The difference in fight control time was statistically significant (t(4974) = 22.94,
p < 0.001). The same difference occurred in men’s bouts (F1: M = 3 min 15 s, SD = 3 min 36 s; F2: M = 1 min 21 s, SD = 1 min 54 s; t(4636) = 22.57,
p < 0.001), and in women’s bouts (F1: M = 3 min, SD = 3 min 13 s; F2: M = 1 min 42 s, SD = 2 min 9 s; t(336) = 4.36,
p < 0.001). The control time of the fight, categorized by weight and whether the fighter won or lost, was analyzed using a two-factor analysis of variance (category × fighter) (
Table 10). The analysis found a significant effect of weight category (F (94,487) = 4.01,
p < 0.001), a significant effect of fighter (F (14,847) = 264.44,
p < 0.001), and a significant effect of the interaction of fighter and weight category (F (94,847) = 3.24,
p < 0.001). Post hoc analyses showed that fight control time by athletes was significantly longer in the welterweight category than in the bantamweight, heavyweight, and light heavyweight categories. Differences in fight control time between athletes were greatest in the flyweight and welterweight categories.
Table 11 includes all submission techniques ending fights in different weight categories, with a calculation of the total occurrence in the analyzed fights. The most common submission technique was rear-naked choke, which ended 154 fights. Others that occurred repetitively included guillotine choke—89, armbar—63, triangle choke—35, arm triangle—26, and kimura—21 fights. For further analysis, 462 fights were selected due to the submission by different types of chokeholds or techniques concentrating on the hand or arm. A total of 317 fights were ended by chokes (68.6% of fights ended by submission), and 125 fights were ended by hand/arm techniques (27.1% of fights ended by submission) (
Table 11). In men’s fights, 69.9% of fights ended by submission were ended by chokes, and 25.5% of fights ended by hand/arm techniques. In women’s fights, both fights ended by chokes and fights ended by hand/arm techniques were 50% of all fights ended by submission. The differences between the groups were statistically significant—significantly more male fights were ended by chokes (Chi
2(1) = 5.16,
p = 0.023), and significantly more female fights were ended by hand/arm techniques (Chi
2(1) = 18.39,
p < 0.001). In title fights, fights ended by chokes accounted for 66.7% of fights ended by submission, while fights ended by hand/arm techniques made up 33.3% of fights ended by submission. In non-title fights, those ended by chokes were 68.8% of fights ended by submission, and fights ended by hand/arm techniques accounted for 26.4%. The differences between the title fights and the other fights were not statistically significant (chokes: Chi
2(1) = 0.088,
p = 0.767; hand/arm techniques: Chi
2(1) = 0.995,
p = 0.318).
Table 12 presents the percentages of fights ended by chokes and hand/arm techniques categorized by weight. Some weight categories were excluded from the analysis due to a small number of submissions by chokeholds or hand/arm techniques.
The number of submission attempts was compared between the sexes. Women’s fights had significantly fewer submission attempts (M = 0.32, SD = 0.71,
n = 338) than men’s fights (M = 0.45, SD = 0.91,
n = 4638; U = 738,803.5,
p = 0.023). Similar gender differences were not found when the sexes were compared within the same weight category. The number of submission attempts differed significantly between weight categories (
Table 12; U = 52.43,
p < 0.001). Statistically significant differences were found for pairs: light heavyweight–welterweight (adjusted
p = 0.001); light heavyweight–middleweight (adjusted
p = 0.003); light heavyweight–lightweight (adjusted
p < 0.001); heavyweight–welterweight (adjusted
p = 0.034); heavyweight–lightweight (adjusted
p = 0.002). No linear relationship was found between the weight limit in a category and the number of submission attempts (rS(4942) = −0.03,
p = 0.077) (
Table 12).
The percentage of defended takedowns was also compared between the sexes. Women’s fights (M = 28.4%, SD = 36.7%,
n = 338) did not differ significantly in the percentage of defended takedowns from men’s fights (M = 27.5%, SD = 36.3%,
n = 4638; U = 793,157.5,
p = 0.690). No differences were also found within any of the weight categories. No differences were found in terms of the percentage of defended takedowns between title fights (M = 24.8%, SD = 34.8%,
n = 522) and other fights (M = 27.9%, SD = 36.5%,
n = 4454, U = 1,121,163,
p = 0.147). The percentage of defended takedowns differed significantly between weight categories (
Table 13; U = 23.49,
p = 0.024). Despite the significant category effect, no differences were found between pairs of weight categories. There was also no clear linear relationship between the weight limit in a category and the percentage of defended brings (rS(4942) = −0.04,
p = 0.003).
4. Discussion
The length of fight time to submission finish remains consistent across all weight divisions. Fighters in the heaviest categories experienced significantly shorter fights compared to those in lighter weight classes. A weak but statistically significant negative correlation was observed between the weight limit of a category and fight duration in men, indicating that the heavier the weight category, the shorter the fight time. However, while this pattern did not reach significance in women, a gender-based comparison revealed that female bouts were approximately one and a half minutes longer on average than male bouts, and women’s fights had significantly fewer submission attempts compared to men’s fights. Specifically, women recorded an average of 0.32 submission attempts, compared to men’s average of 0.45 submission attempts. Fewer submission attempts might indicate a different approach or fighting style, possibly reducing cumulative exposure to the dangerous grip or chokehold techniques. On the other hand, even infrequent but high-risk moves can result in serious injuries, highlighting the importance of training fighters in safe practice techniques and effective defense against submissions. However, when examining submission attempts within the same weight category, these gender differences were not observed, indicating that factors related to weight class play a role in the frequency of submission techniques used. Both the fighter’s characteristics and the assigned weight class influence the way fights progress and the outcomes regarding submissions and overall duration. Most submissions occurred in the first round of the fight, which accounted for 52.20% of the cases.
The most common submission technique in evaluated fights was a rear-naked choke. 68.6% of all submissions were caused by chokes, more frequently in male than female fights. Similar results were presented by Stellpflug et al. [
15], who analyzed all fight-ending chokes in the UFC. During the evaluated period, there were 904 chokes, which ended 15.5% of fights, making it the most common submission technique—76.2%. Most chokes were ended by voluntary stoppage by a fighter, but 11% of them resulted in loss of consciousness. Neck compression used to end a fight involves squeezing the carotid arteries and the jugular veins to lower cerebral perfusion pressure and reduce blood flow to the brain [
16,
17,
18]. On average, after ten seconds of such constrictions, the fighter loses consciousness. Sportive chokes are considered safe, especially when surveying the fighters themselves [
19]. However, safety precautions are necessary as there were dangers connected to chokes in combat sports reported [
20]. Hubbard et al. [
20] stated that near chokes, chokes, and submission holds in MMA may result in temporary anoxic brain injury leading to similar changes that occur during a concussive injury. High incidence of chokes and submission by this type of technique should be considered in the care plan of MMA athletes.
The types of injuries sustained in mixed martial arts depend on the techniques allowed during a competition. A prospective study on various combat sports participants showed that those training in wrestling had high rates of joint injuries [
21]. Many studies show that while striking techniques lead to head and facial trauma, submission techniques are detrimental to joints [
22,
23,
24,
25]. A study evaluating the incidence of injury in BJJ competitions shows that there are 9.2 injuries per 1000 exposures, and the most common are orthopedic ones—78% of all [
25]. The most frequently injured joint during submission techniques is the elbow, with the hyperextension injury due to armbar being the most common mechanism. In our study, arm- and hand-concentrated submission techniques, including armbar, accounted for 27.1% of submissions. The armbar caused the end of 63 out of all evaluated fights. The injury rates in MMA are estimated to be 236–286 per 1000 athlete-exposure hours—higher than in BJJ [
4,
26]. The observational cohort study of MMA competitions showed that the most common injuries were abrasions, lacerations, and concussions [
26]. There were, however, 11 orthopedic injuries noted among 232 exposures. Most MMA competition ends with a decision or submission [
4]. The athletes’ and referees’ cautiousness and knowledge about the risk of sustaining an injury during the submission attempts should be considered as crucial preventive measures. Additionally, flexibility, balance, and stability training are crucial for preventing grappling injury [
27].
Although extensive research has been conducted on the injury type in MMA and BJJ, there is still not enough knowledge about the mechanism connected with specific submission techniques [
28,
29]. While studies report general injury rates and common anatomical sites, only a few of them provide detailed information. The injury preventive methods include education aiming at increasing awareness and medical supervision [
30,
31,
32]. However, there is still a lack of sufficient knowledge among the athletes, and some techniques perceived as low risk, such as chokeholds, have been reported in case reports of severe vascular injuries, including cervical artery dissections and ischemic strokes [
30,
31,
33]. The armlock, a technique where forced hyperextension of the elbow is applied using the hip as a pivot and body weight a leverage, has been reported to cause flexor pronator mass injury, medial collateral ligament tears, mild edema, and capsule irregularities [
34]. There has also been cerebral infarct with complete occlusion of the vertebral artery secondary to dissection reported as grappling injury in MMA [
35]. Recurrent takedowns and submission techniques may also lead to cumulative joint stress and thus it is important to discuss standardized injury prevention protocols.
The strong point of the presented research is that it included a high number of fights, and it is the first study to include both professional male and female fighters. Comparing different fight characteristics between weight categories was also a strong feature of the conducted study. However, in some aspects of the research, female fights and certain weight classes could not be considered in the evaluation due to the lower number of participants, which would have led to mistakes in statistical interpretation. Further evaluation of these groups in a higher number of fights would be beneficial in the future. Among the limitations, it also worth noting that the retrospective nature of this evaluation may not provide sufficient information. Although the submission technique that led to the end of the fight was evaluated and verified, it is worth noting that the final technique may not be the most crucial factor in determining the fight result. Through retrospective analysis, we may only suspect that it had the greatest influence on the outcome. The methodology applied in this study assumes an association between fight termination by submission and the risk of injury, without a subsequent assessment of the percentage of fights that resulted in an injury. Due to this aspect, conducting further prospective clinical research to evaluate the incidence of injuries among fighters, including direct clinical injury data, diagnosis, and outcomes, should be considered.