Ski/snowboard helmets
Discussion
Copying this post from the Schumacher thread for others to reference.
With the recent injury to Michael Schumacher I did a bit of digging around the safety standards of our ski/snowboard helmets.
In short it seems for Europe the helmets should pass CEN/EN 1077 but what isn't clear is that there are two classes. A and B with A offering the superior protection.
The inside of your helmet should tell you what type you have might be worth you looking at yours. Personally I thought both of my helmets offered far greater protection than they do.
Class B
Must protect the top and rear of the head but doesn't have to cover the ears
Must be able to withstand an impact from a drop height equivalent to 375mm (37.5cm)
Class A
Must protect the top and rear of the head and also the ears/side of the head
Must be able to withstand an impact from a drop height equivalent to 750mm (75cm)
Shocking for me that class B only has to withstand impact from 37.5cm. Falling on to my arse is a bigger drop than that?! Perhaps something good to come out of Schumacher's accident is a review and possible improvement of helmet standards. I cannot see that 37.5cm is sufficient.
Further it appears from my reading that CE/CEN standards do not test for impact with trees or rocks.
With the recent injury to Michael Schumacher I did a bit of digging around the safety standards of our ski/snowboard helmets.
In short it seems for Europe the helmets should pass CEN/EN 1077 but what isn't clear is that there are two classes. A and B with A offering the superior protection.
The inside of your helmet should tell you what type you have might be worth you looking at yours. Personally I thought both of my helmets offered far greater protection than they do.
Class B
Must protect the top and rear of the head but doesn't have to cover the ears
Must be able to withstand an impact from a drop height equivalent to 375mm (37.5cm)
Class A
Must protect the top and rear of the head and also the ears/side of the head
Must be able to withstand an impact from a drop height equivalent to 750mm (75cm)
Shocking for me that class B only has to withstand impact from 37.5cm. Falling on to my arse is a bigger drop than that?! Perhaps something good to come out of Schumacher's accident is a review and possible improvement of helmet standards. I cannot see that 37.5cm is sufficient.
Further it appears from my reading that CE/CEN standards do not test for impact with trees or rocks.
Thanks - good info on the MIPS system. List of MIPS helmets available here.
http://mipshelmet.com/find-a-helmet
Reading up on MIPS and the existing standard I really do find myself asking if the current ski/snowboard certification is fit for purpose. It seems blinding obvious that the vast majority of falls will be angled and not perfectly vertical as tested in the current standard.
http://mipshelmet.com/find-a-helmet
Reading up on MIPS and the existing standard I really do find myself asking if the current ski/snowboard certification is fit for purpose. It seems blinding obvious that the vast majority of falls will be angled and not perfectly vertical as tested in the current standard.
Bit more clarity for those interested. At 15mph your head is subject to around 220g on impact. Ski/snowboard helmets test to 250g. So I'm reading that as if you're travelling faster than 15-20mph you ski/snowboard helmet is not fit for purpose.
Sobering and I'm stopping reading as I'm off skiing next week!
http://www.satrappeguide.com/EN1077.php
EN 1077: 2007
Ski helmets
Shock Absorption
Where helmets are intended to provide protection for the users’ head in the case where the user themselves provide the movement, or where the user is likely to come under impact from items other than from above, helmets are usually tested using the falling headform method. Instead of using a fixed headform impacted with a falling mass, the headform itself, with the helmet fitted, is raised above a fixed anvil and dropped to generate the impact. Headforms, which are typically made from aluminium alloy, are made in several sizes so as to allow a reasonable fit to the helmet, and contain a tri-axial accelerometer (three single accelerometers in the x, y and z planes). On impact, these accelerometers will record the acceleration (or in this case, deceleration) of the headform in all three directions, and record a resultant value. In addition, the acceleration plotted over time can be used to calculate the head injury criterion (HIC), which gives a measure of the expected likelihood of serious injury to the user. It is calculated based on an integration of the acceleration against time between two points on in time.
Helmets can be dropped onto different types of anvil, including flat, kerbstone (corner) and specific-shaped anvils, such as balls. Drop heights will vary from each standard, depending on the perceived hazards in use. In the case of ski helmets, the headform is dropped from a height of approximately 1.5 m (up to 89 J) onto a flat anvil, with a maximum allowable acceleration of 250 g (2453 m/s2). Testing is carried out following conditioning to high temperature, low temperature or UV ageing.
Penetration
Ski helmets are tested to ensure they offer sufficient protection against sharp or pointed objects. The test is based on a method similar to the fixed-headform shock absorption test, in that a striker is dropped from a set height onto the helmet fitted to a fixed headform. However, in this case, the striker is a pointed cone (of mass 3 kg, dropped from a height of 0.75 or 0.37 metres, depending on the class of the helmet), and rather than measure the transmitted force, the assessment is based on whether the striker makes contact with the test block underneath the helmet. This is typically carried out using indicator material (e.g. plasticine or soft metal) on the test block itself. As with the impact testing, this is carried out on helmets pre-conditioned to high temperature, low temperature, or UV ageing.
Design Requirements
Most specifications for protective helmets include a number of requirements for the design of a helmet in addition to the specific performance requirements. These typically encompass the area of coverage provided by the helmet, as well as the field of vision afforded to the user when worn. They can also cover a number of ergonomics and safety-based requirements, such as clearance between the head and the shell of the helmet (particularly in the case of industrial helmets).
Retention System
Helmets can only protect the head when they are being worn and therefore the means for retaining the helmet on the user's head requires as much attention as the rest of the head protection, and so is subject to a series of tests. The specific test carried out is dependent on the type of helmet, but two main tests are carried out:
Retention system strength: The retention system (in particular, the chin strap) is subjected to a force, applied either statically or dynamically, to ensure the strap is unlikely to fail at the point where it is most necessary. In the case of industrial helmets, it is however desirable that the chin strap will not cause a strangulation hazard, and so cannot be too strong, and therefore straps need to include a break-away element at the anchorages, intended to fail within a specific load range. Typically, the helmet, including chin strap, is fitted to a suitably-sized headform, with the chin strap either fitted to an artificial chin (consisting of two rollers mounted on a frame), where the headform remains static, or to the chin of the headform itself, where the headform is used to dynamically apply the force. The chin strap is then subjected to either a static force (where the artificial chin is slowly loaded until failure) or a dynamic (shock) load, applied using a falling mass, and the amount of stretch in the chin strap is measured.
Retention system effectiveness: Helmets are subjected to a shock load, applied to the rear or front of the helmet in an attempt to pull the helmet off the headform. This is intended to consider the risk of the helmet catching on an obstacle and being unintentionally pulled off the user's head. The test load (applied using a 10 kg falling mass) is applied, via a system of pulleys, to the rear of the helmet when mounted on a suitable headform, with the direction of loading following a direction approximately 45° from the horizontal towards the front of the headform (this is occasionally repeated on the front of the helmet). In order to meet the requirements of most protective helmet standards, the helmet must remain on the headform.
Sobering and I'm stopping reading as I'm off skiing next week!
http://www.satrappeguide.com/EN1077.php
EN 1077: 2007
Ski helmets
Shock Absorption
Where helmets are intended to provide protection for the users’ head in the case where the user themselves provide the movement, or where the user is likely to come under impact from items other than from above, helmets are usually tested using the falling headform method. Instead of using a fixed headform impacted with a falling mass, the headform itself, with the helmet fitted, is raised above a fixed anvil and dropped to generate the impact. Headforms, which are typically made from aluminium alloy, are made in several sizes so as to allow a reasonable fit to the helmet, and contain a tri-axial accelerometer (three single accelerometers in the x, y and z planes). On impact, these accelerometers will record the acceleration (or in this case, deceleration) of the headform in all three directions, and record a resultant value. In addition, the acceleration plotted over time can be used to calculate the head injury criterion (HIC), which gives a measure of the expected likelihood of serious injury to the user. It is calculated based on an integration of the acceleration against time between two points on in time.
Helmets can be dropped onto different types of anvil, including flat, kerbstone (corner) and specific-shaped anvils, such as balls. Drop heights will vary from each standard, depending on the perceived hazards in use. In the case of ski helmets, the headform is dropped from a height of approximately 1.5 m (up to 89 J) onto a flat anvil, with a maximum allowable acceleration of 250 g (2453 m/s2). Testing is carried out following conditioning to high temperature, low temperature or UV ageing.
Penetration
Ski helmets are tested to ensure they offer sufficient protection against sharp or pointed objects. The test is based on a method similar to the fixed-headform shock absorption test, in that a striker is dropped from a set height onto the helmet fitted to a fixed headform. However, in this case, the striker is a pointed cone (of mass 3 kg, dropped from a height of 0.75 or 0.37 metres, depending on the class of the helmet), and rather than measure the transmitted force, the assessment is based on whether the striker makes contact with the test block underneath the helmet. This is typically carried out using indicator material (e.g. plasticine or soft metal) on the test block itself. As with the impact testing, this is carried out on helmets pre-conditioned to high temperature, low temperature, or UV ageing.
Design Requirements
Most specifications for protective helmets include a number of requirements for the design of a helmet in addition to the specific performance requirements. These typically encompass the area of coverage provided by the helmet, as well as the field of vision afforded to the user when worn. They can also cover a number of ergonomics and safety-based requirements, such as clearance between the head and the shell of the helmet (particularly in the case of industrial helmets).
Retention System
Helmets can only protect the head when they are being worn and therefore the means for retaining the helmet on the user's head requires as much attention as the rest of the head protection, and so is subject to a series of tests. The specific test carried out is dependent on the type of helmet, but two main tests are carried out:
Retention system strength: The retention system (in particular, the chin strap) is subjected to a force, applied either statically or dynamically, to ensure the strap is unlikely to fail at the point where it is most necessary. In the case of industrial helmets, it is however desirable that the chin strap will not cause a strangulation hazard, and so cannot be too strong, and therefore straps need to include a break-away element at the anchorages, intended to fail within a specific load range. Typically, the helmet, including chin strap, is fitted to a suitably-sized headform, with the chin strap either fitted to an artificial chin (consisting of two rollers mounted on a frame), where the headform remains static, or to the chin of the headform itself, where the headform is used to dynamically apply the force. The chin strap is then subjected to either a static force (where the artificial chin is slowly loaded until failure) or a dynamic (shock) load, applied using a falling mass, and the amount of stretch in the chin strap is measured.
Retention system effectiveness: Helmets are subjected to a shock load, applied to the rear or front of the helmet in an attempt to pull the helmet off the headform. This is intended to consider the risk of the helmet catching on an obstacle and being unintentionally pulled off the user's head. The test load (applied using a 10 kg falling mass) is applied, via a system of pulleys, to the rear of the helmet when mounted on a suitable headform, with the direction of loading following a direction approximately 45° from the horizontal towards the front of the headform (this is occasionally repeated on the front of the helmet). In order to meet the requirements of most protective helmet standards, the helmet must remain on the headform.
fandango_c said:
What surface is assumed for 220g? As the link is to an article on bike helmets, it may not be entirely relevant for skiing/boarding.
Why is a a helmet not fit-for-purpose if you're travelling over 15-20mph? They provide protection to the head from some impacts. The level at which a helmet is tested at is not the point at which it no longer offers protection.
The link to bike helmets stated that at 15mph the head will be subject to a force of 220g. The laws of physics don't change because you are doing a different sport hence I believe still relevant to skiing and snowboarding.Why is a a helmet not fit-for-purpose if you're travelling over 15-20mph? They provide protection to the head from some impacts. The level at which a helmet is tested at is not the point at which it no longer offers protection.
Why do I consider a helmet not fit for purpose at 15-20mph? Because your average skier or snowboarder will be regularly breaching those speeds within a few days on the slopes.
My view is that the upper limit of the existing certification for ski/snowboard helmets is at the lower end of the speeds most skiers/snowboards travel at.
The vast majority of people on the slopes are travelling at speeds beyond which the current helmets offer protection and therefore they are not fit for purpose.
What has surprised me in looking into this is it appears the certification bodies are well aware of this and noted by the reference above ASTM document from 2005 which found in a study
"The average speed for all observations was 43.0 km/h (26.7 mph)".
"The observed speeds are well above the speeds (22.6 km/h, or 14.0 mph) used for ASTM F 2040 helmet testing protocols for recreational snow sports helmets."
ASTM 2040 is the US comparable standard for European CE/EN 1077.
March 2008
http://www.rit.edu/news/utilities/pdf/2008/2008_03...
Dr. Jasper Shealy, a professor from Rochester Institute of Technology who has been studying skiing and snowboarding injuries for more than 30 years.
“The reality is there is a limited amount of protection a helmet can provide,” Shealy said. ASTM International, a standards development organization, says that helmets provide protection at speeds up to 12 to 13 mph. Shealy said those standards are arbitrary but that “27 mph is the speed at which people die,” which is well above the standard.
Page 165 Section 5
http://books.google.co.uk/books?id=nV6lRYaUfTEC&am...
Does this make any difference to me skiing or the way I ski? No because I don't consider myself a skier that puts myself in danger. Those days are long past. Will I still wear my helmet? Yes.
But if nothing else this little bit of research has made me understand what kind of protection a ski helmet offers and I've been surprised to realise it's a lot less than I thought. A lot less.
Edited by Agent Orange on Monday 13th January 11:35
fandango_c said:
They offer some protection, but like most safety devices, they have limitation. I suspect that to make the effective at speeds you mention above would result in the helmet being to big/heavy to use. I would also be concerned by lack of protection to my internal organs in my torso which a helmet doesn't protect.
Absolutely and you are possibly correct about the size of the helmet. But until I looked into this I didn't realise the minimum requirement for a ski helmet to pass certification was comparatively low compared to the impact forces a skier and boarder are more likely to receive.If a person spends 90% of their time doing an activity where the protective gear they are wearing is only really affect 10% of the time you might consider the gear to be not fit for purpose.
Personally I'm looking to change my EN1077 Class B helmet and am instead looking to replace with an EN1077 Class A with ideally MIPS.
Just noticed Gary Hartstein, (@formerf1_doc), pushing for changes in ski helmet design.
Key comment for me
"Ski helmets, on the other hand, are designed and homologated (WHEN they’re homologated) almost solely to prevent skull fractures. While this provides an easy method of evaluation in testing labs, we know that this has VERY little (if anything) to do with the actual mechanisms of brain injury."
Key comment for me
"Ski helmets, on the other hand, are designed and homologated (WHEN they’re homologated) almost solely to prevent skull fractures. While this provides an easy method of evaluation in testing labs, we know that this has VERY little (if anything) to do with the actual mechanisms of brain injury."
Gary Hartstein said:
Now, the FIA Institute has done remarkable applied research in helmet design, and the helmet Felipe was wearing reflects that research. This helmet was designed specifically with very demanding requirements for impacts with objects having rounded edges as well as those having sharp edges, and equally for penetration resistance. These requirements were based on known mechanisms of injury in the sport concerned, and the levels of energy seen.
Ski helmets, on the other hand, are designed and homologated (WHEN they’re homologated) almost solely to prevent skull fractures. While this provides an easy method of evaluation in testing labs, we know that this has VERY little (if anything) to do with the actual mechanisms of brain injury. And unfortunately, Michael is a living demonstration of this.
Therefore, I’d like to throw a few ideas out there:
the Federations responsible for skiing, from recreational to competitive, should convene a working group of experts to look at the epidemiology of head injury in the sport
conclusions should be drawn about the kind of head protection likely to mitigate the injuries ACTUALLY SEEN
Jean Todt should offer the full resources of the FIA Institute (data, expertise, etc) to help design this helmet, to make it affordable, and to make sure it is used as widely as possible.
Michael’s injury is no more tragic than those of every patient who suffers severe head trauma. If, however, his public persona spurs action that goes on to significantly improve the safety of skiing, it will be another of his many remarkable accomplishments!
http://formerf1doc.wordpress.com/2014/01/24/some-f...
Ski helmets, on the other hand, are designed and homologated (WHEN they’re homologated) almost solely to prevent skull fractures. While this provides an easy method of evaluation in testing labs, we know that this has VERY little (if anything) to do with the actual mechanisms of brain injury. And unfortunately, Michael is a living demonstration of this.
Therefore, I’d like to throw a few ideas out there:
the Federations responsible for skiing, from recreational to competitive, should convene a working group of experts to look at the epidemiology of head injury in the sport
conclusions should be drawn about the kind of head protection likely to mitigate the injuries ACTUALLY SEEN
Jean Todt should offer the full resources of the FIA Institute (data, expertise, etc) to help design this helmet, to make it affordable, and to make sure it is used as widely as possible.
Michael’s injury is no more tragic than those of every patient who suffers severe head trauma. If, however, his public persona spurs action that goes on to significantly improve the safety of skiing, it will be another of his many remarkable accomplishments!
http://formerf1doc.wordpress.com/2014/01/24/some-f...
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