In recent years it would be difficult to find another health related issue that has received more media attention than Traumatic Brain Injuries (TBIs). Put simply a TBI occurs when an external force acts on the skull and the transfer of that force cause a significant injury to the brain. TBIs are a leading cause of death and permanent disability in children and young adults. As the leading international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services; ASTM has a responsibility to ensure that the standards it sets are in line with the most accurate and current data possible. The current standard for the measurement of impact attenuation on playground safety surface systems is based on outdated data and, in light of more recent research, is woefully lacking in its ability to safeguard children using these playgrounds. The intent here is not to criticize the current standard. The 1292 standard was developed with the data available at the time and as such is as good as it could have been. Since the standards original inception, science has moved forward and so must the standard. As a point of reference the following question should cause some concern. In which situation would a child be safer; an 8-foot fall to a playground surface with corresponding F1292 HIC score of 1000 or an offset frontal crash in a 2007 Toyota Camry traveling at 40 MPH? A bit of a trick question; the car crash is probably safer. In order for a car to receive a Good IIHS rating in a 40MPH frontal offset crash the HIC score cannot exceed 560; a poor rating must be below 840 HIC (http://www.iihs.org/iihs/ratings/ratings-info/frontal-crash-tests). Shouldnt we, as an organization, strive to be better than poor? As should be obvious, an AIS of less than 4 should be the target if the intent is to minimize TBIs in children. The question is then how do we relate an AIS4 to a HIC score. There is a distinct correlation between HIC scores and AIS: as the HIC value increases so does the likelihood of an injury occurring which has a correlated AIS value of 4+. As the HIC reaches approximately 1000, the chance of an injury with an AIS of 4+ occurring is 20%. As a point of reference from the table above, an AIS of 4+ has roughly an 8-10% chance of causing death. Using a real life scenario, assume its a nice sunny day and a group of children are at a local playground. Further assume the playground surface system has a lab tested HIC value of 1000. Putting these numbers together would give you the following theoretical outcome: A child falling on his/her head has a 20% chance of incurring an injury with an AIS of 4+ An injury with an AIS of 4+ has an 8-10% chance of resulting in death A child falling on his/her head has a 2% cumulative chance of death Using existing research and data the HIC value in the ASTM F1292 standard should be lowered from 1000 to 700. This is based on the current NHTSA standard for dummies used in car crash simulations. The key thing to consider is that the value should maximize the chance of any head injury occurring would have an AIS of less than 4. At that level the chance for death drops from over 10% to just under 2%. This is significant especially if you calculate the cumulative chance of injury relative to the impact attenuating properties of a given surface. ASTM as an organization has the responsibility to ensure the accuracy of its standards. The technical accuracy of the current F1292 standard is not in question. The test works as it is designed to work. The inaccuracy comes from a false underlying premise that a maximum HIC score of 1,000 accurately measures a playground safety surfaces ability to minimize TBIs in children. The science on this issue has come a long way since this standard was originally developed. It is the absolute duty as a standards organization for ASTM and its voting members to revise the current standard to be more in line with current knowledge and research. Moving the upper HIC limit from 1,000 to 700 will accomplish this from a purely technical perspective. From a more humanistic perspective it will also serve to minimize the risk to countless children and young adults of suffering a TBI from a fall at a playground. To do anything less is an abdication of responsibility by ASTM in general and F08 specifically.
Keywordscritical fall height; head impact; head injury criterion; HIC; impact; impact attenuation; impact test; injury; play; playground; play structure; shock; surface; Impact testing--sports applications/equipment; Instrumental measurement; Playground equipment--specifications; Sports equipment--specifications; Sports facilities playing surfaces--specifications; Velocity; Attenuation; Comparison techniques; Consumer safety specifications (playgrounds); Digitizers; Free fall test method; Head form velocity;