Post-Polio Health (ISSN 1066-5331)
Vol. 9, No. 2, Spring 1993
Part II: Becoming an Intelligent Consumer of Physical Therapy Services
Marianne T. Weiss, PT, Canton, Ohio
Evaluation. Close, specific testing of the strength of each muscle is important. Gross testing of muscle groups is not appropriate in polio survivors. Specific testing is necessary because a hallmark of polio was the fact that it skipped about the body in seemingly random fashion, affecting parts of a muscle here and parts of a muscle there, sparing parts of muscle here and sparing parts of muscle there. I know of no other testing protocol other than that advocated by Florence P. Kendall, PT, that is adequate to test polio survivors. Survivors and professionals may be referred to the 1983 third edition of Kendall's book, Muscle Testing and Function, which she co-authored with her daughter, Elizabeth Kendall McCreary. Her protocol is one of manual muscle testing. Testing with Kendall's methods is easier if the patient is clothed in a manner to allow the evaluator to see the muscles being tested.
Many people think that testing should be done only with sophisticated exercise equipment that is found in sports therapy clinics or in clinics that specialize in the rehabilitation of injured workers. I feel that most polio survivors cannot be adequately tested by machines such as this, due to using abnormal substitutive movements that can potentially cause harm in the presence of significantly compromised strength. Again, I will emphasize that for individual, specific muscle testing, I know of no other protocol other than that advocated by Florence Kendall.
The only adaptation to Mrs. Kendall's techniques that I advocate, if possible, is using a hand-held dynamometer during the testing. If the PT has access to such a device and is skilled in using it, the dynamometer readings can add valuable information to a manual muscle test. For example, one muscle that grades 3+ on a 1 to 5 scale might be capable of producing only 6 pounds of force (as measured on a dynamometer) while another muscle grading 3+/5 might be capable of producing as much as 12 pounds of force.
A word of explanation regarding the grading of muscles is appropriate. The Kendalls advocate documenting muscle grades by the use of percentages, i.e., 90-100%, etc., in conjunction with the old terms used by Dr. Robert Lovett in the early decades of this century, which were normal/good/fair, etc. Another method for labeling muscle grades is using numerals 1 to 5. I have adopted this 1 to 5 grading system as being the easiest way to document on a record the value of the strength of a given muscle.
Given the above set of numbers, on a 1 to 5 scale, a grade of 3 would be approximately 50%. However, it is important for health professionals and polio survivors to understand the concepts documented in 1961 by Beasely. He found that polio survivors' muscle grades do not correspond with the above ratios. An abbreviated version of Dr. Beasely's study is listed below.
Given Dr. Beasely's study, it is important for polio survivors to understand that even though their best muscles may grade in the vicinity of 3+ on the 5-point strength scale, their percentage of normal muscle strength may only be 10 to 20%.
Another factor important to consider in strength testing is endurance. If the survivors can tolerate it, I usually have them perform three to four trials of a given motion before recording the final grade. Not infrequently I find that the first trial is significantly better than the third or fourth trial. If this is the case, I will record the value on the first trial and the value on the third or fourth trial and label them as such. It is important to recognize that a survivor may be able to put forth effort with one or two repetitions, but may not be able to duplicate that effort with sustained repetitions. In fact, in some cases a survivor may be unable to even initiate a movement after three or four attempted repetitions.
Treatment. Given all the factors above, there is a fair amount of controversy in the literature regarding the utility of strengthening programs in polio survivors. Some sources say that even in polio muscles grading 4/5, only an 11% gain in strength is possible with a concerted exercise program and that this cannot be sustained over time. The implication is that if grade 4 muscles react this poorly, then certainly strengthening for weaker muscles is also of questionable value or even contraindicated. There is also definite danger in over-exercise. At least four researchers have shown increased weakness in response to non-specific, intensive exercise.
My personal experience and recommendations are as follows:
- "Strengthening" exercise seems most useful in assisting survivors to learn more normal movement patterns. It is doubtful that true strengthening occurs, but patients seem better able to use their available strength as a result of exercising.
- All "strengthening" programs should be implemented only in the context of a person's cardiopulmonary function.
- If a person cannot perform a given motion without substituting abnormal movement patterns, it is rarely useful to attempt to "strengthen" muscles performing that motion. Doing so would only further stress over-worked muscles and further reinforce abnormal movement patterns. This sets a person up for worsening pain syndrome.
- If the muscles of a given extremity grade 3+/5 or better for 3 or 4 repetitions without substitution patterns, they may respond to a low-level "strengthening" program. Characteristics of this program might include:
a. 0-3 pounds of free weight resistance;
b. Hold count of 2-5 seconds followed by 2-5 seconds of rest, which allows for adequate rotation of muscle fiber firing without fatigue;
c. 2-5 repetitions performed 2-3 times per week;
d. Use of abdominal-diaphragmatic breathing with sustained exhalation as a means of reducing blood pressure elevation with exercise and activating abdominals to stabilize the trunk pelvis during exercise.
- If the muscles of a given extremity grade 3+/5 or better without substitution patterns BUT the extremity has compensated for years for a significantly weaker contralateral extremity, in general, it should not be stressed by further exercise. This is especially true in the upper extremities. Attempts should be made, however, to teach normalization of movement patterns, e.g., normal scapulohumeral rhythm, pelvic-trunk diassociation, etc.
- Isometric exercise may be useful for muscles grading 2-3/5 to promote circulation in that body part. Isometrics may also help retain some joint stability in body parts with this much weakness.
- Low level aerobics may be useful for people:
a. without severe heart/lung problems;
b. whose arms grade 3+/5 or greater or whose legs grade 3+/5 or greater;
c. having adequate trunk strength.
Lap swimming, walking in a pool, or biking with the arms or legs seems to be best tolerated as aerobic activities. In general, 15 to 20 minutes total aerobics (including warm-up/cool down) is the maximum recommended. Minimal resistance for biking is recommended at speeds no greater than 30 mph. Walking on dry ground is not as often recommended because of the trauma produced by abnormalities in walking patterns.
Survivors should recognize that, in general, it is considered that a muscle must have a grade of at least 3+/5 to function in ADL without external support (bracing/orthotics). If a muscle grades less than 3+/5, using that muscle during ADL without orthotic support puts that body part in great risk for developing joint instability and pain. If a person desires to avoid pain and further dysfunction, muscles with this degree of weakness should be properly splinted or braced.
Sometimes physicians or survivors are reluctant to recommend or accept bracing because they fear that, "whatever strength is there will decline." While this may be true to some extent, isometric exercise or simple anti-gravity exercise without weighted resistance will go a long way towards retaining the existing strength, even in the presence of orthotic support. At all costs, remember that the trade-off for not using adequate orthotic support in the presence of significant weakness is further pain and dysfunction.