Sports coaches who make teenage girls do neuromuscular warm-up before practice in such sports as basketball or soccer help reduce the number of leg injuries among their athletes, researchers from the Feinberg School of Medicine, Northwestern University, Chicago, reported in Archives of Pediatrics & Adolescent Medicine.

The researchers explained as background information:

“In girls’ high school sports, injury rates per 1,000 athlete exposures are highest in soccer (2.36) and basketball (2.01). Knee injuries are the most common cause of permanent disability in female high school basketball players, accounting for up to 91 percent of season-ending injuries and 94 percent of injuries requiring surgery.”

Cynthia R. LaBella, M.D., and team set out to determine whether lower extremity injuries (leg injuries) in teenage female soccer and basketball players might be lower if neuromuscular warm-ups were done before every game or practice session.

258 sports coaches from Chicago Public Schools were invited to take part in the study. 1,492 girls and 90 coaches took part.

The coaches were randomly selected into two groups:

  • The intervention group (737 athletes) – they instituted neuromuscular warm up before each sports event
  • The control group (755 athletes) – they carried on using current warm-up procedures

The majority of the participants came from a mainly low-income part of the city.

Two weeks before the beginning of the 2006-2007 season, the coaches in the intervention group attended a two-hour training session with the lead researcher and head athletic trainer. They were shown how to carry out a 20-minute neuromuscular warm-up before each practice, as well as a shortened version before each game.

Neuromuscular training involves:

  • Progressive strengthening
  • Balance
  • Plyometric exercises – exercises where the muscles are rapidly loaded (stretched) and then contracted repeatedly. Examples include jumping high off the ground lots of times, or doing push-ups with a clap in between each one. Plyometric exercises improve muscle power.
  • Agility exercises

The coaches also taught the girls safe jumping and landing techniques which help reduce the risk of straining the anterior cruciate ligament (ACL), a common cause of knee injury.

94.7% of the 95 randomly selected coaches took part, i.e. 36 of the 80 public high schools in Chicago that offer basketball or soccer programs for girls.

Below are some data of their findings:

  • The control group – 96 leg injuries
  • The intervention group – 50 leg injuries
  • The control group – 13 girls with two leg injuries
  • The intervention group – 2 girls with two leg injuries
  • All the non-contact leg injuries that needed surgical intervention occurred only in the control group
  • There was a slightly (insignificantly) lower rate of acute-onset leg injury in teams that used warm-up more frequently

The researchers calculated that it costs approximately $80 per coach to train a group of 15 to 20 of them – making the program feasible in a mainly low-income, urban population.

According to the coaches, they used the warm-up they had been taught in an average of 80% of practices, while just 6 of the 53 intervention coaches said they used the warm-up for less than half of the practices.

The researchers did not see any prescribed practices among the control coaches. In fact, the majority of them did not warm up or had the girls warm-up or run around by themselves.

The authors concluded:

“Coach-led neuromuscular warm-up reduces noncontact lower extremity injuries in female high school soccer and basketball athletes from a mixed-ethnicity, predominantly low-income, urban population. These findings suggest that neuromuscular training should be routine in girls’ high school soccer and basketball.”

M. Alison Brooks, M.D., M.P.H., and Timothy A. McGuine, Ph.D., A.T.C., from the University of Wisconsin – Madison, wrote:

“Each year, an estimated one in three female high school athletes sustains a soccer- or basketball-related injury. In addition to the economic impact of injury, these athletes may have long-term sequelae such as joint osteoarthritis, cessation of physical activity, higher rates of chronic medical conditions and worse self-reported quality of life.

In this issue of the Archives, LaBella et al report their findings from a well-designed, large, cluster-randomized controlled trial in which they successfully implemented a coach-led neuromuscular warm-up in an underserved and at-risk population, specifically female athletes in low-income, mixed-ethnicity, urban communities. However, most coaches enrolled in the control group were observed not to include any type of warm-up routine in practice. When not part of a prescribed research intervention, coaches may not be motivated or knowledgeable to include a structured neuromuscular training program.

LaBella and colleagues did not describe why nonparticipating coaches were unsatisfied with the warm-up program, why intervention coaches omitted certain exercises, or why control coaches included no warm-up routine at all,” Brooks and McGuine continue. “This qualitative information may be key to identifying the beliefs and behaviors that are barriers to implementation of injury prevention strategies.

In their concluding statement, LaBella and colleagues state that their ‘findings suggest that NMT (neuromuscular training) should be routine in girls’ high school soccer and basketball.’ We could not agree more. But how do we get there from here?”

Written by Christian Nordqvist