Are exoskeletons a viable option for protecting construction workers?

Construction work is still undeniably manually intensive in most parts of the world. Consequently, it is common for workers to be exposed to risk factors such as manual materials handling work, working under harsh environmental elements, highly repetitive work, and the need to constantly work under pressure to meet targets. Manually demanding construction operations are associated with musculoskeletal disorders, injuries, and premature retirement from the workforce due to an inability to continue working (Gutierrez et al., 2024). Construction organisations also suffer related consequences including reduced efficiency, high absenteeism, poor quality, high compensation costs, and high turnover

While different technological advancements have been introduced to the construction sector, manually demanding work continues to pose risks to workers and organisations in the short and long term and will continue to thwart productivity and health and safety goals if they are not curbed. Organisations often cite costs and an inability to redesign construction work systems as a hurdle in making significant advances to minimise manual work. Given the current challenges that inhibit organisations from significantly minimising exposure by re-designing construction work, it is important to explore alternative options that can minimise exposure to manual labour risks and make workers more “resilient” to such exposure. One such technological solution is exoskeletons.

What are exoskeletons?

The term exoskeleton is usually associated with the rigid external protective covering found in some insects and invertebrates. The exoskeleton in these insects and invertebrates is designed to protect their bodies from external harm (Figure 1A). Exoskeletons in the insect/animal world may have inspired the development of an emerging technology known as exoskeletons (Figure 1B). The term exoskeleton is now also known to refer to a variety of devices that are worn by humans to increase their physical capabilities (e.g. strength capacity) and minimise the impact of external physical loading (Kim et al., 2019). Other terms that are used for exoskeletons include wearable robot, exosuit, or supersuit (Zhu et al., 2021).

Figure 1A Exoskeleton

Figure 1B Exoskeleton

How do exoskeletons work?

The objective of exoskeletons is two-fold. On the one hand, exoskeletons are designed to enhance the human’s physical performance by augmenting the capacity of the musculoskeletal system in terms of strength, speed, and agility (Zhu et al., 2021). Another objective of exoskeletons is to act as a buffer that absorbs some of the energy and forces that are created when a human interacts with various objects around them (e.g. forces on the back when lifting a box, or exposure to vibration while carrying a load).

To realise these physical gains, exoskeletons are worn outside the body and are aligned to various upper and lower body segments (e.g. arms, hands, legs, trunk). It is fitted with numerous sensors and other technologies that gauge speed and direction of movement, forces, postural loading, and speed. The exoskeleton is meant to become part of, or an extension of, the body and is meant to provide the necessary biomechanical support to the body (Zhu et al., 2021). It does so by counteracting or absorbing excessive loading on various segments of the body or fortifying whatever movement or forces are produced by the wearer, thus reducing exposure to risk factors that are associated with musculoskeletal injuries and disorders. There are two main variations of exoskeletons, active and passive exoskeletons. Active exoskeletons have electric, hydraulic or pneumatic actuators that increase physical capabilities (e.g. strength) while passive exoskeletons are designed to redirect and store energy and biomechanical strain in springs or dampers (Gonsalves et al., 2024).

Are exoskeletons effective?

Exoskeletons are still regarded as an emerging technology. While advancements have been made, much remains unknown about how to design exoskeletons that become a true extension of the body and enhance performance without inadvertently causing harm. Research on the most optimal designs and tests of the most effective prototype for occupational settings continues. Variations of exoskeletons have also been made available commercially. However, there are still design and implementation challenges that exoskeleton designers and manufacturers are grappling with to improve their efficacy (Weston et al., 2018). Some of these challenges, which certainly are applicable to construction workplaces, include the following:

• Ensuring that the exoskeleton does not impose unnecessary biomechanical and physiological loading on the wearer which could exacerbate over-exertion injuries and disorders.
• Ensuring that the exoskeleton is easy to wear and take off and that the wearer can do so himself, especially in case of emergencies.
• Ensuring that the exoskeleton is comfortable in all postures and during all activities that must be executed.
• Ensuring that the exoskeletons effectively consider human variability and are designed to fit humans of all shapes, sizes, ages, medical status, and gender without compromising physiological and biomechanical loading as well as comfort.
• Ensuring that the exoskeleton is lightweight, not bulky, and does not unintentionally interfere with other objects in the working environment or prevent the wearer from accessing work areas easily.
• Ensuring that exoskeletons are cost-effective, accessible, and easy to maintain for different organisations.

Is the South African construction industry ready for the widespread deployment of exoskeletons?

Construction is an age-old profession that, despite many process and technological advances, is characterised by the same suboptimal working conditions it did ages ago. To solve some of these persistent challenges, designing construction work systems to minimise the strain experienced by workers is paramount. In the absence of construction work system reform, exoskeletons offer a potentially different solution that focuses on augmenting worker capabilities in the face of manually intensive construction work demands. These wearable devices have already started being tested and some are deployed in various industries including the military as well as manufacturing and logistics industries. While promising results have been reported for some exoskeletons, much work remains to be done to improve their efficacy. Moreover, various implementation challenges would need to be addressed.

There are still many unanswered questions regarding how to effectively implement exoskeletons in our context. Unfortunately, very little research on exoskeletons is being carried out for the South African construction industry. It would be valuable if more research on exoskeletons could be done in the South African construction context so that some of our unique requirements can be considered and accounted for in the design of exoskeletons. While we are not yet at a place where all construction workers can be issued exoskeletons, they are certainly an innovative solution that should be explored by all progressive South African construction organisations that want to invest in improving worker health and safety while also advancing productivity goals.

Sma Ngcamu-Tukulula (CPE)

Smart Ergonomics

References

Gutierrez N., Ojelade A., Sunwook Kim S., Barr A., Akanmu A., Nussbaum M., and Harris-Adamson C. (2024). Perceived benefits, barriers, perceptions, and readiness to use exoskeletons in the construction industry: Differences by demographic characteristics.

Gonsalves N., Akanmu A., Shojaei A, and Agee P. (2024). Factors influencing the adoption of passive exoskeletons in the construction industry: Industry perspectives. International Journal of Industrial Ergonomics, 100, 103549.

Sunwook Kim, Albert Moore, Divya Srinivasan, Abiola Akanmu, Alan Barr, Carisa Harris-Adamson, David M. Rempel & Maury A. Nussbaum (2019): Potential of Exoskeleton Technologies to Enhance Safety, Health, and Performance in Construction: Industry Perspectives and Future Research Directions, IISE Transactions on Occupational Ergonomics and Human Factors.

Weston, E. B., Alizadeh, M., Knapik, G. G., Wang, X., & Marras, W. S. (2018). Biomechanical evaluation of exoskeleton use on loading of the lumbar spine. Applied Ergonomics, 68, 101–108.

Zhu, Z., Dutta, A., & Dai, F. (2021). Exoskeletons for manual material handling – A review and implication for construction applications. Automation in Construction, 122, 103493.

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