Background: There has been an unprecedented surge in the popularity of trampolines in the UK and in the number of children attending emergency departments with associated injuries.
Aim: To record the incidence, injury type and risk factors for children attending the emergency department of a busy suburban hospital with trampolining injuries.
Methods: Between May and September 2008, all eligible patients had a proforma completed recording mechanism, time and type of injury, the number of children trampolining at the time of the injury and whether a supervising adult or safety net was present. Analgesia requirements, treatment and follow-up were recorded.
Results: 131 children presented with trampolining injuries (1.5% of paediatric attendances). The average age was 8.8 years (range 1–16). 77 (59%) had no net present and 87 (66%) no supervising adult. 89 (68%) sustained injuries without actually falling from the trampoline and, on average, 2.6 people (range 1–7) were on the trampoline at the time of the injury. 81 (62%) required a radiograph and 40 (31%) were diagnosed with fractures. 18 (14%) required surgery and 28 (21%) were discharged with clinic follow-up. 18 (14%) sustained lacerations that required closure in the department.
Conclusion: The enormous increase in trampoline sales has brought with it a significant increase in the injuries presenting to UK emergency departments. Safety information is given by manufacturers, retailers and local government authorities, but many parents fail to heed this advice. A combination of inadequate adult supervision, several people using a trampoline simultaneously and insufficient safety equipment seems inextricably linked with injury. Greater parental and public awareness is required regarding the potential dangers of what is perhaps unwittingly considered a light-hearted pastime.
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Trampoline sales in the UK have rocketed in the past 10 years with a 600% increase between 1997 and 2002 (C Prentis, Super Tramp Trampolines, Devon, UK, personal communication) and an estimated 50% increase every year since. In 2004 over 120 000 units were sold,1 and trampolines are the third most popular gift among children aged 5–13 years.2 With an estimated 11 500 trampoline-related presentations to UK emergency departments (EDs) in 2002,3 figures for more recent years are assumed to be far higher.
While reports on injury patterns and incidence have come from Scandinavia,4 5 the Republic of Ireland6 7 and North America,8 9 10 there is little recent work from the UK, and that which does exist focuses solely on fractures.1 11
The modern concept of trampolining was developed in 1934 by George Nissen at the University of Iowa. Devised initially for sport and entertainment, trampolines were subsequently used for teaching fighter pilots and astronauts ways of developing a sense of spatial awareness during combat manoeuvres and space flight.12
In the USA the Consumer Product Safety Commission (CPSC) published that almost 100 000 people attended EDs for trampolining injuries in 1999 compared with 37 500 just 7 years earlier.13 Since 1990, 11 deaths related to trampoline use have been recorded.
Noticing the increasing national trend in the purchasing of trampolines for private use, the Local Government Association (LGA)14 and the Royal Society for the Prevention of Accidents3 (RoSPA) have both published guidelines on trampoline safety which, our study suggests, are being summarily ignored by parents and children alike. The Child Accident Prevention Trust15 also advises manufacturers, organisations and members of the public about safety measures that can be introduced to minimise the risk of injury with equipment such as privately owned trampolines.
Kingston-upon-Thames is a suburban, relatively affluent and primarily residential area south west of London. Following a surprisingly large number of trampolining injuries presenting to our busy Children’s ED in the early spring of 2008, we decided to record the incidence and type of injuries that presented during the following summer period.
All paediatric patients attending the ED of Kingston NHS Trust with injuries sustained while trampolining were included in the study. Data were recorded prospectively over a 4-month period (20 May to 20 September 2008), during which time the children’s ED saw 8618 patients aged ⩽16 years. The medical and nursing staff completed detailed proformas which documented patient age, sex, day and time of injury, whether a supervising adult was present and whether the trampoline had safety equipment (netting and/or padding); the number of people on the trampoline at the time of injury; the type of injury sustained, the form of analgesia administered and the treatment subsequently required; whether or not a radiograph was carried out; and the method of patient disposal (admission, discharge home, GP review or fracture/trauma clinic follow-up).
Follow-up telephone calls were made to parents to enquire if their children had continued to use the trampoline once recovered from their injury and whether the parents’ approach to trampolining had changed.
Over the 123 days of the study, 131 patients presented to the ED with injuries sustained while on or falling from privately owned trampolines, which comprised 1.5% of all attendances over that period. Ninety-two (70%) were boys and the average age was 8.8 years (range 1–16, fig 1).
An average of 2.6 people (range 1–7) were on the trampoline at the time of injury and in only 24 cases (18%) was the child the sole person on the apparatus (fig 2).
Twenty-nine children (22%) who presented with acute injuries were aged ⩽5 years and all had sustained their injuries on large trampolines (⩾10 ft diameter). For children aged ⩽5 years there was an average of 2.7 people on the trampoline at the time of injury which, for this age group, is especially hazardous as the lightest person on the trampoline is 5–14 times more likely to be injured.6 13
Fifty-nine injuries (45%) occurred at weekends, although the study period straddled the school summer holidays, increasing the likelihood of weekday injuries occurring. Fifty children (38%) sustained their injuries between 16.00 h and 18.00 h (range 11.00–21.00 h) when the supervising adult was often out of sight preparing food. During this 2-hour period, only 10% of children had a supervising adult present compared with a still meagre 34% for the study as a whole.
The 13–16-year-old age group was least likely to have a supervising adult present regardless of the time of day (11%), while children in the 1–4, 5–8 and 9–12 year age groups had an adult present on average 39% (range 37–41%) of the time (fig 1).
Only 54 children (41%) had safety equipment present at the time of injury (fig 1); however, the presence of safety equipment did not appear to correlate inversely with the likelihood of injury occurring. Children aged 9–12 years were the most likely to present with acute injury (44 cases, 34%) but 43% of this group did have safety equipment present.
Following triage, all but one of the 131 patients received analgesia; 105 (81%) received oral paracetamol or ibuprofen in line with College of Emergency Medicine guidance,16 22 (17%) were given intranasal fentanyl (first-line opiate in our ED for young children) and 3 were given intravenous morphine.
After clinical assessment, 80 children (61%) had a radiograph while one child required a CT scan in line with NICE guidelines for acute head injury.17
All 131 children who presented to the department had a diagnosable injury (fig 3); 89 (68%) were sustained on the trampoline while 42 (32%) were injured after purposely jumping from the trampoline or accidentally falling from it. Of the 42 who fell or jumped from the trampoline, only 2 had a safety net present.
The most common injury sustained was a soft tissue sprain followed by fractures, head injury and laceration (fig 3). Of the 40 children who sustained fractures, in most cases these were in the upper limb (12 wrist/forearm, 10 hand/digit, 8 supracondylar) while the most clinically significant injuries were an open tibial fracture and a comminuted fracture-dislocation of the elbow.
Of the 19 children presenting with acute head injury, 6 arrived by ambulance with spinal immobilisation in place following what were later found to be soft tissue neck sprains.
Eighteen children (14%) required admission for surgical procedures under general anaesthesia (15 orthopaedic, 2 plastics, 1 maxillofacial), 28 (21%) were referred for clinic follow-up (26 fracture clinic, 2 ENT trauma clinic), 6 to their GP and 79 children (60%) were discharged with no further follow-up required.
Through follow-up telephone calls to the parents of 119 children (91%) we were able to ascertain that 115 had continued to use trampolines after or, in some cases, during their recovery phase, but all 119 parents reported that their own attitude to supervision of trampolining and allowing several children on at one time had changed to be more in line with the manufacturers’ advice.
Trampolining injuries are increasing in the UK. How this rate of increase relates to rising sale figures is impossible to say with any degree of certainty as the incidence of injury is not recorded and, with the increasing popularity of internet shopping, accurate UK sales figures are not known.
With falling prices, the trampolines most commonly sold have a relatively short stiff spring and a hard bounce (C Prentis, Super Tramp Trampolines, Devon, UK, personal communication). The majority have fittings for safety nets around the outside of the trampoline frame as opposed to being suspended well inside. This potentially directs the jumper’s body onto the frame and springs where injuries can occur.12
A misguided preconception among parents is that trampoline injuries occur only through jumping off or falling from the frame, so that the presence of safety netting will eradicate risk. We found that 68% of the children sustained their injuries without leaving the confines of the canvas, as was found in previous studies which reported that 60–77% of injuries occurred on the trampoline itself.5 6 7
Those using a net were actually more likely also to have a supervising adult present than children who did not use a safety net (43% vs 27%). This suggests, however, that the supervising adult was less stringent in insisting on other safety measures as they unwittingly felt that the presence of the net would lead to the avoidance of injury.
While older children (aged 13–16 years) are the least likely to use safety netting (19% vs 47% for those aged 1–12 years), they are also less likely to incur injury. This may be due in part to their greater sense of spatial awareness, motor skills and coordination on the trampoline, while younger children also often display a misplaced sense of fearlessness.
Manufacturers, the CPSC and RoSPA all advise that children under the age of 6 years should not be allowed on trampolines over 20 inches in height or of a diameter of >10 feet.3 13 A child weighing 30 kg displacing an average trampoline mat by 60 cm can generate 3 G of force.9 When jumping with several people simultaneously, children aged <6 years—who are both lighter and less likely to have the coordination and motor skills necessary to stabilise themselves—are 5–14 times more likely to be injured than their older friends and siblings.6 13 This potential for increased risk of injury is confirmed in our study. Our patients aged ⩽5 years were more likely to present with a fracture than the study population as a whole (38% vs 31%) and 50% more likely to require surgery for their injury (21% vs 14%).
It is the presence of several people jumping both synchronously and asynchronously on a trampoline that perhaps poses the greatest risk. Synchronous jumping leads to a phenomenon known as “kipping”6 where the combined transfer of potential to kinetic energy imparted by the jumpers causes the lightest person to gain a greater propulsive force and height. This process is used purposefully by coaches to allow competitive athletes to gain more height while practising new routines. For the amateur, however, it simply allows more time for the inherent rotational forces in the jump to cause a misplaced landing, making injury more likely. Asynchronous bouncing will cause less skilled jumpers to be propelled at unplanned angles, again resulting in collisions, misplaced landings and injury. In our study, 107 injuries (82%) occurred with more than one person on the trampoline, which mirrored the findings of other studies (range 51–84%, fig 2).5 6 7 9
The bases of injury are clearly multifactorial. While safety netting certainly stops children falling clean off or jumping dangerously from the frame, unless it is fitted correctly within the area of spring attachment it can potentially push people onto the actual frame structure itself and cause injury.
Children will only benefit from having a supervising adult present if the adult actually instigates safety measures as recommended by manufacturers. Our data show that the adult is often lulled into a false sense of security by the presence of a net and that, when the adult leaves the area or is out of sight of the trampoline, the behaviour of the children changes and more high-risk activity occurs, resulting in peaks of injury at these times.
This inherent love of risk-taking, combined with an as yet poorly developed sense of spatial awareness and gymnastic control, puts children below teenage years at particular risk. Their lighter weight also unwittingly puts them at the mercy of the laws of physics when jumping with larger children.
We would never suggest a ban on what is a healthy sporting activity and, on the whole, a safe and enjoyable pastime. Many tens of thousands of children use trampolines in complete safety every day and none of our patients came from an organised trampolining club. However, the potential for injury is great, especially for those aged <6 years, and the rate is certainly on the increase. At 1.5% of all attendances, the increasing incidence of injury is also now placing a significant burden on the resources of the ambulance services and children’s EDs.
This study has led us to make a number of recommendations. First, we see no reason or logic in selling or advertising a trampoline without a correctly fitted safety net and frame padding included as standard. While the netting and padding will not eradicate all injury, it will certainly reduce it—in the case of our study possibly by as much as 32%.
We recommend that no retailer should release a product until the purchaser has been taken through a safety advice sheet highlighting the potential areas of risk. Likewise, internet-based companies should only send out a product once the purchaser has returned to them by email a brief but completed advice questionnaire downloaded when attempting to purchase a trampoline. If these documents had clearly worded explanations of risk and waivers of responsibility for the manufacturer, it might also heighten the awareness of the purchaser to the risk of injury and alter behaviour patterns.
Finally, emergency physicians are duty bound to educate patients regarding injury prevention. EDs should routinely stock patient/parent advice sheets on the risk elements of trampolining as they do for paediatric head injury and many other conditions.
All the parents questioned in follow-up telephone calls said they had adopted a safer approach to trampolining following their attendance at our department. Unfortunately, for all of them it took an injury to their child to initiate such change.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.
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