53. Representation of joint patterns in surface EMG

Abstract

Introduction The purpose of the study was to develop and test an experiment that will enable us to evaluate by surface EMG a conduction of flexion and extension chains triggered by reflex heel pad. Methods Electrodes were placed on two heads of the muscle Quadriceps femoris – Vastus lateralis (VL) and Vastus medialis (VM). Surface bipolar EMG signal on VM and VL and force values in the ankle were measured. EMG was measured during submaximal 60% of maximal voluntary contraction (MVC) upon knee extension in 70°. Three configurations were used to measure EMG VL and VM muscle activity: without reflex heel pad, with flexion and extension heel pad respectively. Raw EMG signal at 60% MVC was filtered and used to find 19 different types of EMG parameters (several calculation in spike shape analysis and spectral analysis were performed). Parameters were compared to test if there is statistically significant difference in between three used configurations of measurements. Volunteers: 19 healthy humans (15 women (23.5 ± 4.0 years) and 4 men (32.8 ± 11.8 years)) were used for measurement. The ANOVA method followed by post hoc analysis (Tukey method) was chosen for statistical analysis. Results The results were statistically significant (p μ V, p Conclusion The study shows that there are statistically significant changes in surface EMG patterns in situations where human subject is exposed to artificially triggered flexion or extension reflex chains. This basic setup of experiment reveals changes in EMG patterns and we speculate that this could be proved further by using HD surface EMG mapping techniques.