James W. Fee Jr. MS
Katherine T. Samworth PT, BEE
Alfred I. duPont Institute
1600 Rockland Road
Wilmington, Delaware 19803
INTRODUCTION: A previous pilot study indicated that a vertical bouncing motion may effect muscle tone in some subjects with cerebral palsy. The present study continues to investigate this and other possible effects using a larger sample size and additional testing.
MATERIALS AND METHODS: 30 subjects with spastic cerebral palsy ranging in age from 6 to 21 years of age, will be tested twice before and twice after riding (while seated) on a platform. The platform will move them up and down 3 inches at approximately 1.5 Hz. Tests before and after riding include: the leg drop pendulum test for spasticity with surface electromyography measurements of the quadriceps and hamstring muscles, a modified popliteal angle measurement, an expiratory volume measurement, heart rate and a sway test for balance.
RESULTS: 19 of the 30 subjects have been tested as of abstract submission data. Results vary widely. Statistical analysis will be performed after all subjects are tested. Preliminary results show that there may be before/after changes in the following: Increased expiratory volume in 8 subjects, increased sway motion in 4 subjects and decreased sway motion in 4 subjects, decreased heart rate of 4 subjects and increased heart rate of 3 subjects, in the leg drop pendulum test changes in tibial rotation were seen in 7 subjects, changes in hip internal/external rotation were seen in 3 subjects and changes in knee flexion/extension were seen in 2 subjects. One subject did not show a change in any of the tests. A subject that was diagnosed with Attention Deficit Disorder as well as cerebral palsy showed a dramatic change in behavior during and after the vertical motion.
DISCUSSION: Changes seen in the previous pilot study seemed to indicate a "relaxation" effect in many subjects which was thought to be due to a decrease in spasticity. Changes seen so far in this study have not been as dramatic as the changes that were seen in the previous pilot study. This study uses an extra baseline measurement which shows that just sitting for an extra 10 minutes without intervention tends to have a "relaxation" effect. Actual effects of the vertical bouncing motion may be more subtle than previously thought. Even so, some interesting results have surfaced during this study. When changes were seen in expiratory lung volume, there was consistently an increase. This could indicate a relaxation of the muscles of the diaphragm thereby allowing the subject to take a deeper breath. Balance testing shows that some subjects show an improved ability to hold still while others appear to be more wobbly following the vertical motion. If there is indeed a reduction of spasticity, some subjects may benefit by using normalized tone to hold still while others may have some difficulty holding still with decreased tone.
CONCLUSION: Results seen so far in this study have varied from subject to subject. These variations are not surprising. Even though all of the subjects have a diagnosis of spastic cerebral palsy, they do vary in their functional abilities and with their level of spasticity. The pattern of results may become more apparent when the study has been completed.
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