Research Review By Demetry Assimakopoulos©

Date Posted:

July 2010

Study Title:

Neuromuscular Training for Sports Injury Prevention: A Systematic Review

Authors:

Hubscher M et al.

Author's Affiliations:

Department of Sports Medicine, Goethe-University, Frankfurt Germany; Department of Sports Science and Sports, University of Erlangen-Nurenberg, Erlangen Germany; Department of Sports Science, University of Darmstadt, Darmstadt Germany.

Publication Information:

Medicine and Science in Sport and Exercise 2010; 42(3): 413-421.

Background Information:

Sport and recreational injury are a large public health burden in many nations (2, 4, 12), with a total annual incidence of injuries of approximately 2 million. Sprains, dislocations and ligamentous ruptures occur at many joints - the ankle, knee, hand, elbow and shoulder are the most common of these injuries (4, 10, 17, 18). More severe injuries can result in increased morbidity and long term disability (1, 3, 5, 6). Because of their frequency and inherent risk, prevention is the primary intervention strategy.

It has been hypothesized in the past that proprioceptive and neuromuscular training (PT/NT) have a positive impact on injury risk (11, 16). However, implementing protocols which target these systems are complicated because they have a large variety of exercises and because the quality of works published in the past show variability in internal validity.

With these ideas at heart, the goal of this review (which included randomized control trials and controlled clinical trials without randomization) was to assess the effectiveness of these two exercise approaches for preventing sports injury.

Pertinent Results:

The researchers sought to find research studies which calculated the number of injuries that occurred, given that an intervention/prevention strategy was implemented. Their definition of “injury: was: any injury, occurring during practice that required medical attention and/or resulted in the loss of at least one practice session.

All studies included young adult and adolescent athletes within the age range of 12-24 who played any of the following sports: organized school sports, basketball, volleyball, soccer, team handball, hockey and floorball. The exercise interventions included balance training, agility training, stretching, plyometrics, running exercises, cutting, strength training and landing techniques.

All of the above exercises were performed on top of the usual participation in their respective sports.

The studies included analyzed either sprains, fractures, contusions, fractures and/or strains of the foot, ankle, knee, finger, low back and shoulder (7,8,14,19); lower extremity injuries including strains, ankle sprains, knee ligamentous injury and meniscus tears (15); knee injuries including MCL injuries, meniscus or other cartilaginous injury and ACL injury (9); and ankle sprain injuries (13).

An additional study examined balance performance ability under static and dynamic conditions. They performed the exercises with their eyes closed, a timed single legged stance (performed at the start of the study and biweekly for 6 weeks) and a dynamic single legged stance on an Airex balance pad. The change from baseline was the primary outcome measure.

Seven RCTs demonstrated that balance exercises or multi-intervention training are effective in reducing specific sport injuries among young adults and adolescents who play pivot sports. These sports include basketball, volleyball, soccer, team handball, hockey and floorball.

Additionally, balance training was effective in preventing ankle sprain injuries by 36%, particularly in individuals with previous history of injury (7,13). However, balance training does not reduce the incidence of ligamentous injuries of the knee, or injuries to the upper extremities. It also does not influence the severity of injuries (8).

This meta-analysis showed that multi-intervention programs are effective in reducing the risk of lower limb injury by 39%, the risk of acute knee injury by 54% (including ACL injury during practice [9]), and the risk of ankle ligamentous injuries by 50%. In addition to this, multi-intervention training proved to reduce the severity of upper limb injury and in some cases, prevent them all together (14). However, it is unclear which training component contributed the most to the reduction in injury risk.

Clinical Application & Conclusions:

Proprioception, neuromuscular control, jumping skills, flexibility, landing skills, strength and balance are all intimately involved in sport. Preventive exercise interventions are developed to modify these risk factors. This meta-analysis concludes that there is sufficient evidence to prove that balance training or multi-intervention programs may be effective in preventing injuries to the knee and ankle in adolescent and young adult ball sport athletes.

There is, however, no specific recommendation as to the training volume to produce this effect. In addition, there was no indication of the dose response to training (i.e. which volume of training provides the best effect in preventing injury and which provides the least). The researchers reached the consensus of at least 3 months of training with 1 session per week at 10 minutes per session. Also, the generalizability of this meta-analysis to other sports is unclear – more research must be done to elucidate this.

Study Methods:

Study selection:
The researchers used the following criteria: randomized control trial or non-randomized control trial; athletes that either have or have not suffered a previous injury; papers in which only the experimental group got PT/NT and; the PT/NT intervention had to be compared to either a different or no intervention.

Data analysis:
Incidence rates, relative risks and 95% confidence intervals were taken from the experimental data of each article examined. Heterogeneity was determined through the use of a Cochran Q test and the I2 statistic (defined as the percentage of total difference across studies due to heterogeneity rather than probability). A meta-analysis was performed using a set statistical significance of P< 0.05.

Study Strengths / Weaknesses:

Weaknesses:
  • The researchers did not include studies where the diagnosis was made through orthopedic tests, special imaging or surgery. This could have dramatically decreased the number of injuries that occurred in the study simply because it did not fit the operational definition of injury.
  • Strangely, no sports other than ball spots were incorporated into this analysis.
Strengths:
  • The study provides evidence that sport injury can be prevented
  • The study provides some information as to how these injuries can be prevented using training methods that all teams can use and access.

Additional References:

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  2. Belechri M, Petridou E, Kedikoglou S, Trichopoulos D; Sports Injuries European Union Group. Sports injuries among children in six European union countries. Eur J Epidemiol. 2001;17(11): 1005–12.
  3. Cheng TL, Fields CB, Brenner RA, Wright JL, Lomax T, Scheidt PC. Sports injuries: an important cause of morbidity in urban youth. Pediatrics. 2000;105(3):E32.
  4. Conn JM, Annest JL, Gilchrist J. Sports and recreation related injury episodes in the US population, 1997–99. Inj Prev. 2003; 9(2):117–23.
  5. DeHaven KE, Lintner DM. Athletic injuries: comparison by age, sport, and gender. Am J Sports Med. 1986;14(3):218–24.
  6. Eastlack ME, Axe MJ, Snyder-Mackler L. Laxity, instability, and functional outcome after ACL injury: copers versus noncopers. Med Sci Sports Exerc. 1999;31(2):210–5.
  7. Emery CA, Cassidy JD, Klassen TP, Rosychuk RJ, Rowe BH. Effectiveness of a home-based balance-training program in reducing sports-related injuries among healthy adolescents: a cluster randomized controlled trial. Can Med Assoc J. 2005;172(6):749–54.
  8. Emery CA, Rose MS, McAllister JR, Meeuwisse WH. A prevention strategy to reduce the incidence of injury in high school basketball: a cluster randomized controlled trial. Clin J Sport Med. 2007;17(1):17–24.
  9. Gilchrist J, Mandelbaum BR, Melancon H, et al. A randomized controlled trial to prevent noncontact anterior cruciate ligament injury in female collegiate soccer players. Am J Sports Med. 2008; 36(8):1476–83.
  10. Hawkins RD, Fuller CW. A prospective epidemiological study of injuries in four English professional football clubs. Br J Sports Med. 1999;33:196–203.
  11. Hrysomallis C. Relationship between balance ability, training and sports injury risk. Sports Med. 2007;37(6):547–56.
  12. Knowles SB, Marshall SW, Miller T, et al. Cost of injuries from a prospective cohort study of North Carolina high school athletes. Inj Prev. 2007;13(6):416–21.
  13. McGuine TA, Keene JS. The effect of a balance training program on the risk of ankle sprains in high school athletes. Am J Sports Med. 2006;34(7):1103–11.
  14. Olsen OE, Myklebust G, Engebretsen L, Holme I, Bahr R. Exercises to prevent lower limb injuries in youth sports: cluster randomised controlled trial. BMJ. 2005;330(7489):449.
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