Share this article on:

Injury Prevention Strategies for Mixed Martial Arts

James, Lachlan P. MSportCoach, MExercSc

Strength & Conditioning Journal: October 2014 - Volume 36 - Issue 5 - p 88–95
doi: 10.1519/SSC.0000000000000086
Article

ABSTRACT THE FULL CONTACT NATURE OF MIXED MARTIAL ARTS GIVES RISE TO A CONSIDERABLE INJURY RISK THAT MUST BE ADDRESSED. THIS ARTICLE IDENTIFIES THE MOST COMMON PREVENTABLE INJURIES IN THE SPORT AND DESCRIBES WHICH ATHLETES MAY BE AT INCREASED RISK. PRACTICAL INTERVENTIONS ARE PROVIDED TO MINIMIZE THE OCCURRENCE OF THESE INJURIES. ADDITIONALLY, METHODS FOR INTEGRATING THESE TASKS INTO A TRAINING PLAN TO INCREASE COMPLIANCE ARE SUGGESTED.

Faculty of Health and Behavioural Sciences, School of Human Movement Studies, University of Queensland, Brisbane, Australia

Conflicts of Interest and Source of Funding: The author reports no conflicts of interest and no source of funding.

Figure

Figure

Lachlan P. James is a PhD candidate at the University of Queensland.

Back to Top | Article Outline

INTRODUCTION

Mixed martial arts (MMA) is a full contact combat sport that incorporates a variety of striking and grappling maneuvers that are found in other martial arts. As is inherent to any combat sport, there is a considerable threat of injury that needs to be addressed by all coaches and athletes. Although nonpreventable injuries predominate MMA competition (35), it is important to consider which preventable injuries are likely to impact the MMA athlete during training and competition. These injuries can then be targeted through training interventions administered by the strength and conditioning coach. The complex nature of MMA, whereby a broad array of techniques are used, leads to the potential for a more varied injury profile than many other sports. Furthermore, it is important to consider that any injury prevention strategies should be targeted toward those competitors at an increased risk of each particular injury (4,25). Adding to the complexity of implementing such a plan is the understanding that poor compliance is often seen in injury prevention programs (39). As such, from a strength and conditioning perspective, these training tasks must be delivered in such a way that minimizes extended training time and does not negatively impact physiological performance markers (23). To address these complexities, this article will discuss the primary injuries that may be encountered by the MMA athlete, in addition to establishing which athletes are at greatest risk. Specific exercises to minimize the incidents of each injury are discussed, along with methods for integrating these activities into a training plan.

Back to Top | Article Outline

INJURY PATTERNS IN MMA

A PubMed Boolean search of the terms “mixed martial arts” and “injuries” returned 20 relevant articles. The earliest publication date was 2005, whereas 11 of the articles were published since 2011. This highlights the recent and rapid growth in popularity of MMA and the increased attention into injury patterns of this sport. Although there is a growing body of data on competition-related injuries, only limited investigation into such trends during training has been undertaken. Determining training-related injuries is crucial as the high volume of training time relative to competition time gives rise to greater opportunity for injury. To assist in determining the common preventable injuries among these athletes, the available epidemiological data will be consulted in addition to close observation of the sport and direct experience with the coaches and athletes themselves. Other combat sports will also be used to guide the determination of these injuries.

After nonpreventable traumas such as bruising and hematomas, Raineir (41) reports that muscle injuries are most common, representing 18.9% of injuries to these athletes in competition and training. Such injuries typically include contusions and strains (26). It would seem intuitive to suggest that nonpreventable contact-related contusions represent a considerable portion of these injuries. However, other muscle injuries such as strains are often preventable. These injuries frequently occur when decelerating a limb that is moving at high velocity (17), such as during a punch or a kick. Additionally, shoulder muscle-tendon strains have been reported as common injuries in National Collegiate Athletic Association men's wrestlers (1), whereas groundwork combat from certain bottom positions such as the guard may put MMA athletes at increased risk of groin strains. As such, it is likely that shoulder, hamstring, and groin strains are common preventable injuries within this population. Joint sprains are reported to be the second leading form of preventable injuries to MMA athletes, representing 17.3% of the total competition and training injuries (41). Although the location of these injuries was not described, Agel et al. (1) report that ankle and knee ligament injuries predominate in college wrestlers. Thus, it is reasonable to conclude that this may also hold true to some extent for MMA athletes.

In addition to these preventable MMA injuries, other considerations should be included in a thorough injury prevention plan for this sport. Although largely nonpreventable from a strength and conditioning standpoint, it is important to consider that the risk of concussions in MMA is inherently high in both training and competition. It has been reported that concussions represent 20% of all competition-related injuries (44). Epidemiological data for MMA indicate that the majority of competition and pooled competition and training injuries occur to the head (35), suggesting increased opportunity for concussions. With this in mind, coaches working with these athletes should be educated on the signs, symptoms, and return to play protocols associated with such an injury (27). Finally, a lack of physical fitness has been related to increased injury risk among contact sport athletes (16,31). Clearly, such a risk factor is directly influenced by the strength and conditioning coach and therefore should be addressed in an injury prevention plan for mixed martial artists. Taken together, injury reduction strategies for the MMA athlete should consider muscle-tendon strains to the hamstring, groin, and shoulder, and ligament injuries to the ankle and knee, in addition to the management of concussions and the enhancement of physical fitness.

Back to Top | Article Outline

INJURY PREVENTION PLAN DESIGN

For an injury reduction plan to be effective, it should target interventions toward athletes who are at increased risk for each injury (4,25). Furthermore, it is important to recognize that athletes may show low compliance to such training plans (39). Thus, these interventions will need to be delivered in such a way that participation is increased. In consideration of these factors, the following strategy will identify at-risk athletes to be targeted for each intervention, in addition to suggesting methods for integrating these activities into a training plan to minimize extended training time, thereby increasing compliance. With this in mind, inclusion of these tasks can occur by the warm-up, in the recovery period between sets or as modifications of traditional resistance training exercises.

Back to Top | Article Outline

INJURY PREVENTION PLAN

HAMSTRING STRAIN

Many kicking techniques require combined hip flexion and knee extension causing a rapid eccentric action of the hamstrings as they decelerate the tibia. Sports that involve frequent applications of this mechanism, such as sprinting or change of direction maneuvers, report high rates of hamstring injuries (2,49). During the late swing phase of a stride action, similar to that of a kicking action, hamstrings provide their highest electromyographic readings, and this increases with running speed (28). Accordingly, this phase of the movement corresponds to high rates of hamstring injures (32).

Using a hypothetical biomechanical model, Thelen et al. (47) reported considerable stretching of the biceps femoris tendon during sprinting, whereas the fascicle length remained relatively constant, thereby minimizing the eccentric activity. This suggests that poor compliance of the tendon, such as is seen from scar tissue after an injury, increases the eccentric load on the muscle fibers, thereby increasing the potential to reinjury to the region.

Finally, it has been suggested that injured hamstrings produce their greatest force earlier in the length-tension relationship than uninjured hamstrings, resulting in an extended descending limb phase (the period after peak tension), where the peak torque occurs at shorter hamstring lengths (Figure 1) (32). This descending limb period of the length-tension relationship is considered an area of vulnerability for hamstrings (11). For example, such an injury would impact a push kick (keep) in 2 ways: (a) a greater opportunity for injury because of the shift in peak tension causing an increased portion of the action occurring under decreasing tension yet increasing length and (b) with peak force now occurring earlier in the strike, this limits its effectiveness as a tool to keep distance from the opponent.

Figure 1

Figure 1

In consideration of the increased vulnerability during the descending limb phase, the primary objective of a hamstring injury prevention program is to shift the length-tension relationship to the right (Table 1). This will allow peak tension to occur at a longer length, which reduces the impact of this portion of the curve. For this reason, simply stretching or strengthening alone is not the most effective strategy. Rather, eccentric exercise is proposed as an effective method for shifting peak hamstring torque to a longer muscle length (8). Specifically, Nordic hamstring curls (Figure 2) result in a long-lasting shift in the length-tension relationship (7) and elicit the highest degree of hamstring activation when compared with alternative lower-body resistance training activities (14). These exercises have been used successfully in injury prevention programs resulting in considerable reductions in hamstring injuries (3,9). It seems as though Nordic curls should be delivered in a fatigued state, as this increases eccentric hamstring to concentric quadriceps ratio and maintains this ratio to a greater extent after a sports-specific training session, when compared with the same activities delivered in an unfatigued state (46). This is an important consideration, as hamstring injuries commonly occur when fatigued (50,51).

Table 1

Table 1

Figure 2

Figure 2

Back to Top | Article Outline

GROIN INJURIES

Similar to hamstrings, the groin musculature is placed under considerable stress during many kicking and ground fighting techniques. There are a number of performance implications of a groin injury such as a loss of mobility, diminished power, and discomfort during kicking techniques (36). As adductor strains are the most common cause of acute groin injuries in athletes, increasing hip adductor strength and musculotendinous flexibility should form a central role in the prevention of these injuries (34). Additionally, effective management of training load should also be implemented to protect against tendinopathies in this area (12).

Multidirectional lunging patterns can be included in dynamic warm-up for all athletes (Table 2). This will improve the mobility of the region. Additionally, the side-lying hip raise (Figure 3) can be incorporated toward the end of the dynamic warm-up. As an assistance exercise during the body of the workout, a loaded lateral barbell lunge will aid in developing both strength and mobility of the groin. For chronic groin pain underpinned by tendinopathy, monitoring of the volume of kicks and time spent in the guard position when grappling should be conducted. A sport-specific session with an increased volume of these techniques should be followed by periods of restitution to allow recovery and adaptation. Type I collagen synthesis, indicating the process of tendon repair, has been reported after 96 hours following mechanical stimulus (20). Thus, 4-day cycles of high groin-related training load should be programmed (25). High groin-load days might include extensive guard work and kicking actions, whereas low groin-load days can include boxing and clinching tasks, and grappling from the top position, particularly cross-side.

Table 2

Table 2

Figure 3

Figure 3

Back to Top | Article Outline

SHOULDER INJURY

The high-velocity action underpinning an effective punch requires a great degree of dynamic stabilization of the glenohumeral joint. Additionally, the shoulder joint is aggressively manipulated during grappling exchanges. This puts the region at considerable risk of injury among MMA athletes. In athletes who require these exceptional stabilization qualities of the glenohumeral joint, exercises to strengthen and improve motor control of the rotator cuff have been suggested (30,45). In particular, combined shoulder abduction and external rotation movements would be ideal to replicate the deceleration demands of a punch (Figure 4). Table 3 outlines the prevention plan for these injuries.

Figure 4

Figure 4

Table 3

Table 3

Back to Top | Article Outline

ANKLE INJURY

Stand-up battles involve frequent ballistic actions expressed by the lower limb in response to external stimuli. This includes the execution of kicks, short and rapid lateral movements, and powerful changes in levels. When stand-up grappling, quick shifts of the MMA fighter's center-of-mass (COM) challenges the balance while the ankle is put in precarious positions during ground fighting from both the top and bottom positions. This highlights the considerable potential for injury to the ankle. Athletes who have sustained a previous ankle injury are 80% more likely to experience that injury again in the future (52). Thus, these athletes should be targeted for interventions. Poor neuromuscular control (10,42,43) and joint force sense (13) are reported among athletes with a history of ankle injury. As such, activities that improve both stability and the ability to manage ground reaction forces should be included for these athletes. Furthermore, a reduced firing frequency of the peroneus longus (33) has been described among this population, suggesting that preactivation of this musculature could prove beneficial (25). Additionally, only weak relationships exist between ankle strength and stability (6,29), indicating that improved motor control about the ankle should be prioritized over increased strength (25). Table 4 outlines the prevention plan for these injuries.

Table 4

Table 4

Back to Top | Article Outline

KNEE INJURY

An exceptional base-of-support and proximal control of the COM underpins most MMA actions. This stable foundation is contributed to by precise alignment of the ankle, knee, and hip, whereas deviation from this can result in excess torque about the knee joint increasing the risk of injury to this region. Specifically, deceleration actions whereby knee valgus occurs during low angles of knee flexion, combined with excessive internal or external rotation, put athletes at greater risk of noncontact anterior cruciate ligament injuries (ACL) (40). Similar to ankles injuries, techniques whereby the athlete performs rapid changes of direction such as the entry to a takedown, rearward, or lateral movement to evade attacks, or the redistribution of the COM over a single-leg base-of-support, such as kicking techniques, put the athlete at increased risk of knee ligament injury. For athletes with poor lower-limb alignment, this will need to be rectified through increasingly more challenging deceleration and ballistic activities (19). The reader is directed to Herrington and Comfort (22) for a detailed description of these tasks. Training programs incorporating these tasks have resulted in reductions to knee ligament injuries (19,54). Additionally, hamstring strengthening minimizes anterior tibial shearing and is recommended as a prevention strategy for ACL injuries (5,15).

The strength and conditioning coach should apply attentive qualitative analysis to identify these pathomechanics (37). Any fighters displaying such movement deficiencies should be targeted for neuromuscular and motor control tasks (Table 5). These hazardous movement strategies may be more common in developing athletes where movement proficiency has yet to be mastered, or in female athletes where noncontact ACL injuries are typically more common (53). Submaximal ballistic actions such as depth drop variations, lateral movement drills, and reactionary tasks can be prescribed to improve neuromuscular capacity (18,19). Implicit coaching techniques should promote “quiet” ground contacts and “efficient” transition through eccentric, amortization, and concentric phases of stretch-shortening cycle activities (25). This will occur in conjunction with lower-limb joint congruency and greater angles of flexion at the knee and hip during vertical landing tasks (18,21). Additionally, an increased volume of hamstring strengthening exercises can be included during the body of the workout.

Table 5

Table 5

Back to Top | Article Outline

OTHER INJURY CONSIDERATIONS

CONCUSSIONS

The full contact nature of MMA puts athletes at an increased risk of concussions, which is a factor that must be considered by all coaches. Although headgear and mouthpieces are essential equipment for the mixed martial artist, coaches and athletes should also be educated on the symptoms of this injury (Table 6), so appropriate medical interventions can be undertaken (27). In many cases, the symptoms of concussion resolve in 7–10 days. When the athlete is completely asymptomatic at rest, they may begin light exercise. More complex sport-specific tasks can then follow. Noncontact training with a greater degree of decision making and reaction should follow before resumption of higher intensity drills. If any signs or symptoms appear, the athlete should return to the previous stage of this process. Only after medical clearance should the athlete return to full contact sparring. If symptoms return, the athlete should immediately cease such activities, and once symptoms resolve the athlete should again seek medical clearance before returning to full training (38).

Table 6

Table 6

Back to Top | Article Outline

FITNESS FATIGUE

Fatigue has been correlated with increased injury rates among athletes in subelite collision sports with similar bioenergetic demands to MMA (16). Because of the high training workloads undertaken by the mixed martial artist, they are particularly susceptible. Effective implementation of periodization, monitoring, and tapering strategies will assist in minimizing fatigue-induced injuries (48). The reader is directed to “Periodization for mixed martial arts” by James et al. (24) for further information on training plan design.

Back to Top | Article Outline

CONCLUSIONS

Methods for minimizing injuries are important to the success of any athlete. This need is even more apparent in MMA, where heavy physical contact and high training volumes are commonplace. This article has identified the most common injuries in this sport and proposed training strategies for their reduction. Athletes at increased risk should be targeted, while integrating these tasks into a training plan in a way that minimizes the impact on training time will improve compliance. However, further research is needed to more accurately identify the most common preventable injuries in this sport in addition to the effectiveness of the proposed training interventions on their reduction.

Back to Top | Article Outline

REFERENCES

1. Agel J, Ransone J, Dick R, Oppliger R, Marshall SW. Descriptive epidemiology of collegiate men's wrestling injuries: National Collegiate Athletic Association Injury Surveillance System, 1988–1989 through 2003–2004. J Athl Train 42: 303–310, 2007.
2. Agre JC. Hamstring injuries. Sports Med 2: 21–33, 1985.
3. Arnason A, Andersen T, Holme I, Engebretsen L, Bahr R. Prevention of hamstring strains in elite soccer: An intervention study. Scand J Med Sci Sports 18: 40–48, 2008.
4. Bahr R, Krosshaug T. Understanding injury mechanisms: A key component of preventing injuries in sport. Br J Sports Med 39: 324–329, 2005.
5. Beynnon BD, Fleming BC, Johnson RJ, Nichols CE, Renström PA, Pope MH. Anterior cruciate ligament strain behavior during rehabilitation exercises in vivo. Am J Sports Med 23: 24–34, 1995.
6. Beynnon BD, Renström PA, Alosa DM, Baumhauer JF, Vacek PM. Ankle ligament injury risk factors: A prospective study of college athletes. J Orthop Res 19: 213–220, 2001.
7. Brockett CL, Morgan DL, Proske U. Human hamstring muscles adapt to eccentric exercise by changing optimum length. Med Sci Sports Exerc 33: 783–790, 2001.
8. Brockett CL, Morgan DL, Proske U. Predicting hamstring strain injury in elite athletes. Med Sci Sports Exerc 36: 379–387, 2004.
9. Brooks JH, Fuller CW, Kemp SP, Reddin DB. Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union. Am J Sports Med 34: 1297–1306, 2006.
10. Brown CN, Mynark R. Balance deficits in recreational athletes with chronic ankle instability. J Athl Train 42: 367–373, 2007.
11. Brughelli M, Cronin J. Preventing hamstring injuries in sport. Strength Cond J 30: 55–64, 2008.
12. Cook J, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. Br J Sports Med 43: 409–416, 2009.
13. Docherty CL, Arnold BL. Force sense deficits in functionally unstable ankles. J Orthop Res 26: 1489–1493, 2008.
14. Ebben W. Hamstring activation during lower body resistance training exercises. Int J Sports Physiol Perform 4: 84, 2009.
15. Fleming BC, Renstrom PA, Ohlen G, Johnson RJ, Peura GD, Beynnon BD, Badger GJ. The gastrocnemius muscle is an antagonist of the anterior cruciate ligament. J Orthop Res 19: 1178–1184, 2001.
16. Gabbett TJ, Domrow N. Relationships between training load, injury, and fitness in sub-elite collision sport athletes. J Sports Sci 25: 1507–1519, 2007.
17. Garrett W Jr. Muscle strain injuries. Am J Sports Med 24: S2–S8, 1995.
18. Garrett W Jr, Yu B. Congruence between existing prevention programs and research on risk factors and mechanisms of noncontact ACL injury. Presented at Hunt Valley II Meeting, 2005.
19. Griffin LY, Albohm MJ, Arendt EA, Bahr R, Beynnon BD, DeMaio M, Dick RW, Engebretsen L, Garrett WE, Hannafin JA. Understanding and preventing noncontact anterior cruciate ligament injuries. A review of the Hunt Valley II Meeting, January 2005. Am J Sports Med 34: 1512–1532, 2006.
20. Heinemeier K, Langberg H, Olesen JL, Kjaer M. Role of TGF-β1 in relation to exercise-induced type I collagen synthesis in human tendinous tissue. J Appl Physiol (1985) 95: 2390–2397, 2003.
21. Henderson J, Hunter S, Berry W. The biomechanics of the knee during the parachute landing fall. Mil Med 158: 810–816, 1993.
22. Herrington LC, Comfort P. Training for prevention of ACL injury: Incorporation of progressive landing skill challenges into a program. Strength Cond J 35: 59–65, 2013.
23. James L, Beckman EM, Kelly VG. The impact of prehabilitation training on the development of strength and power in a block periodised training plan. J Aust Strength Cond 22: 5–16, 2014.
24. James L, Kelly V, Beckman E. Periodization for mixed martial arts. Strength Cond J 35: 35–45, 2013.
25. James L, Kelly V, Beckman E. An injury risk management plan for volleyball. Sports Med, 2014. May 23. [Epub ahead of print].
26. Järvinen TA, Järvinen TL, Kääriäinen M, Kalimo H, Järvinen M. Muscle injuries biology and treatment. Am J Sports Med 33: 745–764, 2005.
27. Johnson EW, Kegel NE, Collins MW. Neuropsychological Assessment of sport-related concussion. Clin Sports Med 30: 73–88, 2011.
28. Jönhagen S, Ericson MO, Nemeth G, Eriksson E. Amplitude and timing of electromyographic activity during sprinting. Scand J Med Sci Sports 6: 15–21, 1996.
29. Kaminski TW, Hartsell HD. Factors contributing to chronic ankle instability: A strength perspective. J Athl Train 37: 394–405, 2002.
30. Kugler A, Krüger-Franke M, Reininger S, Trouillier H, Rosemeyer B. Muscular imbalance and shoulder pain in volleyball attackers. Br J Sports Med 30: 256–259, 1996.
31. Lauersen JB, Bertelsen DM, Andersen LB. The effectiveness of exercise interventions to prevent sports injuries: A systematic review and meta-analysis of randomised controlled trials. Br J Sports Med 48: 871–877, 2014.
32. Lee M, Reid SL, Elliott BC, Lloyd DG. Running biomechanics and lower limb strength associated with prior hamstring injury. Med Sci Sports Exerc 41: 1942–1951, 2009.
33. Leumann A, Ebneter L, Von Tscharner V, Valderrabano V. Neuromuscular patterns in chronic ankle instability. Br J Sports Med 45: 323–324, 2011.
34. Lovell G. The diagnosis of chronic groin pain in athletes: A review of 189 cases. Aust J Sci Med Sport 27: 76–79, 1995.
35. Lystad RP, Gregory K, Wilson J. The epidemiology of injuries in mixed martial arts a systematic review and meta-analysis. Orthop J Sports Med 2: 1–10, 2014.
36. Maffey L, Emery C. What are the risk factors for groin strain injury in sport? Sports Med 37: 881–894, 2007.
37. Magill R. Motor Learning and Control-Concept and Applications. Boston, MA: McGraw-Hill Higher Education, 2011.
38. McCrory P, Meeuwisse W, Johnston K, Dvorak J, Aubry M, Molloy M, Cantu R. Consensus statement on Concussion in Sport—The 3rd International Conference on Concussion in Sport held in Zurich, November 2008. South Afr J Sports Med 21: i76–i84, 2009.
39. Myklebust G, Engebretsen L, Braekken I, Skjolberg A, Olsen O, Bahr R. Prevention of anterior cruciate ligament injuries in female team handball players: A prospective intervention study over three seasons. Clin J Sport Med 13: 71–78, 2003.
40. Quatman CE, Hewett TE. The anterior cruciate ligament injury controversy: Is “valgus collapse” a sex-specific mechanism? Br J Sports Med 43: 328–335, 2009.
41. Rainey LCE. Determining the prevalence and assessing the severity of injuries in mixed martial arts athletes. N Am J Sports Phys Ther 4: 190, 2009.
42. Ross SE, Guskiewicz KM. Examination of static and dynamic postural stability in individuals with functionally stable and unstable ankles. Clin J Sport Med 14: 332–338, 2004.
43. Ross SE, Guskiewicz KM, Yu B. Single-leg jump-landing stabilization times in subjects with functionally unstable ankles. J Athl Train 40: 298–304, 2005.
44. Scoggin JF III, Brusovanik G, Pi M, Izuka B, Pang P, Tokumura S, Scuderi G. Assessment of injuries sustained in mixed martial arts competition. Am J Orthop (Belle Mead NJ) 39: 247–251, 2010.
45. Seminati E, Minetti AE. Overuse in volleyball training/practice: A review on shoulder and spine-related injuries. Eur J Sport Sci 13: 732–743, 2013.
46. Small K, McNaughton L, Greig M, Lovell R. Effect of timing of eccentric hamstring strengthening exercises during soccer training: Implications for muscle fatigability. J Strength Cond Res 23: 1077–1083, 2009.
47. Thelen DG, Chumanov ES, Hoerth DM, Best TM, Swanson SC, Li L, Young M, Heiderscheit BC. Hamstring muscle kinematics during treadmill sprinting. Med Sci Sports Exerc 37: 108–114, 2005.
48. Vetter RE, Symonds ML. Correlations between injury, training intensity, and physical and mental exhaustion among college athletes. J Strength Cond Res 24: 587–596, 2010.
49. Warren P, Gabbe BJ, Schneider-Kolsky M, Bennell KL. Clinical predictors of time to return to competition and of recurrence following hamstring strain in elite Australian footballers. Br J Sports Med 44: 415–419, 2010.
50. Woods C, Hawkins R, Maltby S, Hulse M, Thomas A, Hodson A. The Football Association medical research Programme: An audit of injuries in professional football—Analysis of hamstring injuries. Br J Sports Med 38: 36–41, 2004.
51. Worrell TW. Factors associated with hamstring injuries. Sports Med 17: 338–345, 1994.
52. Yeung M, Chan K-M, So C, Yuan W. An epidemiological survey on ankle sprain. Br J Sports Med 28: 112–116, 1994.
53. Yu B, Garrett WE. Mechanisms of non-contact ACL injuries. Br J Sports Med 41: i47–i51, 2007.
54. Zebis MK, Bencke J, Andersen LL, Døssing S, Alkjær T, Magnusson SP, Kjaer M, Aagaard P. The effects of neuromuscular training on knee joint motor control during sidecutting in female elite soccer and handball players. Clin J Sport Med 18: 329–337, 2008.
Keywords:

combat sports; mixed martial arts; injury prevention

© 2014 by the National Strength & Conditioning Association