Some live with bionic arm or leg prostheses that can even take over complex movement functions. Others wear a wearable exoskeleton every day for rehabilitation purposes or to relieve and support them in their physically demanding everyday working lives. In some jobs, people strain their musculoskeletal system on a daily basis. They carry or stack parcels, suitcases or building materials. They assemble for hours overhead or in a bent-over position. Or in care professions, they help patients with health impairments to cope with everyday life. In such areas, exoskeletons can provide relief, support and prevent damage to health. ABI Research estimates that global sales in this emerging market will exceed USD 7 billion by 2030, with industrial applications being a key catalyst. By 2030, sales of active exoskeletons are expected to exceed USD 5 billion, almost double that of passive devices.

The beginnings of exoskeleton development

Historically, the first experiments with exoskeletons, i.e. external skeletons, originated in the military environment. This is a segment that is primarily driven by state actors and will not be considered further here.

The first market-ready exoskeletons were developed in the rehabilitation environment to help people regain mobility after accidents, strokes or walking disabilities. Portable, supportive rehabilitation exoskeletons are now being developed at a rapid pace. As a rule, they are connected directly to the patient's body and support the legs, spine and torso to correct movement patterns and enable intensive gait training. The aim is to restore motor functions and regain physical autonomy. One of the pioneers in this field is the US company EksoBionic. The 'EksoNR', for example, is a robotic exoskeleton that was specially developed for use in rehabilitation facilities. According to the manufacturer, it is the first exoskeleton to receive FDA approval for the treatment of patients with acquired brain injuries, strokes, multiple sclerosis (MS) and spinal cord injuries.

Exoskeletons for the world of work

The 'Cray X' in use at the Fiege Mega Center Ibbenbüren.

© German Bionic

The market for exoskeletons for the workplace is somewhat younger, but has grown rapidly in the last five years. The focus of research and development here is on occupational safety and health prevention in manual, non-automatable workplaces. This is because almost all sectors and industries in western industrialized countries that rely on manual jobs are currently facing a serious shortage of workers. This is exacerbated by the fact that workers are getting older or are leaving the workforce temporarily or permanently due to injury.

According to the World Health Organization (WHO), musculoskeletal disorders (MSDs) are the main cause of incapacity to work for around 1.71 billion people worldwide. According to the Federal Institute for Occupational Safety and Health (BAuA 2022), MSDs cause an estimated loss of production of EUR 19.6 billion and a loss of gross value added of EUR 32.5 billion in Germany every year. These figures will continue to rise as the population ages.

Prof. Dr. Herbert Schuster, preventive physician and member of the scientific advisory board of the Association of the Exoskeleton Industry (VDEI), explains: "The most important ergonomic risk factors include frequent repetitive activities, high levels of physical exertion and ergonomically unfavorable postures. Exoskeletons are used to avoid these risk factors. In particular, active exoskeletons, i.e. those supported by motors, can reduce muscular strain and energy expenditure during physically demanding activities and thus protect against accidents at work and work-related musculoskeletal injuries."

Exoskeletons in care

The real-time data, which is accessible via the exoskeletons' full connectivity, helps teams and companies with safety management. For example, workers receive individual recommendations via a display while on the job. Here: the 'Apogee'.

© German Bionic

Research and development are still relatively new when it comes to adapting exoskeletons to the specific conditions of care for the elderly and sick - and vice versa. This is because the best possible coordination between man and machine is also essential for patient acceptance in the sensitive area of care. In a recently completed study, the Charité University Hospital in Berlin, in which German Bionic was also involved, investigated how the two areas can be optimally coordinated. The new 'Apogee+' from German Bionic, an active exoskeleton specially developed for care, already has important features and will be presented in June 2023.

Comparison website provides an overview

In the now diverse exoskeleton market, companies are finding it increasingly difficult to make the right choice. The Association of the Exoskeleton Industry (VDEI) has therefore launched the comparison website exo-guide.com, which provides an independent and non-commercial overview of the industry. "In order to find the right system solution for your own company, it is important to take a close look at the respective workplace and application," says Prof. Dr. Herbert Schuster. "What effect do you want to achieve? What do you need for the specific application? Are there specific framework conditions in the working environment? How flexible should the exoskeletons be?"

Passive or active exoskeleton?

The German Bionic IO provides up-to-date information on every shift: with data on exoskeleton operating hours, weight compensation, lifting processes and steps. The user-defined dashboards make it easy to identify risk factors in workflows, new occupational safety measures and their added value.

© German Bionic

An important distinction is between purely mechanical or passive exoskeletons and robotic or active exoskeletons. This involves the type of energy source, which also has an influence on the possible applications.

Passive or mechanical exoskeletons redirect the required force via cable pulls, springs or dampers. Load compensation is therefore a zero-sum game in the energy balance. Due to their fairly simple mechanical operation, they are lighter and, as there are now a relatively large number of suppliers - including from China - they are inexpensive to purchase. Passive exoskeletons are particularly suitable for static tasks such as overhead work.

Active or robotic exoskeletons, on the other hand, combine mechanical structures with battery-powered electric motors and are controlled by software and sensors. They were developed in interactive research specifically for repetitive lifting and carrying activities with heavy loads that put a lot of strain on the lower back. They add additional energy to the worker's physical strength, thereby actively contributing to sustained work without the risk of overload, avoiding peak loads and preventing errors or even injuries caused by fatigue. In addition to occupational safety, this also improves the work result.

The initially somewhat bulky models have now given way to lighter and more comfortable models. This means they can also be used flexibly in dynamic working environments. Active exoskeletons provide support in logistics and intralogistics, when fitting tires, handling luggage at the airport or delivering parcels. Dustproof and waterproof models also provide support on construction sites. "To explain how an active exoskeleton works, I like to draw a comparison between a bicycle and an e-bike," explains Prof. Dr. Herbert Schuster: "As with an e-bike, when using active exoskeletons, power is added to your own muscle strength in a flexibly adjustable way."

Exoskeletons for flexible applications

Most exoskeletons are technically focused on relieving the strain on certain local muscle groups - the shoulders when working overhead or the lower back when lifting and carrying. All-rounders with support for several body regions, on the other hand, are in demand in flexible and dynamic workplaces that involve repetitive lifting and carrying activities as well as long walking distances or, if necessary, prolonged work in a bent-over position.

Over-head shoulder exoskeletons relieve strain on the back and neck, for example in the automotive industry when working on the bodywork. The mostly passive systems use regenerative forces to transfer the load to more robust areas of the body such as the hips. They fix and support the arms and shoulders over a longer period of time. They were among the first exoskeletons to be widely accepted in production worldwide. In 2020, Toyota Motor North America was the first company to introduce exoskeletons as mandatory personal protective equipment (PPE). An innovative example of a passive exoskeleton is the 'Mate-XT' from Comau, which consists of a sweat- and dust-repellent fabric and provides support, particularly for overhead work, for example in assembly, construction or agriculture.

Exoskeletons for the lower back relieve local muscle groups in the lumbar vertebrae area to provide protection during repetitive lifting and carrying activities. One example of a passive wearable chest and back support that adapts to different postures is the 'Laevo'. Relief is provided by a gas pressure spring: when bending the back or squatting down, it is preloaded and the energy is released again when straightening up.

Extra power through hybrid automation

The 'Cray X' and 'Apogee' exoskeletons from German Bionic are examples of active models that provide support when lifting, carrying and working in a bent-over position for long periods of time. The sensor and software-controlled devices adapt automatically to all body types and working environments. They actively support up to 30 kg per lifting operation and are also networked, allowing real-time data to be recorded and analyzed. This real-time ergonomics data enables greater safety in the workplace. An additional self-learning AI component provides individual recommendations and identifies optimization potential in work processes.

Overall, this is a hybrid automation approach: where automation reaches its limits, smart wearables and robotic exoskeletons provide ergonomic relief for physically hard-working people and at the same time integrate them into digital processes in an AI-based, connected and safe manner.

The author: As Head of Global Communications, Eric Eitel is responsible for public relations at German Bionic.

© German Bionic

Last but not least, exoskeletons generate effects of inclusion beyond their pure functionality by opening up the labor market to social groups that traditionally feel excluded in certain occupational fields. According to forecasts, human augmentation will continue to progress - and exoskeletons will become an integral part of our lives.