intramuscular emg quiz
DESCRIPTION
A presentation put together for my weekly lab meeting based on the recent publication "Analysis of intramuscular electromyogram signals" (pubmed: http://tinyurl.com/b4mryy).Concepts highlighted in the manuscript are reviewed with multiple choice questions mixed in between.TRANSCRIPT
![Page 1: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/1.jpg)
Analysis of intramuscular electromyogram signals
It's a quiz!
Dario FarinaRoberto Merletti
![Page 2: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/2.jpg)
Basmajian 1968
![Page 3: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/3.jpg)
What is the term given to describe all of the muscle fibers belonging to one motor unit?
1. Task group
2. Muscle unit
3. Fiber unit
4. Contractile apparatus
![Page 4: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/4.jpg)
What is the term given to describe all of the muscle fibers belonging to one motor unit?
1. Task group
2. Muscle unit
3. Fiber unit
4. Contractile apparatus
![Page 5: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/5.jpg)
Stålberg et al. 1995
Motor Unit 1
Stålberg et al. 1995Stålberg et al. 1995
Motor Unit 2
Motor Unit 3
![Page 6: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/6.jpg)
Volume conductor
![Page 7: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/7.jpg)
![Page 8: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/8.jpg)
![Page 9: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/9.jpg)
![Page 10: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/10.jpg)
![Page 11: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/11.jpg)
![Page 12: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/12.jpg)
Which needle electrode configuration is likely to produce the lower two traces?
1.
2.
3.
4.
Distance from AP
Sign
al a
mpl
itude
Detection volume
![Page 13: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/13.jpg)
Which needle electrode configuration is likely to produce the lower two traces?
1.
2.
3.
4.
Distance from AP
Sign
al a
mpl
itude
Detection volume
![Page 14: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/14.jpg)
All of the following are limitations of intramuscular recordings except:
1. Reflects the activity of only a small number of active motor units
2. The detected APs are not representative of all fibers belonging to the motor unit
3. Permits recording from deep muscles
4. It is difficult to have the same unit in repeated insertions
![Page 15: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/15.jpg)
All of the following are limitations of intramuscular recordings except:
1. Reflects the activity of only a small number of active motor units
2. The detected APs are not representative of all fibers belonging to the motor unit
3. Permits recording from deep muscles
4. It is difficult to have the same unit in repeated insertions
![Page 16: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/16.jpg)
27G needle = 0.41 mm
Muscle fiber = 50 μm
8.2 X
![Page 17: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/17.jpg)
![Page 18: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/18.jpg)
![Page 19: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/19.jpg)
![Page 20: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/20.jpg)
What is one limitation of wire electrodes compared with needle electrodes?
1. Cause less subject discomfort/pain during contraction
2. Ability to be repositioned (in & out of muscle)
3. More stability over long periods of time
4. More stability during movement
![Page 21: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/21.jpg)
What is one limitation of wire electrodes compared with needle electrodes?
1. Less subject discomfort/pain during contraction
2. Ability to be repositioned (in & out of muscle)
3. More stability over long periods of time
4. More stability during movement
![Page 22: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/22.jpg)
Gydikov et al. 1986
Wire 1
Wire 2
Site 1
Site 2a Site 2b
Signal = Wire 1 - Wire 2
![Page 23: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/23.jpg)
Which of the following would NOT improve the signal of the branched bipolar electrode?
1. Reducing the amount of insulation removed and distance between removal sites
2. Placing the electrode parallel to the muscle fibers
3. Closer positioning of the electrode to the muscle fascia
4. Repositioning of the electrode along the muscle belly
![Page 24: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/24.jpg)
Which of the following would NOT improve the signal of the branched bipolar electrode?
1. Reducing the amount of insulation removed and distance between removal sites
2. Placing the electrode parallel to the muscle fibers
3. Closer positioning of the electrode to the muscle fascia
4. Repositioning of the electrode along the muscle belly
![Page 25: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/25.jpg)
1) Triggering single fiber electrode
2) Exposed macroelectrode
Surface
Stålberg et al. 1980
![Page 26: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/26.jpg)
A macro EMG electrode can be used to address all but which of the following:
1. Is the size of motor units of older adults consistent with young adults?
2. Does a particular pathology involve the reinnervation of affected muscle fibers?
3. Are estimates of the number of motor units consistent across age and disease?
4. Does muscle fiber conduction velocity change during eccentric contractions?
![Page 27: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/27.jpg)
A macro EMG electrode can be used to address all but which of the following:
1. Is the size of motor units of older adults consistent with young adults?
2. Does a particular pathology involve the reinnervation of affected muscle fibers?
3. Are estimates of the number of motor units consistent across age and disease?
4. Does muscle fiber conduction velocity change during eccentric contractions?
![Page 28: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/28.jpg)
Example articles:
1. Masakado et al. 1994
2. Ivanyi et al. 1994
3. de Koning et al. 1988
![Page 29: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/29.jpg)
Stålberg & Antoni 1980
Muscle 1) Triggering SFEMG electrode
Investigated corridor
MU territory2) Concentric needle electrode
![Page 30: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/30.jpg)
Stålberg & Antoni 1980
20 increments
![Page 31: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/31.jpg)
What is the length of the MU cross section (mm) and how does this compare to the actual territory size?
1. 10, this is likely an overestimate
2. 1, this is likely an overestimate
3. 10, this is likely an underestimate
4. 1, this is likely an underestimate
![Page 32: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/32.jpg)
What is the length of the MU cross section (mm) and how does this compare to the actual territory size?
1. 10, this is likely an overestimate
2. 1, this is likely an overestimate
3. 10, this is likely an underestimate
4. 1, this is likely an underestimate
![Page 33: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/33.jpg)
What is decomposition?
1. Identification of motor units from an interference EMG signal
2. Classification of a motor unit type from EMG
3. Quantitative description of a motor unit action potential
4. Something best left to the EBIO department
![Page 34: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/34.jpg)
What is decomposition?
1. Identification of motor units from an interference EMG signal
2. Classification of a motor unit type from EMG
3. Quantitative description of a motor unit action potential
4. Something best left to the EBIO department
![Page 35: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/35.jpg)
Decomposition
![Page 36: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/36.jpg)
Put the steps of decomposition in the correct order:
1. Detection or segmentation – how does information differ from noise signal
2. Identification and classification of an “ideal” MUAP
3. Verification of Identified MUAP's
4. Recognition or Classification
![Page 37: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/37.jpg)
Put the steps of decomposition in the correct order:
1. Detection or segmentation – how does information differ from noise signal
2. Identification and classification of an “ideal” MUAP
3. Verification of Identified MUAP's
4. Recognition or Classification
1
2
3
4
![Page 38: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/38.jpg)
Put the steps of decomposition in the correct order:
1. Detection or segmentation – how does information differ from noise signal
2. Identification and classification of an “ideal” MUAP
3. Verification of Identified MUAP's
4. Recognition or Classification
−Generally 1 and 2 are combined in one step
1
2
3
4
![Page 39: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/39.jpg)
Identification of MUAP's
Peak to peak
Voltage
# of phases, turns
Duration
Fourier transformation coefficients
Coefficients from other transformations
Time sample of filtered signal
Wavelet characteristics
Merletti and Farina 2008
![Page 40: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/40.jpg)
Wavelet vs. Fourier Transform
Meyer Mexican Hat
![Page 41: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/41.jpg)
What is not a limitation to Decomposition?
1. No ideal waveform available
2. Must come from intramuscular EMG
3. Inaccurate past ~50% MVC
4. Can only readily identify 3-8 MU's
![Page 42: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/42.jpg)
What is not a limitation to Decomposition?
1. No ideal waveform available
2. Must come from intramuscular EMG
3. Inaccurate past ~50% MVC
4. Can only readily identify 3-8 MU's
![Page 43: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/43.jpg)
How are waves decomposed?
Peel off method Modeling method
http://www.ling.umd.edu/~idsardi/sinewave/
![Page 44: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/44.jpg)
MATLAB based EMGLAB resolved superimpositions with which method?
1. Modeling approach
2. “Best match” or “peel off” method
![Page 45: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/45.jpg)
MATLAB based EMGLAB resolved superimpositions with which method?
1. Modeling approach
2. “Best match” or “peel off” method
![Page 46: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/46.jpg)
MATLAB based EMGLAB resolved superimpositions with which method?
1. Modeling approach
2. “Best match” or “peel off” method
Which is more powerful? difficult?
![Page 47: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/47.jpg)
Stashuk 2001
Modelling vs. Peel Off
![Page 48: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/48.jpg)
Which is not a method of verifying a decomposed signal?
1. Comparison with ideal waveform characteristics
2. Cross verification from two different locations
3. Mathematical reference signal
4. Expert Operator verification
![Page 49: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/49.jpg)
Which is not a method of verifying a decomposed signal?
1. Comparison with ideal waveform characteristics
2. Cross verification from two different locations
3. Mathematical reference signal
4. Expert Operator verification
![Page 50: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/50.jpg)
Which is not true with regards to decomposition in a clinical setting?
1. Done using interference EMG signal
2. Uses same methodology as in research setting
3. Impractical for clinical use
4. True decomposition is beyond the realm of clinicians
![Page 51: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/51.jpg)
Which is not true with regards to decomposition in a clinical setting?
1. Done using interference EMG signal
2. Uses same methodology as in research setting
3. Impractical for clinical use
4. True decomposition is beyond the realm of clinicians
![Page 52: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/52.jpg)
First dorsalinterosseus
Amplifier(EMG)
Triggerunit
Averager
Amplifier
Surface electrodearray
Muscle fiberconduction
velocity
Farina et al. 2002
![Page 53: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/53.jpg)
If the time between averaged waveforms is 1.28 ms and the CV is 3.9 m*s-1, how far apart are
the electrodes on the array in mm?
1) 5
2) 0.39
3) 7.5
4) 0.5
![Page 54: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/54.jpg)
If the time between averaged waveforms is 1.28 ms and the CV is 3.9 m*s-1, how far apart are
the electrodes on the array in mm?
1) 5
2) 0.39
3) 7.5
4) 0.5
![Page 55: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/55.jpg)
First dorsalinterosseus
Amplifier(EMG)
Triggerunit
Amplifier
Averager
Forcetransducer
Torquecontribution
![Page 56: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/56.jpg)
Stålberg & Falck 1997
![Page 57: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/57.jpg)
Patient 1 Patient 2
Signal A Signal B
![Page 58: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/58.jpg)
Which detection system (intramuscular or surface) is used to diagnose pathologies and why?
1. Intramuscular, lower frequencies are preserved
2. Intramuscular, features of individual APs are preserved
3. Surface, you record from more fibers
4. Surface, the signal bandwidth allows for analysis of the number of turns in AP shape
![Page 59: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/59.jpg)
Which detection system (intramuscular or surface) is used to diagnose pathologies and why?
1. Intramuscular, lower frequencies are preserved
2. Intramuscular, features of individual APs are preserved
3. Surface, you record from more fibers
4. Surface, the signal bandwidth allows for analysis of the number of turns in AP shape
![Page 60: Intramuscular EMG Quiz](https://reader034.vdocuments.net/reader034/viewer/2022042502/54678076b4af9fda3f8b5461/html5/thumbnails/60.jpg)
References*Adrian & Bronk 1929
Basmajian 1963
Basmajian & Stecko 1962
Buchthal at el. 1957
de Koning et al. 1988
De Luca & Forrest 1972
Farina et al. 2002
Gydikov et al. 1986
Haig et al. 2003
Ivanyi et al. 1994
Masakado et al. 1994
Stålberg & Antoni 1980
Stålberg & Falck 1997
Stålberg et al. 1980
Stålberg et al. 1995
Stashuck 2001
*Click on each study to view record on journal website