Helmets with a perfect fit
Better fit and more wearing comfort for head protection for work and leisure
BÖNNIGHEIM (vo) Motorcyclists do it. Construction workers do it. And the rule for more and more skiers and snowboarders is: Not without my helmet! While it used to be mainly small children and safety fanatics who used ski helmets, many winter sports enthusiasts are now aware that a helmet can offer protection in case of a fall or crash. But not every helmet is right for everyone. And how could it? Not all heads are the same: It is a known fact that shape and circumference can differ greatly from person to person. Helmet manufacturers know this, too, but they have to work with the measurement information currently available for helmets.
This is where a research project (AiF no. 16976 N) at the Hohenstein Institute in Bönnigheim which started in summer 2012 comes in: The scientists want to use the project with an expected duration of two years to create the data basis for optimised textile based head protection systems. ‘Even the safest of helmets cannot offer optimum fit and protection if it is not right for the individual head size and shape of the wearer,’ says Simone Morlock who manages the project at the Hohenstein Institute. The research results will enable manufacturers to offer consumers helmets with a better fit in the future.
The results can be transferred to all head protection systems – and there are many of them today, for work and leisure: The models range from the construction trade, police and military to helmets for cyclists, skaters, riders or water sports enthusiasts. On so-called personal protection equipment, for example for firefighters, face, ear and respiratory protection also play a very important role. According to the German compulsory accident insurance there were almost 79,000 notifiable work accidents with head injuries in 2011 alone. The head is the third most common area of injury. However, as head protection systems are only worn consistently if they are comfortable, ideal fit is very important.
Despite the great demand for suitable head protection systems there are no well-founded anthropometric head data of women, men and children available in Germany to date. Firstly, the known standards which are applied to head protection systems do not contain the required measurement information for deriving 3D shapes. Secondly, the measurements in the standards are not the current state of the art. The German Commission for Occupational Health and Safety and Standardization (KAN), which unites all relevant institutions for occupational health and safety in Germany, expressly recommends comparing the ten year old anthropometric data of the standards to current data.
Other countries have progressed much further with the implementation of projects for optimised head protection systems. Anthropometric data collected in other countries, e.g. in China or the USA, cannot be applied to Germans, though, as different ethnic groups show basic differences in their body and head morphologies, due to genetics.
The researchers at the Hohenstein Institute are using their representative pool of raw scan data from male and female test subjects of all age groups as a basis for defining characteristic 3D head morphologies, creating average head shapes and soundly deriving all relevant parameters for the development of corresponding protection systems. ‘For the first time, we are determining the distribution of actual head shapes and not just of head circumferences to be representative for the German population,’ explains project manager Simone Morlock.
In addition to the known head measurements from the ergonomics standard, the scientists at the Hohenstein Institute will be taking additional measurements and evaluate these to derive characteristic head morphologies. In addition to head shape, the project will also research facial measurements and provide dimensional descriptions, meaning possible dimensional correlations between the eye, nose, mouth and ear areas. The categorising of these morphologies into representative head shapes for men, women and children will be an important step. In the end, interested manufacturers will have access to specific sizing systems describing the current head and face dimensions to be used as a basis for the design of head protection systems. There will also be standardised, realistic virtual average 3D head shapes.
In addition to fit-specific criteria, physiological aspects of moisture wicking have a substantial influence on wearing comfort. The materials used influence the climatic conditions inside a helmet. It is therefore important to optimise the textile interiors of helmets with regard to clothing physiology and hygiene. Ski helmets for example are meant to protect against the cold as well as ensure moisture wicking. The hygienic properties in turn have been completely disregarded until now, even though they play an important role, for example for rental helmets. Increased sweating inside the head protection generates a warm and humid climate which diminishes wearing comfort while also creating ideal conditions for the growth of microorganisms. This results in unwanted odours and can trigger the development of scalp infections.