development of a multidisciplinary method to determine risk factors for arm fracture in falls from playground equipment
Rationale: previous playground injury studies were limited in their ability to determine risk factors for arm fractures, although these factors were common and expensive.
The study of bioengineering mainly focuses on head injury.
Very few epidemiology studies quantify the attenuation of surface impact, and no one investigates the results of specific injuries such as arm fractures.
Design: unparalleled housing
A control study design was developed.
To simulate the real playground waterfall, a children\'s dummy and rig with meter was designed.
Dummy verification output for quantifying arm load.
Other field measurements include equipment height, fall height, surface depth, head shape deceleration, and head injury criteria.
Discussion: combine effective methods of biochemistry and Epidemiology in a robust design.
The main advantage of this approach is the use of a multi-disciplinary approach to identify and quantify the risk and protective factors of arm fractures in the fall of playground equipment.
The application of this method will help to formulate the countermeasure to prevent the related arm fracture in the playground.
Methods and Resultscontrol study (fig 1)
This is the most appropriate design in terms of specificity, effect size, potential deviation, cost and time frame.
According to a review of epidemiology data, the 1 research base is a child under 13 years of age who falls from playground equipment in primary and kindergarten and falls on his arm.
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Control Study design
Cases are defined as children under 13 years of age, resulting in fracture of the upper limb due to falling from school or kindergarten playground equipment.
Long Bone of upper limb fracture (
Represents the largest and most expensive group of playground related injuries.
1, 2 cases including diagnosis corresponding to ICD-10-AM codes S42. 2, S42. 3, S42. 4 (
Fracture of the epiconum), S52 (
Fracture of forearm (including ruler, ruler), and T10 (
Fracture of upper limb, unspecified level).
In the same environment, 17 controllers were children of the same age, who also fell off the playground equipment and fell on their arms, but no broken arms.
Sample size estimation is based on the following assumption: alpha error = 0. 05; beta error = 0. 20 (80% power);
And the odds of \"clinical importance\" are 2. 0.
18 random samples of 176 playground equipment were audited to determine compliance with the currently recommended safety guidelines and to estimate the exposure of children to risk factors of interest (
Height and surface properties of equipment).
The compliance playground is 90%.
Sample size estimates indicate that 533 cases and 533 controls are required.
Five hospitals were selected for case recruitment, accounting for 38% of all playground-related injuries in Victoria.
Approved by the ethics committee for medical records of patients.
Hospital emergency department staff check patient records every week to identify children who meet the eligibility criteria.
Confirmed long backbone fractures of the upper limb were excluded.
The control school was randomly recruited from the catchment area of the participating hospital.
Feasibility determined based on non-annual quantity estimation control
Fracture injury from Ministry of Education data sources.
According to the admission rate of 89% control personnel in the similar study reported, 4 34 schools were required.
Staff at the control school were trained to record playground falls using the standard confidential accident report form.
A definitive scheme was designed to recruit case and control personnel.
After receiving the notification of the case and control measures and the written consent of the parents, an interview with the child was arranged as soon as possible.
The national code of ethics was followed.
20 The Interview agreement developed an interview agreement to determine which devices the child falls from, the height of the fall, and where their arms hit the surface of the playground.
The same protocol was used for case and control interviews.
The children were interviewed at the fall scene in the playground and reported their own fall details.
This improves previous research designs in which parents or other agents complete a questionnaire about a child\'s fall, usually using photos to identify where it falls.
Someone asked 3,6 children: which device did you fall from? ;
What are you doing before you fall? ;
Where are you landing? .
Measure the height of the child and the weight of the clothes, and record the situation of the hand.
The interview questions are designed to be simple and specific.
In order to determine the effectiveness of the child\'s self-report, the child interview response was compared with the adult witness\'s response and the details in the school injury report.
Preliminary results showed that children had good recall and there was no different recall bias between the case and the control.
On-site test protocol Playground Safety Standards 8, 13, 14 were reviewed to develop on-site test protocols with the aim of measuring the physical properties of playground equipment and ground where children fall.
The field measurement results are shown in Table 1.
The depth of the surface material is calculated as the average of the three probe readings 30 cm apart in the triangle around the contact point.
To better describe the surface properties, moisture content (
Dry, residual moisture, wet), age (
Weeks after installation)
And the surface substrate was recorded.
View this table: View inline View pop-up table 1 variable device height measured for each fall event is defined as the vertical distance from the surface to the highest accessible part of the structure.
21 the height of the child\'s fall is the vertical distance between the surface of the playground and the center of gravity of the Child (CoG)
At the beginning of autumn
The CoG table is derived from the child\'s human body measurement data and 22, 23 is suitable for various positions that are often reported at the beginning of a child\'s fall (
Like standing, hanging in your arms). Inter-
The average reliability of the judges measured by the field test between the two testers is 0.
Out of a random sample of 46 playgrounds, 9904.
Development of instruments and meters 5.
4 kg children\'s head meter with three-axis accelerometer (
The standard measures used to determine the safety of the playground are critical deceleration and HIC.
14 field drop tests were conducted from three heights of 1 m, child fall height and maximum equipment height.
The new shock arm load dummyThe head type impact test is limited by its specificity for the risk of head injury.
The playground injury epidemiology review shows that the impact arm load should be quantified in order to specifically investigate the risk factors of arm fracture.
An exhaustive search of existing human body measurement models did not identify a suitable dummy to investigate the risk of a child\'s arm fracture.
Therefore, based on the height and weight data of the proposed sample, a human body measurement dummy capable of measuring the impact arm load (fig 2).
Download figureOpen in the new form download powerpoint figure 2 instrument human body measurement child fall dummy (left)and drop rig (right).
The size and shape of the dummy is based on a 6-year-old surrogate.
The 24 dummy is made of 6mm wide shoulder, 285mm long arm and 420mm steel with 75 × 65mm palm.
The weight of the dummy only is 10 kg, adding a specially manufactured durable board weight to simulate the quality of children up to 50 kg (