Dear Editor,

I read with interest the article written by Dr. G.J. Buse entitled, No holds barred sport fighting: a 10 year review of mixed martial arts competition published in the 6 February 2006 edition of your journal. As a researcher focused on injury prevention, I have recently been part of a research group reviewing data from both mixed martial arts competitions and professional boxing and enjoyed reading the information presented by Dr. Buse.

In an article published in October 2005 in the Southern Medical Journal, our research group attempted to define the overall injury rate of athletes participating in professional boxing.[1] We reviewed data from the fight cards published by the Nevada State Athletic Commission and noted any injury comments recorded by the ringside physicians. Our research demonstrated an overall injury rate of 17.[1] injuries per 100 boxer-matches with 11.3% of those matches ending in knockout.

In an attempt to compare boxing injuries to mixed martial arts (MMA) injuries, we did a review of the fight cards for MMA matches using the same protocol as for the professional boxing matches. Our data—to be published soon by The Journal of Sports Science and Medicine—indicate that the overall injury rate for MMA matches is similar to professional boxing and the knockout rate is almost half that of professional boxing.[2]

In reviewing Dr. Buse’s data, I would have liked to have seen a comparison of injury rates before and after the sanctioning of the sport in September 2001. Though MMA began in the United States in 1993, these first fights only superficially resemble MMA matches today and were really very different competitions. Sanctioning brought about many rule changes that mandated weight classes, time limits for rounds and matches, and eliminated many of the most dangerous techniques including stomps, head butts, and groin attacks. Combining MMA matches prior to sanctioning with the sanctioned matches of today is confusing and is not helpful in attempting to determine the true injury risk for participants in these competitions.

It should also be noted that although there were five deaths in the boxing ring in the United States during 2005, there has never been an MMA death in the United States. The death cited by Dr. Buse occurred in an unregulated event during 1998 in the Ukraine.[3] MMA fighters in the United States now must pass all the prefight screening tests of professional boxers and are supervised by referees and ringside physicians. It is important not to lump MMA competitions with the infamous “Toughman” competitions—a “sport” that matches amateur participants against trained fighters using “one size fits all” protective gear and often supervised by chiropractors and other untrained medical staff—when comparing MMA to other combat sports. While MMA has never had a casualty in the United States, at least 12 deaths have resulted from Toughman competitions.[4]

MMA also has some rules that seem to be an improvement over professional boxing. The fact that MMA has no “standing eight count” enabling a concussed participant time to recover and continue fighting is a tremendous step toward diminishing traumatic brain injury. Furthermore, by allowing leg and arm attacks opponents have a more diverse target area and do not focus solely on attacking the head, and if in trouble, a participant can “tap out” to signify his desire to end the match. In our study, the “tap out” was the second most common means of ending a bout and ended approximately 30% of matches.2 Last, most MMA matches are far shorter than boxing matches. Sanctioned MMA events usually consist of three 5 minute rounds as compared to the usual ten to twelve rounds of boxing.

In sum, mixed martial arts competitions are a controversial subject in today’s sporting world and while no one would argue that these events are safe, it is important that we in the medical and research communities stay disciplined in our response to these subjects. I am thankful that your journal has taken an active role in seeking to determine the inherent risks of MMA competitions, and I hope that it will continue giving balanced and constructive suggestions regarding MMA and other such controversial subjects.

Sincerely,

Gregory H. Bledsoe MD, MPH
Assistant Professor
Department of Emergency Medicine
The Johns Hopkins University School of Medicine Baltimore, Maryland

References

1. Bledsoe GH, Li G, Levy, F. Injury risk in professional boxing. Southern Med J 2005; 98:994-998.

2. Bledsoe GH, Hsu EB, Grabowski JG, Brill JD, Li G. Incidence of injury in professional mixed martial arts competitions. The Journal of Sports Science and Medicine (in press).

3. Porter K. Chipley man dies from injuries suffered in “ultimate fighting” match [news article online]. Panama City, FL: The News Herald, 1998, http://ap.emeraldcoast.com/nharchive/index.php (accessed 6 Feb 2006).

4. Branch, G. Toughman Competition Faces Its Own Battle. USA Today, 3C, 20 May 2003.

Dear Editor,

The influence of a regular physical exercise on health and fitness is well-established, as physically active subjects are characterized by a consistently decreased risk of cardiovascular disease, diabetes, cancer, osteoporosis, obesity, fractures and mental health problems. Accordingly, the current guidelines recommend 30 minutes or more of moderate-intensity activity on most days of the week, and that people already achieving this would benefit further from participation in more vigorous activity.[1]

However, there is still an open debate regarding the intensity and the type of physical activity required to achieve most favourable health changes in the general population without overwhelming the relative benefits or eliciting osteoarthritis and cardiovascular abnormalities not present at rest.[2] It was recently observed that the volume of lifestyle activities of moderate intensity in leisure time was inversely associated with all cause mortality in women but not in men and. Therefore, with regard to the health enhancing physical activity recommendation as a threshold, there were favourable findings only in women.[3]

In recent investigations on male professional athletes, we demonstrated that a vigorous and regular endurance aerobic training regimen does not influence markers of hemostatic or endothelial activation,[4] does not induce any persistent phlogistic reaction,[5] nor it is associated with biochemical signs of significant and irreversible chronic cardiac involvement, as reflected by normal concentrations of the NT-pro-brain natriuretic peptide.[6]

Therefore, as a substantial intensification in leisure-time physical activity within the population does not apparently produces any acute increase of the risk of adverse cardiovascular events[4-6] and it is likely to be more effective for eliciting supplemental gains in health,[2] we suggest that higher intensities and amounts of aerobic training may be safely implemented in free-living sedentary individuals as a preventive or therapeutic measure to increase the health benefits, especially in individuals who are most at risk of developing health problems.

References

1. Willett W. Harvesting the fruits of research: new guidelines on nutrition and physical activity. Cancer J Clin 2002; 52: 66-67.

2. Lee, IM, Sesso, HD, Oguma, Y, Paffenbarger, RS Jr Relative intensity of physical activity and risk of coronary heart disease. Circulation 2003; 107: 1110-1116.

3. Bucksch J. Physical activity of moderate intensity in leisure time and the risk of all cause mortality. Br J Sports Med 2005;39:632-8.

4. Lippi, G, Salvagno, GL, Montagna, M, Guidi, GC Chronic influence of vigorous aerobic training on hemostasis. Blood Coagul Fibrinolysis 2005; 16: 533-534.

5. Lippi, G, Salvagno, GL, Guidi, GC Other advantages to aerobic exercise. CMAJ 2005;173:1066.

6. Lippi, G, Salvagno, GL, Montagnana, M, Schena, F, Balestrieri, F, Guidi, GC Influence of physical exercise and relationship with biochemical variables of NT-pro-brain natriuretic peptide and ischemia modified albumin. Clin Chim Acta (in press).

Dear Editor

It was a pleasure to read Paul McRory championing the cause of comparative animal and human physiology, and of his equine example.(1) To the latter he might have added that, because the horse is entirely a nasal breather, attempts were made, from 1800 BC in Egypt to 17th century Europe, to increase its ventilation by slitting the nostrils, paralleling the (equally futile) attempts of modern runners with nasal strip dilators.

More seriously, alongside its ventilatory-locomotor coupling due to the threefold effects of the visceral piston, the cervical pendulum and scapular-thoracic-compression which he mentioned, is the fact that the horse effectively blood dopes during its race warm-up. Autonomic splenic contraction releases enough erythrocytes to increase the haematocrit from a resting mean of around 40% to an extraordinary racing level of 60% or higher. The horse also undergoes a longer term training hypervolaemia comparable to human endurance athletes. All this gives it a VO2max of the order of 180? 200ml.kg.min, and a mile time of 1min 35s, so perhaps the horse is not particularly 'physiologically limited'? Mind you, this hardly compares with the VO2max of ~300ml.kg.min, and 58mph top speed, of the North American Pronghorn Antelope. However, the horse's particular pulmonary hypertension and highly elevated left atrial pressure are believed to cause stress failure of pulmonary capillaries, giving the syndrome of equine exercise-induced pulmonary haemorrhage,(2) although the exact pathogenesis has not been elucidated. Finally, regarding the horse and its rider, in some equine events, the rider may be nearer the human maxima for heart rate and blood lactate than the horse is to its maxima, i.e. the rider may be working harder than the horse.

Competing interests

None declared

References

1 McCrory P. Horses for courses. Br J Sports Med 2005; 39:581.

2 West JB, Matthieu-Costello O. Stress failure of pulmonary capillaries as a mechanism for exercise-induced pulmonary hypertension in the horse. Equine Vet J 1994; 26: 441-7.

Dear Editor,

While Orchard and colleagues[1,2] should be congratulated for their attempt at developing an international consensus on the definition of a cricket-related injury, a broader look at the literature on definitions of injury might have provided a more robust definition of a cricket injury.

Orchard et al.[1, 2] define a cricket injury (or significant injury) as “any injury or other medical condition that either (a) prevents a player from being fully available for selection for a major match or (b) during a major match, causes a player to be unable to bat, bowl, or keep wicket when required by either the rules or the team’s captain.” While the definition proposed seems easy to implement in practice, it does not actually define what would be considered to be a cricket-related injury in terms of physical tissue damage, which is the basis of generally accepted definitions of injury, nor does it define what is a medical condition.

The confusion may stem from the theoretical versus the operational definitions of an injury. For example, one of the most common theoretical injury definitions defines an injury as being “...caused by acute exposure to physical agents such as mechanical energy, heat, electricity, chemicals, and ionizing radiation interacting with the body in amounts or at rates that exceed the threshold of human tolerance. In some cases (for example, drowning and frostbite), injuries result from the sudden lack of essential agents such as oxygen or heat”.[3] However, to operationalise this definition of an injury, many injury professionals rely on the International Classification of Disease, 10th revision (ICD-10) injury and poisoning chapter XIX (S00-T98)[4] or the earlier ICD-9 external cause codes (800-999)[5] to define what constitutes an injury.

What is lacking for the Orchard et al injury definition for cricketers is how an injury would be specifically defined theoretically (i.e. in terms of physical tissue damage), and then how such a definition would be operationalised (i.e. how will physical tissue damage be consistently identified and recorded). Although latent effects of physical tissue damage, such as musculoskeletal injuries, are excluded from the general theoretical injury definition above, as these conditions do not immediately exceed the threshold of human tissue tolerance (but rather often result from low energy exposures that can accumulate over time until tolerance is exceeded)[6], it is likely that Orchard et al would wish to include these injuries in an operational definition of a cricket-related injury as musculoskeletal injuries represent a large proportion of reported cricket-related injuries.[7,8] In addition, using Orchard et al’s injury definition, other medical conditions (for example, an illness such as influenza) would also be included, even those these are not injuries. Indeed, it is unclear whether something like stress would be included under their definition. Finally, it is also unclear whether an injury sustained outside the sporting arena, for example from a motor vehicle crash, that prevented the player from being ‘fully available for selection’ would be included in the Orchard et al definition of injury.

Poorly defined operational definitions of injury are not new to the sports area.[9] We would encourage Orchard and colleagues to consider the development and publication of a more specific theoretical definition together with an operational definition of cricket-related injury in order to ensure standardisation of a case definition and to contribute towards obtaining high sensitivity and specificity for identification of injuries to cricketers. Otherwise the incidence of cricket-related injury is sure to vary due to different interpretations of what is an injury, making international comparisons difficult.

Furthermore, the currently proposed cricket injury definition appears to be intended for elite cricketers and whether or not this definition could be consistently applied to other levels of the competition (eg. community level) would be of interest.

References

1. Orchard, J., Newman, D., Stretch, R., Frost, W., Mansingh, A., and Leipus, A., Methods for injury surveillance in international cricket. British Journal of Sports Medicine, 2005. 39(4): p. e22-e29.

2. Orchard, J., Newman, D., Stretch, R., Frost, W., Mansingh, A., and Leipus, A., Methods for injury surveillance in international cricket. Journal of Science & Medicine in Sport, 2005. 8(1): p. 1-14.

3. Baker, S., O'Neil, B., Ginsburg, M., and Guohua, L., The Injury Fact Book. 1992, New York: Oxford University Press.

4. World Health Organisation, ICD-10 International Classification of Diseases, 10th revision. 1992, Geneva: WHO.

5. World Health Organisation, ICD-9 International Classification of Diseases, 9th revision. 1977, Geneva: WHO.

6. Kumar, S., Theories of musculoskeletal injury causation. Ergonomics, 2001. 44(1): p. 17-47.

7. Leary, T. and White, J., Acute injury incidence in professional country club cricket players (1985-1995). British Journal of Sports Medicine, 2000. 34: p. 145-147.

8. Orchard, J., James, T., Alcott, E., Carter, S., and Farhart, P., Injuries in Australian cricket at first class level 1995/1996 to 2000/2001. British Journal of Sports Medicine, 2002(270-275).

9. Finch, C.F., An overview of some definitional issues for sports injury surveillance. Sports Medicine, 1997. 24(3): p. 157-63.