Post-Polio Syndrome or Sequelae (PPS) is a condition that can strike polio survivors anywhere from 10 to 40 years after recovery from an initial attack of polio. PPS is characterized by a further weakening of the muscles that were previously injured by polio. PPS is usually a very slow progressing condition and often occurs after a physical or emotional trauma, illness or accident.
The first possibility is that the polio virus becomes active again after decades of lying dormant in the victim's cells. What activates it is still uncertain and is under investigation. British scientists have found polio-type antibodies in the spinal fluid of recently diagnosed PPS sufferers.
The second possibility is the evidence of impairment in the production of various hormones and neurotransmitters in brain.
Lastly, and the most promising theory of PPS, is the nerve cells (neurons) that were undamaged or partly damaged took over the functions of the dead cells. These nerve cells not only had to do their job, but the job of the damaged cells. Over time, these overworked cells began to show "wear and tear," thus the re-emergence of polio-like symptoms.
People with post-polio syndrome (PPS) tend to have problems with their feet; however, there are a lot of things that can be done with footwear to help alleviate these problems. Shoes, shoe modifications, and orthoses (also called inserts or insoles) can make a big difference in how your feet feel and how well youíre able to get around.
Common problems associated with Post Polio Syndrome:
|Pes cavus foot.||This refers to a foot with a high arch, which also tends to be fairly rigid. A normal foot is more flexible and can better handle the stress of walking; therefore, footwear for the pes cavus foot needs to have extra cushioning and shock absorption to make up for the rigidity.|
|Varus heel.||This means that the heel turns out, causing you to walk on the outside of your foot in the heel area. This causes excess pressure on your heel and up into the midfoot area because your weight is meant to be spread out over the entire heel and midfoot surface.|
|Forefoot valgus.||This means that the front part of the foot turns inward, so that the outside of the foot is higher off the ground that the inside. This puts extra pressure on the first metatarsal head. The combination of a varus heel and a forefoot valgus creates a kind of twisted foot that can make shoe fitting more difficult.|
|Metatarsalgia.||This refers to pain (suffix "-algia") in the metatarsal area.|
|Muscle atrophy.||Polio can cause the muscles to become weak and not function properly. A common manifestation of this in the foot is a condition sometimes referred to as "drop foot" where there is little muscle control in the foot and it tends to be in a position where it "drops" off at the ankle. This can often be a cause of falling; because of the lack of muscle control in the foot it tends to drag along the ground and it becomes easy to trip and fall.|
|Loss of sensation.||This is fairly rare, but in more severe cases of polio there can be a loss of sensation in the feet.|
|Falling.||People with PPS tend to fall a lot. All of the foot problems weíve talked about so far tend to make you less stable on your feet, and therefore more likely to fall, but the muscle weakness and atrophy are probably the biggest contributors to falling.|
|Toe deformities.||The most common toe deformity seen in people with PPS is hammertoes. This means that instead of being straight, the toes are permanently bent, so that they sort of resemble the head of a hammer.|
|Mis-mated feet.||People who have had polio often have feet that are two different sizes, especially if the polio affected only one side.|
|Leg length discrepancy.||Having polio on only one side can also cause one leg to be shorter than the other.|
Diagnosis of PPS is made after observing the patient, asking about the symptoms and reviewing their medical records for previous polio infection. If needed, an electromyographic study (EMG) will be done to determine which extremities have evidence of old polio. EMG is a test in which electrical activity in muscle in analyzed.
To relieve the pain of PPS, doctors may recommend nonsteroidal anti-inflammatory medications (NSAIDs) such as aspirin and ibuprofen (Advil, Motrin IB or Nuprin), and heat applications on the affected areas. While studies are limited and treatments are still being devised the best treatment therapy presently for PPS is to "take it easy."
A Post Polio Foot Drop AFO
Orthotic treatment for PPS depends mainly on the severity of the disease but in many cases the most common objective of the orthotics are, accommodation of any rigid or flexible conditions, accommodation of toe deformities, relief of excess pressure, gait improvement and the prevention of falling. Good fitting shoes with the proper modifications (flares, heel buildups etc) may also be used.
The most common type of shoe used for people with PPS is called an in-depth shoe. Itís called an in-depth shoe because it has 1/4 to 3/8-inch more depth throughout the shoe to accommodate an orthosis. A lot of todays athletic shoes can be considered in-depth shoes because they have removable insoles and therefore some extra depth. In-depth shoes also have other important characteristics that are helpful for people with foot problems.
There are a variety of shoe modifications available for PPS. Here are some of the most common:
|Extensions||If you have a leg length discrepancy, an extension can be built onto the sole of the shoe to even out the leg length and help you walk better. An extension can also be built onto the heel section for a foot that is in the "dropped" condition explained above.|
|Flares||This is when a piece of material is added onto the side of the sole to help control the varus heel. It might be added only to the heel area or it could go all the way along the side of the shoe, and will help prevent the feeling that your foot is falling off the side of the shoe. When it is built on the outside of the shoe it is called a lateral flare. A flare can also be built on the inside of the shoe for people the the opposite problem; this is called a medial flare. A flare also gives you a greater surface area that is in contact with the ground and will help you feel more stable.|
|Heel wedge||This is another way to help control a varus heel. A wedge of sole material is inserted to make the sole better match the slantedness of the heel.|
|Fiberglass lateral counter||A piece of fiberglass can be added to the outside portion of the counter to further control a varus heel.|
|Cushion heel||A wedge of shock absorbing material can be added at the heel area to provide additional shock absorption for the heel area.|
|Rocker sole||This is a specially shaped sole that helps your foot to "rock" from heel to toe during the normal course of walking. Most walking shoes are made with a rocker sole, but one can be added to other shoes. Not only does it help with walking, but when shaped properly it also helps to take pressure off the metatarsal heads.|
|Leather tip||If you have one foot that tends to drag along the ground, a leather tip can be added to the toe of this shoe to help it slide better and prevent falling. (If you have this condition, itís also a good idea to stay away from athletic shoes with lots of traction because they tend to stick to the ground and get easily caught, especially on carpeting.)|
|Velcro closing||If tying your shoes is hard work, shoes are available with a velcro closing. If you donít like the look of a velcro closure, it is possible to modify a pair of regular tie shoes to have a velcro closing but still look like they have ties.|
Follow-up is encouraged Ė often there may be adjustments or modifications necessary once you have worn your footwear for a while. This might also help to spot a problem and make a recommendation for a correction before it becomes a serious problem. As your PPS changes, your feet and footwear needs may also change.