Analysis of kicking motion yields surprising clues as to why
FRIDAY, July 10 (HealthDay News) -- Male and female soccer players have different patterns of injuries, and now U.S. researchers think they know why.
They used video motion analysis to examine the kicking motion in male and female soccer players, and identified gender-based distinctions in certain types of injuries, a finding that could help prevent injuries in the future.
"Prior to this kick study, there had been very little motion analysis to show what was going on during the soccer kick. We know that female soccer players face a greater risk of ACL [anterior cruciate ligament] injury and patellofemoral problems, and male players are more at risk for sports hernia. We used motion analysis to determine if the two types of players have different alignment and muscle activation that might correlate to the injury patterns," lead investigator Dr. Robert Brophy, a former resident and fellow at the Hospital for Special Surgery in New York City, said in a hospital news release.
The soccer players were filmed in a room with eight to 10 cameras aimed at different parts of the body. The images from the cameras were merged to create 3-D images of players going through the kicking motion. The images were then matched frame by frame with electrical signals from muscles recorded while the players were kicking.
Brophy and colleagues at the Hospital for Special Surgery found that, compared with females, male players have more activation in the hip flexors of their kicking leg and in the hip abductors of their supporting leg.
"The hip abductor may be protective against ACL injury, and it is interesting that its activation was markedly diminished in women," said Brophy, who is now an assistant professor in the department of orthopaedic surgery at Washington University in St. Louis. He is also head team physician for the St. Louis Athletica, a professional women's soccer club.
The researchers also found that the knee of the supporting leg in female soccer players assumes a more knock-kneed position while kicking, which puts more stress on the outside knee joint of the supporting leg.
The two gender differences identified in the study may help explain why female soccer players suffer more ACL injuries than male soccer players.
The findings were presented Thursday at the American Orthopaedic Society for Sports Medicine annual meeting, in Keystone, Colo.
The American Academy of Orthopaedic Surgeons offers soccer injury prevention tips.
-- Robert Preidt
SOURCE: Hospital for Special Surgery, news release, July 9, 2009
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