[Experimental investigation on the reproducibility of ensemble-averaged electromyographic gait analysis data in the area of experimental and clinical orthopaedics].
With suitable application and signal processing methods, surface electromyography is a comparatively simple instrument for investigating the temporal pattern of the muscular activity of a walking subject. The influence of changes both in the external experimental conditions (e.g. orthopedic shoe design) and in the human locomotor system (due to disease or therapy) on the individual muscular gait characteristics can be documented in this way. The usefulness of this kind of investigation is basically limited by the reproducibility of the gait analytical findings of the subject, who is examined at different times with unchanged bodily state and under identical experimental conditions unchanged. In our experiments we observed that the reproducibility of electromyographic activity curves obtained by ensemble averaging over a sufficiently high number of full strides differs for different muscles and in different subjects. Within the same experimental session it is very high and considerably better than in experiments done on different days. In examinations done on different days the basic characteristics of the activity curves are reproduced better than the absolute height of the amplitudes. In view of these findings the differences observed in the gait analysis of patients in the course of operative or conservative therapy have to be interpreted very carefully as to their true origin.
Orthopädische Klinik, Klinikum der Johannes Gutenberg-Universität Mainz.
A
A
Meurer
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F
Bodem
J
J
Decking
G
G
Lenhard
J
J
Heine
D000465:Algorithms; D003627:Data Interpretation, Statistical; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004576:Electromyography / Q000379:methods*; D005684:Gait / Q000502:physiology*; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology*; D009985:Orthopedics / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity