Science topic

Muscle Function - Science topic

Explore the latest questions and answers in Muscle Function, and find Muscle Function experts.
Questions related to Muscle Function
  • asked a question related to Muscle Function
Question
5 answers
Hello!
I am looking for resources to learn more about detailed muscle innervation related to its function. For example, the general knowledge about innervation for rectus abdominis is that it is innervated by intercostal nerve (T6-T11) and subcostal nerve (T12). I am looking for a bit deeper knowledge. For instance, would the innervation from the two different nerves into the rectus abdominis make different parts of the rectus abdominis function differently? Some people say lower and upper parts of the rectus abdominis should be assessed differently due to different fascial arrangement between these two parts. Are these two parts actually innervated differently? If so, I think this is quite a compelling and useful argument. It is not just about rectus abdominis. Similar arguments have been made for the hamstring groups. Some say that long head of the biceps femoris and short heads should be treated like two different muscles due to completely different innervation. I find such arguments fascinating and would love to learn more about the details.
Thank you so much for your time!
Relevant answer
Answer
Skeletal Muscle structure, function and plasticity by @RichardLieber
  • asked a question related to Muscle Function
Question
3 answers
I am a PhD student. The objective of my study is to explore the determinants of muscle function in Indian children. We got significant sex differences in the muscle function parameters hence we run 2 different regression models for boys and girls. However the reviewer has asked us to run a mediation moderation analysis to find out the interaction of gender. Please can anyone help me in guiding how to carry out this analysis?
Relevant answer
Answer
In order to test for moderated mediation, some recommend examining a series of models, sometimes called a piecemeal approach, and looking at the overall pattern of results. This approach is similar to the Baron and Kenny method for testing mediation by analyzing a series of three regressions.
  • asked a question related to Muscle Function
Question
1 answer
I intend to measure a muscle function on stroke patients and I read but with no supportive evidence that patients should stop having paracetamol or antibiotics month before the test because it may affect the outcome results.
Anybody has any idea or suggest evidence to support this notion
thanks
Relevant answer
Answer
Paracetamol is a dangerous drug, because is NOT an anti-inflammatory, and in a range normal usual doses, depleted more than 90% the Glutathione in liver, as you known, the more anti-oxidant system in the tissues. https://www.semanticscholar.org/paper/Paracetamol-and-Cardiac-Congenital-Malformations-in-Jara-Guerrero/68a3110cb81f625b9ce0cc3f3f9cfd0016aced88
  • asked a question related to Muscle Function
Question
17 answers
I am mostly thinking of children in the age above 6-7 years, who need something new.
Relevant answer
Answer
Regarding the outcome measure for older children, I had done a systematic review of outcome measures for torticollis, but only in infants. However I came across a few papers involving children. These three were looking at reference values for ROM in children: Argoblast et al 2007; Lewandowski & Szulc 2003; Lynch-Caris et al 2008. There are some authors who have looked at measuring abnormal head posture in ocular torticollis e.g. Hald 2011.
  • asked a question related to Muscle Function
Question
4 answers
We usually take the sample size from previous literature while working on muscle function assessment using some non-invasive technique like electromyography or mechanomyography. Any one knows about some statistical method to calculate the sample size in such studies?
Or is it adequate to follow the literature for this purpose?
Relevant answer
Answer
Dear Irsa,
I suggest to use G*power to do sample size calculations. http://www.gpower.hhu.de
It's a free software, relatively easy to use where you can take several design specifications into account. This is a scientifical way to calculate the sample size. Good luck and best regards
Erich
  • asked a question related to Muscle Function
Question
4 answers
Recently, i'd gone through an article of Clinical Biomechanics titled "Mechanomyography responses characterize altered muscle function during electrical stimulation-evoked cycling in individuals with spinal cord injury".
On page 24 (page 4 of the article), section 2.7 Data Analysis, line 3 to 7, it was mentioned "...were normalized to their respective peak values considering all the participants and trials....".
It seems the authors took the maximum value in the PRE condition from all the 6 subjects, and normalize the other data w.r.t that peak value. If someone can confirm whether the authors normalized each subject w.r.t that subject's peak value OR they took one peak value for all subjects and normalize all w.r.t that highest among all subjects peak value?
Is it really possible, i.e. to normalize w.r.t a single value for the whole experiment over different subjects?
Relevant answer
Answer
Thanks Dr. Ritzmann,
I'd gone through the document you mentioned above, I'd also seen few other articles on this very topic. It seems my understanding to the statement of the authors that i mentioned in the above question, is wrong. if you can please go through that document and comment on that particular statement.
  • asked a question related to Muscle Function
Question
1 answer
our bodies have many muscles and their functions,so what am curious about is that what does it take for a person to breadth a word.
Relevant answer
Answer
It is impossible to use only one muscle, there is always another muscle that must respond. If there is an external force involved, then the force must pass through the system and all muscles in the body would be involved. EMGs only reflect active muscle contraction, not isotonic use of muscles, so cannot tell muscle tension which is present in all muscles all the time,
(Masi, Alfonse T, and John Charles Hannon. "Human Resting Muscle Tone (HRMT): Narrative Introduction and Modern Concepts." Journal of bodywork and movement therapies 12, no. 4 (2008): doi:10.1016/j.jbmt.2008.05.007.). MOst two-joint muscles function as ligaments in closed kinematic chain. The short answer then would be, we use all our muscle all the time. As in fish jaws,
Hulsey, C D, and P C Wainwright. "Projecting Mechanics Into Morphospace: Disparity in the Feeding System of Labrid Fishes." Proceedings of the Royal Society of London. Series B: Biological Sciences 269, no. 1488 (2002): 317-326.), the muscles doing the contracting may be relatively remote from the apparent activity.
  • asked a question related to Muscle Function
Question
9 answers
I am analyzing EMG for squat lifting for 30 squats. The subjects were free to chose the squat speed. The rectus femoris muscle was under investigation. The activation pattern is not constant. And I want to find the Mean power frequency (MPF) for just the time the muscle is fully activated taking  a fixed window of 500 ms. I am using Megawin software and it has a setting of manually choosing area of interest for MPF calculation. I wanted to ask is it ok to use this method because if i chose a fixed interval for calculation of MPF for each squat, due to variation in timing it  misses the fully activated portion and instead calcualtes the MPF of rest period.   
Relevant answer
Answer
There are several muscle onset detection algorithms (Teager–Kaiser energy operator, fuzzy entropy etc.). You can use one of them to determine the first sample of your fixed window.
In my opinion, if you select your windows manually, your experiment will be less reproducible.
  • asked a question related to Muscle Function
Question
4 answers
We are increasingly concerned about the adverse effects of hospital imposed harm - specifically immobilisation in hospital beds or wards.  Finding the evidence base that confirms the adverse impact on physiology, function, mobility, independence or muscle function is vital.
Any papers that anyone can share would be widely appreciated.
Relevant answer
Answer
Research on mobility attached.
  • asked a question related to Muscle Function
Question
2 answers
In 2003 French data showed in a group of well nourished people, mean age 70 years, that CC < 31 cm was associated with low muscle function and not with lean body mass. (people were able to stand on one leg for the measurement)
Since the working definition of 2012 by EWGSOP, it is clear that CC does not equals with sarcopenia, but that is a factor besides muscle function (usual gait) and muscle power (hand grip).
BIA and DXA is not current available in acute geriatric wards.
Since muscle mass is an epidemiologic parameter, I wonder if research has been done, on the relation of CC en lean body mass in the west-european geriatric population, in order to implement this in clinical daily practice in Belgium.
kind regards,
dr Baeyens HIlde
az alma, Eeklo
Relevant answer
Answer
Chère amie,
A Toulouse, une publication de Rolland and coll de l'équipe de Bruno Vellas, pense que 31 cm est la réponse que vous me demandez.
A ma connaissanc, aucun autre papier ne donne une autre valeur
Bien à Vous
Jean-Pierre
  • asked a question related to Muscle Function
Question
3 answers
Settings and methods for EMG examination  of smooth muscle
Relevant answer
Answer
Peter,
I have many years of experience.  Can I help you?  RE Garfield
  • asked a question related to Muscle Function
Question
2 answers
Does anyone know if the same type of Musclefibers are decreased or is there a difference?
Relevant answer
Answer
The difference in muscle fiber type would depend upon the timing of the stroke (in utero, at birth or post natal).  The in utero or post birth may have the same issues of Fast IIb fiber loss, however the post natal children will vary based upon age as the older children will have developed an increase in fast muscle fibers and the appropriate neuromotor connectivity based upon their experiences prior to injury.  Fur
  • asked a question related to Muscle Function
Question
4 answers
when it comes about nerve supply of SCM and Trapezius, it was written that" since both are the derivatives of branchial arch so both are supplied by spinal accessory nerve."  but in embryology text book describing derivatives of branchial arch i donot find these muscles in the list. so i want clear picture about developmental source of these muscles and functional components of spinal accessory nerve.
thank you.
Relevant answer
Answer
thank you Emmanouil sir for useful answer. what i got from your answer is that in straight point, these two muscles are not the derivatives of sixth arch rather they derived from mesoderm lateral to 6th arch. on the basis of this fact i can assume that the functional component of 11th cranial nerve which supply these two muscles (spinal root of accessory nerve) should be general somatic efferent (GSE) not special visceral efferent (SVE). am i right sir?
  • asked a question related to Muscle Function
Question
7 answers
Mostly concerned with strength/muscle function. 
Relevant answer
Hi Sam,
I've attached an article to this message that might be of your interest. The study investigated the effects of a 24-week strength training program on body composition of elderly women. The paper was not written in English though. You may want to check the abstract. I hope it helps.
With best wishes,
Joao
  • asked a question related to Muscle Function
Question
3 answers
I need papers which deal with the topic muscle fatigue and CoM displacements. I would like to know what are the principal effects of muscle fatigue in the CoM displacements. However, I need of the most recent papers about this. 
Thanks.
Relevant answer
Answer
Hi Marcelo,
There is many reports out there. Here are some recent papers:
Age-Related Changes in Dynamic Postural Control and Attentional Demands are Minimally Affected by Local Muscle Fatigue http://www.ncbi.nlm.nih.gov/pubmed/26834626
Acute effects of muscle fatigue on anticipatory and reactive postural control in older individuals: a systematic review of the evidence http://www.ncbi.nlm.nih.gov/pubmed/24978932
Biomechanical reorganisation of stepping initiation during acute dorsiflexor fatigue http://www.ncbi.nlm.nih.gov/pubmed/21605984
Impact of ankle muscle fatigue and recovery on the anticipatory postural adjustments to externally initiated perturbations in dynamic postural control http://www.ncbi.nlm.nih.gov/pubmed/23111432
Those a few recent studies, and you can go from there to access many more.
Hope this helps. Norbert
  • asked a question related to Muscle Function
Question
4 answers
I'm looking for explanations from the points of view of  neurophysiology, neuropsychology, and related fields on the question of why people experience a sensation that is colloquially described as being “tense”. (My background is in computing science, dance, and somatic practice.) It seems to be such a simple question but I haven't really found an answer that satisfies me. The closest I've come to is Hanna's "sensory-motor amnesia" theory, which the rest of this post focuses on.
Here's what I understand so far: Anxiety is known to chronically activate muscles (Hazlett, McLeod, & Hoehn-Saric, 1994), and the feeling of tension is likely to be the phenomenological equivalent of this activation of the muscle tonus (though this needs a bit of elaboration). But what causes increased muscle activity? Why do our muscles “get tense” when we are stressed?
Repeatedly triggered physiological reflexes leads to chronic muscular tonus: Hanna's sensory-motor amnesia theory
In his books Somatics, Thomas Hanna asserts that “our sensory-motor systems continually respond to daily stresses and traumas with specific muscular reflexes” that when “repeatedly triggered create habitual muscular contractions which we cannot—voluntarily—relax” (1988, pp. xii–xiii). He calls this “habituated state of forgetfulness” sensory-motor amnesia (SMA).
He suggests three types of sensory motor responses that, when continuously triggered, lead to SMA: a “red light” reflex, a “green light” reflex, and the trauma reflex. The red light reflex is basically the mammalian startle response a withdrawal response that activates the a series of muscular reflexes. These include jaw contraction, eye blinking, brow contractions. activation of trapezius muscles to raise shoulders and bring head forward, flexion of the elbow, pronation of the lower arms, and abduction of the upper arms (Davis, 1984)The green light reflex is the Landau reflex (which primarily activates the extensor muscles) in babies. It is an assertive reflex that is “essential for the erect carriage of the body in standing and walking” (Hanna, 1988, p. 65). But, Hanna suggests, it can be triggered past the point when the reflex has served its purpose in babies and children, and instead is triggered all the way through adulthood: “Adults must make a living and be able to take care of themselves—whether they want to or not… The muscles of the back, [though] now totally mastered, are [still] being activated increasingly towards the responsibilities of life. The more responsible one is, the more often the back muscles are triggered.” (Hanna, 1988, p. 65)
Hanna only names three reflexes, although perhaps there are others that contribute to Hanna's theory of sensory-motor amnesia. For example, Bracha et al (2004) summarise human reactions to acute stress as “freeze, flight, fight, or fright”. Freezing is the state of hypervigilance, flight is characterised by an attempt to flee, fighting needs little elaboration, and fright is the state of tonic immobility. A fifth state, “faint” (flaccid immobility), can accompany acute fear or stress (Bracha, 2004; Gellhorn, 1965).
In general, the SMA theory seems to rest on two assumptions:
  1. Physical reflexes (whether they be the mammalian startle reflex, the Landau reflex, hypervigilance, tonic immobility, etc.) are activated (to some extent) in response to everyday situations that cause stress and anxiety.
  2. Repeated activation of these responses cause habitual muscular contractions, and these is what we feel and refer to in everyday terms as “tense muscles”.
My questions
  • How does sensory-motor amnesia theory fit with what is accepted in psychology and neuroscience?
  • If assumption 2) above is correct, is this related to “associative learning”?
  • What do you make of the suggestion that the Landau reflex—through its association with the development of more complex skills such as standing and walking—can then be further associated with other activities in which an individual is required to assert their presence in the world, such as taking on responsibilities in adult society?
  • Where else should I be looking or what keywords should I be using to find the answers to my questions? Any other comments or ideas?
Sorry for the length of the post. Thanks a bunch! 
References
  • Bracha, H. S. (2004). Freeze, Flight, Fight, Fright, Faint: Adaptationist Perspectives on the Acute Stress Response Spectrum. CNS Spectrums, 9(09), 679–685. http://doi.org/10.1017/S1092852900001954
  • Bracha, H. S., Ralston, T. C., Matsukawa, J. M., Williams, A. E., & Bracha, A. S. (2004). Does “fight or flight” need updating? Psychosomatics, 45(5), 448–449.
  • Davis, M. (1984). The Mammalian Startle Response. In R. C. Eaton (Ed.), Neural Mechanisms of Startle Behavior (pp. 287–352). Boston, MA: Springer US. Retrieved from http://link.springer.com/10.1007/978-1-4899-2286-1
  • Gellhorn, E. (1965). The Neurophysiological Basis of Anxiety: A Hypothesis. Perspectives in Biology and Medicine, 8(4), 488–515. http://doi.org/10.1353/pbm.1965.0058
  • Hanna, T. (1988). Somatics: reawakening the mind’s control of movement, flexibility, and health. Cambridge, MA: Da Capo Life Long.
  • Hazlett, R. L., McLeod, D. R., & Hoehn-Saric, R. (1994). Muscle tension in generalized anxiety disorder: Elevated muscle tonus or agitated movement? Psychophysiology, 31(2), 189–195. http://doi.org/10.1111/j.1469-8986.1994.tb01039.x 
Relevant answer
Answer
Hello Diego. You can check this papers for a actual point of view about the topic (Also the example of Gilles de la Tourette Syndrome):
-Larsman, P., Kadefors, R., & Sandsjö, L. (2013). Psychosocial work conditions, perceived stress, perceived muscular tension, and neck/shoulder symptoms among medical secretaries. International archives of occupational and environmental health, 86(1), 57-63.
-Nielson, K. A., Wulff, L. L., & Arentsen, T. J. (2014). Muscle tension induced after learning enhances long-term narrative and visual memory in healthy older adults. Neurobiology of learning and memory, 109, 144-150.
-Spencer, M. L. (2015). Muscle Tension Dysphonia: A Rationale for Symptomatic Subtypes, Expedited Treatment, and Increased Therapy Compliance. SIG 3 Perspectives on Voice and Voice Disorders, 25(1), 5-15.
-Burns, J. W., Gerhart, J. I., Bruehl, S., Peterson, K. M., Smith, D. A., Porter, L. S., ... & Keefe, F. J. (2015). Anger arousal and behavioral anger regulation in everyday life among patients with chronic low back pain: Relationships to patient pain and function. Health Psychology, 34(5), 547.
I hope this info be useful in some way to your work.
Bests, David 
  • asked a question related to Muscle Function
Question
5 answers
Are there some new reports about ATP contribution for extreme power contractions? I need to develop a model for predicting it and then which variables could be tested.
Relevant answer
Answer
During maximal intensity exercise, such as sprinting, ATP is re-synthesized from phosphocreatine and anaerobic glycolysis, while aerobic metabolism plays an important role as duration is increased and/or high intensity exercise bouts are repeated. Interestingly, the concentration of ATP never drops below 60-70% of the resting concentration, i.e. the ATP pool of the muscle is preserved, although in some muscle fibres, ATP may drop to zero (see refs below).This is dependent on fiber type. For furthter reading, please see the papers below
Bogdanis GC, Nevill ME, Boobis LH, Lakomy HK, Nevill AM. Recovery of power output and muscle metabolites following 30 s of maximal sprint cycling in man. J Physiol. 1995 Jan 15;482 ( Pt 2):467-80.
Bogdanis GC, Nevill ME, Lakomy HK, Boobis LH. Power output and muscle metabolism during and following recovery from 10 and 20 s of maximal sprint exercise in humans.Acta Physiol Scand. 1998 Jul;163(3):261-72.
Nevill AM, Jones DA, McIntyre D, Bogdanis GC, Nevill ME.A model for phosphocreatine resynthesis. J Appl Physiol (1985). 1997 Jan;82(1):329-35.
Bogdanis GC, Nevill ME, Boobis LH, Lakomy HK. Contribution of phosphocreatine and aerobic metabolism to energy supply during repeated sprint exercise. J Appl Physiol (1985). 1996 Mar;80(3):876-84.
Hellsten Y, Richter EA, Kiens B, Bangsbo J. AMP deamination and purine exchange in human skeletal muscle during and after intense exercise. J Physiol. 1999 Nov 1;520 Pt 3:909-20.
Söderlund K, Hultman E. ATP and phosphocreatine changes in single human muscle fibers after intense electrical stimulation. Am J Physiol. 1991 Dec;261(6 Pt 1):E737-41.
Gray SR, Söderlund K, Ferguson RA. ATP and phosphocreatine utilization in single human muscle fibres during the development of maximal power output at elevated muscle temperatures. J Sports Sci. 2008 May;26(7):701-7. doi: 10.1080/02640410701744438.
  • asked a question related to Muscle Function
Question
7 answers
Every year a lot of studies are published on tourniquet time and blood loss and outcome after TKA. I do not use a tourniquet at any time of the TKA procedure. I am interested in conducting a study to assess quad muscle function and outcome of TKA without using a tourniquet.
Relevant answer
Answer
Dear Rene Attal,
I think that article could be useful to you!
Harsten, A. 2015 Tourniquet versus no tourniquet on knee-extension strength early after fast-track total knee arthroplasty; a randomized controlled trial
Knee
Have a nice day!
Giacomo
  • asked a question related to Muscle Function
Question
8 answers
Hi
I have a question about forces component in pennate musles.
In pennate muscles, the forces produce in muscle fibers should transform into two component of horizontal and vertical. The vertical component acts in tendon direction and will shorten the length of pennate muscle. But what is the role of horizontal component? Is this force wasted? Does it do some specific task?
Relevant answer
Answer
This question is certainly at the forefront of the current state of dynamic in vivo imaging and our 3D models of complex muscle architecture.  All models are wrong, and some models are useful.  That Lieber guy should be commended for acting like a scientist and relying on data to increase our understanding.  Most scientist of his stature would pronounce their previous findings as the gospel.  
Often, these muscles wrap around a joint or bony structure, and their actions cause compressive, tensile or twisting deformations of their constrained space during shortening, further complicating models of force production.  It appears they may be a career's worth of research waiting here for someone.
  • asked a question related to Muscle Function
Question
5 answers
Ultra-structural damage including plasma membrane impairments and damage to the sarcoplasmic  reticulum have been observed following unaccustomed eccentric exercise (Warren et al., 1993 Friden et al., 1993., etc). My question is, is there any possibility that omega-3 fatty acids may play a role in maintaining plasma membrane integrity and the subsequent reduction in membrane permeability and Ca2+ concentration?
Relevant answer
Answer
Thank you very much for your answers! Highly appreciated. I am in the process of doing my literature review and I will be looking up some of your suggestions.
Kind regards,
Sallu
  • asked a question related to Muscle Function
Question
4 answers
What differentiates those that are able to cope with an ACL injury from those that aren't is unclear. Potential copers may be able to return to sports/ADLs following ACL injury, while non-copers may not always be capable. What do you think differentiates these two groups?
Relevant answer
Answer
Hamstring and quadriceps force, ratio, and rate of development are interesting, but to date have only been found to play a role in female athletes for prevention of ACL injury. At least that I'm aware of in the literature.
Currently, I think the best predictors are still hop tests, effusion, and global rating score for a quick in clinic assessment. However, return to sport must be done on a person by person basis depending on the individuals goals and likelihood for re-injury (graft type, age, body mass, are good predictors).
Tibial plateau geometry is interesting, but I have never had a patient that was interested in changing their bone shape to either avoid initial or secondary ACL injury. Therefore, this as a risk factor for possible interventions does not appear to be fruitful at this point.
Thoughts?