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Post-Polio Health (ISSN 1066-5331)

Vol. 6, No. 3, Summer 1990
From Fifth International Polio & Independent Living Conference in Saint Louis

Prescription for Weakness

DR. MARNY EULBERG: A woman in our clinic summarized the problem of weakness very superbly when she said, "Stairs and curbs are getting higher, chairs and sofas are getting lower, and my shoes are getting heavier!"

Weakness is a symptom that comes on slowly, and we polio survivors may be unaware of it. Then one day, we can no longer push ourselves to perform in the way we had in the past, or we begin to fall, trip or drop things too many times. As a professional, I can suggest techniques or prescribe assistive devices that can be used to compensate for these weaknesses and keep someone functioning. As a polio survivor, concerns about the new weakness sometimes prey on my mind. How much weaker will I get? Am I going to be able to keep on working? Should I change jobs to one that is less physically demanding? What about recreation? Should I forget about that white water raft trip down the Grand Canyon? Should I make plans to do it in the next year or within the next five years?

I'm sure many of you have had similar questions. Are these fears rational or irrational? Today we will attempt to answer some of these questions.

DR. JAMES AGRE: In looking at a prescription for weakness, I would like to briefly discuss a number of issues including how much exercise should be done, why we should exercise, and what are the possible causes for decrease in strength and endurance in polio survivors. During this, I would like to review some of the research that we are doing at the University of Wisconsin and reach some conclusions about exercise.

What should be considered exercise? Is running in a long race exercise? Is an individual in a wheelchair participating in a ten-kilometer race exercise? Is daily activity exercise? I'm not going to be able to answer that question for you, but I believe that all of the above should be considered exercise.

Why should we exercise? Exercise has long been advocated as something that brings on good health. it can help reduce blood pressure and heart rate; increase work and cardiorespiratory capacity; increase muscle strength and endurance; reduce blood coagulability; affect insulin production levels and increase your HDL cholesterol. (An increase in the HDL cholesterol appears to reduce the risk of heart attack.)

Exercise may also lead to a number of psychological benefits, although these benefits are difficult to measure. All of us know that a routine exercise program can relieve muscle tension and, if you're not overdoing, make you feel better and sleep better. It might aid in the motivation of other health habits such as weight reduction, cessation of cigarette smoking, and dietary changes.

The importance of good nutrition and health is also becoming common knowledge. I would recommend cutting down on saturated (animal and some tropical oils) fat. Also an increase, rather than a decrease, in the carbohydrate content of your diet is important.

This is another way of decreasing fat. (Shy away from diets that are low in carbohydrates because you will be getting a high fat diet.)

There can be many adverse effects from limited activity. Deterioration in cardiovascular performance plus reduction in strength and in flexibility are among some of the possible problems related to inactivity. Other problems include metabolic disturbances and an increase in anxiety and sympathetic nervous system activity. Maintaining ideal body weight is certainly more difficult when one is inactive.

There is some suggestion that an increase in physical activity can help reduce anxiety. Many people have concluded that sport or activity will increase the years of one's life. That's a debatable issue. More importantly, activity can enhance the quality of one's life and add life to the years (even if it doesn't add years to the life). Quality of life issues are very important. For instance, one doesn't have to be extraordinarily active to see and enjoy a pretty sunset.

Let's look at some of the factors that might lead to the perception of decrease in muscle strength and endurance and fitness. One factor is not being aware of how much loss people had early in their polio. It's very hard to be aware of how much strength one had or has.

The aging process can lead to decrease in strength and endurance and fitness. The peak is reached somewhat around the age of 20 or 30. Aging is an inevitable process and with aging there can be a decline in function.

Weight gain can cause problems. Over half of our clinic population who complain of problems with ambulation and stair climbing also acknowledge that they have gained a lot of weight.

Poor nutritional habits can also cause problems with strength, fatigue and endurance. I know survivors who don't eat a good breakfast (or not at all). They may have a cup of coffee. For lunch, they have a salad and diet drink. Their main meal is dinner, but unfortunately they crash at two in the afternoon. Some of that could be depletion of carbohydrates. Loss of carbohydrate stores can cause fatigue and can affect muscle function.

Both under-activity and over-activity can cause problems. Under-activity leads to deconditioning. Over-activity leads to overuse problems. Problems with muscle pain and joint pain can get progressively worse if you try and push through it. I think the prime example of over-activity was provided by our U.S. Olympic Committee in 1984 when we had our marathon trial about two to three months before the Olympic marathon. The gentleman who was supposed to win the race took first place in the US trial, but then in the Olympics he crashed and burned. He hadn't recovered from the Olympic trials and he is, of course, a world-class athlete.

Eric Mueller looked at decrease in muscle strength with immobilization. He measured the strength of the biceps muscle of a group of 24 young and healthy individuals and put them in an arm cast to immobilize the muscles. He took the cast off at seven days to measure the strength, and then did the same thing at fourteen days. At seven days these healthy individuals lost over 20% of their strength on the average. Immobilization can certainly cause significant weakness very quickly.

Poor pacing can certainly lead to problems with decrease in strength and endurance. Muscle energy stores increase with rest and decrease with activity. With rest the energy stores become somewhat repleted; with more exercise, more depletion; repletion with rest; depletion with further work. By pacing yourself, you can keep the energy stores within the muscles from becoming exhausted.

Our research is sponsored by the Easter Seal Research Foundation. The questions we wanted answered were:
1) Is there a difference between symptomatic and asymptomatic polio survivors in strength?
2) Is there a difference in endurance?
3) Is there a difference in capacity to perform work?
4) Is there a greater difficulty in the symptomatic polio in recovering strength following exhausting exercise? and
5) Is there a difference between symptomatic and asymptomatic polio survivors regarding evidence of severity of the original polio illness?

We tested individuals who had at least grade 4 strength in the quadriceps. With some resistance, they could straighten the knee against gravity. By taking a history and by EMG testing, the severity of the polio was greater in the symptomatic group. Strength was less in the symptomatic group (60% of the asymptomatic group). However, the endurance time of the muscle was the same in all groups.

We did some electrophysiologic studies of the muscle, and they showed a similar pattern of fatigue and recovery in the muscle. It seems like the muscle is working well, but there's just less of it. Because there's less muscle and less strength in the symptomatic group, work capacity is less.

Recovery was less in the symptomatic group, and we hypothesize that this was due to the reduced number of motor units within the muscles. To study recovery, we noted recovery of strength every 30 seconds the first two minutes, and then minute by minute to 10 minutes post-exhaustion time. The control and asymptomatic groups recovered strength in similar fashion. The symptomatic group, however, did not recover strength as readily as the control group.

Interestingly and importantly, the perception of exertion (how tired the muscle was becoming) was the same in all three groups. That's not surprising, however, because polio really didn't affect sensation. (The polio mainly affected muscle strength by destroying the cells in the spinal cord that control the muscles, the anterior horn cells.) Individuals can perceive how hard it is that they're working, and I think that's a very important factor when we're looking at a prescription for exercise, especially when we see what happens when symptomatic polio subjects become exhausted; they do not recover strength very well.

We believe that a decrease in strength significantly affects work capacity and the ability to recover strength after activity in our symptomatic polio survivors.

How much exercise should you do? What exercise do you wish to do? The American Heart Association recommends at least three exercise periods per week of 20 to 30 minutes per session. But again, this is in a neuromuscularly intact individual and the heart rate is at a reasonable training rate. You should be able to talk to your friends while you're exercising. You should be able to enjoy it. You have to listen to your body. Your body really does know how much to do. It certainly will let you know when you're overdoing. If you feel fatigued the next day, then you've overdone and you will have to reappraise what you're doing. The exercise should be comfortable, pain-free, and FUN! If it's not fun, there's really not much point in exercising. By maintaining function one can enjoy life.

Recent, Related Publication

"Neuromuscular Function: Comparison of Symptomatic and Asymptomatic Polio Subjects to Control Subjects by James C. Agre, MD, PhD, and Arthur A. Rodriquez, MD. Archives of Physical Medicine and Rehabilitation, July 1990, Vol. 71. Pages 545-551.