Contribution to the diagnostic reliability of the combined stimulation myographic/mechanographic method applied to the musculus quadriceps femoris
Laube, W.
Biomedica Biochimica Acta 45(1-2): S135-S138
1986
ISSN/ISBN: 0232-766X PMID: 3964236 Document Number: 273149
The left and right quadriceps femoris muscle (QFM) of 11 to 13-years old children and of 10 adult sportmen was stimulated supramaximally by a single shock. Simultaneously the muscle action potential (MAP) and the mechanogramm (MG) was recorded. In the MG of both groups several maxima appeared with averaged contraction times (CT) between 43-47 ms, 80-86 ms and 115-126 ms in the left as well as right position. In some cases maxima of approximately 65 ms and between 140-160 ms were found. The CT from test to retest varied about 1-7% and the amplitude about 7, 5% and 4%. The maxima of the left QFM having a CT of about 47 ms and 84 ms were significantly higher than on the right one. At the left muscle an aerobic load of 1 W/kg body mass elicited a significant reduction of the maximum by 84 ms. The remaining difference to the right muscle is 10-15%. It was concluded, that the maxima of the mean CT of 43-47 ms and 80-86 ms are those of the FTF- and STF-populations. The maxima of 65 ms should be due to the FTO-fibres and the maxima higher than 100 ms must be explained by evoked responses of the motoneurones. The reaction of the ST-amplitudes is due to extensibility changes and the remained difference shows the higher potential strength of the STF at the left muscle. Within the potentiation of the formerly recruited FTF.