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Work, health, military: is the augmented human revolution already here?

How to assist or augment workers

Marina Julienne, Independent Journalist
On June 23rd, 2022 |
3 mins reading time
How to assist or augment workers
Jean-Jacques Atain Kouadio
Jean-Jacques Atain Kouadio
Assistance expert at the Ergonomics and Psychology Applied to Prevention (EPAP) laboratory at INRS
Key takeaways
  • Musculoskeletal disorders (MSDs) account for 88% of occupational illnesses in France and back pain accounts for 20% of work-related accidents.
  • In 2012, the INRS launched an initial prospective study entitled “Use of physical assistance robots by 2030 in France” to relieve workers.
  • For the shoulder, for example, the teams viewed the inter-bone and tendon spaces, using ultrasound, and compared the behaviour of this joint with and without assistance.
  • But exoskeletons are not an answer to all the physical constraints to which employees are exposed.

How long has INRS been interested in this subject?

In 2012, INRS launched an ini­tial prospec­tive study enti­tled “Use of phys­i­cal assis­tance robots by 2030 in France”. At the time, there were two exoskele­tons in France that were being test­ed in com­pa­nies. Bare­ly ten years lat­er, there are some forty of them avail­able on the mar­ket! They range from pos­ture har­ness­es that help relieve the back to robot­ic exoskele­tons that com­pen­sate for effort. For us, it is excit­ing that research and inter­ven­tions in the field are in phase with the emer­gence of these phys­i­cal assis­tance technologies.

Why are companies using exoskeletons?

Mus­cu­loskele­tal dis­or­ders (MSDs) account for 87% of occu­pa­tion­al ill­ness­es and back pain accounts for 20% of work-relat­ed acci­dents – a size­able num­ber! As well as the dam­age caused to employ­ees, MSDs have a high eco­nom­ic cost for com­pa­nies and social secu­ri­ty (days off work). This is why mechan­i­cal devices that help com­pen­sate for the phys­i­cal efforts of oper­a­tors or assist them in their move­ments are already employed or being stud­ied in all fields: from the auto­mo­tive to the nuclear indus­try, includ­ing con­struc­tion, mass retail­ing, the health-med­ical-social sec­tor, etc.

How do you study these devices?

The lab­o­ra­to­ry stud­ies focus on han­dling and hold­ing loads to observe the con­se­quences on the activ­i­ty of the mus­cles that are assist­ed as well as those that aren’t, on pos­ture and on motor coor­di­na­tion. For the shoul­der, for exam­ple, our team has stud­ied the space between bone and between ten­don tis­sue using ultra­sound and com­pared the behav­iour of joints with and with­out exoskele­tal assis­tance. We are also car­ry­ing out assis­tance in con­junc­tion with pre­ven­tion net­works in com­pa­nies to analyse how exoskele­tons are inte­grat­ed and whether or not they are being accept­ed by employ­ees. It is impor­tant to under­stand that the dif­fer­ence between this tech­nol­o­gy and “clas­sic” phys­i­cal assis­tance is that it is attached to the per­son­’s body. This assis­tance, while help­ing to reduce effort, can, at the same time, be felt by the wear­er as a phys­i­cal and psy­cho­log­i­cal restraint. 

Do these devices effectively relieve physical effort?

Exoskele­tons can bring sig­nif­i­cant ben­e­fits, but they offer very localised assis­tance and do not address all the phys­i­cal con­straints to which employ­ees are exposed. Impor­tant­ly, they can them­selves cre­ate new bio­me­chan­i­cal con­straints: impact on the mus­cu­lar activ­i­ty of mus­cles not assist­ed by the exoskele­ton, impact on bal­ance, on motor coor­di­na­tion, suit­abil­i­ty for high rates of work and high degrees of move­ment repet­i­tive­ness, trans­fer of bio­me­chan­i­cal demands to oth­er parts of the body, etc. The nature and extent of the ben­e­fits or lim­i­ta­tions observed depend on the activ­i­ty per­formed (the work­ing pos­ture adopt­ed, load han­dled, work rhythm, etc.), the tech­ni­cal char­ac­ter­is­tics of the exoskele­ton (con­tact points, weight, stiff­ness, etc.), and the tasks identified.

So, it’s not that simple for companies to adopt these exoskeletons?

They must think very care­ful­ly before choos­ing equip­ment and con­sid­er the impact it will have on the whole work organ­i­sa­tion. We are pub­lish­ing guides to help them ask the right ques­tions. First, think­ing about pos­si­bly mak­ing use of an exoskele­ton must be accom­pa­nied by a broad­er reflec­tion aimed at reduc­ing the con­straints linked to phys­i­cal activ­i­ty through organ­i­sa­tion­al changes, train­ing, etc. The pre­cise nature of the phys­i­cal assis­tance required must then be defined (the body areas to be assist­ed, pos­tures usu­al­ly adopt­ed, load weights han­dled, etc.)

If the exoskele­ton solu­tion is cho­sen, it is then cru­cial to ini­ti­ate a test process by address­ing pre­cise eval­u­a­tion cri­te­ria: to what extent has the oper­a­tor tak­en on the equip­ment? Is it easy to use? Is it real­ly use­ful? What are the effects of using the exoskele­ton on the envi­ron­ment and the work group? How many peo­ple in a team will be equipped with an exoskele­ton? How will oth­ers view those who wear it? The exoskele­ton must be includ­ed in work­sta­tion analy­sis risks, as it may, for exam­ple, lead to new col­li­sion risks for the per­son wear­ing the equipment.

Many com­pa­nies do not realise the extent to which exoskele­tons can dis­rupt an entire work­ing environment.

What are the regulations on the subject?

We must remem­ber that exoskele­tons are there to “assist” oper­a­tors and not to “enhance”. To put it plain­ly, in the future, oper­a­tors will not be car­ry­ing loads that they were not car­ry­ing before, but rather car­ry­ing loads that they were already car­ry­ing with less risk of impact on their health. In this respect, the stan­dards in force today con­cern­ing load and phys­i­cal stress lim­its for man­u­al han­dling tasks must con­tin­ue to be respected.

Exopush: a textbook case

In 2014, the com­pa­ny Colas1 exper­i­ment­ed with its first robot­ic exoskele­ton, “Exo­push”, for road­works where work­ers had to spread and lev­el asphalt on the road. A kind of robot­ic rake was devel­oped. It con­sist­ed of a har­ness, a strut that trans­fers the weight of the load to the ground in order to reduce effort and improve the user’s pos­ture and a tele­scop­ic han­dle that detects the user’s inten­tion and extends his move­ment. This equip­ment was lit­tle used in the field, how­ev­er. A mul­ti-dis­ci­pli­nary steer­ing com­mit­tee bring­ing togeth­er the com­pa­ny’s inter­nal and exter­nal pre­ven­tion play­ers was then set up, with the par­tic­i­pa­tion of the INRS. Numer­ous meet­ings with the teams were organ­ised, the equip­ment was adapt­ed, the work­ers were trained, and a ded­i­cat­ed deploy­ment man­ag­er was appoint­ed in 2019 to gen­er­alise the use of almost 90 Exo­push­es in the dif­fer­ent branch­es of Colas.

1INRS; deploy­ment of a robot­ic exoskele­ton, feed­back from the Colas com­pa­ny. Sept 2021