EXSS2018 Lecture Notes - Lecture 11: Differential Amplifier, Triceps Brachii Muscle, Electrical Resistance And Conductance

• School: University of Sydney
• Department: Exercise and Sport Science
• Course: EXSS2018
• Professor: Peter Sinclair

Document Summary

Introduction & uses: electromyography (emg) is a technique involved with the development, recording & analysis of myoelectric signals; records what happens in muscles and how hard they are contracting. Emg signal: time 1: muscle at rest so difference is 0, time 2: depolarization, Na+ rush inside the cell so outside becomes slightly negative: time 4: repolarization, time 5: back at rest. Many muscle fibres fire off at the same time. Emg electrodes: emg can be recorded using either surface or indwelling (needle) electrodes, fine wire electrodes: involves 2 electrodes, needle inserted into muscle, electrodes stick into muscle like hook and needle can be removed. Idea of what the whole muscle is doing = more representative. = cannot localize to where it comes from though. Emg signal: recorded emg comes from 2 sources, electrical activity from muscle you wish to measure, other electrical interference (noise - error)