Fall Injury Interventions

Playgrounds

Background

Playground injuries are a common source of injuries in children.11  Most of the data come from public or school playgrounds and relatively little data are available on injuries occurring on home playground equipment. Kotch and colleagues12  examined playground injuries occurring to children under the age of five at home and in day care. They found that 2% of injuries in this age group occurring at home and resulting in hospitalization occurred on playground equipment at home compared to 36% of the injuries at day care. Falls accounted for 85% of the injuries in this study. Trampolines were a frequent source of injury in their study, accounting for 1/3 of the injuries. In other studies, slides are the most frequent cause of injury for younger children and climbers for children over the age of six.13  Many studies have shown that falls off of playground equipment are the most common injuries children sustain in day care centers.14 Blaxall4, Tinsworth, 2001, found that falls were the most common cause of injury resulting in hospitalization to children under the age of 15 in the North Health Region of New Zealand. While few of these injuries are fatal, fractures do occur as do an occasional head injury.11  Head injuries, however, account for nearly one-third of admissions. These injuries are thus appropriate to prevent

The U.S. Consumer Product Safety Comm ission (CPSC) conducted a study of playground equipment-related injuries treated in U.S. hospital emergency rooms in 1999. National Electronic Injury Surveillance system (NEISS) data estimated that 205,850 public playground and home playground injuries w e re treated. Age-specific incidence rates are 29.1 injuries per 10,000 for children younger than 5 years, 34.8 per 10,000 for children 5-14 years, and 0.6 per 10,000 for those 15 years and older. Falls account for the majority of injuries. Fractures were the most commonly reported injury, with 80% of the fractures involving the wrists, lower arm and elbow. Over 75% of all injuries occurred on public playgrounds, the remainder occurred on home equipment. However, only 30% of the 147 deaths reported to CP S C in the 10-year period, 1990-2000, took place on public playgrounds. Deaths resulted from hanging, primarily from ropes, cords, clothing strings or other items tied to or entangled in the equipment (56%), falls, equipment collapse, entrapment or impact with moving components (chiefly swings), Tinsworth, 2001.

Over the past 10 years there has been a substantial increase in trampoline related injuries due to falls sustained on or off trampolines. Two-thirds of injured children are between 5-14 years of age, (Committee on Injury & Poison Prevention, Furnival 1999, Smith 1998). The most serious injuries are head and cervical spine injuries that account for 9.8% of all trampoline-related injuries,(Committee on Injury & Poison Prevention, Brown 2000). During a 6 year period (1990-1995) an estimated 249,000 trampoline - related injuries to children (95%CI, 166,300-332,500)18 years of age and younger were treated in hospital emergency rooms in the U.S. Each year an estimated 1400 children (95%CI, 800-2000) are hospitalized. The largest proportion of these injuries occur s on home trampolines,(Smith 1998). The American Academy of Pediatrics has recommended that trampolines should never be used in the home environment, routine physical education classes, or in outdoor playgrounds. Use of trampolines should be limited to supervised training programs such as competitive diving or gymnastics, (Committee on Injury & Poison Prevention).

Programs for prevention have included adding energy absorbing surfacing materials, decreasing the height of playground equipment, having regular playground inspections, and supervising children on playgrounds. Laboratory tests indicate substantial differences in the energy absorbing potential of different surfacing materials.15,16  The risk of injury is clearly related, by Newtonian mechanics, to both the height of the equipment off of which a fall occurs, as well as the energy absorbing potential of the material. Sacks and colleagues17  found that equipment greater than 6 feet (1.8 meters) in height had a higher rate of injuries than equipment less than 6 feet in height. Recent studies indicate a maximum height of 1.5m (5 ft) results in fewer injuries.

This October, 2001 update includes 7 new studies evaluating effectiveness of various types of playground surfaces and modifications of climbing structures.


Review of playground fall and injury prevention studies:

Author

La Forest, 2001

Study design and target population

Cohort study design.

Children ages 1-14 injured on public playgrounds in Montreal, Canada and receiving treatment at 2 pediatric emergency departments.

Intervention

Evaluation of height of play equipment & absorption level of playground surface. Questionnaire data from injured children and inspection of playgrounds.

Outcomes

Occurrence of injury depending on equi pment height or surface.

Severity of injury (>-AIS 2 vs. mild)

Shock absorbing properties of surfaces measured by determining surface absorption level (g-max) deceleration.

Results

Risk of injury 3 times greater (95%CI, 1.5-6.4) for fall onto a surface with g-max of 200g compared to 150g.

Injury risk 2.6 times greater on equipment higher than 2m (6.4ft), compared to 1.5m or lower.

Falling onto non-recommended type of surface increases risk of injury 2.3 times.

Study quality and conclusions

Risk of injury determined by height of equipment and surface resilience. Recommended types of surface material decrease risk of injury severity.

Maximum equipment height, 2m (6.4 ft)

Sand is recommended surface.



Author

Sibert, 2001

Study design and target population

Ecological study

Cardiff, Wales, UK

5 playgrounds improved; 14 control playgrounds; 18 month surveillance before and after changes.

Intervention

Playground improvements following surveillance program.

Bark surface depth increased to 60cm (24"); horizontal monkey bars replaced with a rope climbing frame.

Outcomes

Injury rate per observed child.

Results

Significant decrease in injury rates in 5 intervention playgrounds compared to control playgrounds p<0.003.

Playground use unchanged.

Study quality and conclusions

Good quality study. Adjusted for exposure before and after intervention. Illustrates benefits of partnership between health services surveillance and local authorities.


Author

Macarthur, 2000

Study design and target population

Case control study design.

Playground falls resulting in emergency department visits to a pediatric trauma center in Toronto, Canada 1995-1996.

Cases: severe injuries AIS 2 or greater (n=67)

Controls: minor injuries AIS 0 or 1 (n=59).

Intervention

No intervention.

Outcomes

Injury type, location & AIS score.

Information obtained from medical record, mail and telephone questionnaire and playground inspection.

Results

Cases had extremity fractures; controls facial lacerations.

73% of cases fell from height >1.5 m (5 ft) vs. 54% of controls (p=0.03).

Study quality and conclusions

Height of fall and type of undersurface are important risk factors for playground injuries.

Falls of greater than 1.5 m were associated with a 2-fold increased of severe injury compared with falls from 1.5 m (5 ft) or less.

Depth of impact absorbing surface below recommended safety standards.



Author

Roseveare, 1999

Study design and target population

Randomized controlled trial.

12 intervention (I) school playgrounds.

12 control (C) school playgrounds.

Wellington, New Zealand.

Intervention

I=Community in tervention including hazard report, engineer's report, regular contact & assistance obtaining funding.

C=hazard information only.

Outcomes

Reduction in number of hazards from baseline measures.

Results

Significant reduction of all hazards in I compared to C schools 19 months after intervention, p<0.03.

52% reduction in height hazards (I) vs 8% reduction in C schools p<0.02.

Study quality and conclusions

Use of control group adjusted for secular trend. Provision of information ineffective. Long term commitment and comprehensive programs necessary. Must also address financial barriers faced by schools.


Author

Mowat, 1998

Study design and target population

Case control study design.

Cases: children treated in emergency departments (ED) for playground injuries (n=59).

Controls: 1) children seen in ED for non-playground injuries (n=61).

2) children seen for any type of non-injury medical care.(n=68)

Kingston, Ontario, Canada.

Intervention

Playground surface, depth of surface materials, presence of handrails or guardrails according to Canadian and US safety guidelines.

Surveillance of injuries at 117 public playgrounds.

Outcomes

Any injury treated in hospital emergency rooms.

Injuries identified from CHIRPP database.

Cases matched by age, sex, day seen in ED.

Results

Multivariate analysis used.

Increased risk of injury, OR=21.0, 95%CI 3.4, 128) for use of improper surface compared to proper surface.

Increased risk of injury for falls onto appropriate surface with insufficient depth (OR=18.2 95%CI 3.3, 99.9).

Increased risk of injury if guardrails inadequate (OR=6.7 95%CI 2.6, 17.5).

Study quality and conclusions

Guidelines for playground surface materials, surface depth and use of hand rails reduce injuries.

Compliance with guidelines will reduce injuries.



Author

Mott, 1997

Study design and target population

Case control study design.

Cardiff, UK

N=300 kids ages 0-14.

Intervention

Risk factors for hazards identified.

Outcomes

Injuries treated in ED. Injury rates per observed number of children on different surfaces, types and heights of equipment.

Results

Concrete surface increases risk of injury compared to rubber type surfaces. RR=5.l 95%CI (2.1-12.5) Risk of injury or fracture due to falls from monkey bars was twice that for climbing frames and 7 times that for swings or slides.

Study quality and conclusions

Safety standards should be based on epidemiological data. Recommend removing monkey bars; keeping height of equipment to 2.5m (8 ft) and use of rubber or bark type surfacing.

Author

Witheaneachi, 1997

Study design and target population

Cross sectional survey.

Random sample of 240 playgrounds selected from 4 metropolitan and 4 rural public health units.

Sydney, Australia.

Intervention

Safety guidelines.

Outcomes

Compliance wi th guidelines for 1) fall height (2.5m).

2) type & depth of surfacing, 3) safe fall zone.

Determined by inspection.

Results

45.4% of equipment had recommended undersurface. 72% of equipment proper height, but only 1.8% of equipment met both height and undersurface guidelines.

Study quality and conclusions

Representative sample of playgrounds surveyed.

Poor compliance with safety guidelines.

None of the 240 playgrounds complied fully with guidelines.



Author

Chalmers, 1996

Study design and target population

Case control study.

Children <15 years in New Zealand.

Cases: children treated for fall injuries from playground equipment, N=110.

Controls: children who also fell from playground equipment but did not require medical attention.

Intervention

Height and surface standards for playgrounds.

Maximum fall height 2.5m (8 ft); impact absorbing surfaces.

Outcomes

Injuries requiring ED visit.

Results

Increased risk of fall injury where equipment didn't meet standards.

Falling from greater than 1.5 m (5 ft) compared to lower heights, OR=4.1 95%CI (2.3-7.6)-Falling on to hard surface compared to impact absorbing surface. OR=2.3 95%CI (1.0-5.0) Odds ratio adjusted for multiple confounders.

Study quality and conclusions

Good quality study using logistic regression to examine fall height and surface type.

Height and surfacing requirements of NZ standard are effective in preventing injury in falls from playground equipment.

Recommend maximum fall height be reduced to 1.5 m (5 ft), from current 2.5 m ( 8 ft).

 


Author

Sacks et al., 1992

Study design and target population

Randomized controlled study

Child Care Centers

66 of 71 randomly selected child care centers in intervention group and 71 randomly selected centers in the control group

Intervention

Identifying playground hazards, giving this information to the center director, providing playground safety information

Outcomes

Mean and median number of hazards per center and playground

Results

Median of 7 hazards per playground. Intervention sites had 1.3 more hazards unrelated to equipment (p=0.18) and 2.2 more equipment related hazards (p=0.16) than control playgrounds.

25% of intervention playgrounds and 32% of control playgrounds were hazardous OR=0.71, 0.39-1.29

Study quality and conclusions

Good quality RCT

Inspections and provision of information did not decrease playground hazards



Author

Sosin et al., 1993

Study design and target population

Cohort study

Approximately 90% of K-6 grade students in state of Utah

Intervention

None per se

Examined rates of injuries by type of surface and height of equipment

Outcomes

Injuries severe enough to cause at least  day of school absence or medical care

Incidence density rates calculated per equipment and surface

Results

Incidence rate was lowest for equipment over sand. Relative to sand, rate ratio for injuries were: mats=2.2 (1.38-3.58), gravel=2.1 (1.36-3.21), grass=1.7 (0.96-3.15), asphalt = 6.2 (3.27-11.87).

Study quality and conclusions

No multivariate analysis; analysis assumes equal exposure in each school for all pieces of equipment.

Sand appears to be the surfacing material with the most energy absorbing potential and the lowest risk of injury. Wood chips were not evaluated.



Author

Davidson et al., 1994

Study design and target population

Interrupted time series study

Children 5 to 16 years of age in Central Harlem compared to Washington Heights, NY

Intervention

Multi-faceted community intervention (starting in 1989) including: repair of all playgrounds, major capital improvements in 5 playgrounds and parks, painting of building murals, development of recreational programs for target age group, traffic safety programs and bicycle helmet promotion

Outcomes

Severe injuries (injuries resulting in death or hospitalization) during the intervention period (1989-1991) compared to pre-intervention period (1983-1988)

Results

Decrease in the risk of all injuries in the target age group in Central Harlem (RR = 0.74, 0.62-0.89) and in Washington Heights (RR=0.70, 0.59-0.83).

No decrease in outdoor fall injuries in the target age group in Harlem (RR=1.35, 95% 0.75-2.42) or in Washington Heights (RR=0.89, 0.49-1.54)

No decrease in all injuries in the younger (non-target) age group in Central Harlem (RR=1.06, 0.83-1.35) or in Washington Heights (RR=0.96, 0.77-1.19).

Study quality and conclusions

High quality study using objectively collected data. Timing of intervention vs. data collection is not clear. No specific data given for playground falls.

Intervention did not appear to decrease risk of outside falls.

Summary of playground injury studies:

Falls from playground equipment are responsible for 60-80% of all medically-attended playground injuries (Macarthur, 2000) Two studies recommended reducing the maximum fall height of equipment from 2.5 to 1.5 meters (Chalmers 1996; Macarthur, 2000), while a third study (Laforest 2001) recommended 2.0 meters.. Replacing monkey bars (jungle gyms) with rope climb ing frames was shown to be a successful injury reduction strategy in two studies. (Mott, 1997; Siebert, 2000) The combination of lower fall height and impact absorbing surfaces will reduce injuries.

Surfacing materials appear to play an important role in the risk of playground injuries. Laboratory tests indicate a substantial difference in the energy absorbing potential of surfacing materials. In the dry, non-frozen state, wood chips have better energy absorbing potential than sand, grass and synthetic matting.16  When wet, wood chips were better than sand and matting.15  The Sosin study provides real life data to back up the laboratory studies. These studies are fairly consistent in that sand and wood chips, to a depth of 9-12 inches (23-31cm), is the best material for decreasing the costs of injuries. Sand is by far the cheapest surfacing material; chips cost three times more than sand. The Laforest study reported an innovative method of obtaining information about the relationship between risk of injury, surface resilience, and height of equipment as well as between type of material and severity of injury by measuring playgrounds where children were injured. The Mowat study indicated that Canadian Standards Association guidelines for appropriate playground surfaces, adequate surface depth and guard or hand rails substantially reduce fall injuries.

The most important factor for the prevention of playground injuries, however, is the use of safe surface materials and the maintenance over time of the surfaces and equipment. While playground standards have been developed based on research findings, the existence of standards does not mean that they will be followed, (Consumer Federation of America 1998, Mott 1997, MMWR 1999,Witheaneachi, 1997). One study cited above found no effect of an inspection program. A New Zealand study demonstrated that an intensive multi-faceted community intervention was more effective in reducing playground hazards than providing hazard information alone. (Roseveare 1999).

The most important factor for the prevention of playground injuries, however, is the use of these materials and the maintenance over time of the surfaces and equipment. One study cited above18  found no effect of an inspection program.

Recommendations on playground injury interventions:

Surfacing materials such as sand or wood chips to a depth of 9-12 inches (23-31cm) can be recommended as effective injury prevention strategies. These must be regularly maintained. Optimal equipment height is 1.5cm (5ft).

A number of guides are available for community groups, agencies and parents on playground design:

US Consumer Product Safety Commission. Handbook for Public Playground Safety. Washington, DC: US Government Printing Office, 1991.( revised 1997)

US Consumer Product Safety Commission. Playground surfacing: technical information guide. US Government Printing Office, 1990.

  • American Society for Testing and Materials (1991). Standard specifications for impact attenuation of surface systems under and around playground equipment. ASTM F1292- 91. Philadelphia, PA.
  • Morrison ML, Fise ME (1992). Report and model law on public playground equipment and areas. Consumer Federation of America. 1424 16th Street, NW, Suite 604, Washington, DC 20036 (202) 387-6121.
  • US Consumer Product Safety Commission. Handbook for Public Playground Safety. Washington, DC: US Government Printing Office, 1991
  • US Consumer Product Safety Commission. Playground surfacing: technical information guide. US Government Printing Office, 1990.
  • American Society for Testing and Materials (1999). ASTMF 1918 Standard consumer safety performance specification for soft contained play equipment. West Conshohocken, PA.

Recommendations for future research:

Programs designed to improve community implementation of playground standards, including regular maintenance, need to be tested. Multi-faceted community programs have been successful in other areas. Innovative programs that address barriers (particularly financial barriers) to implementing playground standards need to be developed and tested.