 Richard L. Bruno
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Richard L. Bruno is chairperson of the International Post-Polio Task Force and director of The Post-Polio Institute at Englewood Hospital and Medical Center. Please e-mail questions directly to him at ppsforum@newmobility.com.
Note: This column is for information purposes only and is not intended as a substitute for professional medical advice.
Q: In January I shoveled snow and my left leg became very weak. My knee buckled twice but I caught myself before I fell. I went to my doctor and he sent me right to physical therapy. In the first session I was on the treadmill for 10 minutes, on the bike for five, and I did straight leg raises with weights around my ankles. I barely made it home, where I fell to the kitchen floor. My legs are even weaker now and they are always burning. Don't polio survivors need exercise to make weak muscles stronger?
A: Your body is answering that question for you. But let me tell you about the research on exercise in polio survivors. There have only been about half a dozen small studies that tested around 12 subjects each. The studies measured polio survivors' ability to strengthen their quadriceps muscle, the one in the front of your thigh that allows you to lift your lower leg while you're sitting and to "lock" your knee. That's the muscle that gave out when you fell in the kitchen. Although 90 percent of the subjects were said to have post-polio syndrome or reported new muscle weakness, their legs were stronger than yours. Subjects were able to ride a bike for five minutes and then lift and straighten their legs many times with weights attached to the ankles, and this was before the strengthening. Subjects then exercised two to four times a week for six weeks to two years.
The studies did differ in the way exercises were performed. Two studies asked polio survivors to limit the number of times they straightened their legs if they felt fatigue, and to rest between bouts of exercise. The amount of weight lifted was increased only if there was no "excessive fatigue." Other studies described their straightening regime as "high-intensity," "heavy resistance," or "aggressive." Two studies required polio survivors to ride an exercise bicycle for five minutes three times each week before doing as many as 30 leg lifts. In the most aggressive study, polio survivors did five minutes on the bicycle followed by a 60 minute exercise class twice a week for five months! Clearly, the subjects in these studies had more strength, more endurance, more ability to function and fewer symptoms than you do, or do the patients we treat. With this much muscle strength and endurance, the subjects certainly don't sound like they have PPS.
Way to Grow:
The Accessible Garden
By Grace Young
In spite of a disability or chronic conditions, gardening is possible for almost everyone. Gardens, large or small, offer beauty, serenity and a feeling of accomplishment ... not to mention great tomatoes!
The Walking Gardener. If you're walking and have little pain, fatigue or weakness and can bend, an in-ground garden might be doable. There are ways to bend, squat, or kneel so you don't stress or injure your back. If your legs are not strong enough to squat, sit on a low stool or on the ground.
Click here to read the full article.
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But, when you read the researchers' conclusions--for example: "a supervised training program can lead to significant gains in strength"--it sounds like exercise is just the thing to "restore" muscle strength in polio survivors who have PPS. Unfortunately, when you look at the studies' findings, the benefits of exercise are far from clear. Only 53 percent of those who exercised had an increase of about 26 percent in leg muscle strength. Twenty-six percent of subjects had no change in strength, while 21 percent had a decrease in strength of about 10 percent. So, in about half the subjects, exercise either had no effect or actually decreased muscle strength.
But there's more ... or less. Only three studies asked whether exercise had an impact on polio survivors' ability to function in their daily lives. In one study where exercise was limited by fatigue, there was no measurable change in muscle strength over two years, and half of the subjects thought their walking and stair climbing had not improved. In one aggressive study showing a 29 percent increase in muscle strength, there was no improvement in subjects' ability to do their daily activities, but there was an increase in muscle fatigue of 150 percent to 300 percent! Muscle fatigue also increased by 21 percent in another aggressive study in which strength increased by 36 percent.
With these figures in mind, you have to ask what good comes from any small increase in muscle strength if it's not related to improved functional ability but is associated with increased muscle fatigue.
Last month I mentioned Alan McComas' study showing that polio survivors who are getting weaker lose 7 percent of their motor neurons each year. McComas concluded that "polio survivors should not engage in fatiguing exercise or activities that further stress metabolically damaged neurons that are already overworking." Muscle weakness is a sign of neurons failing and dying. I know that you were taught to "use it or lose it" and to exercise until you "feel the burn." But when you feel the burn, you are burning out your neurons.
Do polio survivors need exercise to make weak muscles stronger? No. What's the bottom line regarding exercise to strengthen newly weakened muscles? Don't.
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