| Budget Amount *help |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
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| Research Abstract |
OBJECTIVE : In electrical stimulation, the muscles contract, in order, from the more fatigable motor units to the fatigue resistant motor units (reverse recruitment). Block stimulation is a method by which to recruitment in the physiological order in electrical stimulation. The purpose of this study were to develop the totally implantabel electrodes and to evaluate the effects of low frequency block stimulation of the sciatic nerve on the medial gastrocnemius muscle of rats an effort to reduce the muscle fatigue using this original electrode.
MATERIALS : Ten extremities of nine Wistar rats were used. We isometrically measured the contraction force of the medial head of the gastrocnemius muscle of the rats.
METHODS : The frequency of drive stimulation was set at 100Hz. The block stimulation frequency was set at 20, 50 or 100Hz for each of three groups. Drive stimulation was applied for 20 sec, and then 2 sec later, block stimulation was superimposed for 15 sec. We measured maximal tetanic force at 2.4, 6, 10 and 14 sec, and calculated the strength decrement index at 6, 10 and 14 sec to yield the attenuation of muscle force from 2.4 sec to each of 6, 10 and 14 sec.
RESULTS : Block effect was seen at all three block stimulation frequencies. Muscle fatigue under block stimulation was significantly less at both 50 and 100Hz block stimulation frequencies than due to drive stimulation only (p<0.05).
CONCLUSION : These results suggest that block stimulation is a more favorable method by which to reduce muscle fatigue during clinical use of functional electrical stimulation.
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