An EMG (electromyography) measures the potential difference in muscle activity and comes in three types: intramuscular, subcutaneous, and surface EMG. Intramuscular EMG uses electrodes within muscle fibers, while subcutaneous EMG involves placing electrodes in the skin layer, which is less effective; surface EMG is the most commonly used and least invasive method. The document also discusses the relationship between EMG signals and muscle force, noting challenges with quantitative analysis due to electromechanical delays.

1. EMG

2. What is an EMG?
• An EMG (electromyography) is a method of
interpreting the potential difference between
two points in a muscle.

3. Types of EMG
• There are three types of EMG
• Intramuscular
• Subcutaneous
• Surface EMG

4. Intramuscular EMG
• An Intramuscular EMG is a method where the electrode is placed
within the muscle fibres using inter-dwelling electrodes
• Materials-
• Teflon insulated stainless steel biomechanical wire used by general
convention.
• Electrode placement-
• Silk suture used to separate electrodes by 5-7 mm to avoid cross-
talk.
• Placed in the mid belly region of a muscle

5. Subcutaneous
• A Subcutaneous EMG is the insertion of an
electrode into the subcutaneous layer between the
skin and muscle layer.
• The electrode by general convention is a stainless
steel needle.
• This method appears less effective as implied by the
reference source material when compared to the
other methods.

6. Surface EMG
• A surface EMG is an EMG using surface electrodes.
• It is the least invasive of the three types and most widely
used.
• Electrodes are placed on the mid belly region of the
muscle.
• Approximately 2 cm is needed between electrodes to
avoid cross-talk.

7. • Electrodes
•Differential Amplifier
•High and Low Pass Filters
•Precision Rectifiers

9. Differential Amplifier

10. High Pass Filter Low Pass Filter

11. Precision Rectifier

12. Our Model
• Version 1

13. Version 2
• The working model

15. EMG to Force
• There is a link between force and a spike in an EMG
signal.
• The precise quantitative nature is difficult to
calculate.
• Problems associated with this are
EMD(electromechanical delays) and the consistency
of the EMD throughout the EMG

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1
2 s
.344
.692
1.04
1.388
1.736
2.084
2.432
2.78
3.128
3.476
3.824
4.172
4.52
4.868
5.216
5.564
5.912
6.26
6.608
6.956
7.304
7.652
8.00
8.348
8.696
9.044
9.392
9.74
Y-Values
Y-Values
EMG SIGNAL ACCUIRED

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2.00
4.00
6.00
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Series 2
Series 3
ISOMETRIC SIGNAL