Laevo V2 – Support2019-02-20T14:25:35+01:00

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FAQ’s

My Laevo slips down2017-03-09T15:07:16+01:00

V2.2

Probably your suspenders are not fastened properly. It is possible the Laevo slips down a little bit sometimes. Try to avoid this by fastening the suspenders securely, if necessary with safety pins.

V2.3

Tighten the belt a bit more, or try to shorten the suspenders.

What are the anatomical structures in my back and how do they work?2017-05-22T14:02:07+01:00

The most important part of a human’s back is the spine. The spine attaches the skull to the pelvis and consists of 24 individual segments: the vertebrae. There are nine more vertebrae which form two fused bony structures: the sacrum and the tail bone. Each vertebra has structures were muscles are attached. These muscles are important for the movement of the spine.

Figure 1. A part of the spine seen obliquely from behind with the spinal processes and the transverse processes marked, these are the places where the muscles are attached.

The spine has two important functions: one is to carry the body weight and the second is to protect the spinal cord and all the nerves emerging from the spinal cord. The bony processes (the vertebral body and the vertebral arch) of the vertebrae join together to form a canal within which the spinal cord is located and protected.

Figure 2. The spine, lateral view, anterior view and posterior view respectively.


The articulating vertebrae are named according to their region of the spine, the cervical, thoracic and the lumbar spine. The cervical spine is built out of seven vertebrae (curving forward), the thoracic spine out of twelve vertebrae (hollow shaped) and the lumbar spine consists of five vertebrae (curving forward). The S-like shape of the vertebral column is important for stability.

Above and below each vertebra are joints called facet joints. These joints restrict the range of movement in the vertebral column. Each vertebra is attached to another by an intervertebral disc. These discs are formed by a gel-like centre (nucleus pulposus) surrounded by fibrocartilage tissue (annulus fibrosus). The soft tissue of the nucleus pulposus makes the intervertebral disc an ideal shock absorber.

Furthermore, numerous ligaments can be found in the human’s back which attribute to stability, as well as muscles and tendons.[i].

Figure 3. Most important muscles of the back

Spine enables six different movements
Because of the anatomy of the back, only limited movement is possible:[i].

Figure 4 a, b & c. 

a: Ante flexion and retro flexion (figure 4a)

b: Lateral flexion (figure 4b)

c: Rotation (figure 4c)

Sources:

[i] Slowik, G. (2012). Understanding how the back works. Geraadpleegd op 28-10-2014 van http://ehealthmd.com/content/understanding-how-back-works

[i] Standring, S., Ellis, H., Healy, J. C., Jhonson, D., Williams, A., & Collins, P. (2005). Gray’s anatomy: the anatomical basis of clinical practice. American Journal of Neuroradiology, 26(10), 2703.

I feel continuous pressure whilst wearing the Laevo2017-02-06T21:48:32+01:00

Standing in an upright position, there should be some space between your chest and the torso plate. You should contact Laevo when you feel the pressure high on the chest; probably your Laevo does not fit properly.

Does the Laevo weaken my back muscles?2017-05-22T14:02:07+01:00

No, the Laevo supports the back muscles: it takes over 40% of the muscle activity, your own back muscles produce the other 60%. The exoskeleton helps to avoid overload in the extensor muscles of the back and therefore reduces lower back injuries, it does not support the muscles responsible for trunk stability. The function of all the back muscles stay perfectly normal!

Does the Laevo allow sitting?2017-02-06T21:45:16+01:00

We do not recommend sitting whilst wearing the Laevo, because the torso plate gives pressure on the chest. However, we are working on a solution…

Is it possible to carry more whilst wearing the Laevo?2017-02-06T21:43:58+01:00

Yes and no. Probably you are wearing the Laevo because you have physical complaints because of your work. Carrying more and heavier loads will only make your complaints worse.
However, when we look at the working mechanism of the Laevo on the pressure in the spine, the maximum lifting weight may be increased from 23 kg to 31 kg, according to the NIOSH-equation.

 

Where does the name Laevo come from?2017-05-22T14:02:07+01:00

The word Laevo (pronounced: Levo) is derived from the Latin verb levare, which means “to lift”, “to raise”. The perfect word for the product!

How can I be sure my Laevo has been adjusted properly?2017-05-22T14:02:08+01:00

Please follow the following bullet points carefully to check whether your Laevo has been adjusted properly:

  • The centre of rotation of the smart joint is placed correctly in respect to the centre of rotation of the hip
  • The centres of rotation of both smart joints are in line with each other
  • The torso plate rests on the centre of the sternum (breast bone)
  • The leg pads are placed at one third of the upper leg
  • The hip pad is tightened and the Laevo feels comfortable around the hips
  • The hip belt is tightened like a normal belt
  • The suspenders are tightened and the Laevo maintains in the same position with respect to the body

Not sure you followed the checklist correctly? Please have a look at our QuickGuide or contact us.

The torso plate tilts and stings my chest2017-05-22T14:02:08+01:00

Sometimes it is possible the Laevo tilts and stings. Please contact Laevo when your Laevo does so.

Is the Laevo suitable for any type of work?2017-05-22T14:02:08+01:00

No. You should not wear the Laevo when you:

  • Have to switch from standing to sitting positions often
  • Work on high altitudes
  • Have to climb or walk stairs often
  • Work in tight environments

Not sure if the Laevo is suitable for your type of work? Please do not hesitate to contact us.

What is the weight of the Laevo?2017-05-22T14:02:08+01:00

The Laevo exoskeleton weighs 2,3 kilograms (i.e. 5,07 lbs).

Is it possible to wear the Laevo underneath my clothes?2017-05-22T14:02:09+01:00

Yes this is possible, but we advise you not to wear it directly on your skin. Wearing the Laevo underneath an overall, vest or jacket should not be a problem when the exoskeleton has enough space for movement. Caution with necklaces etcetera.

Is it possible to adjust the level of support of my Laevo?2017-05-22T14:02:09+01:00

Unfortunately, this version does not allow for adjusting the level of support. Please contact Laevo if the level of support does not fit your expectations.

What is the functional life-time of my Laevo?2017-05-22T14:02:09+01:00

The springs of the Laevo have a life-time of 250.000 bows. This number is presented on the inside of the smart joint. Please contact Laevo when you have reached the number of 250.000 bows.

How many people are using Laevo’s exoskeleton?2017-05-22T14:02:09+01:00

At the moment over 250 people are using the exoskeleton, testing and research is done in even more people. The Laevo is being used for both prevention and cure of lower back pain.

The leg pads of my Laevo are sliding away2017-05-22T14:02:09+01:00

If this is happening, the adjustments of your Laevo are not quite right. Move the smart joint further forwards along the hip belt. In this tutorial we show you how it is done. Still no success? Please contact us for help.

While bending forward, the torso plate hits my throat2017-05-22T14:02:10+01:00

Probably the Laevo has not been fit to your body shape properly. To overcome this problem, please follow the next steps:

  • Place the smart joints further down by giving the suspenders more length
  • Move the smart joints further backward over the belt

Inthis tutorial we show you how it is done. Still no success? Please contact us for help.

What is an exoskeleton?2017-05-22T14:02:10+01:00

An exoskeleton is an external skeleton that supports the human body. There are a few applications of exoskeletons, such as: rehabilitation, prevention and gain of function. Laevo’s exoskeleton primarily targets on prevention and cure of lower back injuries, it is a passive exoskeleton, which means there are no batteries or motors implemented to make the Laevo work.

Should I wear the Laevo the whole day immediately?2017-05-22T14:02:10+01:00

In order to get used to the Laevo, we advise to wear the exoskeleton only one hour on the first day. Two hours on the second day, four hours on the third day and finally eight hours on the fourth day. Please note that this is an advice; it is possible that it takes a little longer to feel comfortable with it.

Do I need to service my Laevo?2017-05-22T14:02:10+01:00

The Laevo is a low-maintenance exoskeleton and does not need special regular maintenance. We advise you to clean the Laevo once in a while and store it correctly. Laevo’s exoskeleton is not protected for outdoor and/or dusty circumstances; the product will work, but it might damage the Laevo in an earlier stage. In order to protect the Laevo against damage caused by dust and other particles, Laevo developed a protective sleeve. We recommend to let the springs replaced after having bent the Laevo for 250.000 times.

Is there a possibility I will cling to objects whilst wearing the Laevo?2017-05-22T14:02:10+01:00

So far, no incidents were reported on clinging to tables, cables and other objects whilst wearing the Laevo; however, there is a possibility this could happen. In order to reduce the risks of clinging we advise you to wear the Laevo underneath your work clothes.

Could anybody use my Laevo exoskeleton?2017-05-22T14:02:11+01:00

Yes, that is possible. Basically there are two ways of using the Laevo:
1. Custom made: most of the time we custom fit the Laevo to a person’s needs. In this case you should preferably only wear your own Laevo, because it has been custom made for you. Of course, people with the same body shape can wear it too.
2. Standard size: wearing a non-custom made Laevo works as well, but it might have some influence on the comfort. Please make sure to adjust the Laevo to your body shape for the best comfort.

What proof is there of Laevo’s effectiveness?2017-05-22T14:02:16+01:00
[This research was conducted with the Laevo V1.0]

Laevo effectiveness determined

In the spring of 2014, TNO conducted independent research on the Laevo, in collaboration with the VU University Amsterdam (results not yet published). The 18 test subjects had an average age of 25 years. An assembly task, often used in the industry and where one works in a bent-over position of 40⁰, was simulated in the lab. In addition the test subjects also did a task while in a static posture. They were tested on how long they could cope doing the task without feeling too much discomfort in the lower back. Both tasks were performed twice: once with the Laevo and once without the Laevo.

What did they measure?

The effectiveness of the Laevo was measured on two levels: one was an objective measurement of muscle activity and the other was a subjective measurement based on discomfort and the determination of how long they could cope.

They measured the muscle activity (the exertion level) of two major lower back muscles (the Erector Spinae Iliocostalis and Erector Spinae Longissimus) with Electromyography (EMG). This was done in order to determine the effect of the Laevo on the lower back. In addition, they also measured the muscular activity of the hamstrings and the straight and oblique abdominal muscles. This was done to find out whether the Laevo had moved the exertion from the back to the legs or the abdomen.

The effect of the Laevo was measured subjectively, using a validated method developed by TNO, called the Lokaal Ervaren Ongemak score (locally experienced discomfort). This method indicates the discomfort experienced by the test subject in different regions of his/her body on a scale from 0 (no suffering) to 10 (almost maximum). The purpose of this method is to determine whether the effects of the Laevo, according to the EMG, are similar to what the test subjects experienced (subjectively). In addition, it was possible to determine how long they could cope doing a certain task and compare these measurements between the two conditions (with and without Laevo).

Altijd bij vermelden Eigendom van TNO (2)

Photo owned by TNO

Results: 40% reduction in muscle activity and an increase of coping time by a factor of 3

The muscle activity in a bent-over position of 40 degrees experienced an average decrease of 40% when wearing the Laevo, compared to when not wearing the Laevo. In addition, no increase in muscle activity in the hamstrings or abdominal muscles was found. As a result of the second task (task done in a static posture) on the basis of the discomfort score, the subjects could do the task three times as long when wearing the Laevo. This task had a clear resemblance between muscle activity and occurred discomfort: both were strongly reduced. No difference in the degree of discomfort was found for the assembly task, which did not correspond to the considerable decrease in muscle activity that was found. This can be explained by the duration of the task, which was too short to cause discomfort in the lower back.

Conclusion

On the basis of these results it can be concluded that the Laevo reduces the pressure on the lower back muscles compared to when the Laevo is not being worn. In addition, the Laevo makes it possible to do work in a bent-over position three times as long before critical discomfort occurs, or to do the same type of work with less discomfort. The researchers concluded that the Laevo is an interesting and promising tool in reducing the (lower) back pressure when doing high-frequency work in bent-over positions.

How can we interpret the effect of Laevo in respect to NIOSH?2017-05-22T14:02:16+01:00

There are many ways to calculate the effects of a measure on the exposure to physical strain. Within the Risk Inventory and Evaluation (RI&E) an organization may introduce and substantiate a method themselves or use expert opinions. In practice, the NIOSH method is the method used by the Ministry of Social Affairs and Employment and by most other organizations to calculate the physical pressure on the back.

The NIOSH is a scientifically validated method to assess whether certain work situations where the worker is required to lift something/someone should be considered risky. By using a formula it is possible to calculate what weight the worker is allowed to lift in a certain situation, without incurring a health risk. This weight is also called the Recommended Weight Limit (RWL) and depends on a number of factors:

– Horizontal distance from the load to the ankles (Hf);
– Vertical distance from the load to the ankles (Vf);
– Vertical moving distance of the load(Df);
– Trunk rotation/asymmetric factor (Af);
– Frequency of lifting something (Ff);
– Contact with the load (Cf).
The matching NIOSH equation is as follows: RWL = 23kg * Hf * Vf * Df * Af * Ff * Cf

An example of a calculation module for the NIOSH: http://www.arbobondgenoten.nl/arbothem/lichblst/lifttest.htm

In the most ideal work situation the RWL is 23 kilograms. In other cases, the recommended weight will be less than 23kg. When the actual weight lifted exceeds the RWL, the worker faces a risk of health hazards. This risk can be calculated by using the lifting index: dividing the actual weight lifted by the recommended weight (RWL). When the lifting index is greater than 1, the risk of complaints of pain in the bones, muscles and joints (also referred to as the musculoskeletal system) will increase

[1].

The Ministry of Social Affairs and Employment uses the lifting index as follows:

Lifting index LI According to NIOSH According tfo Ministry
0 to 1 Ok Green
1 tot 2 Too heavy Orange  > within employer’s responsibility
2 and higher Too heavy Red > not allowed

 

The NIOSH and the Laevo

It is proven that the muscle activity of the lower back muscles and the strain on the spinal nerves decreases when wearing the Laevo during work in a bent-over position. This has an impact on the way a work situation is assessed. A situation that typically has a health risk (lifting index> 1), could be assessed in a completely different way when wearing the Laevo during the work involved. To be able to actually say something about the work situation when wearing the Laevo, it is necessary to know what the exact impact of the Laevo is on the health risk. Two basic principles are applicable. The first principle is that one adjusts the parameters of NIOSH, resulting in an adjusted RWL, based on the properties of the Laevo. This can be used to determine for each situation separately whether there is a health risk. The other principle starts at the current risky work situation. It attempts to keep the specific situation the same, but allows the Laevo to support the situation in such a way that it is no longer considered to be high risk (lifting index <1). The first principle is elaborated and discussed below. The second principle will be elaborated and discussed in the future.

Parameters NIOSH

The adjustment of the parameters is based on empirical research conducted by the VU in cooperation with TNO. This research showed that the muscle activity of the lower back muscles in an bent-over position experienced an average decrease of 40% . There is a direct relationship between the muscle activity of the back muscles and the actual pressure on the spinal nerves[2]. Within this context, the NIOSH formula can be adjusted. The first ‘term’ in the formula is 23kg, which in an ideal situation is the maximum weight a worker is allowed to lift. This 23kg equals a pressure of 3400N on the spinal nerves and is at all times the maximum pressure on the spinal nerves without being a health risk. So there is a direct relationship between muscle activity and pressure on the spinal nerves, which is known to be a maximum of 23kg/3400N without being at risk of damage. When the relationship between muscle activity and pressure on the spinal nerves is known, one uses a simple calculation to determine the new NIOSH formula. However, experts disagree about the relationship, leading to the following two points of view:

Expert opinion 1: The relationship between muscle activity and pressure on the spinal nerves (compressive forces) is 90%. This comes from the biomechanical model of Chaffin[3]. When Laevo reduces the muscle activity by 40%, the pressure on the back will decrease by 90%*40% =36%. Translated to NIOSH, the maximum pressure on the back, without damage to the spinal nerves, will be: 3400/(1-0.36) = 5300N. This is a multiplication factor of 5300/3400 = 1.56. This can be used to calculate the first term in the NIOSH formula for the situation in which the Laevo is being worn. This is 23kg * 1.56 = 36kg. According to expert 1, the NIOSH equation for the situation in which the Laevo is being worn becomes: RWL = 36kg * Hf * Vf * Df * Af * Ff * Cf

Expert opinion 2: According to expert 2, a decrease in muscle activity of 40% is equivalent to a decrease of approximately 15% of the pressure on the spinal nerves (compressive forces). Translated to NIOSH, the maximum pressure on the back, without damage to the spinal nerves, will be: 3400/(1-0.15) = 4000N. This is a multiplication factor of 4000/3400 = 1.18. This can be used to calculate the first term in the NIOSH formula for the situation in which the Laevo is being worn. This is 23kg * 1.18 = 27kg. According to expert 2, the NIOSH equation for the situation in which the Laevo is being worn becomes: RWL = 27kg * Hf * Vf * Df * Af * Ff * Cf

We need to make several comments. The first one is that this calculation only takes into account the power one has in one’s back, not in one’s wrists, arms or shoulders. The second one is that this only applies to bending/lifting in a straight position. The effect of the Laevo is less when it comes to twisted movements and steps, in the worst case the effect is half. Envision if you will the Laevo only being used on one side. The third remark is that these calculations are based on research with the stiffest Laevo structure available, the matching parameters for other structures is still unknown.

We are currently investigating where the differences between the experts are coming from, before we take a final stand.

[1] bron: http://www.toolboxduurzameinzetbaarheid.nl/index.aspx?id=1103

[2] Dolan, P., & Adams, M. A. (1993). The relationship between EMG activity and extensor moment generation in the erector spinae muscles during bending and lifting activities. Journal of biomechanics26(4), 513-522.

[3] Chaffin, D. B. (1969). A computerized biomechanical model—development of and use in studying gross body actions. Journal of biomechanics, 2(4), 429-441.

Is Laevo a Medical Device or a Personal Protective Equipment?2018-01-17T15:06:05+01:00

Laevo has chosen to register the Laevo back support as a Medical Device Directive class I and is fully compliant with all CE-regulations (CE-13485) . This is because we expect that the Laevo will also be used in re-integration routes. Herewith, the Laevo is more than just a personal protective equipment. That is why the Laevo will measure up to all requirements of Me