<p> The interrelationship of force, surface elecrograms (EMG) and
joint position for static voluntary contractions of Quadriceps Femoris
muscle group in man were investigated before and during partial curarization
induced by d-tubocurarine. </p> <p> Four normal male volunteers were studied. Each performed a series of brief isometric contractions (by extension of the lower leg against
resistance) at different levels of force and at three knee-joint positions
while lying in the supine position. All series were repeated
for both a normal state and a partially paralyzed state under the :influence
of curare. Torque generated about the knee-joint was measured
with a Cybex isokinetic system and the nyoelectric activity of three
quadriceps muscles was monitored using bipolar surface electrodes. </p> <p> Traditional parameters of nyoelectric activity (mean-rectified-EMG
[MRE], and root-mean-squared-DG [RMSE]) were calculated using a
minicomputer (PDPll/34), which had also acquired and processed the
data. In addition, EMG power spectra were computed by Fast Fourier
Transform techniques in an attempt to provide further insight into the
effects of curare on human muscle. </p> <p> In order to provide a basis for comparison of the normal state with the parially curarized state, force-EMG relationships were computed for each subject, muscle, knee-joint angle, and condition. Statistical
methods (three-way ANOVA' s) were then employed to both quantify
any differences that may have existed between the two states and to identify sources of differences within each state. A similar statistically-
based comparison of the power spectra was undertaken utilizing
several indices that described the shape of the spectra. A general
description of the activities of the quadriceps femoris muscles followed
after collating all the information that the surface DIG provided
in conjunction with the external forces measured. </p> <p> It was concluded that curare did not have any significant effects
on the force-EMG relationship. There appeared to be a slight effect of
curare on the power spectra however, with a general trend of increasing
lower frequency power. The greatest source of variation of force-EMG
relationships and power spectra was attributed to the position of
the knee-joint. </p> / Thesis / Master of Engineering (MEngr)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/20159 |
| Date | 10 1900 |
| Creators | Shein, Graham |
| Contributors | Pengelly, L. D., Engineering Physics |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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