Essentials of Electromyography

Product Description

The interest in and use of electromyography (EMG) have grown significantly in recent years. Researchers have found numerous clinical and research uses for EMG, including biofeedback, gait analysis, and clinical diagnosis for neuromuscular disorders. Yet, until now, few sources have been available to help novices understand the characteristics of the instrumentation, signal analysis techniques, and appropriate EMG applications.

Essentials of Electromyography provides the perfect starting point for those who plan to use EMG because it aids in the comprehension of issues ranging from handling noise contamination to the area, slope, and variability of the EMG signal. The text is also a solid reference for practitioners who use EMG, including exercise scientists, physical therapists, occupational therapists, and motor development specialists. 

The book contains six detailed chapters discussing the anatomy and physiology of muscle, bioelectricity, EMG tools, signal processing, force–fatigue relations, and gait. Through Essentials of Electromyography, readers will

• learn both fundamental and advanced concepts regarding the principles of using EMG, including the use and abuse of electrical recordings of muscle potentials;
  
• discover the physiological basis of EMG signals, which is explained at an introductory level; and
  
• explore relevant topics such as electrode configuration, advanced signal processing theory, and locations for extracting EMG information.
  

The text provides a solid review of the relationship between human anatomy and EMG as well as how EMG is applied to clinical areas. It showcases over 160 figures and many qualitative explanations to communicate the principles of EMG, the biophysical basis of EMG, and the appropriate applications of EMG. It also contains appendixes for readers with a deeper understanding of EMG and stronger backgrounds in math; those readers will have the opportunity to work through more detailed EMG calculations. The book is heavily referenced and illustrated with diagrams showing electrical circuits and the progression of electrical impulses. 

Essentials of Electromyography--which is also available as an e-book—will help readers learn how to apply EMG for biofeedback, back pain, sport activities, and other uses. The text pulls together information scattered in books and articles among the numerous disciplines that use EMG as a tool. With its clear presentation of the concepts and applications of EMG,Essentials of Electromyography will prove to be a valuable text for practitioners and students alike.

Contents

Preface
Acknowledgments
Acronyms and Symbols

Chapter 1. Anatomy and Physiology of Muscle Bioelectric Signals

• Anatomical Features of Muscle
  
• Physiology of the Muscle Fiber
  
  • Resting Membrane Potentials
    
  • Generation of the Muscle Fiber Action Potential
    
  • Muscle Fiber Conduction Velocity
  
  
• Motor Unit Features
  
  • Fiber Organization
    
  • Motor Unit Action Potential
  
  
• Techniques for Modulating Muscular Force
  
• Other Physiological Influences on the Electromyogram
  
• For Further Reading

Chapter 2. Bioelectricity

• Forces in Electricity
  
  • Electric Charge
    
  • Electric Fields
    
  • Electric Potential Energy
    
  • Volume-Conducted Potentials
    
    • The Far Observation Line
      
    • The Near Observation Line
      
    • Tripole Representation of the Muscle Fiber Action Potential
  
  
• Essentials of Electric Circuits
  
  • Capacitance
    
  • Electric Current
    
  • Resistance
    
  • Electrical Energy
    
  • Resistors and Capacitors in a Circuit
    
    • Charging a Capacitor Through a Resistor
      
    • Discharging a Capacitor Through a Resistor
      
    • The Muscle Fiber as a Resistor-Capacitor Circuit
  
  
• Essentials of Alternating Current
  
  • Conventions of an Alternating Signal
    
  • Effective Voltage and Current
    
  • Capacitance in an AC Circuit
    
  • Impedance
    
  • Cutoff Frequency for an Alternating Current Circuit
  
  
• For Further Reading

Chapter 3. EMG Instrumentation

• Electrodes
  
  • The Electrode-Electrolyte Interface
    
  • Half-Cell Potential
    
  • Electrode Types
    
    • Surface Electrodes
      
    • Indwelling Electrodes
      
      • Needle Electrodes
        
      • Wire Electrodes
    
    
  • Tissue Filtering
  
  
• Electrode Configuration
  
  • Monopolar Recordings
    
  • Bipolar Recordings
    
    • Interelectrode Distance
      
    • Selectivity
    
    
  • Considerations for Electrode Placement
  
  
• Amplifier Characteristics
  
  • Differential Gain
    
  • Input Impedance
    
    • Bias Current
      
    • Amplifier Noise
      
    • Cabling
    
    
  • Frequency Response
    
    • Bode Plots
      
    • Decibels
      
    • Filters
      
      • High-Pass Filter
        
      • Low-Pass Filter
        
      • Band-Pass Filter
      
      
    • Practical Applications
      
    • Electrode Arrays
  
  
• Grounding
  
  • Safety Grounding
    
  • Signal Grounding
  
  
• Computer Interfacing
  
  • Sampling
    
  • Horizontal Resolution
    
  • Multiplexing
    
  • Quantization
    
  • Vertical Resolution
  
  
• For Further Reading

Chapter 4. EMG Signal Processing

• Amplitude
  
  • Nature of the EMG signal
    
  • Linear Envelope Detection
    
    • Radio Signal Demodulation
      
    • Moving Average
      
    • EMG Signal Demodulation
    
    
  • Linear Envelope EMG Measurement
    
    • Area
      
    • Slope
      
    • Onset
      
    • Shape
    
    
  • Band-Passed EMG Measurement
  
  
• Cross-Correlation Function
  
  • Background of the Correlation
    
  • Calculation of Cross-Correlation Function
    
  • Muscle Fiber Conduction Velocity
    
  • Electromechanical Delay
    
  • Cross-Talk
  
  
• Frequency 
  
  • Fourier Series
    
  • Frequency Spectrum
    
  • Power Spectrum
    
  • Fourier Transform
    
  • Frequency Spectrum of EMG
    
  • Power Spectral Density of EMG
    
  • Discrete Measures Obtained From the Power Spectral Density Function
  
  
• Data Window Length 
  
• Noise Contamination
  
  • Signal-to-Noise Ratio
    
  • Inherent Noise
    
    • Electrode Noise
      
    • Amplifier Noise Sources
    
    
  • Interference Noise
    
  • Signal Averaging
    
  • Baseline Noise Spectrum Subtraction
    
  • ECG Contamination
  
  
• Basic Concepts of Digital Filtering
  
  • Residuals Analysis
    
  • Digital Filtering
  
  
• For Further Reading

Chapter 5. EMG–Force and EMG–Fatigue Relationships 

• Relationships Between Muscular Force and EMG 
  
  • EMG Magnitude and Muscular Force
    
    • Studies Using Isometric Contractions
      
    • Studies Using Nonisometric Contractions
      
    • Studies Focusing on Other Factors
    
    
  • Frequency Analyses
  
  
• EMG Analysis During Fatiguing Contractions
  
  • EMG Amplitude During Fatigue
    
  • Spectral Frequency Characteristics
  
  
• Advanced EMG Issues During Fatiguing Contractions
  
  • M-Waves During Fatigue
    
  • The Importance of Muscle Length
    
  • Shifts In Spectral Frequency During Fatigue
    
  • Other EMG–Fatigue Reporting Techniques
    
  • Reliability of EMG Measures During Fatiguing Contractions
    
  • Other Issues and Recommendations
  
  
• For Further Reading

Chapter 6. Other EMG Applications 

• EMG and Gait
  
  • Indwelling or Surface Electrodes?
    
  • Normalization
    
  • Appropriate Quantitative Measures
    
  • EMG Onset–Offset Analysis
    
  • Visual Presentation of EMG Data During Gait
    
  • Other Gait EMG Issues
    
  • Reliability of the EMG Signal During Gait
  
  
• EMG Activation Timing
  
  • Threshold Detection
    
  • More Complex Techniques
  
  
• Evoked Potentials
  
  • M-Waves
    
  • H-Reflexes
    
  • V-Waves
    
  • F-Waves
    
  • Peripheral Nerve Conduction Velocity
    
  • Other Evoked Potentials
  
  
• Ballistic Movements
  
• For Further Reading

Appendix 2.1 Calculation of Electric Fields 
Appendix 2.2 Calculating the Electric Potential at a Point
Appendix 2.3 Electric Circuits
Appendix 2.4 Charging a Capacitor Through a Resistor
Appendix 2.5 The Muscle Fiber as an RC Circuit
Appendix 3.1 Muscle–Tendon End Effects
Appendix 4.1 EMG Area and Slope Measurement
Appendix 4.2 Cross-Correlation Function
Appendix 4.3 Calculating Fourier Coefficients

Glossary
References
Index
About the Authors

Audiences

Reference for exercise scientists in motor control and biomechanics, biomedical engineers, physical therapists, occupational therapists, athletic trainers, motor development specialists, and researchers. Text for students in courses using EMG technology.