THE PHYSICIAN AND SPORTSMEDICINE - VOL 32 - NO. 3 - MARCH 2004
Paintball Popularity Explodes
Targeting Injury and Fitness Elements
Paintball has moved from extreme to the mainstream; participation in the sport now numbers more than 8 million, according to the most recent estimate from the Sporting Goods Manufacturers Association. In 2003, a professional paintball league, the National Xball League (NXL), was formed. As further evidence of the sport's broad appeal, Dick Clark Productions recently acquired the broadcast rights to NXL games and plans to televise a celebrity paintball match.
Even sports medicine specialists, such as Brian Jacobs, MD, a sports medicine physician in South Bend, Indiana, are sampling the sport. "I reluctantly admit this: [I] have partaken in this activity twice," he says, noting that playing paintball has enabled him to observe injury patterns, which include welts from the impact of the paintball pellets and trauma from running into obstacles on the course, such as trees, other competitors, ditches, and vehicles. The sport has even spawned its own ICD-9 codes: E922.5, accidental injury caused by paintball gun; E955.7, suicide/self-inflicted injury caused by paintball gun; and E985.7, injury caused by paintball gun, undetermined whether accidentally or purposely inflicted.
The popularity of the sport and the growing accessibility of paintball parks present a fitness option that may appeal to some patients who aren't regularly active. An analysis of the aerobic demands of the sport and advice from a paintball safety expert helps physicians make appropriate recommendations to patients.
How Intense a Workout?
Tara Kammel, MS, a fitness specialist at 3M Corporate Fitness in Maplewood, Minnesota, helped conduct a study on the aerobic effects of paintball as her masters thesis while she was a graduate student in the Department of Exercise and Sport Science at the University of Wisconsin-La Crosse. The study, which has not yet been published, involved placing heart monitors on 15 paintball participants during play. Activity consisted of six games that lasted between 15 and 30 minutes. With equations that enabled them to predict VO2max levels from the heart rate data, the researchers found that playing paintball increased heart rate levels to 68% to 73% of maximum heart rate and VO2max levels between 56% and 64%. Kammel says the overall findings put the sport in the moderate activity category; however, she says paintball reaches the vigorous level during the heat of battle: when players see a target, hit an opponent, and sustain hits. Kammel says the steepness and ruggedness of the terrain also influence the intensity of the activity, as does the style and strategy of play (ie, running versus remaining in one spot and shooting).
The results suggest that, according to American College of Sports Medicine (ACSM) guidelines, paintball provides fitness benefits. Kammel adds that the nature of the sport, with its intermittent bursts of activity, dovetails nicely with ACSM recommendations to accumulate bouts of activity throughout the day.
Kammel says the running, squatting, ducking, and diving elements of the sport work the leg muscles, and carrying the equipment, aiming, and shooting work upper-body muscles. She notes that new players often report muscle soreness after their initial paintball experiences.
Bob "Sarge" Shano has been a paintball enthusiast since the mid 1980s and manages a paintball field in Portland, Oregon. He has had a first-hand look at injury patterns in the sport, and he frequently gives presentations on paintball safety.
Eye injuries. Eye trauma from paintball pellets has historically been the biggest injury concern. Though eye and head protection have evolved dramatically over the past decades, Shano says unsupervised play outside of the paintball park setting and unsafe behavior (such as taking eye protection off while on the playing field) at paintball parks presents an ongoing risk.
Contusions. Paintball impact can create painful welts and contusions when players don't wear proper clothing, Shano says. Also, the risks of more severe skin trauma increase when competitors modify their guns. "A 'hot gun' is one that is shooting over the industry-decreed safe velocity limit, which for outdoor play is 300 ft/sec," Shano says. "For indoor play and night games, the limit is substantially lower." Many paintball parks insist that before play, participants test their gun on chronographs, which measure the shooting velocity of the paintball gun. "Contrary to popular belief, the name of this game is paintball, not 'pain-ball.' Goose-egg-sized welts along with internal hemorrhaging are not deemed normal or an essential part of the game," he says.
Sprains, strains, and fractures. William O. Roberts, MD, ACSM president and associate professor in the Department of Family Practice and Community Health at the University of Minnesota in St Paul, says he's seen fewer eye injuries from paintball over the years, thanks to improvements in eye protection. He has noted a pattern of shoulder injuries in paintball players. "The usual mechanism of injury is diving for cover and spraining the acromioclavicular joint, fracturing the clavicle, or injuring the rotator cuff," Roberts says, adding that he always counsels patients on safety-equipment use.
Lower-extremity injuries can occur when players trip over tree roots or other obstacles. Though most of these injuries are minor, some can be serious. Ken Bielak, MD, a family physician in Knoxville, Tennessee, says his nephew caught his foot on a root, tumbled forward, and crushed his tibial plateau during paintball play. He says the fall tore the boy's anterior cruciate ligament and meniscus and stretched the peroneal nerve. Despite prompt treatment, the boy experienced complications, which included compartment syndrome and loss of peroneal innervation. "He now walks with a limp and requires an ankle-foot orthosis to control his foot drop," Bialek says.
Shano has several safety tips for physicians to share with their patients who are interested in paintball:
Shano believes that his safety talks are helping promote the growth of the sport. "I try to do my part by teaching others how to keep the game safe and fun for everyone to enjoy," he says.
ACEing Exercise Inspiration
The American Council on Exercise (ACE) has published a top 10 list for inspiring people to get fit.
Physicians can advise patients to:
Patricia D. Mees
Bowflex Exercise Machine Recalled
Nautilus Direct (doing business as Bowflex) in cooperation with the US Consumer Product Safety Commission (CPSC) is voluntarily recalling approximately 420,000 Bowflex fitness machines to mediate two safety concerns, according to a press release from the CPSC. Nautilus Direct and the CPSC have received at least 70 reports of the backboard benches breaking, causing at least 59 back, neck, and shoulder injuries, and at least 18 reports of the "lat tower" rotating forward and falling, causing at least 14 injuries about the head, neck, shoulders, and face, some of which required sutures.
The machines have been sold in specialty stores and in infomercials from January 1995 through December 2003 and cost between $1,200 and $1,600. Consumers are urged immediately to stop using the backboard bench in the incline position and the "lat tower" on the machines. They should also contact the Nautilus Direct toll-free line (1-888-424-3020) at any time to obtain a free repair kit designed to solve both problems. Consumers may also log onto the company's Web site (https://www.bowflex.com) for more information.
Paul W. Mamula, PhD
Tai Chi and Proprioception Benefits
Chinese researchers have found that older people who practice tai chi have better stability and knee proprioception than their peers who don't do tai chi. The study, which appeared in the December 2003 issue of Medicine & Science in Sports & Exercise, may have practical implications for physicians who want to help their older patients maintain functional activities. Tai chi emphasizes exact joint position and direction, qualities that researchers thought may heighten proprioception, which declines with age, ligament injuries, and some medical conditions (eg, osteoarthritis).
Investigators recruited 21 subjects ages 60 and older who had practiced tai chi for at least 3 years for a minimum of 1.5 hours per week. They matched the 21 tai chi participants with 21 controls. Three physical tests were used to gauge proprioception and stability: knee repositioning, static standing balance, and dynamic standing balance. The motions were recorded with various measurement devices.
Researchers found that when compared with the tai chi group, the control group had about twice the error rate on the knee repositioning test. There was no significant difference between the groups on the static standing test. On the dynamic standing test, the tai chi group had shorter reaction times, greater maximum excursion, and better directional control of movement.
The study is the second to show that tai chi improves proprioception. The previous study, performed in younger subjects, suggested that tai chi improved glenohumeral repositioning. Other studies have noted several other health benefits of tai chi, including anxiety reduction, improved mood, and improved cardiorespiratory function, muscle strength, and balance.