Playground injuries: a scientific appraisal of popular concerns

Methodological Challenges in Investigating Supracondylar Fractures of the Humerus From a Child's Viewpoint: Evolution of Study Protocol

Background

Outdoor play and risk-taking behaviors, including play at heights, are important to children’s physical, social, and cognitive development. These aspects of play are important to consider when informing prevention policies for serious injuries that commonly occur on play structures. Supracondylar fractures of the humerus (SCH) are the most common type of elbow fractures that result from falls on an outstretched hand among healthy children. Despite being one of the leading causes of admission to the hospital and surgical intervention, the details surrounding the cause of these injuries are often not recorded. Previous research has correlated decreased overall playground safety with higher rates of SCH fractures. Play structure height and the type of undersurface have been identified as potential risk factors for severe injuries, including SCH fractures, in part due to low compliance with safety standards. This paper explores the challenges we encountered designing the study and the resulting insights and methodological modifications we made.

Objective

The aim of this paper is to discuss the challenges related specifically to clinical research in pediatrics and strategies developed to conduct a study that prioritizes the engagement and perspective of children and their families.

Methods

To explore the link between the severity of SCH fractures and children’s behavioral, environmental, and mechanistic factors, we conducted a mixed-methods study.

Results

During phase 1 (the original methodology) from April 2017 to July 2018, there were 58 eligible study participants and 17 were recruited. For phase 2 (the revised methodology) between October 2018 and October 2019, there were 116 eligible participants and 47 were recruited.

Conclusions

The changes in methodology made following the first phase of data collection were effective in our ability to recruit participants. By identifying and addressing challenges pertaining to recruitment and resource limitations, we were able to collect data in a concise manner while not compromising the quality of the data and make for an easily adoptable methodology for other sites interested in participating in the study. We hope that future studies that plan to employ a similar methodology can gain insight through the methodological challenges we have encountered and the way we adapted the methodology to build a more pragmatic approach.

International Registered Report Identifier (IRRID)

DERR1-10.2196/21816

Playground equipment-related extremity fractures in children presenting to US emergency departments, 2006-2016

Background

Despite updated playground equipment and improved industry standards, playgrounds remain a common source of childhood injury. Fractures account for 35% of all playground injuries presenting to emergency departments (EDs). We aimed to examine the time trends and epidemiologic patterns of playground equipment-related extremity fractures in children in the United States.

Methods

We analyzed data from the National Electronic Injury Surveillance System. Children ≤14 years presenting to US emergency departments from 2006 to 2016 with playground equipment-related injuries were included. We used weighted complex survey analysis to describe the epidemiologic patterns and severity of playground equipment-related extremity fractures and Joinpoint linear weighted regression analysis to determine trends in extremity fractures.

Results

An annual average of 72,889 children were treated in US EDs for playground equipment-related extremity fractures, yielding a national annual incidence rate of 119.2 per 100,000 children. Playground equipment-related extremity fractures accounted for 33.9% of ED presentations and 78.7% of hospitalizations for playground equipment-related injuries. Of patients with playground equipment-related extremity fractures, 11.2% had severe fractures requiring hospitalization. The annual rate of ED visits due to playground equipment-related extremity fractures remained stable (annual rate of change = 0.74, p = 0.14) from 2006 to 2016. Adjusted for age, injuries on monkey bars or climbing gyms were associated with significantly increased odds of extremity fractures in comparison to injuries from other playground equipment (adjusted odds ratio [aOR]: 2.0; 95% CI: 1.9–2.1). Overall, 49.8% of extremity fractures and 54.7% of severe extremity fractures (i.e. those requiring hospitalization) occurred on monkey bars or climbing gyms.

Conclusions

Despite enhanced playground safety standards, national rates of playground equipment-related extremity fractures have remained stable in the US. Extremity fractures remain the most common type of playground injury presenting to EDs and most commonly occur on monkey bars and climbing gyms.

Outdoor Fitness Equipment Usage Behaviors in Natural Settings

Outdoor fitness equipment (OFE) areas have become a popular form of built environment infrastructure in public open spaces as a means to improve public health through increased physical activity. However, the benefits of using OFE are not consistent, and several OFE accidents have been reported. In this study, we videotaped how OFE users operate OFE in parks and selected four types of popular OFE (the waist twister, air walker, ski machine, and waist/back massager) for video content analysis. Furthermore, we established coding schemes and compared results with the instructions provided by OFE manufacturers. The results revealed various usage behaviors for the same OFE types. In addition, we observed that a significant portion of user behaviors did not follow manufacturers' instructions, which might pose potential risks or actually cause injuries. Children are especially prone to act improperly. This study provides empirical evidence indicating the existence of potential safety risks due to inappropriate usage behaviors that might lead to accidents and injuries while using OFE. This study provides crucial information that can be used to evaluate the effectiveness of OFE and to develop future park or open space initiatives.

Composite playground safety measure to correlate the rate of supracondylar humerus fractures with safety: an ecologic study

BACKGROUND

More than 200,000 children are injured at playgrounds in the United States each year. Our goal was to introduce a composite measure of playground safety and use this instrument to correlate the incidence of supracondylar humerus fractures with playground safety in an ecologic study design.

METHODS

We used a novel "overall-safety rating," defined as a composite of 3 previously validated instruments (National Program for Playground Safety School score, surface depth compliance, and the use zone compliance) to measure the overall safety of all playgrounds within a region. The regions were rated from most to least safe based on average playground safety as measured by this new method. The incidence of supracondylar fractures was calculated using Hasbro Children's Hospital Emergency Department data and state of Rhode Island Census data from 1998 to 2006. The incidence was then correlated with playground safety as defined by our composite measure.

RESULTS

Compared with the neighborhood deemed the safest, the least safe district had 4.7 times greater odds of supracondylar humerus fracture. Overall composite safety score of the district was linearly correlated with the injury rate observed in the population at risk (R=0.98; P=0.04).

CONCLUSIONS

Using our novel composite playground safety score, we found that the incidence of supracondylar humerus fractures was increased in districts with playgrounds with lower scores, suggesting that improvements in playground infrastructure may potentially reduce the incidence of supracondylar humerus fractures, and other injuries, in children.

LEVEL OF EVIDENCE

Level IV.

Pediatric tree house-related injuries treated in emergency departments in the United States: 1990-2006

OBJECTIVES

The objective was to describe the epidemiology of tree house-related injuries in the United States among children and adolescents.

METHODS

The authors conducted a retrospective analysis using data from the National Electronic Injury Surveillance System for patients < or =19 years who were treated in an emergency department (ED) for a tree house-related injury from 1990 through 2006.

RESULTS

An estimated 47,351 patients < or =19 years of age were treated in EDs for tree house-related injuries over the 17-year study period. Fractures were the most common diagnosis (36.6%), and the upper extremities were the most commonly injured body part (38.8%). The odds of sustaining a head injury were increased for children aged <5 years. Falls were the most common injury mechanism (78.6%) and increased the odds of sustaining a fracture. Falls or jumps from a height > or =10 feet occurred in 29.3% of cases for which height of the fall/jump was recorded. Boys had significantly higher odds of falling or jumping from a height of > or =10 ft than girls, and children 10 to 19 years old also had significantly higher odds of falling or jumping from a height of > or =10 feet, compared to those 9 years old and younger. The odds of hospitalization were tripled if the patient fell or jumped from > or =10 feet and nearly tripled if the patient sustained a fracture.

CONCLUSIONS

This study examined tree house-related injuries on a national level. Tree house safety deserves special attention because of the potential for serious injury or death due to falls from great heights, as well as the absence of national or regional safety standards. The authors provide safety and prevention recommendations based on the successful standards developed for playground equipment.

Playground safety in South Western Sydney

OBJECTIVE

Recognition of the cost of injuries sustained in playgrounds has led to the development of Australian/New Zealand Standards for playground safety. This study assesses compliance of public playgrounds in South Western Sydney with the current Standards.

METHODS

Playgrounds in South Western Sydney were randomly audited for compliance with Australian/New Zealand Standards for playground equipment pertaining to fall height, type of undersurface material, adequacy of maintenance of undersurface materials and adequacy of the safe fall zone. Comparisons were made with an audit of playgrounds in New South Wales undertaken in 1995 by Kidsafe.

RESULTS

Of the 257 pieces of equipment from 87 playgrounds audited, only three (3.4%) playgrounds and 65 (25.3%) pieces of equipment complied with all criteria assessed. Compared with the 1995 study, there has been a significant improvement in equipment complying with height standards (84.4% vs 72.2%, P < 0.0001) and appropriate undersurface material (66.8% vs 45.4%, P < 0.0001). Pinebark is now the most common appropriate undersurface material used but is poorly maintained, particularly in high-traffic areas. Of 131 pieces of equipment with an appropriate undersurface material, only 38 (29%) had an adequate safe fall zone.

CONCLUSIONS

Improvements in playground safety have occurred; however, very few playgrounds meet the Australian/New Zealand Standards. Compliance with Standards pertaining to maintenance of undersurface materials and safe fall zone is poor. Mechanisms need to be developed to support councils in the upgrading and maintenance of existing playgrounds.

Comparative performance of playground surfacing materials including conditions of extreme non-compliance

OBJECTIVE

A recent case series study found that only 4.7% of 402 playgrounds in which arm fractures occurred in Victorian schools complied with the recommended 20 cm depth of tanbark. Tanbark depths at fall sites varied between 0-27 cm and the mean was 11.1 (5.0) cm. The purposes of the present study were to (1) measure impact attenuation properties of shallow and compacted depths of tanbark; (2) validate laboratory measurements with in situ data; (3) compare impact attenuation properties of compacted tanbark with an Australian manufactured rubber based surface material; and (4) study the impact performance of rubber and tanbark hybrid surfacing.

METHODS

A standard test headform was dropped on tanbark and rubber surfaces in a laboratory setting to measure peak impact deceleration and head injury criterion (HIC) values. Variations in surface depth ranged from 2 cm-20 cm (tanbark) and 2 cm-9 cm (rubber). Drop height ranged from 0.5 m-2.5 m.

RESULTS

Peak deceleration and HIC increased with increasing drop height and decreasing surface depth. Laboratory measurements at depths less than 8 cm overestimated peak deceleration and HIC values compared with in situ playground measurements. Impact attenuation of a 9 cm thick bilaminate rubber material was comparable to that of an 18 cm depth of compacted tanbark. Rubber-tanbark hybrid surfaces showed improved impact attenuation over individual surfaces.

CONCLUSIONS

Compacted tanbark of depth less than 8 cm is ineffective in attenuating playground falls, resulting in excessive impact deceleration and HIC values. Shallow and compacted tanbark found in many Victorian school playgrounds poses a high risk for severe head injury. This calls for stricter enforcement of playground surface depth compliance.

Risk factors for severe injuries associated with falls from playground equipment

A case control study design was used to determine the risk factors for severe injuries associated with falls from playground equipment. Children presenting to the Hospital for Sick Children in Toronto because of falls from playground equipment (1995-1996) were identified through daily review of admissions and emergency department visits. Cases were defined as children with a severe injury (AIS > or = 2), whereas, controls were children with a minor injury (AIS < 2). Data on age, sex, socioeconomic status, prior experience on the equipment, previous playground injury, type of equipment, height of fall, undersurface, nature of injury, body part involved, and disposition were collected via telephone interview, field trip measurement, and mailed questionnaire. A total of 126 children were studied--67 cases and 59 controls. There were no differences between the two groups on age, sex, socioeconomic status, prior exposure to the equipment, or previous playground injury. Extremity fractures predominated in the case group, while, facial lacerations predominated in the control group. The median height of fall for cases was 199 cm, compared with 160 cm for controls (P = 0.021). Cases were also more likely to have fallen from a height of > 150 cm (73%), compared with controls (54%), P = 0.027. The majority of cases (82%) and controls (86%) fell onto an impact absorbing undersurface (P = 0.540). The median depth of impact absorbing undersurface, however, for both case and control injuries was 3 cm--well below the recommended safety standards. Height of fall was an important risk factor for severe injury associated with falls from playground equipment. Above 150 cm, the risk of severe injury was increased 2-fold.

Surface stiffness affects impact force during a fall on the outstretched hand

Falls on the outstretched hand are among the most common causes of traumatic bone fracture. However, little is known regarding the biomechanical factors that affect the risk for injury during these events. In the present study, we explored how upper-extremity impact forces during forward falls are affected by modification of surface stiffness, an intervention applicable to high-risk environments such as nursing homes, playgrounds, and gymnasiums. Results from both experimental and linear biomechanical models suggest that during a fall onto an infinitely stiff surface, hand contact force is governed by a high-frequency transient (having an associated peak force Fmax1), followed by a low-frequency oscillation (having an associated lower magnitude peak force Fmax2). Practical decreases in surface stiffness attenuate Fmax1 but not Fmax2 or the magnitude of force transmitted to the shoulder. Model simulations reveal that this arises from the compliant surface's ability to decrease the velocity across the wrist damping elements at the moment of impact (which governs Fmax1) but inability to substantially reduce the peak deflection of the shoulder spring (which governs Fmax2). Comparison between model predictions and previous data on fracture force suggests that feasible compliant surface designs may prevent wrist injuries during falls from standing height or lower, because Fmax1 will be attenuated and Fmax2 will remain below injurious levels. However, such surfaces cannot prevent Fmax2 from exceeding injurious levels during falls from greater heights and therefore likely provide little protection against upper-extremity injuries in these cases.

A case-control study of risk factors for playground injuries among children in Kingston and area

OBJECTIVE

To determine the risk for injury associated with environmental hazards in public playgrounds.

SETTING

One hundred and seventeen playgrounds operated by municipalities or school boards in and around Kingston, Ontario, Canada.

METHODS

A regional surveillance database was used to identify children presenting to emergency departments who were injured on public playgrounds; each case was individually matched (by sex, age, and month of occurrence) with two controls--one non-playground injury control, and one child seen for non-injury emergency medical care. Exposure data were obtained from an audit of playgrounds conducted using Canadian and US safety guidelines. Exposure variables included the nature of playground hazards, number of hazards, frequency of play, and total family income. No difference in odds ratios (ORs) were found using the two sets of controls, which were therefore combined for subsequent analysis.

RESULTS

Multivariate analysis showed strong associations between injuries and the use of inappropriate surface materials under and around equipment (OR 21.0, 95% confidence interval (CI) 3.4 to 128.1), appropriate materials with insufficient depth (OR 18.2, 95% CI 3.3 to 99.9), and inadequate handrails or guardrails (OR 6.7, 95% CI 2.6 to 17.5).

CONCLUSION

This study confirms the validity of guidelines for playground safety relating to the type and depth of surface materials and the provision of handrails and guardrails. Compliance with these guidelines is an important means of preventing injury in childhood.

Council playgrounds in New South Wales: compliance with safety guidelines

Despite initiatives to improve the safety of play environments, playground-related injuries continue to be a major public health problem. Efforts to address playground safety in New South Wales were consolidated during 1994 through the Kidsafe Playground Safety Project. In stage 1 of the project (described here), 240 council playgrounds were assessed to determine the extent to which playground equipment complied with safety guidelines. On-site inspection of the selected playgrounds provided data on 862 separate pieces of playground equipment. Of the 723 pieces requiring undersurfacing, less than half (45.4 per cent) had the recommended type of undersurfacing while only 42 of those pieces had undersurfacing to the recommended depth. However, when the fall height of equipment was considered in addition to the undersurfacing guidelines, only 13 (1.8 per cent) of the 723 pieces of equipment simultaneously satisfied all of the safety guidelines. Regrettably, none of the 240 council playgrounds assessed complied fully with the key safety guidelines. The results underscore the need for a collaborative effort on the part of local government, Kidsafe and health promotion and regional public health units to ensure that council playgrounds in New South Wales comply with recommended safety guidelines.

Safety of surfaces and equipment for children in playgrounds

BACKGROUND

The safety of playgrounds is important to protect children from injury, but studies are mostly done mainly under laboratory conditions without epidemiological data. We investigated the safety of different playground surfaces, and types and heights of equipment in public playgrounds in the City of Cardiff, UK.

METHODS

We did a correlational study of 330 children aged between 0 and 14 years. All children were hurt when playing in playgrounds in Cardiff and presented to the Accident and Emergency Department in Cardiff Royal Infirmary during summer (April to September) 1992 and 1993, and the whole of 1994. We studied the children's hospital records to establish the type of injury and interviewed their parents to find out the playground and type of equipment involved. The main outcome measures were the number of children injured whilst playing, and injury rates per observed number of children on different surfaces, types, and heights of equipment.

FINDINGS

Children sustained significantly more injuries in playgrounds with concrete surfaces than in those with bark or rubberised surfaces (p < 0.001). Playgrounds with rubber surfaces had the lowest rate of injury, with a risk half that of bark and a fifth of that of concrete. Bark surfaces were not significantly more protective against arm fractures than concrete. Most injuries were equipment related. Injury risk due to falls from monkey bars (suspended parallel bars or rings between which children swing) was twice that for climbing-frames and seven times that for swings or slides. The height of the equipment correlated significantly with the number of fractures (p = 0.005) from falls.

INTERPRETATION

Rubber or bark surfacing is associated with a low rate of injuries and we support their use in all public playgrounds. Bark alone is insufficient, however, to prevent all injuries, particularly arm fractures. Rubberised impact-absorbing surfaces are safer than bark. We believe that playing on monkeys bars increases the risk of injury in playgrounds and that they should generally not be installed. Safety standards should be based on physical and epidemiological data. Our data suggest that the proposed raising of the maximum fall height from 2.5 m to 3.0 m in Europe is worrying.

A nursing intervention to ensure a safe playground environment

Unintentional injuries sustained on school playgrounds are a continual problem not only for children but also for the school nurses who are concerned with their safety. A group of school nurses organized by the local health department's pediatric nurse practitioner responded proactively to this problem by enlisting both school officials and students to accept joint responsibility for a safe play environment. The school nurses assisted the staff in providing a safe play environment and encouraged the students to behave in a safe and acceptable manner on the playground. The nurses developed (a) a Playground Safety Assessment Guide for the school staff to establish and maintain a safe play environment, (b) an in-service session for playground monitors to learn how to supervise children at recess, and (c) a student-oriented program for the children to improve behavior on the playground based on a program conceived by Utah State University (Daug & Fukui, 1988). School nurses and pediatric nurse practitioners can use this program as a model for other schools to improve the physical play environment and behavior of the children at recess.

Height and surfacing as risk factors for injury in falls from playground equipment: a case-control study

OBJECTIVES

Despite the widespread promotion of safety standards no epidemiological studies have adequately evaluated their effectiveness in preventing injury in falls from playground equipment. This study evaluated the effectiveness of the height and surfacing requirements of the New Zealand standard for playgrounds and playground equipment.

SETTING

Early childhood education centres and schools in two major cities in the South Island of New Zealand.

METHODS

Data were collected on 300 children aged 14 years or less who had fallen from playground equipment. Of these, 110 (cases) had sustained injury and received medical attention, while 190 (controls) had not sustained injury requiring medical attention.

RESULTS

Logistic regression models fitted to the data indicated that the risk of injury being sustained in a fall was increased if the equipment failed to comply with the maximum fall height (odds ratio (OR) = 3.0; 95% confidence interval (CI) 0.7 to 13.1), surfacing (OR = 2.3; 95% CI 1.0 to 5.0), or safe fall height (OR = 2.1; 95% CI 1.1 to 4.0) requirements. Falls from heights in excess of 1.5 metres increased the risk of injury 4.1 times that of falls from 1.5 metres or less and it was estimated that a 45% reduction in children attending emergency departments could be achieved if the maximum fall height was lowered to 1.5 metres.

CONCLUSIONS

Although the height and surfacing requirements of the New Zealand standard are effective in preventing injury in falls from playground equipment, consideration should be given to lowering the maximum permissible fall height to 1.5 metres.

Patterns of injuries to children on public playgrounds

The incidence and pattern of injuries to children in public playgrounds presenting to the accident and emergency department were reviewed over two six month summer periods in Cardiff. A total of 178 children (mean age 7.5 years) attended with a playground injury representing 1.1% of all the children attending. One hundred and five children fell from equipment, of which the commonest was the climbing frame; 125 children had playground surface related injuries, 86 on bark and 30 on concrete. The pattern of injuries on the playground surfaces was different: fractures and sprains were more common on bark surfaces and lacerations and abrasions on concrete surfaces. Comparison of total injury rates showed there were fewer injuries on modernised playgrounds than expected but these differences were not significant. Modernised playgrounds are more popular, have new exciting equipment, and offer good play opportunities for children. However, the high fracture rate on modernised bark playgrounds is concerning and requires further research.

Surface-specific fall injury rates on Utah school playgrounds

The purpose of this study was to estimate surface-specific rates of fall injuries on school playgrounds. Playground injuries related to falls from climbing equipment and the surfaces involved were identified from injury reports for 1988 to 1990 from 157 Utah elementary schools. Enrollment data and playground inspections were used to estimate student-years spent over each surface. The fall injury rates per 10,000 student-years were asphalt, 44; grass, 12; mats, 16; gravel, 15; and sand, 7. These data did not show that impact-absorbing surfaces reduce fall injuries on playgrounds better than grass. Improved field studies are needed to guide policy decisions for playground surfacing.