Unprecedented experiment to integrate exoskeletons on construction sites

Inspired by the TMS Pros system deployed by Carsat, the approach combines field observations, ergonomic diagnostics and experiments in real situations to identify the conditions for a reasoned integration of Physical Assistance Devices (PAD). The key: a better understanding of the needs of workers and concrete lessons to adapt equipment to the realities of construction sites.

Better integration of exoskeletons in construction

Many companies are now tempted to acquire Physical Assistance Devices (PADs), particularly exoskeletons, to compensate for the efforts of operators. While initial experimental studies tend to demonstrate that exoskeletons can be effective in limiting certain local muscular constraints, their use in real work situations nevertheless raises many questions: adaptability to tasks, impact on posture, physiological constraints on other parts of the body, and acceptability by operators. This results in difficulties with appropriation, discomfort during use, or rapid abandonment of the equipment, due to a lack of real adaptation to job gestures or support for change.

Also, to ensure that the exoskeleton is suitable for the operator and the task for which it is intended, it is necessary to rely on an approach ranging from defining the need for physical assistance to its integration in a real situation. In this approach, the role of ergonomists, occupational physicians and prevention officers is decisive, particularly in exploring collective prevention levers upstream before resorting to individual equipment.

It is precisely in this logic of support as close as possible to the field that the joint work carried out by the FFB Nouvelle-Aquitaine and Carsat Aquitaine, in partnership with the OPPBTP, is part of. The objective is to support craftsmen and construction company managers as well as their employees, with a view to improving working conditions and advancing the prevention of occupational risks by offering them solutions adapted to their needs.

A field diagnosis based on real needs

The first stage of the experiment consisted of three independent ergonomics firms (Ergolibri, LMVT Conseil and NC Ergonomie) carrying out a detailed diagnosis of the work situations of four volunteer companies. In each case, the ergonomists observed actual gestures, postures, work rates and site constraints, based on representative construction sites.

• C2B, a carpenter and roofer based in Tarnos (40), was observed during metal structure assembly activities in the workshop and on site.
• Lamecol, a carpenter based in Canéjan (33), was studied in three workshops: the assembly and gluing of wooden parts (glulam), the finishing and assembly of wooden frame structures (OSB)
• SCA - Société de charpente Agenaise, based in Boé (47), was the subject of observations in the workshop and on site more specifically for the activity of laying tiles.
• De Laborie, a company specializing in painting and coating based in Pau (64), was analyzed across three trades: painters, floorers and exterior thermal insulation installers.

These observations highlighted the most disadvantageous situations in terms of carrying loads, working with arms in the air, prolonged maintenance in awkward postures, or repetitive movements. They also revealed that certain constraints could sometimes be reduced in ways other than the use of exoskeletons, for example through organizational adjustments or existing equipment. Finally, they showed that certain constraints could be mitigated in ways other than the use of exoskeletons, in particular through organizational adjustments, the use or acquisition of suitable equipment, or by sharing experience between employees.

Each company was then supported to develop specifications outlining its physical assistance needs, and then to select and test different devices in real-life conditions, on its own construction sites or in workshops. This experimental phase made it possible to observe actual uses and identify the benefits, as well as the obstacles, associated with each type of exoskeleton tested. Ultimately, each company was able to make a reasoned and informed choice: maintaining, adjusting, or abandoning certain devices, but also implementing additional actions to reorganize work or raise awareness among teams.

An experiment rich in lessons

Beyond the use of the equipment itself, the experiment highlighted the crucial importance of support from ergonomists, enabling companies to better understand the challenges of MSDs, to carefully analyze their real needs, and to avoid impulsive or poorly targeted purchases.

This approach also made it possible to identify that certain work situations, particularly heavy handling phases on uneven terrain, remain difficult to reconcile with current exoskeletons. This observation opens up avenues for improvement for manufacturers and raises the question of adapting operating methods more broadly.

To enable other construction structures to engage in a similar dynamic, two tools will be released shortly:

• A practical self-assessment questionnaire to help companies ask themselves the right questions before embarking on an exoskeleton integration project.
• A methodological guide, detailing step by step the approach to the reasoned integration of physical assistance devices, in line with the NF X 35-800 standard.

For Virginie Larroudé, engineer specializing in ergonomics: “The exoskeleton is not a simple purchase; it is an approach guided by ergonomics. In collaboration with the Peinture De Laborie teams, a detailed analysis of three priority work situations was conducted, highlighting the physical constraints encountered on various construction sites. This study made it possible to establish precise specifications for suppliers and to optimize the time allocated by employees to demonstrations and testing of exoskeletons outside of workstations. Three models were thus selected and tested directly on site, specifically for two tasks: painting ceilings and installing floor coverings.”

For Nathalie Coulon-Yvars, ergonomist (NC Ergonomics): “An exoskeleton is not adopted, it is accompanied. Beyond the choice of equipment, it is the support for its integration that really determines success. Three stages proved essential: first, a presentation of the different exoskeletons to allow employees to discover them, handle them and demystify this still little-known tool; then a simulated test, in a close-to-real but secure environment, for example by creating a portion of a frame in a workshop; finally, if the test proves conclusive, a field trial, as close as possible to real-life activity. This progressive approach builds confidence, reduces the risk of rejection and guarantees appropriate and sustainable implementation.”

Furthermore, Marie Tonel, ergonomist (Ergolibri firm) notes, through her field observations at Lamécol, that in certain phases of hyper-dynamic activity requiring full-body engagement, the tested exoskeletons were too restrictive. At the gluing stations (glulam), the work rhythms are very sustained and paced by finger-jointing; operators felt hampered in the fluidity of their movements, especially since the height constraints are severe at these stations. She adds that at the timber frame assembly stations, it was rather the versatility of the tasks that led to the abandonment of exoskeleton tests because no model met the need. Indeed, these findings allow us to glimpse new avenues of improvement for manufacturers, in terms of design and materials to improve the comfort of exoskeletons. They also highlight the importance of activity analysis in ergonomics to gain a more global understanding of physical characteristics, characteristics of the work environment and those of the organization.

However, for very specific and penalizing tasks (repetitive gestures, arms in front of the person while standing for prolonged periods), the on-site evaluations have proved positive, and the company is about to finalize the purchase of the exoskeleton.

"My support allowed Lamécol to target the exoskeleton adapted to the specific operating methods for sanding and varnishing tasks. By drawing up the specifications, I was able to identify the areas of the body that needed relief. For this, observations and discussions with the two operators involved were essential. In the end, out of six exoskeleton models tested in three workshops, only one was selected for two operators on the panel, which puts the notion of large-scale "deployment" of DAPs into perspective," notes the ergonomist.

Finally, the specificity of the experiment at Lamécol is the central role given to the occupational physician-ergonomist duo. "As part of the experiment, the occupational physician was involved in the project very early on, even before carrying out the exoskeleton tests. It was essential to ensure that the volunteers involved in this process were in "good health" and without any fitness restrictions. We made this choice with the occupational physician to neutralize the risk of methodological bias in the evaluation of the system. Also, because we considered that we were in a logic of primary prevention and not of maintaining employment, which is a different type of support."

Illustrative image of the article via Depositphotos.com.