Academic literature on the topic 'Muscle reflex activity'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Muscle reflex activity.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Muscle reflex activity"
1
Hoogkamer, Wouter, Frank Van Calenbergh, Stephan P. Swinnen, and Jacques Duysens. "Cutaneous reflex modulation and self-induced reflex attenuation in cerebellar patients." Journal of Neurophysiology 113, no. 3 (February 1, 2015): 915–24. http://dx.doi.org/10.1152/jn.00381.2014.
Full textAbstract:
Modulation of cutaneous reflexes is important in the neural control of walking, yet knowledge about underlying neural pathways is still incomplete. Recent studies have suggested that the cerebellum is involved. Here we evaluated the possible roles of the cerebellum in cutaneous reflex modulation and in attenuation of self-induced reflexes. First we checked whether leg muscle activity during walking was similar in patients with focal cerebellar lesions and in healthy control subjects. We then recorded cutaneous reflex activity in leg muscles during walking. Additionally, we compared reflexes after standard (computer triggered) stimuli with reflexes after self-induced stimuli for both groups. Biceps femoris and gastrocnemius medialis muscle activity was increased in the patient group compared with the control subjects, suggesting a coactivation strategy to reduce instability of gait. Cutaneous reflex modulation was similar between healthy control subjects and cerebellar patients, but the latter appeared less able to attenuate reflexes to self-induced stimuli. This suggests that the cerebellum is not primarily involved in cutaneous reflex modulation but that it could act in attenuation of self-induced reflex responses. The latter role in locomotion would be consistent with the common view that the cerebellum predicts sensory consequences of movement.
2
Gandevia, S. C., S. Miller, A. M. Aniss, and D. Burke. "Reflex influences on muscle spindle activity in relaxed human leg muscles." Journal of Neurophysiology 56, no. 1 (July 1, 1986): 159–70. http://dx.doi.org/10.1152/jn.1986.56.1.159.
Full textAbstract:
The study was designed to determine whether low-threshold cutaneous and muscle afferents from the foot reflexly activate gamma-motoneurons innervating relaxed muscles of the leg. In 15 experiments multiunit recordings were made from 21 nerve fascicles innervating triceps surae or tibialis anterior. In a further nine experiments the activity of 19 identified single muscle spindle afferents was recorded, 13 from triceps surae, 5 from tibialis anterior, and 1 from extensor digitorum longus. Trains of electrical stimuli (5 stimuli, 300 Hz) were delivered to the sural nerve at the ankle (intensity, twice sensory threshold) and the posterior tibial nerve at the ankle (intensity, 1.1 times motor threshold for the small muscles of the foot). In addition, a tap on the appropriate tendon at varying times after the stimuli was used to assess the dynamic responsiveness of the afferents under study. The conditioning electrical stimuli did not change the discharge of single spindle afferents. Recordings of rectified and averaged multiunit activity also revealed no change in the overall level of background neural activity following the electrical stimuli. The afferent responses to tendon taps did not differ significantly whether or not they were preceded by stimulation of the sural or posterior tibial nerves. These results suggest that low-threshold afferents from the foot do not produce significant activation of fusimotor neurons in relaxed leg muscles, at least as judged by their ability to alter the discharge of muscle spindle afferents. As there may be no effective background activity in fusimotor neurons innervating relaxed human muscles, it is possible that these inputs from the foot could influence the fusimotor system during voluntary contractions when the fusimotor neurons have been brought to firing threshold. In one subject trains of stimuli were delivered to the posterior tibial nerve at painful levels (30 times motor threshold). They produced an acceleration of the discharge of a spindle in soleus at a latency of approximately 125 ms, in advance of detectable activity in skeletomotor neurons and before an increase in muscle length was noted. It presumably resulted from activation of gamma-motoneurons innervating soleus by small myelinated afferents (A-delta range).
3
Avela, Janne, Heikki Kyröläinen, and Paavo V. Komi. "Altered reflex sensitivity after repeated and prolonged passive muscle stretching." Journal of Applied Physiology 86, no. 4 (April 1, 1999): 1283–91. http://dx.doi.org/10.1152/jappl.1999.86.4.1283.
Full textAbstract:
Experiments were carried out to test the effect of prolonged and repeated passive stretching (RPS) of the triceps surae muscle on reflex sensitivity. The results demonstrated a clear deterioration of muscle function immediately after RPS. Maximal voluntary contraction, average electromyographic activity of the gastrocnemius and soleus muscles, and zero crossing rate of the soleus muscle (recorded from 50% maximal voluntary contraction) decreased on average by 23.2, 19.9, 16.5, and 12.2%, respectively. These changes were associated with a clear immediate reduction in the reflex sensitivity; stretch reflex peak-to-peak amplitude decreased by 84.8%, and the ratio of the electrically induced maximal Hoffmann reflex to the maximal mass compound action potential decreased by 43.8%. Interestingly, a significant ( P < 0.01) reduction in the stretch-resisting force of the measured muscles was observed. Serum creatine kinase activity stayed unaltered. This study presents evidence that the mechanism that decreases the sensitivity of short-latency reflexes can be activated because of RPS. The origin of this system seems to be a reduction in the activity of the large-diameter afferents, resulting from the reduced sensitivity of the muscle spindles to repeated stretch.
4
Cidem, Muharrem, Ilhan Karacan, Halil Ibrahim Cakar, Mehmet Cidem, Oguz Sebik, Gizem Yilmaz, Kemal Sitki Turker, and Safak Sahir Karamehmetoglu. "Vibration parameters affecting vibration-induced reflex muscle activity." Somatosensory & Motor Research 34, no. 1 (January 2, 2017): 47–51. http://dx.doi.org/10.1080/08990220.2017.1281115.
Full text
5
Aminoff, Michael J., Douglas S. Goodin, and Rosemary S. Chequer. "FUNCTIONAL ROLES OF THE LATE REFLEX MUSCLE ACTIVITY." Journal of Clinical Neurophysiology 10, no. 2 (April 1993): 240. http://dx.doi.org/10.1097/00004691-199304000-00014.
Full text
6
Windhorst, Uwe, Thomas M. Hamm, and Douglas G. Stuart. "On the function of muscle and reflex partitioning." Behavioral and Brain Sciences 12, no. 4 (December 1989): 629–45. http://dx.doi.org/10.1017/s0140525x00024985.
Full textAbstract:
AbstractStudies have shown that in the mammalian neuromuscular system stretch reflexes are localized within individual muscles. Neuromuscular compartmentalization, the partitioning of sensory output from muscles, and the partitioning of segmental pathways to motor nuclei have also been demonstrated. This evidence indicates that individual motor nuclei and the muscles they innervate are not homogeneous functional units. An analysis of the functional significance of reflex localization and partitioning suggests that segmental control mechanisms are based on subdivisions of motor nuclei–muscle complexes. A partitioned organization of segmental control mechanisms could utilize (1) the potential functional diversity of muscle fiber types, (2) the variety of mechanical actions of individual muscles arising from their distributed origins and insertions, and (3) diverse architectural features such as intramuscular variations in pinnation and complex in-series and in-parallel arrangements of muscle fibers. The differentiated activity observed in some muscles during natural movements also calls for localized segmental control mechanisms. Partitioning may also play a role in mechanical interactions between contracting motor units and in increasing the stability of neuromuscular systems. The functional advantages of reflex localization and partitioning suggest they are probably common features of segmental systems, whose organization reflects the structure and function of their associated neuromuscular systems.
7
Oliven, A., M. Haxhiu, and S. G. Kelsen. "Reflex effect of esophageal distension on respiratory muscle activity and pressure." Journal of Applied Physiology 66, no. 2 (February 1, 1989): 536–41. http://dx.doi.org/10.1152/jappl.1989.66.2.536.
Full textAbstract:
The electrical activity of the respiratory skeletal muscles is altered in response to reflexes originating in the gastrointestinal tract. The present study evaluated the reflex effects of esophageal distension (ED) on the distribution of motor activity to both inspiratory and expiratory muscles of the rib cage and abdomen and the resultant changes in thoracic and abdominal pressure during breathing. Studies were performed in 21 anesthetized spontaneously breathing dogs. ED was produced by inflating a balloon in the distal esophagus. ED decreased the activity of the costal and crural diaphragm and external intercostals and abolished all preexisting electrical activity in the expiratory muscles of the abdominal wall. On the other hand, ED increased the activity of the parasternal intercostals and expiratory muscles located in the rib cage (i.e., triangularis sterni and internal intercostal). All effects of ED were graded, with increasing distension exerting greater effects, and were eliminated by vagotomy. The effect of increases in chemical drive and lung inflation reflex activity on the response to ED was examined by performing ED while animals breathed either 6.5% CO2 or against graded levels of positive end-expiratory pressure (PEEP), respectively. Changes in respiratory muscle electrical activity induced by ED were similar (during 6.5% CO2 and PEEP) to those observed under control conditions. We conclude that activation of mechanoreceptors in the esophagus reflexly alters the distribution of motor activity to the respiratory muscles, inhibiting the muscles surrounding the abdominal cavity and augmenting the parasternals and expiratory muscles of the chest wall.
8
Yu, J., Y. Wang, G. Soukhova, L. C. Collins, and J. C. Falcone. "Excitatory lung reflex may stress inspiratory muscle by suppressing expiratory muscle activity." Journal of Applied Physiology 90, no. 3 (March 1, 2001): 857–64. http://dx.doi.org/10.1152/jappl.2001.90.3.857.
Full textAbstract:
Recently, a vagally mediated excitatory lung reflex (ELR) causing neural hyperpnea and tachypnea was identified. Because ventilation is regulated through both inspiratory and expiratory processes, we investigated the effects of the ELR on these two processes simultaneously. In anesthetized, open-chest, and artificially ventilated rabbits, we recorded phrenic nerve activity and abdominal muscle activity to assess the breathing pattern when the ELR was evoked by directly injecting hypertonic saline (8.1%, 0.1 ml) into lung parenchyma. Activation of the ELR stimulated inspiratory activity, which was exhibited by increasing amplitude, burst rate, and duty cycle of the phrenic activity (by 22 ± 4, 33 ± 9, and 57 ± 11%, respectively; n = 13; P < 0.001), but suppressed expiratory muscle activity. The expiratory muscle became silent in most cases. On average, the amplitude of expiratory muscle activity decreased by 88 ± 5% ( P < 0.002). The suppression reached the peak at 6.9 ± 1 s and lasted for 200 s (median). Injection of H2O2 into the lung parenchyma produced similar responses. By suppressing expiration, the ELR produces a shift in the workload from expiratory muscle to inspiratory muscle. Therefore, we conclude that the ELR may contribute to inspiratory muscle fatigue, not only by directly increasing the inspiratory activity but also by suppressing expiratory activity.
9
Luu, Billy L., Rachel A. McBain, Janet L. Taylor, Simon C. Gandevia, and Jane E. Butler. "Reflex response to airway occlusion in human inspiratory muscles when recruited for breathing and posture." Journal of Applied Physiology 126, no. 1 (January 1, 2019): 132–40. http://dx.doi.org/10.1152/japplphysiol.00841.2018.
Full textAbstract:
Briefly occluding the airway during inspiration produces a short-latency reflex inhibition in human inspiratory muscles. This occlusion reflex seems specific to respiratory muscles; however, it is not known whether the reflex inhibition has a uniform effect across a motoneuron pool when a muscle is recruited concurrently for breathing and posture. In this study, participants were seated and breathed through a mouthpiece that occluded inspiratory airflow for 250 ms at a volume threshold of 0.2 liters. The reflex response was measured in the scalene and sternocleidomastoid muscles during 1) a control condition with the head supported in space and the muscles recruited for breathing only, 2) a postural condition with the head unsupported and the neck flexors recruited for both breathing and to maintain head posture, and 3) a large-breath condition with the head supported and the volume threshold raised to between 0.8 and 1.0 liters to increase inspiratory muscle activity. When normalized to its preocclusion mean, the reflex response in the scalene muscles was not significantly different between the large-breath and control conditions, whereas concomitant recruitment of these muscles for posture control reduced the reflex response by half compared with the control condition. A reflex response occurred in sternocleidomastoid when it contracted phasically as an accessory muscle for inspiration during the large-breath condition. These results indicate that the occlusion reflex does not produce a uniform effect across the motoneuron pool and that afferent inputs for this reflex most likely act via intersegmental networks of premotoneurons rather than at a motoneuronal level. NEW & NOTEWORTHY In this study, we investigated the effect of nonrespiratory activity on the reflex response to brief sudden airway occlusions in human inspiratory muscles. We show that the reflex inhibition in the scalene muscles was not uniform across the motoneuron pool when the muscle was recruited concurrently for breathing and postural control. The reflex had a larger effect on respiratory-driven motoneurons than those recruited to maintain head posture.
10
Gregory, J. E., A. K. Wise, S. A. Wood, A. Prochazka, and U. Proske. "Muscle history, fusimotor activity and the human stretch reflex." Journal of Physiology 513, no. 3 (December 1998): 927–34. http://dx.doi.org/10.1111/j.1469-7793.1998.927ba.x.
Full textDissertations / Theses on the topic "Muscle reflex activity"
1
Pickup, C. M. "Studies on the reflex responses to joint displacement and muscle vibration in man." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376941.
Full text
2
Merkle, Shannon L. M. "Exploring pain & movement relationships: is greater physical activity associated with reduced pain sensitivity & does endogenous muscle pain alter protective reflexes in the upper extremity?" Diss., University of Iowa, 2016. https://ir.uiowa.edu/etd/2245.
Full textAbstract:
Pain and movement are intimately connected and nearly universal human experiences. However, our understanding of the extent, significance, and mechanisms of pain-movement relationships is limited. While pain is a normal, protective response to injury and potentially harmful stimuli, prolonged or dysfunctional neuromuscular adaptions in response to pain can contribute to a variety of pain conditions. Alternatively, movement (in the form of global physical activity, individual exercise programs, and/or specific motor learning/functional tasks) is often prescribed to help decrease pain and improve function. While attempts have been made to show an effect of movement on pain or to better understand altered movement strategies in response to pain, much of the research has been limited to animal models or to those with specific persistent or chronic pain conditions limiting generalizability and interpretability. Therefore, this research sought to advance current understanding of the relationships between physical activity and normal variability in centrally- and peripherally-mediated pain in healthy adults. Additionally, we sought to characterize changes in reflexive motor responses in the upper extremity to an endogenous, naturally-occurring, long-lasting acute muscle pain.
The results of these investigations indicate that greater, self-reported intense (i.e. vigorous) and leisure activity are more strongly associated with decreased pain sensitivity than is pain modulation or measured activity (via accelerometry). Future research is needed to determine directionality of these relationships. Further, reflexive motor responses to endogenous, acute muscle pain in the upper extremity were not significantly altered indicating that changes in pain-related, movement strategies may be more strongly influenced by supraspinal adaptations. These results may have value in improving understanding of pain-related, movement sequelae and directing future research in this area.
3
Cai, Bonnie Bao Yan. "Sex-related differences in the suppressive effects of peripheral morphine but not GABA on reflex jaw muscle activity evoked by glutamate application to the TMJ region in rats." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58880.pdf.
Full text
4
Basnayake, Shanika Deshani. "Identifying neurocircuitry controlling cardiovascular function in humans : implications for exercise control." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:a61a482a-f861-4dcd-b0c5-47f50290c9d9.
Full textAbstract:
This thesis is concerned with the neurocircuitry that underpins the cardiovascular response to exercise, which has thus far remained incompletely understood. Small animal studies have provided clues, but with the advent of functional neurosurgery, it has now been made possible to translate these findings to humans. Chapter One reviews the background to the studies in this thesis. Our current understanding of the cardiovascular response to exercise is considered, followed by a discussion on the anatomy and function of various brain nuclei. In particular, the rationale for targeting the periaqueductal grey (PAG) and the subthalamic nucleus (STN) is reviewed. Chapter Two reviews the use of deep brain stimulation (DBS), in which deep brain stimulating electrodes are implanted into various brain nuclei in humans, in order to treat chronic pain and movement disorders. This technique not only permits direct electrical stimulation of the human brain, but also gives the opportunity to record the neural activity from different brain regions during a variety of cardiovascular experiments. This chapter also gives a detailed methodological description of the experimental techniques performed in the studies in this thesis. Chapter Three identifies the cardiovascular neurocircuitry involved in the exercise pressor reflex in humans using functional neurosurgery. It shows for the first time in humans that the exercise pressor reflex is associated with significantly increased neural activity in the dorsal PAG. The other sites investigated, which had previously been identified as cardiovascular active in both animals and humans, seem not to have a role in the integration of this reflex. Chapter Four investigates whether changes in exercise intensity affect the neurocircuitry involved in the exercise pressor reflex. It demonstrates that the neural activity in the PAG is graded to increases in exercise intensity and corresponding increases in arterial blood pressure. This chapter also provides evidence to suggest that neural activity in the STN corresponds to the cardiovascular changes evoked by the remote ischaemic preconditioning stimulus in humans. Chapter Five identifies the cardiovascular neurocircuitry involved during changes in central command during isometric exercise at constant muscle tension using muscle vibration. It shows that, in humans, central command is associated with significantly decreased neural activity in the STN. Furthermore, the STN is graded to the perception of the exercise task, i.e. the degree of central command. The other sites investigated appear not to have as significant a role in the integration of central command during the light exercise task that was undertaken. Chapter Six studies the changes in muscle sympathetic nerve activity (MSNA) during stimulation of various brain nuclei in humans. Regrettably, the results presented in this chapter are not convincing enough to support the hypothesis that stimulation of particular subcortical structures corresponds to changes in MSNA. However, the cardiovascular changes that were recorded during stimulation of the different subcortical structures are congruous with previous studies in both animals and humans. Chapter Seven presents a brief summary of the findings in this thesis.
5
Hesketh, Kathryn Louise. "Behaviour of H- and cutaneous reflexes at different levels of background muscle activity." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ59816.pdf.
Full text
6
Le, Bozec Serge. "aspects et bases de la synergie des muscles agonistes chez l'Homme." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37599038x.
Full text
7
Lienhard, Karin. "Effet de l'exercice physique par vibration du corps entier sur l'activité musculaire des membres inférieurs : approche méthodologique et applications pratiques." Thesis, Nice, 2014. http://www.theses.fr/2014NICE4080/document.
Full textAbstract:
L’objectif de cette thèse a été d’analyser l’effet de l’exercice physique réalisé sur plateforme vibrante (whole-body vibration, WBV) sur l’activité musculaire des membres inférieurs, de développer des outils d’analyse méthodologiques et de proposer des recommandations pratiques d’utilisation. Deux études méthodologiques ont été menées pour identifier la méthode optimale permettant de traiter les signaux d'électromyographie de surface (sEMG) recueillis pendant la vibration et d'analyser l'influence de la méthode de normalisation de l'activité sEMG. Une troisième étude visait à mieux comprendre si les pics sEMG observés dans le spectre de puissance du signal contiennent des artéfacts de mouvement et/ou de l'activité musculaire réflexe. Les trois études suivantes avaient pour but de quantifier l’effet de la WBV sur l’activité musculaire en fonction de différents paramètres tels que, la fréquence de vibration, l'amplitude de la plateforme, une charge supplémentaire, le type de plateforme, l'angle articulaire du genou, et la condition physique du sujet. En outre, l'objectif a été de déterminer l'accélération verticale minimale permettant de stimuler au mieux l'activité musculaire des membres inférieurs. En résumé, les recherches menées au cours de cette thèse fournissent des solutions pour de futures études sur : i) comment supprimer les pics dans le spectre du signal sEMG et, ii) comment normaliser l'activité musculaire pendant un exercice WBV. Enfin, les résultats de cette thèse apportent à la littérature scientifique de nouvelles recommandations pratiques liées à l’utilisation des plateformes vibrantes à des fins d’exercice physiqueThe aim of this thesis was to analyze the effect of whole-body vibration (WBV) exercise on lower limb muscle activity and to give methodological implications and practical applications. Two methodological studies were conducted that served to evaluate the optimal method to process the surface electromyography (sEMG) signals during WBV exercise and to analyze the influence of the normalization method on the sEMG activity. A third study aimed to gain insight whether the isolated spikes in the sEMG spectrum contain motion artifacts and/or reflex activity. The subsequent three investigations aimed to explore how the muscle activity is affected by WBV exercise, with a particular focus on the vibration frequency, platform amplitude, additional loading, platform type, knee flexion angle, and the fitness status of the WBV user. The final goal was to evaluate the minimal required vertical acceleration to stimulate the muscle activity of the lower limbs. In summary, the research conducted for this thesis provides implication for future investigations on how to delete the excessive spikes in the sEMG spectrum and how to normalize the sEMG during WBV. The outcomes of this thesis add to the current literature in providing practical applications for exercising on a WBV platform
8
Klarner, Taryn. "A dissertation on nervous system control and interlimb coordination during rhythmic movement and on locomotor recovery after stroke." Thesis, 2016. http://hdl.handle.net/1828/7672.
Full textAbstract:
For those who have suffered a stroke, damage to the brain can result in a decreased ability to walk. The traditional therapy used for the recovery of walking, body weight supported treadmill training, has significant labour requirements that limit the availability of training to the larger stroke population. Thus, the conception and application of new, effective, and efficient rehabilitation therapies is required.
To approach this, an understating of the intricate neural control behind walking is needed to form the principled foundation upon which locomotor therapies are based. Due to observations that the arms and legs are connected in the nervous system during walking, and that nervous system control is the same across rhythmic tasks, arm and leg (A&L) cycling training could provide an effective means of locomotor rehabilitation.
Thus, the goal of this dissertation is focused upon exploring central nervous system control and interlimb coordination during rhythmic arm and leg movement and testing the extent to which A&L cycling training improves walking after stroke.
The first objective of this dissertation was to provide further evidence of central nervous system control of walking. Through a literature review in Chapter 1 and experimental evidence in Chapter 2 of common subcortical control across rhythmic locomotor tasks, evidence for the existence of central pattern generating networks in humans is given.
The second objective was to explore interlimb coordination during rhythmic movement. Results presented in Chapters 3 and 4 further our understanding of specific interlimb interactions during rhythmic arm and leg tasks.
The third objective was to evaluate the effects of an A&L cycling training intervention in a post-stroke population. To support this objective, it was shown in Chapter 5 that a multiple baseline design is appropriate for use in intervention studies. In Chapter 6, it was determined that A&L cycling training can be used to improve walking ability. And in Chapter 7, it was shown that training induced plasticity in interlimb reflex pathways.
Overall, results in this dissertation provide further knowledge on nervous system control and arm and leg interlimb interactions during rhythmic movements and their effect on locomotor recovery following a stroke.Graduate
2017-10-31
9
Stecina, Katinka. "Preferential suppression of transmission and candidate neurones mediating reflex actions from muscle group II afferents during fictive motor activity." Thesis, 2006. http://hdl.handle.net/1993/270.
Full textAbstract:
This thesis examined two aspects of information processing by the feline spinal cord during centrally-evoked motor activity: 1) the modification of transmission from different sensory afferents and 2) the neuronal elements of reflex pathways from group II muscle afferents during fictive motor behaviours (i.e motoneuron activity under neuromuscular blockade). Fictive locomotion was evoked by electrical stimulation in the midbrain and fictive scratch was triggered by stimulation of the skin covering the ears following curare application to cervical dorsal roots in decerebrate in vivo feline preparations.
Both monosynaptic and longer latency components of muscle and cutaneous afferent-evoked field potentials were reduced in amplitude during fictive locomotion and scratch, but field potentials evoked by muscle group II afferents were suppressed more than those evoked by cutaneous and group I muscle afferents recorded at the same spinal locations. The novel finding, that field potentials evoked at the same spinal locations by muscle and cutaneous afferents are suprressed differently, suggests that there is a preferential and non-uniform control of transmission from muscle and cutaneous fibres during motor activity.
Extracellular recordings from neurons within the lumbar spinal segments showed that suppression of group II afferent input during fictive motor activity results in a powerful reduction of the activation of neurons with input from muscle group II afferents in 93% of the examined neurons after short trains of stimuli were delivered to peripheral nerves. However, more neurons remained recruitable by group II intensity stimulation if train duration was sufficiently long with only 33% showing a reduction in sensory-evoked firing. The majority of the neurons that remained responsive to muscle group II afferent input during fictive locomotion had axonal projections to supralumbar, or supraspinal areas and showed spontaneous, often rhythmic, firing activity.
Overall, the studies presented in this thesis provide insights into the mechanisms by which the mammalian spinal cord processes sensory information and on how sensory input is able to control motor activity in spite of suppressive control provided by the nervous system.October 2006
Books on the topic "Muscle reflex activity"
1
Cai, Bonnie Bao Yan. Sex-related differences in the suppressive effects of peripheral morphine but not GABA on reflex jaw muscle activity evoked by glutamate application to the TMJ region in rats. Ottawa: National Library of Canada, 2001.
Find full text
2
Bobath, Berta. Abnormal postural reflex activity caused by brain lesions. 3rd ed. London: Heinemann Physiotherapy in association with The Chartered Society of Physiotherapy, 1985.
Find full text
3
Chartered Society of Physiotherapy (Great Britain), ed. Abnormal postural reflex activity caused by brain lesions. 3rd ed. London: W. Heinemann Medical Books, 1985.
Find full text
4
Abnormal Postural Reflex Activity Caused by Brain Lesions. 3rd ed. Butterworth-Heinemann, 1991.
Find full text
5
Keshav, Satish, and Alexandra Kent. Unintentional weight loss. Edited by Patrick Davey and David Sprigings. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199568741.003.0080.
Full textAbstract:
Body weight is determined by the combination of metabolic rate, calorie intake, and activity levels. Natural weight loss is usually due to declining muscle mass, with the redistribution of muscle mass in the extremities, leading to greater truncal fat stores. Unintentional weight loss refers to weight loss that is not voluntary, and can reflect serious underlying pathology. It can be caused by inadequate nutritional intake, increased metabolism, malabsorption, or a combination of these factors. Weight loss of 5% of body weight over 6–12 months should be investigated. Cachexia is a complex syndrome in which loss of body mass (fat and protein) cannot be reversed nutritionally, that is, is due to underlying disease processes inducing catabolism, rather than to inadequate nutritional intake.
6
Pfurtscheller, Gert, Clemens Brunner, and Christa Neuper. EEG-Based Brain–Computer Interfaces. Edited by Donald L. Schomer and Fernando H. Lopes da Silva. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228484.003.0047.
Full textAbstract:
A brain–computer interface (BCI) offers an alternative to natural communication and control by recording brain activity, processing it online, and producing control signals that reflect the user’s intent or the current user state. Therefore, a BCI provides a non-muscular communication channel that can be used to convey messages and commands without any muscle activity. This chapter presents information on the use of different electroencephalographic (EEG) features such as steady-state visual evoked potentials, P300 components, event-related desynchronization, or a combination of different EEG features and other physiological signals for EEG-based BCIs. This chapter also reviews motor imagery as a control strategy, discusses various training paradigms, and highlights the importance of feedback. It also discusses important clinical applications such as spelling systems, neuroprostheses, and rehabilitation after stroke. The chapter concludes with a discussion on different perspectives for the future of BCIs.
7
Armstrong, Neil, Alison M. McManus, and Joanne R. Welsman. Aerobic fitness. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199232482.003.0020.
Full textAbstract:
Peak V · O 2 limits the child’s capacity to perform aerobic exercise but it does not describe fully all aspects of aerobic fitness. Exercise of the intensity and duration required to elicit peak V · O 2 is rarely experienced by many young people.17,18 The vast majority ofhabitual physical activity is submaximal and of short duration and, under these circumstances, it is the transient kinetics of V · O 2 which reflect the integrated response of the oxygen delivery system and the metabolic requirements of the exercising muscle.19–21 Furthermore, peak V · O 2 is neither the best measure of a child’s ability to sustain submaximal aerobic exercise nor the most sensitive means to detect improvements in aerobic fitness after a training programme. Despite its origins in anaerobic metabolism, blood lactate accumulation is a valuable indicator of aerobic fitness and it can be used to monitor improvements in muscle oxidative capacity with exercise training in the absence of changes in peak V · O 2 .16,22 However, as V · O 2 kinetics is comprehensively reviewed in Chapter 22 and blood lactate accumulation during exercise is analysed in Chapter 8, we will focus herein on aerobic fitness as described by peak V · O 2 .
Book chapters on the topic "Muscle reflex activity"
1
Dietz, V., I. K. Ibrahim, M. Trippel, and W. Berger. "Spastic Paresis: Reflex Activity and Muscle Tone in Elbow Muscles During Passive and Active Motor Tasks." In Spasticity, 251–65. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-78367-8_24.
Full text
2
Tani, T., K. Kida, H. Yamamoto, and J. Kimura. "Reflexes Evoked in Various Human Muscles During Voluntary Activity." In Spinal Cord Monitoring and Electrodiagnosis, 226–36. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-75744-0_30.
Full text
3
Loeb, G. E., J. A. Hoffer, N. Sugano, W. B. Marks, M. J. O’Donovan, and C. A. Pratt. "Activity Patterns of Identified Alpha Motoneurons to Cat Anterior Thigh Muscles during Normal Walking and Flexor Reflexes." In Motor Control, 159–64. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4615-7508-5_28.
Full text
4
van Gerpen, Jay A., and John N. Caviness. "Long Latency Reflexes and the Silent Period." In Clinical Neurophysiology, 700–706. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190259631.003.0042.
Full textAbstract:
Long latency reflexes (LLRs) are EMG activity occurring during the transition from reflex to voluntary motor activity, which probably arise from a transcortical loop, including afferents within the dorsal column/medial lemniscal system to the sensorimotor cortex and corticospinal tract efferents. Depending upon the site of a lesion and its pathophysiology, LLRs may be absent, delayed, or enhanced. In disorders of cortical hyperexcitability, including cortical myoclonus, an LLR occurring 40–60 ms after stimulation of the median nerve at rest may be present (“C-reflex.”) In response to noxious stimuli to the lower extremities, a polysynaptic network of spinal neurons, flexor reflex afferents, induce a patterned withdrawal response, including hip and knee flexion. These flexor reflexes may aid in the diagnosis of disorders of spinal cord hyperexcitability. Normally, following high stimulation of a peripheral nerve innervating a muscle that is being strongly contracted, no electrical activity occurs for approximately 100 ms (“silent period.”_ In disorders of distal peripheral nerve or muscle hyperexcitability, the silent period may be absent.
5
Cheshire, William P. "Autonomic Physiology." In Clinical Neurophysiology, 617–28. Oxford University Press, 2009. http://dx.doi.org/10.1093/med/9780195385113.003.0035.
Full textAbstract:
The autonomic nervous system consists of three divisions: the sympathetic (thoracolumbar), parasympathetic (craniosacral), and enteric nervous systems. The sympathetic and parasympathetic autonomic outflows involve a two-neuron pathway with a synapse in an autonomic ganglion. Preganglionic sympathetic neurons are organized into various functional units that control specific targets and include skin vasomotor, muscle vasomotor, visceromotor, pilomotor, and sudomotor units. Microneurographic techniques allow recording of postganglionic sympathetic nerve activity in humans. Skin sympathetic activity is a mixture of sudomotor and vasoconstrictor impulses and is regulated mainly by environmental temperature and emotional influences. Muscle sympathetic activity is composed of vasoconstrictor impulses that are strongly modulated by arterial baroreceptors. Heart rate is controlled by vagal parasympathetic and thoracic sympathetic inputs. Vagal influence on the heart rate is strongly modulated by respiration; it is more marked during expiration and is absent during inspiration. This is the basis for the so-called respiratory sinus arrhythmia, which is an important index of vagal innervation of the heart. Power spectral analysis of heart rate fluctuations allows noninvasive assessment of beat-to-beat modulation of neuronal activity affecting the heart. Arterial baroreflex, cardiopulmonary reflexes, venoarteriolar reflex, and ergoreflexes control sympathetic and parasympathetic influences on cardiovascular effectors. The main regulatory mechanism that prevents orthostatic hypotension is reflex arterial vasoconstriction in the splanchnic, renal, and muscular beds triggered by a decrease in transmural pressure at the level of carotid sinus baroreceptors.
6
Dietz, Volker, and Thomas Sinkjaer. "Secondary changes after damage of the central nervous system Significance of spastic muscle tone in rehabilitation." In Oxford Textbook of Neurorehabilitation, edited by Volker Dietz, Nick S. Ward, and Christopher Kennard, 95–110. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198824954.003.0009.
Full textAbstract:
The relationship between clinical spasticity and spastic movement disorder in human adults is covered in this chapter. Exaggerated tendon tap reflexes associated with muscle hypertonia are the clinical signs of central nervous system lesions. Therefore, most antispastic treatments are directed at the reduction of reflex activity. However, a discrepancy exists between spasticity as measured in the clinic and movement disorder. Central motor lesions are associated with a loss of supraspinal drive and defective use of afferent input. These changes lead to paresis and maladaptation of the movement pattern. Secondary changes in mechanical muscle fibre and collagen tissue result in spastic muscle tone, which in part compensates for paresis and allows functional movements on a simpler level of organization. In mobile patients, functional training should be applied to improve both function and spasticity. Antispastic drugs can accentuate paresis and should primarily only be applied in non-ambulatory subjects.
7
Dietz, Volker, and Thomas Sinkjaer. "Secondary changes after damage of the central nervous system: significance of spastic muscle tone in rehabilitation." In Oxford Textbook of Neurorehabilitation, 76–88. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199673711.003.0009.
Full textAbstract:
The relationship between clinical spasticity and spastic movement disorder in human adultsis covered in this chapter. Signs of exaggerated tendon tap reflexes with muscle hypertonia are the consequence of central nervous system lesions. Most antispastic treatments are directed at the reduction of reflex activity. In recent years, a discrepancy between spasticity as measured in the clinic and movement disorder was noticed. Central motor lesions are associated with a loss of supraspinal drive and defective use of afferent input. These changes lead to paresis and maladaptation of the movement pattern. Secondary changes in mechanical muscle fibre and collagen tissue result in spastic muscle tone, which in part compensates for paresis and allows functional movements on a simpler level of organization. In mobile patients functional training should be applied to improve both function and spasticity. Antispastic drugs can accentuate paresis and should primarily only be applied in non-ambulatory subjects.
8
Ahlskog, J. Eric. "Bladder Problems." In Dementia with Lewy Body and Parkinson's Disease Patients. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199977567.003.0023.
Full textAbstract:
Urinary problems occur with normal aging. In women they often relate to the changes in female anatomy due to the delivering of babies. With superimposed age-related changes in soft tissues, laxity may result in incontinence (loss of urinary control), especially with coughing, laughing, or straining. In men the opposite symptom tends to occur: urinary hesitancy (inability to evacuate the bladder). This is due to constriction of the bladder outlet by an enlarging prostate; the prostate normally surrounds the urethra, through which urine passes. DLB and PDD are often associated with additional bladder problems. Recall that the autonomic nervous system regulates bladder function and that this system tends to malfunction in Lewy disorders. Hence, reduced bladder control is frequent among those with DLB, PDD, and Parkinson’s disease. This condition is termed neurogenic bladder, which implies that the autonomic nervous system control of bladder reflexes is not working properly. This may manifest as urgency with incontinence or hesitancy. Neurogenic bladder problems require different strategies than those used for treating the simple age-related problems that develop in mid-life and beyond. Moreover, there are certain caveats to treatment once a neurogenic bladder is recognized. The bladder is simply a reservoir that holds urine. It is located in the lower pelvis and is distant from the kidneys. The kidneys essentially filter the circulating blood and make the urine. The urine flows down from the kidneys into the bladder, as shown in Figure 14.1. Normally, as the bladder slowly fills with urine, a reflex is triggered when it is nearly full. This results in conscious awareness of the need to urinate, plus it primes the reflexive tendency of the bladder to contract in order to expel the urinary contents. The bladder is able to contract because of muscles in the bladder walls. Normally, nerves activate these muscles at the appropriate time, which forcefully squeeze the bladder, expelling the urine. Nerve sensors in the bladder wall are activated by bladder filling and transmit this information to the central nervous system, ramping up bladder wall muscle activity.
9
Atkinson, Martin E. "The autonomic nervous system." In Anatomy for Dental Students. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199234462.003.0025.
Full textAbstract:
A large part of the nervous system is dedicated to the control of the internal viscera and their functions. Much of the activity of these organs is controlled reflexly at the brainstem level, e.g. the cardiovascular and respiratory centres (the vital centres) in the reticular formation of the medulla controlling cardiac and respiratory activity. There are also centres in the cerebrum, notably the hypothalamus in the diencephalon. Somatic and visceral functions are closely integrated at these higher levels; think of the effect that emotional factors or somatic stimulation can have on heart rate, blood pressure, and gastrointestinal activity when we are nervous or are in pain. The nerves involved in these activities are described as visceral sensory or visceral motor nerves because they control visceral function; this distinguishes them from somatic sensory nerves from peripheral receptors and somatic motor nerves controlling voluntary function. Visceral motor neurons innervate smooth muscle and secretory cells of the gastrointestinal and respiratory systems, the smooth and cardiac muscle of the cardiovascular system, the sweat glands and arrector pili muscles of the skin, and the muscles of the ciliary body and iris of the eyeball. In many cases, there is a dual supply from the sympathetic and parasympathetic divisions of the autonomic nervous system. In both divisions of the autonomic nervous system, there is a sequence of two neurons between the CNS and the effector organ which synapse in peripheral autonomic ganglia. The neurons from the CNS to the synapse in the ganglion are the preganglionic neurons and those from the ganglia to the effector organs are the postganglionic neurons. The enteric plexus is a third set of neurons interposed between the post-ganglionic neurons and the effector cells in the gastrointestinal tract. Figure 17.1 compares the general arrangement of the sympathetic and parasympathetic nervous system. The cell bodies of sympathetic visceral preganglionic motor neurons are located in the intermediolateral horns of the thoracic and upper lumbar segments of the spinal cord while those of the parasympathetic visceral preganglionic (secretomotor) neurons are in the nuclei of four of the cranial nerves and the sacral segments of the spinal cord.
10
Hubli, Michèle, and Volker Dietz. "Spinal neuronal dysfunction after deprivation of supraspinal input." In Oxford Textbook of Neurorehabilitation, edited by Volker Dietz, Nick S. Ward, and Christopher Kennard, 83–94. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198824954.003.0008.
Full textAbstract:
A central nervous system lesion can lead to remote structural and functional changes which may limit functional recovery. For example, after a spinal cord injury (SCI) structural and functional alterations of spinal neuronal networks take place: in the first weeks after an SCI, neither locomotor nor spinal reflex (SR) activity can be evoked. Once spinal shock has resolved, an early SR component can be re-evoked and locomotor electromyography (EMG) activity re-appears when appropriate proprioceptive input is provided. In a more chronic stage of SCI alterations in SR components are accompanied by a decline of EMG amplitude in the leg muscles during assisted locomotion. According to rodent experiments it is assumed that the deprivation of supraspinal input and the lack of meaningful proprioceptive input to spinal neuronal networks account for such alterations. A critical combination of sensory cues through physiological training strategies might prevent the development of an undirected neural plasticity.
Conference papers on the topic "Muscle reflex activity"
1
Abraham, P. M., and S. E. Wilson. "Effects of a Lumbar Belt on Neuromotor Transmission of Whole Body Vibration." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42358.
Full textAbstract:
Whole body vibration (WBV) has been identified as a risk factor for low back musculoskeletal disorders and injuries. One potential mechanism by which WBV may lead to low back injury is through stimulation of muscle spindle organs and repetitive activation of the stretch-reflex neuromotor response. Such repetitive activation could lead to muscular fatigue and/or neuromotor adaptation. Understanding mechanical transmission of vibration to the neuromotor system and the resulting neuromotor activation is critical to understanding these mechanisms. In this study, it was theorized that activation of the extensor musculature of the low back is a response to the lengthening and shortening of the extensor musculature. This lengthening and shortening of the extensor musculature may be the result of flexion-extension rotation in the lumbar spine. By measuring lumbar flexion and extension, the amplitude and phase of this lengthening and shortening were assessed. Using electromyographic data from the erector spinae muscle groups at the L2/L3 lumbar level, the cyclic activation of the extensor musculature was also measured. Neuromotor transmission was observed over a frequency range of 3–20 Hz and vibration magnitudes of 1 and 2 m/s^2 RMS. Resonance peaks in lumbar flexion-extension and the integrated electromyographic data were observed at 4 Hz and 10–12 Hz. A lumbar belt was used to reduce transmission of axial seat-pan vibration to lumbar flexion-extension and to observe the changes in cyclic electromyographic activity. The lumbar belt was found to decrease both lumbar flexion-extension and paraspinal muscle activity demonstrating a link between axial seatpan vibration, lumbar flexion-extension and the cyclic activation of the neuromotor system. These results provide information on the neuromotor effects of WBV and may be used to design better low back injury prevention methods.
2
Chen, Kai, and Richard A. Foulds. "The Mechanics of Perturbed Upper Limb Movement Control." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37201.
Full textAbstract:
The dependence of muscle force on muscle length gives rise to a “spring - like” behavior which has been shown to play an important role during movement. This study extended this concept and incorporated the influential factors of the mechanical behavior of the neural, muscular and skeletal system on the control of elbow movement. A significant question in motor control is determining how information about movement is used to modify control signals to achieve desired performance. One theory proposed and supported by Feldman et. is the equilibrium point hypothesis (EPH). In it the central nervous system (CNS) reacts to movement as a shift of the limb’s equilibrium posture. The EPH drastically simplified the requisite computations for multi-joint movements and mechanical interactions with complex dynamic objects in the context. Because the neuromuscular system is spring-like, the instantaneous difference between the arm’s actual position and the equilibrium position specified by the neural activity can generate the requisite torques, avoiding the complex “inverse dynamic” of computing the torques at the joints. Moreover, this instantaneous difference serves as a potential source of movement control related to limb dynamics and associated movement-dependent torques when perturbations are added. In this paper, we have used an EPH model to examine changes to control signals for arm movements in the context of adding perturbations in format of forces or torques. The mechanical properties and reflex actions of muscles crossing the elbow joint were examined during a planned 1 radian voluntary elbow flexion movement. Brief unexpected torque/force pulses of identical magnitude and time duration (4.5 N flexion switching to 50 N extension within 120ms) were introduced at various points of a movement in randomly selected trials. Single perturbation was implemented in different trials during early, mid, stages of the movement by pre-programmed 6DOF robotic arm (MOOG FCS HapticMaster). Changes in movement trajectory induced by a torque/ force perturbation determined over the first 120 ms by a position prediction formulation, and then a modified and optimization K-B-I (stiffness-damping-inertia) model was fit to the responses for predicting both non-perturbed and perturbed movement of elbow. The stiffness and damping coefficients estimate during voluntary movements were compared to values recorded of different subjects during trials. A least square nonlinear optimization model was designed to help determine the optimized impedance a subject could generate, and the identified of adapted of K-B-I in perturbed upper limb movements confirmed our assumption.
3
Shigueva, Tatiana, Vladimir Kitov, Inesa Kozlovskaya, Oleg Orlov, and Elena Tomilovskaya. "EFFECTS OF 21-DAYS DRY IMMERSION ON CHARACTERISTICS OF MOTOR UNIT’S ACTIVITY AND OF REFLEX EXCITABILITY OF CALF EXTENSOR MUSCLES." In XVI International interdisciplinary congress "Neuroscience for Medicine and Psychology". LLC MAKS Press, 2020. http://dx.doi.org/10.29003/m1345.sudak.ns2020-16/530-531.
Full text
4
Lall, Pradeep, Hao Zhang, and Rahul Lall. "Design and Development of Biometric Sensor Wearable Band Using Flexible Electronics." In ASME 2017 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems collocated with the ASME 2017 Conference on Information Storage and Processing Systems. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/ipack2017-74232.
Full textAbstract:
Flexible electronics have a myriad of potential applications in fields such as healthcare, soldier situational awareness, soldier rehabilitation, sports performance, and textile manufacturing among other areas. The primary benefits that flexible electronics provide to both the producers and consumers are their light weight, low power consumption, efficiency, low cost of production, flexibility, and scalability. In comparison to rigid electronics, these systems would be subjected to a greater amount of mechanical and thermal stress in real-time due to their ability to be flexed, rolled, folded, and stretched. Environmental conditions such as bending, mechanical shock, water immersion, sweat, UV radiation, and temperature exposure could degrade the performance of these embedded electronic systems. At this time, there is a lack of suitable test standards and reliability data about flexible electronics manufacturing, assembly, and real-time use. In this paper, a fully flexible medical electronics system was built in full dimension to study the assembly and operation-related failure mechanisms of flexible and wearable electronics. The fabricated flexible electronics system measures pulse and muscle activity, and then transmits this data to a paired mobile device. The pulse rate was measured using an LED and a photo diode, while an electromyography (EMG) sensor was used to measure muscle activity. After collecting the data, the microcontroller sends it to a Bluetooth module, which can in turn transmit this information to a paired mobile device. Through experimentation with the fabricated flexible electronics device, unexpected degradation and quality issues were observed. In flexible PCBs, the space between the IC lead could not be isolated by the solder mask because of its large feature size and as a result, increases the risk of shortage between IC leads when subjected to mechanical stress. In addition, during the assembly process, high reflow temperature was found to subject a huge thermal stress on the connections between the solder pad and copper trace. Proper support of the solder pad should be designed to compensate the thermal stress during the reflow process, and prevent the copper joint on top of the board from being damaged. A set of guidelines for flexible medical electronics and an implementable reliability test standard can, therefore, be established for medical device manufacturers based on these reliability assessments.
5
Chen, Kai, and Richard Foulds. "Optimization of Stiffness and Damping in Modeling of Voluntary Elbow Flexions." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62219.
Full textAbstract:
A subsequent study of obstructed voluntary arm movement extended the relative damping concept, and incorporated the influential factors of the mechanical behavior of the neural, muscular and skeletal system in the control and coordination of arm posture and movement. A significant problem of the study is how this information should be used to modify control signals to achieve desired performance. This study used an Equilibrium Point Hypothesis (EPH) model to examine changes of controlling signals for arm movements in the context of adding perturbation/load in the form of forces/torques. The mechanical properties and reflex actions of muscles of the elbow joint were examined. Brief unexpected torque/force pulses of identical magnitude and time duration were introduced at different stages of the movement in a random order by a pre-programmed 3 degree of freedom (DOF) robotic arm (MOOG FCS HapticMaster). Key to this research is the optimization of B and K for each subject based on their HM only experimental data. The results shown in each of sections confirm that those parameters. Along with an EMG determined VT can be used successfully to model the perturbed trials. The results also show that the subjects may maintain the same control parameters (virtual trajectory, stiffness and damping) regardless of added perturbations that cause substantial changes in EMG activity and kinematics.