Security issues are concerns about safety. They involve activities or movements that elicit fear. We don't want to get hurt. In the case of physically challenged individuals, the fear is usually of falling. Security Issues are based on actual events and justifiable concerns. An example of a security issue for anyone is walking on ice. One discovers quickly that they must alter their walking strategy. It may be based on a previous experience or the mere fact of losing control without actually falling. One soon learns to alter their walking strategies. Most people will crouch down a little and spread their feet out. This lowers the center of gravity and increases the foundation. The concentration required for movement is intense and becomes the primary focus of attention. Shorter steps or even shuffling the feet without lifting them is safer. Arms are spread out to help with balance. All these compensations are made to reduce the security risk. If these strategies don't work, it may be necessary to get down on all fours and crawl to safety.
It is human nature to make compensations for security reasons. Security issues in Post-Polio can become a routine part of daily life. This may happen gradually over time with aging or early affects of Post-Polio Syndrome or are a way of life since the initial onset from the polio virus. Each falling episode has a cumulative effect. Ultimately ambulation becomes a conscious effort. Normal ambulation is an unconscious activity. Security issues can make ambulation a conscious activity. This creates compensations, balance problems and a lack of efficiency. Until the security issues have been solved, compensations will be made. In the case of a typical individual on ice, the security issues are eliminated upon reaching dry ground. For the individual with Post-Polio, security issues become ingrained in the subconscious mind; in other words, the compensations become normal in spite of the lack of efficiency. Understanding that they exist, recognizing and understanding their purpose and providing a solution can return security and efficiency to near normal levels.
Security issues causing compensations in Post-Polio are learned activities. They ultimately become habits. Each person demonstrates unique characteristics and degree of severity. The most common examples of security issues in gait are decreased standing and walking balance, tripping over the feet, ankles rolling over and for some, knees buckling.
Difficulty with balance is one of the most common security issues in Post-Polio. This is caused by a combination of weak or no muscle power and progressive deformities. The foot and ankle complex; as well as, the knee are the most common structures affected by progressive deformities. Balance is normally maintained by a complex array of neuro sensors, muscles, and proper structural alignment.. This is called proprioception. Proprioception can be defined as the awareness of the body in space or the awareness of the position of a body part without visual cues. As the body leans too far, sensors send messages to activate muscles to oppose that movement and return to the original upright position. In Post-Polio, the sensors are usually working that provide proprioception but the muscles may not be working properly. Instead of small activation of a few muscles to maintain standing in one place, the individual with Post-Polio often recruits other muscle groups to compensate to right themselves. Rather than subtle isolated muscle contractions to maintain balance, the recruited muscles are usually at a mechanical disadvantage and must activate longer and stronger to accomplish a similar task. This is often at the price of efficiency and over taxing the system.
Tripping or the loss of balance heightens the awareness of security issues and the fear of falling. The most common compensation is to lift the whole leg high enough to clear the foot that is dropping. As weakness progresses, the leg must be lifted higher. This compensation is called high steppage gait. One must lift15% of one's body weight straight up against gravity on each step. This involves increased energy expenditure and creates balance problems.
The ankle rolling over also affects balance and the fear of falling to one's side unexpectedly. This is caused by deformities from an imbalance of muscles. Certain nerves are affected more than others, thus affecting the precious balance of muscle strength.
People with Post-Polio tend to have structural deviations caused by muscle imbalance and/or lack of proper support under load bearing applications. Some Polio survivors have a discrepancy that causes excessively high arches called pes cavus. As the deformity increases, the ankle is very susceptible to rolling over to the outside. Falls, ankle sprains, and even fractures are all quite possible and common. The compensations are spreading the feet, slowing down, shorter steps, quicker steps and no longer shifting one's body weight over the feet. Ultimately, balance becomes impossible.
The buckling of the knees is very common, the resulting security issue dramatically increases the chances of falling. To prevent the likelihood of knees buckling, one will start snapping their knees backwards on each step. This creates hyperextension at the knee. (also called recurvatum) This repetitive compensation in time stretches the structures on the back of the knees. The structures involve ligaments, tendons, joint capsules, nerves and blood vessels. The recurvatum is classified as mild, moderate and severe and will progress if not prevented. Pain can also be associated with recurvatum. To be secure, one rapidly moves 15% of their body weight 180 degrees away from the intended forward direction. A secondary compensation often associated recurvatum is the forward movement of the upper body over the weight bearing leg during stance. Before a step can be taken on the ot