Exoskeletons: prevention on the backs of workers

Exoskeletons: prevention on the backs of workers

Put it on like a backpack, then adjust the straps correctly and adjust the pads - it's that easy to put on an exoskeleton and ready for use. There are numerous areas of application in the automotive industry. The prosthesis specialist Ottobock only came across the product through the Volkswagen Group. “VW came to us in 2012 and asked whether we could develop a product to relieve the burden on people with physically demanding tasks such as overhead work and thus create healthier working conditions,” said Hans-Willem van Vliet, Vice President Research & Development at Ottobock, at a product presentation. The result is “Paexo” (see picture), an exoskeleton that can be put on in around 20 seconds and reduces the physical strain on the arm and shoulder muscles when working overhead by around 50 percent. Paexo works according to biomechanical principles, it aligns with people's movements at work and transfers weight to the hips, so that the shoulder joint is relieved.

Such exoskeletons are becoming an increasingly important factor in the automotive industry in the areas of employee protection and prevention of muscular diseases caused by repetitive activities. And the various systems now available on the market open up wide application possibilities in other industries, such as the construction industry.

Common complaints from workers

Musculoskeletal complaints and musculoskeletal disorders (MSD) represent a significant social problem and place a high burden on the healthcare system, the economy and those affected. According to Wifo's 2019 absence report, around a fifth of all days of sick leave are due to illnesses of the musculoskeletal system, with these sick leaves amounting to an average of 15.4 days.

A third of all sickness absences due to MSDs affect employees in the 50 to 64 age group. Combined with the demographic change that Austria is facing - according to Statistics Austria, more than 40 percent of all employees will be over 45 years old in 2050 - MSDs will become an even more serious problem. The use of exoskeletons could help prevent this.

Effective support

“The effectiveness of exoskeletons was evaluated in the EU research project Andy: the physical strain on the test subjects was reduced by 55 percent, and the heart rate during the work also fell by 21 percent,” says Wolfgang Baumann, CEO of AWB Schraubtechnik- und Industriebedarf GmbH, which sells exoskeletons from a wide range of manufacturers. However, there is no need to speak of a panacea; it is a matter of choosing the right product for the right use.

The AUVA also sees it that way; exoskeletons are not (yet) the jack-of-all-trades expected by many employers. “It must be noted that they are not the simple solution to all problems,” say Anne Mück and Markus Lombardini, experts in the ergonomics section of the AUVA Vienna regional office. “Many problems can be solved by making simple design adjustments to the workplace or by changing processes.” Nevertheless, current developments are being monitored very closely and there is potential.

What types of exoskeletons are there?

Basically, three types of exoskeletons can be distinguished: active, passive and soft. "Active exoskeletons contain a motor that carries out the movement for me or supports it very strongly. This is primarily known from rehabilitation," explains Baumann. "The passive ones rely on mechanical aids such as spring or cable systems to support movement sequences and provide relief. Soft versions are more likely to be viewed as supportive or stabilizing." The latter in particular already offer everyday solutions for the construction industry.

Growing repertoire

The currently available repertoire of exoskeletons gives an idea of ​​where things can go in the next few years, and the number of exoskeleton manufacturers is also constantly growing. There are currently around 30 companies that offer and develop products in this segment.

Paexo, the already mentioned product from the prosthesis manufacturer Ottobock, is a passive exoskeleton that does not require any energy supply and is very light at just 1.9 kilograms. When used overhead, the weight of the wearer's raised arms is transferred to the hips via the arm shells using a mechanical cable pull technology. According to the manufacturer, this protects the muscles and joints in the shoulder area.

Noonee develops its products for a different segment. The Chairless Chair, now available in version 2.0, is intended to enable workers to switch smoothly between sitting, standing and walking. This means it can be used primarily for work that requires frequent changes of positions and must be carried out in a very limited, dedicated workspace.

As different as the manufacturers' individual solutions may be, they all have one thing in common: they should only be used after extensive training.

If you use exoskeletons, then do it right

“If you decide to use an exoskeleton, it is essential to train users on how to use and adjust it and to make them aware of the risks,” says Lombardini. Simply handing over the products and letting people try them out doesn't work. In the worst case, this leads to new problems or worsens existing ones. “You have to imagine it a bit like the equipment in a fitness center: if you know how to use them, they help you, if you don’t, they can cause injuries,” adds Mück. Likewise, one should not forget to adapt the workplace and escape routes if necessary, as the exoskeletons partially increase the body surface area.

Baumann also sees it that way, confirming that school enrollment is an essential part of everyday life. “You must not forget that every body is different, and the exoskeleton must be adapted accordingly,” confirms the expert. Practice would show that most workers can do this independently in their everyday work after extensive training. This opinion is also reflected in the findings of a current white paper from the Fraunhofer Institute.

And how much does such an exoskeleton cost?

A hurdle to the widespread use of exoskeletons could be the costs of two thousand to six thousand euros, which are incurred not only for the workplace but for each employee employed there. There is currently no funding – for various reasons.

The three types of exoskeletons

• Aktive Aktive Exoskelette bieten den Anwender eine aktive mechatronische Kraftunterstützung bei einzelnen oder kombinierten physischen Belastungen. Sie weisen eine hohe Komplexität sowie ein höheres Eigengewicht auf, da sie pneumatisch oder von Motoren betrieben werden, eine Stromversorgung benötigen sowie meist modular aufgebaut und erweiterbar sind.
• Passive Passive Exoskelette unterstützen den Träger durch mechanische Hilfsmittel. Auftretende Belastungen werden aufgefangen, infolgedessen werden Bewegungen in der Belastungsrichtung erleichtert. Die Assistenzsysteme kommen ohne den Einsatz von Motoren, Sensorik sowie deren Stromversorgung aus.
• Softe Softe Varianten unterstützen, stabilisieren oder verstärken einen bestimmten Bereich des Körpers und wirken so entlastend.