What you will learn
EMG is a powerful technique used to record the electrical activity of muscles. It is a useful tool in the diagnosis and treatment of many medical conditions, including muscle disorders, nerve damage, and spinal cord injuries. This webpage aims to provide a comprehensive introduction to EMG and its applications in the medical field.
EMG devices are used to measure the electrical activity of muscles. There are two types of devices: surface EMG and needle EMG. Surface EMG is non-invasive and involves placing electrodes on the surface of the skin over the muscle being measured. Needle EMG is more invasive and involves inserting a needle electrode into the muscle being measured. The type of EMG device used depends on the specific application.
Figure shows Clarity EMG Octopus
Figure shows a The Dantec Keypoint Focus EMG
Figure shows a BC Group PS-2010
When are they used?
EMG (electromyography) devices are used to measure and record the electrical activity produced by skeletal muscles. EMG devices can be used in a variety of applications, including:
- Clinical diagnosis: EMG can be used to diagnose conditions such as muscle disorders, nerve damage, and motor neuron diseases.
- Physical therapy: EMG can be used to assess muscle function and to design exercise programs for individuals undergoing physical therapy.
- Prosthetics: EMG can be used to control prosthetic limbs or assistive devices by detecting the electrical signals generated by the muscles.
- Sports science: EMG can be used to analyze muscle activity during exercise and sports performance, which can help improve training programs and prevent injury.
- Research: EMG can be used in research studies to investigate muscle function and movement patterns in various contexts, such as biomechanics, ergonomics, and motor control.
Overall, EMG devices are useful in any situation where it is necessary to measure and analyze muscle activity.
How does electromyography(EMG) work?
The electronics of an EMG device work by measuring the electrical signals generated by muscle activity and amplifying them for analysis.
The EMG device typically consists of a set of electrodes that are attached to the skin overlying the muscle being studied. The electrodes detect the electrical signals produced by the muscle fibers as they contract and relax. These signals are then transmitted to an amplifier, which increases the amplitude of the signals to make them easier to detect and analyze.
After amplification, the signals are typically filtered to remove any unwanted noise or interference. This is done using a band-pass filter, which allows only signals within a specific frequency range to pass through.
The filtered signals are then digitized by an analog-to-digital converter (ADC), which converts the continuous analog signals into digital data that can be analyzed using a computer or other digital device.
Finally, the digital data is analyzed to determine characteristics of the muscle activity, such as its amplitude, duration, and frequency. This analysis can provide valuable information about muscle function and can be used to diagnose and treat a variety of muscle-related conditions.
Electromyography Controller from HTM Workshop
You can view a demo of how our EMG controller can be used to measure your muscle electrical activity and control a video game. Our EMG controller can also be customized to work with other games and applications,
How to use the EMG Software
Use our training video to learn more about how the EMG Software works
How to use the EMG Hardware
As you connect yourself to the EMG controller make sure you
1. Connect the EMG controller to your computer via the USB connector
2. Connect yourself to the EMG controller using the 3mm input jack – make sure to push the connector all the way in
3. You can adjust the EMG controller sensitivity using the potentiometer. Clockwise reduces the sensitivity and counterclockwise increases the sensitivity.
Testing the EMG Controller
If you want to examine the electrical signal of your EMG controller we recommend using an oscilloscope and measuring the signal at the designated test points on the board: TP1, TP2, TP3, and TP4. These test points are labeled on your controller.
Tips and Troubleshooting
Common issues/mistakes include:
- Windows 11 display issue – EMG software text appears small. Right click on the software, select properties, compatibility, and remove high DPI scaling.
- Software does not find any devices. First make sure to plug in your EMG device to a working USB port. Next verify that your computer detect the device – you may need to download the Arduino nano driver for FTDI chips
- Too sensitive or not sensitive enough to muscle activity – there is a potentiometer on the PCB board turn the potentiometer clockwise to reduce sensitivity or turn it counterclockwise to increase sensitivity.
- Device is connected, software loads, but when the program runs only noise is visible in the graph. Make sure the ECG lead cable is correctly attached the EMG controller.
Here are some examples of ways to challenge yourself even further with this device
- Attempt to use two EMG controllers on the same computer to control different keys inputs
- Compare the EMG output of different muscles in the body
- Measure the gain of the amplifier
Answer these questions to check your understanding and explore new topics
- What is the difference between surface EMG and intramuscular EMG, and how does this affect the information that can be gathered from EMG devices?
- How do EMG devices differentiate between signals from different muscles in the body, and what types of processing are used to extract useful information from these signals?
- What factors can affect the accuracy and reliability of EMG measurements, and how can these be minimized or controlled for in experimental designs?
- How do EMG devices interface with other types of physiological measurement tools, such as ECG monitors or EEG devices, and what types of data can be combined to gain a more complete understanding of the body’s function?
- What are some of the challenges associated with using EMG devices in clinical settings, and how can these be addressed to ensure that EMG measurements are accurate and useful for diagnosing and treating patients?
- How do EMG devices and their associated software systems evolve over time, and what are some of the latest innovations in this field that are pushing the boundaries of what we can learn about the human body through EMG measurements?
Show off your work with the EMG Controller by sharing your adventures on social media – make sure to tag us on posts with #HTMWorkshop.