Industrial Standards & Regulations

New Scientific Study on the Effectiveness of the HAPO Passive Back-Support Exoskeleton

The French ergonomics company ErgoSanté has released a free-to-access scientific article on the effects of its HAPO back-assist passive exoskeleton. The research was conducted by an internal division within the company. Participants were recruited from company employees not associated with exoskeleton projects.

erector spinae longissimus muscle Canva 2023
erector spinae

The full paper is titled “Effects of a passive back assistance exoskeleton for load carrying and trunk bending tasks” and is penned by T. ALBOUYa, K. LEBELa, B. LE TELLIERa, all three of whom are ErgoSanté employees. The data is based on EMG, force platform, and motion capture measurements, as well as a questionnaire. The results are based on the 14 participants, eight men, and six women. The participants were recorded performing two sets of tasks. The first was lifting a load of 6 kg from the ground placed 20 cm in front of the participant to a platform. The second task was to maintain a posture for one minute with the legs straight but bending forward at 40 degrees.

external oblique
external oblique

The study demonstrated that the HAPO version 2022 passive exoskeleton is capable of reducing the muscle activation of the erector spinae longissimus. In addition, participants reported a reduction in perceived discomfort. In return for using the exoskeleton, there was no significant drawback, with the exception of increased muscle activation of the external oblique. The authors conclude that the wearable device has the potential to reduce the onset of low back pain at work.

The full paper is free to access and can be located on the HAPO product page on the company website under the “Laboratory Study” category: link.

Q&A with one of the Authors, Dr. LE TELLIER:

Dr. Bérenger LE TELLIER, Scientific Manager at ErgoSanté, was kind enough to answer some questions regarding the study.

Q: Could you comment on the measured increase in external oblique muscle activity?

A: Our study have shown a significant difference in external oblique muscular activity only for the load lifting task. In particular, the increase of EMG signal has been observed during the first phase of the movement (going down) in which subjects have to “force” against the spring of the Hapo. The benefit of the Hapo is felt during the second phase (going up) on back muscles thanks to the energy stored in springs. By the way, external oblique muscle results must be qualified since the muscular activation was relatively low in both conditions (11% and 14% of the Maximal Voluntary Contraction, respectively without and with the exo).

Q: Could you comment on the study being conducted internally within ErgoSanté?

attaching an Xsens Sensor ErgoSante
Attaching an Xsens motion capture sensor, courtesy of ErgoSanté

A. Scientific evaluations are part of our R&D process: our exoskeletons are developed under an iterative approach: POC > prototype > evaluation > prototype > evaluation > …. > final product > evaluation. I guess we are the only exo manufacturer following an iterative approach. Each prototype is evaluated regarding technical criteria (evaluation against technical specifications), usability (criteria relative to the end-user: weight, time for donning-doffing…), and biomechanical criteria (we have our own lab with EMG sensors, IMU, and force platform + subjective questionnaire). This approach gives us objectivity (our evaluations are based on figures) and reactivity (we don’t have to wait having the final product to have an idea of the impact of the exo on people). The present paper shows the results of the new version of the Hapo with objectivity and transparence. Not only the lab is completely independent of the R&D team, but also the subjects who have participated to the study are workers not involved in exo development. Anyway, objective results cannot be influenced by the choice of subjects, either they are part of the company or not.. 


It is encouraging to see that the HAPO exoskeleton performed well under testing. The ExR team can only imagine one day having standardized testing that can demonstrate exoskeleton safety and/or performance.

Stay tuned for more news from ErgoSanté as the company is planning a set of announcements and reveals at the upcoming WearRAcon 23.

Featured image (top) ErgoHealth Technology courtesy of the ErgoSanté Photo Library.

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