2. Measuring spine compression (is hard)

A lot of research has been performed on the effects of wearing an exoskeleton on the human body. Because Laevo has been pioneering commercially available exoskeletons since 2013, there has always been great interest in Laevo exoskeletons from research groups worldwide. These two independent studies show Laevo's leading presence in published exoskeleton literature: De Bock, 2022 and Ashta, 2023.

Spine Compression Force Sensor

Almost all exoskeleton research starts with comparing muscle activity with and without exoskeleton. This is good, as it shows how effective an exoskeleton is at preventing muscular disorders. But what about the skeletal disorders? Yes, as we learned, there is a strong relation between back muscle activity and spine compression. But can we measure spine compression force directly? Well yes, technically we can, but it requires placing pressure sensors inside the intervertebral disc, which looks something like the image below.

As you can imagine, there will not be many volunteers for a study like this.

On the other hand, measuring muscle activity is becoming easier and easier, both in terms of the availability and ease of use of EMG equipment. However, Laevo has seen many wrong conclusions drawn from EMG exoskeleton research. More about this in chapter X on this page.

Musculoskeletal Modeling

Another methodology that is being used more and more is Musculoskeletal Modeling. Using motion sensors on a subject’s body, the motion of the subject’s skeleton and muscles is digitally recreated. Combining this data with simultaneously measured muscle activity data allows the researcher to calculate many skeletal forces including spine compression. Like with all digital modeling and simulation of real-life scenarios, many assumptions have to be made while setting up such a study. But at least it is can provide us with plausible spine compression forces, without placing invasive sensor devices in the subject’s spine.

Why measure or calculate spine compression force in exoskeleton research?

There is not much research published on the effects of exoskeleton on spine compression, simply because it is so hard to measure and therefore draw definitive conclusions on. Laevo would like more researchers to step into this topic, as it is not muscular disorders but primarily skeletal disorders that lead to long-term absence or people becoming unfit for work for the rest of their lives.

But Laevo believes this is only half of the story. Which of these exoskeletons is able to reduce spine compression and prevent long-term absence?

There is no scientific evidence that we know of yet, but if you look at the basic forces exerted on the body by different types of exoskeletons, Laevo, and many well-respected researchers and scientists around the world agree that: