In this industry there are companies that pour great amounts of money into research and travel the world giving speeches on how pressure injuries form. Their research explores the causes of deep tissue deformation and its relationship as to the cause of pressure injury. Pressure injuries, also known as pressure sores or bed sores, have always been a very big problem for wheelchair users so it would seem looking into the causes of this problem is a good idea. It is a good idea because the information can presumably be used in a positive way to help fight pressure sores. This is where the irony comes to play because the very same company that gives speeches on their groundbreaking research into the cause of pressure injury also makes and sells a wheelchair cushion that is arguably the most dangerous wheelchair cushion on the market.
The company is Permobil and the wheelchair cushion is a Roho cushion.
Let’s start by looking at the articles on deep tissue injury which appear on the Permobil website and then we will discuss the Roho cushion.
One article refers to Dr. Gefen, the lecturer giving a keynote presentation entitled “The Etiology of Pressure Injuries: Deformation is a cell killer”. It states he has ongoing research into understanding etiology of pressure injuries and extending safe sitting time. He talks of how the specific mechanisms of Roho static air cushions extend safe-sitting time.
A 2nd article on the Permobil website titled Groundbreaking research uncovers new insights for reducing deadly pressure ulcers in wheelchair patients. This article outlines research concluding adjustable air cushions are medically superior for reducing deep tissue injuries and skin breakdown which can lead to deadly pressure ulcers.
In the research conducted by Roho, they compared a Roho high profile static air wheelchair cushion against two flat foam-based static cushions with varying stiffness properties.
For all three cushions, immersion was calculated as the percentage of skin surface in full contact with the cushion. Higher figures represent more surface area for load transfer, and potentially lower internal tissue loads.
The different mechanical stresses – compressive, tensile, shear and effective stress were calculated.
Measures were recorded for each individual model, in the muscle, fat, and skin tissues under the ischial tuberosities during sitting, to determine the risks for the Immersion was calculated as a percentage of skin surface.
In this research they used MRI’s and finite element computer modeling to look at damage that causes deep tissue injuries. They said the immersion recorded for the Roho was better than that of the static foam seat cushion with a reading of 91 to 93 compared to 58 to 65 for the foam cushions.
They don’t indicate the thickness of the foam cushions tested which in this comparison is critical because the foam based cushions could be only 1 inch thick which will have far different cushioning and protection properties than a cushion of 3 or 4 inches thick. The immersion into the foam cushion will of course be different depending on the thickness of the foam cushion. A high profile Roho air cushion measures 4 inches tall so it would seem logical that a comparable foam cushion would also have to be 4 inches tall. However, we do not know the height of the foam cushions tested.
Roho says the results demonstrated that skin breakdown risk is much lower for an adjustable Roho cushion compared to a non-adjustable static foam cushion.
They went on to say, “air cell cushions are 10,000 times better than foam in reducing tissue damage that can cause death”. That is a pretty bold statement that I feel is untrue. I however content that a Roho cushion is significantly more dangerous and poses a much greater risk of developing tissue damage than the foam cushions they tested or any cushion on the market for that matter.
If we look at the comparison between these two types of wheelchair cushions that Roho evaluated in their research, there are similarities and some significant differences.
Both a foam cushion and a Roho cushion are categorized as static cushions. This means the cushions themselves are not able to generate any movement. They sit perfectly still until the user makes some movement and that movement impacts the pressure distribution of the posterior. This type of cushion exerts constant pressure to the posterior if the user is still.
Since we do not know the height of the foam cushions in the comparison, we do not know the degree of immersion by the user into the foam, only the stiffness of the foam cushions tested. The data in this comparison is therefore incomplete.
The significant difference between these two cushions is the actual cushioning medium. The primary component of each cushion which protects the user from bottoming out. For the foam cushions, that medium is the foam itself. The user is immersed in the foam and the foam is the cushioning material.
With the Roho cushion, that component is air. The substrate which contains the air is very thin neoprene rubber. The thin layer of rubber is exposed to environmental influences which essentially means that anything that contacts the rubber cushion can compromise the rubber and could cause a leak. This can be a puncture, friction, heat, pets or a host of other influences.
The result of a leak is the actual cushioning material, the air is gone and the Roho will then be completely flat offering zero protecton. This scenario is impossible with a foam cushion because foam cannot be there one second and disappear the next.
The air inside the Roho is the cushion medium, the only means of protection from the user bottoming out. If the Roho leaks, all cushioning and protection for the user is gone. The user will be sitting on flattened rubber and the seat pan which is the definition of bottoming out. There is no faster way to get a pressure sore than not to be sitting on a cushion.
Another interesting fact is that neither Roho, nor any of its knock offs, have an alarm to alert the user that the cushion has a leak. Roho offers no way for the user to tell when the cushion is flat and poses an extreme risk for developing potentially deadly pressure injury.
No other cushion whether it be foam, gel, composite or honeycomb can have all protection disappear like a Roho can.
Why would Permobil /Roho expend all this money, time and energy researching a cause of deep tissue injury and deadly pressure injuries and at the same time put out an air cushion with the potential to leak and cause the very same pressure injury? That is a very good question that perhaps must be asked of the people at Permobil/ Roho.
Knowing these facts which of the cushions in the Roho research is safer and which is a risk? The Roho cushion poses the greater risk of potentially deadly pressure injury.
At Aquila we concentrate on one thing. Building the very best wheelchair cushion on the market in terms of helping treat and prevent pressure sores.
Our focus is helping improve the quality of life of wheelchair users showing both tangible and intangible results. Our wheelchair cushions have proven for years to reverse the damage caused by other cushions and improve pressure injuries while the user is sitting. No other wheelchair cushion can compare.
We believe the act of building a wheelchair cushion focused on preventing deep tissue injury is far more beneficial than talking about the cause of deep tissue injury.
Aquila, the wheelchair cushion system that makes sense.