Studies on Exoskeletons

Content overview:

• Exoskeletons in research and science
• Studies on Paexo Shoulder
  1. „Principle Study on Objective and Subjective Effects of a Passive Exoskeleton“ (Journal IEEE)
  2. Principle study on the effect of an industrial exoskeleton during overhead work (Journal Orthopädie Technik)
  3. Assessing the efficiency of exoskeletons in physical strain reduction by biomechanical simulation with AnyBody Modeling System (Cambridge Univeristy Press)
  4. Exoskeletons in Production and Logistics – Fundamental Principles, Morphology and Implementation Approach (Fraunhofer Austria)
• Studies on Paexo Back
  1. White Paper – The Future of Injury Prevention in Logistics
• Analysis of exoskeletons
• Research on exoskeletons
  1. Institutes conducting research on exoskeletons
  2. Selected scientists conducting research on industrial exoskeletons
• Standards for exoskeletons

Despite automation in industry, recent years have shown that the physical workload for employees in many industries has not decreased. One of the most common work-related diseases is the so-called musculoskeletal disorder (MSD). One of the causes of MSD is overhead work. (see photo)

According to the German Federal Institute for Occupational Safety and Health (BAuA), musculoskeletal disorders result in annual production loss of 17.2 billion Euros in Germany. Nevertheless, the Federal Institute sees great potential for industrial exoskeletons:

A central task is […] the classification and evaluation of now commercially available passive exoskeletons in the working environment. The goal must be to evaluate the practical use of these systems in the workplace. It is necessary to create approaches to identify preventive […] factors and thus enable a reliable evaluation and hence application of exoskeletons in the world of work.

Source: German Federal Institute for Occupational Safety and Health

The Ottobock Shoulder supports employees during strenuous activities in different industries, especially during overhead work. The exoskeleton is the subject of several simulated workplace studies to scientifically prove its effectiveness in reducing MSDs.

In this study, various physical, physiological and psychological parameters of 12 subjects are analyzed and compared while performing overhead tasks with and without the Paexo Shoulder exoskeleton. The assessment criteria used to evaluate the Paexo Shoulder measure both the objective and subjective effects on the users.

The study concludes, as one of its findings, using the Paexo Shoulder exoskeleton significantly reduces anterior deltoid muscle activation by 55%, oxygen consumption by 33%, and heart rate by 19% (objective evaluation criteria). This indicates that the Paexo Shoulder efficiently reduces physical stress and fatigue.

Subjective evaluation criteria included task performance and the potential change in the user’s range of motion while wearing the exoskeleton. The study shows that wearing the Paexo Shoulder feels natural and unrestricted and has neither positive nor negative effects on mere work performance. Overall, the researchers rate the Paexo Shoulder as a promising solution to reduce musculoskeletal disorders in the shoulder.

In this study, the Paexo Shoulder is objectively evaluated using metabolic and electromyographic parameters. Overhead work is simulated under laboratory conditions. The results of the simulation show that the user’s metabolic effort and the load on the shoulder region are significantly reduced. In particular, the deltoid muscle and the biceps brachii muscle show a significant reduction in terms of muscle fatigue when wearing the exoskeleton. The study also shows a reduction in the muscle fatigue value of the trapezius muscle, however, it is significantly lower than for the other two muscle parts.

The study uses computer simulations to evaluate the Paexo Shoulder. The advanced biomechanical simulation software AnyBody technology calculates the impact of biomechanical effects on the human body’s musculoskeletal system when wearing the exoskeleton and without wearing the exoskeleton. This study, in particular, focuses on three biomechanical effects: muscle activity, joint reaction forces in the shoulder and arm area, and compression forces in the lumbar spine area.
The simulation results show that muscle activities and joint reaction forces were significantly reduced when wearing the Paexo Shoulders. For example, activities of the deltoid muscle in the shoulder were reduced by 54%, and forces on the glenohumeral joint (shoulder joint) were reduced by 87%.
The simulation results are then compared with study results from a laboratory experiment in which the Paexo Shoulder was also the research subject. (Results of the laboratory experiment of the study from the journal IEEE – see 1. „Principle Study on Objective and Subjective Effects of a Passive Exoskeleton“]

In the abovementioned whitepaper by Fraunhofer Austria, the Paexo Shoulder exoskeleton is tested by three companies for its suitability in various areas of application. The Paexo Shoulder assists in the execution of various tasks: Ceiling assembly, wall plastering, marking & painting work as well as storage & retrieval activities in a small parts warehouse.
In particular, the Paexo Shoulder receives a very good rating for ease of use: in the statement “I find the exoskeleton, easy to use.” the Paexo Shoulder received an overall rating of 3.60 out of 4.00 highest possible points.

Elevated arm work is prevalent in many jobs. Feasible device-based methods are available to measure elevated arm work. However, we lack knowledge on the association between device-measured elevated arm work and prospective risk of long-term sickness absence (LTSA). We aimed to investigate this association.

Device-measured elevated arm work is associated with increased prospective LTSA. This information ought to be brought into preventive workplace practice by accessible and feasible device-based methods of elevated arm work.

The Ottobock Back supports employees, especially in the logistics sector, during classic picking activities or, for example, when loading and unloading a truck. The Ottobock Back exoskeleton works by relieving the lower back during lifting and carrying activities and is also the subject of research.

The scalefit. method is a way to simulate and analyze the effects of exoskeletons on the human body. The following video shows the analysis of the Ottobock Back during a typical task in logistics, repalletizing. It shows the inclination of the person’s trunk, and compares the resulting compression forces on the lumbar spine in two scenarios: one where the person is wearing the Ottobock Back, and one where they are not.

Institutes conducting research on exoskeletons

Selected scientists conducting research on industrial exoskeletons

• Carisa Harris-Adamson, D., CPE, University of California, Berkley, School of Public Health
• Maury Nussbaum, D., CPE, Virginia Tech, Occupational Safety & Health Research Center
• Leia Sterling, Ph.D., University of Michigan, Center of Ergonomics
• William Marras, D., CPE, Ohio State University, Spine Research Institute
• Denny Yu, Ph.D., Purdue University, Healthcare Ergonomics Analytics Lab
• Prof. Dr. Lars Fritzsche, Dresden University of Technology, Center for Demography and Diversity (CDD)
• Dr. rer. nat. Benjamin Steinhilber, University Hospital Tuebingen, Germany