“A road paviour should always choose a good knee protector that distributes the pressure well over the entire knee.”

Movement without pain(community- and information website)

Martijn Schaaper, founder of Ultraknee, knows as a former contractor what it is like to work on your knees every day. He noted that many of his colleagues experienced back and knee problems despite the use of protectors. This finding can be supported by research. In the Netherlands, 11.6% of the population have chronic knee complaints and 21.6% regularly suffer from knee complaints.

Because of the magnitude of the problem he went looking for a solution. He has gathered a team of human kinetics experts and engineers and has developed a knee protector in collaboration with TNO, TU Delft and The Hague University of Applied Sciences. We now know this protector as the Ultraknee Hammock 2.

“21.6% of the population regularly suffer from knee complaints”

Martijn Schaaper: A foam knee protector might offer more comfort but is not automatically better for the knees. The weight of the user largely determines the pressure on the sensitive parts of the knees. Placing a foam knee protector between the knee and the floor relieves the pressure on the knee temporarily. However, the relatively thin foam slowly collapses and will offer little to no pressure distribution at maximum compression. The Ultraknee has a sturdy plastic insert, which is strong enough to distribute the pressure over the entire knee and retains its resilient properties ”.

Measurements at TNO showed that the high peak pressure on the sensitive parts of the knee was considerably lower for the Ultraknee Hammock compared to other foam knee protectors. When one has to work on the knees for a longer time, it is often the peak pressure that causes inflammation and therefore pain in the knee. Avoiding this peak pressure results in more sustainable comfort and a reduction in complaints.


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Martijn Schaaper


Walther Schravendeel

product specialist & human kinetics expert


Hugo van de Watering

product specialist


About InMarket

We are involved in much more than just knee protectors. Ultraknee is just one of the development projects of InMarket. InMarket specializes in advising, and in design and development of products that allow users to benefit from technology. Our process can be described as user centered. By combining medical and technical expertise we are capable of solving specific problems. Other examples of our projects are:

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Innovative design rollators, such as a 2-in-1 wheelchair and rollator. These are being sold worldwide in over 25 countries.

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Water saving system for the hospitality industry. Currently more than 4000 systems have been installed and 1 billion liters of water are being saved each year.