Recreational Injury Interventions

Soccer

Background

Soccer is a contact sport responsible for 50-60% of all sports-related injuries in Europe, Arnason et al, 1996. It is the most popular sport worldwide with approximately 240 million active players reported by the International Football Federation, and has seen increasing popularity in the United States. National participation has increased 42% compared with partcipation in the last decade leading to an increase of 33% in the number of soccer injuries reported, Francisco et al, 2000. The US Consumer Product Safety Commission through its National Electronic Injury Surveillance System, estimaed between 146,000 and 160,000 soccer-related injuries annually for the year 1992 through 1994, Committee on Sports Medicine and Fitness, 2000. Approximately 85% of these injuries occured in participants through 23 years of age, with approximately 45% occuring in participants younger than 15 years, thus indicating a need for injury prevention interventions for youth soccer athletes. Another study reported a rate of 20.11 injuries in females per 1,000 player hours in 1989 and a rate for males of 20.04 in 1988, for soccer players aged 9-19, Elias, 2001.

The majority of these injuries are to the lower extremities, involving muscle sprains, ligament strains, contusions, and fractures. Shin guards are used to prevent tibia fracture and injury to the lower leg. Francisco et al, 2000, found that the average shin guard reduced force of impact by 11-17% compared to the unguarded leg, yet there have been no randomized control trials indicating the effectiveness of shin guards in the prevention of tibia fracture. Additionaly, several prevention interventions have been examined to reduce the frequency of injury to ankles, as ankle sprains are the most common injury in both adolescent and adult female and male soccer players, Soderman et al, 2000.

Many factors, including level of competition, level of exposure, and defintion of injury, have resulted in wide variations in the incidence of soccer injuries and have made comparative analysis difficult. However, two studies below offer some evidence evaluating the effectiveness of proprioceptive training programs on balance boards to prevent soccer-related lower extremity injuries. The third study is a case-control investigation of the frequency, location, and cause of soccer injuries in Iceland.


Review of soccer studies:

Author

Soderman, et al., 2000

Study design and target population

Randomized controlled trial.

Population: 7 female soccer teams (n=121) in intervention group. 6 teams (n=100) in control group. Average age=20 years.

Intervention

Intervention group participated in special training program during 1998 season.

Program consisted of a 30 day preseason 10-15 min. balance board training and 3x week during the season.

The balance board training program was incorporated in addition to standard soccer practice and games.

Outcomes

Players and coaches recorded all traumatic injuries associated with soccer and resulting in absence from at least one scheduled practice session or game.

Range of motion, muscle flexibility, balance/postural sway of lower extremities, age, height, & weight recorded.

Results

Incidence of major injuries (RR 10.96; 95% CI 2.10-57.3) was higher in the intervention group than in the control group.

4 of 5 anterior cruciate ligament injuries occurred in intervention group.

Study quality and conclusions

Severe knee injuries in female soccer players were not prevented by balance board training.

Small sample size, due to high drop-out rate. Balance board training self-reported and done at home, and conducted over 1 only season.



Author

Caraffa, et al., 1996

Study design and target population

Non-random controlled trial.

Population: 600 soccer players in 40 semiprofessional or amateur teams in Italy.

Intervention

300 players instructed to train 20 min/day with 5 different phases of increasing difficulty in a 30 day preseason program.

300 players consisted of control group who trained "normally".

Study took place over 3 soccer seasons.

Outcomes

Anterior cruciate ligament (ACL) injuries reported.

Results

10 ACL injuries in balance board group compared to 70 in control group.

0.15 injuries per team/season for balance board group compared to 1.15 for control group (chi-square= 43.38 P<0.001).

Study quality and conclusions

Frequency of injuries in proprioceptively trained group showed a sevenfold reduction over the control group.

Results indicate that proprioceptive training can reduce the number of ACL injuries in soccer.

Cooperation with training program not controlled.



Author

Arnason, et al., 1996

Study design and target population

Case-control study.

Population: 10 (n=84) elite male soccer teams in Iceland. Mean age 25, range 18-34 years.

Intervention

Data collected for 1991 season in Iceland, through player questionnaires, and training diary kept by coach for every practice session and game.

Outcomes

Injury defined as: a soccer player is injurred if he was unable to participate in a match or training session because of an injury incurred in soccer.

Injuries classified in 4 categories regarding length of absence: less than 1 week, 1-2 weeks, 2-4 weeks, and more than 4 weeks.

Frequency, cause, and location of injury reported

Results

Incidence of injury per player 34.8 + 5.7 per 1,000 game hours, and 5.9 + 1.1 per 1,000 practice hours.

29% of injuries were muscle strains, 22% ligament sprains, 20% contusions, 29% other injuries.

44% of strains & 58% of sprains were reported as reinjuries.

97% of players used shin guards in every game, 38% in every practice. Only 1 contusion reported on shin.

(P<0.01), significantly more injuries occurred on artifical turf per 1,000 hours of soccer.

Study quality and conclusions

Significantly more injuries occurred on artifrical turf than on grass or gravel..

Teams who had the longest pre-season preparation period obtained significanlty fewer injuries during the season.

Summary of soccer interventions

Results from balance board training programs is contradictory. It appears that some programs may prevent soccer-related lower extremity injuries. Players who participated in phase programs that gradually increased in difficulty and required more time training may be less likely to experience lower extremity injury.

Recommendations on soccer programs

Compliance with balance proprioceptive board training programs could be problematic, therefore training programs should be incorporated into regular practice times, especially for younger players who do not necessarily view the sport as their profession. Preseason programs may be more beneficial than programs that are implemented during the season. Public education programs and promotion of shin guard use should be incorporated into soccer programs.

Recommendations for future research

Further randomized controlled trials are needed to evaluate the efficacy of balance board training programs. Additionally, more controlled trials are needed to examine the role of shin guards and playing surfaces in soccer-related injuries. All studies should control for re-injury.