未熟児における筋圧入度の研究

抄録

An apparatus based on the electrical modification of "Mangold's Myotonometer" which gave a continuous estimate the muscle consistency, was used to measure one of the biceps brachii and gastrocunemius muscles in the premature infants.
Thirty premature infants, consisting of 13 males and 17 females, served as test subjects during first 4 weeks after birth.
1. At several hours after birth, the biceps brachii muscle has a harder consistency than the gastrocunemius, but after first week-old there was no difference between two muscles.
2. The muscle consistency of the biceps brachii presented harder at the extensive position than at the flexion. This contrary results to expectation seemed to be due to the difference between the passive and the active flexion.
3. With respect to the maturity, the muscle consistenc y didn't depend on the birth weight, but largely on the duration of pregnancy: i. e. the shorter the duration, the harder the consistency.
4. The develo pment of the muscle consistency presented that the consistency by the 5 th day was soft and by 1st to 2 nd week that hardness increased. This hardne s s showed a tendency to decrease after 4 week-old and finally reached a fairly stable level. That findings have great resemblance to the one of the mature infants, but presented slower development in the premature infants.
5. Thickness of the subcutaneous tissue didn't act on the measurement of the muscle consistency, because it was almost fixed during first 4 weeks after birth.