University of Vermont AAHS

 

AMEA

March 2001, Vol. XII, Number 1

 Table of Contents

 

Helmet Safety Test
The Game of Polo
from the AMEA President
Safety Alert
Pardon Us
Fact Sheet: Horses and Children
from the AMEA Library
An Experimental model of sudden death
Medical Implications: Masters of Foxhounds Survey


Return to AMEA Page


 

1998 United States Polo Association Safety Committee

Helmet Safety Test

Performed by Wayne State Bioengineering Lab

Tim Nice, M.D., Chairman, Safety Committee

In the spring of 1997, the Executive Committee of the U.S. Polo Association sanctioned the Polo Safety Committee to collect polo helmets from retailer’s shelves and test those helmets according to our established safety index. In that some junior players still use the conventional hunt cap, we also tested the most widely sold hunt cap as well as a popular Bell motorcycle helmet. The Executive Committee has started a precedent in that periodically helmets will be taken off retailer’s shelves and sent for independent testing by the Safety Committee. It has also been resolved that if a manufacturer introduces a new helmet into the marketplace, that agent should send his helmet to the Wayne State Testing Laboratory before the helmet is introduced into the retail market. The cost of such testing would be incurred by the manufacturer of that helmet. At a later date, the Safety Committee would arbitrarily collect the same helmet from a retail store and in their own independent safety test that would be performed by the Wayne State Bioengineering Laboratory. The last such thorough testing of polo helmets occurred in 1987. It was during the 1980s while working with the Wayne State Bioengineering Laboratory, that the severity index standards for polo helmets was developed. It so happens that the current NOCSAE (National Organizational Committee for Safety Athletic Equipment) standards for polo helmets are the most stringent standards for any sports helmet.

In addition to the safety test, the Safety Committee felt that it was important to know some practical questions about these helmets. For instance, if the helmet has a shelf life of over five years, should it be discarded and not worn by a player? What effect does drilling holes and attaching a facemask has to the structural integrity of the helmet? What force does it take, for instance, if a horse were to roll across the helmet to crush the helmet? In the 1980s and the early 1990s, the Safety Committee did three player injury survey studies. Those studies have been published in Polo Magazine over the past few years. There were some striking results from those studies. Despite the fact that fractures, bruises and contusions constitute 54% of the injuries mostly to the arm, face, head and neck areas, concussions at 11% remains a daunting figure. 33% of the body injuries occurred to the facial area, thus compelling us to look at the facemask, goggle issue. In 1993, 70% of the nine different helmets used in interscholastic polo did not even meet our safety standards. It is out of such studies that the Safety Committee has repeatedly recommended to all players, but especially junior players and their parents that approved safety helmets with a facemask are selected. Those test results have regularly been published in Polo Magazine and are available in respected retail stores.

Helmets will not protect against all head injuries, albeit falling off a horse, motorcycle or playing ice hockey. We recommend that the safest construct is to place a competent facemask on all helmets. Helmets with and without facemasks will not protect against neck injury. There have been arguments that a facemask could conceivably cause a neck injury, but that has not been the experience of the Safety Committee. We do not know of any neck injury causally related to wearing a helmet with or without a facemask. Current testing of helmets show that the helmet will crush and deform with a force of 500-800 pounds applied to the side of the helmet; that is if a horse were to roll across one’s head.

Over the past 10 years, we have seen the disappearance of some helmets while others have become more popular (mostly for cosmetic reasons). We have seen an insurgence of helmets from South America that for the most part, has no testing standards applied to them at all. Some helmets have disappeared because of such a low demand for polo helmets that it is not practical to continue manufacturing them. Nevertheless, over the past year, we were surprised to find 14 helmets in current use. The important number to remember when looking at the helmet selection data is 1100. If the number is below 1100, it becomes a safer helmet and the risk of severe brain injury decreases dramatically. However, if the number of the test goes above 1100, then the risk of severe brain injury graphically increases as well. The helmets are tested from four sides - the front, the side, the rear and the top, and therefore receive four different scores. The helmets may score differently from different positions and, of course, the ideal scenario would be to have all four scores under 1100. More often than not, that is not the case, but if the helmet scores well in at least three of those categories, the fourth one should probably not be far out of line. Of the 14 helmets tested, the Bond Street, the Polo Gear 2000 and the Spectra helmets had the best results. If we were to do a cumulative score rating, there were very few mid-range helmets and some very obvious poorly constructed helmets. I think it is important to note that the hunt cap does not test well and probably should not be used as a polo helmet and, interestingly, the Bell Hard Shell motorcycle helmet tested only slightly better than the hunt cap. All helmets received two tests. Only two helmets clearly stood out as having a good recovery rate and that was the Bond Street 1998 and the Polo Gear 2000. The remainder of the helmets when tested the second time show that there was a dramatic increase in the severity index to above 1100. This data should be interpreted that these helmets should be discarded were one to have a severe head injury and, especially if there was an obvious crack in the helmet after a traumatic incident. All helmets were tested with a conventional commercial chinstrap. Breaking of the chinstrap was not a factor and, with chin straps that have a plastic buckle and those have been known to break. There is also an occasional chin strap with a steel buckle and aside form the rusting of the steel buckle, there was no reason to believe that there was any safety issue with a conventional under the chin strap or the buckle type straps.

It is the hope of the Safety Committee that old and new players alike will be made to make an educated decision when purchasing their first polo helmet or replacing their old polo helmet. The number to remember is 1100. Under 1100, the helmet is safe; over 1100 the higher the risks of severe brain injury if one where to have a collision. There are currently some relatively safe cosmetically appealing helmets in the retail stores throughout the country. We believe that purchasing helmets that have not undergone standard testing procedures should be avoided.

We recommend that facial protection be part of the annamentaria when purchasing a helmet. Thus far, we feel that the present stainless steel facemask is far superior than wearing no facemask at all. Although goggles are becoming more popular, we thus far do not have a goggle that will withstand the impact of a polo ball traveling at 84 miles/hour.

1998 Helmet Safety Tests -- Wayne State Bioengineering Lab

HELMET

FRONT

SIDE

REAR

TOP

DATE

RATING

Patey

1638

589

949

1181

1998

 

Grattan*

1401

647

1614

1244

1988

 

Argentine

3270

1903

3059

2509

1998

 

Polo USA*

3263

818

1585

1380

1998

 

Polo USA

1806

1145

2708

2420

1988

 

Bond St.

959

858

964

648

1998

2

Spectra

1181

804

1278

965

1998

--

Falcone2*

1291

938

1885

1188

1998

 

Falcone1*

1131

691

1064

1114

1998

--

Bond St.98

740/1028

595/584

806/1078

598/975

1998

1

Spectra2*

1259

770

1197

1160

1998

--

Lexington (Hunt Cap)

1500

1680

2099

1554

1998

 

Bell Hard shell motorcycle

1349

1056

1751

1264

1999

 

Polo Gear 98*

1161

801

1202

939

1998

 

Polo 2000

1212

457/707

842/1064

640/1003

1998

3

Severity Index

* When the same helmet was re-tested, the Severity Index results were dramatically worse. This suggests those helmets that tested well (1100 or below initially) should be discarded after a severe blow to the helmet.

Helmets no longer manufactured are the Lodsworth, Townsend, Cowdray and the Bell Pacer.


The Game of Polo

A polo match lasts about one and one-half hours and is divided into six 7-minute periods or chukkers. Since a horse in fast polo can cover two and one-half to three miles per period, he’ll be too tired to play a second one right away. After resting for two or three periods, some horses can return to the game. Still, in championship polo, a player will come to the field with at least six horses. The mounts are horses, mostly thoroughbreds, not ponies.

The object of the game is to score as many goals as possible.

There are four players on a team and each assumes a specific position — either offensive or defensive. However, given the enormous size of the playing field (160 x 300 yards), the momentum of the galloping horses and the ball’s unexpected changes of direction, the game is very fluid, hence positions continuously change.

There are few set plays in polo, and good anticipation necessitates almost a sixth sense. With thousand pound animals running at speed there is a pre-eminent necessity for a right of way rule. The central concept in the rules of polo is the line of the ball, a right-of-way established by the path of the traveling ball. Like the rules of the road, there are dos and don’ts governing access to this right-of-way and crossing it.

Within these limitations, a player can hook an opponent’s mallet, push him off the line, bump him with his horse or steal the ball from him. Penalties are awarded as free hits. The more severe, the shorter the distance to the goal mouth. The closer hits are almost certain goals. After every goal is scored, the teams change sides in order to compensate for field and wind conditions.

A typical score would be 10-7. Polo games are played on the flat or the handicap. Every registered player is awarded a skill rating from C (-2, the lowest) to 10 (the highest). Only a handful of U.S. players are rated above 6. When a match is played on the handicap basis, the sum total rating of the players on the team is subtracted from that of the opposition. Any difference is then awarded to the lower rated side in goals on the scoreboard. Two mounted umpires on the field and a referee in the stands officiate the games.


From the AMEA President

Dr Janet Friesen

There is a great deal of work to do for those of us concerned about safer riding practices. A recent cattle-penning event reflects this state of affairs. I wore an ASTM/SEI approved helmet in the winning 29-second run, but my teammates were wearing the popular baseball caps often sported by Western riders. It is important that each of us set an example for other riders even if we appear "out of fashion".

As another example, when I participated in an AQHA sanctioned cattle penning event, I was required to receive special permission to wear a helmet. The rules called for the traditional cowboy hat.

Finally, in the last issue of the AMEA News a graphic of a Foxhunter wearing a helmet without a chinstrap was depicted. Although this was artwork and not an actual picture, this, unfortunately, is also a common practice. Wearing a helmet with a chinstrap but not securing it is common with jumpers in the warm-up area. Injuries can occur anytime, anywhere.

On a happier note, memberships are coming in nicely and there is a great deal of interest in committee work in the areas of Education, Research and Resource. Thank-you to all of the members who have expressed their willingness to serve on the committees and to all of you for publicly supporting safety in riding. We are also looking for any other input and questions for our Q&A articles.

We are attempting to increase AMEA exposure at equestrian events and LaJuan is doing an excellent job of this.

The Board has determined that we will not hold a Medical Symposium in 2001. The board had been in discussions and considered offering the meeting every two years in order to assure that we can provide an excellent program that is also well attended. The final decision of the board is that we will hold meetings every two years beginning in 2002. Plans are now underway for an annual meeting and medical symposium to be held in the fall of 2002, in Atlanta, Georgia. We will keep you apprised of the details through this newsletter.

Happy Trails,

Janet M. Friesen MD
President, AMEA


 

SAFETY ALERT

Equestrian Helmet

Please be advised that the GPA Riding Helmet is not certified or approved by SEI— the Safety Equipment Institute. An equestrian industry catalog inadvertently included a claim of "ASTM F1163.99/SEI Approved" for GPA riding helmet. This is an incorrect statement, as this helmet is not certified

The SEI homepage is located at http://www.SEInet.org/ To view the complete list of SEI certified equestrian helmets you can click on the button Certified Product list, find the equestrian helmet listing in the table of contents, click on that heading, or go directly by using this address: www.SEInet.org/CPL/astm1163.htm

Email inquiries should be sent to info@SEInet.org


 

Pardon Us

Dear Members

In the last edition of the AMEA News, artwork appeared alongside the Masters of Foxhounds Association Survey Results article (Page 10) which depicted a helmeted rider.

It was brought to the attention of the editorial staff, after publication, that it appeared in the artwork that the rider, although helmeted, did not have a properly fitted and secured chinstrap. It is the opinion of this association that the chinstrap is a vital part of a properly fitted and secured helmet.

We regret this error and apologize to those who may have found this to be offensive.

La Juan Skiver
Managing Editor


 

Fact Sheet: Horses and Children

Population at Risk

The American Horse council has reported that there were 258,400 youth involved in 4-H horse and pony programs in 1994 and 13,000 youth members of the United States Pony Clubs.[1] The numbers of youth at risk for horse-related injury are much greater than these numbers suggest because many children who are involved with horse-related activities are not members of equestrian organizations.

The American Horse Council estimates that there are 1.9 million horse owners in the United States; 3.6 million persons are involved in showing; and 4.3 million in recreational activities. Approximately 619,400 persons are directly employed by the horse industry.[2]

The most common group receiving treatment for equestrian-related injury is young female riders.[3,4] It has not been determined whether this is attributable to the ratio of female to male youth riders or other factors.

A 1991 survey reported that more girls than boys and more children involved in English style riding than Western wore helmets regularly. Reliable information on helmet use among occasional riders is not available.[5]

The most common cause of death and serious injury in all riders is head injury; the percentage of these injuries causing death and serious injury is higher in young riders.[3,6]

Cost of Injury

The cost of horse-related injuries among children and adults younger than 25 years seen in emergency departments in 1996 is estimated at over $88 million. The average cost per injury is estimated at $7,410.[7]

National Injury Estimates

In 1997, an estimated 23,710 emergency department visits were made by individuals in the United States younger than 25 years as a result of horse-related injury included contusions, fractures, and strains and involved distribution of injury to the head/neck (22%), upper body (54%), lower body (21%), and not specified (3).[8]

Selected Studies

Emergency department studies show that a high percentage of equestrian injuries are serious, with up to 38% (dependent upon study cited) resulting in hospitalization and 28% to 48% involving fracture.[3]

In a national analysis of sports and recreational injuries, the highest proportion of injury events resulting in multiple injures occurred as a result of riding animals â€" a higher proportion than bicycling, in-line skating, or sports-related falls.[9]

Up to 90% of serious injuries to equestrians that required hospitalization are caused by being separated from (e.g. propelled from or fall off) the horse while riding or by falling with the horse.[3]

Many children are injured during non-riding activities such as leading, grooming, and feeding.[10] In one study, 20% of the children hospitalized for severe head and facial trauma, had been kicked by a horse.[6]

A population-based study in rural Wisconsin revealed that 30% of those younger than 19 years who sought treatment for horse-related injuries were injured while engaged in non-riding, horse-related activities. The injury rate for children in this study was 5.6 per 10,000-person years.[11]

In a review of 1,330 injury cases involving horses in Australia, children accounted for 35% of the cases. The age group with the greatest number of injuries was the 10-19 year olds, primarily females.[12]

A survey of 2,195 frequent riders showed a history of hospitalization and prolonged disability among injured equestrians.[13]

A study of 557 frequent riders younger than 25 years estimated an injury rate of 0.6 per 1,000 riding hours.[14] In contrast, the overall injury rate for persons age 15-24 years is 0.05 per 1,000 working hours.[15]

In one survey, approximately two-thirds of the injuries were attributed to the horse's behavior, with "spooking" being the most common horse behavior. Additional primary causes were attributed to human behavior or practices.[5]

Prevention

The evidence is overwhelming that consistent use of secured, ASTM* standard, SEI** certified equestrian helmets will decrease equestrian deaths and serious head injuries.[3,8,16,13,17,18]

Bicycle helmets reduce traumatic brain injuries in bicyclists by 88%.19 The effectiveness of ASTM/SEI equestrian helmets is estimated to be comparable.[17]

The American Academy of Pediatrics (AAP) recommends that young riders in all organizations and activities that promote or sanction horseback riding wear helmets that meet the 1988 ASTM testing standard as certified by SEI when riding horses.[20]

Young riders should be supervised and matched with horses appropriate for their levels of cognitive development and riding ability.[20]

*American Society of Testing Materials, ASTM F-1163

**Safety Equipment Institute, SEI

References

1. American Horse Council. Horse Industry Directory. Washington (DC); 1996.

2. American Horse Council. Horse Industry Directory. Washington (DC); 1998.

3. Nelson DE, Bixby-Hammett D. Equestrian injuries in children and young adults. American Journal of Diseases of Children 1992; 146:611-614.

4. Chitnavis JP, Gibbons CLMH, Hirigoyen M, Lloyd Parry J, Simpson AHRW. Accidents with horses: What has changed in 20 years? Injury 1996; 27(2):103-105.

5. Thompson JM, Von Hollen B. Causes of horse-related injuries in a rural western community. Canadian Family Physician 1996; 42:1103-1109.

6. Barone GW, Rodgers BM. Pediatric equestrian injuries: A 14-year review. The Journal of Trauma 1989; 29(2):245-247.

7. U.S. Consumer Product Safety Commission. Cost estimate injury model for 0-24 year olds emergency room injuries on horseback 1996. Washington (DC): National Electronic Injury Surveillance System; 1997.

8. U.S. Consumer Product Safety Commission. Preliminary data horseback riding injuries ages 0-24 1997. Washington, (DC): National Electronic Injury Surveillance System; 1998.

9. Bijur PE, Trumble A, Harel Y, Overpeck MD, Jones D, Scheidt PC. Sports and recreation injuries in U.S. children and adolescents. Archives of Adolescent Medicine 1995; 149:1009-1016.

10. Firth JL. Equestrian injuries. (1985). In: Schneider RC, Kennedy JC, Plant ML. eds. Sports injuries: Mechanism, prevention and treatment. Baltimore, MD: Williams and Wilkins, 431-439.

11. Young NB, Stueland DT, Berg R, Follen M, Wittman L. Surveillance of riding and non-riding equestrian injuries at a rural medical center. Poster presented at American Public Health Association Annual Meeting, 1996.

12. Williams F, Ashby K. Horse related injuries. Victorian injury surveillance system. Hazard 1995; 23:1-13.

13. Nelson DE, Rivara RP, Condie C, Smith S. Injuries in equestrian sports. The Physician and Sportsmedicine 1994; 22(10).

14. Christey GL, Nelson DE, Rivara FP, Smith SM, Condie C. Horseback riding injuries among children and young adults. The Journal of Family Practice 1994; 39(2).

15. Computation from annual injury rates in Rice P, MacKenzie DP, Associates. Cost of Injury in the United States: A Report to Congress; 1989.

16. Aronson H, Tough SC. Horse-related fatalities in the Province of Alberta, 1975-1990. The American Journal of Forensic Medicine and Pathology 1993; 14(1):28-30.

17. Centers of Disease Control and Prevention. Injuries associated with horseback riding: United States, 1987 and 1988. MMWR 1990; 39(20):329-332.

18. Bond GR, Christoph RA, Rodgers BM. Pediatric equestrian injuries: Assessing the impact of helmet use. Pediatrics 1995; 95(4):487-489.

19. Thompson RS, Rivara FP, Thompson DC. A case-control study of the effectiveness of bicycle helmets. New England Journal of Medicine 1989; 320:1361-7.

20. American Academy of Pediatrics. Horseback riding and head injuries (Statement from the Committee on Sports Medicine and Fitness). Pediatrics 1992; 89(3):512.

For more information:

National Children's Center for Rural and Agricultural Health and Safety
Marshfield Clinic
1000 North Oak Avenue
Marshfield, WI 54449
1-888-924-SAFE (7233)
Fax 715-389-4996
E-mail: nccrahs@mfldclin.edu
http://research.marshfieldclinic.org.children/


 

From the AMEA Library...

Photocopies of the following are available from the AMEA office. Although there is no charge for the article please remit a donation of $1.00 per item requested to assist in defraying the cost of photocopying and postage.

Please send your request to

La Juan Skiver
c/o AMEA
5318 Old Bullard Rd.
Tyler Texas 75703

1. Accidents in Equestrian Sports (1987 Dr. Doris Bixby-Hammett) - findings and comments of five year study of accidents occurring in six-21 year old riders.

2. Alcohol Use and Riding Fatalities in North Carolina from 1979-1989- (reported by DB Hammett)-

3. Approved Helmets Building Safety into Tradition- (1984 Kristi Lee Johnson) ...Approved safety helmets are becoming required wear. While riders protect their heads, retailers could protect their sales by having approved headwear in stock

4. Injuries Associated with Horseback Riding U.S. 87-88 (Center for Disease Control, exc.> Morbidity and Mortality Weekly Report) includes chart with age, location and diagnosis percentages.

5. Equestrian Injuries in Children and Young Adults (1992 David E Nelson MD, MPH Doris Bixby Hammett, MD) authors reviewed the English language scientific literature about equestrian injuries among children and young adults...with references

6. Equestrian Injuries (Arthur M Bernhang, MD Georgine Winslett, BA) study of American Horse Shows Association and United States Pony Clubs horse shows to try and determine if shows are as safe or safer than other sports...accident rate...factors that influence accident...types of accidents and injury.

7. Head and Neck Injuries in Equestrian Sports (1993 Doris Bixby Hammett, MD) presented at the ASTM Symposium May 20,1993

8. Head and Spinal Injuries Associated with Equestrian Sports: Mechanisms and Prevention (William H Brooks, MD Doris Bixby-Hammett, MD)

9. Helmets and Horseback Riders (1994 David E Nelson, MD,MPH Frederick P Rivara, MD, MPH Corrine Condie, MEcon) To determine patterns of helmet use and attitudes towards helmets among horseback riders... data analyzed from subset of data from a cross-sectional mail survey of riders conducted in 1991.

10. Horse Related Deaths in North Carolina 1978-1999 (2000 Doris Bixby Hammett, MD) article and charts compiled from Medical Examiners reports for the state of North Carolina.

11. Human First Aid (1991) Presented at the United States Pony Club Annual Meeting February 1991.

12. May 25,1990/Vol 39/No.20 MMWR (Morbidity and Mortality Weekly Report) complete report includes Injuries Associated with Horseback Riding 1987-1988

13. Injuries in Equestrian Sports (1994)

14. Nervous System Injuries in Riding Accidents (1993 Mark G Hamilton, MDCM, FRCSC & Bruce I Tanmer, MD, FRCSC, DABNS) A review of 156 horseback riding accidents that occurred in southern Alberta over a 6-year period and resulted in nervous system trauma, including 11 deaths is presented.

15. Lethal Horse-riding Injuries (1989 Hans Ingemarson, MD DM.Sci Sven Grevsten, MD DM.Sci & Lars Thoren, MD PH.D. ) From the years 1969 through 1982 a series of 53 lethal riding injuries is analyzed with reference to the rider, the horse, and the environment.

16. Neurologic Injuries in Equestrian Sports (1989 Doris M Bixby Hammett and William H Brooks)

17. Pediatric Equestrian Injury (1992 Doris M Bixby-Hammett MD) Using data from sources, horse-related injuries are summarized for persons younger than 25 years of age.

18. Pediatric Equestrian Injuries- A 14 year review (1989)

19. Horseback Riding-Associated Traumatic Brain Injuries- Oklahoma 1992-94 (1996)

20. United States Pony Club 10-year Accident Study 1982-1991 (1992 Doris Bixby Hammett, MD USPC Safety Committee) The USPC conducted a ten year study of accidents occurring during its activities programs to determine when accidents occur, if they could have been prevented and if changes should be made in the overall program

21. Youth Accidents with Horses (1985 Doris M Bixby Hammett, MD) A two-year studies of injuries to youth horseback riders in 13,428,000 hours of horse activities by 18,408 US Pony Clubs.

22. AMEA NEWS 2000 Issues: Please specify February, June, September or December back issue.

23. The Instructor (2000 quarterly publication of Certified Horsemanship Association) Please specify January, March, June, September, January 2001 issue)

24. The International Eventing Safety Committee Report 2000 (2000)

25. Nature VS Nurture: Beyond Helmets are Uncomfortable (2000 Lorree Probert, Occupational Safety & Health Administration)

26. Biokentics Ltd. review Equestrian Headgear (2000 Horse Council of British Columbia) The Canadian Equestrian Federation requested Biokentics and Assoc. LTD to review equestrian headgear standards in order to specify certification levels for headgear use in sanctioned events. This report contains outcomes of the testing.

27. Horse-Related Fatalities in Ohio 1990-1998 (George H Koepke, MD) Information for report is taken from review of death certificates issued during the nine year period

28. Pediatric Horse-Related Injuries in New Mexico (Robert E Sapien MD, FAAP Lenora M Olson, MA David P Sklar, MD, FACEP) A retrospective review of children with horse-related injuries admitted to the states only Level 1 Trauma Center. Horse-related injuries were the second leading cause of pediatric trauma admissions to our institution....with references and tables

29. After Traumatic Brain Injury (Maureane Hoffman, MD PhD) Women appear to suffer worse outcomes than men after traumatic brain injury. This report excerpted from A Metaanalysis of Gender Differences in Outcome after Traumatic Brain Injury. ...with references

30. Equestrian Injuries in Baby Boomers (2000 Robert Stanton, MD) This growing, aging, active group of athletes is expected to suffer more than 1 million sports related injuries(this year) Many of those will be horse-related. ...medical comment 1/2 page summary

31. National Electronic Surveillance System: Preliminary Report 1999: (2000 Doris Bixby Hammett, MD) NEISS provides figures on horse related injuries that go to hospital emergency rooms over the nation. ...Charts, tables, references...


 

"An experimental model of sudden death due to low-energy chest-wall impact (commotio cordis)"

Editorial

The New England Journal of Medicine, June 18, 1998, on Link MS, Wang PJ. Pandian NG, et al

In this issue of the Journal, Link et al. provide direct evidence that ventricular fibrillation is the cause of most fatal cases of commotio cordis. The investigators developed an experimental model of commotio cordis in anesthetized juvenile pigs. Although animal studies are not often published in the Journal, this study contains unique, clinically relevant information that could not have been obtained in human subjects. The authors constructed a device that delivered controlled impacts to the chest, simulating the impact of a baseball thrown at moderate velocity. The impacts were gated to the electrocardiogram so they could be precisely timed to particular phases of the cardiac cycle. When the impacts were delivered within a narrow temporal window between 30 and 15 msec before the peak of the T wave, ventricular fibrillation was reproducibly induced. The vulnerable period of the cardiac cycle amounted to just over 1/100 of a second. Remarkably, ventricular fibrillation was immediate, occurring on the very next heartbeat. The arrhythmia was not produced by impacts at any other time during the cardiac cycle, although transient complete heart block was sometimes observed with impacts during the QRS complex. Occasionally, with impacts delivered just outside the 15-msec period of vulnerability, unsustained polymorphic ventricular tachycardia was seen.

Comment:

There are numerous reports of low-energy, as well as high impact, lethal injuries to the chest among children and adults. Several authors have recommended the use of chest protectors to possibly reduce the number of deaths among young athletes. A review of coroner’s reports of 80 horse-related deaths in Ohio revealed that two were caused by commotio cordis as a result of a kick in the chest. Knowing that sudden death is likely if a low impact blow to the chest is given during a brief period of 1/100th of a second of the cardiac cycle, perhaps a chest protector might be life saving to equestrians working with young horses.

George H. Koepke, M.D.


 

Medical Implications

Masters of Foxhounds Association

Covertside Survey, March 2000

Doris Bixby Hammett, MD

Editor’s Note: This article contains expanded information that was derived from the Masters of Foxhounds Association Survey results. A portion of this report was featured in the December AMEA News (page 10, Vol. XI Number 4.)

Norman Fine, Editor of Covertside, the magazine of the Masters of Foxhounds Association (MFHA) with a readership of 18,000, realized that the members of the Masters of Foxhounds Association possessed years of riding experience and tradition. They could provide a valuable contribution of information to the horse community and its understanding and willingness to use standardized, certified, fitted, and secured protective headgear.

Method

A questionnaire was published in Covertside in March 2000, asking the readers to respond if they had fallen during the last two years hitting their head. These are the results of the thoughtful responses that were returned.

Two hundred questionnaires were returned; one was incomplete, one not signed, and in one the accident was before the two years to be covered giving 197 responses.

Results

The fall occurred during hunting in 53.8%, while hacking or exercising in 32%, with "other" forming the remainder. The rider’s head hit the ground in 75% and a paved road in 4.6% with all others less. The riders head hit the horses hoof in 2% of falls, but 8.7% were stepped on (9), kicked (7), and one was both stepped on and kicked.

The rider was confused or disoriented after the fall in 59.4% of cases. Of these 35% were confused/disoriented less than 5 minutes, 25.6% 5 to 30 minutes, 18.8% over 30 minutes to one hour with 17.9% longer than one hour and one death. Of those confused or disoriented longer than one hour (21), 47.6% 2-3 hours, 28.6% 4 to 8 hours, 9.5% 1 to 3 days, and 14.3% 3 week to 6 months.

The riders remembered the fall in 80% of the accidents. The rider was unconscious in 33.5% (66) of the falls. Of these 66 riders, 51.5% were unconscious less than 5 minutes, 37.9% 5 to 30 minutes, 1.5% longer than 30 minutes to 1 hour, and 9.1% were unconscious longer than one hour (over 1 to 24 hours.). There was one death. Of these 66 persons who felt they were unconscious, 66.7% were examined by a medical professional. Of the persons who fell, 36.5% were seen in an Emergency Room. There were four persons who felt they were concussed seen in the emergency room, but a diagnosis of concussion was not made.

Of those who were injured, 54.5% experienced headache, dizziness, nausea or double vision. Of these 107 persons, 21.5% experienced these symptoms for less than one hour, 31.8% up to one day, 23.4% up to one week, 11.2% up to one month, and 12.1% longer. Of these (13) three experienced symptoms for up to 3 months, four for three months, 2 persons 6 to 8 months, 2 persons 1-2 years, one for one year (until her double vision was corrected by surgery) and one died. Of these who experienced symptoms, 17% returned to the hunt the same day, 23% returned within a week, 25% returned after one week but before 1 month, 16% returned between one month and 6 months, 17% returned after 6 months, and 2% did not return to hunting of which one died.

Of those who were unconscious, 7.7% returned to the hunt the same day, 20% returned within a week, 30.8% returned after one week but before 1 month, 18.5% returned between one month and 6 months, 20% returned after 6 months, and 3.1% never hunted again. Symptoms remain with 8.9% of those who hit their head.

Of the 36.5% (72) who were seen in an emergency room, 42 were unconscious. Of those injured, 12.2% were admitted to the hospital.

All but two wore a hard hat. Of these two one wore a top hat and one wore a soft cap. Of those who wore a hard hat, 88.7% had a harness. Of these hats with a harness (173) 79.4% (135) were American Standard Testing and Materials (ASTM) standard. All said that if they had a harness, it was fastened correctly. Of those hats with a harness, 14.5% used a chin cup and 85.5% were under the chin. If the harness used a chin cup, 52% suffered dizziness, confusion and nausea. If the harness was under the chin, 56.5% suffered the same symptoms. If the harness used a chin cup, 32% suffered unconsciousness and if the harness used a strap under the chin 34.7% suffered unconsciousness.

The ages varied from 12 to 86 years old. The percent was: 5-14 years 2%; 15-24 years 3.1%; 25-44 years 25.5%; 45-64 years 62.2% with 7.1% over age 65 years. Of those 5-14 years old, 25% suffered unconsciousness; between the 15-24 years 50% suffered unconsciousness: 25-44 years 26%; 45-65 years 32% and over 65 years the incidence of concussion was 64.3%

The years hunting varied from those who never hunted, to those who had hunted over 40 years. Five (2.5%) of the injured said they never hunted, 16.8% hunted for first time to 4 years; 24.4% from 5 - 10 years; 16.8% from 11-19 years; 17.8% from 20-29 years; 15.2% from 30-39 years and 6.6% over 40 years in the hunt field.

Of those in which the gender was known, 61.8% were female. If you were female you were 37.3% likely to have a head injury, and if you were male your chances were 30.9%.

Discussion

In 1981-1982 a study of fox hunting reported concussions were 18% of all injuries. At that time 81% of riders wore traditional hunt caps (hard hats without harness), 13% wore bowlers and 6% top hats. The average age of riders who sustained a concussion was 46 years (range, 25 to 60).[1]

What we did not learn

The premise of this survey was to determine if helmets improved the safety of those who use them. The figures of the study are not adequate to make a conclusion from them Only two respondents did not wear a hard hat giving inadequate numbers to compare with the 195 who did. A hard hat with a harness was worn by 173 of the respondents leaving only 22 who wore a hard hat without a harness. Again, the figures from these 22 are not sufficient to compare with the 173 who wore a hard hat with a harness. The only death was in a rider who was wearing a hard hat without a harness. Of the 173 riders who had a hat with a harness, 135 had ASTM equestrian standard helmet, leaving again only 38 replies to compare.

What we did learn

Of the respondents 79.4% of the riders used ASTM equestrian standard protective hats. The Masters of Foxhounds members have tradition and experience behind them. They are mature persons with 62.2% of the respondents between the ages of 45 and 64 years. Over 80% of the respondents have ridden 5 years or more, with almost 40% having ridden over 20 years. Their members show that they are concerned for their safety and that age and years of riding does not bar them from decisions relative to protective headgear. The comparison of the use of hats in 1981-1982 marks this change.

Of those who had ASTM helmets, 5 had hats 5 years or older. ASTM hats should be replaced after 5 years, as this is the life span of the protective liner. Where the hat was possibly damaged in the fall, only 31 (23.7%) returned the hat to the manufacturer. As damage to the hat may not be seen on inspection, the manufacturers ask that any hat that has been on a head hit in a fall be returned to them. The hat will be replaced at a minimum charge and the manufacturer will be able to see how the hat functioned in the fall.

Medical implications

The absence of medical care gives concern. Of the respondents, only one third were examined by a medical professional. Of those injured, only 36.5% were seen in an emergency room. Brain injury is one of the most serious of injuries of the human body. To see this injury treated with this cavalier attitude is distressing. However, this is but half of the problem. With the exception of the death, the other injuries fall into the category of minimal traumatic brain injury.

X-ray, MRI, sonogram, and electroencephalogram can locate widespread injury but minimal traumatic brain injury (MTBI) is easily overlooked. The American Academy of Neurology gives three considerations in management of the persons with a concussion. First, immediate neurologic emergencies must be identified. Second, prevention of catastrophic outcome from second impact syndrome (which results from a second concussive insult closely following the first). Finally, cumulative and chronic brain injury from repeated concussions should be avoided as the cumulative effects have been implicated in cognitive impairment as well as poorer neuropsychological function in those studied. Experiencing two or more prior concussions is associated with an attenuation of cognitive skills, which are executive functioning, and speed of information processing.[2]

The American Academy of Neurology Practice Parameters diagnosis of MTBI concussion is:

1. Grade 1 concussion (mental status abnormalities resolved within 15 minutes).

2. Grade 2 concussion (mental status abnormalities lasting longer than 15 minutes, but resolved within 45 minutes)

3. Grade 3 concussion (any loss of consciousness, or abnormalities lasting longer than 45 minutes).

This definition was primarily based upon high school, college and professional athletes all of whom have lower ages than seen in approximately 90% of those responding in the MFHA study. However, with this limitation, using the definition above but including those who had no memory of the accident as Grade 3, the MFHA concussion rating was Grade one 43.1% (85) and Grade three 56.9% (112). Of these, 17 still have symptoms, one died, and one had paralysis following back injury. In preliminary pilot studies, the majority of athletes experience limited or no neuropsychological impairment and rapid resolution of symptoms.[3] Maroon did observe a post concussion syndrome in 3% of the athletes. Headache, dizziness, or difficulty with concentration characterized this syndrome. The MFHA respondents reported 8.9% presently have symptoms.

The grade rating of injury was established to determine when the concussed athlete should return to play in the contact sport. Equestrian sports are not a "contact sport" but the severity and frequency of injuries allow comparison with the parameters of contact sports. If we can consider equestrian sports equivalent to contact sports, no other contact sport has participants of the age seen in the MFHA.

Using the grading scale as outlined above, of those 2% (4) ages 5-14 years 75% were grade 3 concussions, ages 15-24 years (6 - 3.1%) 100% were Grade 3; ages 25-44 (50 25.5%) 60% were Grade 3; age 45-64 (122 - 62.2%) 51.6% were Grade 3; ages over 65 (14 - 7.1%) 71.4% were Grade 3. Although these numbers are small, they give the view that the younger participant (less than 24 years) is at greater risk for severe head injury. The second conclusion suggests that the ages 45-64 year old riders, although still at great risk (51.6%) compared with the figures on other contact sports, seem to be at least risk. Perhaps they have passed the challenge of youth. However, with increased age (above 65 years) the risk increases (71.4%). This may be a result of poorer riding from decreasing strength of aging muscles and the impaired balance of senior citizens associated with poorer mental decisions. Another cause may be that the brain at that age has had multiple insults and is more fragile with the same impact. Medical studies suggest that age increases the risk and severity of brain injury.[4]

Females have greater risk for concussion than males. Of the 110 females who responded, 69 (62.7%) had a grade 3 MTBI and of the 68 males who responded, 32 (47.1%) had a grade 3 MBTI.[5]

A self-reported history was the only available source of information in our survey. Although no questions were asked concerning total number of concussions, several comments included history of previous concussions. During the two years covered by the survey, nine persons had two head injuries and one person reported three head injuries (10/187 5.3%). A significant relationship was found between total years participating in football and total number of concussions sustained.[6] This statement probably can be made concerning the equestrian sports

It was also noted that where the reporter felt he/she had a concussion, only 2/3 were seen by a medical professional and four of these who were seen in an emergency room the diagnosis of concussion was not made by the attending medical professional.

The general medical community does not diagnose or treat Minimal Traumatic Brain Injury (MTBI) with scientific knowledge. MTBI is difficult to define. The most popular working definition is "a traumatic induced alteration in mental status that may or may not be accompanied by a loss of consciousness."[7] This definition emphasizes the poorly appreciated fact that cerebral concussions do occur without loss of consciousness and establishes that confusion and amnesia are major factors in decisions regarding whether to permit athletes to return to sports participation.

Diagnosis and treatment remain in the realm of evolving medicine. We have had no measure by which we can determine the severity or location of this type of brain injury. The symptoms of brain stem or dysfunction of its connections are unconsciousness, tinnitus, lightheadedness, unsteadiness, ataxia, headache, nausea, vomiting and incoordination. The symptoms of primarily cerebral cortex dysfunction occur acutely and are confusion, disorientation, anterograde and retrograde amnesia, decreased information processing and short-term memory impairment. Others that are delayed in onset are depression, fatigue, sleep disturbance, irritability and personality change.[8] The length of symptoms or seriousness of disability and long term residual effects cannot be accurately predicted.

Of the respondents who had a grade 3 concussion, 14% returned to hunt the same day, 27.1% returned to the hunt within 1 week, and another 22.4% returned to hunt between 1 week and 1 month. We do not know if medical advice was given to the injured rider and if it were, that it was followed.

Cantu[9] recommends under his Grade 3 concussion that the athlete may return to play in 1 month if asymptomatic at rest and exertion for 7 days. The Colorado Medical Society Guidelines for the Management of Concussion in Sports in their Grade 3 concussions recommends that the athlete be transported to the hospital for a neurological examination and observation over night. The athlete may return to play after 2 weeks if asymptomatic.[10] The American Academy of Neurology Practice Parameters Grade 3 concussion recommendations are to remove the athlete from the game and transport to the hospital for a neurological examination and observation overnight. The athlete may return to play if asymptomatic after 1 week if loss of consciousness was brief or 2 weeks if loss of consciousness was prolonged.[11] Although the majority of persons who experience a concussion are likely to recover, an as yet unknown number of these individuals may experience chronic cognitive and neurobehavioral symptoms. There are no curative medical treatments for concussion and the best management of concussion emphasizes early recognition of post-concussion symptoms and prevention of additional concussive injuries. The treatment of the head-injured equestrian does not meet these recommendations.

The present system (physical examination, MRI, CAT scan, and EEG) for identifying the person with MTBI is imprecise. The University of Pittsburgh Medicine Center (UPMC) has developed a program that gives a scientific basis for diagnosis and treatment of MTBI. The Sports Medicine Concussion Program provides information for recommendation for the time for returning to activities for athletes after sustaining an injury to the brain. The program is outlined for young adults in organized sports but should be considered by older athletes and equestrians.

UPMC in the Concussion Safety Program has developed ImPACT (Immediate Post Concussion Assessment and Cognitive Testing). The specific goals of the Concussion Safety Program are two fold:[12]

• To provide comprehensive clinical information through the use of ImPACT to assist the primary physician in making safe return to ride decisions following concussion in the rider/athlete.

• To utilize this information from a research perspective to investigate several pertinent issues regarding concussion that remain unanswered.

The ImPACT program starts with a baseline of cognitive functioning requiring 30-minute computer test using a Computerized Neuropsychological Test Battery. This test should be given to those in whom concussion might occur. If the decision were to undertake the ImPACT program by the hunt club, this baseline test would be given to the interested members. A person who has been trained in the administration of the test by a 2-hour educational program can administer the testing in groups at computer labs in schools or colleges.

If a person has a possible concussion, the injured rider or the person who is attending him/her will inform the Primary Care Provider (PCP) of the Concussion Program. If the PCP is not aware of the program and the assistance in diagnosis and care it can provide, this information is available. A retest should be done within 24 hours of the concussion injury or as soon as possible. The retest will be evaluated by the consultants at the Concussion Program who provide clinical consultation to the PCP using the first baseline evaluation of the rider for comparison. The consultants will provide a structured output data sheet outlining the rider’s scores. This data is structured to assist the PCP in making informed and objective decisions regarding return to activity. In a rider still showing abnormality on the Computerized test, the consultants will recommend follow-up intervals.

Conclusion

The Masters of Foxhounds has provided information that has not been available to the equestrian medical community by the members’ responses. This information will provide the medical community with figures showing areas of the greatest need and means by which we can improve education and safety in the equestrian activities.

Several areas of concern were identified, and a method of diagnosis and treatment of minimal traumatic brain injury was outlined.

Doris Bixby Hammett, MD
AMEA BOD Emeritus
USPC Safety Committee
103 Surrey Road
Waynesville, NC 28786

The author wishes to recognize the input of Michael Collins, Ph.D., and UPMC Sports Medicine, in preparing this article.

References

1 Harrison DC. Fox Hunting Injuries in North America. The Physician and Sportsmedicine. 12:10 Oct 84 page 130-132

2 Collins MW, Grindel SH, Lovell MR et al: Relationship between concussion and neuropsychological performance in college football players. JAMA, Vol. 282 No 10, Sept 8, 1999, Page 969

3 Maroon JC, Norwig J, Powell JW. Cerebral Concussion in Athletes: Evaluation and Neuropsychological Testing. Neurosurgery, Vol. 47, No. 3, Sept 2000, Page 665.

4 Kraus JF, Peek-Asa C, McArthur D. The Independent Effect of Gender on Outcomes Following Traumatic Brain Injury. Neurosurgical Focus 8(1). 2000.

5 Kraus JF, Peek-Asa C, McArthur D. Ibid.

6 Collins MW, Grindel SH, Lovell MR et al: Relationship between concussion and neuropsychological performance in college football players. JAMA, Vol. 282 No 10, Sept 8, 1999 Page 966

7 Collins MW, Lovell MR, Mckeag MD: Current Issues In Managing Sports-Related Concussion. JAMA, Vol. 282 No 24, Dec 22/29 1999 Pg. 2283.

8 Cantu RC: Neurosurgery, Vol. 47. No. 1 September 2000 Page 670

9 Cantu RC. When to return to contact sports after a cerebral concussion. SportsMedDigest 1988.10:1-2.

10 Colorado Medicine Society. Report of the Sports Medicine Committee. Denver 1991.

11 American Academy of Neurology, Quality Standards Subcommittee, Practice parameter, Neurology 1997, 48:581-585.

12 Lowell MR, Collins MW, Maroon J et al. The Concussion Safety Program, AMEA NEWS 11:4 Dec 2000 Page 1-3

 


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