NEW YORK (Reuters Health) - Soccer and rugby players who have injured their hip or groin are between two and seven times more likely to sustain another similar injury, according to a review of past studies.
Researchers looking to help explain injuries like thigh bone stress fractures and groin strains in field-based sports found that older athletes and those with weaker groin muscles were also at higher risk.
"You can't prevent age, but you can prevent the second injury by making sure the first one gets taken care of adequately and appropriately," said Dr. W. Ben Kibler.
He is medical director of the Lexington Clinic Orthopedics-Sports Medicine Center in Kentucky and was not involved in the new research.
Many professional and recreational athletes, Kibler said, don't give a first hip or groin injury enough rest and don't spend enough time rehabbing before returning to play.
"You just have to let it heal," he told Reuters Health.
Hip and groin injuries are especially common in sports that involve kicking, twisting and sudden changes in direction or speed, researchers led by Julianne Ryan from the University of Limerick in Ireland note.
They reviewed seven studies on risk factors for such injuries in field-based athletes.
The studies included a total of 1,875 soccer, rugby and Australian rules football players, from the amateur to the elite level. Athletes who were originally healthy were evaluated and followed for anywhere from one season to 10 years. All were men.
Because the studies assessed injuries in different ways, the researchers could not determine how common they were across the board.
Most of the studies reported that athletes with a previous hip or groin injury were more likely to sustain another, according to the results published May 2 in the British Journal of Sports Medicine.
Two out of three studies that looked at age as a potential risk factor found that older athletes had more injuries, and two identified weak groin muscles as a possible contributor.
Individual studies also suggested that hip range of motion and the relative strength of different muscle groups both might be linked to injury risk.
Two studies investigating athlete weight came to opposite conclusions: one suggested heavier athletes were at a higher risk of injury and the other found it was slimmer athletes that had the greatest risk. However, the researchers point out, the second of those reports was based on only 29 athletes and four chronic groin injuries. The "more robust argument," they write, is that heavier athletes are more likely to sustain a hip or groin injury than their lighter peers.
Dr. Adam Weir said researchers know very little about what predisposes people to groin injuries. But a prior injury means it's a good bet they have some of those risks factors.
"If you've already got one (injury), that means you had all these things that combined to lead you to get the injury, so you're much more likely to have one in the future," Weir, from the Aspetar Orthopaedic and Sports Medicine Hospital in Doha, Qatar, told Reuters Health.
And, he added, "Once the structure or tissue is injured, it's normally not healing to the level it was before the injury. When you put those together, that's a recipe for a high risk for getting another injury in the future."
Weir was not involved in the new review but he studies groin pain. Weir said athletes who get injured should try to make the injured area stronger than it was before the injury, prior to returning to the field.
And avoiding getting injured in the first place, through strength training and other exercises, is ideal.
Kibler said athletes whose sports involve lots of starting, stopping, cutting and twisting should make sure to get in a good warm-up and stretching session before they start playing, and then should warm down afterward.
Ryan emphasized the importance of working in some lunges, squats and other strengthening exercises.
"A lot of people overlook their strength and conditioning base at the start," she told Reuters Health. "It's important to incorporate strength training along with your aerobic sessions."
"Prevention is better than cure, and that really holds true with groin injuries," Weir said.
Br J Sports Med 2014.
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