Recreational Injury Interventions

Equipment Modification

Background

Emergency department treated injuries occurring in the softball and baseball are captured via the NEISS surveillance system. In the United States, there were an estimated 321,000 ED visits during 1989 for treatment of these sports related injuries.28  A large proportion (71%) of softball related injuries are due to sliding into the bases.29  Typical base sliding injuries include abrasions, sprains, ligament strains and fractures predominately of the lower limbs. These injuries may result from poor sliding technique, judgment errors or poor physical conditioning. Breakaway bases have been suggested as a passive, environmental intervention to reduce sliding injuries. Breakaway bases release from their anchoring system when subjected to one-fifth the force needed to dislodge a stationary base. Three studies which evaluated breakaway bases are reviewed below.


Review of breakaway base studies:

Author

Sendre et al, 1994

Study design and target population

Prospective cohort study.

Population: interscholastic, intercollegiate, recreational, and intramural softball and baseball teams in the Central Michigan area over 2 seasons, 1990-91. Ages 15-48 years

Intervention

Hollywood Impact Base (HIB); a breakaway base developed in 1989. Teams in league rotated play between fields with HIB and those with standard bases.

Outcomes

All injuries resulting from sliding or base-running contact. Injury defined as an acute event that required first aid and prevented the participant from returning to play during the same practice or game.

All injuries documented by Central Michigan University sports medicine personnel or umpires and verified by investigators.

Results

1 injury per 33,159 athlete exposures with HIB compared to 4 injuries per 3,999 exposures with standard bases.

RR=0.03 (0.00-0.23)

Study quality and conclusions

Negligible injury rate using HIB compared to standard bases.

Good ascertainment of injury.



Author

Janda et al., 1993

Study design and target population

Prospective cohort study.

Population: 8 college and 11 minor league baseball teams over 2 seasons, 1990-91.

Intervention

Breakaway bases used on home fields, standard bases used at away games. Stationary bases used only in 1991 season.

Outcomes

All sliding injuries (ankle sprains, knee injuries, shoulder contusions).

Results

486 home games (breakaway bases), 498 away games (standard bases).

10 sliding injuries over 2 seasons. There were 2 injuries per 100 home games vs 8 injuries per 100 away games. RR=0.2 (0.05-0.80).

Study quality and conclusions

Use of breakaway bases reduced sliding injuries by 80%.

Managers and trainers of all teams planned to continue using breakaway bases.



Author

Janda et al., 1988

Study design and target population

Prospective cohort study.

Population: recreational softball teams in Ann Arbor, Michigan, 2 seasons. Age range 18-55 years.

Intervention

Breakaway bases vs. standard bases. Teams assigned to playing fields on a random and rotating basis.

Outcomes

All sliding injuries requiring first aid. (sprains, fractures, ligament injuries, slide abrasions).

Results

633 games played on breakaway bases, 627 on standard bases. 47 injuries, 27 (57%) were ankle sprains and fractures. Only 2 injuries on break away bases. One injury per 18.9 games on stationary base fields compared to one injury every 316.5 games on the breakaway-base fields. RR=0.04 (0.01-0.17)

Cost of 1 set of breakaway bases was $145 more than a set of standard bases ($295 vs $150).

Study quality and conclusions

Breakaway bases associated with 96% reduction in sliding injuries in recreational softball play. Use in recreational softball leagues could produce significant cost savings. Ascertainment of injuries good. All injuries recorded by field supervisor and documented by physicians.

Summary of breakaway base interventions

Evidence from three separate studies indicates that use of breakaway bases reduce sliding injuries in baseball and softball by 80-90%. The studies included players of both sexes, ages ranging from 18 to 55 and covered a broad range of skill levels, from recreational level to minor league.

Recommendations on breakaway bases

The research evidence strongly suggests that breakaway bases should be used for all levels of adult baseball and softball competition. 40 million adults play in organized softball leagues playing approximately 23 million games per year. There are 712 college and 168 minor league teams competing in organized baseball.32,33

Recommendations for future research

Studies are needed to determine whether age-appropriate breakaway bases prevent injury in organized baseball and softball for children.

2. Protective Equipment

Background

In-line skating (also known as rollerblading) has increased in popularity in the United States from 6.2 million skaters in 1991 to 22.5 million in 1995.34,35  In-line skates have 4 or 5 wheels mounted one behind the other on a frame attached to a skating boot. Speeds of 10-17 mph are common for routine cruising, and speeds of up to 30 mph are not unusual.36  Emergency room visits for in-line-skating injuries increased from 37,000 in 1993 to 100,000 in 1995. The medical care costs of these visits was $495 million per year. Children 10-14 years of age account for 60 percent of in-line skating injuries and seventy-five percent of all injuries occur to those between 5 to 24 years of age.37  Injuries tend to be severe with fractures accounting for almost half of all injuries. Wrist or forearm injuries comprise almost 40 percent of all injuries with the elbow and head being other common sites.38  One might expect protective equipment such as wrist guards, knee and elbow pads and helmets would reduce these injuries. To date there has only been one study which has evaluated these protective devices.

Review of protective equipment studies:

Author

Schieber et al., 1996

Study design and target population

Case-control study.

Population: Subjects treated for in-line skating injuries at emergency departments participating in the National Electronic Injury Surveillance System (NEISS). Time period: 12/92-7/93 (N=161)

Intervention

Wrist guards, elbow pads, knee pads, helmets

Outcomes

Wrist, elbow, knee or head injury.

Cases: skaters with injuries to wrists, elbows, knees, or head.

Controls: skaters with injuries to other parts of the body.

Results

Wrist injuries most common, 37% of all skating injuries, 2/3 of wrist injuries are fractures. Use of protective devices low among injured patients.

Odds ratio for wrist injury comparing those wearing wrist guards to those without is 0.10 (0.03-0.34) adjusted for age and sex.

Odds ratio for elbow injury comparing wearers of protective equipment to those with no protection is 0.11 (0.03-0.38) adjusted for number of lessons and trick skating. Odds ratio for knee injury for those wearing knee pads was 0.45 (0.14-1.4)

Study quality and conclusions

Wrist guards and elbow pads are effective in protecting in-line skaters against injuries. The effectiveness of helmets could not be assessed because of the small number of head injuries.

Well-designed case control study.

SUDAAN statistical software used to account for complex sampling, and logistic regression was used to adjust for confounding factors.

Summary of protective equipment interventions

Wrist guards and elbow pads are extremely effective in reducing injuries to these portions of the body. The data used in this well conducted case control study were weighted to represent national estimates of in-line skate injuries. Analysis by Schieber and colleagues35  indicates a 90 percent protective effect for these protective devices.

Recommendations on protective equipment

Community wide campaigns should be initiated to encourage in-line skaters of all ages to wear wrist guards, knee pads, elbow pads and helmets. These campaigns should be modeled after successful multi-faceted community-wide campaigns to increase helmet use.39  Helmets are extremely protective against head injuries for bicyclists even in motor vehicle-bike collisions. One would expect helmets to be protective for in-line skaters as well.

Recommendations for future research

Additional case-control studies should be carried out to evaluate the protective effect of helmets for in-line skating head injuries. The number of people participating in in-line skating is increasing each year as evidenced by the increase in emergency department treated injuries. With a larger population of injured skaters it will be possible to evaluate the protective effect of helmets and other protective devices.