Category: Wheelchair Seating

By: Fiona Smith, Occupational therapist HBDHB & Megan Ransley, Sales Area Manager, Physiotherapist Morton & Perry

Background

This case describes the situation of a 46-year old male: Mr. S. Mr. S suffers from end-stage kidney disease (not palliative) and is on hemodialysis three times a week. He underwent a right below-knee and left below-knee amputation in subsequent years. Furthermore he is diagnosed with peripheral neuropathy, hypertension, type two diabetes that is poorly controlled and diabetic retinopathy. Mr. S. lives alone in his own home. Despite being unable to work, he was mobile, independent and active. His first amputation concerned his right toe as a consequence of gangrene. His right lower leg was later amputated due to an infection and non-healing of the toe wound.
In the subsequent year his left leg was amputated below the knee due to a non-healing and necrotic left heel ulcer. Mr. S. was in considerable pain due to the ulcer. Due to significant small vessel foot disease and no revascularization options he chose to have the second amputation. Mr. S. was fitted with a basic self-propelling manual wheelchair with a basic flat foam cushion following his first amputation. It was hoped that Mr. S. would be fitted with a prosthesis after healing of the stump and that he would return to independent mobility. This goal was however not achieved due to the very slow healing of the wound.

The Problem

Mr. S.’s problem situation consists of a threefold of things:

• The manual wheelchair he was issued did not meet his physical and functional needs. He was unable to self-propel effectively due to poor configuration of the wheelchair.
• He demonstrated a poor sitting posture in the wheelchair. He was positioned in a posterior pelvic tilt causing him to slide forward. In further assessment it was established that his posture was fully flexible and that the canvas back support and seat had become slung and were making his posture even worse.
• The wheelchair cushion did not afford Mr. S. sufficient pressure redistribution as he indicated a sitting tolerance of approximately an hour. After which he would experience pain under both ischial tuberosities (Its) and in his sacral region. Despite being able to weight shift independently he could not sit in his wheelchair comfortably all day and needed to switch to different surfaces to reduce discomfort.

Actions taken before using Vicair

In an attempt to improve his positioning and try to meet his needs, the wheelchair was reconfigured. The rear wheels were brought forward, to improve access to the push rims. The front-and-rear-seat-to-floor-height was adjusted to enable safe transfers. The changes however turned out to be insufficient to assist Mr. S. in his daily functioning and position him comfortably.

Implementing Vicair into the seating solution

A trial was started with the Vicair Active (9cm) and a Vicair Adjuster 12, of which we will discuss the details shortly, however, two other adjustments were made to the seating system that are relevant to the situational assessment:

• S. was issued a TA-iQ front-wheel drive power wheelchair with tilt and HiLow. This enabled him to access his him and the community independently without experiencing the fatigue that was caused by self-propelling. This new wheelchair configuration would also allow for future-proofing of foot placement prosthetics.
• A firm contoured back support was fitted to his wheelchair: nxt Active Contour height-adjustable backrest. This back system assisted in facilitating an upright position and prevent slumping.

Pressure mapping comparisons

Pressure mapping was undertaken on all three cushions: a foam cushion, the Vicair Active (9cm) and the Vicair Adjuster 12. Single peak pressures seen over the ITs sitting on the foam
cushion were eliminated as the legs could be used as weight-bearing surfaces.

Foam cushion

Pressure mapping of the foam cushion demonstrated that Mr. S. was weight-bearing significantly through both ITs, but in particular the right with a peak of pressure seen there. It also demonstrated that Mr. S.’s weight was unevenly distributed with almost no weight being taken through the thighs. The picture showed a small surface area of weight-bearing. This cushion allowed only one hour of sitting before pain was experienced in the ITs. It is likely that over time the foam was compressing and the cushion’s pressure redistribution properties were diminishing.

Vicair Active (9cm)

It was thought that the firm front of the Vicair Active 9 would enable safer and easier transfers while affording the pressure redistribution Mr. S. required. As can be seen from the pressure mapping images, significant improvement was made in relation to the pressure redistribution with a much larger surface area taking weight. This cushion was adjusted by removing 5 cells from both the left and right compartment to allow immersion. Mr. S. commented that the cushion felt comfortable and supportive. He sat well with an improved upright posture. He managed to transfer with ease.

Vicair Adjuster 12

Trial of the Vicair Adjuster 12 cushion was carried out as a comparison. Mr. S. immediately commented that this cushion felt even more comfortable. This is likely because of the depth of
the cushion. Mr. S. is a heavy man and could immerse deeply into the Adjuster 12 cushion without the need for cells to be removed. This deep immersion afforded a greater surface area over which his weight was distributed, giving even pressure redistribution and the feeling of greater comfort. The greater immersion available from the Vicair Adjuster 12 cushion also enabled Mr. S. to feel more stable within his wheelchair. The pre-ischial bar provided a barrier to the pelvis sliding forward.

Shear forces

As Mr. S. indicated the sensation of sliding forward in his initial seating system a shear force assessment was made by using iShear. This demonstrated that Mr. S. was experiencing not only downward pressure but also dangerous forward shearing forces (sliding force). Shear forces were reduced from 125.5N on the foam cushion, to 83.2N on the Active 9 cushion, then to 62.2N on the Adjuster 12 cushion. This demonstrates that Mr. S. was able to sit more upright, with less sliding forward. The reduction in shear force is likely contributing to the preference towards the Adjuster 12 cushion the increased comfort and to improved sitting tolerance.

The Conclusion

Mr. S. is now comfortably using his new powered wheelchair with the Vicair Adjuster 12 and nxt backrest. He is able to remain in his wheelchair comfortably for the duration of the day. He can now use his wheelchair without the risk of pressure and shear related injuries. The new configuration allows him to safely and independently access his home and community.
The Adjuster 12 provides Mr. S. with high-pressure distribution properties that are needed to enable him to sit safely and comfortably all day. The pre-ischial bar prevents him from sliding forward, whilst deep immersion provides stability. Furthermore the cushion is low maintenance and easy to understand. The Vicair Adjuster 12 turned out to be the ideal product choice and solution for Mr. S.

By: Carlos Kramer, Head of Education Vicair

Background

In this case we will discuss the situation of a 53-year old male: Mr. R. He was diagnosed with small fibre neuropathy in 2014 which displays itself in nerve pain from the fingertips to the toes. It also affects the autonomic nervous system, which causes gut, bladder, stomach problems and reduces muscle tone. Mr. R. suffers from chronic pain and fatigue in addition to spasms that show in his fingers and legs, especially when he’s sitting on a couch or laying in bed (resting position). He also catheterizes, but is still able to urinate normally.
A medication cocktail is used to help ease Mr. R’s situation, it consists of anti-depressants, anti-epileptica that need to assist in falling asleep in addition to pain killers. Mr. R. makes use of a manual wheelchair and tries to walk as much as possible. He has no history of skin breakdown. Lastly, Mr. R. has an ankle flexion limitation.

The Problem

In his current seating solution Mr. R. suffers from pain in his buttocks, due to atrophy. He experiences the pain mostly under his sitting bones (IT’s). He experiences neuropathy pain when areas are pressured. A very basic example of this is when drying his legs with a towel after a shower, 30 minutes after the activity he still suffers from pain.

The situation before Vicair

Mr. R. makes use of a Quickie Helium wheelchair that was fitted with a Jay basic cushion. His back is a tension adjustable system. He experienced pain from the seat cushion and felt like a lot of pressure was being caused by the cushion. In order to assess the current situation a pressure measurement was done via pressure mapping (figure 1). The pressure map confirmed the sensation described by Mr. R. as a lot of pressure is shown in the IT area.

Implementing Vicair into the seating solution

In order to redistribute pressure the Vicair Adjuster O2 (6cm) was introduced. This model’s known quality for equal pressure distribution was thought to solve the pressure spikes shown in
the pressure map. Another pressure measurement was conducted when the wheelchair cushion was implemented into the seating system. The measurement (figure 2) shows a significant decrease in spiked pressure points and an overall redistribution of pressure, which would hopefully in time result in less pain.

The Conclusion

After three weeks of testing his new Vicair Adjuster O2 (6cm) cushion in his manual wheelchair, Mr. R. experienced a significant improvement. He no longer had the sensation of sensitively painful sitting bones. Overall the pain that he experiences has been reduced, hence the Adjuster O2 was a welcome change.

By: Carlos Kramer, Head of Education Vicair

Background

At the age of 12, a series of medical procedures started for Mr C as he was diagnosed with epiphysiodesis. This meant that due to an accelerated growth process in puberty, a deformation of the hip and hip socket was starting to form. As a result, there was also hardly any cartilage left in his hip joints.

He underwent a series of surgeries from his 12th year onwards in an attempt to slow down the accelerated growth process. This involved placing and removing metal pins in his hips.

Now at the age of 25, his opinion is that the surgeries had divergent effects and that he is still looking for a real solution. The deformity in his hips initially caused Mr C.’s legs to be positioned outwards (V-shape).

In his last surgery, doctors attempted to reposition his legs more inwards by vertically cutting one of his femurs. According to Mr. C., this had devastating results causing only more discomfort and he therefore refused further surgery on his other leg.

Mr C. has no history of skin breakdown or pressure ulcers whilst using his custom-made manual wheelchair. He also does not make use of any medication. In his leisure time, Mr. C. loves to swim and he cycles with a high-end handbike – he is a young active individual. Due to his fixed hip rotation as a result of his epiphysiolysis, he makes use of his wheelchair in almost all daily activities.

The problem

This case mainly revolves around a positioning and stability challenge. His adjusted manual wheelchair is set up to fit the negative anterior wedge in his hips. This in practice means that the seating surface is set up in a downward angle towards the front of the wheelchair.

The wheelchair has almost no back support, has a hip belt positioned around the sias, and features foam knee blocks and a 3D space fibre cushion that facilitates breathability and microclimate control.

The current seating system however lacks stability for the ideal position. Mr C. needs to reposition every 5 to 10 minutes in order to be comfortable.

He feels like he is constantly sliding forward despite his belt, resulting in a lot of pressure on his lower legs just below the knees (on the kneepads).

This results in redness of the skin in the knee/lower leg area. He is bothered mostly by the lack of stability when he is actively moving around in his wheelchair. He often chooses to keep moving in the uncomfortable position and reposition when he reaches his ‘destination’.

Repositioning in itself is a tardy process in which he always needs to release the belt, reposition and fasten the belt.

Expressing the problem in numbers

Due to his wheelchair being set at a permanent angle to better fit his fixed hip rotation, there would naturally be a tendency to slide – as confirmed by Mr C. in describing his problem.

An iShear measurement could therefore provide a lot of insight into the shear forces created by his set-up that cause the pressure on his knees. Three different situations were measured with iShear: positioned in the wheelchair without knee blocks or belt; with knee blocks and with knee blocks and belt.

iShear shows an off-the-chart measurement of shear forces when Mr C. is positioned in his wheelchair without any aids. When the knee blocks are applied an overall reduction of 7kg in shear forces is observed.

This means that the kneepads hold a force of 3,5kg per knee.

Even though the knee pads provide a reduction in shear forces, the amount of force that is left over shows that there must be a significant amount of pressure put on the knee pads.

This corresponds with the indication Mr C. gave about the redness of skin in this area.

Surprisingly the shear force measurements by iShear show mixed results when the hip belt is applied. Depending on how Mr. C. (re)positions himself the belt can have a positive, negative, or no effect at all on the amount of shear force.

Seeing that he repositions himself very often, there’s a chance that he repositions himself into an even worse position (more shear force, more pressure on the pads) and locks this with the belt. In such a “wrong” position the belt forces Mr. C. down his seat even more, increasing the sliding effect down the fixed seating surface.

Actions taken before Vicair

Over the years, Mr C. had several wheelchairs and cushions in an attempt to better suit his needs and make him more comfortable.

None of the changes succeeded in offering a solution to his seating challenge. The current set-up was the best achievable result so far.

Implementing Vicair into the seating system

It was obvious that the sliding effect (and thus shear forces) were created by the fixed angle of the wheelchair set-up, the inability to immersion into the 3D space fibre cushion only further amplified the situation.

The texture of the cushion in place even felt like it would stimulate sliding and create friction.

Theoretically speaking this sliding on the fixed, angled seating surface could be decreased or stopped by positioning Mr C’s ITs on a flat seating surface. A flat foam piece under his ITs however feels very hard and uncomfortable.

Therefore a different solution was chosen: the combination of a wedge – that would cancel out the sliding angle – and a Vicair cushion.

The image below displays the plan in a simplified way.

Keeping in mind Mr C’s request for stability, the Vicair Vector O2 (6cm) was chosen as the preferred cushion to fix the problem at hand. It’s the most stable cushion in the Vicair range and is known for ‘forcing’ people into a correct position.

The front compartments of the Vector would also support leg alignment. A foam wedge was placed under the two middle compartments in the back of the Vicair Vector O2. It was fixed into the right position by making use of Velcro on the Vector’s cover.

The foam wedge created the flat seating surface under his ITs where the two SmartCell-filled compartments above it would provide the comfort that foam alone couldn’t offer. In addition to changing Mr C’s wheelchair seat cushion, Vicair knee pads were made to fit his knee blocks.

Implementing the SmartCell technology into the knee pads would hopefully redistribute the pressure created by the shear forces on the knee blocks, resulting in less redness and discomfort. Because the Vicair Vector O2 (6cm) was higher than the original 3D space fibre cushion the filling grade was adjusted to facilitate a comfortable position with regards to the distance to the wheels of the chair and manual movement.

Conclusion

During the fitting process of the clinical assessment, an immediate change was already noticeable. In testing and adjusting his new cushion, Mr C. no longer felt the need to fasten his hip belt.

On top of that, he made several test rounds around the facility in his wheelchair and he did not feel the need to reposition.

A definitive conclusion about the solution offered could only really be made after a longer period of testing.

After two weeks of testing his new set-up, Mr C. indicates that he barely uses his positioning belt anymore.

Mr C describes his new Vicair knee pads as being ‘perfect’, he experiences less pressure or better-distributed pressure and clearly observes less redness in his knees.

Ideally, Mr C. would like to be positioned a little bit lower for easier reach to the wheels whilst moving around. Despite the reduced amount of cells in the Vector O2, the cushion is still a little bit higher than the old one. Together with Vicair product specialists, Mr C. is now exploring the options to further optimise his positioning on a Vicair wheelchair cushion.

Meanwhile, he is very satisfied with the improvements so far and moves around without any restraints.

By: Carlos Kramer, Head of Education Vicair, The Netherlands

Background

In 1943 Mr. R’s parents noticed something was amiss with their young son, at barely 3 years old his right leg started bothering him and after a doctor’s visit they were told their son probably had flatfeet or suffered from short-term paralysis in his right leg.

As time passed, the problems however only got worse to the point of being unable to walk. His parents pressed for a second opinion from the Sint Maartenskliniek in Nijmegen, the Netherlands, and quickly a relatively rare diagnosis was established: polio.

 

His right leg had been affected and as a consequence had lagged in growth and muscle strength.
Now aged 78, Mr R has a rich medical history with a number of key points that played a primary part in the condition of his health and mobility.

Throughout most of his life, he made due with orthopedic shoes to assist him in walking. In ’99 he broke his right hip after stepping off a ledge, losing his balance and as a consequence falling. It’s very likely that the imbalance and fall were caused by the limitation in his right leg. The head of his hip was broken and via surgery reattached with a metal pin.

After a lengthy rehabilitation process at several institutions, Mr R. ended up seeing one of the country’s experts in post-polio at the Amsterdam Medical Centre (AMC) and was assigned an AFO (Ankle Foot Orthesis).

After several measurements and tryouts, he became more mobile again. At the request of the AMC, he participated in a study researching the effects of an AFO for post-polio patients.

In Mr R’s individual case, a significant increase in the development of muscles was observed. For the study, he went through a general health check which he passed with flying colours apart from a minor deviation in his bladder which could be fixed.

As doctors examined further, they found something else and in 2011 Mr. R. was diagnosed with prostate cancer. Signalling the beginning of a further deterioration of his health and quality of life. Even though Mr R has now officially been declared cured of cancer, it greatly affected his physical well-being.

Radiotherapy affected his intestines and as a result, he is now dependent on catheterisation and flushing his intestines. Due to the illness, he also lost a significant amount of muscle strength and is now for two years dependent on his wheelchair for most of his daily activities.

The problem

This case focuses on the importance of proper positioning and creating stability when there needs to be dealt with a difference in body mass in the seating surface, even pressure distribution is also important to safeguard skin integrity in an asymmetric position. Polio affected Mr. R’s right leg which can both be observed in the difference in length and muscle mass. There’s a 4cm difference in circumference between the right and the left leg just above the knee.

Due to this difference in muscle mass, Mr R is always positioned slightly crooked. In his current set up he also feels that he slides forward in his chair, indicating unstable positioning.

In addition, he indicates being uncomfortable and not being able to sit in his chair all day and feeling fatigued. The crooked position is confirmed when we conduct a pressure mapping measurement. As can be seen in figure 4 there’s a clear difference in pressure between the two sides. More pressure on his left leg could possibly also be the cause of the discomfort that he describes.

Existing set-up before Vicair seating system.

Mr R. showed us two cushions, one that was a standard cushion delivered with the wheelchair that has never really been used. This to the fact that this was never prescribed as a flat cushion could never support the asymmetry in his body. In response to this demand, Mr R received a Jay Easy Visco to better fit his needs for a contoured cushion.

The pressure map displayed in Figure 1 shows the situation when Mr R was seated on the Jay Easy Visco, hence his problem was not solved with this contoured cushion.

Implementing the Vicair seating system

The difference in mass along his right leg creates an asymmetry in his seating position. In a case with asymmetry, you could normally expect to make use of the Vicair Adjuster O2.

However, in this case, the choice fell upon the Vicair Vector O2 for precision positioning and accommodating the difference in mass along the entire leg rather than just supporting the asymmetry it causes in the hip area.

The extra compartments in the Vector O2 allow for precision positioning along the entire leg. The front compartments in the Vector O2 would also support his legs, improving leg alignment and stability of his legs whilst seated. First Mr. R’s position was assessed in an unadjusted Vicair Vector O2.

This is in order to make a proper judgement of where adjustments needed to be made. The assessment showed that, as expected, some adjustments needed to be made. The images show the differences in pressure between the Vicair Vector O2 in its standard configuration and the adjusted version.

The pressure maps show that the pressure has been significantly decreased.

The unadjusted Vector O2 was already an improvement in comparison to the Jay Easy Visco. The adjusted VectorO2, however, shows even more pressure improvement and we can now also see the leg support the cushion provides represented on the pressure map.

Cells were added on the right side of the cushion to accommodate for the missing mass and a number of cells were taken out on the left where the normal leg is positioned. Figure 7 shows the adjust filling grade of Mr R’s Vector O2.

Conclusion

Immediately after the adjustment, we can observe an improvement in Mr R’s position. It was easily spotted by the line of his shoulders that is now positioned straight.

He also immediately indicates that he feels more supported. A longer testing period should point out of the cushion also delivers the desired results for the long term. After about a month of testing, Mr R is still positioned nicely straight in his wheelchair on the adjusted cushion. He, however, indicates that he has a new fitting shoe for his AFO and received new leg support for his wheelchair.

His seating set-up has therefore changed a bit but he has easily adjusted the cushion by adding and removing a number of single cells in compartments. This does, however, indicate that a different AFO has an influence on his positioning and therefore new shoes in the future might further affect his position in the wheelchair.

The combination of his new shoes and feet supports created a higher positioning of the thighs and it was therefore decided to create a foam wedge under the front of the cushion to make up for the distance that has been created and re-establish the support on the legs fully. This would be a temporary solution as the arrival of his new AFO might change the situation again.

In addition, Mr. R tells us that he no longer experiences the sensation of sliding forward. A very positive change is that he now also prefers to stay in his wheelchair for daily activities. In restaurants, for example, he used to transfer to another chair but now prefers to stay in his wheelchair. It shows a high level of comfort that he now can remain in his chair all day. Last he indicates using his new Vector O2 on holiday this summer during hot weather and confirms that the cushion’s breathability really supported temperature control – his old cushion was a lot warmer.