The relationship between surface EMG (sEMG) and muscle force is complex, depending on factors like motor unit recruitment and firing rates, muscle fiber type composition, fatigue, and dynamic conditions. In general, sEMG amplitude and muscle force increase proportionally with recruitment and higher firing rates. However, the exact shape of the sEMG-force relationship can vary between linear and non-linear depending on the individual muscle and contraction conditions. Dynamic contractions and muscle fatigue can further impact this relationship. While sEMG can provide an estimate of relative muscle force, many factors must be considered for accurate quantification.
Basic MEP techniques and understanding for Intraoperative neuromonitoring of the motors tracts during Brain and Spinal surgeries to prevent postoperative complications.
Basic MEP techniques and understanding for Intraoperative neuromonitoring of the motors tracts during Brain and Spinal surgeries to prevent postoperative complications.
Important structures associated with neural control of locomotion- CPGs, Peripheral receptors and afferents, Basal ganglia, Cerebellum, Brainstem, Cerebellar Cortex.
Late response are the most helpful findings in some of the diseases affecting the peripheral nerves, (e.g GBS, Radiculopathies, ). How to assess these responses while performing Nerve Conduction Studies, is the most technical and theoretical consideration.... Here we go with the same things in the stated slides
Tender points are areas of the body that experience different types of pain when pressure is applied to them.
A Trigger Point (TrP) is a hyperirritable spot, a palpable nodule in the taut bands of the skeletal muscles' fascia.
Important structures associated with neural control of locomotion- CPGs, Peripheral receptors and afferents, Basal ganglia, Cerebellum, Brainstem, Cerebellar Cortex.
Late response are the most helpful findings in some of the diseases affecting the peripheral nerves, (e.g GBS, Radiculopathies, ). How to assess these responses while performing Nerve Conduction Studies, is the most technical and theoretical consideration.... Here we go with the same things in the stated slides
Tender points are areas of the body that experience different types of pain when pressure is applied to them.
A Trigger Point (TrP) is a hyperirritable spot, a palpable nodule in the taut bands of the skeletal muscles' fascia.
Samuel M. Theagene, MD, leads as founder and medical director of Empire State Pain and Neuro, PC, in New York. There, Dr. Samuel Theagene uses electromyography and other state-of-the-art technologies to diagnose and treat all types of chronic, acute, and subacute pain.
Central Park Physical Medicine - ElectromyographySamuel Theagene
As the medical director of Central Park Physical Medicine, PC, Dr. Samuel M. Theagene supervises pain management and patient care at the clinic, which the latest in medical technology, such as electromyography and fluoroscopy. Samuel M. Theagene, MD, has been a practicing pain specialist for over 20 years and is a board certified Interventional Pain Physician.
Emg (2) /certified fixed orthodontic courses by Indian dental academy Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Electromyograph slah satu alat kesehatan yang mendeteksi otot2 , baik dalam trisep atau bisep. alat ini mempunyai 2 elektroda sebagai penyadap sinyal - sinyal otot. Outpunya dapat berupa LCD..
The proposed EMG signals analysis relies on the frequency domain where features of healthy EMG signal and myopathic EMG signals are analyzed and compared. Methodology described the relationship between the EMG signals and the properties of a contracting & myopathic muscle by analysing its power density spectrum. Periodogram Mean-Square Spectrum Estimate (PMSSE) of EMG Signal and the Power spectral Density is calculated with Welch's PSD estimate method by taking Hamming & Kaiser Window for both the healthy & myopathic signals. The analysis can provide important clues to design feature extraction methods and the resulting information can be used to determine the origin of the weakness.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This power point presentation is presented by Satyajit Mohanty, MSPT,MIAP, MHPC(UK), a specialist physiotherapist in sports physiotherapists. This presentation till take you through the manual therapy prospective of lumbar spinal paraspinal EMG.
have a happy reading. Thank you.
Electromyography Analysis for Person IdentificationCSCJournals
Physiological descriptions of the electromyography signal and other literature say that when we make a motion, the motor neurons of respective muscle get activated and all the innervated motor units in that zone produce motor unit action potential. These motor unit action potentials travel through the muscle fibers with conduction velocity and superimposed signal gets recorded at the electrode site. Here we have taken an analogy from the speech production system model as the excitation signal travels through vocal tract to produce speech; similarly, an impulse train of firing rate frequency goes through the system with impulse response of motor unit action potentials and travels along the muscle fiber of that person. As the vocal tract contains the speaker information, we can also separate the muscle fiber pattern part and motor unit discharge pattern through proper selection of features and its classification to identify the respective person. Cepstral and non uniform filter bank features models the variation in the spectrum of the signals. Vector quantization and Gaussian mixture model are the two techniques of pattern matching have been applied.
Effect of Endurance on Gastrocnemius Muscle with Exercise by Employing EMG Am...ijtsrd
Muscle fatigue is a common experience in daily life. Many authors have defined it as the incapacity to maintain the required or expected force, and therefore, force, power and torque recordings have been used as direct measurements of muscle fatigue. In addition, the measurement of these variables combined with the measurement of surface electromyography sEMG recordings which can be measured during all types of movements during exercise may be useful to assess and understand muscle fatigue. EMG signal can be easily analyzed in time domain, frequency domain and time frequency domain. The time domain features are the most popular in EMG pattern recognition because they are easy and quick to calculate and they do not require a transformation. The purpose of this study was to analyze the fatigue and to study the endurance occurrence in the Gastrocnemius muscle with a pre defined exercise protocol for the targeted muscle. For this purpose, sEMG Amplitude parameters were characterized. Relation between EMG features like mean, force, standard deviation, etc. is verified for fatigue detection as well as to identify the Endurance developed in the Gastrocnemius muscle. Gaurav Patti | Poonam Kumari "Effect of Endurance on Gastrocnemius Muscle with Exercise by Employing EMG Amplitude Parameters" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-5 , August 2020, URL: https://www.ijtsrd.com/papers/ijtsrd33222.pdf Paper Url :https://www.ijtsrd.com/engineering/other/33222/effect-of-endurance-on-gastrocnemius-muscle-with-exercise-by-employing-emg-amplitude-parameters/gaurav-patti
Mechanics of the human hamstring muscles during sprintingFernando Farias
As peak musculotendon
force and strain for BF
LH
, ST, and SM occurred around the same time during terminal swing, it is suggested that this period in the
stride cycle may be when the biarticular hamstrings are at greatest injury risk. On this basis, hamstring injury prevention or rehabilitation
programs should preferentially target strengthening exercises that involve eccentric contractions performed with high loads at longer
musculotendon lengths.
Non-uniform electromyographic activity during fatigue and recovery of the vas...Nosrat hedayatpour
The aim of the study was to investigate EMG signal features
during fatigue and recovery at three locations of the vastus
medialis and lateralis muscles.
The presented approach is conceptually useful in
illustrating the alteration in motor units (MUs) for
neuromuscular disorders and discussed on the properties of
PDS & PSD of EMG signals. The proposed power spectral
density method comparatively analyzed the healthy &
neuropathy signals with Welch's PSD estimation method by
Hamming & Kaiser Window. The distributions of power over
frequency components for both the signals are significantly
compared. This analysis is intended to provide an automatic
diagnosis of an individual’s muscle condition.
Echogenicity: Implication of Rehabilitative Ultrasound Imaging for Assessing ...Zinat Ashnagar
The accumulation of connective and adipose tissues in the muscles may result in changes of muscle quality or composition. The computed tomography imaging serves as a gold standard for the assessment of muscle quality and shows reduced attenuation coefficient due to augmented fat infiltration. Muscle quality can also be assessed by using musculoskeletal ultrasound imaging.
Rehabilitative Ultrasound Imaging: A musculoskeletal PerspectiveZinat Ashnagar
This presentation provides basic introduction to Rehabilitative Ultrasound Imaging, and applications in rehabilitation. this presentation also review the applications of other imaging methods such as MRI & CT, and compare them to USI. It also review the other formats of ultrasound imaging such as Elastography and High-frame-rate USI. Finally the RUSI of Abdominal muscles reviewed here to provide an example of applications of RUSI.
Reaction time measures are common in many sport settings; an example is the interval between the starter’s gun and the first movement in a swimming race. Reaction time measures are also studied extensively in the laboratory as measures of information-processing speed.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
2. Can the surface EMG (sEMG) be
utilized to quantify the force developed
by a muscle at a given time?
EMG-Force Relationship
2
3. Force production in a muscle is regulated by two
main mechanisms:
Recruitment of additional MUs
the increase of firing rate of the already active
MUs.
(Merletti, ELECTROMYOGRAPHY Physiology, Engineering, and Noninvasive Applications,2004)
The amplitude of the surface EMG signal depends
on both the number of active MUs and their firing
rates.
EMG-Force Relationship
3
4. Since both EMG and force increase as a
consequence of the same mechanisms, it is
expected that muscle force can be estimated
from surface EMG analysis.
(Merletti, ELECTROMYOGRAPHY Physiology, Engineering, and Noninvasive
Applications,2004)
EMG-Force Relationship
4
5. The possibility of estimating muscle force from the
EMG signal is attractive as it allows the assessment
of the contributions of single muscles to the total
force exerted by a muscle group.
This is the main reason why EMG is and probably
always will be the method of choice for force
estimation in kinesiological studies.
(Merletti, ELECTROMYOGRAPHY Physiology, Engineering, and Noninvasive
Applications,2004)
EMG-Force Relationship
5
7. This figure (adopted & redrawn from 10, p. 110) shows the dependency of
the EMG/force ratio from angle position (A,B), which can be eliminated by
normalization of the MVC of force.
7
8. C. Disselhorst-Klug et al. Surface electromyography and muscle force: Limits in SEMG–force
relationship and new approaches for applications. Clinical Biomechanics 24 (2009) 225–235
EMG-Force Relationship
8
9. The force output of a single MU is regulated by its
firing rate.
The increase in force saturates at around 30–40
pulses per second, which is below the maximum
MU firing rate. (Enoka and Fuglevand,2001)
An increase in firing rate above the rate at which
MU force saturates is reflected in the EMG signal
and this will compromise accurate force estimation.
D. Staudenmann et al. Methodological aspects of SEMG recordings for force estimation – A tutorial
and review. Journal of Electromyography and Kinesiology 20 (2010) 375–387
EMG-Force Relationship
9
10. The force increase with firing rate has been
predicted by modeling to be less than proportional
(Fuglevand et al., 1993).
This also holds for the increase in EMG amplitude,
due to increasing phase cancellation with an
increasing firing rate (Keenan et al., 2005).
EMG-Force Relationship
10
11. De Luca CJ. THE USE OF SURFACE ELECTROMYOGRAPHY IN BIOMECHANICS: Delsys
Incorporated; 1993. p. 21
11
12. Since MUs as contractile elements act
largely in parallel, the second mechanism
to control muscle force is the recruitment
of additional MUs, occurs in an orderly
sequence from small to large MUs.
D. Staudenmann et al. Methodological aspects of SEMG recordings for force
estimation – A tutorial and review. Journal of Electromyography and
Kinesiology 20 (2010) 375–387
EMG-Force Relationship
12
13. Because of the size principle, the increase in force with
additional MU recruitment is predicted by modeling to be
more than proportional (Fuglevand et al., 1993).
While the rise in MU size with increasing force would
suggest a more than proportional increase in EMG amplitude
as well, this is not necessarily true as MUP amplitude also
depends on the distance between the MU and the electrode
(Roeleveld et al., 1997b).
EMG-Force Relationship
13
14. i)
If the newly recruited motor unit is located close to the
electrode, then the relative increase of the EMG signal will
be greater than the corresponding increase of the force
because the new MUAP will contribute more than an average
unit of energy to the EMG signal.
ii) If the newly recruited motor unit is located far away from the
electrode, then the force will increase, but the amplitude of
the EMG signal will not.
De Luca CJ. THE USE OF SURFACE ELECTROMYOGRAPHY IN BIOMECHANICS: Delsys
Incorporated; 1993. p. 20
EMG-Force Relationship
14
15. De Luca CJ. THE USE OF SURFACE ELECTROMYOGRAPHY IN BIOMECHANICS:
Delsys Incorporated; 1993. p. 21
EMG-Force Relationship
15
16. Differences between muscles appear to exist in the
range of force over which new MUs are
recruited, with some muscles having all MUs
recruited at 50% of MVC and others recruiting
new MUs up to 100% MVC (Lawrence and De Luca,
1983; Woods and Bigland-Ritchie, 1983).
EMG-Force Relationship
16
17. It is important to note here that studies on the
relationship between muscle force and EMG
amplitude with very few exceptions in human
experiments (Heckathorne and Childress, 1981; Inman and Ralston, 1952) and
animal experiments (Guimaraes et al., 1995; Herzog et al., 1998; Liu et al.,
1999) did not actually measure muscle force.
D. Staudenmann et al. Methodological aspects of SEMG recordings for force estimation – A
tutorial and review. Journal of Electromyography and Kinesiology 20 (2010) 375–387
EMG-Force Relationship
17
18. Instead, the net output of a series of
synergistic antagonistic muscle was
measured.
In addition, effects of gravity and effects
of joint stiffness are often ignored,
although these may be quite substantial
(Ridderikhoff et al., 2004).
EMG-Force Relationship
18
19. Shape of the relation between
EMG and muscle force
Linear
Non-Linear
sEMG & Force
19
20. Linear
•
•
•
•
•
Bigland and Lippold, 1954;
De Jong and Freund,1967;
DeVries, 1968;
Korner et al., 1984;
Milner-Brown and Stein, 1975
EMG-Force Relationship
20
21. Non-Linear
Alkner et al., 2000
De Luca, 1997
Komi and Buskirk, 1970
Potvin et al.,1996
Solomonow et al., 1986b
Vink et al., 1987
Zuniga and Simons,1969
EMG-Force Relationship
21
22. The shape of the relationship between firing rate and force
may be different from the shape of the relationship between
firing rate and EMG amplitude.
As a consequence, it may be clear that the relationship
between EMG and force is not necessarily (nor
physiologically, nor biophysically) linear.
It is dependent on the recruitment range and hence on muscle
fiber type composition.
D. Staudenmann et al. Methodological aspects of SEMG recordings for force estimation – A tutorial and
review. Journal of Electromyography and Kinesiology 20 (2010) 375–387
EMG-Force Relationship
22
23. This figure (redrawn from 2, p. 193) shows EMG/force ratios of 3 different
muscles for MVC normalized EMG and force output data.
23
24. The differences between the large and small
muscles may possibly reflect the differences in
the firing rates of the muscles (slow versus
fast), their recruitment properties (which fibers
recruit as a function of the strength of the
contraction) and other anatomical and electrical
considerations.
CRISWELL E. CRAM’S INTRODUCTION TO Surface Electromyography.
second ed: Jones and Bartlett Publishers; 2011. p. 30.
sEMG & Force
24
25. In general, muscles that consist of predominantly one
fiber type tend to have a more linear relationship
between force exerted and SEMG.
In muscles of a mixed fiber type (fast- and slowtwitch fibers), the relationship appears to be more
curvilinear, with the breaking point at
approximately 50% of maximum voluntary
contraction.
CRISWELL E. CRAM’S INTRODUCTION TO Surface Electromyography. second ed:
Jones and Bartlett Publishers; 2011. p. 30.
25
26. Both the force and the EMG amplitude are in most
circumstances nonlinearly related to the neural
drive.
Apparently both nonlinearities in the relation between
neural drive and EMG, on the one hand, and drive
and force, on the other hand, balance each other,
leading to an often close-to-linear relation between
EMG and force.
(Merletti, ELECTROMYOGRAPHY Physiology, Engineering, and Noninvasive
Applications,2004)
EMG-Force Relationship
26
27. The relationship (if any) between force and amplitude should
be adapted to the muscle condition, including muscle length
(joint angle), muscle temperature, fatigue, and so on.
In particular, under submaximal contractions, the fatigued
muscle generates EMG signals with larger amplitude
compared to the unfatigued condition, although maintaining
a constant force.
(Merletti, ELECTROMYOGRAPHY Physiology, Engineering, and Noninvasive
Applications,2004)
EMG-Force Relationship
27
28. Other Factors
The surface EMG amplitude depends strongly on the
electrode location.
For locations in which EMG amplitude is very
sensitive to small electrode displacements it is
expected that the relation between EMG and force
may be poorer than in other locations.
Farina, D., R. Merletti, M. Nazzaro, and I. Caruso, “Effect of joint angle on surface EMG
variables for the muscles of the leg and thigh,” IEEE Eng Med Biol Mag 20, 62–71 (2001).
EMG-Force Relationship
28
29. Considering an “optimal” electrode placement, the
relation between force and EMG may depend on
the subcutaneous fat layer thickness, the
inclination of the fibers with respect to the
detection system, the distribution of conduction
velocities of the active MUs, the interelectrode
distance, the spatial filter applied for EMG
recording, the presence of crosstalk, and the
degree of synchronization of the active MUs.
(Merletti, ELECTROMYOGRAPHY Physiology, Engineering, and Noninvasive
Applications,2004)
EMG-Force Relationship
29
31. The EMG-Force ratio can be used to determine the
neuromuscular (training) status of a muscle.
Within static contractions with constantly increasing
force output (ramping) well-trained muscles show a
clear right shift of the ratio, atrophic or very
untrained muscles show a left shift.
Trained muscles need less EMG for a given force
output than atrophic or fatigued muscles.
Reference: ABC of EMG – A Practical Introduction to Kinesiological Electromyography. page 43
EMG-Force Relationship
31
32. Schematic EMG/force relationship in ramp contractions. Depending on the muscle
condition and training status the ratio can alter. Trained muscles need less EMG for a
given force output than atrophic or fatigued muscles.
Reference: ABC of EMG – A Practical Introduction to Kinesiological Electromyography. page 43
32
33. Muscle dynamics
In an anisometric contraction, various mechanical,
physiological, anatomical and electrical modifications occur
throughout the contraction that affect, in substantial ways, the
relationship between the signal amplitude and the force
produced by the muscle.
De Luca CJ. THE USE OF SURFACE ELECTROMYOGRAPHY IN
BIOMECHANICS: Delsys Incorporated; 1993. p. 18
EMG-Force Relationship
33
34. For example, the force-length relationship of the
muscle fibers varies non-linearly, and the shapes
of the MUAPs which construct the EMG signal,
are altered because the relative position of the
electrode fixed on the surface of the skin changes
with respect to the contracting muscle fibers.
De Luca CJ. THE USE OF SURFACE ELECTROMYOGRAPHY IN
BIOMECHANICS: Delsys Incorporated; 1993. p. 20
EMG-Force Relationship
34
35. If it is absolutely necessary to process an EMG signal detected
during an anisometric contraction, then make every attempt
to limit the analysis to a near-isometric epoch of the record
and extrapolate the interpretation of the analysis based on the
results from this epoch.
If the anisometric contractions are repetitive, such as those
found in gait and cycling, then choose for analysis a fixed
epoch in the period of the contraction. Make all comparisons
in this epoch.
De Luca CJ. THE USE OF SURFACE ELECTROMYOGRAPHY IN
BIOMECHANICS: Delsys Incorporated; 1993. p. 19
EMG-Force Relationship
35
36. In dynamic contractions, muscle force, at a given
neural drive and hence at a given EMG amplitude,
depends on muscle length and contraction
velocity (Blix, 1894; Hill,1997)
EMG-Force Relationship
36
38. Force–Velocity Relationships
Source: Reprinted from G. Soderberg, Selected Topics in Surface
Electromyography for Use in the Occupational Setting: Expert Perspective.
DHHS (NIOSH), Publication No. 91-100, Washington DC, NIOSH, 1992.
38
39. The SEMG–force relationship is different in
concentric versus eccentric contractions of a muscle.
(Komi and Buskirk, 1972; Linnamo et al., 2006)
While at the same force value EMG activity is
increased in concentric contraction compared to
static isometric contraction, it is lower in eccentric
contraction.
C. Disselhorst-Klug et al. Surface electromyography and muscle force: Limits in sEMG–force
relationship and new approaches for applications. Clinical Biomechanics 24 (2009) 225–235
39
40. Differences in Concentric Vs. Eccentric contractions
EMG amplitudes are generally less during negative
(eccentric) work vs. positive (concentric) work
(Komi, 1973; Komi et al., 1987)
– Preloaded tension in tendons (non-contractile
elements) requires less contribution from muscle
(contractile elements)
EMG-Force Relationship
40