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Sample records for involuntary muscle movements

  1. [Involuntary movements: video presentation].

    PubMed

    Ugawa, Yoshikazu

    2012-01-01

    What's involuntary movement? To define the involuntary movement, we should define the voluntary movement. It is, however, difficult to define the voluntariness. The involuntary movement usually indicates some abnormal movement occurring without any movement intention of the subject which excludes any reflex movements, such as tendon reflexes or normal startle response. How to see patients with involuntary movements Classification of involuntary movements entirely depends on clinical features of movements. The method to see the patients, therefore, follows how to describe the movements when explaining those to others. The three main points to care are as follows. Regularity in time or rhythmicity of the movement: regular, mostly regular, irregular or completely irregular. The most rhythmic one is tremor and most irregular one is myoclonus. Conditions inducing involuntary movement: resting, postural, during movement, emotional stress, sensory trick or others. These are important factor to see actual movements in clinical practice. To make an inducing condition in the clinic is sometimes required to see the symptoms. Pattern of involuntary movements: irregular, stereotypical, distribution of moving muscles, right-left difference and others. Several kinds of involuntary movements are presented in my talk.

  2. Atypical involuntary movements following fentanyl anesthesia.

    PubMed

    Lai, Hou-Chuan; Hu, Mei-Hua; Liaw, Wen-Jinn; Lu, Chueng-He; Huang, Go-Shine

    2013-02-01

    Postanesthetic involuntary movements are triggered by a variety of drugs, including propofol, sevoflurane, anti-emetics, and anti-psychotics. A case of acute involuntary movements in a healthy man after fentanyl exposure is presented. The movements consisted of large-amplitude motions of the upper limbs of the elbow joint for flexion and extension, and shaking of the head from side to side. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Sensorimotor organization of a sustained involuntary movement

    PubMed Central

    De Havas, Jack; Ghosh, Arko; Gomi, Hiroaki; Haggard, Patrick

    2015-01-01

    Involuntary movements share much of the motor control circuitry used for voluntary movement, yet the two can be easily distinguished. The Kohnstamm phenomenon (where a sustained, hard push produces subsequent involuntary arm raising) is a useful experimental model for exploring differences between voluntary and involuntary movement. Both central and peripheral accounts have been proposed, but little is known regarding how the putative Kohnstamm generator responds to afferent input. We addressed this by obstructing the involuntary upward movement of the arm. Obstruction prevented the rising EMG pattern that characterizes the Kohnstamm. Importantly, once the obstruction was removed, the EMG signal resumed its former increase, suggesting a generator that persists despite peripheral input. When only one arm was obstructed during bilateral involuntary movements, only the EMG signal from the obstructed arm showed the effect. Upon release of the obstacle, the obstructed arm reached the same position and EMG level as the unobstructed arm. Comparison to matched voluntary movements revealed a preserved stretch response when a Kohnstamm movement first contacts an obstacle, and also an overestimation of the perceived contact force. Our findings support a hybrid central and peripheral account of the Kohnstamm phenomenon. The strange subjective experience of this involuntary movement is consistent with the view that movement awareness depends strongly on efference copies, but that the Kohnstamm generator does not produces efference copies. PMID:26283934

  4. Movement - uncontrolled or slow

    MedlinePlus

    Dystonia; Involuntary slow and twisting movements; Choreoathetosis; Leg and arm movements - uncontrollable; Arm and leg movements - uncontrollable; Slow involuntary movements of large muscle groups; Athetoid movements

  5. Involuntary movements misdiagnosed as seizure during vitamin B12 treatment.

    PubMed

    Carman, Kursat Bora; Belgemen, Tugba; Yis, Uluc

    2013-11-01

    Seizures and epilepsy are a common problem in childhood. Nonepileptic paroxysmal events are conditions that can mimic seizure and frequent in early childhood. Nonepileptic paroxysmal events can be due to physiological or exaggerated physiological responses, parasomnias, movement disorders, behavioral or psychiatric disturbances, or to hemodynamic, respiratory, or gastrointestinal dysfunction. Vitamin B12 deficiency is a treatable cause of failure to thrive and developmental regression, involuntary movements, and anemia. Involuntary movements rarely may appear a few days after the initiation of vitamin B12 treatments and might be misdiagnosed as seizure. Here, we report 2 patients who presented with involuntary movements with his video image.

  6. EMG patterns in abnormal involuntary movements induced by neuroleptics.

    PubMed

    Bathien, N; Koutlidis, R M; Rondot, P

    1984-09-01

    Electromyographic (EMG) activity of abnormal involuntary movements and their modifications after Piribedil, a dopaminergic agonist, were analysed in patients presenting with tremor or tardive dyskinesia induced by treatment with neuroleptics. Quantitative analysis of EMG bursts and of their phase relationships with bursts of antagonist muscles revealed differences between tremor and tardive dyskinesia; three separate EMG types of the latter were found. In tremor, EMG activity was coordinated between agonists and antagonists. Length and frequency of bursts are characteristic. In tardive dyskinesia, phase histograms of antagonist muscle bursts showed an absence of reciprocal organisation of EMG activity. This activity was made up of either rhythmical bursts (type I and II according to the frequency) or irregular discharges (type III). Piribedil decreased tremor but facilitated EMG activity in tardive dyskinesia. These results give an objective measurement or classification of tremor and tardive dyskinesia induced by neuroleptics.

  7. EMG patterns in abnormal involuntary movements induced by neuroleptics.

    PubMed Central

    Bathien, N; Koutlidis, R M; Rondot, P

    1984-01-01

    Electromyographic (EMG) activity of abnormal involuntary movements and their modifications after Piribedil, a dopaminergic agonist, were analysed in patients presenting with tremor or tardive dyskinesia induced by treatment with neuroleptics. Quantitative analysis of EMG bursts and of their phase relationships with bursts of antagonist muscles revealed differences between tremor and tardive dyskinesia; three separate EMG types of the latter were found. In tremor, EMG activity was coordinated between agonists and antagonists. Length and frequency of bursts are characteristic. In tardive dyskinesia, phase histograms of antagonist muscle bursts showed an absence of reciprocal organisation of EMG activity. This activity was made up of either rhythmical bursts (type I and II according to the frequency) or irregular discharges (type III). Piribedil decreased tremor but facilitated EMG activity in tardive dyskinesia. These results give an objective measurement or classification of tremor and tardive dyskinesia induced by neuroleptics. PMID:6148381

  8. [Cryptococcal meningoencephalitis presenting with treatable cognitive impairment and involuntary movement].

    PubMed

    Ikumi, Kazuhiro; Yokoi, Katsunori; Ando, Tetsuo

    2016-01-01

    The patient is a 72-year-old Japanese woman. Seven years prior to admission, multiple nodules in her left lung were found. Bronchoscopic biopsy of the nodules did not provide a confirmative diagnosis, and probable diagnosis of cryptococcosis was made. Follow-up CT scan of the chest revealed reduction in size of the lung nodules. She was admitted to our hospital due to progressive cognitive impairment and difficulty in walking that lasted for 5 months. On admission, athetotic involuntary movement was observed in her lower extremities, predominantly in the right side. Blood and cerebrospinal fluid culture of the patient were positive for Cryptococcus neoformans. Antifungal drugs resolved the cognitive impairment, the difficulty in walking, and the involuntary movement. We assessed the cognitive impairment and observed the clinical improvement of the patient, with the use of neuropsychological examinations. To our knowledge, there has been only a few reported case of cryptococcal meningoencephalitis presenting with treatable cognitive impairment and involuntary movement.

  9. Subjective experience, involuntary movement, and posterior alien hand syndrome

    PubMed Central

    Bundick, T; Spinella, M

    2000-01-01

    The alien hand syndrome, as originally defined, was used to describe cases involving anterior corpus callosal lesions producing involuntary movement and a concomitant inability to distinguish the affected hand from an examiner's hand when these were placed in the patient's unaffected hand. In recent years, acceptable usage of the term has broadened considerably, and has been defined as involuntary movement occurring in the context of feelings of estrangement from or personification of the affected limb or its movements. Three varieties of alien hand syndrome have been reported, involving lesions of the corpus callosum alone, the corpus callosum plus dominant medial frontal cortex, and posterior cortical/subcortical areas. A patient with posterior alien hand syndrome of vascular aetiology is reported and the findings are discussed in the light of a conceptualisation of posterior alien hand syndrome as a disorder which may be less associated with specific focal neuropathology than are its callosal and callosal-frontal counterparts.

 PMID:10601408

  10. Airflow synchronous with oscillatory acceleration reflects involuntary respiratory muscle activity.

    PubMed

    Brown, Richard E; Lee, Hsueh-Tze; Loring, Stephen H

    2004-06-25

    To explore mechanisms causing involuntary airflow synchronous with oscillatory axial whole body acceleration (oscillatory axial acceleration, OAA) such as that during locomotion, we monitored airflow, acceleration, and electromyograms (EMGs) of the rib cage and abdominal muscles in standing subjects undergoing OAA at 3, 6, and 9 Hz at accelerations of 0.1-0.95 g. Subjects relaxed or performed static respiratory maneuvers at constant lung volume with glottis open. Oscillatory airflows (0.01-3.01 s(-1)) synchronous with OAA were not consistent with expectations for a passive respiratory system, and were larger during active respiratory efforts than during relaxation. Peak inspiratory airflow usually preceded peak upward acceleration by 90-180 degrees. In 80% of runs with respiratory muscles voluntarily activated or relaxed, EMGs showed activity synchronous with OAA. Changes in periodic muscle activity coincided with changes in oscillatory airflow. We conclude that periodic muscle activity, probably a reflex response to body wall deformation during OAA, strongly influences the involuntary airflow synchronous with OAA.

  11. Contractures and involuntary muscle overactivity in severe brain injury.

    PubMed

    Pohl, Marcus; Mehrholz, Jan; Rockstroh, Günter; Rückriem, Stefan; Koch, Rainer

    2007-04-01

    The aim of the present study was to evaluate the association of contractures with an increase or reduction of non-spastic muscle overactivity due to severe cerebral damage. Forty-five patients with tetraparesis after severe cerebral damage were investigated. Three groups were defined based on the presence of spasticity (revealed as resistance to passive stretch (= hypertonia)), and the presence of contracture of the relevant knee joint: Group(s) (17 patients with hypertonia without contracture), Group(s+c) (20 patients with hypertonia and contracture), and Group(c) (eight patients without hypertonia and with contracture). In all groups spontaneous involuntary muscle activity was assessed continuously over a 12-hour period through isometric measurement of knee joint flexion torque. A mathematical algorithm differentiated an hourly muscle activity spectrum (PI(h)). The frequency of peaks (peaks(h)) from the activity spectrum was determined. We revealed that Group(s) had higher PI(h) and more frequent peaks(h) compared with Group(s+c) and Group(c) (p<0.05). Group(c) had comparable PI(h) and peaks(h) compared with Group(s+c) (p>0.05). The presence of contractures was associated with lower involuntary muscle overactivity in terms of lower PI(h) and less frequent peaks(h), indicating that contractures may be associated with reduced non-spastic positive features of the upper motor neurone syndrome in patients with severe brain damage.

  12. Involuntary movements due to vitamin B12 deficiency.

    PubMed

    de Souza, Aaron; Moloi, M W

    2014-12-01

    Deficiency of vitamin B12 produces protean effects on the nervous system, most commonly neuropathy, myelopathy, cognitive and behavioural symptoms, and optic atrophy. Involuntary movements comprise a relatively rare manifestation of this readily treatable disorder. Both adults and infants deficient in vitamin B12 may present with chorea, tremor, myoclonus, Parkinsonism, dystonia, or a combination of these, which may precede diagnosis or become apparent only a few days after parenteral replacement therapy has begun. The pathogenesis of these movement disorders shows interesting parallels to certain neurodegenerative conditions. The clinical syndrome responds well to vitamin B12 supplementation in most cases, and an early diagnosis is essential to reverse the haematological and neurological dysfunction characteristic of this disorder. In this article, we elucidate the association of vitamin B12 deficiency with movement disorders in adults and in infants, discuss the pathogenesis of this association, review previously reported cases, and present a young adult male with severe generalized chorea that showed a salutary response to vitamin B12 supplementation.

  13. Induction of involuntary movements by peripheral trauma: an analogy with causalgia.

    PubMed

    Schott, G D

    1986-09-27

    Ten patients are described in whom various involuntary movement disorders developed after trauma that was predominantly or entirely peripheral. The interval between injury and onset of movement disorder ranged from 48 hours to 3 years; the injured and painful part was the area initially affected by involuntary movements, although more widespread involvement subsequently occurred. These clinical features resemble the phenomena experienced by some patients with causalgia and suggest the possibility of common mechanisms.

  14. Classification of involuntary movements in dogs: Tremors and twitches.

    PubMed

    Lowrie, Mark; Garosi, Laurent

    2016-08-01

    This review focuses on important new findings in the field of involuntary movements (IM) in dogs and illustrates the importance of developing a clear classification tool for diagnosing tremor and twitches. Developments over the last decade have changed our understanding of IM and highlight several caveats in the current tremor classification. Given the ambiguous association between tremor phenomenology and tremor aetiology, a more cautious definition of tremors based on clinical assessment is required. An algorithm for the characterisation of tremors is presented herein. The classification of tremors is based on the distinction between tremors that occur at rest and tremors that are action-related; tremors associated with action are divided into postural or kinetic. Controversial issues are outlined and thus reflect the open questions that are yet to be answered from an evidence base of peer-reviewed published literature. Peripheral nerve hyper-excitability (PNH; cramps and twitches) may manifest as fasciculations, myokymia, neuromyotonia, cramps, tetany and tetanus. It is anticipated that as we learn more about the aetiology and pathogenesis of IMs, future revisions to the classification will be needed. It is therefore the intent of this work to stimulate discussions and thus contribute to the development of IM research.

  15. Involuntary movements after correction of vitamin B12 deficiency: a video-case report.

    PubMed

    Zanus, Caterina; Alberini, Elena; Costa, Paola; Colonna, Franco; Zennaro, Floriana; Carrozzi, Marco

    2012-06-01

    Involuntary movements can appear before and after initiation of vitamin B12 treatment. The pathogenesis of involuntary movements in vitamin B12 deficiency and their relationship with cobalamin injection remain unclear due to a lack of video-EEG documentation making the electroclinical correlation difficult to ascertain. Here, we report video-EEG and neuroimaging findings of an 11-month-old girl with vitamin B12 deficiency, who acutely developed involuntary movements a few days after initiation of vitamin B12 treatment with normal vitamin plasmatic levels. Abnormal movements were a combination of tremor and myoclonus involving the face, mouth, and left arm, which disappeared after discontinuation of therapy. [Published with video sequences].

  16. A case of hyperosmolar hyperglycaemic state with involuntary movements – diagnostic dilemma and clinical considerations

    PubMed Central

    Abd Hamid, Hanisah; Othman, Hanita; Das, Srijit

    2010-01-01

    Hyperosmolar hyperglycaemic state (HHS) is a medical emergency which needs immediate medical intervention. A 37-year-old Chinese woman with a history of hypertension attended the Emergency Department. She had a two-day history of involuntary movement, i.e. chorea of the upper limbs, preceded by a one-week history of upper respiratory tract infection. She also had polyuria and polydipsia, although she was never diagnosed as diabetic. The main aim of reporting the present case was to highlight the importance of biochemical investigations involved in the diagnosis of involuntary movements. PMID:22427779

  17. A new neurological entity manifesting as involuntary movements and dysarthria with possible abnormal copper metabolism

    PubMed Central

    Tagawa, A; Ono, S; Shibata, M; Imai, T; Suzuki, M; Shimizu, N

    2001-01-01

    A few patients with an affected CNS involving abnormalities in copper metabolism have been described that do not fit any known nosological entities such as Wilson's disease or Menkes' disease.
Three sporadic patients (two men and one woman) were examined with involuntary movements and dysarthria associated with abnormal concentrations of serum copper, serum ceruloplasmin, and urinary copper excretion. The onset of neurological symptoms occurred at the age of 15 to 17 years. The common clinical symptoms were involuntary movements and dysarthria. The involuntary movements included dystonia in the neck, myoclonus in the shoulder, athetosis in the neck, and rapid orobuccal movements. The dysarthria consisted of unclear, slow, and stuttering speech. Two of the three patients did not have dementia. A cousin of the female patient had been diagnosed as having Wilson's disease and had died of liver cirrhosis. Laboratory findings showed a mild reduction in serum copper and ceruloplasmin concentrations, whereas urinary copper excretion was significantly reduced in all three patients. Two of the three patients showed a high signal intensity in the basal ganglia on T2 weighted brain MRI.
In conclusion, the unique findings of involuntary movements, dysarthria, and abnormal serum copper and urinary copper concentrations suggest that the three patients may constitute a new clinical entity that is distinct from either Wilson's or Menkes disease.

 PMID:11723201

  18. Facial movements strategically camouflage involuntary social signals of face morphology.

    PubMed

    Gill, Daniel; Garrod, Oliver G B; Jack, Rachael E; Schyns, Philippe G

    2014-05-01

    Animals use social camouflage as a tool of deceit to increase the likelihood of survival and reproduction. We tested whether humans can also strategically deploy transient facial movements to camouflage the default social traits conveyed by the phenotypic morphology of their faces. We used the responses of 12 observers to create models of the dynamic facial signals of dominance, trustworthiness, and attractiveness. We applied these dynamic models to facial morphologies differing on perceived dominance, trustworthiness, and attractiveness to create a set of dynamic faces; new observers rated each dynamic face according to the three social traits. We found that specific facial movements camouflage the social appearance of a face by modulating the features of phenotypic morphology. A comparison of these facial expressions with those similarly derived for facial emotions showed that social-trait expressions, rather than being simple one-to-one overgeneralizations of emotional expressions, are a distinct set of signals composed of movements from different emotions. Our generative face models represent novel psychophysical laws for social sciences; these laws predict the perception of social traits on the basis of dynamic face identities.

  19. Phenotypic spectrum of GNAO1 variants: epileptic encephalopathy to involuntary movements with severe developmental delay

    PubMed Central

    Saitsu, Hirotomo; Fukai, Ryoko; Ben-Zeev, Bruria; Sakai, Yasunari; Mimaki, Masakazu; Okamoto, Nobuhiko; Suzuki, Yasuhiro; Monden, Yukifumi; Saito, Hiroshi; Tziperman, Barak; Torio, Michiko; Akamine, Satoshi; Takahashi, Nagahisa; Osaka, Hitoshi; Yamagata, Takanori; Nakamura, Kazuyuki; Tsurusaki, Yoshinori; Nakashima, Mitsuko; Miyake, Noriko; Shiina, Masaaki; Ogata, Kazuhiro; Matsumoto, Naomichi

    2016-01-01

    De novo GNAO1 variants have been found in four patients including three patients with Ohtahara syndrome and one patient with childhood epilepsy. In addition, two patients showed involuntary movements, suggesting that GNAO1 variants can cause various neurological phenotypes. Here we report an additional four patients with de novo missense GNAO1 variants, one of which was identical to that of the previously reported. All the three novel variants were predicted to impair Gαo function by structural evaluation. Two patients showed early-onset epileptic encephalopathy, presenting with migrating or multifocal partial seizures in their clinical course, but the remaining two patients showed no or a few seizures. All the four patients showed severe intellectual disability, motor developmental delay, and involuntary movements. Progressive cerebral atrophy and thin corpus callosum were common features in brain images. Our study demonstrated that GNAO1 variants can cause involuntary movements and severe developmental delay with/without seizures, including various types of early-onset epileptic encephalopathy. PMID:25966631

  20. Striatal overexpression of ΔFosB reproduces chronic levodopa-induced involuntary movements

    PubMed Central

    Cao, Xuebing; Yasuda, Toru; Uthayathas, Subramaniam; Watts, Ray L.; Mouradian, M. Maral; Mochizuki, Hideki; Papa, Stella M.

    2010-01-01

    Long-term dopamine replacement therapy in Parkinson’s disease leads to the development of disabling involuntary movements named dyskinesias that are related to adaptive changes in striatal signaling pathways. The chronic transcription factor ΔFosB, which is overexpressed in striatal neurons after chronic dopaminergic drug exposure, is suspected to mediate these adaptive changes. Here, we sought to demonstrate the ability of ΔFosB to lead directly to the abnormal motor responses associated with chronic dopaminergic therapy. Using rAAV viral vectors, high levels of ΔFosB expression were induced in the striatum of dopamine-denervated rats naïve of chronic drug administration. Transgenic ΔFosB overexpression reproduced the entire spectrum of altered motor behaviors in response to acute levodopa tests, including different types of abnormal involuntary movements and hypersensitivity of rotational responses that are typically associated with chronic levodopa treatment. JunD, the usual protein partner of ΔFosB binding to AP-1 sites of genes, remained unchanged in rats with high ΔFosB expression induced by viral vectors. These findings demonstrate that the increase of striatal ΔFosB in the evolution of chronically treated Parkinson’s disease may be a trigger for the development of abnormal responsiveness to dopamine and the emergence of involuntary movements. PMID:20505100

  1. Size of the superior palpebral involuntary muscle (Müller muscle).

    PubMed

    Hwang, Kun; Huan, Fan; Kim, Dae Joong; Hwang, Se Ho

    2010-09-01

    The aim of this study was to elucidate the width and length of the superior palpebral muscle by using anti-α-smooth muscle actin antibody. Ten orbits of 5 adult Korean cadavers were used. Eyelids were cut in vertical planes through midpupilliary, medial limbus, and lateral limbus and in horizontal planes at the anterior border of the superior transverse ligament and 2 mm proximal to the upper tarsal border. Superior palpebral muscle was localized using mouse monoclonal anti-α-smooth muscle actin and counterstained with light green for collagen. In enlarged pictures of sections, widths, lengths, and thicknesses of the superior palpebral involuntary muscle were measured with a curved scale and were analyzed. The levator palpebrae superioris muscle was divided into superficial and deep parts below the superior transverse ligament. The levator aponeurosis originated from the superficial part and the superior palpebral muscle originated from the deep part of the levator palpebrae superioris muscle. The aponeurosis was inserted into the upper border of tarsus. The superior palpebral muscle fibers arose 2.71 ± 0.64 mm posterior to the anterior border of the superior transverse ligament. The superior palpebral muscle was trapezoidal. The lengths of its sides were 15.58 ± 1.82 and 22.30 ± 5.25 mm, and its height was 13.70 ± 2.74 mm. The levator aponeurosis covered the superior palpebral muscle anteriorly. The width of the levator aponeurosis was approximately 4 mm wider than the superior palpebral muscle. The thicknesses of the superior palpebral muscle were 0.14 ± 0.13 mm at the anterior border of the superior transverse ligament, 0.45 ± 0.11 mm at the superior fornix level, and 0.10 ± 0.03 mm at the upper border of the tarsal plate. One vascular layer was between the levator aponeurosis and the superior palpebral muscle (upper vascular layer), and the other was between the superior palpebral muscle and the conjunctiva (lower vascular layer). At the superior

  2. Involuntary human hand movements due to FM radio waves in a moving van.

    PubMed

    Huttunen, P; Savinainen, A; Hänninen, Osmo; Myllylä, R

    2011-06-01

    Finland TRACT Involuntary movements of hands in a moving van on a public road were studied to clarify the possible role of frequency modulated radio waves on driving. The signals were measured in a direct 2 km test segment of an international road during repeated drives to both directions. Test subjects (n=4) had an ability to sense radio frequency field intensity variations of the environment. They were sitting in a minivan with arm movement detectors in their hands. A potentiometer was used to register the hand movements to a computer which simultaneously collected data on the amplitude of the RF signal of the local FM tower 30 km distance at a frequency of about 100 MHz. Involuntary hand movements of the test subjects correlated with electromagnetic field, i.e. FM radio wave intensity measured. They reacted also on the place of a geomagnetic anomaly crossing the road, which was found on the basis of these recordings and confirmed by the public geological maps of the area.In conclusion, RF irradiation seems to affect the human hand reflexes of sensitive persons in a moving van along a normal public road which may have significance in traffic safety.

  3. [Intercultural adaptation of the AIMS in German language: A scale for abnormal involuntary movements].

    PubMed

    Buhmann, C; Rizos, A; Emmans, D; Jost, W H

    2016-04-01

    Dyskinesias are abnormal involuntary movements and occur across many movement disorders. In Parkinson's disease dyskinesias can be troublesome and are a determinant of the quality of life throughout the course of the disease. Assessment and rating of dyskinesias is thus important for clinical assessment of patients, as well as for academic studies and clinical trials. The abnormal involuntary movement scale (AIMS) is an English language standardised, reliable and validated scale to evaluate dyskinesias. In this article we present a linguistically validated German version of AIMS. The intercultural adaptation of the German translation was performed following an internationally accepted procedure. Firstly, two neurologists independently translated the original into German. Taking both versions into account, a consensus version was agreed on by both translators and was tested on 10 patients. This preliminary German version was then independently translated back into the original language by two different neurologists, and again, a consensus version was agreed on. All translators then compared this English version to the original. Subsequently, the German version was linguistically modified until it resulted in a final German version, which was agreed on by all translators, deemed linguistically acceptable, and the translation back into English was considered to be as unambiguous as possible. This final German version of AIMS was applied to 50 patients in two different hospitals for diagnostic purposes and tested for feasibility and comprehension. In this paper, we present an intercultural adaptation of a linguistically validated German version of AIMS.

  4. Study of the Effect of Involuntary User Movement on the Potential Light Hazards from Some Ophthalmic Instruments

    NASA Astrophysics Data System (ADS)

    Landry, Robert; Wolffe, Michael; Burrows, Clive; Rassow, Bernhard; Byrnes, Gordon

    2004-03-01

    A study was undertaken to determine whether involuntary user movement provides a basis for relaxing the measurement conditions for evaluating the potential optical radiation hazards to the eye from slit lamps and indirect ophthalmoscopes. This was accomplished by assessment of the extent to which light from these devices can be maintained in focus on a 1-mm-diameter fiber-optic cable for 45 s. The results suggest that, although involuntary user movements can be significant, they do not provide a basis for relaxing the measurement conditions for evaluating the potential optical radiation hazards to the cornea and lens from slit lamps and indirect ophthalmoscopes.

  5. Assessment of involuntary choreatic movements in Huntington's disease--toward objective and quantitative measures.

    PubMed

    Reilmann, Ralf; Bohlen, Stefan; Kirsten, Florian; Ringelstein, E Bernd; Lange, Herwig W

    2011-10-01

    Objective measures of motor impairment may improve the sensitivity and reliability of motor end points in clinical trials. In Huntington's disease, involuntary choreatic movements are one of the hallmarks of motor dysfunction. Chorea is commonly assessed by subitems of the Unified-Huntington's Disease Rating Scale. However, clinical rating scales are limited by inter- and intrarater variability, subjective error, and categorical design. We hypothesized that assessment of position and orientation changes interfering with a static upper extremity holding task may provide objective and quantitative measures of involuntary movements in patients with Huntington's disease. Subjects with symptomatic Huntington's disease (n = 19), premanifest gene carriers (n = 15; Unified-Huntington's Disease Rating Scale total motor score ≤ 3), and matched controls (n = 19) were asked to grasp and lift a device (250 and 500 g) equipped with an electromagnetic sensor. While subjects were instructed to hold the device as stable as possible, changes in position (x, y, z) and orientation (roll, pitch, yaw) were recorded. These were used to calculate a position index and an orientation index, both depicting the amount of choreatic movement interfering with task performance. Both indices were increased in patients with symptomatic Huntington's disease compared with controls and premanifest gene carriers for both weights, whereas only the position index with 500 g was increased in premanifest gene carriers compared with controls. Correlations were observed with the Disease Burden Score based on CAG-repeat length and age and with the Unified-Huntington's Disease Rating Scale. We conclude that quantitative assessment of chorea is feasible in Huntington's disease. The method is safe, noninvasive, and easily applicable and can be used repeatedly in outpatient settings. A use in clinical trials should be further explored in larger cohorts and follow-up studies.

  6. Effect of simvastatin on L-DOPA-induced abnormal involuntary movements of hemiparkinsonian rats.

    PubMed

    Wang, Tan; Cao, Xuebin; Zhang, Tian; Shi, Qingqing; Chen, Zhibin; Tang, Beisha

    2015-08-01

    Chronic L-3,4-dihydroxyphenylalanine (L-DOPA) treatment of Parkinson's disease (PD) often results in debilitating involuntary movements known as L-DOPA-induced dyskinesia (LID), which is the main obstacle in PD. The abnormal involuntary movements (AIMs) are consistently involved with the activation of the Ras-extracellular signal-regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) signaling pathway. Previous research has also shown that blockade of ERK phosphorylation could reduce the induction of LID. Consequently, inhibitors of MAPK signaling cascade that block the aberrant supersensitive response of direct pathway striatal neurons could provide a novel therapeutic adjunct to L-DOPA in the treatment of PD. Statins, a specific inhibitor of the rate-limiting enzyme in cholesterol biosynthesis, can also inhibit Ras isoprenylation and activity, and the subsequent phosphorylation of ERK1/2 (pERK1/2). Simvastatin, a representative of statins, could reduce L-DOPA-induced AIM incidence and severity in the 6-hydroxydopamine (6-OHDA) rat model of PD by preventing the L-DOPA/benserazide-induced increase in pERK1/2 levels in our study. The simvastatin-L-DOPA/benserazide-treated 6-OHDA animals displayed less severe rotational behavior and a dramatic reduction in AIM severity than the L-DOPA/benserazide-treated ones. This lower AIM severity was related to a decrease in L-DOPA-induced increase in the following: (1) striatal pERK1/2 and (2) FosB levels. These results suggest that simvastatin could represent a treatment option for managing LID in PD.

  7. A Genetic Mouse Model of Parkinson's Disease Shows Involuntary Movements and Increased Postsynaptic Sensitivity to Apomorphine.

    PubMed

    Brehm, N; Bez, F; Carlsson, T; Kern, B; Gispert, S; Auburger, G; Cenci, M A

    2015-12-01

    Alpha-synuclein (SNCA) protein aggregation plays a causal role in Parkinson's disease (PD). The SNCA protein modulates neurotransmission via the SNAP receptor (SNARE) complex assembly and presynaptic vesicle trafficking. The striatal presynaptic dopamine deficit is alleviated by treatment with levodopa (L-DOPA), but postsynaptic plastic changes induced by this treatment lead to a development of involuntary movements (dyskinesia). While this process is currently modeled in rodents harboring neurotoxin-induced lesions of the nigrostriatal pathway, we have here explored the postsynaptic supersensitivity of dopamine receptor-mediated signaling in a genetic mouse model of early PD. To this end, we used mice with prion promoter-driven overexpression of A53T-SNCA in the nigrostriatal and corticostriatal projections. At a symptomatic age (18 months), mice were challenged with apomorphine (5 mg/kg s.c.) and examined using both behavioral and molecular assays. After the administration of apomorphine, A53T-transgenic mice showed more severe stereotypic and dystonic movements in comparison with wild-type controls. Molecular markers of extracellular signal-regulated kinase 1 and 2 (ERK1/2) phosphorylation and dephosphorylation, and Fos messenger RNA (mRNA), were examined in striatal tissue at 30 and 100 min after apomorphine injection. At 30 min, wild-type and transgenic mice showed a similar induction of phosphorylated ERK1/2, Dusp1, and Dusp6 mRNA (two MAPK phosphatases). At the same time point, Fos mRNA was induced more strongly in mutant mice than in wild-type controls. At 100 min after apomorphine treatment, the induction of both Fos, Dusp1, and Dusp6 mRNA was significantly larger in mutant mice than wild-type controls. At this time point, apomorphine caused a reduction in phospho-ERK1/2 levels specifically in the transgenic mice. Our results document for the first time a disturbance of ERK1/2 signaling regulation associated with apomorphine-induced involuntary movements

  8. Complete resolution of myoclonus-like involuntary movements under subarachnoid block after midazolam administration in a patient undergoing cesarean section: a case report.

    PubMed

    Nakamoto, Takahiro; Hirota, Kiichi; Iwai, Teppei; Shingu, Koh

    2015-04-01

    Involuntary movement during and after neuraxial anesthesia, such as spinal and epidural anesthesia, is rarely observed. In this report, we describe a case of myoclonus-like involuntary movement of the upper extremities in a patient undergoing a planned repeat cesarean section under spinal anesthesia with bupivacaine that completely subsided after administration of 2 mg of midazolam. The myoclonus-like movement did not recur or cause any apparent neurological side effects.

  9. Palmitoyl Serotonin Inhibits L-dopa-induced Abnormal Involuntary Movements in the Mouse Parkinson Model

    PubMed Central

    Park, Hye-Yeon; Ryu, Young-Kyoung; Go, Jun; Son, Eunjung

    2016-01-01

    L-3,4-dihydroxyphenylalanine (L-DOPA) is the most common treatment for patients with Parkinson's disease (PD). However, long term use of L-DOPA for PD therapy lead to abnormal involuntary movements (AIMs) known as dyskinesia. Fatty acid amide hydrolase (FAAH) is enriched protein in basal ganglia, and inhibition of the protein reduces dyskinetic behavior of mice. Palmitoyl serotonin (PA-5HT) is a hybrid molecule patterned after arachidonoyl serotonin, antagonist of FAAH. However, the effect of PA-5HT on L-DOPA-induced dyskinesia (LID) in PD have not yet been elucidated. To investigate whether PA-5HT relieve LID in PD and decrease hyperactivation of dopamine D1 receptors, we used the 6-hydroxydopomine (6-OHDA)-lesioned mouse model of PD and treated the L-DOPA (20 mg/kg) for 10 days with PA-5HT (0.3 mg/kg/day). The number of wall contacts with the forelimb in the cylinder test was significantly decreased by 6-OHDA lesion in mice and the pharmacotherapeutic effect of L-DOPA was also revealed in PA-5HT-treated mice. Moreover, in AIMs test, PA-5HT-treated mice showed significant reduction of locomotive, axial, limb, and orofacial AIMs score compared to the vehicle-treated mice. LID-induced hyper-phosphorylation of ERK1/2 and overexpression of FosB/ΔFosB was markedly decreased in 6-OHDA-lesioned striatum of PA-5HT-treated mice, indicating that PA-5HT decreased the dopamine D1 receptor-hyperactivation induced by chronic treatment of L-DOPA in dopamine-denervated striatum. These results suggest that PA-5HT effectively attenuates the development of LID and enhance of ERK1/2 phosphorylation and FosB/ΔFosB expression in the hemi-parkinsonian mouse model. PA-5HT may have beneficial effect on the LID in PD. PMID:27574484

  10. The Dynamics of Voluntary Force Production in Afferented Muscle Influence Involuntary Tremor

    PubMed Central

    Laine, Christopher M.; Nagamori, Akira; Valero-Cuevas, Francisco J.

    2016-01-01

    Voluntary control of force is always marked by some degree of error and unsteadiness. Both neural and mechanical factors contribute to these fluctuations, but how they interact to produce them is poorly understood. In this study, we identify and characterize a previously undescribed neuromechanical interaction where the dynamics of voluntary force production suffice to generate involuntary tremor. Specifically, participants were asked to produce isometric force with the index finger and use visual feedback to track a sinusoidal target spanning 5–9% of each individual's maximal voluntary force level. Force fluctuations and EMG activity over the flexor digitorum superficialis (FDS) muscle were recorded and their frequency content was analyzed as a function of target phase. Force variability in either the 1–5 or 6–15 Hz frequency ranges tended to be largest at the peaks and valleys of the target sinusoid. In those same periods, FDS EMG activity was synchronized with force fluctuations. We then constructed a physiologically-realistic computer simulation in which a muscle-tendon complex was set inside of a feedback-driven control loop. Surprisingly, the model sufficed to produce phase-dependent modulation of tremor similar to that observed in humans. Further, the gain of afferent feedback from muscle spindles was critical for appropriately amplifying and shaping this tremor. We suggest that the experimentally-induced tremor may represent the response of a viscoelastic muscle-tendon system to dynamic drive, and therefore does not fall into known categories of tremor generation, such as tremorogenic descending drive, stretch-reflex loop oscillations, motor unit behavior, or mechanical resonance. Our findings motivate future efforts to understand tremor from a perspective that considers neuromechanical coupling within the context of closed-loop control. The strategy of combining experimental recordings with physiologically-sound simulations will enable thorough

  11. Reliability of a novel neurostimulation method to study involuntary muscle phenomena.

    PubMed

    Minetto, Marco Alessandro; Botter, Alberto; Ravenni, Roberta; Merletti, Roberto; De Grandis, Domenico

    2008-01-01

    Experimental methods involving painful electrical stimulation of a peripheral nerve showed the existence of a minimum stimulation frequency capable of inducing cramp, termed "threshold frequency" (TF). Our aim was to test an alternative method to induce fasciculations and cramps electrically. Two daily sessions of electrical stimulation of the abductor hallucis muscle were performed in 19 volunteers on 3 days: stimulation trains of 150 monophasic square pulses (duration 152 micros) of increasing frequency (current intensity 30% higher than maximal; frequency of the first trial, 4 pps; recovery between trials, 1 min) were delivered to the main muscle motor point until a cramp developed. Once a cramp was induced the protocol was repeated after 30 min. To verify by electromyography that cramp occurred, a surface electrode array was placed between the motor point and the distal tendon. Ambient and skin temperature were kept constant in all sessions. Fasciculations and cramps were elicited in all subjects. We observed the following median (interquartile range) values of TF: day 1 (session 1), 13 (6) pps; day 1 (session 2), 16 (4) pps; day 2 (session 1), 16 (6) pps; day 2 (session 2), 18 (6) pps; day 3 (session 1), 17 (4) pps; day 3 (session 2), 18 (8) pps. TF intersession intraclass correlation coefficients were 0.82, 0.92, and 0.90 for days 1, 2, and 3, respectively. TF interday intraclass correlation coefficient was 0.85. The absence of pain due to the stimulation and the demonstration of TF reliability support the use of our method for the study of involuntary muscle phenomena.

  12. Involuntary movements and coma as the prognostic marker for acute encephalopathy with biphasic seizures and late reduced diffusion.

    PubMed

    Lee, Sooyoung; Sanefuji, Masafumi; Torio, Michiko; Kaku, Noriyuki; Ichimiya, Yuko; Mizuguchi, Soichi; Baba, Haruhisa; Sakai, Yasunari; Ishizaki, Yoshito; Torisu, Hiroyuki; Kira, Ryutaro; Hara, Toshiro; Ohga, Shouichi

    2016-11-15

    Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) occurs in children associated with infection. It is characterized by a prolonged febrile seizure in the first phase, and a cluster of seizures, deterioration of consciousness and the white matter lesions with reduced diffusion in the second phase. The patients often have severe neurological sequelae, but the prognostic indicators remain unknown. The present study aimed to clarify the characteristics of AESD patients who subsequently exhibited severe neurological sequelae. We retrospectively analyzed the clinical and laboratory findings along with the brain imaging in patients who had severe (n=8) and non-severe neurodevelopmental outcomes (n=12). Severe group more frequently showed coma (p=0.014) or involuntary movements including dystonia and oral dyskinesia (p=0.018) before the second phase than non-severe group. Severe group exhibited higher levels of serum alanine aminotransferase than non-severe group (p=0.001). Quantitatively assessed MRI in the second phase revealed that severe group had more extensive lesions than non-severe group, in the anterior (p=0.015) and posterior parts (p=0.011) of the cerebrum and basal ganglia (p=0.020). Early appearing involuntary movements or coma might account for the extension of acute brain lesions and the poor neurological outcomes in AESD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Adaptive optics scanning laser ophthalmoscope using liquid crystal on silicon spatial light modulator: Performance study with involuntary eye movement

    NASA Astrophysics Data System (ADS)

    Huang, Hongxin; Toyoda, Haruyoshi; Inoue, Takashi

    2017-09-01

    The performance of an adaptive optics scanning laser ophthalmoscope (AO-SLO) using a liquid crystal on silicon spatial light modulator and Shack-Hartmann wavefront sensor was investigated. The system achieved high-resolution and high-contrast images of human retinas by dynamic compensation for the aberrations in the eyes. Retinal structures such as photoreceptor cells, blood vessels, and nerve fiber bundles, as well as blood flow, could be observed in vivo. We also investigated involuntary eye movements and ascertained microsaccades and drifts using both the retinal images and the aberrations recorded simultaneously. Furthermore, we measured the interframe displacement of retinal images and found that during eye drift, the displacement has a linear relationship with the residual low-order aberration. The estimated duration and cumulative displacement of the drift were within the ranges estimated by a video tracking technique. The AO-SLO would not only be used for the early detection of eye diseases, but would also offer a new approach for involuntary eye movement research.

  14. Identification and classification of involuntary leg muscle contractions in electromyographic records from individuals with spinal cord injury.

    PubMed

    Thomas, C K; Dididze, M; Martinez, A; Morris, R W

    2014-10-01

    Involuntary muscle contractions (spasms) are common after human spinal cord injury (SCI). Our aim was to compare how well two raters independently identified and classified different types of spasms in the same electromyographic records (EMG) using predefined rules. Muscle spasms were identified by the presence, timing and pattern of EMG recorded from paralyzed leg muscles of four subjects with chronic cervical SCI. Spasms were classified as one of five types: unit, tonic, clonus, myoclonus, mixed. In 48h of data, both raters marked the same spasms most of the time. More variability in the total spasm count arose from differences between muscles (84%; within subjects) than differences between subjects (6.5%) or raters (2.6%). Agreement on spasm classification was high (89%). Differences in spasm count, and classification largely occurred when EMG was marked as a single spasm by one rater but split into multiple spasms by the other rater. EMG provides objective measurements of spasm number and type in contrast to the self-reported spasm counts that are often used to make clinical decisions about spasm management. Data on inter-rater agreement and discrepancies on muscle spasm analysis can both drive the design and evaluation of software to automate spasm identification and classification.

  15. The saccadic Stroop effect: Evidence for involuntary programming of eye movements by linguistic cues.

    PubMed

    Hodgson, Timothy L; Parris, Ben A; Gregory, Nicola J; Jarvis, Tracey

    2009-03-01

    The effect of automatic priming of behaviour by linguistic cues is well established. However, as yet these effects have not been directly demonstrated for eye movement responses. We investigated the effect of linguistic cues on eye movements using a modified version of the Stroop task in which a saccade was made to the location of a peripheral colour patch which matched the "ink" colour of a centrally presented word cue. The words were either colour words ("red", "green", "blue", "yellow") or location words ("up", "down", "left", "right"). As in the original version of the Stroop task the identity of the word could be either congruent or incongruent with the response location. The results showed that oculomotor programming was influenced by word identity, even though the written word provided no task relevant information. Saccade latency was increased on incongruent trials and an increased frequency of error saccades was observed in the direction congruent with the word identity. The results argue against traditional distinctions between reflexive and voluntary programming of saccades and suggest that linguistic cues can also influence eye movement programming in an automatic manner.

  16. Involuntary contralateral upper extremity muscle activation pattern during unilateral pinch grip following stroke.

    PubMed

    Seo, Na Jin

    2013-01-01

    Repeated measures design. Mirror activity refers to emergence of motion not only in the intended, but also in the contralateral limb. To characterize post-stroke mirror activities across multiple muscles during unilateral pinch. Chronic stroke survivors performed unilateral pinch grip using the paretic and nonparetic hand, while four muscles' EMGs were recorded for both hands. During the paretic hand grip, the relaxed nonparetic hand showed mirror activity that was more pronounced for the intrinsic (FDI and thenar eminence) than extrinsic muscles (FDS and EDC). During the nonparetic hand grip, mirror activity in the paretic hand was suppressed for the intrinsic than extrinsic muscles. Chronic stroke survivors' relaxed hand did not mirror the task hand's muscle activation pattern, but displayed altered muscle activation patterns depending on muscles and sides, possibly mediated by disturbed interhemispheric inhibition and relative reliance on corticospinal tracts among muscles. N/A. Copyright © 2013 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

  17. Resolving pathobiological mechanisms relating to Huntington disease: gait, balance, and involuntary movements in mice with targeted ablation of striatal D1 dopamine receptor cells.

    PubMed

    Kim, Hyun Ah; Jiang, Luning; Madsen, Heather; Parish, Clare L; Massalas, Jim; Smardencas, Arthur; O'Leary, Claire; Gantois, Ilse; O'Tuathaigh, Colm; Waddington, John L; Ehrlich, Michelle E; Lawrence, Andrew J; Drago, John

    2014-02-01

    Progressive cell loss is observed in the striatum, cerebral cortex, thalamus, hypothalamus, subthalamic nucleus and hippocampus in Huntington disease. In the striatum, dopamine-responsive medium spiny neurons are preferentially lost. Clinical features include involuntary movements, gait and orofacial impairments in addition to cognitive deficits and psychosis, anxiety and mood disorders. We utilized the Cre-LoxP system to generate mutant mice with selective postnatal ablation of D1 dopamine receptor-expressing striatal neurons to determine which elements of the complex Huntington disease phenotype relate to loss of this neuronal subpopulation. Mutant mice had reduced body weight, locomotor slowing, reduced rearing, ataxia, a short stride length wide-based erratic gait, impairment in orofacial movements and displayed haloperidol-suppressible tic-like movements. The mutation was associated with an anxiolytic profile. Mutant mice had significant striatal-specific atrophy and astrogliosis. D1-expressing cell number was reduced throughout the rostrocaudal extent of the dorsal striatum consistent with partial destruction of the striatonigral pathway. Additional striatal changes included up-regulated D2 and enkephalin mRNA, and an increased density of D2 and preproenkephalin-expressing projection neurons, and striatal neuropeptide Y and cholinergic interneurons. These data suggest that striatal D1-cell-ablation alone may account for the involuntary movements and locomotor, balance and orofacial deficits seen not only in HD but also in HD phenocopy syndromes with striatal atrophy. Therapeutic strategies would therefore need to target striatal D1 cells to ameliorate deficits especially when the clinical presentation is dominated by a bradykinetic/ataxic phenotype with involuntary movements.

  18. Parkinson Disease: Treating Symptoms Unrelated to Muscle Movement

    MedlinePlus

    ... FAMILIES PARKINSON DISEASE: TREATING SYMPTOMS UNRELATED TO MUSCLE MOVEMENT This fact sheet may help you understand which ... help Parkinson disease (PD) symptoms unrelated to muscle movement. Neurologists from the American Academy of Neurology are ...

  19. Involuntary reflexive pelvic floor muscle training in addition to standard training versus standard training alone for women with stress urinary incontinence: study protocol for a randomized controlled trial.

    PubMed

    Luginbuehl, Helena; Lehmann, Corinne; Baeyens, Jean-Pierre; Kuhn, Annette; Radlinger, Lorenz

    2015-11-17

    Pelvic floor muscle training is effective and recommended as first-line therapy for female patients with stress urinary incontinence. However, standard pelvic floor physiotherapy concentrates on voluntary contractions even though the situations provoking stress urinary incontinence (for example, sneezing, coughing, running) require involuntary fast reflexive pelvic floor muscle contractions. Training procedures for involuntary reflexive muscle contractions are widely implemented in rehabilitation and sports but not yet in pelvic floor rehabilitation. Therefore, the research group developed a training protocol including standard physiotherapy and in addition focused on involuntary reflexive pelvic floor muscle contractions. The aim of the planned study is to compare this newly developed physiotherapy program (experimental group) and the standard physiotherapy program (control group) regarding their effect on stress urinary incontinence. The working hypothesis is that the experimental group focusing on involuntary reflexive muscle contractions will have a higher improvement of continence measured by the International Consultation on Incontinence Modular Questionnaire Urinary Incontinence (short form), and - regarding secondary and tertiary outcomes - higher pelvic floor muscle activity during stress urinary incontinence provoking activities, better pad-test results, higher quality of life scores (International Consultation on Incontinence Modular Questionnaire) and higher intravaginal muscle strength (digitally tested) from before to after the intervention phase. This study is designed as a prospective, triple-blinded (participant, investigator, outcome assessor), randomized controlled trial with two physiotherapy intervention groups with a 6-month follow-up including 48 stress urinary incontinent women per group. For both groups the intervention will last 16 weeks and will include 9 personal physiotherapy consultations and 78 short home training sessions (weeks 1

  20. The use of the Actiwatch-Neurologica system to objectively assess the involuntary movements and sleep-wake activity in patients with mild-moderate Huntington's disease.

    PubMed

    Hurelbrink, Carrie B; Lewis, Simon J G; Barker, Roger A

    2005-06-01

    Huntington's disease (HD) is a neurodegenerative disorder characterised by cognitive, psychiatric and motor abnormalities including a range of involuntary movements. Currently, assessment of these movements involves the use of subjective rating scales such as the Unified Huntington's Disease Rating Scales (UHDRS) for bradykinesia and maximal dystonia and chorea, without any objective measures. As new therapies emerge, it is critical that an objective means of evaluating these abnormal movements is developed and we have investigated the use of a wrist-worn activity monitor, the Actiwatch-Neurologica, to determine whether these movements can be measured. In addition, this activity monitor and subjective reports were used to objectively measure the degree of sleep disruption in these same HD patients. Eight patients with mild-moderate HD and 8 age- and sex-matched control subjects wore the monitor for a period of 48 hours and recorded in a diary whether they were asleep or awake for each hour over the 2-day period. Assessment of various movement parameters revealed that HD patients exhibited significantly greater total and maximum activity levels and spent longer performing high acceleration movements while they were awake compared with controls. During sleep, patients not only showed significantly more activity and spent more time making high acceleration movements, but they also made significantly more movements than control subjects. These results demonstrate that the Actiwatch-Neurologica activity monitor can be used to objectively assess movements in HD patients during periods of high activity as well as during sleep.

  1. Effect of body posture on involuntary swallow in healthy volunteers.

    PubMed

    Shiino, Yoshitaka; Sakai, Shogo; Takeishi, Ryosuke; Hayashi, Hirokazu; Watanabe, Masahiro; Tsujimura, Takanori; Magara, Jin; Ito, Kayoko; Tsukada, Tetsu; Inoue, Makoto

    2016-03-01

    Clinically, reclining posture has been reported to reduce risk of aspiration. However, during involuntary swallow in reclining posture, changes in orofacial and pharyngeal movement before and during pharyngeal swallow should be considered. Further, the mechanisms underlying the effect of body posture on involuntary swallow remain unclear. The aim of the present study was to determine the effect of body posture on activity patterns of the suprahyoid muscles and on patterns of bolus transport during a natural involuntary swallow. Thirteen healthy male adults participated in a water infusion test and a chewing test. In the water infusion test, thickened water was delivered into the pharynx at a very slow rate until the first involuntary swallow was evoked. In the chewing test, subjects were asked to eat 10 g of gruel rice. In both tests, the recording was performed at four body postures between upright and supine positions. Results showed that reclining changed the location of the bolus head at the start of swallow and prolonged onset latency of the swallowing initiation. Muscle burst duration and whiteout time measured by videoendoscopy significantly increased with body reclining and prolongation of the falling time. In the chewing test, reclining changed the location of the bolus head at the start of swallow, and the frequency of bolus residue after the first swallow increased. Duration and area of EMG burst and whiteout time significantly increased with body reclining. These data suggest that body reclining may result in prolongation of pharyngeal swallow during involuntary swallow. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Reprimed charge movement in skeletal muscle fibres.

    PubMed Central

    Rakowski, R F

    1978-01-01

    1. The three intracellular micro-electrode voltage-clamp technique was used to study the recovery of membrane charge movement in semitendinosus muscles of Rana pipiens. Muscles were placed in a hypertonic depolarizing solution to inactivate voltage dependent charge movement. Tetrodotoxin and tetraethylammonium ions (TEA+) were present to block voltage dependent ionic conductances. Rb+ and SO4(2-) were present to reduce inward rectification and leakage conductance. 2. The recovery ('repriming') of membrane charge movement was studied following hyperpolarizing pulses from a holding potential of -20 mV to membrane potentials from -30 to -140 mV for durations of 2--100 sec. The reprimed charge movement measured as the difference in membrane current required for identical voltage steps before and after long duration hyperpolarizing pulses was a linear function of membrane potential and symmetrical in shape. Reprimed charge is, therefore, simply the result of an increase in the linear capacitance of the fibre. 3. The mean value of the percent increase in capacitance for repriming at -100 mV was 12.3 +/- 1.7% (S.E. of mean) for 25 sec duration pulses and 27.8 +/- 2.9% for 100 sec duration pulses. If these data are corrected to the steady state and the surface contribution subtracted, the mean increase in 'volume' capacity is 40.3 +/- 3.6% (n = 21) for fibres with a mean diameter of 51 +/- 4 micron. 4. The increase in capacity can arise either by an increase in the transverse tubular length constant (lambdaT) or by gaining electrical access to additional linear capacitance within the fibre volume. If the capacitance arises solely from the transverse tubular system, the value of lambdaT before repriming can be no larger than 20 micron in order to explain the observed increase in volume capacity. A value of lambdaT as small as this seems unlikely. 5. The observation that reprimed charge is simply the result of an increase in linear capacitance is not consistent with the

  3. Spontaneous Aching Pain and Peculiar Involuntary Movements: A Case Report of Painful Legs and Moving Toes and Review of the Literature

    PubMed Central

    Fan, Yang-yi; Xu, Yan; Gao, Xu-guang

    2014-01-01

    Painful legs and moving toes (PLMT) is a rare syndrome characterized by spontaneous neuropathic pain and peculiar involuntary movements in the lower limbs, especially the toes and feet. As it is a relatively rare disorder worldwide, the exact pathophysiology still remains a mystery. Until recently, numerous methods of clinical treatments have been tried; however, the success rate of the therapies is still very low. Here, we report a case of PLMT and also summarize the recent clinical and research literatures regarding clinical presentation, electrophysiological features, etiology, treatment methods, and prognosis of this disorder. Doctors should be aware of this rare syndrome in a patient with painful and/or restless legs. On the other hand, multiple clinical treatments should be tried, even those which usually produce a poor outcome. PMID:25530763

  4. Involuntary Outpatient Commitment of the Mentally Ill.

    ERIC Educational Resources Information Center

    Wilk, Ruta J.

    1988-01-01

    Examines the issue of involuntary outpatient commitment, and its implications for social workers working in the health system. Describes a nationwide movement to establish a new system of involuntary outpatient commitment to address the failure of deinstitutionalization, mandating mental health treatment in the community for persons ineligible for…

  5. Activity patterns of leg muscles in periodic limb movement disorder.

    PubMed

    de Weerd, A W; Rijsman, R M; Brinkley, A

    2004-02-01

    The movements of leg muscles in reference to periodic limb movement disorder (PLMD) have only been described in global terms. The sequences of contracting muscles that cause the PLMs are said to be stereotypical. There is, however, doubt about this fixed sequencing in PLMD. Our goal was to define the sequence of muscle movements in PLMs and then analyse their patterns. We recorded with surface EMG all movements of the muscles said to be involved in PLMs (extensor digitorum brevis, EDB; tibialis anterior, TA; biceps femoris, BF; tensor fasciae latae; TFL) as well as the quadriceps (Q) and soleus (S) muscles in 12 patients with restless legs syndrome combined with PLMD. Accompanying polysomnography provided the sleep parameters. In total, 469 movements were analysed. In only 12% was there the appearance of the classic movement (EDB-TA-BF-TFL) or its direct variants. The most frequent sequences were characterised by contraction of only the TA, TA-EDB only, or TA-EDB followed by all other combinations (32%). The pattern EDB only, EDB-TA, or EDB-TA followed by contraction of one or more other muscles, was seen in 18%. All other combinations appeared in much smaller numbers or only once. Eight patients had specific patterns. Three consistently started with the same muscle. One patient always contracted all six muscles. Six patients never contracted more than three muscles. The number of muscles contracted correlated positively with the appearance of arousal from sleep. The interval between onset of contractions within the PLMs varied randomly in a range of 0-1 s. Within PLMs many variations of muscle movements were documented. Patterns were recognisable, individually determined, and related to arousal from sleep.

  6. Patterns of arm muscle activation involved in octopus reaching movements.

    PubMed

    Gutfreund, Y; Flash, T; Fiorito, G; Hochner, B

    1998-08-01

    The extreme flexibility of the octopus arm allows it to perform many different movements, yet octopuses reach toward a target in a stereotyped manner using a basic invariant motor structure: a bend traveling from the base of the arm toward the tip (Gutfreund et al., 1996a). To study the neuronal control of these movements, arm muscle activation [electromyogram (EMG)] was measured together with the kinematics of reaching movements. The traveling bend is associated with a propagating wave of muscle activation, with maximal muscle activation slightly preceding the traveling bend. Tonic activation was occasionally maintained afterward. Correlation of the EMG signals with the kinematic variables (velocities and accelerations) reveals that a significant part of the kinematic variability can be explained by the level of muscle activation. Furthermore, the EMG level measured during the initial stages of movement predicts the peak velocity attained toward the end of the reaching movement. These results suggest that feed-forward motor commands play an important role in the control of movement velocity and that simple adjustment of the excitation levels at the initial stages of the movement can set the velocity profile of the whole movement. A simple model of octopus arm extension is proposed in which the driving force is set initially and is then decreased in proportion to arm diameter at the bend. The model qualitatively reproduces the typical velocity profiles of octopus reaching movements, suggesting a simple control mechanism for bend propagation in the octopus arm.

  7. Effects of Local and Widespread Muscle Fatigue on Movement Timing

    PubMed Central

    Cowley, Jeffrey C.; Dingwell, Jonathan B.; Gates, Deanna H.

    2014-01-01

    Repetitive movements can cause muscle fatigue, leading to motor reorganization, performance deficits, and/or possible injury. The effects of fatigue may depend on the type of fatigue task employed, however. The purpose of this study was to determine how local fatigue of a specific muscle group versus widespread fatigue of various muscle groups affected the control of movement timing. Twenty healthy subjects performed an upper-extremity low-load work task similar to sawing for 5 continuous minutes both before and after completing a protocol that either fatigued all the muscles used in the task (widespread fatigue) or a protocol that selectively fatigued the primary muscles used to execute the pushing stroke of the sawing task (localized fatigue). Subjects were instructed to time their movements with a metronome. Timing error, movement distance, and speed were calculated for each movement. Data were then analyzed using a goal-equivalent manifold (GEM) approach to quantify changes in goal-relevant and non-goal-relevant variability. We applied detrended fluctuation analysis to each time series to quantify changes in fluctuation dynamics that reflected changes in the control strategies used. After localized fatigue, subjects made shorter, slower movements and exerted greater control over non-goal-relevant variability. After widespread fatigue, subjects exerted less control over non-goal-relevant variability and did not change movement patterns. Thus, localized and widespread muscle fatigue affected movement differently. Local fatigue may reduce the available motor solutions and therefore cause greater movement reorganization than widespread muscle fatigue. Subjects altered their control strategies but continued to achieve the timing goal after both fatigue tasks. PMID:25183157

  8. [Nicolaus Steno's geometrical description of muscle: the investigation of muscle movements in the 17th century].

    PubMed

    Anzai, Natsume; Sawai, Tadashi; Sakai, Tatsuo

    2014-03-01

    Famous geologist Nicolaus Steno (1638-1686) was known as a skillful anatomist in his time. His main work about anatomy is "Elementorum myologiae specimen, seu musculi descriptio geometrica". Steno introduced geometrical representation into muscle study. His purpose was to handle muscle movements in the style of Cartesian mechanical philosophy, assuming muscle fibers as the structural and functional unit of muscle. Steno modelled muscles as parallelepiped integrations of fibers. Steno thought the shortening of muscle fibers modified parallelepiped integration and its modification resulted in muscle movements. His parallelepiped model enabled the regarding of muscles as objects of physics. Steno's assumption and model built a methodological foundation of mechanistic physiology of muscle, and influenced latter 17th century thinkers, especially Borelli.

  9. Cognitive constraint on the 'automatic pilot' for the hand: movement intention influences the hand's susceptibility to involuntary online corrections.

    PubMed

    Cameron, Brendan D; Cressman, Erin K; Franks, Ian M; Chua, Romeo

    2009-09-01

    Research suggests that the reaching hand automatically deviates toward a target that changes location (jumps) during the reach. In the current study, we investigated whether movement intention can influence the target jump's impact on the hand. We compared the degree of trajectory deviation to a jumped target under three instruction conditions: (1) GO, in which participants were told to go to the target if it jumped, (2) STOP, in which participants were told to immediately stop their movement if the target jumped, and (3) IGNORE, in which participants were told to ignore the target if it jumped and to continue to its initial location. We observed a reduced response to the jump in the IGNORE condition relative to the other conditions, suggesting that the response to the jump is contingent on the jump being a task-relevant event.

  10. Improving mouse controlling and movement for people with Parkinson's disease and involuntary tremor using adaptive path smoothing technique via B-spline.

    PubMed

    Hashem, Seyed Yashar Bani; Zin, Nor Azan Mat; Yatim, Noor Faezah Mohd; Ibrahim, Norlinah Mohamed

    2014-01-01

    Many input devices are available for interacting with computers, but the computer mouse is still the most popular device for interaction. People who suffer from involuntary tremor have difficulty using the mouse in the normal way. The target participants of this research were individuals who suffer from Parkinson's disease. Tremor in limbs makes accurate mouse movements impossible or difficult without any assistive technologies to help. This study explores a new assistive technique-adaptive path smoothing via B-spline (APSS)-to enhance mouse controlling based on user's tremor level and type. APSS uses Mean filtering and B-spline to provide a smoothed mouse trajectory. Seven participants who have unwanted tremor evaluated APSS. Results show that APSS is very promising and greatly increases their control of the computer mouse. Result of user acceptance test also shows that user perceived APSS as easy to use. They also believe it to be a useful tool and intend to use it once it is available. Future studies could explore the possibility of integrating APSS with one assistive pointing technique, such as the Bubble cursor or the Sticky target technique, to provide an all in one solution for motor disabled users.

  11. The H3 receptor agonist immepip does not affect l-dopa-induced abnormal involuntary movements in 6-OHDA-lesioned rats.

    PubMed

    Papathanou, Maria; Jenner, Peter; Iravani, Mahmoud; Jackson, Michael; Stockwell, Kim; Strang, Isabel; Zeng, Bai-Yun; McCreary, Andrew C; Rose, Sarah

    2014-10-15

    The treatment of dyskinesia in Parkinson׳s disease remains poor but H3 receptor agonists have been suggested as a novel pharmacological approach. We examined the effects of the H3 agonist, immepip, in 6-OHDA-lesioned rats exhibiting AIMs (abnormal involuntary movements), a rat analogue of dyskinesia, in response to l-dopa compared to the known anti-dyskinetic agents amantadine, MK-801 and 8-OHDPAT. We then attempted to extend these studies in to dyskinetic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treated common marmosets. Amantadine, MK-801 and 8-OHDPAT all dose-dependently reduced l-dopa-induced axial, lingual and oral (ALO) AIMs in 6-OHDA-lesioned animals accompanied by a reduction in contralateral rotation with higher doses of amantadine and MK-801. By contrast, immepip had no effect on AIMs expression or contralateral rotation. In the MPTP-treated common marmoset exhibiting dyskinesia to l-dopa, immepip alone induced retching and in combination with l-dopa administered subcutaneously or orally induced the rapid onset of retching and vomiting which was not controlled by pretreatment with domperidone. Administration of the unrelated H3 agonist, imetit had the same effect. Despite causing negative side-effects, it appears that both agonists reduced the antiparkinsonian response to l-dopa resulting in reduced dyskinesia. H3 agonists appear unlikely candidates for the treatment of dyskinesia in PD based on lack of evidence of efficacy and potential adverse effects.

  12. Proximal and distal muscle fatigue differentially affect movement coordination

    PubMed Central

    Cowley, Jeffrey C.

    2017-01-01

    Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor) or distal (finger flexor) muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p < 0.005) in trunk lean and velocity, reduced humeral elevation (11°, p < 0.005), and increased elbow flexion (4°, p < 0.01). In contrast, distal fatigue caused small but significant changes in trunk angles (2°, p < 0.05), increased velocity of wrench movement relative to the hand (17°/s, p < 0.001), and earlier wrist extension (4%, p < 0.005). Movement variability increased at proximal joints but not distal joints after both fatigue protocols (p < 0.05). Varying movements at proximal joints may help people adapt to fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks. PMID:28235005

  13. Proximal and distal muscle fatigue differentially affect movement coordination.

    PubMed

    Cowley, Jeffrey C; Gates, Deanna H

    2017-01-01

    Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor) or distal (finger flexor) muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p < 0.005) in trunk lean and velocity, reduced humeral elevation (11°, p < 0.005), and increased elbow flexion (4°, p < 0.01). In contrast, distal fatigue caused small but significant changes in trunk angles (2°, p < 0.05), increased velocity of wrench movement relative to the hand (17°/s, p < 0.001), and earlier wrist extension (4%, p < 0.005). Movement variability increased at proximal joints but not distal joints after both fatigue protocols (p < 0.05). Varying movements at proximal joints may help people adapt to fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks.

  14. Timing of Cortico-Muscle Transmission During Active Movement.

    PubMed

    Van Acker, Gustaf M; Luchies, Carl W; Cheney, Paul D

    2016-08-01

    Numerous studies have reported large disparities between short cortico-muscle conduction latencies and long recorded delays between cortical firing and evoked muscle activity. Using methods such as spike- and stimulus-triggered averaging of electromyographic (EMG) activity, previous studies have shown that the time delay between corticomotoneuronal (CM) cell firing and onset of facilitation of forelimb muscle activity ranges from 6.7 to 9.8 ms, depending on the muscle group tested. In contrast, numerous studies have reported delays of 60-122 ms between cortical cell firing onset and either EMG or movement onset during motor tasks. To further investigate this disparity, we simulated rapid active movement by applying frequency-modulated stimulus trains to M1 cortical sites in a rhesus macaque performing a movement task. This yielded corresponding EMG modulations, the latency of which could be measured relative to the stimulus modulations. The overall mean delay from stimulus frequency modulation to EMG modulation was 11.5 ± 5.6 ms, matching closely the conduction time through the cortico-muscle pathway (12.6 ± 2.0 ms) derived from poststimulus facilitation peaks computed at the same sites. We conclude that, during active movement, the delay between modulated M1 cortical output and its impact on muscle activity approaches the physical cortico-muscle conduction time.

  15. The Movement of Thallium Ions in Muscle

    PubMed Central

    Mullins, L. J.; Moore, R. D.

    1960-01-01

    Measurements have been made of the fluxes of thallous ions (Tl+) across the membrane of frog sartorius muscle fibers. These show that at an external concentration of 74 µM the influx is about 270 x 10-15 moles/cm.2 sec., while the efflux from a muscle with an internal concentration equal to the above is 5 x 10-15 moles/cm.2 sec. The efflux is increased of the order of 300-fold during a muscle twitch, and Tl+ reach a steady-state distribution between fiber water and Ringer solution that is very close to the corresponding ratio for K+. High concentrations of Tl+ depolarize the membrane about 58 mv. for a tenfold increase in external concentration. The results obtained are consistent with the view that the muscle fiber membrane cannot distinguish between the toxic heavy metal Tl+ and K+, provided that the concentrations of the former ion are kept low. High concentrations of Tl+, if allowed to act for an appreciable period of time, lead to irreversible damage to muscle. PMID:14425196

  16. A computational model for optimal muscle activity considering muscle viscoelasticity in wrist movements

    PubMed Central

    Shin, Duk; Koike, Yasuharu

    2013-01-01

    To understand the mechanism of neural motor control, it is important to clarify how the central nervous system organizes the coordination of redundant muscles. Previous studies suggested that muscle activity for step-tracking wrist movements are optimized so as to reduce total effort or end-point variance under neural noise. However, since the muscle dynamics were assumed as a simple linear system, some characteristic patterns of experimental EMG were not seen in the simulated muscle activity of the previous studies. The biological muscle is known to have dynamic properties in which its elasticity and viscosity depend on activation level. The motor control system is supposed to consider the viscoelasticity of the muscles when generating motor command signals. In this study, we present a computational motor control model that can control a musculoskeletal system with nonlinear dynamics. We applied the model to step-tracking wrist movements actuated by five muscles with dynamic viscoelastic properties. To solve the motor redundancy, we designed the control model to generate motor commands that maximize end-point accuracy under signal-dependent noise, while minimizing the squared sum of them. Here, we demonstrate that the muscle activity simulated by our model exhibits spatiotemporal features of experimentally observed muscle activity of human and nonhuman primates. In addition, we show that the movement trajectories resulting from the simulated muscle activity resemble experimentally observed trajectories. These results suggest that, by utilizing inherent viscoelastic properties of the muscles, the neural system may optimize muscle activity to improve motor performance. PMID:23324321

  17. Muscle-driven finite element simulation of human foot movements.

    PubMed

    Spyrou, L A; Aravas, N

    2012-01-01

    This paper describes a finite element scheme for realistic muscle-driven simulation of human foot movements. The scheme is used to simulate human ankle plantar flexion. A three-dimensional anatomically detailed finite element model of human foot and lower leg is developed and the idea of generating natural foot movement based entirely on the contraction of the plantar flexor muscles is used. The bones, ligaments, articular cartilage, muscles, tendons, as well as the rest soft tissues of human foot and lower leg are included in the model. A realistic three-dimensional continuum constitutive model that describes the biomechanical behaviour of muscles and tendons is used. Both the active and passive properties of muscle tissue are accounted for. The materials for bones and ligaments are considered as homogeneous, isotropic and linearly elastic, whereas the articular cartilage and the rest soft tissues (mainly fat) are defined as hyperelastic materials. The model is used to estimate muscle tissue deformations as well as stresses and strains that develop in the lower leg muscles during plantar flexion of the ankle. Stresses and strains that develop in Achilles tendon during such a movement are also investigated.

  18. Induction and expression of abnormal involuntary movements is related to the duration of dopaminergic stimulation in 6-OHDA-lesioned rats.

    PubMed

    Papathanou, Maria; Rose, Sarah; McCreary, Andrew; Jenner, Peter

    2011-06-01

    Dyskinesia induction in Parkinson's disease (PD) appears less marked with long-acting dopamine agonists than with short-acting L-Dopa, but the relationship to duration of drug action is unknown. It is also unclear whether the duration of drug action affects the expression of established dyskinesia. This study compared the ability of L-Dopa and four dopamine agonists of different duration of action to induce abnormal involuntary movements (AIMs) in 6-hydroxydopamine (6-OHDA)-lesioned rats, and their ability to express established AIMs following prior exposure to L-Dopa. 6-OHDA-lesioned rats were treated with saline, L-Dopa/benserazide, apomorphine, ropinirole, pramipexole or pergolide once daily for 15 days. Repeated administration of the short-acting dopamine agonists, apomorphine (duration 80 min) and ropinirole (duration 90 min) induced marked axial, limb and orolingual AIMs at peak effect. L-Dopa (duration 100 min) produced moderate AIMs at peak effect, while administration of the long-acting dopamine agonists, pramipexole (duration 150 min) and pergolide (duration 240 min) resulted in mild AIMs. In rats primed to exhibit severe AIMs following repeated L-Dopa administration, acute administration of apomorphine, ropinirole and L-Dopa induced severe AIMs. By contrast, pramipexole and pergolide evoked only mild-moderate AIMs. Again, there was a negative correlation between duration of effect and the severity of AIMs expressed. These studies show that both the induction and expression of AIMs in 6-OHDA-lesioned rats are related to the duration of action of dopaminergic drugs. These findings suggest that continuous dopaminergic stimulation could be used both to avoid dyskinesia induction and to improve motor function in late-stage PD when troublesome dyskinesia is evident.

  19. Early deactivation of slower muscle fibres at high movement frequencies.

    PubMed

    Blake, Ollie M; Wakeling, James M

    2014-10-01

    Animals produce rapid movements using fast cyclical muscle contractions. These types of movements are better suited to faster muscle fibres within muscles of mixed fibre types as they can shorten at faster velocities and achieve higher activation-deactivation rates than their slower counterparts. Preferential recruitment of faster muscle fibres has previously been shown during high velocity contractions. Additionally, muscle deactivation takes longer than activation and therefore may pose a limitation to fast cyclical contractions. It has been speculated that slower fibres may be deactivated before faster fibres to accommodate their longer deactivation time. This study aimed to test whether shifts in muscle fibre recruitment occur with derecruitment of slow fibres before faster fibres at high cycle frequencies. Electromyographic (EMG) signals were collected from the medial gastrocnemius at an extreme range of cycle frequencies and workloads. Wavelets were used to resolve the EMG signals into time and frequency space and the primary sources of variability within the EMG frequency spectra were identified through principal component analysis. Early derecruitment of slower fibres was evident at the end of muscle excitation at higher cycle frequencies, as determined by reduced low-frequency EMG content, and additional slower fibre recruitment was present at the highest cycle frequency. The duration of muscle excitation reached a minimum of about 150 ms and did not change for the three highest cycle frequencies, suggesting a duration limit for the medial gastrocnemius. This study provides further evidence of modifications of muscle fibre recruitment strategies to meet the mechanical demands of movement. © 2014. Published by The Company of Biologists Ltd.

  20. The effect of involuntary motor activity on myoelectric pattern recognition: a case study with chronic stroke patients

    NASA Astrophysics Data System (ADS)

    Zhang, Xu; Li, Yun; Chen, Xiang; Li, Guanglin; Zev Rymer, William; Zhou, Ping

    2013-08-01

    Objective. This study investigates the effect of the involuntary motor activity of paretic-spastic muscles on the classification of surface electromyography (EMG) signals. Approach. Two data collection sessions were designed for 8 stroke subjects to voluntarily perform 11 functional movements using their affected forearm and hand at relatively slow and fast speeds. For each stroke subject, the degree of involuntary motor activity present in the voluntary surface EMG recordings was qualitatively described from such slow and fast experimental protocols. Myoelectric pattern recognition analysis was performed using different combinations of voluntary surface EMG data recorded from the slow and fast sessions. Main results. Across all tested stroke subjects, our results revealed that when involuntary surface EMG is absent or present in both the training and testing datasets, high accuracies (>96%, >98%, respectively, averaged over all the subjects) can be achieved in the classification of different movements using surface EMG signals from paretic muscles. When involuntary surface EMG was solely involved in either the training or testing datasets, the classification accuracies were dramatically reduced (<89%, <85%, respectively). However, if both the training and testing datasets contained EMG signals with the presence and absence of involuntary EMG interference, high accuracies were still achieved (>97%). Significance. The findings of this study can be used to guide the appropriate design and implementation of myoelectric pattern recognition based systems or devices toward promoting robot-aided therapy for stroke rehabilitation.

  1. The Effect of Involuntary Motor Activity on Myoelectric Pattern Recognition: A Case Study with Chronic Stroke Patients

    PubMed Central

    Zhang, Xu; Li, Yun; Chen, Xiang; Li, Guanglin; Rymer, William Zev; Zhou, Ping

    2013-01-01

    This study investigates the effect of involuntary motor activity of paretic-spastic muscles on classification of surface electromyography (EMG) signals. Two data collection sessions were designed for 8 stroke subjects to voluntarily perform 11 functional movements using their affected forearm and hand at a relatively slow and fast speed. For each stroke subject, the degree of involuntary motor activity present in voluntary surface EMG recordings was qualitatively described from such slow and fast experimental protocols. Myoelectric pattern recognition analysis was performed using different combinations of voluntary surface EMG data recorded from slow and fast sessions. Across all tested stroke subjects, our results revealed that when involuntary surface EMG was absent or present in both training and testing datasets, high accuracies (> 96%, > 98%, respectively, averaged over all the subjects) can be achieved in classification of different movements using surface EMG signals from paretic muscles. When involuntary surface EMG was solely involved in either training or testing datasets, the classification accuracies were dramatically reduced (< 89%, < 85%, respectively). However, if both training and testing datasets contained EMG signals with presence and absence of involuntary EMG interference, high accuracies were still achieved (> 97%). The findings of this study can be used to guide appropriate design and implementation of myoelectric pattern recognition based systems or devices toward promoting robot-aided therapy for stroke rehabilitation. PMID:23860192

  2. Speech Motor Development: Integrating Muscles, Movements, and Linguistic Units

    ERIC Educational Resources Information Center

    Smith, Anne

    2006-01-01

    A fundamental problem for those interested in human communication is to determine how ideas and the various units of language structure are communicated through speaking. The physiological concepts involved in the control of muscle contraction and movement are theoretically distant from the processing levels and units postulated to exist in…

  3. Speech Motor Development: Integrating Muscles, Movements, and Linguistic Units

    ERIC Educational Resources Information Center

    Smith, Anne

    2006-01-01

    A fundamental problem for those interested in human communication is to determine how ideas and the various units of language structure are communicated through speaking. The physiological concepts involved in the control of muscle contraction and movement are theoretically distant from the processing levels and units postulated to exist in…

  4. Refined distribution of myelinated trigeminal proprioceptive nerve fibres in Mueller's muscle as the mechanoreceptors to induce involuntary reflexive contraction of the levator and frontalis muscles.

    PubMed

    Yuzuriha, Shunsuke; Matsuo, Kiyoshi; Hirasawa, Chihiro; Moriizumi, Tetsuji

    2009-11-01

    Stretching of mechanoreceptors in Mueller's muscle induces reflexive contraction of not only the levator muscle but also the frontalis muscle as two different eyelid-opening muscles. Previously, we reported that fine neural myelinated structures, acting as mechanoreceptors, were found in the proximal Mueller's muscle. Since there is a risk of misunderstanding that the middle and distal Mueller's muscle does not contain mechanoreceptors and can be invalidated or resected, the accurate distribution of myelinated trigeminal proprioceptive nerve fibres as mechanoreceptors in Mueller's muscle was refined horizontally in this study. We explored 10 whole Mueller's muscles between the levator muscle and the tarsus of the upper eyelids obtained from five Japanese cadavers. The specimens were serially sliced along the horizontal plane and stained with HE, S-100 protein to determine the presence of Schwann cells, and smooth muscle actin antibody to determine the presence of Mueller's smooth muscle fibres. Although all myelinated nerve fibres in the intermuscular connective tissues among the sympathetically innervated Mueller's multi-unit smooth muscle fibres may not correspond to the proprioceptive nerve fibres, the nerve bundles consisting of multiple myelinated nerve fibres were well distributed in the proximal Mueller's muscle, and single myelinated nerve fibres were well distributed in the middle and distal Mueller's muscle. We believe that the mechanoreceptors in Mueller's muscle consist of myelinated proprioceptive nerve fibres with nerve endings possibly attached to collagen fibres in the intermuscular connective tissues present among Mueller's smooth muscle fibres. As the myelinated nerve fibres innervate the middle and distal Mueller's muscle to a greater extent than those in the proximal Mueller's muscle, the former may be more important as mechanoreceptors than the latter and should not be invalidated or excised during surgery for treatment of blepharoptosis to

  5. Calcium movement of sarcoplasmic reticulum from hindlimb suspended muscle

    NASA Astrophysics Data System (ADS)

    Yoshioka, Toshitada; Shirota, Takuhiko; Tazoe, Takashi; Yamashita-Goto, Katsumasa

    1996-02-01

    The function of the sarcoplasmic reticulum (SR) was examined in the slow soleus and fast extensor digitorum longus (EDL) muscles of rats submitted to 14 days of weightlessness produced by hindlimb suspension (HS). Ca 2+ uptake, Ca 2+ release and passive Ca 2+ leakage through the SR membrane were investigated using a method of caffeine-induced contracture on the single mechanically skinned fibers. In the SR of suspended soleus muscles, the rate of Ca 2+ uptake was higher than in the control muscles. However, there was no difference between the suspended and control muscles in the rate of Ca 2+ uptake of the SR in EDL after HS. In soleus muscles, Ca 2+ movements of the SR from the suspended muscle acquired the properties that were similar to those of the control fast muscle. The study of Ca 2+ leakage showed that the velocity and amount of passive Ca 2+ leakage from SR in soleus and EDL were apparently increased after HS. The results suggested that the functional properties of the SR membrane in slow and fast muscles were changed after HS.

  6. The differential effects of 5-HT(1A) receptor stimulation on dopamine receptor-mediated abnormal involuntary movements and rotations in the primed hemiparkinsonian rat.

    PubMed

    Dupre, Kristin B; Eskow, Karen L; Negron, Giselle; Bishop, Christopher

    2007-07-16

    Serotonin 1A receptor (5-HT(1A)R) agonists have emerged as valuable supplements to l-DOPA therapy, demonstrating that they can decrease side effects and enhance motor function in animal models of Parkinson's disease (PD) and human PD patients. The precise mechanism by which these receptors act remains unknown and there is limited information on how 5-HT(1A)R stimulation impacts striatal dopamine (DA) D1 receptor (D1R) and D2 receptor (D2R) function. The current study examined the effects of 5-HT(1A)R stimulation on DA receptor-mediated behaviors. Male Sprague-Dawley rats were rendered hemiparkinsonian by unilateral 6-OHDA lesions and primed with the D1R agonist SKF81297 (0.8 mg/kg, i.p.) in order to sensitize DA receptors. Using a randomized within subjects design, rats received a first injection of: Vehicle (dH(2)O) or the 5-HT(1A)R agonist +/-8-OH-DPAT (0.1 or 1.0 mg/kg, i.p.), followed by a second injection of: Vehicle (dimethyl sulfoxide), the D1R agonist SKF81297 (0.8 mg/kg, i.p.), the D2R agonist quinpirole (0.2 mg/kg, i.p.), or l-DOPA (12 mg/kg+benserazide, 15 mg/kg, i.p.). On test days, rats were monitored over a 2-h period immediately following the second injection for abnormal involuntary movements (AIMs), analogous to dyskinesia observed in PD patients, and contralateral rotations. The present findings indicate that 5-HT(1A)R stimulation reduces AIMs induced by D1R, D2R and l-DOPA administration while its effects on DA agonist-induced rotations were receptor-dependent, suggesting that direct 5-HT(1A)R and DA receptor interactions may contribute to the unique profile of 5-HT(1A)R agonists for the improvement of PD treatment.

  7. Electrical stimulation to the trigeminal proprioceptive fibres that innervate the mechanoreceptors in Müller's muscle induces involuntary reflex contraction of the frontalis muscles.

    PubMed

    Matsuo, Kiyoshi; Osada, Yoshiro; Ban, Ryokuya

    2013-02-01

    The levator and frontalis muscles lack interior muscle spindles, despite consisting of slow-twitch fibres that involuntarily sustain eyelid-opening and eyebrow-raising against gravity. To compensate for this anatomical defect, this study hypothetically proposes that initial voluntary contraction of the levator fast-twitch muscle fibres stretches the mechanoreceptors in Müller's muscle and evokes proprioception, which continuously induces reflex contraction of slow-twitch fibres of the levator and frontalis muscles. This study sought to determine whether unilateral transcutaneous electrical stimulation to the trigeminal proprioceptive fibres that innervate the mechanoreceptors in Müller's muscle could induce electromyographic responses in the frontalis muscles, with monitoring responses in the orbicularis oculi muscles. The study population included 27 normal subjects and 23 subjects with aponeurotic blepharoptosis, who displayed persistently raised eyebrows on primary gaze and light eyelid closure. The stimulation induced a short-latency response in the ipsilateral frontalis muscle of all subjects and long-latency responses in the bilateral frontalis muscles of normal subjects. However, it did not induce long-latency responses in the bilateral frontalis muscles of subjects with aponeurotic blepharoptosis. The orbicularis oculi muscles showed R1 and/or R2 responses. The stimulation might reach not only the proprioceptive fibres, but also other sensory fibres related to the blink or corneal reflex. The experimental system can provoke a monosynaptic short-latency response in the ipsilateral frontalis muscle, probably through the mesencephalic trigeminal proprioceptive neuron and the frontalis motor neuron, and polysynaptic long-latency responses in the bilateral frontalis muscles through an unknown pathway. The latter neural circuit appeared to be engaged by the circumstances of aponeurotic blepharoptosis.

  8. Coupling between muscle activities and muscle torques during horizontal-planar arm movements with direction reversal.

    PubMed

    Almeida, G L; Freitas, S M S F; Marconi, N F

    2006-06-01

    In this study we investigated the hypothesis that the simple set of rules used to explain the modulation of muscle activities during single-joint movements could also be applied for reversal movements of the shoulder and elbow joints. The muscle torques of both joints were characterized by a triphasic impulse. The first impulse of each joint accelerated the limb to the target and was generated by an initial burst of the muscles activated first (primary mover). The second impulse decelerated the limb to the target, reversed movement direction and accelerated the limb back to the initial position, and was generated by an initial burst of the muscles activated second (secondary movers). A third impulse, in each joint, decelerated the limb to the initial position due to the generation of a second burst of the primary movers. The first burst of the primary mover decreased abruptly, and the latency between the activation of the primary and secondary movers varied in proportion with target distances for the elbow, but not for the shoulder muscles. All impulses and bursts increased with target distances and were well coupled. Therefore, as predicted, the bursts of muscle activities were modulated to generate the appropriate level of muscle torque.

  9. A method for studying jaw muscle activity during standardized jaw movements under experimental jaw muscle pain.

    PubMed

    Sae-Lee, Daraporn; Wanigaratne, Kamal; Whittle, Terry; Peck, Christopher C; Murray, Greg M

    2006-10-30

    This paper describes a method for studying superficial and deep jaw muscle activity during standardized jaw movements under experimental jaw muscle pain. In 22 healthy adults, pain was elicited in the right masseter muscle via tonic infusion of 4.5% hypertonic saline and which resulted in scores of 30-60 mm on a 100-mm visual analogue scale. Subjects performed tasks in five sessions in a repeated measures design, i.e., control 1, test 1 (during hypertonic or isotonic saline infusion), control 2 (without infusion), test 2 (during isotonic or hypertonic saline infusion), control 3 (without infusion). During each session, subjects performed maximal clenching and standardized jaw tasks, i.e., protrusion, lateral excursion, open/close, chewing. Mandibular movement was recorded with a 6-degree-of-freedom tracking system simultaneously with electromyographic (EMG) activity from the inferior head of the lateral pterygoid muscle with fine-wire electrodes (verified by computer tomography), and from posterior temporalis, the submandibular muscle group and bilateral masseter muscles with surface electrodes. EMG root mean square values were calculated at each 0.5 mm increment of mandibular incisor movement for all tasks under each experimental session. This establishes an experimental model for testing the effects of pain on jaw muscle activity where the jaw motor system is required to perform goal-directed tasks, and therefore should extend our understanding of the effects of pain on the jaw motor system.

  10. Microtubule motors involved in nuclear movement during skeletal muscle differentiation.

    PubMed

    Gache, V; Gomes, E R; Cadot, B

    2017-04-01

    Nuclear positioning is a determining event in several cellular processes, such as fertilization, cell migration, and cell differentiation. The structure and function of muscle cells, which contain hundreds of nuclei, have been shown to rely in part on proper nuclear positioning. Remarkably, in the course of muscle differentiation, nuclear movements along the myotube axis might represent the event required for the even positioning of nuclei in the mature myofiber. Here we analyze nuclear behavior, time in motion, speed, and alignment during myotube differentiation and temporal interference of cytoskeletal microtubule-related motors. Using specific inhibitors, we find that nuclear movement and alignment are microtubule dependent, with 19 microtubule motor proteins implicated in at least one nuclear behavior. We further focus on Kif1c, Kif5b, kif9, kif21b, and Kif1a, which affect nuclear alignment. These results emphasize the different roles of molecular motors in particular mechanisms.

  11. Cyclic movement frequency is associated with muscle typology in athletes.

    PubMed

    Bex, T; Baguet, A; Achten, E; Aerts, P; De Clercq, D; Derave, W

    2017-02-01

    There is a continuing research interest in the muscle fiber type composition (MFTC) of athletes. Recently, muscle carnosine quantification by proton magnetic resonance spectroscopy ((1) H-MRS) was developed as a new non-invasive method to estimate MFTC. This cross-sectional study aims to better understand estimated MFTC in relation to (a) different disciplines within one sport; (b) cyclic sport exercise characteristics; (c) within-athlete variability; and (d) athlete level. A total of 111 elite athletes (74 runners, 7 triathletes, 11 swimmers, 14 cyclists and 5 kayakers) and 188 controls were recruited to measure muscle carnosine in gastrocnemius and deltoid muscle by (1) H-MRS. Within sport disciplines, athletes were divided into subgroups (sprint-, intermediate-, and endurance-type). The controls were used as reference population to allow expression of the athletes' data as Z-scores. Within different sports, endurance-type athletes systematically showed the lowest Z-score compared to sprint-type athletes, with intermediate-type athletes always situated in between. Across the different sports disciplines, carnosine content showed the strongest significant correlation with cyclic movement frequency (R = 0.86, P = 0.001). Both within and between different cyclic sports, estimated MFTC was divergent between sprint- and endurance-type athletes. Cyclic movement frequency, rather than exercise duration came out as the most determining factor for the optimal estimated MFTC in elite athletes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Tonic central and sensory stimuli facilitate involuntary air-stepping in humans.

    PubMed

    Selionov, V A; Ivanenko, Y P; Solopova, I A; Gurfinkel, V S

    2009-06-01

    Air-stepping can be used as a model for investigating rhythmogenesis and its interaction with sensory input. Here we show that it is possible to entrain involuntary rhythmic movement patterns in healthy humans by using different kinds of stimulation techniques. The subjects lay on their sides with one or both legs suspended, allowing low-friction horizontal rotation of the limb joints. To evoke involuntary stepping of the suspended leg, either we used continuous muscle vibration, electrical stimulation of the superficial peroneal or sural nerves, the Jendrassik maneuver, or we exploited the postcontraction state of neuronal networks (Kohnstamm phenomenon). The common feature across all stimulations was that they were tonic. Air-stepping could be elicited by most techniques in about 50% of subjects and involved prominent movements at the hip and the knee joint (approximately 40-70 degrees). Typically, however, the ankle joint was not involved. Minimal loading forces (4-25 N) applied constantly to the sole (using a long elastic cord) induced noticeable (approximately 5-20 degrees) ankle-joint-angle movements. The aftereffect of a voluntary long-lasting (30-s) contraction in the leg muscles featured alternating rhythmic leg movements that lasted for about 20-40 s, corresponding roughly to a typical duration of the postcontraction activity in static conditions. The Jendrassik maneuver per se did not evoke air-stepping. Nevertheless, it significantly prolonged rhythmic leg movements initiated manually by an experimenter or by a short (5-s) period of muscle vibration. Air-stepping of one leg could be evoked in both forward and backward directions with frequent spontaneous transitions, whereas involuntary alternating two-legged movements were more stable (no transitions). The hypothetical role of tonic influences, contact forces, and bilateral coordination in rhythmogenesis is discussed. The results overall demonstrated that nonspecific tonic drive may cause air

  13. Muscle Cramps

    MedlinePlus

    Muscle cramps are sudden, involuntary contractions or spasms in one or more of your muscles. They often occur after exercise or at night, ... to several minutes. It is a very common muscle problem. Muscle cramps can be caused by nerves ...

  14. TNFα decreases mitochondrial movement in human airway smooth muscle.

    PubMed

    Delmotte, Philippe; Zavaletta, Vanessa A; Thompson, Michael A; Prakash, Y S; Sieck, Gary C

    2017-07-01

    In airway smooth muscle (ASM) cells, excitation-contraction coupling is accomplished via a cascade of events that connect an elevation of cytosolic Ca(2+) concentration ([Ca(2+)]cyt) with cross-bridge attachment and ATP-consuming mechanical work. Excitation-energy coupling is mediated by linkage of the elevation of [Ca(2+)]cyt to an increase in mitochondrial Ca(2+) concentration, which in turn stimulates ATP production. Proximity of mitochondria to the sarcoplasmic reticulum (SR) and plasma membrane is thought to be an important mechanism to facilitate mitochondrial Ca(2+) uptake. In this regard, mitochondrial movement in ASM cells may be key in establishing proximity. Mitochondria also move where ATP or Ca(2+) buffering is needed. Mitochondrial movement is mediated through interactions with the Miro-Milton molecular complex, which couples mitochondria to kinesin motors at microtubules. We examined mitochondrial movement in human ASM cells and hypothesized that, at basal [Ca(2+)]cyt levels, mitochondrial movement is necessary to establish proximity of mitochondria to the SR and that, during the transient increase in [Ca(2+)]cyt induced by agonist stimulation, mitochondrial movement is reduced, thereby promoting transient mitochondrial Ca(2+) uptake. We further hypothesized that airway inflammation disrupts basal mitochondrial movement via a reduction in Miro and Milton expression, thereby disrupting the ability of mitochondria to establish proximity to the SR and, thus, reducing transient mitochondrial Ca(2+) uptake during agonist activation. The reduced proximity of mitochondria to the SR may affect establishment of transient "hot spots" of higher [Ca(2+)]cyt at the sites of SR Ca(2+) release that are necessary for mitochondrial Ca(2+) uptake via the mitochondrial Ca(2+) uniporter. Copyright © 2017 the American Physiological Society.

  15. Role of body size in the relation between muscle strength and movement performance.

    PubMed

    Jaric, Slobodan

    2003-01-01

    Body size relates differently on the outcome of various tests of muscle strength and movement performance. Thus the estimation of functional performance from tests of muscle strength, and vice versa, should be based on the normalization of both muscle strength and movement performance.

  16. Posterior scissors-bite: masticatory jaw movement and muscle activity.

    PubMed

    Tomonari, H; Kubota, T; Yagi, T; Kuninori, T; Kitashima, F; Uehara, S; Miyawaki, S

    2014-04-01

    Scissors-bite is a malocclusion characterised by buccal inclination or buccoversion of the maxillary posterior tooth and/or linguoclination or linguoversion of the mandibular posterior tooth. This type of malocclusion causes reduced contact of the occlusal surfaces and can cause excessive vertical overlapping of the posterior teeth. This case-control study is the first to evaluate both masticatory jaw movement and masseter and temporalis muscle activity in patients with unilateral posterior scissors-bite. Jaw movement variables and surface electromyography data were recorded in 30 adult patients with unilateral posterior scissors-bite malocclusion and 18 subjects with normal occlusion in a case-control study. The chewing pattern on the scissors-bite side significantly differed from that of the non-scissors-bite side in the patients and of the right side in the normal subjects. These differences included a narrower chewing pattern (closing angle, P < 0.01; cycle width, P < 0.01), a longer closing duration (P < 0.05), a slower closing velocity (P < 0.01) and lower activities of both the temporalis (P < 0.05) and the masseter (P < 0.05) muscles on the working side. In 96% of the patients with unilateral posterior scissors-bite, the preferred chewing side was the non-scissors-bite side (P = 0.005). These findings suggest that scissors-bite malocclusion is associated with the masticatory chewing pattern and muscle activity, involving the choice of the preferred chewing side in patients with unilateral posterior scissors-bite.

  17. DEFINITION AND CLASSIFICATION OF HYPERKINETIC MOVEMENTS IN CHILDHOOD

    PubMed Central

    Sanger, Terence D.; Chen, Daofen; Fehlings, Darcy L.; Hallett, Mark; Lang, Anthony E.; Mink, Jonathan W.; Singer, Harvey; Alter, Katharine; Ben-Pazi, Hilla; Butler, Erin; Chen, Robert; Collins, Abigail; Dayanidhi, Sudarshan; Forssberg, Hans; Fowler, Eileen; Gilbert, Donald L.; Gorman, Sharon L.; Gormley, Mark E.; Jinnah, H. A.; Kornblau, Barbara; Krosschell, Kristin; Lehman, Rebecca K.; MacKinnon, Colum; Malanga, C. J.; Mesterman, Ronit; Michaels, Margaret Barry; Pearson, Toni S.; Rose, Jessica; Russman, Barry; Sternad, Dagmar; Swoboda, Kathy; Valero-Cuevas, Francisco

    2010-01-01

    Hyperkinetic movements are unwanted or excess movements that are frequently seen in children with neurologic disorders. They are an important clinical finding with significant implications for diagnosis and treatment. However, the lack of agreement on standard terminology and definitions interferes with clinical treatment and research. We describe definitions of dystonia, chorea, athetosis, myoclonus, tremor, tics, and stereotypies that arose from a consensus meeting in June 2008 of specialists from different clinical and basic science fields. Dystonia is a movement disorder in which involuntary sustained or intermittent muscle contractions cause twisting and repetitive movements, abnormal postures, or both. Chorea is an ongoing random-appearing sequence of one or more discrete involuntary movements or movement fragments. Athetosis is a slow, continuous, involuntary writhing movement that prevents maintenance of a stable posture. Myoclonus is a sequence of repeated, often non-rhythmic, brief shock-like jerks due to sudden involuntary contraction or relaxation of one or more muscles. Tremor is a rhythmic back-and-forth or oscillating involuntary movement about a joint axis. Tics are repeated, individually recognizable, intermittent movements or movement fragments that are almost always briefly suppressible and are usually associated with awareness of an urge to perform the movement. Stereotypies are repetitive, simple movements that can be voluntarily suppressed. We provide recommended techniques for clinical examination and suggestions for differentiating between the different types of hyperkinetic movements, noting that there may be overlap between conditions. These definitions and the diagnostic recommendations are intended to be reliable and useful for clinical practice, communication between clinicians and researchers, and for the design of quantitative tests that will guide and assess the outcome of future clinical trials. PMID:20589866

  18. A new teaching model for demonstrating the movement of the extraocular muscles.

    PubMed

    Iwanaga, Joe; Refsland, Jason; Iovino, Lee; Holley, Gary; Laws, Tyler; Oskouian, Rod J; Tubbs, R Shane

    2017-09-01

    The extraocular muscles consist of the superior, inferior, lateral, and medial rectus muscles and the superior and inferior oblique muscles. This study aimed to create a new teaching model for demonstrating the function of the extraocular muscles. A coronal section of the head was prepared and sutures attached to the levator palpebral superioris muscle and six extraocular muscles. Tension was placed on each muscle from a posterior approach and movement of the eye documented from an anterior view. All movements were clearly seen less than that of the inferior rectus muscle. To our knowledge, this is the first cadaveric teaching model for demonstrating the movements of the extraocular muscles. Clin. Anat. 30:733-735, 2017. © 2017Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. Corticospinal Excitability in the Hand Muscles is Decreased During Eye Movement with Visual Occlusion.

    PubMed

    Chujo, Yuta; Jono, Yasutomo; Tani, Keisuke; Nomura, Yoshifumi; Hiraoka, Koichi

    2016-02-01

    Corticospinal excitability in the hand muscles decreases during smooth pursuit eye movement. The present study tested a hypothesis that the decrease in corticospinal excitability in the hand muscles at rest during eye movement is not caused by visual feedback but caused by motor commands to the eye muscles. Healthy men (M age = 28.4 yr., SD = 5.2) moved their eyes to the right with visual occlusion (dark goggles) while their arms and hands remained at rest. The motor-evoked potential in the hand muscles was suppressed by 19% in the third quarter of the eye-movement period, supporting a view that motor commands to the eye muscles are the cause of the decrease in corticospinal excitability in the hand muscles. The amount of the suppression was not significantly different among the muscles, indicating that modulation of corticospinal excitability in one muscle induced by eye movement is not dependent on whether eye movement direction and the direction of finger movement when the muscle contracts are identical. Thus, the finding failed to support a hypothetical view that motor commands to the eye muscles concomittantly produce motor commands to the hand muscles. Moreover, the amount of the suppression was not significantly different between the forearm positions, indicating that the suppression was not affected by proprioception of the forearm muscles when visual feedback is absent. © The Author(s) 2016.

  20. Mechanistic role of movement and strain sensitivity in muscle contraction

    PubMed Central

    Davis, Julien S.; Epstein, Neal D.

    2009-01-01

    Tension generation can be studied by applying step perturbations to contracting muscle fibers and subdividing the mechanical response into exponential phases. The de novo tension-generating isomerization is associated with one of these phases. Earlier work has shown that a temperature jump perturbs the equilibrium constant directly to increase tension. Here, we show that a length jump functions quite differently. A step release (relative movement of thick and thin filaments) appears to release a steric constraint on an ensemble of noncompetent postphosphate release actomyosin cross-bridges, enabling them to generate tension, a concentration jump in effect. Structural studies [Taylor KA, et al. (1999) Tomographic 3D reconstruction of quick-frozen, Ca2+-activated contracting insect flight muscle. Cell 99:421–431] that map to these kinetics indicate that both catalytic and lever arm domains of noncompetent myosin heads change angle on actin, whereas lever arm movement alone mediates the power stroke. Together, these kinetic and structural observations show a 13-nm overall interaction distance of myosin with actin, including a final 4- to 6-nm power stroke when the catalytic domain is fixed on actin. Raising fiber temperature with both perturbation techniques accelerates the forward, but slows the reverse rate constant of tension generation, kinetics akin to the unfolding/folding of small proteins. Decreasing strain, however, causes both forward and reverse rate constants to increase. Despite these changes in rate, the equilibrium constant is strain-insensitive. Activation enthalpy and entropy data show this invariance to be the result of enthalpy–entropy compensation. Reaction amplitudes confirm a strain-invariant equilibrium constant and thus a strain-insensitive ratio of pretension- to tension-generating states as work is done. PMID:19325123

  1. Counseling the Involuntary Client.

    ERIC Educational Resources Information Center

    Ritchie, Martin H.

    1986-01-01

    Involuntary clients resist efforts to help them because they do not admit having a problem, they do not want to change, or they do not know how to change. Specific techniques to help these clients overcome various kinds of reluctance and resistance are discussed. (Author/BL)

  2. Involuntary weight loss.

    PubMed

    Wong, Christopher J

    2014-05-01

    Involuntary weight loss remains an important and challenging clinical problem, with a high degree of morbidity and mortality. Because of the frequency of finding a serious underlying diagnosis, clinicians must be thorough in assessment, keeping in mind a broad range of possible causes. Although prediction scores exist, they have not been broadly validated; therefore, clinical judgment remains ever essential.

  3. Movement amplitude on the Functional Re-adaptive Exercise Device: deep spinal muscle activity and movement control.

    PubMed

    Winnard, A; Debuse, D; Wilkinson, M; Samson, L; Weber, T; Caplan, Nick

    2017-08-01

    Lumbar multifidus (LM) and transversus abdominis (TrA) show altered motor control, and LM is atrophied, in people with low-back pain (LBP). The Functional Re-adaptive Exercise Device (FRED) involves cyclical lower-limb movement against minimal resistance in an upright posture. It has been shown to recruit LM and TrA automatically, and may have potential as an intervention for non-specific LBP. However, no studies have yet investigated the effects of changes in FRED movement amplitude on the activity of these muscles. This study aimed to assess the effects of different FRED movement amplitudes on LM and TrA muscle thickness and movement variability, to inform an evidence-based exercise prescription. Lumbar multifidus and TrA thickness of eight healthy male volunteers were examined using ultrasound imaging during FRED exercise, normalised to rest at four different movement amplitudes. Movement variability was also measured. Magnitude-based inferences were used to compare each amplitude. Exercise at all amplitudes recruited LM and TrA more than rest, with thickness increases of approximately 5 and 1 mm, respectively. Larger amplitudes also caused increased TrA thickness, LM and TrA muscle thickness variability and movement variability. The data suggests that all amplitudes are useful for recruiting LM and TrA. A progressive training protocol should start in the smallest amplitude, increasing the setting once participants can maintain a consistent movement speed, to continue to challenge the motor control system.

  4. Management of involuntary childlessness.

    PubMed Central

    Himmel, W; Ittner, E; Kochen, M M; Michelmann, H W; Hinney, B; Reuter, M; Kallerhoff, M; Ringert, R H

    1997-01-01

    Any definition of involuntary childlessness has to consider the difference between sterility and subfertility. As the latter affects about 20-30% of all couples at least once in their lives, general practitioners (GPs) may be the first to be confronted with this problem. This review presents the most relevant diagnostic and therapeutic options in cases of female or male infertility, and discusses the new assisted reproductive technologies (such as insemination, in vitro fertilization, gamete transfer and intracytoplasmatic sperm injection) so that GPs may adequately inform their patients about these procedures and their risks and outcomes. Although controversial, involuntary childlessness and its clinical treatment seem to have a strong psychological impact on a couple's social, emotional and sexual life. Being available for discussion with childless couples and offering ongoing support may be the most important role for the GP in this context. PMID:9101672

  5. The Averaged EMGs Recorded from the Arm Muscles During Bimanual “Rowing” Movements

    PubMed Central

    Tomiak, Tomasz; Gorkovenko, Andriy V.; Tal'nov, Arkadii N.; Abramovych, Tetyana I.; Mishchenko, Viktor S.; Vereshchaka, Inna V.; Kostyukov, Alexander I.

    2015-01-01

    The main purpose was to analyze quantitatively the the average surface EMGs of the muscles that function around the elbow and shoulder joints of both arms in bimanual “rowing” movements, which were produced under identical elastic loads applied to the levers (“oars”). The muscles of PM group (“pulling” muscles: elbow flexors, shoulder extensors) generated noticeable velocity-dependent dynamic EMG components during the pulling and returning phases of movement and supported a steady-state activity during the hold phase. The muscles of RM group (“returning” muscles: elbow extensors, shoulder flexors) co-contracted with PM group during the movement phases and decreased activity during the hold phase. The dynamic components of the EMGs strongly depended on the velocity factor in both muscle groups, whereas the side and load factors and combinations of various factors acted only in PM group. Various subjects demonstrated diverse patterns of activity redistribution among muscles. We assume that central commands to the same muscles in two arms may be essentially different during execution of similar movement programs. Extent of the diversity in the EMG patterns of such muscles may reflect the subject's skilling in motor performance; on the other hand, the diversity can be connected with redistribution of activity between synergic muscles, thus providing a mechanism directed against development of the muscle fatigue. PMID:26640440

  6. Skeletal muscle tissue in movement and health: positives and negatives.

    PubMed

    Lindstedt, Stan L

    2016-01-01

    The history of muscle physiology is a wonderful lesson in 'the scientific method'; our functional hypotheses have been limited by our ability to decipher (observe) muscle structure. The simplistic understanding of how muscles work made a large leap with the remarkable insights of A. V. Hill, who related muscle force and power to shortening velocity and energy use. However, Hill's perspective was largely limited to isometric and isotonic contractions founded on isolated muscle properties that do not always reflect how muscles function in vivo. Robert Josephson incorporated lengthening contractions into a work loop analysis that shifted the focus to dynamic muscle function, varying force, length and work done both by and on muscle during a single muscle work cycle. It became apparent that muscle is both a force generator and a spring. Titin, the missing filament in the sliding filament model, is a muscle spring, which functions very differently in cardiac versus skeletal muscle; its possible role in these two muscle types is discussed relative to their contrasting function. The good news for those of us who choose to work on skeletal muscle is that muscle has been reluctant to reveal all of its secrets. © 2016. Published by The Company of Biologists Ltd.

  7. Contributions of skin and muscle afferent input to movement sense in the human hand.

    PubMed

    Cordo, Paul J; Horn, Jean-Louis; Künster, Daniela; Cherry, Anne; Bratt, Alex; Gurfinkel, Victor

    2011-04-01

    In the stationary hand, static joint-position sense originates from multimodal somatosensory input (e.g., joint, skin, and muscle). In the moving hand, however, it is uncertain how movement sense arises from these different submodalities of proprioceptors. In contrast to static-position sense, movement sense includes multiple parameters such as motion detection, direction, joint angle, and velocity. Because movement sense is both multimodal and multiparametric, it is not known how different movement parameters are represented by different afferent submodalities. In theory, each submodality could redundantly represent all movement parameters, or, alternatively, different afferent submodalities could be tuned to distinctly different movement parameters. The study described in this paper investigated how skin input and muscle input each contributes to movement sense of the hand, in particular, to the movement parameters dynamic position and velocity. Healthy adult subjects were instructed to indicate with the left hand when they sensed the unseen fingers of the right hand being passively flexed at the metacarpophalangeal (MCP) joint through a previously learned target angle. The experimental approach was to suppress input from skin and/or muscle: skin input by anesthetizing the hand, and muscle input by unexpectedly extending the wrist to prevent MCP flexion from stretching the finger extensor muscle. Input from joint afferents was assumed not to play a significant role because the task was carried out with the MCP joints near their neutral positions. We found that, during passive finger movement near the neutral position in healthy adult humans, both skin and muscle receptors contribute to movement sense but qualitatively differently. Whereas skin input contributes to both dynamic position and velocity sense, muscle input may contribute only to velocity sense.

  8. Physiological tremor reveals how thixotropy adapts skeletal muscle for posture and movement.

    PubMed

    Vernooij, Carlijn A; Reynolds, Raymond F; Lakie, Martin

    2016-05-01

    People and animals can move freely, but they must also be able to stay still. How do skeletal muscles economically produce both movement and posture? Humans are well known to have motor units with relatively homogeneous mechanical properties. Thixotropic muscle properties can provide a solution by providing a temporary stiffening of all skeletal muscles in postural conditions. This stiffening is alleviated almost instantly when muscles start to move. In this paper, we probe this behaviour. We monitor both the neural input to a muscle, measured here as extensor muscle electromyography (EMG), and its output, measured as tremor (finger acceleration). Both signals were analysed continuously as the subject made smooth transitions between posture and movement. The results showed that there were marked changes in tremor which systematically increased in size and decreased in frequency as the subject moved faster. By contrast, the EMG changed little and reflected muscle force requirement rather than movement speed. The altered tremor reflects naturally occurring thixotropic changes in muscle behaviour. Our results suggest that physiological tremor provides useful and hitherto unrecognized insights into skeletal muscle's role in posture and movement.

  9. Physiological tremor reveals how thixotropy adapts skeletal muscle for posture and movement

    PubMed Central

    Vernooij, Carlijn A.; Reynolds, Raymond F.; Lakie, Martin

    2016-01-01

    People and animals can move freely, but they must also be able to stay still. How do skeletal muscles economically produce both movement and posture? Humans are well known to have motor units with relatively homogeneous mechanical properties. Thixotropic muscle properties can provide a solution by providing a temporary stiffening of all skeletal muscles in postural conditions. This stiffening is alleviated almost instantly when muscles start to move. In this paper, we probe this behaviour. We monitor both the neural input to a muscle, measured here as extensor muscle electromyography (EMG), and its output, measured as tremor (finger acceleration). Both signals were analysed continuously as the subject made smooth transitions between posture and movement. The results showed that there were marked changes in tremor which systematically increased in size and decreased in frequency as the subject moved faster. By contrast, the EMG changed little and reflected muscle force requirement rather than movement speed. The altered tremor reflects naturally occurring thixotropic changes in muscle behaviour. Our results suggest that physiological tremor provides useful and hitherto unrecognized insights into skeletal muscle's role in posture and movement. PMID:27293785

  10. Change in length of relaxed muscle fascicles and tendons with knee and ankle movement in humans

    PubMed Central

    Herbert, R D; Moseley, A M; Butler, J E; Gandevia, S C

    2002-01-01

    Ultrasonography was used to measure changes in length of muscle fascicles in relaxed human tibialis anterior and gastrocnemius during passively imposed changes in joint angle. Changes in the length of muscle fascicles were compared to changes in the length of the whole muscle-tendon units calculated from joint angles and anthropometric data. Relaxed muscle fascicles underwent much smaller changes in length than their muscle-tendon units. On average, muscle fascicles in tibialis anterior [saw] 55 ± 13 % (mean ± s.d.) of the total change in muscle-tendon length. This indicates nearly half of the total change in muscle-tendon length was taken up by stretch of tendon. In gastrocnemius, which has relatively long tendons, only 27 ± 9 % of the total change in muscle-tendon length was transmitted to muscle fascicles. Thus, the tendency for passive movement to be taken up by the tendon was greater for gastrocnemius than tibialis anterior (P = 0.002). For these muscles, the relatively large changes in tendon length across much of the physiological range of muscle-tendon lengths could not wholly be explained by tendon slackness, changes in fibre pennation, or stretch or contraction history of the muscle. Our data confirm that when joints are moved passively, length changes [seen] by muscle fascicles can be much less than changes in the distance between muscle origin and insertion. This occurs because tendons undergo significant changes in length, even at very low forces. PMID:11882694

  11. Simulating the activation, contraction and movement of skeletal muscles using the bidomain model.

    PubMed

    Lopez Rincon, A; Cantu, C; Soto, R; Shimoda, S

    2016-08-01

    A simulation of the muscle activation, contraction and movement is here presented. This system was developed based on the Bidomain mathematical model of the electrical propagation in muscles. This study shows an electrical stimuli input to a muscle and how this behave. The comparison between healthy subject and patient with muscle activation impairment is depicted, depending on whether the signal reaches a threshold. A 3D model of a bicep muscle and a forearm bone connected was constructed using OpenGL. This platform could be used for development of controllers for biomechatronic systems in future works. This kind of bioinspired model could be used for a better understanding of the neuromotor system.

  12. Abnormal Cortex-Muscle Interactions in Subjects with X-linked Kallmann's Syndrome and Mirror Movements

    ERIC Educational Resources Information Center

    Farmer, S. F.; Harrison, L. M.; Mayston, M. J.; Parekh, A.; James, L. M.; Stephens, J. A.

    2004-01-01

    X-linked Kallmann's (XKS) subjects, who display mirror movements, have abnormal corticospinal tracts which innervate motoneurons of the left and right distal muscles of the upper limb. The size of the abnormal ipsilateral projection is variable. We have used coherence and cumulant analysis between EEG and first dorsal interosseous muscle (1DI) EMG…

  13. Abnormal Cortex-Muscle Interactions in Subjects with X-linked Kallmann's Syndrome and Mirror Movements

    ERIC Educational Resources Information Center

    Farmer, S. F.; Harrison, L. M.; Mayston, M. J.; Parekh, A.; James, L. M.; Stephens, J. A.

    2004-01-01

    X-linked Kallmann's (XKS) subjects, who display mirror movements, have abnormal corticospinal tracts which innervate motoneurons of the left and right distal muscles of the upper limb. The size of the abnormal ipsilateral projection is variable. We have used coherence and cumulant analysis between EEG and first dorsal interosseous muscle (1DI) EMG…

  14. Association of Orofacial Muscle Activity and Movement during Changes in Speech Rate and Intensity

    ERIC Educational Resources Information Center

    McClean, Michael D.; Tasko, Stephen M.

    2003-01-01

    Understanding how orofacial muscle activity and movement covary across changes in speech rate and intensity has implications for the neural control of speech production and the use of clinical procedures that manipulate speech prosody. The present study involved a correlation analysis relating average lower-lip and jaw-muscle activity to lip and…

  15. Association of Orofacial Muscle Activity and Movement during Changes in Speech Rate and Intensity

    ERIC Educational Resources Information Center

    McClean, Michael D.; Tasko, Stephen M.

    2003-01-01

    Understanding how orofacial muscle activity and movement covary across changes in speech rate and intensity has implications for the neural control of speech production and the use of clinical procedures that manipulate speech prosody. The present study involved a correlation analysis relating average lower-lip and jaw-muscle activity to lip and…

  16. Muscle activity during mandibular movements in normal and mandibular retrognathic subjects.

    PubMed

    Harper, R P; de Bruin, H; Burcea, I

    1997-03-01

    The masticatory muscles function as a unit during precise mandibular positioning movements that occur during such activities as speech, singing, or playing musical instruments. This investigation was designed to assess jaw muscle recruitment patterns during controlled mandibular movement in normal subjects and in patients with mandibular retrognathism. A computer-integrated electromyography (EMG) and movement monitoring (Selspot) system was used to collect data over 7 seconds of a sagittal border movement (Posselt envelope) of the mandible and 4 seconds each of rest position, light tooth contact, and maximum clench. Fine wire bipolar electrodes were placed into the inferior belly of the lateral pterygoid muscles bilaterally and surface electrodes were placed bilaterally over the anterior belly of the temporalis muscles and the masseter muscles. Ten subjects with Class I occlusion, normal cephalometric values, and an absence of temporomandibular joint (TMJ) dysfunction were compared with 12 patients with mandibular retrognathism, Class II malocclusion, and an absence of clinical signs of TMJ internal derangement before and after a bilateral sagittal split and advancement of the mandible. There was a wide variation in standard deviations of EMG activity for the lateral pterygoid muscles in the retrognathic patients compared with normal controls before surgery (P < .05). In light tooth contact, temporalis muscle activity increased after surgery with respect to both control and the presurgical levels (P < .05, P < .005, respectively). In maximum clench, activity in all muscle groups in the retrognathic patients, both before and after surgery, were below that of control subjects (P < .005). The lateral pterygoid muscles showed late recruitment, with low EMG activity levels during the forward movement phase of the envelope, before surgery compared with controls (P < .001). After surgery, the lateral pterygoid muscle showed early recruitment in the forward movement

  17. Muscle-spring dynamics in time-limited, elastic movements.

    PubMed

    Rosario, M V; Sutton, G P; Patek, S N; Sawicki, G S

    2016-09-14

    Muscle contractions that load in-series springs with slow speed over a long duration do maximal work and store the most elastic energy. However, time constraints, such as those experienced during escape and predation behaviours, may prevent animals from achieving maximal force capacity from their muscles during spring-loading. Here, we ask whether animals that have limited time for elastic energy storage operate with springs that are tuned to submaximal force production. To answer this question, we used a dynamic model of a muscle-spring system undergoing a fixed-end contraction, with parameters from a time-limited spring-loader (bullfrog: Lithobates catesbeiana) and a non-time-limited spring-loader (grasshopper: Schistocerca gregaria). We found that when muscles have less time to contract, stored elastic energy is maximized with lower spring stiffness (quantified as spring constant). The spring stiffness measured in bullfrog tendons permitted less elastic energy storage than was predicted by a modelled, maximal muscle contraction. However, when muscle contractions were modelled using biologically relevant loading times for bullfrog jumps (50 ms), tendon stiffness actually maximized elastic energy storage. In contrast, grasshoppers, which are not time limited, exhibited spring stiffness that maximized elastic energy storage when modelled with a maximal muscle contraction. These findings demonstrate the significance of evolutionary variation in tendon and apodeme properties to realistic jumping contexts as well as the importance of considering the effect of muscle dynamics and behavioural constraints on energy storage in muscle-spring systems. © 2016 The Author(s).

  18. Inducing any virtual two-dimensional movement in humans by applying muscle tendon vibration.

    PubMed

    Roll, Jean-Pierre; Albert, Frédéric; Thyrion, Chloé; Ribot-Ciscar, Edith; Bergenheim, Mikael; Mattei, Benjamin

    2009-02-01

    In humans, tendon vibration evokes illusory sensation of movement. We developed a model mimicking the muscle afferent patterns corresponding to any two-dimensional movement and checked its validity by inducing writing illusory movements through specific sets of muscle vibrators. Three kinds of illusory movements were compared. The first was induced by vibration patterns copying the responses of muscle spindle afferents previously recorded by microneurography during imposed ankle movements. The two others were generated by the model. Sixteen different vibratory patterns were applied to 20 motionless volunteers in the absence of vision. After each vibration sequence, the participants were asked to name the corresponding graphic symbol and then to reproduce the illusory movement perceived. Results showed that the afferent patterns generated by the model were very similar to those recorded microneurographically during actual ankle movements (r=0.82). The model was also very efficient for generating afferent response patterns at the wrist level, if the preferred sensory directions of the wrist muscle groups were first specified. Using recorded and modeled proprioceptive patterns to pilot sets of vibrators placed at the ankle or wrist levels evoked similar illusory movements, which were correctly identified by the participants in three quarters of the trials. Our proprioceptive model, based on neurosensory data recorded in behaving humans, should then be a useful tool in fields of research such as sensorimotor learning, rehabilitation, and virtual reality.

  19. Trunk Muscle Activation at the Initiation and Braking of Bilateral Shoulder Flexion Movements of Different Amplitudes

    PubMed Central

    Eriksson Crommert, M.; Halvorsen, K.; Ekblom, M. M.

    2015-01-01

    The aim of this study was to investigate if trunk muscle activation patterns during rapid bilateral shoulder flexions are affected by movement amplitude. Eleven healthy males performed shoulder flexion movements starting from a position with arms along sides (0°) to either 45°, 90° or 180°. EMG was measured bilaterally from transversus abdominis (TrA), obliquus internus (OI) with intra-muscular electrodes, and from rectus abdominis (RA), erector spinae (ES) and deltoideus with surface electrodes. 3D kinematics was recorded and inverse dynamics was used to calculate the reactive linear forces and torque about the shoulders and the linear and angular impulses. The sequencing of trunk muscle onsets at the initiation of arm movements was the same across movement amplitudes with ES as the first muscle activated, followed by TrA, RA and OI. All arm movements induced a flexion angular impulse about the shoulders during acceleration that was reversed during deceleration. Increased movement amplitude led to shortened onset latencies of the abdominal muscles and increased level of activation in TrA and ES. The activation magnitude of TrA was similar in acceleration and deceleration where the other muscles were specific to acceleration or deceleration. The findings show that arm movements need to be standardized when used as a method to evaluate trunk muscle activation patterns and that inclusion of the deceleration of the arms in the analysis allow the study of the relationship between trunk muscle activation and direction of perturbing torque during one and the same arm movement. PMID:26562017

  20. Trunk Muscle Activation at the Initiation and Braking of Bilateral Shoulder Flexion Movements of Different Amplitudes.

    PubMed

    Eriksson Crommert, M; Halvorsen, K; Ekblom, M M

    2015-01-01

    The aim of this study was to investigate if trunk muscle activation patterns during rapid bilateral shoulder flexions are affected by movement amplitude. Eleven healthy males performed shoulder flexion movements starting from a position with arms along sides (0°) to either 45°, 90° or 180°. EMG was measured bilaterally from transversus abdominis (TrA), obliquus internus (OI) with intra-muscular electrodes, and from rectus abdominis (RA), erector spinae (ES) and deltoideus with surface electrodes. 3D kinematics was recorded and inverse dynamics was used to calculate the reactive linear forces and torque about the shoulders and the linear and angular impulses. The sequencing of trunk muscle onsets at the initiation of arm movements was the same across movement amplitudes with ES as the first muscle activated, followed by TrA, RA and OI. All arm movements induced a flexion angular impulse about the shoulders during acceleration that was reversed during deceleration. Increased movement amplitude led to shortened onset latencies of the abdominal muscles and increased level of activation in TrA and ES. The activation magnitude of TrA was similar in acceleration and deceleration where the other muscles were specific to acceleration or deceleration. The findings show that arm movements need to be standardized when used as a method to evaluate trunk muscle activation patterns and that inclusion of the deceleration of the arms in the analysis allow the study of the relationship between trunk muscle activation and direction of perturbing torque during one and the same arm movement.

  1. 28 CFR 549.42 - Involuntary admission.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SERVICES Administrative Safeguards for Psychiatric Treatment and Medication § 549.42 Involuntary admission... voluntarily consent either to psychiatric admission or to medication, is subject to judicial involuntary...

  2. Neural representation of muscle dynamics in voluntary movement control.

    PubMed

    Hasson, Christopher J

    2014-07-01

    Several theories of motor control posit that the nervous system has access to a neural representation of muscle dynamics. Yet, this has not been tested experimentally. Should such a representation exist, it was hypothesized that subjects who learned to control a virtual limb using virtual muscles would improve performance faster and show greater generalization than those who learned with a less dynamically complex virtual force generator. Healthy adults practiced using their biceps brachii activity to move a myoelectrically controlled virtual limb from rest to a standard target position with maximum speed and accuracy. Throughout practice, generalization was assessed with untrained target trials and sensitivity to actuator dynamics was probed by unexpected actuator model switches. In a muscle model subject group (n = 10), the biceps electromyographic signal activated a virtual muscle that pulled on the virtual limb with a force governed by muscle dynamics, defined by a nonlinear force-length-velocity relation and series elastic stiffness. A force generator group (n = 10) performed the same task, but the actuation force was a linear function of the biceps activation signal. Both groups made significant errors with unexpected actuator dynamics switches, supporting task sensitivity to actuator dynamics. The muscle model group improved performance as fast as the force generator group and showed greater generalization in early practice, despite using an actuator with more complex dynamics. These results are consistent with a preexisting neural representation of muscle dynamics, which may have offset any learning challenges associated with the more dynamically complex virtual muscle model.

  3. An action potential-driven model of soleus muscle activation dynamics for locomotor-like movements

    PubMed Central

    Kim, Hojeong; Sandercock, Thomas G.; Heckman, C. J.

    2016-01-01

    Objective The goal of this study was to develop a physiologically plausible, computationally robust model for the muscle activation dynamics (A(t)) under physiologically relevant excitation and movement. Approach The interaction of excitation and movement on A(t) was investigated comparing the force production between a cat soleus muscle and its Hill-type model. For capturing A(t) under excitation and movement variation, a modular modeling framework was proposed comprising of 3 compartments: (1) spikes-to-[Ca2+]; (2) [Ca2+]-to-A; and (3) A-to-force transformation. The individual signal transformations were modeled based on physiological factors so that the parameter values could be separately determined for individual modules directly based on experimental data. Main results The strong dependency of A(t) on excitation frequency and muscle length was found during both isometric and dynamically-moving contractions. The identified dependencies of A(t) under the static and dynamic conditions could be incorporated in the modular modeling framework by modulating the model parameters as a function of movement input. The new modeling approach was also applicable to cat soleus muscles producing waveforms independent of those used to set the model parameters. Significance This study provides a modeling framework for spike-driven muscle responses during movement, that is suitable not only for insights into molecular mechanisms underlying muscle behaviors but also for large scale simulations. PMID:26087477

  4. An action potential-driven model of soleus muscle activation dynamics for locomotor-like movements

    NASA Astrophysics Data System (ADS)

    Kim, Hojeong; Sandercock, Thomas G.; Heckman, C. J.

    2015-08-01

    Objective. The goal of this study was to develop a physiologically plausible, computationally robust model for muscle activation dynamics (A(t)) under physiologically relevant excitation and movement. Approach. The interaction of excitation and movement on A(t) was investigated comparing the force production between a cat soleus muscle and its Hill-type model. For capturing A(t) under excitation and movement variation, a modular modeling framework was proposed comprising of three compartments: (1) spikes-to-[Ca2+]; (2) [Ca2+]-to-A; and (3) A-to-force transformation. The individual signal transformations were modeled based on physiological factors so that the parameter values could be separately determined for individual modules directly based on experimental data. Main results. The strong dependency of A(t) on excitation frequency and muscle length was found during both isometric and dynamically-moving contractions. The identified dependencies of A(t) under the static and dynamic conditions could be incorporated in the modular modeling framework by modulating the model parameters as a function of movement input. The new modeling approach was also applicable to cat soleus muscles producing waveforms independent of those used to set the model parameters. Significance. This study provides a modeling framework for spike-driven muscle responses during movement, that is suitable not only for insights into molecular mechanisms underlying muscle behaviors but also for large scale simulations.

  5. Anticipatory postural adjustments to arm movement reveal complex control of paraspinal muscles in the thorax.

    PubMed

    Lee, Linda-Joy; Coppieters, Michel W; Hodges, Paul W

    2009-02-01

    Anatomical and empirical data suggest that deep and superficial muscles may have different functions for thoracic spine control. This study investigated thoracic paraspinal muscle activity during anticipatory postural adjustments associated with arm movement. Electromyographic (EMG) recordings were made from the right deep (multifidus/rotatores) and superficial (longissimus) muscles at T5, T8, and T11 levels using fine-wire electrodes. Ten healthy participants performed fast unilateral and bilateral flexion and extension arm movements in response to a light. EMG amplitude was measured during 25ms epochs for 150ms before and 400ms after deltoid EMG onset. During arm flexion movements, multifidus and longissimus had two bursts of activity, one burst prior to deltoid and a late burst. With arm extension both muscles were active in a single burst after deltoid onset. There was differential activity with respect to direction of trunk rotation induced by arm movement. Right longissimus was most active with left arm movements and right multifidus was most active with right arm movements. All levels of the thorax responded similarly. We suggest that although thoracic multifidus and longissimus function similarly to control sagittal plane perturbations, these muscles are differentially active with rotational forces on the trunk.

  6. The combination of lithium and L-Dopa/Carbidopa reduces MPTP-induced abnormal involuntary movements (AIMs) via calpain-1 inhibition in a mouse model: relevance for Parkinson's disease therapy

    PubMed Central

    Lazzara, Carol A.; Riley, Rebeccah R.; Rane, Anand; Andersen, Julie K.; Kim, Yong-Hwan

    2015-01-01

    Lithium has recently been suggested to have neuroprotective effects in several models of neurodegenerative disease including Parkinson’s disease (PD). Levodopa (L-Dopa) replacement therapy remains the most common and effective treatment for PD, although it induces the complication of L-Dopa induced dyskinesia after years of use. Here we examined the potential use of lithium in combination with L-Dopa/Carbidopa for both reducing MPTP-induced abnormal involuntary movements (AIMs) as well as protecting against cell death in MPTP-lesioned mice. Chronic lithium administration (0.127% LiCl in the feed) in the presence of daily L-Dopa/Carbidopa injection for a period of 2 months was sufficient to effectively reduce MPTP-induced AIMs in mice. Mechanistically, lithium was found to suppress MPTP-induced calpain activities in vivo coinciding with down-regulation of calpain-1 but not calpain-2 expression in both the striatum (ST) and the brain stem (BS). Calpain inhibition has previously been associated with increased levels of the rate-limiting enzyme in dopamine synthesis, tyrosine hydroxylase (TH), which is probably mediated by the up-regulation of the transcription factors MEF-2A and 2D. Lithium was found to induce up-regulation of TH expression in the ST and the BS, as well as in N27 rat dopaminergic cells. Further, histone acetyltransferase (HAT) expression was substantially up-regulated by lithium treatment in vitro. These results suggest the potential use of lithium in combination with L-Dopa/Carbidopa not only as a neuroprotectant, but also for reducing AIMs and possibly alleviating potential side-effects associated with the current treatment for PD. PMID:26119916

  7. Pairing Voluntary Movement and Muscle-Located Electrical Stimulation Increases Cortical Excitability

    PubMed Central

    Jochumsen, Mads; Niazi, Imran K.; Signal, Nada; Nedergaard, Rasmus W.; Holt, Kelly; Haavik, Heidi; Taylor, Denise

    2016-01-01

    Learning new motor skills has been correlated with increased cortical excitability. In this study, different location of electrical stimulation (ES), nerve, or muscle, was paired with voluntary movement to investigate if ES paired with voluntary movement (a) would increase the excitability of cortical projections to tibialis anterior and (b) if stimulation location mattered. Cortical excitability changes were quantified using motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) at varying intensities during four conditions. Twelve healthy subjects performed 50 dorsiflexions at the ankle during nerve or muscle ES at motor threshold (MTh). ES alone was delivered 50 times and the movement was performed 50 times. A significant increase in the excitability from pre- to post-intervention (P = 0.0061) and pre- to 30 min post-intervention (P = 0.017) measurements was observed when voluntary movement was paired with muscle ES located at tibialis anterior. An increase of 50 ± 57 and 28 ± 54% in the maximum MEPs was obtained for voluntary movement paired with muscle-located and nerve-located ES, respectively. The maximum MEPs for voluntary movement alone and muscle-located ES alone were −5 ± 28 and 2 ± 42%, respectively. Pairing voluntary movement with muscle-located ES increases excitability of corticospinal projections of tibialis anterior in healthy participants. This finding suggests that active participation during muscle-located ES protocols increases cortical excitability to a greater extent than stimulation alone. The next stage of this research is to investigate the effect in people with stroke. The results may have implications for motor recovery in patients with motor impairments following neurological injury. PMID:27733823

  8. Realization of masticatory movement by 3-dimensional simulation of the temporomandibular joint and the masticatory muscles.

    PubMed

    Park, Jong-Tae; Lee, Jae-Gi; Won, Sung-Yoon; Lee, Sang-Hee; Cha, Jung-Yul; Kim, Hee-Jin

    2013-07-01

    Masticatory muscles are closely involved in mastication, pronunciation, and swallowing, and it is therefore important to study the specific functions and dynamics of the mandibular and masticatory muscles. However, the shortness of muscle fibers and the diversity of movement directions make it difficult to study and simplify the dynamics of mastication. The purpose of this study was to use 3-dimensional (3D) simulation to observe the functions and movements of each of the masticatory muscles and the mandible while chewing. To simulate the masticatory movement, computed tomographic images were taken from a single Korean volunteer (30-year-old man), and skull image data were reconstructed in 3D (Mimics; Materialise, Leuven, Belgium). The 3D-reconstructed masticatory muscles were then attached to the 3D skull model. The masticatory movements were animated using Maya (Autodesk, San Rafael, CA) based on the mandibular motion path. During unilateral chewing, the mandible was found to move laterally toward the functional side by contracting the contralateral lateral pterygoid and ipsilateral temporalis muscles. During the initial mouth opening, only hinge movement was observed at the temporomandibular joint. During this period, the entire mandible rotated approximately 13 degrees toward the bicondylar horizontal plane. Continued movement of the mandible to full mouth opening occurred simultaneously with sliding and hinge movements, and the mandible rotated approximately 17 degrees toward the center of the mandibular ramus. The described approach can yield data for use in face animation and other simulation systems and for elucidating the functional components related to contraction and relaxation of muscles during mastication.

  9. Contribution of elastic tissues to the mechanics and energetics of muscle function during movement.

    PubMed

    Roberts, Thomas J

    2016-01-01

    Muscle force production occurs within an environment of tissues that exhibit spring-like behavior, and this elasticity is a critical determinant of muscle performance during locomotion. Muscle force and power output both depend on the speed of contraction, as described by the isotonic force-velocity curve. By influencing the speed of contractile elements, elastic structures can have a profound effect on muscle force, power and work. In very rapid movements, elastic mechanisms can amplify muscle power by storing the work of muscle contraction slowly and releasing it rapidly. When energy must be dissipated rapidly, such as in landing from a jump, energy stored rapidly in elastic elements can be released more slowly to stretch muscle contractile elements, reducing the power input to muscle and possibly protecting it from damage. Elastic mechanisms identified so far rely primarily on in-series tendons, but many structures within muscles exhibit spring-like properties. Actomyosin cross-bridges, actin and myosin filaments, titin, and the connective tissue scaffolding of the extracellular matrix all have the potential to store and recover elastic energy during muscle contraction. The potential contribution of these elements can be assessed from their stiffness and estimates of the strain they undergo during muscle function. Such calculations provide boundaries for the possible roles these springs might play in locomotion, and may help to direct future studies of the uses of elastic elements in muscle. © 2016. Published by The Company of Biologists Ltd.

  10. Muscle activation patterns in acceleration-based phases during reach-to-grasp movement

    PubMed Central

    Tokuda, Keisuke; Lee, Bumsuk; Shiihara, Yasufumi; Takahashi, Kazuhiro; Wada, Naoki; Shirakura, Kenji; Watanabe, Hideomi

    2016-01-01

    [Purpose] An earlier study divided reaching activity into characteristic phases based on hand velocity profiles. By synchronizing muscle activities and the acceleration profile, a phasing approach for reaching movement, based on hand acceleration profiles, was attempted in order to elucidate the roles of individual muscle activities in the different phases of the acceleration profile in reaching movements. [Subjects and Methods] Ten healthy volunteer subjects participated in this study. The aim was to electromyographically evaluate muscles around the shoulder, the upper trapezius, the anterior deltoid, the biceps brachii, and the triceps brachii, most of which have been used to evaluate arm motion, as well as the acceleration of the upper limb during simple reaching movement in the reach-to-grasp task. [Results] Analysis showed the kinematic trajectories of the acceleration during a simple biphasic profile of the reaching movement could be divided into four phases: increasing acceleration (IA), decreasing acceleration (DA), increasing deceleration (ID), and decreasing deceleration (DD). Muscles around the shoulder showed different activity patterns, which were closely associated with these acceleration phases. [Conclusion] These results suggest the important role of the four phases, derived from the acceleration trajectory, in the elucidation of the muscular mechanisms which regulate and coordinate the muscles around the shoulder in reaching movements. PMID:27942129

  11. Review and Perspective: Neuromechanical considerations for predicting muscle activation patterns for movement

    PubMed Central

    Ting, Lena H.; Chvatal, Stacie A.; Safavynia, Seyed A.; McKay, J. Lucas

    2014-01-01

    Muscle coordination may be difficult or impossible to predict accurately based on biomechanical considerations alone due to redundancy in the musculoskeletal system. Because many solutions exist for any given movement, the role of the nervous system in further constraining muscle coordination patterns for movement must be considered in both healthy and impaired motor control. Based on computational neuromechanical analyses of experimental data combined with modeling techniques, we have demonstrated several such neural constraints on the temporal and spatial patterns of muscle activity during both locomotion and postural responses to balance perturbations. We hypothesize that subject-specific as well as trial-by-trial differences in muscle activation can be parameterized and understood by a hierarchical and low-dimensional framework that reflects the neural control of task-level goals. In postural control, we demonstrate that temporal patterns of muscle activity may be governed by feedback control of task-level variables that represent the overall goal-directed motion of the body. These temporal patterns then recruit spatially-fixed patterns of muscle activity called muscle synergies that produce the desired task-level biomechanical functions that require multi-joint coordination. Moreover, these principles apply more generally to movement, and in particular to locomotor tasks in both healthy and impaired individuals. Overall, understanding the goals and organization of the neural control of movement may provide useful reduced dimension parameter sets to address the degrees-of-freedom problem in musculoskeletal movement control. More importantly, however, neuromechanical analyses may lend insight and provide a framework for understanding subject-specific and trial-by-trial differences in movement across both healthy and motor-impaired populations. PMID:23027631

  12. An Assessment of Six Muscle Spindle Models for Predicting Sensory Information during Human Wrist Movements

    PubMed Central

    Malik, Puja; Jabakhanji, Nuha; Jones, Kelvin E.

    2016-01-01

    Background: The muscle spindle is an important sensory organ for proprioceptive information, yet there have been few attempts to use Shannon information theory to quantify the capacity of human muscle spindles to encode sensory input. Methods: Computer simulations linked kinematics, to biomechanics, to six muscle spindle models that generated predictions of firing rate. The predicted firing rates were compared to firing rates of human muscle spindles recorded during a step-tracking (center-out) task to validate their use. The models were then used to predict firing rates during random movements with statistical properties matched to the ergonomics of human wrist movements. The data were analyzed for entropy and mutual information. Results: Three of the six models produced predictions that approximated the firing rate of human spindles during the step-tracking task. For simulated random movements these models predicted mean rates of 16.0 ± 4.1 imp/s (mean ± SD), peak firing rates <50 imp/s and zero firing rate during an average of 25% of the movement. The average entropy of the neural response was 4.1 ± 0.3 bits and is an estimate of the maximum information that could be carried by muscles spindles during ecologically valid movements. The information about tendon displacement preserved in the neural response was 0.10 ± 0.05 bits per symbol; whereas 1.25 ± 0.30 bits per symbol of velocity input were preserved in the neural response of the spindle models. Conclusions: Muscle spindle models, originally based on cat experiments, have predictive value for modeling responses of human muscle spindles with minimal parameter optimization. These models predict more than 10-fold more velocity over length information encoding during ecologically valid movements. These results establish theoretical parameters for developing neuroprostheses for proprioceptive function. PMID:26834618

  13. Jaw movement alters the reaction of human jaw muscles to incisor stimulation.

    PubMed

    Brinkworth, Russell S A; Türker, Kemal S

    2005-07-01

    The changes in the minimum time to consciously react (reaction time) and the order of jaw muscle recruitment to precisely controlled axial stimulation of the incisors during controlled jaw movements are not known. To this end, ten subjects were recruited to investigate the reaction time of bilateral temporalis and masseter muscles and bite force. Stimuli were delivered axially to the upper central incisors during active jaw closing and opening, and under static conditions. The results showed that the reaction time was increased an average of 35% during both jaw opening and closing movements when compared with static jaw conditions. The left temporalis was recruited approximately 10 ms before the right temporalis, whereas no significant side differences were found between the masseter muscles. The masseter muscles were recruited an average of 20 ms before the temporalis muscles during jaw closing, but no difference existed during opening. Under static conditions the reaction time in the bite force was approximately 16 ms longer than the left temporalis, but was not significantly different from the reaction time of any of the other muscles, indicating that, under the static conditions tested, the left temporalis was more often responsible for initiation of the mechanical reactions in the jaw. Because of active compensation, no force measurements were made during jaw movement. This study is a prerequisite for investigations into the modulation of reflexes during jaw movement, because a response to a stimulus commencing after the minimum reaction time may not be entirely reflex in origin.

  14. Muscle coordination in complex movements during Jeté in skilled ballet dancers.

    PubMed

    Lepelley, Marie-Charlotte; Thullier, Francine; Koral, Jérôme; Lestienne, Francis G

    2006-11-01

    The principal goal of our study is to gain an insight into the coordinative structure of a complex body movement. As a first step, this paper describes the activity of multiple skeletal muscles associated with the drawing-like movements that resemble the Jeté, performed by skilled ballet dancers. The EMG activity of 18 muscles of the trunk, pelvis, and both legs was recorded when dancers standing on the left leg moved the toe of the right leg forward and backward along a straight line. A major finding is that the EMG activity of all right muscles, despite their functional and anatomical diversity, was minimised not only at the initial, vertical position but also in the reversal phase of movement when the moving leg was maximally deviated from the vertical position. In other words, the activity was minimal when torques of the weights of limb segments were minimal as well as when these torques were maximal. In contrast, in the static task when the maximally deviated leg position was maintained, there was substantial tonic activation of leg muscles, an activity that was necessary to balance these torques. The result is consistent with the hypothesis that movements of the body result from centrally induced changes in the muscle recruitment thresholds influencing the referent configuration of the body. The existence of minima in the overall EMG activity of skeletal muscles is not the only prediction of the referent configuration hypothesis. An immediate consequence of the hypothesis is that, in movements of the limb, the EMG patterns should be a direction-dependent phenomenon known as "directional tuning" of muscles. In combination with the principle of minimal interaction of neuromuscular system, the referent configuration hypothesis offers a dynamic approach to the problems of how control levels may guide multi-muscle and multi-joint systems without redundancy problems.

  15. Out-of-plane trunk movements and trunk muscle activity after a trip during walking.

    PubMed

    van der Burg, J C E; Pijnappels, M; van Dieën, J H

    2005-09-01

    Tripping during gait occurs frequently. A successful balance recovery implies that the forward body rotation is sufficiently reduced. In view of this, adequate control of the trunk momentum is important, as the trunk has a high inertia. The aim of this study was to establish out-of-plane trunk movements after a trip and to determine trunk muscle responses. Ten male volunteers repeatedly walked over a platform in which 21 obstacles were hidden. Each subject was tripped over one of these obstacles at mid-swing of the left foot in at least five trials. Kinematics, dynamics, and muscle activity of the main trunk muscles were measured. After a trip, an increase in trunk flexion was observed (peak flexion 37 degrees). In addition, considerable movements outside the sagittal plane (up to 20 degrees) occurred. Already before landing of the blocked foot, the trunk forward bending movement was reduced, while trunk torsion and lateral rotation were still increasing. Fast responses were seen in both abdominal and back muscles, indicating stiffening of the trunk. These muscle responses preceded the mechanical trunk disturbances, which implies that these responses were triggered by other mechanisms (such as afferent signals from the extremities) rather than a simple stretch reflex. A second burst of predominantly trunk muscle extensor activity was seen at landing, suggesting specific anticipation of the trunk muscles to minimize trunk movements due to landing. In conclusion, despite large movements outside the sagittal plane, it appears that trunk muscle responses to trips are aspecific and especially aimed at minimizing trunk forward bending.

  16. Integrating arm movement into bridge exercise: Effect on EMG activity of selected trunk muscles.

    PubMed

    Kim, Moung-Jin; Oh, Duck-Won; Park, Hyun-Ju

    2013-10-01

    The purpose of this study was to determine whether incorporating arm movement into bridge exercise changes the electromyographic (EMG) activity of selected trunk muscles. Twenty healthy young men were recruited for this study. EMG data were collected for the rectus abdominis (RA), internal oblique (IO), erector spinae (ES), and multifidus (MF) muscles of the dominant side. During bridging, an experimental procedure was performed with two options: an intervention factor (with and without arm movement) and a bridging factor (on the floor and on a therapeutic ball). There were significant main effects for the intervention factor in the IO and ES and for the bridging factor in the IO. The RA and IO showed significant interaction between the intervention and bridge factors. Furthermore, IO/RA ratio during bridging on the floor (without arm movement, 2.05±2.61; with arm movement, 3.24±3.42) and bridging on the ball (without arm movement: 2.95±3.87; with arm movement: 5.77±4.85) showed significant main effects for, and significant interaction between the intervention and bridge factors. However, no significant main effects or interaction were found for the MF/ES ratio. These findings suggest that integrating arm movements during bridge exercises may be used to provide preferential loading to certain trunk muscle groups and that these effects may be better derived by performing bridge exercises on a therapeutic ball.

  17. Lawyers' attitudes toward involuntary treatment.

    PubMed

    Luchins, Daniel J; Cooper, Amy E; Hanrahan, Patricia; Heyrman, Mark J

    2006-01-01

    This study examined whether lawyers' attributions of responsibility for mental illnesses affect their decisions about involuntary treatment. A survey that was mailed in 2003 to Illinois lawyers involved in involuntary commitment elicited recommendations for involuntary treatment for characters presented in vignettes. The survey also sought respondents' attributions of personal responsibility for the onset and recurrence of mental illnesses. A total of 89 lawyers responded to the survey, a response rate of 48 percent. Decisions to hospitalize persons with mental illness involuntarily increased significantly with the level of risk of harm and were significantly related to attributions of responsibility for the recurrence of mental illness. Decisions to recommend involuntary medication were not related to attributions of responsibility.

  18. Analysis of jaw movements and muscle activity during mastication with JawReports Software.

    PubMed

    John, D; Ruge, S; Kordass, B

    2011-01-01

    We are currently developing new software for simultaneous visualisation and analysis of computerized recorded masticatory function and masticatory muscle activity. With the software, motion data recorded using the Jaw Motion Analyser and EMG data on masseter muscle activity can be uploaded in order to evaluate chewing activity immediately proximal to the occlusal surfaces. The software successfully differentiated between jaw opening and closing movements and filtered out muscle activity peaks, which were graphically depicted in the respective movement trajectories. This tracking strategy made it possible to visualize the movement sectors where chewing forces were effective and to estimate the strength of these forces. In the future, this software should improve our ability to analyze and assess the development of chewing forces. Therefore, it could provide a tool for optimal planning of implant-supported or CAD/CAM restorations.

  19. Prediction of muscle performance during dynamic repetitive movement

    NASA Technical Reports Server (NTRS)

    Byerly, D. L.; Byerly, K. A.; Sognier, M. A.; Squires, W. G.

    2003-01-01

    BACKGROUND: During long-duration spaceflight, astronauts experience progressive muscle atrophy and often perform strenuous extravehicular activities. Post-flight, there is a lengthy recovery period with an increased risk for injury. Currently, there is a critical need for an enabling tool to optimize muscle performance and to minimize the risk of injury to astronauts while on-orbit and during post-flight recovery. Consequently, these studies were performed to develop a method to address this need. METHODS: Eight test subjects performed a repetitive dynamic exercise to failure at 65% of their upper torso weight using a Lordex spinal machine. Surface electromyography (SEMG) data was collected from the erector spinae back muscle. The SEMG data was evaluated using a 5th order autoregressive (AR) model and linear regression analysis. RESULTS: The best predictor found was an AR parameter, the mean average magnitude of AR poles, with r = 0.75 and p = 0.03. This parameter can predict performance to failure as early as the second repetition of the exercise. CONCLUSION: A method for predicting human muscle performance early during dynamic repetitive exercise was developed. The capability to predict performance to failure has many potential applications to the space program including evaluating countermeasure effectiveness on-orbit, optimizing post-flight recovery, and potential future real-time monitoring capability during extravehicular activity.

  20. Prediction of muscle performance during dynamic repetitive movement

    NASA Technical Reports Server (NTRS)

    Byerly, D. L.; Byerly, K. A.; Sognier, M. A.; Squires, W. G.

    2003-01-01

    BACKGROUND: During long-duration spaceflight, astronauts experience progressive muscle atrophy and often perform strenuous extravehicular activities. Post-flight, there is a lengthy recovery period with an increased risk for injury. Currently, there is a critical need for an enabling tool to optimize muscle performance and to minimize the risk of injury to astronauts while on-orbit and during post-flight recovery. Consequently, these studies were performed to develop a method to address this need. METHODS: Eight test subjects performed a repetitive dynamic exercise to failure at 65% of their upper torso weight using a Lordex spinal machine. Surface electromyography (SEMG) data was collected from the erector spinae back muscle. The SEMG data was evaluated using a 5th order autoregressive (AR) model and linear regression analysis. RESULTS: The best predictor found was an AR parameter, the mean average magnitude of AR poles, with r = 0.75 and p = 0.03. This parameter can predict performance to failure as early as the second repetition of the exercise. CONCLUSION: A method for predicting human muscle performance early during dynamic repetitive exercise was developed. The capability to predict performance to failure has many potential applications to the space program including evaluating countermeasure effectiveness on-orbit, optimizing post-flight recovery, and potential future real-time monitoring capability during extravehicular activity.

  1. Computational Modelling and Movement Analysis of Hip Joint with Muscles

    NASA Astrophysics Data System (ADS)

    Siswanto, W. A.; Yoon, C. C.; Salleh, S. Md.; Ngali, M. Z.; Yusup, Eliza M.

    2017-01-01

    In this study, the model of hip joint and the main muscles are modelled by finite elements. The parts included in the model are hip joint, hemi pelvis, gluteus maximus, quadratus femoris and gamellus inferior. The materials that used in these model are isotropic elastic, Mooney Rivlin and Neo-hookean. The hip resultant force of the normal gait and stair climbing are applied on the model of hip joint. The responses of displacement, stress and strain of the muscles are then recorded. FEBio non-linear solver for biomechanics is employed to conduct the simulation of the model of hip joint with muscles. The contact interfaces that used in this model are sliding contact and tied contact. From the analysis results, the gluteus maximus has the maximum displacement, stress and strain in the stair climbing. Quadratus femoris and gamellus inferior has the maximum displacement and strain in the normal gait however the maximum stress in the stair climbing. Besides that, the computational model of hip joint with muscles is produced for research and investigation platform. The model can be used as a visualization platform of hip joint.

  2. Pharmacological studies of charge movement in frog skeletal muscle.

    PubMed

    Hui, C S

    1983-04-01

    Charge movements in frog twitch fibres were studied using the three-microelectrode voltage-clamp technique. In a solution made moderately hypertonic with 350 mM-sucrose, fibre contraction was effectively blocked and a secondary hump appeared in the decay phase of the 'on' part of charge movement. At small depolarizations, the hump (Q gamma) is small and slow. As depolarization is increased, Q gamma becomes larger in magnitude and faster in kinetics until it merges with the main part of charge movement (Q beta). As the fibre is perfused extracellularly with a test solution saturated with dantrolene sodium, Q gamma disappears in about 30 min whereas the kinetics of Q beta are slowed down. After equilibration in the dantrolene sodium solution, the total moveable charge is reduced by about 20%, which could very well be the charge carried by Q gamma. Tetracaine also suppresses Q gamma but does not seem to have any effect on the kinetics of Q beta. The suppression of Q gamma appears to be dose-dependent, with complete abolition occurring at about 4 mM-tetracaine. Dissection of charge movement with tetracaine indicates that Q gamma might be bell-shaped and capacitive in nature. Q beta and Q gamma might be two distinct species of charge and Q gamma would probably be more closely associated with calcium release from the sarcoplasmic reticulum.

  3. Pharmacological studies of charge movement in frog skeletal muscle.

    PubMed Central

    Hui, C S

    1983-01-01

    Charge movements in frog twitch fibres were studied using the three-microelectrode voltage-clamp technique. In a solution made moderately hypertonic with 350 mM-sucrose, fibre contraction was effectively blocked and a secondary hump appeared in the decay phase of the 'on' part of charge movement. At small depolarizations, the hump (Q gamma) is small and slow. As depolarization is increased, Q gamma becomes larger in magnitude and faster in kinetics until it merges with the main part of charge movement (Q beta). As the fibre is perfused extracellularly with a test solution saturated with dantrolene sodium, Q gamma disappears in about 30 min whereas the kinetics of Q beta are slowed down. After equilibration in the dantrolene sodium solution, the total moveable charge is reduced by about 20%, which could very well be the charge carried by Q gamma. Tetracaine also suppresses Q gamma but does not seem to have any effect on the kinetics of Q beta. The suppression of Q gamma appears to be dose-dependent, with complete abolition occurring at about 4 mM-tetracaine. Dissection of charge movement with tetracaine indicates that Q gamma might be bell-shaped and capacitive in nature. Q beta and Q gamma might be two distinct species of charge and Q gamma would probably be more closely associated with calcium release from the sarcoplasmic reticulum. PMID:6603512

  4. Differential contributions of vision, touch and muscle proprioception to the coding of hand movements.

    PubMed

    Blanchard, Caroline; Roll, Régine; Roll, Jean-Pierre; Kavounoudias, Anne

    2013-01-01

    To further elucidate the mechanisms underlying multisensory integration, this study examines the controversial issue of whether congruent inputs from three different sensory sources can enhance the perception of hand movement. Illusory sensations of clockwise rotations of the right hand were induced by either separately or simultaneously stimulating visual, tactile and muscle proprioceptive channels at various intensity levels. For this purpose, mechanical vibrations were applied to the pollicis longus muscle group in the subjects' wrists, and a textured disk was rotated under the palmar skin of the subjects' right hands while a background visual scene was projected onto the rotating disk. The elicited kinaesthetic illusions were copied by the subjects in real time and the EMG activity in the adductor and abductor wrist muscles was recorded. The results show that the velocity of the perceived movements and the amplitude of the corresponding motor responses were modulated by the nature and intensity of the stimulation. Combining two sensory modalities resulted in faster movement illusions, except for the case of visuo-tactile co-stimulation. When a third sensory input was added to the bimodal combinations, the perceptual responses increased only when a muscle proprioceptive stimulation was added to a visuo-tactile combination. Otherwise, trisensory stimulation did not override bimodal conditions that already included a muscle proprioceptive stimulation. We confirmed that vision or touch alone can encode the kinematic parameters of hand movement, as is known for muscle proprioception. When these three sensory modalities are available, they contribute unequally to kinaesthesia. In addition to muscle proprioception, the complementary kinaesthetic content of visual or tactile inputs may optimize the velocity estimation of an on-going movement, whereas the redundant kinaesthetic content of the visual and tactile inputs may rather enhance the latency of the perception.

  5. Proprioceptive regulation of voluntary ankle movements, demonstrated using muscle vibration, is impaired by Parkinson's disease

    PubMed Central

    Khudados, E.; Cody, F.; O'Boyle, D.

    1999-01-01

    OBJECTIVE—To test the hypothesis that the proprioceptive regulation of voluntary movement is disturbed by Parkinson's disease, the effects of experimental stimulation of proprioceptors, using muscle vibration, on the trajectories of voluntary dorsiflexion movements of the ankle joint were compared between parkinsonian and control subjects.
METHODS—Twenty one patients with Parkinson's disease, on routine medication (levodopa in all but one), and an equal number of age matched, neurologically intact controls, were trained initially to make reproducible ankle dorsiflexion movements (20° amplitude with a velocity of 9.7°/s) following a visual "go" cue while movement trajectories were recorded goniometrically. During 50% of the experimental trials, vibration (105 Hz; 0.7 mm peak to peak) was applied to the Achilles tendon during the ankle movement to stimulate antagonist muscle spindles; vibrated and non-vibrated trials were interspersed randomly. Subjects' performance was assessed by measuring end point position—that is, the ankle angle attained 2 seconds after the visual "go" cue, from averaged (20 trials) trajectories.
RESULTS—Statistical analysis of the end point amplitudes of movement showed that, whereas the amplitudes of non-vibrated movements did not differ significantly between patients with Parkinson's disease and controls, antagonist muscle vibration produced a highly significant reduction in the amplitudes of ankle dorsiflexion movements in both the patient and control groups. However, the extent of vibration induced undershooting produced in the patients with Parkinson's disease was significantly less than that in the controls; the mean vibrated/non-vibrated ratios were 0.86 and 0.54 for, respectively, the patient and control groups.
CONCLUSIONS—The present finding of a reduction of vibration induced ankle movement errors in parkinsonian patients resembles qualitatively previous observations of wrist movements, and suggests that Parkinson

  6. Association of orofacial muscle activity and movement during changes in speech rate and intensity.

    PubMed

    McClean, Michael D; Tasko, Stephen M

    2003-12-01

    Understanding how orofacial muscle activity and movement covary across changes in speech rate and intensity has implications for the neural control of speech production and the use of clinical procedures that manipulate speech prosody. The present study involved a correlation analysis relating average lower-lip and jaw-muscle activity to lip and jaw movement distance, speed, and duration. Recordings were obtained on orofacial movement, muscle activity, and the acoustic signal in 3 normal speakers as they repeated a simple test utterance with targeted speech rates varying from 60% to 160% of their habitual rate and at targeted vocal intensities of -6 dB and +6 dB relative to their habitual intensity. Surface electromyographic (EMG) recordings were obtained with electrodes positioned to sample primarily the mentalis, depressor labii inferior, anterior belly of the digastric, and masseter muscles. Two-dimensional displacements of the lower lip and jaw in the midsagittal plane were recorded with an electromagnetic system. All participants produced linear changes in percent utterance duration relative to the auditory targets for speech rate variation. Intensity variations ranged from -10 dB to +8 dB. Average EMG levels for all 4 muscles were well correlated with specific parameters of movement. Across the intensity conditions, EMG level was positively correlated with movement speed and distance in all participants. Across the rate conditions, EMG level was negatively correlated with movement duration in all participants, while greater interparticipant variability was noted for correlations relating EMG to speed and distance. For intensity control, it is suggested that converging neural input to orofacial motoneurons varies monotonically with movement distance and speed. In contrast, rate control appears to be more strongly related to the temporal characteristics of neural input than activation level.

  7. The role of muscle spindles in ankle movement perception in human subjects with diabetic neuropathy.

    PubMed

    van Deursen, R W; Sanchez, M M; Ulbrecht, J S; Cavanagh, P R

    1998-05-01

    The objective of this study was to develop a quantitative method to assess muscle spindle function. Three groups of subjects were studied: ten young and healthy subjects, 15 older subjects with diabetic neuropathy, and 15 age-matched controls. All subjects performed an ankle-movement matching task with and without muscle vibration. Input from the plantar cutaneous mechanoreceptors was minimized by using a foot-clamping device. The younger subjects tracked the movement very well, but vibration had a significant effect on their performance (P < 0.001). Similar results were seen in the older control subjects, but they were less successful in tracking movement and slightly less affected by vibration. The neuropathic subjects had the most difficulty tracking, and vibration had only a small but still significant effect on their performance. The interaction between the group and the vibration effect was highly significant (P < 0.001), indicating that the performance of the control subjects changed to a greater degree in the presence of vibration than the performance of the subjects with diabetic neuropathy. Muscle spindles are the primary receptors that are involved in the change in tracking performance when vibration is added during an ankle-movement matching task, and we therefore conclude that the procedure described provides a quantitative evaluation of muscle spindle function. The results demonstrate that diabetic neuropathy degrades muscle sensory function, which may contribute to the impaired balance and unsteadiness of gait that has been observed in diabetic neuropathy.

  8. A Real-Time Fatigue Monitoring and Analysis System for Lower Extremity Muscles with Cycling Movement

    PubMed Central

    Chen, Szi-Wen; Liaw, Jiunn-Woei; Chan, Hsiao-Lung; Chang, Ya-Ju; Ku, Chia-Hao

    2014-01-01

    A real-time muscle fatigue monitoring system was developed to quantitatively detect the muscle fatigue of subjects during cycling movement, where a fatigue progression measure (FPM) was built-in. During the cycling movement, the electromyogram (EMG) signals of the vastus lateralis and gastrocnemius muscles in one leg as well as cycling speed are synchronously measured in a real-time fashion. In addition, the heart rate (HR) and the Borg rating of perceived exertion scale value are recorded per minute. Using the EMG signals, the electrical activity and median frequency (MF) are calculated per cycle. Moreover, the updated FPM, based on the percentage of reduced MF counts during cycling movement, is calculated to measure the onset time and the progressive process of muscle fatigue. To demonstrate the performance of our system, five young healthy subjects were recruited. Each subject was asked to maintain a fixed speed of 60 RPM, as best he/she could, under a constant load during the pedaling. When the speed reached 20 RPM or the HR reached the maximal training HR, the experiment was then terminated immediately. The experimental results show that the proposed system may provide an on-line fatigue monitoring and analysis for the lower extremity muscles during cycling movement. PMID:25014101

  9. Characterization of Involuntary Contractions after Spinal Cord Injury Reveals Associations between Physiological and Self-Reported Measures of Spasticity

    PubMed Central

    Mayo, Meagan; DeForest, Bradley A.; Castellanos, Mabelin; Thomas, Christine K.

    2017-01-01

    Correlations between physiological, clinical and self-reported assessments of spasticity are often weak. Our aims were to quantify functional, self-reported and physiological indices of spasticity in individuals with thoracic spinal cord injury (SCI; 3 women, 9 men; 19–52 years), and to compare the strength and direction of associations between these measures. The functional measure we introduced involved recording involuntary electromyographic activity during a transfer from wheelchair to bed which is a daily task necessary for function. High soleus (SL) and tibialis anterior (TA) F-wave/M-wave area ratios were the only physiological measures that distinguished injured participants from the uninjured (6 women, 13 men, 19–67 years). Hyporeflexia (decreased SL H/M ratio) was unexpectedly present in older participants after injury. During transfers, the duration and intensity of involuntary electromyographic activity varied across muscles and participants, but coactivity was common. Wide inter-participant variability was seen for self-reported spasm frequency, severity, pain and interference with function, as well as tone (resistance to imposed joint movement). Our recordings of involuntary electromyographic activity during transfers provided evidence of significant associations between physiological and self-reported measures of spasticity. Reduced low frequency H-reflex depression in SL and high F-wave/M-wave area ratios in TA, physiological indicators of reduced inhibition and greater motoneuron excitability, respectively, were associated with long duration SL and biceps femoris (BF) electromyographic activity during transfers. In turn, participants reported high spasm frequency when transfers involved short duration TA EMG, decreased co-activation between SL and TA, as well as between rectus femoris (RF) vs. BF. Thus, the duration of muscle activity and/or the time of agonist-antagonist muscle coactivity may be used by injured individuals to count spasms

  10. Characterization of Involuntary Contractions after Spinal Cord Injury Reveals Associations between Physiological and Self-Reported Measures of Spasticity.

    PubMed

    Mayo, Meagan; DeForest, Bradley A; Castellanos, Mabelin; Thomas, Christine K

    2017-01-01

    Correlations between physiological, clinical and self-reported assessments of spasticity are often weak. Our aims were to quantify functional, self-reported and physiological indices of spasticity in individuals with thoracic spinal cord injury (SCI; 3 women, 9 men; 19-52 years), and to compare the strength and direction of associations between these measures. The functional measure we introduced involved recording involuntary electromyographic activity during a transfer from wheelchair to bed which is a daily task necessary for function. High soleus (SL) and tibialis anterior (TA) F-wave/M-wave area ratios were the only physiological measures that distinguished injured participants from the uninjured (6 women, 13 men, 19-67 years). Hyporeflexia (decreased SL H/M ratio) was unexpectedly present in older participants after injury. During transfers, the duration and intensity of involuntary electromyographic activity varied across muscles and participants, but coactivity was common. Wide inter-participant variability was seen for self-reported spasm frequency, severity, pain and interference with function, as well as tone (resistance to imposed joint movement). Our recordings of involuntary electromyographic activity during transfers provided evidence of significant associations between physiological and self-reported measures of spasticity. Reduced low frequency H-reflex depression in SL and high F-wave/M-wave area ratios in TA, physiological indicators of reduced inhibition and greater motoneuron excitability, respectively, were associated with long duration SL and biceps femoris (BF) electromyographic activity during transfers. In turn, participants reported high spasm frequency when transfers involved short duration TA EMG, decreased co-activation between SL and TA, as well as between rectus femoris (RF) vs. BF. Thus, the duration of muscle activity and/or the time of agonist-antagonist muscle coactivity may be used by injured individuals to count spasms. Intense

  11. Complex muscle vibration patterns to induce gait-like lower-limb movements: proof of concept.

    PubMed

    Duclos, Cyril; Kemlin, Claire; Lazert, David; Gagnon, Dany; Dyer, Joseph-Omer; Forget, Robert

    2014-01-01

    Muscle vibrations can induce motor responses and illusions of complex movements. However, inducing gait-like cyclical movements and illusions requires the application of multiple fast alternating vibrations to lower-limb muscles. The objectives were (1) to test the feasibility of delivering complex vibrations in a time-organized manner and (2) to illustrate the possibility of inducing alternate gait-in-place-like movements using these vibrations. Patterns of vibration, produced by 12 vibrators applied bilaterally on the flexor and extensor muscle groups of the lower limbs, were based on normal gait kinematics. We tested 1 s and 2 s cycle patterns of vibration. Vibrator responses were assessed using auto- and crosscorrelations and frequency analyses based on accelerometry measurements, and compared between patterns. High auto- (>0.8) and crosscorrelation (>0.6) coefficients demonstrated a good response by the vibrators to the control signal. Vibrations induced cyclical, low-amplitude stepping-in-place movements that mimicked alternate walking movements with both legs, with 1 s and 2 s cycle durations, in one nondisabled participant and one participant with American Spinal Injury Association Impairment Scale B spinal cord injury standing, relaxed, with body-weight support. Electromechanical vibrators can deliver complex cyclical vibrations and trigger gait-like lower-limb movements. These results warrant the application of these vibration patterns on individuals with sensorimotor impairments to test their potential in gait rehabilitation.

  12. Arm position influences the activation patterns of trunk muscles during trunk range-of-motion movements.

    PubMed

    Siu, Aaron; Schinkel-Ivy, Alison; Drake, Janessa Dm

    2016-10-01

    To understand the activation patterns of the trunk musculature, it is also important to consider the implications of adjacent structures such as the upper limbs, and the muscles that act to move the arms. This study investigated the effects of arm positions on the activation patterns and co-activation of the trunk musculature and muscles that move the arm during trunk range-of-motion movements (maximum trunk axial twist, flexion, and lateral bend). Fifteen males and fifteen females, asymptomatic for low back pain, performed maximum trunk range-of-motion movements, with three arm positions for axial twist (loose, crossed, abducted) and two positions for flexion and lateral bend (loose, crossed). Electromyographical data were collected for eight muscles bilaterally, and activation signals were cross-correlated between trunk muscles and the muscles that move the arms (upper trapezius, latissimus dorsi). Results revealed consistently greater muscle co-activation (higher cross-correlation coefficients) between the trunk muscles and upper trapezius for the abducted arm position during maximum trunk axial twist, while results for the latissimus dorsi-trunk pairings were more dependent on the specific trunk muscles (either abdominal or back) and latissimus dorsi muscle (either right or left side), as well as the range-of-motion movement. The findings of this study contribute to the understanding of interactions between the upper limbs and trunk, and highlight the influence of arm positions on the trunk musculature. In addition, the comparison of the present results to those of individuals with back or shoulder conditions may ultimately aid in elucidating underlying mechanisms or contributing factors to those conditions.

  13. Dystonia redefined as central non-paretic loss of control of muscle action: a concept including inability to activate muscles required for a specific movement, or 'negative dystonia'.

    PubMed

    Mezaki, Takahiro

    2007-01-01

    Dystonia is defined as a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements, or abnormal postures. Although this definition comprises an essential feature of dystonia, the clinical observation indicates that there is an additional aspect of dystonia; failure to adequately activate muscles required for specific movement, exemplified by the lack of contractions of the levator palpebrae superioris muscles in apraxia of lid opening, as well as by inability to activate appropriate muscles in cervical dystonia or in the paretic form of writer's cramp, and possibly by dropped head syndrome or camptocormia seen in parkinsonian patients without apparent truncal dystonia or rigidity. Taking this "negative dystonia" into consideration, the author proposes a revised definition of dystonia as a symptom characterized by the central non-paretic loss of voluntary control of muscle activities, which may result in either excessive or deficient contractions of muscles, frequently causing twisting and repetitive movements, limitation of movements, or abnormal postures.

  14. A Comparison of Muscle Activity in Concentric and Counter Movement Maximum Bench Press

    PubMed Central

    van den Tillaar, Roland; Ettema, Gertjan

    2013-01-01

    The purpose of this study was to compare the kinematics and muscle activation patterns of regular free-weight bench press (counter movement) with pure concentric lifts in the ascending phase of a successful one repetition maximum (1-RM) attempt in the bench press. Our aim was to evaluate if diminishing potentiation could be the cause of the sticking region. Since diminishing potentiation cannot occur in pure concentric lifts, the occurrence of a sticking region in this type of muscle actions would support the hypothesis that the sticking region is due to a poor mechanical position. Eleven male participants (age 21.9 ± 1.7 yrs, body mass 80.7 ± 10.9 kg, body height 1.79 ± 0.07 m) conducted 1-RM lifts in counter movement and in pure concentric bench presses in which kinematics and EMG activity were measured. In both conditions, a sticking region occurred. However, the start of the sticking region was different between the two bench presses. In addition, in four of six muscles, the muscle activity was higher in the counter movement bench press compared to the concentric one. Considering the findings of the muscle activity of six muscles during the maximal lifts it was concluded that the diminishing effect of force potentiation, which occurs in the counter movement bench press, in combination with a delayed muscle activation unlikely explains the existence of the sticking region in a 1-RM bench press. Most likely, the sticking region is the result of a poor mechanical force position. PMID:24235985

  15. Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies.

    PubMed

    Chiovetto, Enrico; Berret, Bastien; Delis, Ioannis; Panzeri, Stefano; Pozzo, Thierry

    2013-01-01

    A long standing hypothesis in the neuroscience community is that the central nervous system (CNS) generates the muscle activities to accomplish movements by combining a relatively small number of stereotyped patterns of muscle activations, often referred to as "muscle synergies." Different definitions of synergies have been given in the literature. The most well-known are those of synchronous, time-varying and temporal muscle synergies. Each one of them is based on a different mathematical model used to factor some EMG array recordings collected during the execution of variety of motor tasks into a well-determined spatial, temporal or spatio-temporal organization. This plurality of definitions and their separate application to complex tasks have so far complicated the comparison and interpretation of the results obtained across studies, and it has always remained unclear why and when one synergistic decomposition should be preferred to another one. By using well-understood motor tasks such as elbow flexions and extensions, we aimed in this study to clarify better what are the motor features characterized by each kind of decomposition and to assess whether, when and why one of them should be preferred to the others. We found that three temporal synergies, each one of them accounting for specific temporal phases of the movements could account for the majority of the data variation. Similar performances could be achieved by two synchronous synergies, encoding the agonist-antagonist nature of the two muscles considered, and by two time-varying muscle synergies, encoding each one a task-related feature of the elbow movements, specifically their direction. Our findings support the notion that each EMG decomposition provides a set of well-interpretable muscle synergies, identifying reduction of dimensionality in different aspects of the movements. Taken together, our findings suggest that all decompositions are not equivalent and may imply different neurophysiological

  16. A comparison of muscle activity in concentric and counter movement maximum bench press.

    PubMed

    van den Tillaar, Roland; Ettema, Gertjan

    2013-01-01

    The purpose of this study was to compare the kinematics and muscle activation patterns of regular free-weight bench press (counter movement) with pure concentric lifts in the ascending phase of a successful one repetition maximum (1-RM) attempt in the bench press. Our aim was to evaluate if diminishing potentiation could be the cause of the sticking region. Since diminishing potentiation cannot occur in pure concentric lifts, the occurrence of a sticking region in this type of muscle actions would support the hypothesis that the sticking region is due to a poor mechanical position. Eleven male participants (age 21.9 ± 1.7 yrs, body mass 80.7 ± 10.9 kg, body height 1.79 ± 0.07 m) conducted 1-RM lifts in counter movement and in pure concentric bench presses in which kinematics and EMG activity were measured. In both conditions, a sticking region occurred. However, the start of the sticking region was different between the two bench presses. In addition, in four of six muscles, the muscle activity was higher in the counter movement bench press compared to the concentric one. Considering the findings of the muscle activity of six muscles during the maximal lifts it was concluded that the diminishing effect of force potentiation, which occurs in the counter movement bench press, in combination with a delayed muscle activation unlikely explains the existence of the sticking region in a 1-RM bench press. Most likely, the sticking region is the result of a poor mechanical force position.

  17. Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies

    PubMed Central

    Chiovetto, Enrico; Berret, Bastien; Delis, Ioannis; Panzeri, Stefano; Pozzo, Thierry

    2013-01-01

    A long standing hypothesis in the neuroscience community is that the central nervous system (CNS) generates the muscle activities to accomplish movements by combining a relatively small number of stereotyped patterns of muscle activations, often referred to as “muscle synergies.” Different definitions of synergies have been given in the literature. The most well-known are those of synchronous, time-varying and temporal muscle synergies. Each one of them is based on a different mathematical model used to factor some EMG array recordings collected during the execution of variety of motor tasks into a well-determined spatial, temporal or spatio-temporal organization. This plurality of definitions and their separate application to complex tasks have so far complicated the comparison and interpretation of the results obtained across studies, and it has always remained unclear why and when one synergistic decomposition should be preferred to another one. By using well-understood motor tasks such as elbow flexions and extensions, we aimed in this study to clarify better what are the motor features characterized by each kind of decomposition and to assess whether, when and why one of them should be preferred to the others. We found that three temporal synergies, each one of them accounting for specific temporal phases of the movements could account for the majority of the data variation. Similar performances could be achieved by two synchronous synergies, encoding the agonist-antagonist nature of the two muscles considered, and by two time-varying muscle synergies, encoding each one a task-related feature of the elbow movements, specifically their direction. Our findings support the notion that each EMG decomposition provides a set of well-interpretable muscle synergies, identifying reduction of dimensionality in different aspects of the movements. Taken together, our findings suggest that all decompositions are not equivalent and may imply different neurophysiological

  18. Internal kinematics of the tongue in relation to muscle activity and jaw movement in the pig.

    PubMed

    Liu, Z-J; Shcherbatyy, V; Kayalioglu, M; Seifi, A

    2009-09-01

    To explore the coordinative characteristics of tongue deformation, muscle activity and jaw movement during feeding, six ultrasonic crystals were implanted into the tongue body of ten 12-week-old Yucatan minipigs 1 week before the recording. These crystals formed a wedge-shaped configuration to allow recording dimensional changes in lengths, anterior and posterior widths and posterior thicknesses of the tongue body during feeding. Wire electromyographic activities (EMG) of superior and inferior longitudinalis, verticalis/transversus, genioglossus, styloglossus, masseter and digastricus and jaw movements were recorded simultaneously. Signals from these three sources were synchronized for real-time analyses. The results indicate: (i) dimensional changes were stereotypical in relation to each cycle of all three feeding behaviours; (ii) during chewing, expansion of tongue widths mainly occurred in the occlusal phase of jaw movement and was less coupled with the activity of tongue muscles, but the expansions of length and thickness were seen in the opening and closing phases and were better coupled with the activity of tongue muscles (P < 0.05); (iii) ingestion was characterized by the two-phased jaw opening, early expansion of anterior width prior to the occlusal phase and strong associations between tongue deformation and muscle activity; (iv) during drinking, the duration of the opening and closing phases was significantly prolonged (P < 0.01), the durations of tongue widening and lengthening were significantly shortened (P < 0.05) and anterior widening was predominant in the opening rather than in the closing or occlusal phases as compared with chewing and ingestion; and (v) the intrinsic tongue muscles did not show more or stronger correlations with the tongue deformation than did the extrinsic tongue muscles. These results suggest that (i) regional widening, lengthening and thickening of the tongue body occurs sequentially in relation to jaw movement phases, but

  19. Internal kinematics of the tongue in relation to muscle activity and jaw movement in the pig

    PubMed Central

    LIU, Z.-J.; SHCHERBATYY, V.; KAYALIOGLU, M.; SEIFI, A.

    2012-01-01

    SUMMARY To explore the coordinative characteristics of tongue deformation, muscle activity and jaw movement during feeding, six ultrasonic crystals were implanted into the tongue body of ten 12-week-old Yucatan minipigs 1 week before the recording. These crystals formed a wedge-shaped configuration to allow recording dimensional changes in lengths, anterior and posterior widths and posterior thicknesses of the tongue body during feeding. Wire electromyographic activities (EMG) of superior and inferior longitudinalis, verticalis/transversus, genioglossus, styloglossus, masseter and digastricus and jaw movements were recorded simultaneously. Signals from these three sources were synchronized for real-time analyses. The results indicate: (i) dimensional changes were stereotypical in relation to each cycle of all three feeding behaviours; (ii) during chewing, expansion of tongue widths mainly occurred in the occlusal phase of jaw movement and was less coupled with the activity of tongue muscles, but the expansions of length and thickness were seen in the opening and closing phases and were better coupled with the activity of tongue muscles (P < 0·05); (iii) ingestion was characterized by the two-phased jaw opening, early expansion of anterior width prior to the occlusal phase and strong associations between tongue deformation and muscle activity; (iv) during drinking, the duration of the opening and closing phases was significantly prolonged (P < 0·01), the durations of tongue widening and lengthening were significantly shortened (P < 0·05) and anterior widening was predominant in the opening rather than in the closing or occlusal phases as compared with chewing and ingestion; and (v) the intrinsic tongue muscles did not show more or stronger correlations with the tongue deformation than did the extrinsic tongue muscles. These results suggest that (i) regional widening, lengthening and thickening of the tongue body occurs sequentially in relation to jaw movement

  20. [Masticatory muscles. Part VI. Masticatory muscles and movement of the lower jaw].

    PubMed

    Naeije, M

    1997-12-01

    The movement paths of the kinematic center of the temporomandibular joint were recorded by means of a jaw movement recording system (OKAS-3D) under 3 conditions: 1. free open and close movements; 2. free opening and loaded closing movements (subjects closed against a small, manually applied, downward directed force on the chin); and 3. during chewing of chewing gum. During free jaw movements, the opening path of the kinematic center lies above the closing path. During loaded closing movements, the opening and closing paths coincide. This indicates that during opening and loaded closing, the condyle-disc complex is slightly pressed against the articular eminence. However, during free closing, there is more space between the articulating surfaces. During gum chewing, the opening and closing paths of the condyle coincide on the balancing side, on the working side they don't. Thus, the joint on the balancing side is loaded and the joint on the working side is not.

  1. Economy, Movement Dynamics, and Muscle Activity of Human Walking at Different Speeds

    PubMed Central

    Raffalt, P. C.; Guul, M. K.; Nielsen, A. N.; Puthusserypady, S.; Alkjær, T.

    2017-01-01

    The complex behaviour of human walking with respect to movement variability, economy and muscle activity is speed dependent. It is well known that a U-shaped relationship between walking speed and economy exists. However, it is an open question if the movement dynamics of joint angles and centre of mass and muscle activation strategy also exhibit a U-shaped relationship with walking speed. We investigated the dynamics of joint angle trajectories and the centre of mass accelerations at five different speeds ranging from 20 to 180% of the predicted preferred speed (based on Froude speed) in twelve healthy males. The muscle activation strategy and walking economy were also assessed. The movement dynamics was investigated using a combination of the largest Lyapunov exponent and correlation dimension. We observed an intermediate stage of the movement dynamics of the knee joint angle and the anterior-posterior and mediolateral centre of mass accelerations which coincided with the most energy-efficient walking speed. Furthermore, the dynamics of the joint angle trajectories and the muscle activation strategy was closely linked to the functional role and biomechanical constraints of the joints. PMID:28272484

  2. Evaluation of document location during computer use in terms of neck muscle activity and neck movement.

    PubMed

    Goostrey, Sonya; Treleaven, Julia; Johnston, Venerina

    2014-05-01

    This study evaluated the impact on neck movement and muscle activity of placing documents in three commonly used locations: in-line, flat desktop left of the keyboard and laterally placed level with the computer screen. Neck excursion during three standard head movements between the computer monitor and each document location and neck extensor and upper trapezius muscle activity during a 5 min typing task for each of the document locations was measured in 20 healthy participants. Results indicated that muscle activity and neck flexion were least when documents were placed laterally suggesting it may be the optimal location. The desktop option produced both the greatest neck movement and muscle activity in all muscle groups. The in-line document location required significantly more neck flexion but less lateral flexion and rotation than the laterally placed document. Evaluation of other holders is needed to guide decision making for this commonly used office equipment. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  3. NEUROMUSCULAR ELECTRICAL STIMULATION OF THE HINDLIMB MUSCLES FOR MOVEMENT THERAPY IN A RODENT MODEL

    PubMed Central

    Ichihara, Kazuhiko; Venkatasubramanian, Ganapriya; Abbas, James J.; Jung, Ranu

    2009-01-01

    Neuromuscular electrical stimulation (NMES) can provide functional movements in people after central nervous system injury. The neuroplastic effects of long-term NMES induced repetitive limb movement are not well understood. A rodent model of neurotrauma in which NMES can be implemented may be effective for such investigations. We present a rodent model for NMES of the flexor and extensor muscles of the hip, knee, and ankle hindlimb muscles. Custom fabricated intramuscular stimulating electrodes for rodents were implanted near identified motor points of targeted muscles in ten adult, female Long Evans rats. The effects of altering NMES pulse stimulation parameters were characterized using strength duration curves, isometric joint torque recruitment curves and joint angle measures. The data indicate that short pulse widths have the advantage of producing graded torque recruitment curves when current is used as the control parameter. A stimulus frequency of 75Hz or more produces fused contractions. The data demonstrate ability to accurately implant the electrodes and obtain selective, graded, repeatable, strong muscle contractions. Knee and ankle angular excursions comparable to those obtained in normal treadmill walking in the same rodent species can be obtained by stimulating the target muscles. Joint torques (normalized to body weight) obtained were larger than those reported in the literature for small tailed therian mammals and for peak isometric ankle plantarflexion in a different rodent species. This model system could be used for investigations of NMES assisted hindlimb movement therapy. PMID:18848960

  4. Simulation of dynamic orofacial movements using a constitutive law varying with muscle activation.

    PubMed

    Nazari, Mohammad Ali; Perrier, Pascal; Chabanas, Matthieu; Payan, Yohan

    2010-08-01

    This paper presents a biomechanical model of the face to simulate orofacial movements in speech and non-verbal communication. A 3D finite element model, based on medical images of a subject, is presented. A hyperelastic Mooney-Rivlin constitutive law accounts for the non-linear behaviour of facial tissue. Muscle fibres are represented by piece-wise uniaxial tensile element that generate force. The stress stiffening effect, an increase in the stiffness of the muscles when activated, is modelled by varying the constitutive law of the tissue with the level of activation of the muscle. A large number of facial movements occurring during speech and facial mimics are simulated. Results show that our modelling approach provides a realistic account of facial mimics. The differences between dynamic vs. quasi-static simulations are also discussed, proving that dynamic trajectories better fit experimental data.

  5. Myofibril contraction and crosslinking drive nuclear movement to the periphery of skeletal muscle.

    PubMed

    Roman, William; Martins, João P; Carvalho, Filomena A; Voituriez, Raphael; Abella, Jasmine V G; Santos, Nuno C; Cadot, Bruno; Way, Michael; Gomes, Edgar R

    2017-10-01

    Nuclear movements are important for multiple cellular functions, and are driven by polarized forces generated by motor proteins and the cytoskeleton. During skeletal myofibre formation or regeneration, nuclei move from the centre to the periphery of the myofibre for proper muscle function. Centrally located nuclei are also found in different muscle disorders. Using theoretical and experimental approaches, we demonstrate that nuclear movement to the periphery of myofibres is mediated by centripetal forces around the nucleus. These forces arise from myofibril contraction and crosslinking that 'zip' around the nucleus in combination with tight regulation of nuclear stiffness by lamin A/C. In addition, an Arp2/3 complex containing Arpc5L together with γ-actin is required to organize desmin to crosslink myofibrils for nuclear movement. Our work reveals that centripetal forces exerted by myofibrils squeeze the nucleus to the periphery of myofibres.

  6. Task-specific stability in muscle activation space during unintentional movements.

    PubMed

    Falaki, Ali; Towhidkhah, Farzad; Zhou, Tao; Latash, Mark L

    2014-11-01

    We used robot-generated perturbations applied during position-holding tasks to explore stability of induced unintentional movements in a multidimensional space of muscle activations. Healthy subjects held the handle of a robot against a constant bias force and were instructed not to interfere with hand movements produced by changes in the external force. Transient force changes were applied leading to handle displacement away from the initial position and then back toward the initial position. Intertrial variance in the space of muscle modes (eigenvectors in the muscle activations space) was quantified within two subspaces, corresponding to unchanged handle coordinate and to changes in the handle coordinate. Most variance was confined to the former subspace in each of the three phases of movement, the initial steady state, the intermediate position, and the final steady state. The same result was found when the changes in muscle activation were analyzed between the initial and final steady states. Changes in the dwell time between the perturbation force application and removal led to different final hand locations undershooting the initial position. The magnitude of the undershot scaled with the dwell time, while the structure of variance in the muscle activation space did not depend on the dwell time. We conclude that stability of the hand coordinate is ensured during both intentional and unintentional actions via similar mechanisms. Relative equifinality in the external space after transient perturbations may be associated with varying states in the redundant space of muscle activations. The results fit a hierarchical scheme for the control of voluntary movements with referent configurations and redundant mapping between the levels of the hierarchy.

  7. TASK-SPECIFIC STABILITY IN MUSCLE ACTIVATION SPACE DURING UNINTENTIONAL MOVEMENTS

    PubMed Central

    Falaki, Ali; Towhidkhah, Farzad; Zhou, Tao; Latash, Mark L.

    2014-01-01

    We used robot-generated perturbations applied during position-holding tasks to explore stability of induced unintentional movements in a multi-dimensional space of muscle activations. Healthy subjects held the handle of a robot against a constant bias force and were instructed not to interfere with hand movements produced by changes in the external force. Transient force changes were applied leading to handle displacement away from the initial position and then back towards the initial position. Inter-trial variance in the space of muscle modes (eigenvectors in the muscle activations space) was quantified within two sub-spaces, corresponding to unchanged handle coordinate and to changes in the handle coordinate. Most variance was confined to the former sub-space in each of the three phases of movement, the initial steady state, the intermediate position, and the final steady state. The same result was found when the changes in muscle activation were analyzed between the initial and final steady states. Changes in the dwell time between the perturbation force application and removal led to different final hand locations undershooting the initial position. The magnitude of the undershot scaled with the dwell time, while the structure of variance in the muscle activation space did not depend on the dwell time. We conclude that stability of the hand coordinate is ensured during both intentional and unintentional actions via similar mechanisms. Relative equifinality in the external space after transient perturbations may be associated with varying states in the redundant space of muscle activations. The results fit a hierarchical scheme for the control of voluntary movements with referent configurations and redundant mapping between the levels of the hierarchy. PMID:25092272

  8. Morphology, ultrastructure and contractile properties of muscles responsible for superior tentacle movements of the snail.

    PubMed

    Krajcs, Nóra; Márk, L; Elekes, K; Kiss, T

    2012-01-01

    Bending, twitching and quivering are different types of tentacle movements observed during olfactory orientation of the snail. Three recently discovered special muscles, spanning along the length of superior tentacles from the tip to the base, seem to be responsible for the execution of these movements. In this study we have investigated the ultrastructure, contractile properties and protein composition of these muscles. Our ultrastructural studies show that smooth muscle fibers are loosely embedded in a collagen matrix and they are coupled with long sarcolemma protrusions. The muscle fibers apparently lack organized SR and transverse tubular system. Instead subsarcolemmal vesicles and mitochondria have been shown to be possible Ca2+ pools for contraction. It was shown that external Ca2+ is required for contraction elicited by high (40 mM) K+ or 10-4 M ACh. Caffeine (5 mM) induced contraction in Ca2+-free solution suggesting the presence of a substantial intracellular Ca2+ pool. High-resolution electrophoretic analysis of columellar and tentacular muscles did not reveal differences in major contractile proteins, such as actin, myosin and paramyosin. Differences were observed however in several bands representing presumably regulatory enzymes. It is concluded that, the ultrastructural, biochemical and contractile properties of the string muscles support their special physiological function.

  9. Comparison of muscles activity of abled bodied and amputee subjects for around shoulder movement.

    PubMed

    Kaur, Amanpreet; Agarwal, Ravinder; Kumar, Amod

    2016-05-12

    Worldwide, about 56% of the amputees are upper limb amputees. This research deals a method with two-channel surface electromyogram (SEMG) signal recorded from around shoulder to estimate the changes in muscle activity in non-amputee and the residual limb of trans humeral amputees with different movements of arm. Identification of different muscles activity of near shoulder amputee and non-amputee persons. SEMG signal were acquired during three distinct exercises from three-selected muscles location around shoulder. The participants were asked to move their dominant arm from an assigned position to record their muscles activity recorded with change in position. Results shows the muscles activity in scalene is more than the other muscles like pectoralis and infraspinatus with the same shoulder motion. In addition, STFT (Short-Time Fourier Transform) spectrogram with window length of 256 samples at maximum of 512 frequency bins using hamming window has used to identify the signal for the maximum muscles activity with best resolution in spectrum plot. The results suggest that one can use this analysis for making a suitable device for around shoulder prosthetic users based on muscles activation of amputee persons.

  10. Automated regional analysis of B-mode ultrasound images of skeletal muscle movement.

    PubMed

    Darby, John; Hodson-Tole, Emma F; Costen, Nicholas; Loram, Ian D

    2012-01-01

    To understand the functional significance of skeletal muscle anatomy, a method of quantifying local shape changes in different tissue structures during dynamic tasks is required. Taking advantage of the good spatial and temporal resolution of B-mode ultrasound imaging, we describe a method of automatically segmenting images into fascicle and aponeurosis regions and tracking movement of features, independently, in localized portions of each tissue. Ultrasound images (25 Hz) of the medial gastrocnemius muscle were collected from eight participants during ankle joint rotation (2° and 20°), isometric contractions (1, 5, and 50 Nm), and deep knee bends. A Kanade-Lucas-Tomasi feature tracker was used to identify and track any distinctive and persistent features within the image sequences. A velocity field representation of local movement was then found and subdivided between fascicle and aponeurosis regions using segmentations from a multiresolution active shape model (ASM). Movement in each region was quantified by interpolating the effect of the fields on a set of probes. ASM segmentation results were compared with hand-labeled data, while aponeurosis and fascicle movement were compared with results from a previously documented cross-correlation approach. ASM provided good image segmentations (<1 mm average error), with fully automatic initialization possible in sequences from seven participants. Feature tracking provided similar length change results to the cross-correlation approach for small movements, while outperforming it in larger movements. The proposed method provides the potential to distinguish between active and passive changes in muscle shape and model strain distributions during different movements/conditions and quantify nonhomogeneous strain along aponeuroses.

  11. Liberty, beneficence, and involuntary confinement.

    PubMed

    Callahan, J C

    1984-08-01

    My purpose in this paper is to show that current legal criteria for paternalistic involuntary psychiatric confinement of the mentally ill are both too narrow and too broad. I do this by first developing a principle of justified paternalistic interference with adults, which I take to be acceptably protective of individual liberty, but which does not require unnecessary sacrifices of individual welfare. After offering an analysis of current legal criteria for involuntary confinement, I argue that an acceptable theory of paternalistic interference reveals that those criteria (1) exclude some cases where confinement would be morally permissible, and (2) allow paternalistic confinement of many whose detention is not morally justifiable.

  12. Muscle activity patterns during quick increase of movement amplitude in rapid elbow extensions.

    PubMed

    Takatoku, Nozomi; Fujiwara, Motoko

    2010-04-01

    In this study, we investigated a motor strategy for increasing the amplitude of movement in rapid extensions at the elbow joint. This study focused on the changes in a triphasic electromyographic (EMG) pattern, i.e., the first agonist burst (AG1), the second agonist burst (AG2) and the antagonist burst (ANT), for increasing the amplitude of movement required after the initiation of movement. Subjects performed 40 degrees (Basic task) and 80 degrees of extension (Wide task). These tasks were performed under two conditions; performing a predetermined task (SF condition) and performing a task in response to a visual stimulus immediately after movement commencement (ST condition). Kinematic parameters and EMG activity from the agonist (triceps brachii) and the antagonist (biceps brachii) muscles were recorded. As a result, the onset latency of AG1 and AG2 and the duration of AG1 were longer under the ST condition than the SF condition. No difference was observed between the SF and ST condition with respect to ANT activity. It is concluded that the motor strategy for increasing the amplitude of movement after the initiation of movement was to control the movement velocity and the timing to stop movement by the coactivation duration of AG1 and ANT and to stop the desired position accurately by AG2 activity.

  13. Eugenics and Involuntary Sterilization: 1907-2015.

    PubMed

    Reilly, Philip R

    2015-01-01

    In England during the late nineteenth century, intellectuals, especially Francis Galton, called for a variety of eugenic policies aimed at ensuring the health of the human species. In the United States, members of the Progressive movement embraced eugenic ideas, especially immigration restriction and sterilization. Indiana enacted the first eugenic sterilization law in 1907, and the US Supreme Court upheld such laws in 1927. State programs targeted institutionalized, mentally disabled women. Beginning in the late 1930s, proponents rationalized involuntary sterilization as protecting vulnerable women from unwanted pregnancy. By World War II, programs in the United States had sterilized approximately 60,000 persons. After the horrific revelations concerning Nazi eugenics (German Hereditary Health Courts approved at least 400,000 sterilization operations in less than a decade), eugenic sterilization programs in the United States declined rapidly. Simplistic eugenic thinking has faded, but coerced sterilization remains widespread, especially in China and India. In many parts of the world, involuntary sterilization is still intermittently used against minority groups.

  14. Hypnotic Involuntariness: A Social Cognitive Analysis.

    ERIC Educational Resources Information Center

    Lynn, Steven Jay; And Others

    1990-01-01

    A framework for understanding involuntary experiences which draws from social, psychological and cognitive perspectives on hypnotic responding is presented. Five reasons are suggested to reject the hypothesis that hypnotic responding is automatic and involuntary. (SLD)

  15. Hypnotic Involuntariness: A Social Cognitive Analysis.

    ERIC Educational Resources Information Center

    Lynn, Steven Jay; And Others

    1990-01-01

    A framework for understanding involuntary experiences which draws from social, psychological and cognitive perspectives on hypnotic responding is presented. Five reasons are suggested to reject the hypothesis that hypnotic responding is automatic and involuntary. (SLD)

  16. 28 CFR 549.42 - Involuntary admission.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SERVICES Administrative Safeguards for Psychiatric Treatment and Medication § 549.42 Involuntary admission. A court determination is necessary for involuntary hospitalization for psychiatric treatment. A sentenced inmate, not currently committed for psychiatric treatment, who is not able or willing...

  17. Making muscle: Morphogenetic movements and molecular mechanisms of myogenesis in Xenopus laevis.

    PubMed

    Sabillo, Armbien; Ramirez, Julio; Domingo, Carmen R

    2016-03-01

    Xenopus laevis offers unprecedented access to the intricacies of muscle development. The large, robust embryos make it ideal for manipulations at both the tissue and molecular level. In particular, this model system can be used to fate map early muscle progenitors, visualize cell behaviors associated with somitogenesis, and examine the role of signaling pathways that underlie induction, specification, and differentiation of muscle. Several characteristics that are unique to X. laevis include myogenic waves with distinct gene expression profiles and the late formation of dermomyotome and sclerotome. Furthermore, myogenesis in the metamorphosing frog is biphasic, facilitating regeneration studies. In this review, we describe the morphogenetic movements that shape the somites and discuss signaling and transcriptional regulation during muscle development and regeneration. With recent advances in gene editing tools, X. laevis remains a premier model organism for dissecting the complex mechanisms underlying the specification, cell behaviors, and formation of the musculature system.

  18. Coordinated alpha and gamma control of muscles and spindles in movement and posture

    PubMed Central

    Li, Si; Zhuang, Cheng; Hao, Manzhao; He, Xin; Marquez, Juan C.; Niu, Chuanxin M.; Lan, Ning

    2015-01-01

    Mounting evidence suggests that both α and γ motoneurons are active during movement and posture, but how does the central motor system coordinate the α-γ controls in these tasks remains sketchy due to lack of in vivo data. Here a computational model of α-γ control of muscles and spindles was used to investigate α-γ integration and coordination for movement and posture. The model comprised physiologically realistic spinal circuitry, muscles, proprioceptors, and skeletal biomechanics. In the model, we divided the cortical descending commands into static and dynamic sets, where static commands (αs and γs) were for posture maintenance and dynamic commands (αd and γd) were responsible for movement. We matched our model to human reaching movement data by straightforward adjustments of descending commands derived from either minimal-jerk trajectories or human EMGs. The matched movement showed smooth reach-to-hold trajectories qualitatively close to human behaviors, and the reproduced EMGs showed the classic tri-phasic patterns. In particular, the function of γd was to gate the αd command at the propriospinal neurons (PN) such that antagonistic muscles can accelerate or decelerate the limb with proper timing. Independent control of joint position and stiffness could be achieved by adjusting static commands. Deefferentation in the model indicated that accurate static commands of αs and γs are essential to achieve stable terminal posture precisely, and that the γd command is as important as the αd command in controlling antagonistic muscles for desired movements. Deafferentation in the model showed that losing proprioceptive afferents mainly affected the terminal position of movement, similar to the abnormal behaviors observed in human and animals. Our results illustrated that tuning the simple forms of α-γ commands can reproduce a range of human reach-to-hold movements, and it is necessary to coordinate the set of α-γ descending commands for accurate

  19. Muscle Strength Imbalance in the Hip Joint Caused by Fast Movements

    NASA Astrophysics Data System (ADS)

    Pontaga, I.

    2003-07-01

    Eleven male sportsmen at the age of 24.3 ± 4.5 were examined. Their hip joint flexors and extensors were tested by an "REV-9000" Technogym dynamometer system during isokinetic movements at angular velocities of 100 (low) and 200 (high) °/s. The range of hip joint movements was from 30 (in flexion) to 130° (in extension). Torque values and their ratios for hip flexors and extensors at different angular positions were obtained and compared. It is shown that, at high speeds, the flexion movement significantly raises ( p < 0.001) the torque ratios of flexors and extensors in flexion positions of the hip (50 and 60°). These ratios approximately twofold exceed their values at moderate velocities. The weakness of hip joint extensors in extreme flexion positions of the hip may cause injury of this group of muscles at fast movements.

  20. Shoulder muscle activity in Parkinson's disease during multijoint arm movements across a range of speeds.

    PubMed

    Farley, Becky G; Sherman, Scott; Koshland, Gail F

    2004-01-01

    Bradykinesia is one of the primary symptoms of Parkinson disease and leads to significant functional limitations for patients. Single joint movement studies, that have investigated the mechanism of bradykinesia, suggest that several features of muscle activity are disrupted, including modulation of burst amplitude and duration, and the number of bursts. It has been proposed that it is the blending of these different burst deficits that collectively defines bradykinesia. This study adds two new approaches to the study of bradykinesia. First, we examined the features of shoulder muscle activities during multijoint arm movement in bradykinetic and control subjects, such that previously reported single joint hypotheses could be tested for generalized arm movement. Second, we directly manipulated speed while keeping distance constant for a large range of speeds. In this manner, we could compare individual trials of muscle activity between controls and subjects with Parkinson's disease (PD) for movements matched for both speed and movement duration. Our results showed that while a multiple burst pattern of shoulder muscles was a common strategy for all subjects (young, elderly controls and PD), subjects with PD showed several burst abnormalities, including deficits in initial agonist burst amplitude and duration at both fast and slow speeds. Subjects with PD also (1) failed to produce a one-burst pattern at fast speeds and, instead, produced a predominance of multiple burst patterns and (2) showed a relationship between the number of burst deficits and the severity of disease. These results extend the findings of single joint studies to multi-joint and similarly indicate that a combination of burst modulation abnormalities correlate with bradykinesia and disease severity.

  1. Convergence and extension movements mediate the specification and fate maintenance of zebrafish slow muscle precursors.

    PubMed

    Yin, Chunyue; Solnica-Krezel, Lilianna

    2007-04-01

    During vertebrate gastrulation, concurrent inductive events and cell movements fashion the body plan. Convergence and extension (C&E) gastrulation movements narrow the vertebrate embryonic body mediolaterally while elongating it rostrocaudally. Segmented somites are shaped and positioned by C&E alongside the notochord and differentiate into skeleton, fast, and slow muscles during somitogenesis. In zebrafish, simultaneous inactivation of non-canonical Wnt signaling components Knypek and Trilobite strongly impairs C&E gastrulation movements. Here we show that knypek;trilobite double mutants exhibit a severe deficit in slow muscles and their precursor, adaxial cells, revealing essential roles of C&E movements in adaxial cell development. Adaxial cells become distinguishable in the presomitic mesoderm during late gastrulation by their expression of myogenic factors and axial-adjacent position. Using cell tracing analyses and genetic manipulations, we demonstrate that C&E movements regulate the number of prospective adaxial cells specified during gastrulation by determining the size of the interface between the inductive axial and target presomitic tissues. During segmentation, when the range of Hedgehog signaling from the axial tissue declines, tight apposition of prospective adaxial cells to the notochord, which is achieved by convergence movements, is necessary for their continuous Hedgehog reception and fate maintenance. We provide direct evidence to show that the deficiency of adaxial cells in knypek;trilobite double mutants is due to impaired C&E movements, rather than an alteration in Hedgehog signal and its reception, or a cell-autonomous requirement for Knypek and Trilobite in adaxial cell development. Our results underscore the significance of precise coordination between cell movements and inductive tissue interactions during cell fate specification.

  2. Control of position and movement is simplified by combined muscle spindle and Golgi tendon organ feedback.

    PubMed

    Kistemaker, Dinant A; Van Soest, Arthur J Knoek; Wong, Jeremy D; Kurtzer, Isaac; Gribble, Paul L

    2013-02-01

    Whereas muscle spindles play a prominent role in current theories of human motor control, Golgi tendon organs (GTO) and their associated tendons are often neglected. This is surprising since there is ample evidence that both tendons and GTOs contribute importantly to neuromusculoskeletal dynamics. Using detailed musculoskeletal models, we provide evidence that simple feedback using muscle spindles alone results in very poor control of joint position and movement since muscle spindles cannot sense changes in tendon length that occur with changes in muscle force. We propose that a combination of spindle and GTO afferents can provide an estimate of muscle-tendon complex length, which can be effectively used for low-level feedback during both postural and movement tasks. The feasibility of the proposed scheme was tested using detailed musculoskeletal models of the human arm. Responses to transient and static perturbations were simulated using a 1-degree-of-freedom (DOF) model of the arm and showed that the combined feedback enabled the system to respond faster, reach steady state faster, and achieve smaller static position errors. Finally, we incorporated the proposed scheme in an optimally controlled 2-DOF model of the arm for fast point-to-point shoulder and elbow movements. Simulations showed that the proposed feedback could be easily incorporated in the optimal control framework without complicating the computation of the optimal control solution, yet greatly enhancing the system's response to perturbations. The theoretical analyses in this study might furthermore provide insight about the strong physiological couplings found between muscle spindle and GTO afferents in the human nervous system.

  3. Control of position and movement is simplified by combined muscle spindle and Golgi tendon organ feedback

    PubMed Central

    Van Soest, Arthur J. Knoek; Wong, Jeremy D.; Kurtzer, Isaac; Gribble, Paul L.

    2013-01-01

    Whereas muscle spindles play a prominent role in current theories of human motor control, Golgi tendon organs (GTO) and their associated tendons are often neglected. This is surprising since there is ample evidence that both tendons and GTOs contribute importantly to neuromusculoskeletal dynamics. Using detailed musculoskeletal models, we provide evidence that simple feedback using muscle spindles alone results in very poor control of joint position and movement since muscle spindles cannot sense changes in tendon length that occur with changes in muscle force. We propose that a combination of spindle and GTO afferents can provide an estimate of muscle-tendon complex length, which can be effectively used for low-level feedback during both postural and movement tasks. The feasibility of the proposed scheme was tested using detailed musculoskeletal models of the human arm. Responses to transient and static perturbations were simulated using a 1-degree-of-freedom (DOF) model of the arm and showed that the combined feedback enabled the system to respond faster, reach steady state faster, and achieve smaller static position errors. Finally, we incorporated the proposed scheme in an optimally controlled 2-DOF model of the arm for fast point-to-point shoulder and elbow movements. Simulations showed that the proposed feedback could be easily incorporated in the optimal control framework without complicating the computation of the optimal control solution, yet greatly enhancing the system's response to perturbations. The theoretical analyses in this study might furthermore provide insight about the strong physiological couplings found between muscle spindle and GTO afferents in the human nervous system. PMID:23100138

  4. Fish Swimming: Patternsin the Mechanical Energy Generation, Transmission and Dissipation from Muscle Activation to Body Movement

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Yu, Y. L.; Tong, B. G.

    2011-09-01

    The power consumption of the undulatory fish swimming is produced by active muscles. The mechanical energy generated by stimulated muscles is dissipated partly by the passive tissues of fish while it is being transmitted to the fluid medium. Furthermore, the effective energy, propelling fish movement, is a part of that delivered by the fish body. The process depends on the interactions of the active muscles, the passive tissues, and the water surrounding the fish body. In the previous works, the body-fluid interactions have been investigated widely, but it is rarely considered how the mechanical energy generates, transmits and dissipates in fish swimming. This paper addresses the regular patterns of energy transfer process from muscle activation to body movement for a cruising lamprey (LAMPREY), a kind of anguilliform swimmer. It is necessary to propose a global modelling of the kinematic chain, which is composed of active muscle force-moment model, fish-body dynamic model and hydrodynamic model in order. The present results show that there are traveling energy waves along the fish body from anterior to posterior, accompanied with energy storing and dissipating due to the viscoelastic property of internal tissues. This study is a preliminary research on the framework of kinematic chain coordination performance in fish swimming.

  5. The Mechanisms of Involuntary Attention

    ERIC Educational Resources Information Center

    Prinzmetal, William; Ha, Ruby; Khani, Aniss

    2010-01-01

    We tested 3 mechanisms of involuntary attention: (1) a perceptual enhancement mechanism, (2) a response-decision mechanism, and (3) a serial-search mechanism. Experiment 1 used a response deadline technique to compare the perceptual enhancement and the decision mechanisms and found evidence consistent with the decision mechanism. Experiment 2 used…

  6. Involuntary Smoking and Children's Health.

    ERIC Educational Resources Information Center

    Samet, Jonathan M.; And Others

    1994-01-01

    Reviews and analyzes findings indicating that exposure to involuntary smoking is detrimental to the health of children, discusses measures taken to decrease their exposure, and explores additional interventions that might be considered. Lessons learned from reductions in active smoking in public places are emphasized, and suggestions are made…

  7. Cocontraction of Pairs of Muscles around Joints May Improve an Accuracy of a Reaching Movement: a Numerical Simulation Study

    NASA Astrophysics Data System (ADS)

    Ueyama, Yuki; Miyashita, Eizo

    2011-06-01

    We have pair muscle groups on a joint; agonist and antagonist muscles. Simultaneous activation of agonist and antagonist muscles around a joint, which is called cocontraction, is suggested to take a role of increasing the joint stiffness in order to decelerate hand speed and improve movement accuracy. However, it has not been clear how cocontraction and the joint stiffness are varied during movements. In this study, muscle activation and the joint stiffness in reaching movements were studied under several requirements of end-point accuracy using a 2-joint 6-muscle model and an approximately optimal control. The time-varying cocontraction and the joint stiffness were showed by the numerically simulation study. It indicated that the strength of cocontraction and the joint stiffness increased synchronously as the required accuracy level increased. We conclude that cocontraction may get the joint stiffness increased to achieve higher requirement of the movement accuracy.

  8. The proprioceptive senses: their roles in signaling body shape, body position and movement, and muscle force.

    PubMed

    Proske, Uwe; Gandevia, Simon C

    2012-10-01

    This is a review of the proprioceptive senses generated as a result of our own actions. They include the senses of position and movement of our limbs and trunk, the sense of effort, the sense of force, and the sense of heaviness. Receptors involved in proprioception are located in skin, muscles, and joints. Information about limb position and movement is not generated by individual receptors, but by populations of afferents. Afferent signals generated during a movement are processed to code for endpoint position of a limb. The afferent input is referred to a central body map to determine the location of the limbs in space. Experimental phantom limbs, produced by blocking peripheral nerves, have shown that motor areas in the brain are able to generate conscious sensations of limb displacement and movement in the absence of any sensory input. In the normal limb tendon organs and possibly also muscle spindles contribute to the senses of force and heaviness. Exercise can disturb proprioception, and this has implications for musculoskeletal injuries. Proprioceptive senses, particularly of limb position and movement, deteriorate with age and are associated with an increased risk of falls in the elderly. The more recent information available on proprioception has given a better understanding of the mechanisms underlying these senses as well as providing new insight into a range of clinical conditions.

  9. Quantifying forearm muscle activity during wrist and finger movements by means of multi-channel electromyography.

    PubMed

    Gazzoni, Marco; Celadon, Nicolò; Mastrapasqua, Davide; Paleari, Marco; Margaria, Valentina; Ariano, Paolo

    2014-01-01

    The study of hand and finger movement is an important topic with applications in prosthetics, rehabilitation, and ergonomics. Surface electromyography (sEMG) is the gold standard for the analysis of muscle activation. Previous studies investigated the optimal electrode number and positioning on the forearm to obtain information representative of muscle activation and robust to movements. However, the sEMG spatial distribution on the forearm during hand and finger movements and its changes due to different hand positions has never been quantified. The aim of this work is to quantify 1) the spatial localization of surface EMG activity of distinct forearm muscles during dynamic free movements of wrist and single fingers and 2) the effect of hand position on sEMG activity distribution. The subjects performed cyclic dynamic tasks involving the wrist and the fingers. The wrist tasks and the hand opening/closing task were performed with the hand in prone and neutral positions. A sensorized glove was used for kinematics recording. sEMG signals were acquired from the forearm muscles using a grid of 112 electrodes integrated into a stretchable textile sleeve. The areas of sEMG activity have been identified by a segmentation technique after a data dimensionality reduction step based on Non Negative Matrix Factorization applied to the EMG envelopes. The results show that 1) it is possible to identify distinct areas of sEMG activity on the forearm for different fingers; 2) hand position influences sEMG activity level and spatial distribution. This work gives new quantitative information about sEMG activity distribution on the forearm in healthy subjects and provides a basis for future works on the identification of optimal electrode configuration for sEMG based control of prostheses, exoskeletons, or orthoses. An example of use of this information for the optimization of the detection system for the estimation of joint kinematics from sEMG is reported.

  10. Quantifying Forearm Muscle Activity during Wrist and Finger Movements by Means of Multi-Channel Electromyography

    PubMed Central

    Gazzoni, Marco; Celadon, Nicolò; Mastrapasqua, Davide; Paleari, Marco; Margaria, Valentina; Ariano, Paolo

    2014-01-01

    The study of hand and finger movement is an important topic with applications in prosthetics, rehabilitation, and ergonomics. Surface electromyography (sEMG) is the gold standard for the analysis of muscle activation. Previous studies investigated the optimal electrode number and positioning on the forearm to obtain information representative of muscle activation and robust to movements. However, the sEMG spatial distribution on the forearm during hand and finger movements and its changes due to different hand positions has never been quantified. The aim of this work is to quantify 1) the spatial localization of surface EMG activity of distinct forearm muscles during dynamic free movements of wrist and single fingers and 2) the effect of hand position on sEMG activity distribution. The subjects performed cyclic dynamic tasks involving the wrist and the fingers. The wrist tasks and the hand opening/closing task were performed with the hand in prone and neutral positions. A sensorized glove was used for kinematics recording. sEMG signals were acquired from the forearm muscles using a grid of 112 electrodes integrated into a stretchable textile sleeve. The areas of sEMG activity have been identified by a segmentation technique after a data dimensionality reduction step based on Non Negative Matrix Factorization applied to the EMG envelopes. The results show that 1) it is possible to identify distinct areas of sEMG activity on the forearm for different fingers; 2) hand position influences sEMG activity level and spatial distribution. This work gives new quantitative information about sEMG activity distribution on the forearm in healthy subjects and provides a basis for future works on the identification of optimal electrode configuration for sEMG based control of prostheses, exoskeletons, or orthoses. An example of use of this information for the optimization of the detection system for the estimation of joint kinematics from sEMG is reported. PMID:25289669

  11. Effect of cooling during inter-exercise periods on subsequent intramuscular water movement and muscle performance.

    PubMed

    Yanagisawa, O; Otsuka, S; Fukubayashi, T

    2014-02-01

    To evaluate the effects of cooling between exercise sessions on intramuscular water movement and muscle performance, the lower extremities of nine untrained men were assigned to either a cooling protocol (20-min water immersion, 15 °C) or a noncooling protocol. Each subject performed two exercise sessions involving maximal concentric knee extension and flexion (three repetitions, 60°/s; followed by 50 repetitions, 180°/s). The peak torque at 60°/s and total work, mean power, and decrease rate of torque value at 180°/s were evaluated. Axial magnetic resonance diffusion-weighted images of the mid-thigh were obtained before and after each exercise session. Apparent diffusion coefficient (ADC) values for the quadriceps and hamstrings were calculated for evaluating intramuscular water movement. Both groups exhibited significantly increased ADC values for the quadriceps and hamstrings after each exercise session. These ADC values returned to the pre-exercise level after water immersion. No significant difference was observed in muscle performance from first exercise session to the next in either group, except for increased total work and mean power in knee flexion in the cooled group. Cooling intervention between exercise sessions decreased exercise-induced elevation of intramuscular water movement and had some beneficial effects on muscle endurance of knee flexors, but not knee extensors. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Low-load Slow Movement Squat Training Increases Muscle Size and Strength but Not Power.

    PubMed

    Usui, S; Maeo, S; Tayashiki, K; Nakatani, M; Kanehisa, H

    2016-04-01

    We tested a hypothesis that low-load squat training with slow movement and tonic force generation (LST) would increase muscle size and strength but not necessarily power. Healthy young men were assigned to LST [50% one-repetition maximum (1-RM) load, 3 s for lowering/lifting without pause: n=9] or low-load normal speed (LN: 50% 1-RM load, 1 s for lowering/lifting with 1-s pause; n=7) groups. Both groups underwent an 8-week squat training program (10 repetitions/set, 3 sets/day, and 3 days/week) using the assigned methods. Before and after the intervention, quadriceps femoris muscle thickness, maximal torque during isometric hip extension and knee extension, 1-RM squat, lifting power from squatting position and rate of electromyography rise (RER) in knee extensors during the task, leg extension power and vertical jump height were measured. After the intervention, the LN group showed no changes in all the variables. The LST group significantly (P<0.05) increased muscle thickness (6-10%), isometric hip extension torque (18%) and 1-RM squat (10%), but not isometric knee extension torque, lifting power and RER, leg extension power and vertical jump height. These results suggest that LST can increase muscle size and task-related strength, but has little effect on power production during dynamic explosive movements. © Georg Thieme Verlag KG Stuttgart · New York.

  13. The patellar reflex: does activity of quadriceps femoris muscles reflect leg movement?

    PubMed

    Dafkin, Chloe; Green, Andrew; Kerr, Samantha; McKinon, Warrick

    2012-07-01

    The assessment of spinal reflexes has traditionally been performed by clinicians with minimal need for recording equipment, where doctors rely on their training and may use established subjective reflex rating scales. With advances in technology, it is now possible to assess reflexes objectively. This study compared two objective methods of assessing patellar reflex magnitude, duration, and latency, namely electromyography (EMG) of the quadriceps muscles and kinematic assessment of the leg movement around the knee joint. Reflexes of 24 healthy participants were assessed and seven variables were found to describe each reflex. These were the change in knee angle, the velocity of the reflex, the time to maximum knee angle, the biomechanical movement latency, the EMG maximum amplitude, the negative peak duration, and the EMG latency. Spearman's rank correlation tests were run in order to compare all of the variables. The results showed that there were positive correlations between EMG maximum amplitude and the change in knee angle (R(2) = 0.75; P < 0.0001) as well as the EMG maximum amplitude and the velocity of the reflex (R(2) = 0.30; P = 0.0058). There was also a negative correlation between EMG maximum amplitude and the biomechanical movement latency (R(2) = 0.35; P = 0.0024). The results show that there is a relationship between muscle activity and the actual visual movement of the leg assessed using kinematics. This relationship is closest between kinematic measurements and EMG measures of reflex amplitude.

  14. Types of muscle tissue (image)

    MedlinePlus

    The 3 types of muscle tissue are cardiac, smooth, and skeletal. Cardiac muscle cells are located in ... heart, appear striated, and are under involuntary control. Smooth muscle fibers are located in walls of hollow ...

  15. Legal briefing: coerced treatment and involuntary confinement for contagious disease.

    PubMed

    Pope, Thaddeus Mason; Bughman, Heather Michelle

    2015-01-01

    This issue's "Legal Briefing" column covers recent legal developments involving coerced treatment and involuntary confinement for contagious disease. Recent high profile court cases involving measles, tuberculosis, human immunodeficiency virus, and especially Ebola, have thrust this topic back into the bioethics and public spotlights. This has reignited debates over how best to balance individual liberty and public health. For example, the Presidential Commission for the Study of Bioethical Issues has officially requested public comments, held open hearings, and published a 90-page report on "ethical considerations and implications" raised by "U.S. public policies that restrict association or movement (such as quarantine)." Broadly related articles have been published in previous issues of The Journal of Clinical Ethics. We categorize recent legal developments on coerced treatment and involuntary confinement into the following six categories: 1. Most Public Health Confinement Is Voluntary 2. Legal Requirements for Involuntary Confinement 3. New State Laws Authorizing Involuntary Confinement 4. Quarantine Must Be as Least Restrictive as Necessary 5. Isolation Is Justified Only as a Last Resort 6. Coerced Treatment after Persistent Noncompliance. Copyright 2015 The Journal of Clinical Ethics. All rights reserved.

  16. Model-based prediction of fusimotor activity and its effect on muscle spindle activity during voluntary wrist movements.

    PubMed

    Grandjean, Bernard; Maier, Marc A

    2014-08-01

    Muscle spindles provide critical information about movement position and velocity. They have been shown to act as stretch receptors in passive muscle, however, during active movements their behavior is less clear. In particular, spindle responses have been shown to be out-of-phase or phase advanced with respect to their expected muscle length-sensitivity. Whether this apparent discrepancy of spindle responses between passive and active movements is due to fusimotor (γ-drive) remains unresolved, since the activity of fusimotor neurons during voluntary non-locomotor movements are largely unknown. We developed a computational model to predict fusimotor activity and to investigate whether fusimotor activity could explain the empirically observed phase advance of spindle responses. The model links a biomechanical wrist model to length- and γ-drive-dependent transfer functions of type Ia and type II muscle spindle activity. Our simulations of two wrist-movement tasks suggest that (i) experimentally observed type Ia and type II activity profiles can to a large part be explained by appropriate, i.e. strongly modulated and task-dependent, γ-drive. That (ii) the empirically observed phase advance of type Ia or of type II profiles during active movement can be similarly explained by appropriate γ-drive. In summary, the simulation predicts that a highly task-modulated activation of the γ-system is instrumental in producing a large part of the empirically observed muscle spindle activity for voluntary wrist movements.

  17. Muscle coordination limits efficiency and power output of human limb movement under a wide range of mechanical demands

    PubMed Central

    Wakeling, James M.

    2015-01-01

    This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120–140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. PMID:26445873

  18. Muscle coordination limits efficiency and power output of human limb movement under a wide range of mechanical demands.

    PubMed

    Blake, Ollie M; Wakeling, James M

    2015-12-01

    This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120-140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. Copyright © 2015 the American Physiological Society.

  19. Coordination of jaw and extrinsic tongue muscle activity during rhythmic jaw movements in anesthetized rabbits.

    PubMed

    Ariyasinghe, Sajjiv; Inoue, Makoto; Yamamura, Kensuke; Harasawa, Yohji; Kurose, Masayuki; Yamada, Yoshiaki

    2004-08-06

    To clarify the jaw-closer and tongue-retractor muscle activity patterns during mastication, electromyographic activity of the styloglossus (SG) as a tongue-retractor and masseter (Mass) as a jaw-closer muscles as well as jaw-movement trajectories were recorded during cortically evoked rhythmic jaw movements (CRJMs) in anesthetized rabbits. The SG and Mass muscles were mainly active during the jaw-closing (Cl) phase. The SG activity was composed of two bursts in one masticatory cycle; one had its peak during the jaw-opening (Op) phase (SG1 burst) and the other during the Cl phase (SG2 burst). The Mass activity during the Cl phase was dominant on the working side (opposite to the stimulating side) while the SG1 and SG2 bursts were not different between the sides. When the wooden stick was inserted between the molar teeth on the working side during CRJMs, the facilitatory effects on the SG1 and SG2 bursts on both sides were noted as well as those on the Mass bursts, but the effects on the SG1 burst seemed to be weak as compared with those on the Mass and SG2 bursts. The difference in the burst timing between the sides was noted only in the SG1 burst. When the trigeminal nerves were blocked, the peak and area of the SG and Mass burst decreased during CRJMs, and the facilitatory effects of the wooden stick application on the muscles were not noted. The results suggest that the jaw and tongue muscle activities may be adjusted to chew the food and make the food bolus.

  20. Analysis of masseter muscle oxygenation and mandibular movement during experimental gum chewing with different hardness.

    PubMed

    Yoshida, Tomoharu; Ishikawa, Hiroyuki; Yoshida, Norio; Hisanaga, Yutaka

    2009-01-01

    The purpose of this study was to analyze masseter muscle oxygenation changes and mandibular movements in the experimental chewing of gums with different hardness. Subjects for this experiment comprised 23 male volunteers with normal occlusion. Mean age (SD) was 28.3 (2.2) years. Three kinds of gum with mean fracture stresses of 3.52 x 10(4) N/m(2) (Gum 1), 5.35 x 10(4) N/m(2) (Gum 2), and 14.0 x 10(4) N/m(2) (Gum 3) were used. The subjects were instructed to chew gum for 80 s (100 strokes) on the voluntary chewing side at a pace of 1.25 strokes/s. Oxygen saturation in the masseter muscle and mandibular movement during gum chewing were recorded simultaneously using near-infrared spectroscopy tissue oximetry and mandibular kinesiography. For Gum 1, no subjects showed any significant changes in oxygen saturation during gum chewing. For Gum 2, 10 subjects showed no significant changes, whereas the other 13 showed significant decreases in oxygen saturation. For Gum 3, significant decreases were seen in all subjects. Chewing motions were larger and velocity was higher in gum chewing with decreases in masseter muscle oxygen saturation compared to chewing showing no significant changes. The results suggest that the harder texture of gum enlarges chewing motion and increases chewing velocity, with an increase in the contribution of anaerobic metabolism to energy yield in masseter muscle. Differences in the responses to gum hardness may indicate individual differences in muscle fatigue tendencies when chewing harder foods.

  1. A modeling investigation of vowel-to-vowel movement planning in acoustic and muscle spaces

    NASA Astrophysics Data System (ADS)

    Zandipour, Majid

    The primary objective of this research was to explore the coordinate space in which speech movements are planned. A two dimensional biomechanical model of the vocal tract (tongue, lips, jaw, and pharynx) was constructed based on anatomical and physiological data from a subject. The model transforms neural command signals into the actions of muscles. The tongue was modeled by a 221-node finite element mesh. Each of the eight tongue muscles defined within the mesh was controlled by a virtual muscle model. The other vocal-tract components were modeled as simple 2nd-order systems. The model's geometry was adapted to a speaker, using MRI scans of the speaker's vocal tract. The vocal tract model, combined with an adaptive controller that consisted of a forward model (mapping 12-dimensional motor commands to a 64-dimensional acoustic spectrum) and an inverse model (mapping acoustic trajectories to motor command trajectories), was used to simulate and explore the implications of two planning hypotheses: planning in motor space vs. acoustic space. The acoustic, kinematic, and muscle activation (EMG) patterns of vowel-to-vowel sequences generated by the model were compared to data from the speaker whose acoustic, kinematic and EMG were also recorded. The simulation results showed that: (a) modulations of the motor commands effectively accounted for the effects of speaking rate on EMG, kinematic, and acoustic outputs; (b) the movement and acoustic trajectories were influenced by vocal tract biomechanics; and (c) both planning schemes produced similar articulatory movement, EMG, muscle length, force, and acoustic trajectories, which were also comparable to the subject's data under normal speaking conditions. In addition, the effects of a bite-block on measured EMG, kinematics and formants were simulated by the model. Acoustic planning produced successful simulations but motor planning did not. The simulation results suggest that with somatosensory feedback but no auditory

  2. Muscle and eye movement artifact removal prior to EEG source localization.

    PubMed

    Hallez, Hans; Vergult, Anneleen; Phlypo, Ronald; Van Hese, Peter; De Clercq, Wim; D'Asseler, Yves; Van de Walle, Rik; Vanrumste, Bart; Van Paesschen, Wim; Van Huffel, Sabine; Lemahieu, Ignace

    2006-01-01

    Muscle and eye movement artifacts are very prominent in the ictal EEG of patients suffering from epilepsy, thus making the dipole localization of ictal activity very unreliable. Recently, two techniques (BSS-CCA and pSVD) were developed to remove those artifacts. The purpose of this study is to assess whether the removal of muscle and eye movement artifacts improves the EEG dipole source localization. We used a total of 8 EEG fragments, each from another patient, first unfiltered, then filtered by the BSS-CCA and pSVD. In both the filtered and unfiltered EEG fragments we estimated multiple dipoles using RAP-MUSIC. The resulting dipoles were subjected to a K-means clustering algorithm, to extract the most prominent cluster. We found that the removal of muscle and eye artifact results to tighter and more clear dipole clusters. Furthermore, we found that localization of the filtered EEG corresponded with the localization derived from the ictal SPECT in 7 of the 8 patients. Therefore, we can conclude that the BSS-CCA and pSVD improve localization of ictal activity, thus making the localization more reliable for the presurgical evaluation of the patient.

  3. Proprioceptive control of wrist movements in Parkinson's disease. Reduced muscle vibration-induced errors.

    PubMed

    Rickards, C; Cody, F W

    1997-06-01

    The effects upon the trajectories of practised slow (approximately 9 degrees/s) voluntary wrist-extension movements of applying vibration to the tendon of an antagonist muscle (flexor carpi radialis) during the course of the movement have been studied in patients with idiopathic Parkinson's disease and age-matched healthy individuals. In both patient and control groups, flexor vibration elicited undershooting of wrist-extension movements. Wrist extensor and flexor surface EMG recordings indicated that, in patients and controls, such undershooting resulted principally from sustained reductions in extensor (prime mover) activity. Small vibration reflexes were commonly elicited in the wrist flexors which, in both Parkinson's disease and healthy subjects, were usually otherwise virtually quiescent during these slow extension movements. The amplitudes of such vibration reflexes did not differ systematically between patient and control groups and appeared inadequate to have exerted an appreciable braking action upon the extension trajectories. However, the extent of vibration-induced undershooting was, on average, significantly less in the Parkinson's disease group. In a subgroup of patients with asymmetrical parkinsonism the effects of antagonist vibration upon wrist movements of the more and less affected limb were compared. The degree of vibration-induced undershooting was significantly smaller on the more affected side. This finding suggests that disturbed proprioceptive guidance of voluntary movements in Parkinson's disease is related to the severity of clinical motor deficits. A small number Parkinson's disease patients were studied 'ON' and 'OFF' their routine anti-parkinsonian medication. A non-significant tendency was found for vibration-induced errors to be less marked in the 'OFF' state. In a separate series of experiments, under isometric conditions, vibration-induced EMG changes were recorded whilst subjects attempted to maintain a steady (15% maximum

  4. Postsynaptic Inhibition of Hypoglossal Motoneurons Produces Atonia of the Genioglossal Muscle During Rapid Eye Movement Sleep

    PubMed Central

    Fung, Simon J.; Chase, Michael H.

    2015-01-01

    Study Objectives: Hypoglossal motoneurons were recorded intracellularly to determine whether postsynaptic inhibition or disfacilitation was responsible for atonia of the lingual muscles during rapid eye movement (REM) sleep. Design: Intracellular records were obtained of the action potentials and subthreshold membrane potential activity of antidromically identified hypoglossal motoneurons in cats during wakefulness, nonrapid eye movement (NREM) sleep, and REM sleep. A cuff electrode was placed around the hypoglossal nerve to antidromically activate hypoglossal motoneurons. The state-dependent changes in membrane potential, spontaneous discharge, postsynaptic potentials, and rheobase of hypoglossal motoneurons were determined. Analyses and Results: During quiet wakefulness and NREM sleep, hypoglossal motoneurons exhibited spontaneous repetitive discharge. In the transition from NREM sleep to REM sleep, repetitive discharge ceased and the membrane potential began to hyperpolarize; maximal hyperpolarization (10.5 mV) persisted throughout REM sleep. During REM sleep there was a significant increase in rheobase, which was accompanied by barrages of large-amplitude inhibitory postsynaptic potentials (IPSPs), which were reversed following the intracellular injection of chloride ions. The latter result indicates that they were mediated by glycine; IPSPs were not present during wakefulness or NREM sleep. Conclusions: We conclude that hypoglossal motoneurons are postsynaptically inhibited during naturally occurring REM sleep; no evidence of disfacilitation was observed. The data also indicate that glycine receptor-mediated postsynaptic inhibition of hypoglossal motoneurons is crucial in promoting atonia of the lingual muscles during REM sleep. Citation: Fung SJ, Chase MH. Postsynaptic inhibition of hypoglossal motoneurons produces atonia of the genioglossal muscle during rapid eye movement sleep. SLEEP 2015;38(1):139–146. PMID:25325470

  5. 29 CFR 785.28 - Involuntary attendance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS HOURS WORKED Application of Principles Lectures, Meetings and Training Programs § 785.28 Involuntary attendance. Attendance is not voluntary,...

  6. 29 CFR 785.28 - Involuntary attendance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS HOURS WORKED Application of Principles Lectures, Meetings and Training Programs § 785.28 Involuntary attendance. Attendance is not voluntary,...

  7. 29 CFR 785.28 - Involuntary attendance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS HOURS WORKED Application of Principles Lectures, Meetings and Training Programs § 785.28 Involuntary attendance. Attendance is not voluntary,...

  8. 29 CFR 785.28 - Involuntary attendance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS HOURS WORKED Application of Principles Lectures, Meetings and Training Programs § 785.28 Involuntary attendance. Attendance is not voluntary,...

  9. 29 CFR 785.28 - Involuntary attendance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS HOURS WORKED Application of Principles Lectures, Meetings and Training Programs § 785.28 Involuntary attendance. Attendance is not voluntary,...

  10. Effects of isometric hip movements on electromyographic activities of the trunk muscles during plank exercises

    PubMed Central

    Kang, Min-Hyeok; Kim, Soo-Yong; Kang, Myoung-Joo; Yoon, So-Hee; Oh, Jae-Seop

    2016-01-01

    [Purpose] The purpose of this study was to investigate the effect of isometric hip adduction and abduction on trunk muscle activity during plank exercises. [Subjects and Methods] Nineteen healthy male subjects were recruited for this study. All subjects performed the traditional plank exercise (TP), plank exercise with isometric hip adduction (PHAD), and plank exercise with isometric hip abduction (PHAB) by using an elastic band. Electromyographic (EMG) activities of the internal oblique (IO) and external oblique (EO) were measured during the 3 plank exercises by using an Electromyography system. [Results] Internal oblique and external oblique muscle activities were significantly greater during plank exercise with isometric hip adduction and plank exercise with isometric hip abduction than during traditional plank exercise. Internal oblique and external oblique muscle activities did not differ between the plank exercise with isometric hip adduction and plank exercise with isometric hip abduction conditions. [Conclusion] These findings demonstrate that loaded isometric hip movements may be a useful strategy to increase trunk muscle activity during plank exercises. PMID:27630435

  11. On the relevance of structure preservation to simulations of muscle actuated movements.

    PubMed

    Maas, Ramona; Siebert, Tobias; Leyendecker, Sigrid

    2012-03-01

    In this work, we implement a typical nonlinear Hill-type muscle model in a structure-preserving simulation framework and investigate the differences to standard simulations of muscle-actuated movements with MATLAB/Simulink. The latter is a common tool to solve dynamical problems, in particular, in biomechanic investigations. Despite the simplicity of the examples used for comparison, it becomes obvious that the MATLAB/Simulink integrators artificially loose or gain energy and angular momentum during dynamic simulations. The relative energy error of the MATLAB/Simulink integrators related to a very low actual muscle work can naturally reach large values, even higher than 100%. But also during periods with large muscle work, the relative energy error reaches up to 2%. Even in simulations with very small time steps, energy and angular momentum errors are still present using MATLAB/Simulink and can (at least partially) be responsible for phase errors in long-term simulations. This typical behaviour of commercial integrators is known to increase for more complex models or for computations with larger time steps, whose use is crucial for efficiency, especially in the context of optimal control simulations. In contrast to that, time-stepping schemes being derived from a discrete variational principle yield discrete analogues of the Euler-Lagrange equations and Noethers theorem. This ensures that the structure of the system is preserved, i.e. the simulation results are symplectic and momentum consistent and exhibit a good energy behaviour (no drift).

  12. Effects of isometric hip movements on electromyographic activities of the trunk muscles during plank exercises.

    PubMed

    Kang, Min-Hyeok; Kim, Soo-Yong; Kang, Myoung-Joo; Yoon, So-Hee; Oh, Jae-Seop

    2016-08-01

    [Purpose] The purpose of this study was to investigate the effect of isometric hip adduction and abduction on trunk muscle activity during plank exercises. [Subjects and Methods] Nineteen healthy male subjects were recruited for this study. All subjects performed the traditional plank exercise (TP), plank exercise with isometric hip adduction (PHAD), and plank exercise with isometric hip abduction (PHAB) by using an elastic band. Electromyographic (EMG) activities of the internal oblique (IO) and external oblique (EO) were measured during the 3 plank exercises by using an Electromyography system. [Results] Internal oblique and external oblique muscle activities were significantly greater during plank exercise with isometric hip adduction and plank exercise with isometric hip abduction than during traditional plank exercise. Internal oblique and external oblique muscle activities did not differ between the plank exercise with isometric hip adduction and plank exercise with isometric hip abduction conditions. [Conclusion] These findings demonstrate that loaded isometric hip movements may be a useful strategy to increase trunk muscle activity during plank exercises.

  13. The unique action of bi-articular muscles in complex movements.

    PubMed Central

    van Ingen Schenau, G J; Bobbert, M F; Rozendal, R H

    1987-01-01

    Actions of muscles that pass over more than one joint are mainly described with respect to movements in the joints that are crossed. In a previous study of push-off without plantar flexion it was shown that the transformation of knee angular velocity into translation of the body is constrained by the fact that velocity difference between hip and ankle has to reach its peak value a long time before the knee is extended. The present study was meant to test the hypothesis that the action of the gastrocnemius can be understood in the light of this constraint. Vertical jumps of ten subjects were analysed cinematographically. Electromyographic signals were derived from knee extensors and plantar flexors simultaneously. The results show that the peak velocity difference between hip and ankle is reached at a mean knee angle of 132 degrees. At that instant a rapid plantar flexion starts, reinforced by a strong increase of activation of gastrocnemius. It is suggested that the bi-articular character of the gastrocnemius muscle enables the knee extensors to continue to deliver work which is transported to the ankle where it is used for plantar flexion. This optimal use of the capabilities of proximally located muscles would not be possible if man had mono-articular muscles only. PMID:3503041

  14. Postural Control during Upper Body Locomotor-Like Movements: Similar Synergies Based on Dissimilar Muscle Modes

    PubMed Central

    Danna-Dos-Santos, Alessander; Shapkova, Elena Yu.; Shapkova, Alexandra L.; Degani, Adriana M.; Latash, Mark L.

    2009-01-01

    We studied the organization of leg and trunk muscles into groups (M-modes) and co-variation of M-mode involvement (M-mode synergies) during whole-body tasks associated with large variations of the moment of force about the vertical body axis. Our major questions were: (1) Can muscle activation patterns during such tasks be described with a few M-modes common across tasks and subjects? (2) Do these modes form the basis for synergies stabilizing MZ time pattern? (3) Will this organization differ between an explicit body rotation task and a task associated with locomotor-like alternating arm movements? Healthy subjects stood barefoot on the force platform and performed two motor tasks while paced by the metronome at 0.7, 1.0, and 1.4 Hz: Cyclic rotation of the upper body about the vertical body axis (body rotation task), and alternating rhythmic arm movements imitating those during running or quick walking (arm movement task). Principal component analysis was used to identify three M-modes within the space of integrated indices of muscle activity. The M-mode vectors showed clustering neither across subjects nor across frequencies. Variance in the M-mode space across sway cycles was partitioned into two components, one that did not affect the average value of MZ shift ("good variance") and the other that did. An index was computed reflecting the relative amount of the "good variance"; positive values of this index have been interpreted as reflecting a multi-M-mode synergy stabilizing the MZ trajectory. On average, the index was positive for both tasks and across all frequencies studied. However, the magnitude of the index was smaller for the intermediate frequency (1 Hz). The results show that the organization of muscles into groups during relatively complex whole-body tasks can differ significantly across both task variations and subjects. Nevertheless, the central nervous system seems to be able to build MZ stabilizing synergies based on different sets of M

  15. Ankle morphology amplifies calcaneus movement relative to triceps surae muscle shortening

    PubMed Central

    Csapo, R.; Hodgson, J.; Kinugasa, R.; Edgerton, V. R.

    2013-01-01

    The present study investigated the mechanical role of the dorsoventral curvature of the Achilles tendon in the conversion of the shortening of the plantarflexor muscles into ankle joint rotation. Dynamic, sagittal-plane magnetic resonance spin-tagged images of the ankle joint were acquired in six healthy subjects during both passive and active plantarflexion movements driven by a magnetic resonance compatible servomotor-controlled foot-pedal device. Several points on these images were tracked to determine the 1) path and deformation of the Achilles tendon, 2) ankle's center of rotation, and 3) tendon moment arms. The degree of mechanical amplification of joint movement was calculated as the ratio of the displacements of the calcaneus and myotendinous junction. In plantarflexion, significant deflection of the Achilles tendon was evident in both the passive (165.7 ± 7.4°; 180° representing a straight tendon) and active trials (166.9 ± 8.8°). This bend in the dorsoventral direction acts to move the Achilles tendon closer to the ankle's center of rotation, resulting in an ∼5% reduction of moment arm length. Over the entire range of movement, the overall displacement of the calcaneus exceeded the displacement of the myotendinous junction by ∼37%, with the mechanical gains being smaller in dorsi- and larger in plantarflexed joint positions. This is the first study to assess noninvasively and in vivo using MRI the curvature of the Achilles tendon during both passive and active plantarflexion movements. The dorsoventral tendon curvature amplifies the shortening of the plantarflexor muscles, resulting in a greater displacement of the tendon's insertion into the calcaneus compared with its origin. PMID:23743400

  16. Ankle morphology amplifies calcaneus movement relative to triceps surae muscle shortening.

    PubMed

    Csapo, R; Hodgson, J; Kinugasa, R; Edgerton, V R; Sinha, S

    2013-08-15

    The present study investigated the mechanical role of the dorsoventral curvature of the Achilles tendon in the conversion of the shortening of the plantarflexor muscles into ankle joint rotation. Dynamic, sagittal-plane magnetic resonance spin-tagged images of the ankle joint were acquired in six healthy subjects during both passive and active plantarflexion movements driven by a magnetic resonance compatible servomotor-controlled foot-pedal device. Several points on these images were tracked to determine the 1) path and deformation of the Achilles tendon, 2) ankle's center of rotation, and 3) tendon moment arms. The degree of mechanical amplification of joint movement was calculated as the ratio of the displacements of the calcaneus and myotendinous junction. In plantarflexion, significant deflection of the Achilles tendon was evident in both the passive (165.7 ± 7.4°; 180° representing a straight tendon) and active trials (166.9 ± 8.8°). This bend in the dorsoventral direction acts to move the Achilles tendon closer to the ankle's center of rotation, resulting in an ∼5% reduction of moment arm length. Over the entire range of movement, the overall displacement of the calcaneus exceeded the displacement of the myotendinous junction by ∼37%, with the mechanical gains being smaller in dorsi- and larger in plantarflexed joint positions. This is the first study to assess noninvasively and in vivo using MRI the curvature of the Achilles tendon during both passive and active plantarflexion movements. The dorsoventral tendon curvature amplifies the shortening of the plantarflexor muscles, resulting in a greater displacement of the tendon's insertion into the calcaneus compared with its origin.

  17. Plane of vertebral movement eliciting muscle lengthening history in the low back influences the decrease in muscle spindle responsiveness of the cat.

    PubMed

    Ge, Weiqing; Cao, Dong-Yuan; Long, Cynthia R; Pickar, Joel G

    2011-12-01

    Proprioceptive feedback is thought to play a significant role in controlling both lumbopelvic and intervertebral orientations. In the lumbar spine, a vertebra's positional history along the dorsal-ventral axis has been shown to alter the position, movement, and velocity sensitivity of muscle spindles in the multifidus and longissimus muscles. These effects appear due to muscle history. Because spinal motion segments have up to 6 degrees of freedom for movement, we were interested in whether the axis along which the history is applied differentially affects paraspinal muscle spindles. We tested the null hypothesis that the loading axis, which creates a vertebra's positional history, has no effect on a lumbar muscle spindle's subsequent response to vertebral position or movement. Identical displacements were applied along three orthogonal axes directly at the L(6) spinous process using a feedback motor system under displacement control. Single-unit nerve activity was recorded from 60 muscle spindle afferents in teased filaments from L(6) dorsal rootlets innervating intact longissimus or multifidus muscles of deeply anesthetized cats. Muscle lengthening histories along the caudal-cranial and dorsal-ventral axis, compared with the left-right axis, produced significantly greater reductions in spindle responses to vertebral position and movement. The spinal anatomy suggested that the effect of a lengthening history is greatest when that history had occurred along an axis lying within the anatomical plane of the facet joint. Speculation is made that the interaction between normal spinal mechanics and the inherent thixotropic property of muscle spindles poses a challenge for feedback and feedforward motor control of the lumbar spine.

  18. Effects of weightlessness and movement restriction on the structure and metabolism of the soleus muscle in monkeys after space flight.

    PubMed

    Shenkman, B S; Belozerova, I N; Lee, Peter; Nemirovskaya, T L; Kozlovskaya, I B

    2003-09-01

    After humans and animals have been in conditions of real and modeled weightlessness, the most marked changes are seen in the "slow" tonic muscles, particularly soleus. Studies of the effects of weightlessness and movement restriction on the soleus muscle in monkeys demonstrated significant reductions in the sizes of slow and rapid fibers due mainly to the actions of real weightlessness (rather than movement restriction in the space capsule). Protein loss in soleus muscle fibers in monkeys following space flight was more marked than loss of other components, including water. The level of atrophy of soleus muscle fibers in these conditions was greater than the decrease in the number of capillaries. Succinate dehydrogenase activity in soleus muscle fibers decreased proportionally to the reduction in fiber size.

  19. Muscle co-activity tuning in Parkinsonian hand movement: disease-specific changes at behavioral and cerebral level

    PubMed Central

    van der Stouwe, A. M. M.; Toxopeus, C. M.; de Jong, B. M.; Yavuz, P.; Valsan, G.; Conway, B. A.; Leenders, K. L.; Maurits, N. M.

    2015-01-01

    We investigated simple directional hand movements based on different degrees of muscle co-activity, at behavioral and cerebral level in healthy subjects and Parkinson's disease (PD) patients. We compared “singular” movements, dominated by the activity of one agonist muscle, to “composite” movements, requiring conjoint activity of multiple muscles, in a center-out (right hand) step-tracking task. Behavioral parameters were obtained by EMG and kinematic recordings. fMRI was used to investigate differences in underlying brain activations between PD patients (N = 12) and healthy (age-matched) subjects (N = 18). In healthy subjects, composite movements recruited the striatum and cortical areas comprising bilaterally the supplementary motor area and premotor cortex, contralateral medial prefrontal cortex, primary motor cortex, primary visual cortex, and ipsilateral superior parietal cortex. Contrarily, the ipsilateral cerebellum was more involved in singular movements. This striking dichotomy between striatal and cortical recruitment vs. cerebellar involvement was considered to reflect the complementary roles of these areas in motor control, in which the basal ganglia are involved in movement selection and the cerebellum in movement optimization. Compared to healthy subjects, PD patients showed decreased activation of the striatum and cortical areas in composite movement, while performing worse at behavioral level. This implies that PD patients are especially impaired on tasks requiring highly tuned muscle co-activity. Singular movement, on the other hand, was characterized by a combination of increased activation of the ipsilateral parietal cortex and left cerebellum. As singular movement performance was only slightly compromised, we interpret this as a reflection of increased visuospatial processing, possibly as a compensational mechanism. PMID:26300761

  20. A real-time system for biomechanical analysis of human movement and muscle function.

    PubMed

    van den Bogert, Antonie J; Geijtenbeek, Thomas; Even-Zohar, Oshri; Steenbrink, Frans; Hardin, Elizabeth C

    2013-10-01

    Mechanical analysis of movement plays an important role in clinical management of neurological and orthopedic conditions. There has been increasing interest in performing movement analysis in real-time, to provide immediate feedback to both therapist and patient. However, such work to date has been limited to single-joint kinematics and kinetics. Here we present a software system, named human body model (HBM), to compute joint kinematics and kinetics for a full body model with 44 degrees of freedom, in real-time, and to estimate length changes and forces in 300 muscle elements. HBM was used to analyze lower extremity function during gait in 12 able-bodied subjects. Processing speed exceeded 120 samples per second on standard PC hardware. Joint angles and moments were consistent within the group, and consistent with other studies in the literature. Estimated muscle force patterns were consistent among subjects and agreed qualitatively with electromyography, to the extent that can be expected from a biomechanical model. The real-time analysis was integrated into the D-Flow system for development of custom real-time feedback applications and into the gait real-time analysis interactive lab system for gait analysis and gait retraining.

  1. Special involuntary conversion situations involving timberland

    Treesearch

    William C. Siegal

    2001-01-01

    If standing timber is destroyed or stolen, or if forest land is condemned for public use, the owner may be entitled to take a deduction on his or her income tax return. These types of losses are called involuntary conversions. In previous National Woodlands articles I've discussed in detail casualty losses, which represent the major type of timber involuntary...

  2. 5 CFR 842.206 - Involuntary retirement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Involuntary retirement. 842.206 Section 842.206 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.206 Involuntary...

  3. 5 CFR 842.206 - Involuntary retirement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Involuntary retirement. 842.206 Section 842.206 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.206 Involuntary...

  4. 5 CFR 842.206 - Involuntary retirement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Involuntary retirement. 842.206 Section 842.206 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.206 Involuntary...

  5. 5 CFR 842.206 - Involuntary retirement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Involuntary retirement. 842.206 Section 842.206 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.206 Involuntary...

  6. Control of Leg Movements Driven by EMG Activity of Shoulder Muscles

    PubMed Central

    La Scaleia, Valentina; Sylos-Labini, Francesca; Hoellinger, Thomas; Wang, Letian; Cheron, Guy; Lacquaniti, Francesco; Ivanenko, Yuri P.

    2014-01-01

    During human walking, there exists a functional neural coupling between arms and legs, and between cervical and lumbosacral pattern generators. Here, we present a novel approach for associating the electromyographic (EMG) activity from upper limb muscles with leg kinematics. Our methodology takes advantage of the high involvement of shoulder muscles in most locomotor-related movements and of the natural co-ordination between arms and legs. Nine healthy subjects were asked to walk at different constant and variable speeds (3–5 km/h), while EMG activity of shoulder (deltoid) muscles and the kinematics of walking were recorded. To ensure a high level of EMG activity in deltoid, the subjects performed slightly larger arm swinging than they usually do. The temporal structure of the burst-like EMG activity was used to predict the spatiotemporal kinematic pattern of the forthcoming step. A comparison of actual and predicted stride leg kinematics showed a high degree of correspondence (r > 0.9). This algorithm has been also implemented in pilot experiments for controlling avatar walking in a virtual reality setup and an exoskeleton during over-ground stepping. The proposed approach may have important implications for the design of human–machine interfaces and neuroprosthetic technologies such as those of assistive lower limb exoskeletons. PMID:25368569

  7. Real-time estimation of tongue movement based on suprahyoid muscle activity.

    PubMed

    Sasaki, M; Onishi, K; Arakawa, T; Nakayama, A; Stefanov, D; Yamaguchi, M

    2013-01-01

    In this study, we introduce a real-time method for tongue movement estimation based on the analysis of the surface electromyography (EMG) signals from the suprahyoid muscles, which usual function is to open the mouth and to control the position of the hyoid, the base of the tongue. Nine surface electrodes were affixed to the underside of the jaw and their signals were processed via multi-channel EMG system. The features of the EMG signals were extracted by using a root mean square (RMS) method. The dimension of the variables was reduced additionally from 108 to 10 by applying the Principal Component Analysis (PCA). The feature quantities of the reduced dimension set were associated with the tongue movements by using an artificial neural network. Results showed that the proposed method allows precise estimation of the tongue movements. For the test data set, the identification rate was greater than 97 % and the response time was less than 0.7 s. The proposed method could be implemented to facilitate novel approaches for alternative communication and control of assistive technology for supporting the independent living of people with severe quadriplegia.

  8. Pioneers of eye movement research

    PubMed Central

    Wade, Nicholas J

    2010-01-01

    Recent advances in the technology affording eye movement recordings carry the risk of neglecting past achievements. Without the assistance of this modern armoury, great strides were made in describing the ways the eyes move. For Aristotle the fundamental features of eye movements were binocular, and he described the combined functions of the eyes. This was later given support using simple procedures like placing a finger over the eyelid of the closed eye and culminated in Hering's law of equal innervation. However, the overriding concern in the 19th century was with eye position rather than eye movements. Appreciating discontinuities of eye movements arose from studies of vertigo. The characteristics of nystagmus were recorded before those of saccades and fixations. Eye movements during reading were described by Hering and by Lamare in 1879; both used similar techniques of listening to sounds made during contractions of the extraocular muscles. Photographic records of eye movements during reading were made by Dodge early in the 20th century, and this stimulated research using a wider array of patterns. In the mid-20th century attention shifted to the stability of the eyes during fixation, with the emphasis on involuntary movements. The contributions of pioneers from Aristotle to Yarbus are outlined. PMID:23396982

  9. Warm-up with weighted bat and adjustment of upper limb muscle activity in bat swinging under movement correction conditions.

    PubMed

    Ohta, Yoichi; Ishii, Yasumitsu; Ikudome, Sachi; Nakamoto, Hiroki

    2014-02-01

    The effects of weighted bat warm-up on adjustment of upper limb muscle activity were investigated during baseball bat swinging under dynamic conditions that require a spatial and temporal adjustment of the swinging to hit a moving target. Seven male college baseball players participated in this study. Using a batting simulator, the task was to swing the standard bat coincident with the arrival timing and position of a moving target after three warm-up swings using a standard or weighted bat. There was no significant effect of weighted bat warm-up on muscle activity before impact associated with temporal or spatial movement corrections. However, lower inhibition of the extensor carpi ulnaris muscle activity was observed in a velocity-changed condition in the weighted bat warm-up, as compared to a standard bat warm-up. It is suggested that weighted bat warm-up decreases the adjustment ability associated with inhibition of muscle activation under movement correction conditions.

  10. Movements elicited by electrical stimulation of muscles, nerves, intermediate spinal cord, and spinal roots in anesthetized and decerebrate cats.

    PubMed

    Aoyagi, Yoichiro; Mushahwar, Vivian K; Stein, Richard B; Prochazka, Arthur

    2004-03-01

    Electrical stimulation offers the possibility of restoring motor function of paralyzed limbs after spinal-cord injury or stroke, but few data are available to compare possible sites of stimulation, such as muscle, nerve, spinal roots, or spinal cord. The aim of this study was to establish some characteristics of stimulation at these sites in the anesthetized and midcollicular decerebrate cat. The hind limb was constrained to move in the sagittal plane against a spring load. Ventral-root stimulation only produced movements down and back; the direction moved systematically backward the more caudal the stimulated roots. In contrast, dorsal-root stimulation only produced movements up and forward. Thus, neither method alone could produce the full range of normal movements. Muscle, nerve, and intraspinal stimulation within the intermediate regions of the gray matter generated discrete, selective movements in a wide range of directions. Muscle stimulation required an order of magnitude more current. Single microwire electrodes located in the spinal gray matter could activate a synergistic group of muscles, and generally had graded recruitment curves, but the direction of movement occasionally changed abruptly as stimulus strength increased. Nerve stimulation produced the largest movements against the spring load (>80% of the passive range of motion) and was the most reproducible from animal to animal. However, recruitment curves with nerve stimulation were quite steep, so fine control of movement might be difficult. The muscle, nerve, and spinal cord all seem to be feasible sites to restore motor function. The pros and cons from this study may be helpful in deciding the best site for a particular application, but further tests are needed in the chronically transected spinal cord to assess the applicability of these results to human patients.

  11. Slow temporal filtering may largely explain the transformation of stick insect (Carausius morosus) extensor motor neuron activity into muscle movement.

    PubMed

    Hooper, Scott L; Guschlbauer, Christoph; von Uckermann, Géraldine; Büschges, Ansgar

    2007-09-01

    Understanding how nervous systems generate behavior requires understanding how muscles transform neural input into movement. The stick insect extensor tibiae muscle is an excellent system in which to study this issue because extensor motor neuron activity is highly variable during single leg walking and extensor muscles driven with this activity produce highly variable movements. We showed earlier that spike number, not frequency, codes for extensor amplitude during contraction rises, which implies the muscle acts as a slow filter on the time scale of burst interspike intervals (5-10 ms). We examine here muscle response to spiking variation over entire bursts, a time scale of hundreds of milliseconds, and directly measure muscle time constants. Muscle time constants differ during contraction and relaxation, and contraction time constants, although variable, are always extremely slow (200-700 ms). Models using these data show that extremely slow temporal filtering alone can explain much of the observed transform properties. This work also revealed an unexpected (to us) ability of slow filtering to transform steadily declining inputs into constant amplitude outputs. Examination of the effects of time constant variability on model output showed that variation within an SD primarily altered output amplitude, but variation across the entire range also altered contraction shape. These substantial changes suggest that understanding the basis of this variation is central to predicting extensor activity and that the animal could theoretically vary muscle time constant to match extensor response to changing behavioral need.

  12. [Biomechanical and physiological substantiation for application of functional muscle electrostimulation in performing rhythmic movements on bicycle ergometer].

    PubMed

    Petrushanskaia, K A; Vitenzon, A S; Gritsenko, G P; Sutchenkov, I A

    2004-01-01

    Kinematic and electromyographic parameters in conduction of rhythmic movements on the bicycle ergometer were studied in a group of healthy subjects. It is shown that these movements are characterized by a stable biomechanical and innervation stereotype consisting of two interacting synergies: flexor and extensor. Force extensor synergy plays the key role which provides both triggering and maintenance of certain rhythm of rotation. Flexor synergy is primarily corrective. Basing on the data obtained, stimulated muscles are selected in basic phases of the cycle, algorithms of time and amplitude programs of muscle electrostimulation in conduction of bicycle ergometry are proposed.

  13. Instability in human forearm movements studied with feed-back-controlled electrical stimulation of muscles.

    PubMed

    Jacks, A; Prochazka, A; Trend, P S

    1988-08-01

    1. Amplitude-modulated electrical stimulation was applied to the elbow flexors and extensors to produce movements of the forearm in normal subjects. The parameters of the modulating (command) signal were set in isometric trials so as to produce equal and opposite background torques, and equal and supportive torque modulations. 2. Bode plots relating forearm movement to command signal (modulating) frequency showed the muscle-load to have a low-pass characteristic similar to that previously described in the cat, and a slightly larger bandwidth than described previously in man. 3. The transduced forearm signals were fed back to provide the command signal to the stimulators via a filter which mimicked the transfer function of muscle spindle primary endings. In effect this replaced the neural part of the reflex arc with an accessible model, but left the muscle-load effector intact. 4. All six subjects developed forearm oscillations (tremor) when the loop gain exceeded a threshold value. The mean tremor frequency at onset was 4.4 Hz, which was similar to that of the equivalent vibration-evoked tremor (previous paper, Prochazka & Trend, 1988). 5. With the linear spindle model, oscillations tended to grow rapidly in amplitude, and the stimuli became painful. The inclusion of a logarithmic limiting element resulted in stable oscillations, without significant alterations in frequency. This allowed us to study the effect on tremor of including analog delays in the loop, mimicking those associated with peripheral nerve transmission and central reflexes. In one subject, loop delays of 0, 20, 40 and 100 ms resulted in tremor at 4.0, 3.6, 3.0 and 2.1 Hz respectively, as quantified by spectral analysis. 6. By considering separately the phase contributions of the different elements of the reflex arc, including delays, it became clear that muscle-load properties were important in setting the upper limit of tremor frequencies which could conceivably be supported by reflexes. 7. The

  14. Comparison of lower limb muscle activation with ballet movements (releve and demi-plie) and general movements (heel rise and squat) in healthy adults

    PubMed Central

    Kim, Min-Ju; Kim, Joong-Hwi

    2016-01-01

    [Purpose] The aim of this study was to demonstrate therapeutic grounds for rehabilitation exercise approach by comparing and analyzing muscular activities of Ballet movements: the releve movement (RM) and the demi-plie movement (DM). [Methods] Four types of movements such as RM vs. heel rise (HM) and DM vs. squat movement (SM) were randomized and applied in 30 healthy male and female individuals while measuring 10-s lower limb muscular activities (gluteus maximus [GMa], gluteus medius [GMe], rectus femoris [RF], adductor longus [AL], medial gastrocnemius [MG], and lateral gastrocnemius [LG]) by using surface electromyography (EMG). [Results] Significant differences were found in GMa, GMe, AL and MG activities for DM and in all of the six muscles for RM, in particular when the two groups were compared (RM vs HM and DM vs SM). [Conclusion] The RM and DM have a greater effect on lower limb muscular force activities compared to HM and SM and could be recommended as clinical therapeutic exercises for lower limb muscle enhancement. PMID:26957762

  15. Effect of postnatal development on calcium currents and slow charge movement in mammalian skeletal muscle

    PubMed Central

    Beam, KG; Knudson, CM

    1988-01-01

    Single- (whole-cell patch) and two-electrode voltage-clamp techniques were used to measure transient (Ifast) and sustained (Islow) calcium currents, linear capacitance, and slow, voltage-dependent charge movements in freshly dissociated fibers of the flexor digitorum brevis (FDB) muscle of rats of various postnatal ages. Peak Ifast was largest in FDB fibers of neonatal (1-5 d) rats, having a magnitude in 10 mM external Ca of 1.4 +/- 0.9 pA/pF (mean +/- SD; current normalized by linear fiber capacitance). Peak Ifast was smaller in FDB fibers of older animals, and by approximately 3 wk postnatal, it was so small as to be unmeasurable. By contrast, the magnitudes of Islow and charge movement increased substantially during postnatal development. Peak Islow was 3.6 +/- 2.5 pA/pF in FDB fibers of 1-5-d rats and increased to 16.4 +/- 6.5 pA/pF in 45-50-d-old rats; for these same two age groups, Qmax, the total mobile charge measurable as charge movement, was 6.0 +/- 1.7 and 23.8 +/- 4.0 nC/microF, respectively. As both Islow and charge movement are thought to arise in the transverse-tubular system, linear capacitance normalized by the area of fiber surface was determined as an indirect measure of the membrane area of the t-system relative to that of the fiber surface. This parameter increased from 1.5 +/- 0.2 microF/cm2 in 2-d fibers to 2.9 +/- 0.4 microF/cm2 in 44-d fibers. The increases in peak Islow, Qmax, and normalized linear capacitance all had similar time courses. Although the function of Islow is unknown, the substantial postnatal increase in its magnitude suggests that it plays an important role in the physiology of skeletal muscle. PMID:2458430

  16. Movement.

    ERIC Educational Resources Information Center

    Roberts, Lynda S.

    This document summarizes 20 articles and books which stress the importance of movement in the overall development of the human species. Each summary ranges in length from 100 to 200 words and often includes direct quotations. A wide range of movement activities suitable for people of all ages (from infants to adults) are discussed. Many summaries…

  17. A passive movement method for parameter estimation of a musculo-skeletal arm model incorporating a modified hill muscle model.

    PubMed

    Yu, Tung Fai; Wilson, Adrian J

    2014-05-01

    In this paper we present an experimental method of parameterising the passive mechanical characteristics of the bicep and tricep muscles in vivo, by fitting the dynamics of a two muscle arm model incorporating anatomically meaningful and structurally identifiable modified Hill muscle models to measured elbow movements. Measurements of the passive flexion and extension of the elbow joint were obtained using 3D motion capture, from which the elbow angle trajectories were determined and used to obtain the spring constants and damping coefficients in the model through parameter estimation. Four healthy subjects were used in the experiments. Anatomical lengths and moment of inertia values of the subjects were determined by direct measurement and calculation. There was good reproducibility in the measured arm movement between trials, and similar joint angle trajectory characteristics were seen between subjects. Each subject had their own set of fitted parameter values determined and the results showed good agreement between measured and simulated data. The average fitted muscle parallel spring constant across all subjects was 143 N/m and the average fitted muscle parallel damping constant was 1.73 Ns/m. The passive movement method was proven to be successful, and can be applied to other joints in the human body, where muscles with similar actions are grouped together. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  18. Feedforward activity of the cervical flexor muscles during voluntary arm movements is delayed in chronic neck pain.

    PubMed

    Falla, D; Jull, G; Hodges, P W

    2004-07-01

    The objective of this study was to compare onset of deep and superficial cervical flexor muscle activity during rapid, unilateral arm movements between ten patients with chronic neck pain and 12 control subjects. Deep cervical flexor (DCF) electromyographic activity (EMG) was recorded with custom electrodes inserted via the nose and fixed by suction to the posterior mucosa of the oropharynx. Surface electrodes were placed over the sternocleidomastoid (SCM) and anterior scalene (AS) muscles. While standing, subjects flexed and extended the right arm in response to a visual stimulus. For the control group, activation of DCF, SCM and AS muscles occurred less than 50 ms after the onset of deltoid activity, which is consistent with feedforward control of the neck during arm flexion and extension. When subjects with a history of neck pain flexed the arm, the onsets of DCF and contralateral SCM and AS muscles were significantly delayed ( p<0.05). It is concluded that the delay in neck muscle activity associated with movement of the arm in patients with neck pain indicates a significant deficit in the automatic feedforward control of the cervical spine. As the deep cervical muscles are fundamentally important for support of the cervical lordosis and the cervical joints, change in the feedforward response may leave the cervical spine vulnerable to reactive forces from arm movement.

  19. The spinal reflex cannot be perceptually separated from voluntary movements.

    PubMed

    Ghosh, Arko; Haggard, Patrick

    2014-01-01

    Both voluntary and involuntary movements activate sensors in the muscles, skin, tendon and joints. As limb movement can result from a mixture of spinal reflexes and voluntary motor commands, the cortical centres underlying conscious proprioception might either aggregate or separate the sensory inputs generated by voluntary movements from those generated by involuntary movements such as spinal reflexes. We addressed whether healthy volunteers could perceive the contribution of a spinal reflex during movements that combined both reflexive and voluntary contributions. Volunteers reported the reflexive contribution in leg movements that were partly driven by the knee-jerk reflex induced by a patellar tendon tap and partly by voluntary motor control. In one condition, participants were instructed to kick back in response to a tendon tap. The results were compared to reflexes in a resting baseline condition without voluntary movement. In a further condition, participants were instructed to kick forwards after a tap. Volunteers reported the perceived reflex contribution by repositioning the leg to the perceived maximum displacement to which the reflex moved the leg after each tendon tap. In the resting baseline condition, the reflex was accurately perceived. We found a near-unity slope of linear regressions of perceived on actual reflexive displacement. Both the slope value and the quality of regression fit in individual volunteers were significantly reduced when volunteers were instructed to generate voluntary backward kicks as soon as they detected the tap. In the kick forward condition, kinematic analysis showed continuity of reflex and voluntary movements, but the reflex contribution could be estimated from electromyography (EMG) recording on each trial. Again, participants' judgements of reflexes showed a poor relation to reflex EMG, in contrast to the baseline condition. In sum, we show that reflexes can be accurately perceived from afferent information. However

  20. The spinal reflex cannot be perceptually separated from voluntary movements

    PubMed Central

    Ghosh, Arko; Haggard, Patrick

    2014-01-01

    Abstract Both voluntary and involuntary movements activate sensors in the muscles, skin, tendon and joints. As limb movement can result from a mixture of spinal reflexes and voluntary motor commands, the cortical centres underlying conscious proprioception might either aggregate or separate the sensory inputs generated by voluntary movements from those generated by involuntary movements such as spinal reflexes. We addressed whether healthy volunteers could perceive the contribution of a spinal reflex during movements that combined both reflexive and voluntary contributions. Volunteers reported the reflexive contribution in leg movements that were partly driven by the knee-jerk reflex induced by a patellar tendon tap and partly by voluntary motor control. In one condition, participants were instructed to kick back in response to a tendon tap. The results were compared to reflexes in a resting baseline condition without voluntary movement. In a further condition, participants were instructed to kick forwards after a tap. Volunteers reported the perceived reflex contribution by repositioning the leg to the perceived maximum displacement to which the reflex moved the leg after each tendon tap. In the resting baseline condition, the reflex was accurately perceived. We found a near-unity slope of linear regressions of perceived on actual reflexive displacement. Both the slope value and the quality of regression fit in individual volunteers were significantly reduced when volunteers were instructed to generate voluntary backward kicks as soon as they detected the tap. In the kick forward condition, kinematic analysis showed continuity of reflex and voluntary movements, but the reflex contribution could be estimated from electromyography (EMG) recording on each trial. Again, participants’ judgements of reflexes showed a poor relation to reflex EMG, in contrast to the baseline condition. In sum, we show that reflexes can be accurately perceived from afferent information

  1. The postural control can be optimized by the first movement initiation condition encountered when submitted to muscle fatigue.

    PubMed

    Monjo, Florian; Forestier, Nicolas

    2017-08-01

    We investigated whether and how the movement initiation condition (IC) encountered during the early movements performed following focal muscle fatigue affects the postural control of discrete ballistic movements. For this purpose, subjects performed shoulder flexions in a standing posture at maximal velocity under two movement IC, i.e., in self-paced conditions and submitted to a Stroop-like task in which participants had to trigger fast shoulder flexions at the presentation of incongruent colors. Shoulder flexion kinematics, surface muscle activity of focal and postural muscles as well as center-of-pressure kinematics were recorded. The initial IC and the order in which subjects were submitted to these two conditions were varied within two separate experimental sessions. IC schedule was repeated before and after fatigue protocols involving shoulder flexors. The aim of this fatigue procedure was to affect acceleration-generating capacities of focal muscles. In such conditions, the postural muscle activity preceding and accompanying movement execution is expected to decrease. Following fatigue, when subjects initially moved in self-paced conditions, postural muscle activity decreased and scaled to the lower focal peak acceleration. This postural strategy then transferred to the Stroop-like task. In contrast, when subjects initially moved submitted to the Stroop-like task, postural muscle activity did not decrease and this transferred to self-paced movements. Regarding the center-of-pressure peak velocity, which is indicative of the efficiency of the postural actions generated in stabilizing posture, no difference appeared between the two sessions post-fatigue. This highlights an optimization of the postural actions when subjects first moved in self-paced conditions, smaller postural muscle activation levels resulting in similar postural consequences. In conclusion, the level of neuromuscular activity associated with the postural control is affected and can be

  2. Prolonging the duration of masseter muscle reduction by adjusting the masticatory movements after the treatment of masseter muscle hypertrophy with botulinum toxin type a injection.

    PubMed

    Wei, Jiao; Xu, Hua; Dong, Jiasheng; Li, Qingfeng; Dai, Chuanchang

    2015-01-01

    Botulinum toxin type A (BTX-A) is widely used for the clinical treatment of masseteric hypertrophy. Until now, few reports have discussed how to prolong the duration of its effectiveness. This study evaluated that purposely adjusting the masticatory movements is possible of postponing the masseter muscle rehypertrophy. Ninety-eight patients were randomly and equally divided into 2 groups, and 35 U BTX-A per side was injected into the masseters. The thickness and volume of the masticatory muscles were measured by ultrasound and computerized tomography, respectively. Patients in Group 1 were instructed to strengthen their masticatory effort during the denervated atrophic stage of the masseter (the interval was evaluated by real-time ultrasound monitoring), whereas patients in Group 2 were not given this instruction. When the masseter muscle began to recover, patients in both groups were instructed to reduce their chewing. The duration of the masseter muscle rehypertrophy was significantly prolonged in Group 1 patients. The thickness and the volume of the other masticatory muscles were significantly increased in Group 1 but were either slightly decreased or insignificantly different in Group 2. Purposely strengthening masticatory muscle movement during the denervated atrophic stage of the masseter can prolong the duration of masseter rehypertrophy.

  3. Electric Eels Concentrate Their Electric Field to Induce Involuntary Fatigue in Struggling Prey.

    PubMed

    Catania, Kenneth C

    2015-11-16

    Nature is replete with predator venoms that immobilize prey by targeting ion channels. Electric eels (Electrophorus electricus) take a different tactic to accomplish the same end. Striking eels emit electricity in volleys of 1 ms, high-voltage pulses. Each pulse is capable of activating prey motor neuron efferents, and hence muscles. In a typical attack, eel discharges cause brief, immobilizing tetanus, allowing eels to swallow small prey almost immediately. Here I show that when eels struggle with large prey or fish held precariously, they commonly curl to bring their own tail to the opposite side of prey, sandwiching it between the two poles of their powerful electric organ. They then deliver volleys of high-voltage pulses. Shortly thereafter, eels juggle prey into a favorable position for swallowing. Recordings from electrodes placed within prey items show that this curling behavior at least doubles the field strength within shocked prey, most likely ensuring reliable activation of the majority of prey motor neurons. Simulated pulse trains, or pulses from an eel-triggered stimulator, applied to a prey muscle preparations result in profound muscle fatigue and loss of contractile force. Consistent with this result, video recordings show that formerly struggling prey are temporarily immobile after this form of attack, allowing the manipulation of prey that might otherwise escape. These results reveal a unique use of electric organs to a unique end; eels superimpose electric fields from two poles, ensuring maximal remote activation of prey efferents that blocks subsequent prey movement by inducing involuntary muscle fatigue. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Abnormal vibration induced illusion of movement in essential tremor: evidence for abnormal muscle spindle afferent function

    PubMed Central

    Frima, N; Grunewald, R

    2005-01-01

    Objectives: Vibration induced illusion of movement (VIIM) is abnormal in patients with idiopathic focal dystonia, an abnormality which corrects with fatigue of the vibrated muscle. Since dystonia and essential tremor sometimes coexist in families, we investigated the perception of VIIM and the effect of fatigue on VIIM in patients with essential tremor. Methods: VIIM in 18 patients with essential tremor was compared with VIIM in 18 healthy control participants before and after volitional fatigue of the vibrated muscles. Results: Vibration of the immobilised biceps produced a subnormal VIIM in patients with essential tremor (12.81° (SEM 2.15)) compared with healthy control subjects (28.55° (1.66)). The perception increased following volitional fatigue of the vibrated arm in patients with essential tremor (16.23° (2.50)) but not in healthy controls (27.55° (1.66)). No difference was observed in patients with alcohol or non-alcohol responsive tremor. Conclusions: The VIIM decreased with increasing age in healthy control subjects. Abnormal VIIM implies abnormal sensorimotor processing in patients with essential tremor, similar to that found in idiopathic focal dystonia, and the change of the perception with age could explain the age related onset of the disorder. PMID:15607995

  5. Converting biomechanical energy into electricity by a muscle-movement-driven nanogenerator.

    PubMed

    Yang, Rusen; Qin, Yong; Li, Cheng; Zhu, Guang; Wang, Zhong Lin

    2009-03-01

    A living species has numerous sources of mechanical energy, such as muscle stretching, arm/leg swings, walking/running, heart beats, and blood flow. We demonstrate a piezoelectric nanowire based nanogenerator that converts biomechanical energy, such as the movement of a human finger and the body motion of a live hamster (Campbell's dwarf), into electricity. A single wire generator (SWG) consists of a flexible substrate with a ZnO nanowire affixed laterally at its two ends on the substrate surface. Muscle stretching results in the back and forth stretching of the substrate and the nanowire. The piezoelectric potential created inside the wire leads to the flow of electrons in the external circuit. The output voltage has been increased by integrating multiple SWGs. A series connection of four SWGs produced an output voltage of up to approximately 0.1-0.15 V. The success of energy harvesting from a tapping finger and a running hamster reveals the potential of using the nanogenerators for scavenging low-frequency energy from regular and irregular biomotion.

  6. Effect of the calcium buffer EGTA on the "hump" component of charge movement in skeletal muscle

    PubMed Central

    1991-01-01

    Three manifestations of excitation-contraction (E-C) coupling were measured in cut skeletal muscle fibers of the frog, voltage clamped in a double Vaseline gap: intramembrane charge movements, myoplasmic Ca2+ transients, and changes in optical transparency. Pulsing patterns in the presence of high [EGTA] intracellularly, shown by Garcia et al. (1989. J. Gen. Physiol. 94:973-986) to deplete Ca2+ in the sarcoplasmic reticulum, were found to change the above manifestations. With an intracellular solution containing 15 mM EGTA and 0 Ca, 10-15 pulses (100 ms) to -20 mV at a frequency of 2 min-1 reduced the "hump" component of charge movement current. This effect was reversible by 5 min of rest. The same effect was obtained in 62.5 mM EGTA and 0 Ca by pulsing at 0.2 min-1. This effect was reversible by adding calcium to the EGTA solution, for a nominal [Ca2+]i of 200 nM, and was prevented by adding calcium to the EGTA solution before pulsing. The suppression of the hump was accompanied by elimination of the optical manifestations of E-C coupling. The current suppressed was found by subtraction and had the following properties: delayed onset, a peak at a variable interval (10-20 ms) into the pulse, a negative phase (inward current) after the peak, and a variable OFF transient that could be multi-phasic and carried less charge than the ON transient. In the previous paper (Csernoch et al., 1991. J. Gen. Physiol. 97:845-884) it was shown that several interventions suppress a similar component of charge movement current, identified with the "hump" or Q gamma current (I gamma). Based on the similarity to that component, the charge movement suppressed by the depletion protocols can also be identified with I gamma. The fact that I gamma is suppressed by Ca2+ depletion and the kinetic properties of the charge suppressed is inconsistent with the existence of separate sets of voltage sensors underlying the two components of charge movement, Q beta and Q gamma. This is explicable if

  7. Tropomyosin movement on F-actin during muscle activation explained by energy landscapes.

    PubMed

    Orzechowski, Marek; Moore, Jeffrey R; Fischer, Stefan; Lehman, William

    2014-03-01

    Muscle contraction is regulated by tropomyosin movement across the thin filament surface, which exposes or blocks myosin-binding sites on actin. Recent atomic structures of F-actin-tropomyosin have yielded the positions of tropomyosin on myosin-free and myosin-decorated actin. Here, the repositioning of α-tropomyosin between these locations on F-actin was systematically examined by optimizing the energy of the complex for a wide range of tropomyosin positions on F-actin. The resulting energy landscape provides a full-map of the F-actin surface preferred by tropomyosin, revealing a broad energy basin associated with the tropomyosin position that blocks myosin-binding. This is consistent with previously proposed low-energy oscillations of semi-rigid tropomyosin, necessary for shifting of tropomyosin following troponin-binding. In contrast, the landscape shows much less favorable energies when tropomyosin locates near its myosin-induced "open-state" position. This indicates that spontaneous movement of tropomyosin away from its energetic "ground-state" to the open-state is unlikely in absence of myosin. Instead, myosin-binding must drive tropomyosin toward the open-state to activate the thin filament. Additional energy landscapes were computed for disease-causing actin mutants that distort the topology of the actin-tropomyosin energy landscape, explaining their phenotypes. Thus, the computation of such energy landscapes offers a sensitive way to estimate the impact of mutations. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Using vertebral movement and intact paraspinal muscles to determine the distribution of intrafusal fiber innervation of muscle spindle afferents in the anesthetized cat.

    PubMed

    Reed, William R; Cao, Dong-Yuan; Ge, Weiqing; Pickar, Joel G

    2013-03-01

    Increasing our knowledge regarding intrafusal fiber distribution and physiology of paraspinal proprioceptors may provide key insights regarding proprioceptive deficits in trunk control associated with low back pain and lead to more effective clinical intervention. The use of vertebral movement as a means to reliably stretch paraspinal muscles would greatly facilitate physiological study of paraspinal muscle proprioceptors where muscle tendon isolation is either very difficult or impossible. The effects of succinylcholine (SCh) on 194 muscle spindle afferents from lumbar longissimus or multifidus muscles in response to computer-controlled, ramp-and-hold movements of the L(6) vertebra were investigated in anesthetized cats. Paraspinal muscles were stretched by moving the L(6) vertebra 1.5-1.7 mm in the dorsal-ventral direction. Initial frequency (IF), dynamic difference (DD), their changes (∆) following SCh injection (100-400 μg kg(-1)), and post-SCh dynamic difference (SChDD) were measured. Muscle spindle intrafusal fiber terminations were classified as primary or secondary fibers as well as bag(1) (b(1)c), bag(2) (b(2)c), b(1)b(2)c, or chain (c) fibers. Intrafusal fiber subpopulations were distinguished using logarithmic transformation of SChDD and ∆IF distributions as established by previous investigators. Increases in DD indicate strength of b(1)c influence while increases in IF indicate strength of b(2)c influence. Out of 194 afferents, 46.9 % of afferents terminated on b(2)c fibers, 46.4 % on b(1)b(2)c fibers, 1 % on b(1)c fibers, and 5.7 % terminated on c fibers. Based on these intrafusal fiber subpopulation distributions, controlled vertebral movement can effectively substitute for direct tendon stretch and allow further investigation of paraspinal proprioceptors in this anatomically complex body region.

  9. Movement.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    Focuses on movement: movable art, relocating families, human rights, and trains and cars. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books, additional resources and activities (PEN)

  10. Effects of external calcium concentration and pH on charge movement in frog skeletal muscle.

    PubMed Central

    Shlevin, H H

    1979-01-01

    1. The effects of both external Ca2+ (1.8, 25, 50 and 100 mM) and external pH (pH 5.5, 7.15, and 9.0) on the voltage-dependence of charge movement in frog skeletal muscle were examined using the three intracellular micro-electrode voltage-clamp technique. 2. The two-state model of Schneider & Chandler (1973) was used to describe the voltage distribution of membrane charge. The parameters of this model are: Qmax, the maximum quantity of charge; V, the potential of equal distribution of charge; and k, a constant relating to the steepness of the charge vs. voltage relationship. 3. In 1.8 mM external Ca2+, alterations, in external pH shifted the transition potential, V, from a mean +/- S.E. of mean of -36.5 +/- 0.9 mV at pH 7.15 to -25.8 +/- 1.3 mV at pH 5.5 and to -42.5 +/- 1.8 mV at pH 9.0. These shifts are consistent with surface charge theory. No significant changes in Qmax or k were observed over the range of pH 5.5--9.0. 4. A reasonable fit of surface charge theory to the shifts in V over the range pH 5.5--9.0 could be obtained with surface charge densities and binding constants: sigma 1 = -1 e/165 A2, pK1 = 3.9 and sigma 2 = -1 e/400 A2, pK2 = 8. 5. However, at pH 7.15, both V and k changed with increasing external Ca2+ concentration. V shifted from -34.9 +/- 3.7 mV in 1.8 mM-Ca2+ to -13.8 +/- 5.1 mV, -19.3 +/- 3.6 mV and 3.3 +/- 9.3 mV in 25, 50 and 100 mM-Ca2+ respectively. k increased from 8.3 +/- 0.6 mV in 1.8 mM-Ca2+ to 15.3 +/- 1.4 mV, 14.6 +/- 1.6 mV and 20.0 +/- 2.9 mV in 25, 50 and 100 mM-Ca2+. Changes in k reflect decreases in the apparent charged particle valence from approximately 3 in 1.8 mM-Ca2+ to approximately 1.2 in 100 mM-Ca2+. As the external Ca2+ concentration was raised, Qmax was at least as large as that measured in 1.8 mM-Ca2+. The 43% decrease in the apparent valence of the charged groups cannot be explained by simple surface charge theory and may reflect a specific interaction between external Ca2+ and the charged groups. 6. Shifts in V

  11. The Movement- and Load-Dependent Differences in the EMG Patterns of the Human Arm Muscles during Two-Joint Movements (A Preliminary Study).

    PubMed

    Tomiak, Tomasz; Abramovych, Tetiana I; Gorkovenko, Andriy V; Vereshchaka, Inna V; Mishchenko, Viktor S; Dornowski, Marcin; Kostyukov, Alexander I

    2016-01-01

    Slow circular movements of the hand with a fixed wrist joint that were produced in a horizontal plane under visual guidance during conditions of action of the elastic load directed tangentially to the movement trajectory were studied. The positional dependencies of the averaged surface EMGs in the muscles of the elbow and shoulder joints were compared for four possible combinations in the directions of load and movements. The EMG intensities were largely correlated with the waves of the force moment computed for a corresponding joint in the framework of a simple geometrical model of the system: arm - experimental setup. At the same time, in some cases the averaged EMGs exit from the segments of the trajectory restricted by the force moment singular points (FMSPs), in which the moments exhibited altered signs. The EMG activities display clear differences for the eccentric and concentric zones of contraction that are separated by the joint angle singular points (JASPs), which present extreme at the joint angle traces. We assumed that the modeled patterns of FMSPs and JASPs may be applied for an analysis of the synergic interaction between the motor commands arriving at different muscles in arbitrary two-joint movements.

  12. The Movement- and Load-Dependent Differences in the EMG Patterns of the Human Arm Muscles during Two-Joint Movements (A Preliminary Study)

    PubMed Central

    Tomiak, Tomasz; Abramovych, Tetiana I.; Gorkovenko, Andriy V.; Vereshchaka, Inna V.; Mishchenko, Viktor S.; Dornowski, Marcin; Kostyukov, Alexander I.

    2016-01-01

    Slow circular movements of the hand with a fixed wrist joint that were produced in a horizontal plane under visual guidance during conditions of action of the elastic load directed tangentially to the movement trajectory were studied. The positional dependencies of the averaged surface EMGs in the muscles of the elbow and shoulder joints were compared for four possible combinations in the directions of load and movements. The EMG intensities were largely correlated with the waves of the force moment computed for a corresponding joint in the framework of a simple geometrical model of the system: arm - experimental setup. At the same time, in some cases the averaged EMGs exit from the segments of the trajectory restricted by the force moment singular points (FMSPs), in which the moments exhibited altered signs. The EMG activities display clear differences for the eccentric and concentric zones of contraction that are separated by the joint angle singular points (JASPs), which present extreme at the joint angle traces. We assumed that the modeled patterns of FMSPs and JASPs may be applied for an analysis of the synergic interaction between the motor commands arriving at different muscles in arbitrary two-joint movements. PMID:27375496

  13. Regulation of Animal Use: Voluntary and Involuntary.

    ERIC Educational Resources Information Center

    Clark, J. Derrell

    1979-01-01

    The regulation (voluntary and involuntary) of animal care and use throughout history in research and teaching is reviewed. The role of several organizations concerned with various aspects of animal quality, care, and use is discussed. (BH)

  14. Involuntariness in hypnotic responding and dissociative symptoms.

    PubMed

    Dell, Paul F

    2010-01-01

    Clark Hull's (1933) research on dissociation was based on a 'straw man' formulation of dissociation; he claimed that dissociation requires noninterference. Hull completely ignored the then-current paradigm of dissociation--dissociation as automatism--and claimed that he had refuted the validity of the phenomenon of dissociation. Hull's view of dissociation held sway in the hypnosis field for 60 years. This essay seeks to retrieve the Janetian paradigm of dissociation as automatism. Automatisms are unexpected, uninitiated, involuntary behaviors that just 'happen.' The author argues that human sensitivity to the experience of involuntariness (a) is quite important, (b) was selected by evolution, and (c) is central to both hypnotic responses and dissociative symptoms. This editorial urges the hypnosis field and the dissociation field to jointly undertake a renewed investigation of the experience of involuntariness and to follow recent neuroimaging studies which indicate that the parietal cortex underlies the experience of involuntariness.

  15. Contemplated Suicide Among Voluntary and Involuntary Retirees

    ERIC Educational Resources Information Center

    Peretti, Peter O.; Wilson, Cedric

    1978-01-01

    This study explored anomic and egoistic dimensions of contemplated suicide among voluntary and involuntary retired males. Results indicated a direct relationship between anomie and egoism on the one hand, and contemplation of suicide on the other. (Author)

  16. Contemplated Suicide Among Voluntary and Involuntary Retirees

    ERIC Educational Resources Information Center

    Peretti, Peter O.; Wilson, Cedric

    1978-01-01

    This study explored anomic and egoistic dimensions of contemplated suicide among voluntary and involuntary retired males. Results indicated a direct relationship between anomie and egoism on the one hand, and contemplation of suicide on the other. (Author)

  17. Magnitudes of gluteus medius muscle activation during standing hip joint movements in spiral-diagonal patterns using elastic tubing resistance.

    PubMed

    Youdas, James W; Adams, Kady E; Bertucci, John E; Brooks, Koel J; Steiner, Meghan M; Hollman, John H

    2015-01-01

    The aim of this study was to simultaneously quantify electromyographic (EMG) activation levels (% maximum voluntary isometric contraction [MVIC]) within the gluteus medius muscles on both moving and stance limbs across the performance of four proprioceptive neuromuscular facilitation (PNF) spiral-diagonal patterns in standing using resistance provided by elastic tubing. Differential EMG activity was recorded from the gluteus medius muscle of 26 healthy participants. EMG signals were collected with surface electrodes at a sampling frequency of 1000 Hz during three consecutive repetitions of each spiral-diagonal movement pattern. Significant differences existed among the four-spiral-diagonal movement patterns (F3,75 = 19.8; p < 0.001). The diagonal two flexion [D2F] pattern produced significantly more gluteus medius muscle recruitment (50 SD 29.3% MVIC) than any of the other three patterns and the diagonal one extension [D1E] (39 SD 37% MVIC) and diagonal two extension [D2E] (35 SD 29% MVIC) patterns generated more gluteus medius muscle recruitment than diagonal one flexion [D1F] (22 SD 21% MVIC). From a clinical efficiency standpoint, a fitness professional using the spiral-diagonal movement pattern of D2F and elastic tubing with an average peak tension of about 9% body mass may be able to concurrently strengthen the gluteus medius muscle on both stance and moving lower limbs.

  18. Novel Method for Predicting Dexterous Individual Finger Movements by Imaging Muscle Activity Using a Wearable Ultrasonic System.

    PubMed

    Sikdar, Siddhartha; Rangwala, Huzefa; Eastlake, Emily B; Hunt, Ira A; Nelson, Andrew J; Devanathan, Jayanth; Shin, Andrew; Pancrazio, Joseph J

    2014-01-01

    Recently there have been major advances in the electro-mechanical design of upper extremity prosthetics. However, the development of control strategies for such prosthetics has lagged significantly behind. Conventional noninvasive myoelectric control strategies rely on the amplitude of electromyography (EMG) signals from flexor and extensor muscles in the forearm. Surface EMG has limited specificity for deep contiguous muscles because of cross talk and cannot reliably differentiate between individual digit and joint motions. We present a novel ultrasound imaging based control strategy for upper arm prosthetics that can overcome many of the limitations of myoelectric control. Real time ultrasound images of the forearm muscles were obtained using a wearable mechanically scanned single element ultrasound system, and analyzed to create maps of muscle activity based on changes in the ultrasound echogenicity of the muscle during contraction. Individual digit movements were associated with unique maps of activity. These maps were correlated with previously acquired training data to classify individual digit movements. Preliminary results using ten healthy volunteers demonstrated this approach could provide robust classification of individual finger movements with 98% accuracy (precision 96%-100% and recall 97%-100% for individual finger flexions). The change in ultrasound echogenicity was found to be proportional to the digit flexion speed (R(2)=0.9), and thus our proposed strategy provided a proportional signal that can be used for fine control. We anticipate that ultrasound imaging based control strategies could be a significant improvement over conventional myoelectric control of prosthetics.

  19. Fatigue-Induced Changes in Movement Pattern and Muscle Activity During Ballet Releve on Demi-Pointe.

    PubMed

    Lin, Cheng-Feng; Lee, Wan-Chin; Chen, Yi-An; Hsue, Bih-Jen

    2016-08-01

    Fatigue in ballet dancers may lead to injury, particularly in the lower extremities. However, few studies have investigated the effects of fatigue on ballet dancers' performance and movement patterns. Thus, the current study examines the effect of fatigue on the balance, movement pattern, and muscle activities of the lower extremities in ballet dancers. Twenty healthy, female ballet dancers performed releve on demi-pointe before and after fatigue. The trajectory of the whole body movement and the muscle activities of the major lower extremity muscles were recorded continuously during task performance. The results show that fatigue increases the medial-lateral center of mass (COM) displacement and hip and trunk motion, but decreases the COM velocity and ankle motion. Moreover, fatigue reduces the activities of the hamstrings and tibialis anterior, but increases that of the soleus. Finally, greater proximal hip and trunk motions are applied to compensate for the effects of fatigue, leading to a greater COM movement. Overall, the present findings show that fatigue results in impaired movement control and may therefore increase the risk of dance injury.

  20. Intramembrane charge movement and sarcoplasmic calcium release in enzymatically isolated mammalian skeletal muscle fibres.

    PubMed Central

    Szentesi, P; Jacquemond, V; Kovács, L; Csernoch, L

    1997-01-01

    1. Single muscle fibres were dissociated enzymatically from the extensor digitorum longus and communis muscles of rats and guinea-pigs. The fibres were mounted into a double Vaseline gap experimental chamber and the events in excitation-contraction coupling were studied under voltage clamp conditions. 2. The voltage dependence of intramembrane charge movement followed a two-state Boltzmann distribution with maximal available charge of 26.1 +/- 1.5 and 26.1 +/- 1.3 nC microF-1, mid-point voltage of -35.1 +/- 5.0 and -42.2 +/- 1.2 mV and steepness of 16.7 +/- 2.2 and 17.0 +/- 1.9 mV (means +/- S.E.M., n = 7 and 4) in rats and guinea-pigs, respectively. 3. Intracellular calcium concentration ([Ca2+]i) was monitored using the calcium-sensitive dyes antipyrylazo III, fura-2 and mag-fura-5. Resting [Ca2+]i was similar in rats and guinea-pigs with 125 +/- 18 and 115 +/- 8 nM (n = 10 and 9), respectively, while the maximal increase for a 100 ms depolarization to 0 mV was larger in rats (6.3 +/- 1.0 microM; n = 7), than in guinea-pigs (2.8 +/- 0.3; n = 4). 4. The rate of calcium release (Rrel) from the sarcoplasmic reticulum (SR) displayed an early peak followed by a fast and a slow decline to a quasi maintained steady level. After normalizing Rrel to the estimated SR calcium content (1.2 +/- 0.1 and 0.9 +/- 0.1 mM in rats and guinea-pigs, respectively) and correcting for depletion of calcium in the SR the peak and steady levels at 0 mV, respectively, were found to be 2.50 +/- 0.08 and 0.81 +/- 0.06% ms-1 in rats and 2.43 +/- 0.25 and 0.88 +/- 0.01% ms-1 in guinea-pigs. The voltage dependence was essentially the same in both species, but different from that in amphibians. 5. These experiments show that enzymatic isolation yields functionally intact mammalian skeletal muscle fibres for Vaseline gap experiments. The data also suggest a close connection in the regulation of the different kinetic components of SR calcium release in mammalian skeletal muscle. PMID:9423180

  1. Targeted upper-limb Wii-based Movement Therapy also improves lower-limb muscle activation and functional movement in chronic stroke.

    PubMed

    Trinh, Terry; Shiner, Christine T; Thompson-Butel, Angelica G; McNulty, Penelope A

    2017-09-01

    Post-stroke hemiparesis may manifest as asymmetric gait, poor balance, and inefficient movement patterns. We investigated improvements in lower-limb muscle activation and function during Wii-based Movement Therapy (WMT), a rehabilitation program specifically targeting upper-limb motor-function. Electromyography (EMG) was recorded bilaterally from tibialis anterior (TA) in 20 stroke patients during a 14-day WMT program. EMG amplitude and burst duration were analyzed during stereotypical movement sequences of WMT activities. Functional movement ability was assessed pre- and post-therapy including 6-min walk test (6MWT), stair-climbing speed, and Wolf Motor Function Test timed-tasks. TA EMG burst duration during Wii-golf increased by 30% on the more-affected side (p = 0.04) and decreased by 28% on the less-affected side. Patients who did not step during Wii-tennis had a 16% decrease in more-affected TA burst sum (p = 0.047) resulting in more symmetrical activation ratio at late-therapy, with the ratio changing from 3.24 ± 2.25 to 0.99 ± 0.11 (p = 0.047). Six-minute walk and stair-climbing speed improved (p = 0.005 and 0.03, respectively), as did upper-limb movement (p ≤ 0.001). This study provides physiological evidence for lower-limb improvements with WMT. Different patterns of muscle activation changes were evident across the WMT activities. Despite the relatively good pre-therapy lower-limb function, muscle activation and symmetry improved significantly with upper-limb WMT. Implications for rehabilitation WMT is an upper-limb neurorehabilitation program that also improves lower-limb motor-function. We report a shift towards more symmetrical muscle activation of tibialis anterior on the more- and less-affected sides that were reflected in increased distance walked during the 6MWT. The use of standing during therapy not only improves lower-limb function but also permits larger and more powerful upper-limb movements. Targeted upper

  2. Contraction threshold and the "hump" component of charge movement in frog skeletal muscle

    PubMed Central

    1991-01-01

    The delayed component of intramembranous charge movement (hump, I gamma) was studied around the contraction threshold in cut skeletal muscle fibers of the frog (Rana esculenta) in a single Vaseline-gap voltage clamp. Charges (Q) were computed as 50-ms integrals of the ON (QON) and OFF (QOFF) of the asymmetric currents after subtracting a baseline. The hump appeared in parallel with an excess of QON over QOFF by approximately 2.5 nC/mu F. Caffeine (0.75 mM) not only shifted the contraction threshold but moved both the hump and the difference between the ON and OFF charges to more negative membrane potentials. When using 10-mV voltage steps on top of different prepulse levels, the delayed component, if present, was more readily observable. The voltage dependences of the ON and OFF charges measured with these pulses were clearly different: QON had a maximum at or slightly above the contraction threshold, while QOFF increased monotonically in the voltage range examined. Caffeine (0.75 mM) shifted this voltage dependence of QON toward more negative membrane potentials, while that of QOFF was hardly influenced. These results show that the delayed component of intramembranous charge movement either is much slower during the OFF than during the ON, or returns to the OFF position during the pulse. Tetracaine (25 microM) had similar effects on the charge movement currents, shifting the voltage dependence on the ON charge in parallel with the contraction threshold, but to more positive membrane potentials, and leaving QOFF essentially unchanged. The direct difference between the charge movement measured in the presence of caffeine and in control solution was either biphasic or resembled the component isolated by tetracaine, suggesting a common site of caffeine and tetracaine action. The results can be understood if the released Ca plays a direct role in the generation of the hump, as proposed in the first paper of this series (Csernoch et al. 1991. J. Gen. Physiol. 97

  3. Neural control of rhythmic human arm movement: phase dependence and task modulation of hoffmann reflexes in forearm muscles.

    PubMed

    Zehr, E Paul; Collins, David F; Frigon, Alain; Hoogenboom, Nienke

    2003-01-01

    Although we move our arms rhythmically during walking, running, and swimming, we know little about the neural control of such movements. Our working hypothesis is that neural mechanisms controlling rhythmic movements are similar in the human lumbar and cervical spinal cord. Thus reflex modulation during rhythmic arm movement should be similar to that seen during leg movement. Our main experimental hypotheses were that the amplitude of H-reflexes in the forearm muscles would be modulated during arm movement (i.e., phase-dependent) and would be inhibited during cycling compared with static contraction (i.e., task-dependent). Furthermore, to determine the locus of any modulation, we tested the effect that active and passive movement of the ipsilateral (relative to stimulated arm) and contralateral arm had on H-reflex amplitude. Subjects performed rhythmic arm cycling on a custom-made hydraulic ergometer in which the two arms could be constrained to move together (180 degrees out of phase) or could rotate independently. Position of the stimulated limb in the movement cycle is described with respect to the clock face. H-reflexes were evoked at 12, 3, 6, and 9 o'clock positions during static contraction as well as during rhythmic arm movements. Reflex amplitudes were compared between tasks at equal M wave amplitudes and similar levels of electromyographic (EMG) activity in the target muscle. Surface EMG recordings were obtained bilaterally from flexor carpi radialis as well as from other muscles controlling the wrist, elbow, and shoulder. Compared with reflexes evoked during static contractions, movement of the stimulated limb attenuated H-reflexes by 50.8% (P < 0.005), 65.3% (P < 0.001), and 52.6% (P < 0.001) for bilateral, active ipsilateral, and passive ipsilateral movements, respectively. In contrast, movement of the contralateral limb did not significantly alter H-reflex amplitude. H-reflexes were also modulated by limb position (P < 0.005). Thus task- and phase

  4. Anticipatory postural adjustments in arm muscles associated with movements of the contralateral limb and their possible role in interlimb coordination.

    PubMed

    Baldissera, Fausto; Rota, Viviana; Esposti, Roberto

    2008-02-01

    While sitting on a turnable stool, with both shoulders flexed at 90 degrees or, alternatively, with arms parallel to the trunk and the elbows flexed at 90 degrees--the hands being semisupine--subjects performed unidirectional and cyclic movements on the horizontal plane of the right arm (adduction-abduction) or hand (flexion-extension). The left arm was still, in a position symmetrical to that of the right limb and with the hand contacting a fixed support by the palmar or dorsal surface. During both unidirectional and cyclic arm or hand movements, activation of the prime mover muscles (right Pectoralis Major for arm adduction and Infraspinatus for abduction; right Flexor Carpi Radialis and Extensor Carpi Radialis for the hand movements) was accompanied by activation of the homologous muscles of the contralateral arm and inhibition of antagonists. The contralateral activities (1) regularly preceded the burst in the movement prime movers and (2) were organised in fixation chains that, exerting forces on the hand fixed support, will counterbalance the rotatory action exerted on the trunk by the primary movement. Based on these features, these activities may be classified as anticipatory postural adjustments (APAs). The observed APAs distribution is such as to favour the preferential (mirror symmetrical) coupling of upper limb movements on the horizontal plane. The possible role of these APAs in determining the different constraints experienced when performing mirror symmetrical versus isodirectional coupling is discussed.

  5. Mandibular movement and muscle activity during mastication in the guinea pig (Cavia porcellus).

    PubMed

    Byrd, K E

    1981-11-01

    Optoelectronic analysis of mandibular movement and electromyography (EMG) of masticatory muscles in Cavia porcellus indicate bilateral, unilateral, and gnawing cycles. During bilateral and unilateral cycles, the mandibular tip moves forward, lateral, and down during the lingual phase of the power stroke to bring the teeth into occlusion. EMG activity is generally asymmetric, with the exception of activity of the temporalis muscle during bilateral cycles. During gnawing cycles, the mandible moves in an anteroposterior direction that is opposite that during bilateral and unilateral chew cycles. Bilateral and unilateral cycles of pellets were significantly longer than carrot. With the exception of the width of bilateral cycles, the magnitude of cycle width, length, and height during the mastication of carrots was greater than that during the mastication of pellets. Significant differences exist between EMG durations during mastication of pellets and carrots. The lateral pterygoid displays continuous activity during gnawing cycles. Significant differences also exist in the duration of EMG activity between the working and balancing side during all three cycle types. High level of activity of balancing side temporalis and anterior belly of digastric (ABD) during bilateral cycles occurs during rotation and depression of the mandible during the power stroke. The temporalis apparently provides a "braking" or compensatory role during closing and power strokes. Differences between Cavia masticatory patterns and those shown by Rattus and Mesocricetus are apparently due to differences in dental morphology, occlusal relationships, and, possibly, the poorly developed temporalis in Cavia. The large number and wide diversity of rodent groups afford students of mammalian mastication an opportunity to investigate and compare different masticatory specializations.

  6. Semitendinosus snapping: analysis of movement, electromyographic activities, muscle strength and endurance, motor control and joint position sense

    PubMed Central

    Guney, Hande; Kaya, Defne; Yilgor, Caglar; Cilli, Murat; Aritan, Serdar; Yuksel, Inci; Doral, Mahmut Nedim

    2013-01-01

    Summary A female ballet with a history of two-years of semi-tendinosus (ST) snapping was assessed. On physical examination snapping was observed during hyperextension of the knee. Neither any history of trauma nor treatment was recalled. Magnetic resonance imaging (MRI), movement analysis, onset timing of ST and Bisceps Femoris (BF), motor control, isokinetic muscle strength and endurance, joint position sense (JPS) were assessed. The MRI findings were normal. There were abnormal oscillations observed during hyperextension of the snapping knee compared to healthy side. There were no isokinetic muscle strength nor do muscle endurance differences. The motor control and JPS deficits were greater on the snapping knee than the healthy side. ST onset timing was earlier than BF on the snapping side. Snapping of the semitendinosus tendon has an adverse affect on JPS, motor control and onset timing of the knee muscles. PMID:24367776

  7. The impact of this involuntary mass "return" to Jordan in the wake of the Gulf crisis.

    PubMed

    Van Hear, N

    1995-01-01

    "This article investigates the impact of the involuntary movement to Jordan of about 300,000 Palestinians in the wake of the Gulf crisis of 1990-91. It explores the character of the population that arrived en masse in Jordan and whether their arrival burdened or benefitted that country.... The involuntary migration compounded other effects of the Gulf crisis on Jordan and exacerbated the country's already serious economic problems. Integration of the returnees was painful. But contrary to initial expectations, the mass arrival did not result in unmitigated disaster and may have contributed to an economic recovery in Jordan, suggesting that there may be potentially beneficial windfall effects of sudden population influxes, even when they are involuntary and disorderly."

  8. Involuntary hand levitation associated with parietal damage: another alien hand syndrome.

    PubMed

    Carrilho, P E; Caramelli, P; Cardoso, F; Barbosa, E R; Buchpiguel, C A; Nitrini, R

    2001-09-01

    The alien hand syndrome (AHS) usually consists of an autonomous motor activity perceived as an involuntary and purposeful movement, with a feeling of foreignness of the involved limb, commonly associated with a failure to recognise ownership of the limb in the absence of visual clues. It has been described in association to lesions of the frontal lobes and corpus callosum. However, parietal damage can promote an involuntary, but purposeless, hand levitation, which, sometimes, resembles AHS. In the present study, four patients (cortico-basal ganglionic degeneration - n=2; Alzheimer's disease - n=1 and parietal stroke - n=1) who developed alien hand motor behaviour and whose CT, MRI and/or SPECT have disclosed a major contralateral parietal damage or dysfunction are described. These results reinforce the idea that parietal lobe lesions may also play a role in some patients with purposeless involuntary limb levitation, which is different from the classic forms of AHS.

  9. Effects of different movement directions on electromyography recorded from the shoulder muscles while passing the target positions.

    PubMed

    Sakaki, Yoshinari; Kaneko, Fuminari; Watanabe, Kota; Kobayashi, Takuma; Katayose, Masaki; Aoki, Nobuhiro; Shibata, Eriko; Yamashita, Toshihiko

    2013-12-01

    We compared electromyography (EMG) recorded from the shoulder joint muscles in the same position for different movement directions. Fifteen healthy subjects participated. They performed shoulder elevation from 0° to 120°, shoulder depression from 120° to 0°, shoulder horizontal adduction from -15° to 105°, and shoulder horizontal abduction from 105° to -15°. The target positions were 90° shoulder elevation in the 0°, 30°, 60°, and 90° planes (0°, 30°, 60°, and 90° positions). EMG signals were recorded from the supraspinatus (SSP) muscle by fine-wire electrodes. EMG signals from the infraspinatus (ISP), anterior deltoid, middle deltoid, and posterior deltoid muscles were recorded using active surface electrodes. During elevation and horizontal abduction, the SSP showed significantly higher activity than that shown during depression and during horizontal adduction in the 0°, 30°, and 60° positions. During elevation, the ISP showed significantly higher activity than during depression and during horizontal adduction in the 90° position. During horizontal abduction, the ISP showed significantly higher activity than during depression in the 90° position. When the movement tasks were performed in different movement directions at the same speed, each muscle showed characteristic activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Effect of very low-intensity resistance training with slow movement on muscle size and strength in healthy older adults.

    PubMed

    Watanabe, Yuya; Madarame, Haruhiko; Ogasawara, Riki; Nakazato, Koichi; Ishii, Naokata

    2014-11-01

    We previously reported that low-intensity [50% of one repetition maximum (1RM)] resistance training with slow movement and tonic force generation (LST) causes muscle hypertrophy and strength gain in older participants. The aim of this study was to determine whether resistance training with slow movement and much more reduced intensity (30%1RM) increases muscle size and strength in older adults. Eighteen participants (60-77 years) were randomly assigned to two groups. One group performed very low-intensity (30% 1RM) knee extension exercise with continuous muscle contraction (LST: 3-s eccentric, 3-s concentric, and 1-s isometric actions with no rest between each repetition) twice a week for 12 weeks. The other group underwent intermitted muscle contraction (CON: 1-s concentric and 1-s eccentric actions with 1-s rest between each repetition) for the same time period. The 1RM, isometric and isokinetic strengths, and cross-sectional image of the mid-thigh obtained by magnetic resonance imaging were examined before and after the intervention. LST significantly increased the cross-sectional area of the quadriceps muscle (5.0%, P<0.001) and isometric and isokinetic knee extension strengths (P<0.05). CON failed to increase muscle size (1.1%, P = 0.12), but significantly improved its strength (P<0.05). These results indicate that even if the intensity is as low as 30% 1RM, LST can increase muscle size and strength in healthy older adults. The large total contraction time may be related to muscle hypertrophy and strength gain. LST would be useful for preventing sarcopenia in older individuals.

  11. Movement disorders and sleep.

    PubMed

    Driver-Dunckley, Erika D; Adler, Charles H

    2012-11-01

    This article summarizes what is currently known about sleep disturbances in several movement disorders including Parkinson disease, essential tremor, parkinsonism, dystonia, Huntington disease, myoclonus, and ataxias. There is an association between movement disorders and sleep. In some cases the prevalence of sleep disorders is much higher in patients with movement disorder, such as rapid eye movement sleep behavior disorder in Parkinson disease. In other cases, sleep difficulties worsen the involuntary movements. In many cases the medications used to treat patients with movement disorder disturb sleep or cause daytime sleepiness. The importance of discussing sleep issues in patients with movement disorders cannot be underestimated.

  12. Caffeine enhances intramembranous charge movement in frog skeletal muscle by increasing cytoplasmic Ca2+ concentration.

    PubMed Central

    Shirokova, N; Ríos, E

    1996-01-01

    1. Currents of intramembranous charge movement were recorded, together with intracellular [Ca2+], in single muscle fibres subjected to voltage-clamp depolarization and 'pulses' of extracellular solution with a Ca2+ release-inducing concentration of caffeine (10 mM). 2. When caffeine was present prior to and during the voltage pulses, the charge transferred by pulses to between -60 and -40 mV increased by about 40%. 3. In fibres depleted of Ca2+ in the sarcoplasmic reticulum (SR), caffeine had no effect on charge transfer or kinetics. 4. Whenever the prior exposure to caffeine resulted in a large elevation in [Ca2+]i at the start of the depolarizing pulse, there was an increase in I beta, the monotonically decaying component of charge movement. When the presence of caffeine enhanced Ca2+ release induced by the pulse, there was increase in I gamma, the hump-like component. 5. The charge transferred during a pulse to -50 mV increased with time of exposure to caffeine. Ca2+ release induced by the voltage pulse grew during the first second of caffeine exposure, then decreased with longer exposure time. The enhancement of charge transfer by caffeine was therefore not due to the increase in Ca2+ release caused by the drug. 6. The increase in charge transfer was a uniform, monotonically increasing function of the [Ca2+]i attained at the end of the voltage pulse. 7. Charge transfer, as a function of [Ca2+]i, pulse voltage and time, was simulated with a model, used previously, in which Ca2+ binds to intracellular sites and increases the electrical potential near the voltage sensors. Two sites were needed to fit the observations, with dissociation constants of 60 nM and 2 to 10 microM. 8. In the presence of caffeine, the voltage-driven movement of a given amount of intra-membranous charge resulted in greater activation of release permeability. 9. All effects of caffeine observed in this and the preceding paper could be explained assuming a single action: caffeine increases

  13. The effect of motor imagery training for trunk movements on trunk muscle control and proprioception in stroke patients.

    PubMed

    Oh, Dong-Sik; Choi, Jong-Duk

    2017-07-01

    [Purpose] The present study was conducted to evaluate the effect of motor imagery training for trunk movements on trunk muscle control and proprioception in stroke patients. [Subjects and Methods] A total of 12 study subjects were randomly assigned to the experimental group (a motor imagery training group) and the control group (a neurodevelopmental treatment, NDT) group. The two groups were treated five times (30 minutes each time) per week for 4 weeks. The experimental group underwent imagery training for 10 minutes and trunk control centered NDT for 20 minutes and the control group underwent only trunk control centered NDT for 30 minutes. The trunk muscle activity and the position sense of the subjects were evaluated before and after the intervention. [Results] The two groups showed significant improvements in muscle activity after the intervention. Only the experimental group showed significant improvements in proprioception. The experimental group showed significant improvements in the variations of muscle activity and proprioception compared to the control group. [Conclusion] Motor imagery training for trunk movements can be effectively used to improve trunk muscle activity and proprioception in stroke patients.

  14. An improved method to determine neuromuscular properties using force laws - From single muscle to applications in human movements.

    PubMed

    Siebert, T; Sust, M; Thaller, S; Tilp, M; Wagner, H

    2007-04-01

    We evaluate an improved method for individually determining neuromuscular properties in vivo. The method is based on Hill's equation used as a force law combined with Newton's equation of motion. To ensure the range of validity of Hill's equation, we first perform detailed investigations on in vitro single muscles. The force-velocity relation determined with the model coincides well with results obtained by standard methods (r=.99) above 20% of the isometric force. In addition, the model-predicted force curves during work loop contractions very well agree with measurements (mean difference: 2-3%). Subsequently, we deduce theoretically under which conditions it is possible to combine several muscles of the human body to model muscles. This leads to a model equation for human leg extension movements containing parameters for the muscle properties and for the activation. To numerically determine these invariant neuromuscular properties we devise an experimental method based on concentric and isometric leg extensions. With this method we determine individual muscle parameters from experiments such that the simulated curves agree well with experiments (r=.99). A reliability test with 12 participants revealed correlations r=.72-.91 for the neuromuscular parameters (p<.01). Predictions of similar movements under different conditions show mean errors of about 5%. In addition, we present applications in sports practise and theory.

  15. Ryanodine interferes with charge movement repriming in amphibian skeletal muscle fibers.

    PubMed Central

    Gonzalez, A; Caputo, C

    1996-01-01

    Cut twitch muscle fibers mounted in a triple Vaseline-gap chamber were used to study the effects of ryanodine on intramembranous charge movement, and in particular on the repriming of charge 1. Charge 1 repriming was measured either under steady-state conditions or by using a pulse protocol designed to study the time course of repriming. This protocol consisted of repolarizing the fibers to -100 mV from a holding potential of 0 mV, and then measuring the reprimed charge moving in the potential range between -40 and +20 mV. Ryanodine at a high concentration (100 microM) did not affect the maximum amount of movable charge 1 and charge 2, or their voltage dependence. This indicates that the alkaloid does not interact with the voltage sensor molecules. However, ryanodine did reduce the amount of reprimed charge 1 by approximately 60% suggesting the possibility of a retrograde interaction between ryanodine receptors and voltage sensors. PMID:8770214

  16. Computer-Based Algorithmic Determination of Muscle Movement Onset Using M-Mode Ultrasonography

    DTIC Science & Technology

    2017-04-01

    Pengel LH, Herbert RD, Gandevia SC. Measurement of muscle contraction with ultrasound imaging. Muscle Nerve 2003; 27:682–692. Hortobagyi T, Solnik S...discus- sion 56–67. Pulkovski N, Schenk P, Maffiuletti NA, Mannion AF. Tissue Doppler imaging for detecting onset of muscle activity. Muscle Nerve ...onset in the lumbar multifidus muscle recorded simultaneously by ultrasound imaging and intramuscular electromyography. Clin Biomech (Bris- tol, Avon

  17. The architectural design of the gluteal muscle group: implications for movement and rehabilitation.

    PubMed

    Ward, Samuel R; Winters, Taylor M; Blemker, Silvia S

    2010-02-01

    The organization of fibers within a muscle (architecture) defines the performance capacity of that muscle. In the current commentary, basic architectural terms are reviewed in the context of the major hip muscles and then specific illustrative examples relevant to lower extremity rehabilitation are presented. These data demonstrate the architectural and functional specialization of the hip muscles, and highlight the importance of muscle physiology and joint mechanics when evaluating and treating musculoskeletal disorders.

  18. Further Clinical Delineation of the MEF2C Haploinsufficiency Syndrome: Report on New Cases and Literature Review of Severe Neurodevelopmental Disorders Presenting with Seizures, Absent Speech, and Involuntary Movements.

    PubMed

    Vrečar, Irena; Innes, Josie; Jones, Elizabeth A; Kingston, Helen; Reardon, William; Kerr, Bronwyn; Clayton-Smith, Jill; Douzgou, Sofia

    2017-09-01

    Mutations in the MEF2C ( myocyte enhancer factor 2 ) gene have been established as a cause for an intellectual disability syndrome presenting with seizures, absence of speech, stereotypic movements, hypotonia, and limited ambulation. Phenotypic overlap with Rett's and Angelman's syndromes has been noted. Following the first reports of 5q14.3q15 microdeletions encompassing the MEF2C gene, further cases with point mutations and partial gene deletions of the MEF2C gene have been described. We present the clinical phenotype of our cohort of six patients with MEF2C mutations and compare our findings with previously reported patients as well as with a growing number of genetic conditions presenting with a severe neurodevelopmental, Rett-like, phenotype. We aim to add to the current knowledge of the natural history of the "MEF2C haploinsufficiency syndrome" as well as of the differential diagnosis, clinical management, and genetic counseling in this diagnostically challenging group of patients.

  19. Noradrenergic modulation of masseter muscle activity during natural rapid eye movement sleep requires glutamatergic signalling at the trigeminal motor nucleus.

    PubMed

    Schwarz, Peter B; Mir, Saba; Peever, John H

    2014-08-15

    Noradrenergic neurotransmission in the brainstem is closely coupled to changes in muscle activity across the sleep-wake cycle, and noradrenaline is considered to be a key excitatory neuromodulator that reinforces the arousal-related stimulus on motoneurons to drive movement. However, it is unknown if α-1 noradrenoceptor activation increases motoneuron responsiveness to excitatory glutamate (AMPA) receptor-mediated inputs during natural behaviour. We studied the effects of noradrenaline on AMPA receptor-mediated motor activity at the motoneuron level in freely behaving rats, particularly during rapid eye movement (REM) sleep, a period during which both AMPA receptor-triggered muscle twitches and periods of muscle quiescence in which AMPA drive is silent are exhibited. Male rats were subjected to electromyography and electroencephalography recording to monitor sleep and waking behaviour. The implantation of a cannula into the trigeminal motor nucleus of the brainstem allowed us to perfuse noradrenergic and glutamatergic drugs by reverse microdialysis, and thus to use masseter muscle activity as an index of motoneuronal output. We found that endogenous excitation of both α-1 noradrenoceptor and AMPA receptors during waking are coupled to motor activity; however, REM sleep exhibits an absence of endogenous α-1 noradrenoceptor activity. Importantly, exogenous α-1 noradrenoceptor stimulation cannot reverse the muscle twitch suppression induced by AMPA receptor blockade and nor can it elevate muscle activity during quiet REM, a phase when endogenous AMPA receptor activity is subthreshold. We conclude that the presence of an endogenous glutamatergic drive is necessary for noradrenaline to trigger muscle activity at the level of the motoneuron in an animal behaving naturally.

  20. Effect of sarcoplasmic reticulum calcium depletion on intramembranous charge movement in frog cut muscle fibers

    PubMed Central

    1995-01-01

    Cut muscle fibers from Rana temporaria (sarcomere length, 3.3-3.5 microns; temperature, 13-16 degrees C) were mounted in a double Vaseline-gap chamber and equilibrated for at least an hour with an internal solution that contained 20 mM EGTA and phenol red and an external solution that contained predominantly TEA-gluconate; both solutions were nominally Ca-free. The increase in total myoplasmic concentration of Ca (delta[CaT]) produced by sarcoplasmic reticulum (SR) Ca release was estimated from the change in pH produced when the released Ca was complexed by EGTA (Pape, P.C., D.-S. Jong, and W.K. Chandler. 1995. Journal of General Physiology. 106:259-336). The resting value of SR Ca content, [CaSR]R (expressed as myoplasmic concentration), was taken to be equal to the value of delta[CaT] obtained during a step depolarization (usually to -50 to -40 mV) that was sufficiently long (200-750 ms) to release all of the readily releasable Ca from the SR. In ten fibers, the first depolarization gave [CaSR]R = 839-1,698 microM. Progressively smaller values were obtained with subsequent depolarizations until, after 30-40 depolarizations, the value of [CaSR]R had usually been reduced to < 10 microM. Measurements of intramembranous charge movement, Icm, showed that, as the value of [CaSR]R decreased, ON-OFF charge equality held and the amount of charge moved remained constant. ON Icm showed brief initial I beta components and prominent I gamma "humps", even after the value of [CaSR]R was < 10 microM. Although the amplitude of the hump component decreased during depletion, its duration increased in a manner that preserved the constancy of ON charge. In the depleted state, charge movement was steeply voltage dependent, with a mean value of 7.2 mV for the Boltzmann factor k. These and other results are not consistent with the idea that there is one type of charge, Q beta, and that I gamma is a movement of Q beta caused by SR Ca release, as proposed by Pizarro, Csernoch, Uribe

  1. Problem: Thirst, Drinking Behavior, and Involuntary Dehydration

    NASA Technical Reports Server (NTRS)

    Greenleaf, John E.

    1992-01-01

    The phenomenon of involuntary dehydration, the delay in full restoration of a body water deficit by drinking, has been described extensively but relatively little is known about its physiological mechanism. It occurs primarily in humans when they are exposed to various stresses including exercise, environmental heat and cold, altitude, water immersion, dehydration, and perhaps microgravity, singly and in various combinations. The level of involuntary dehydration is approximately proportional to the degree of total stress imposed on the body. Involuntary dehydration appears to be controlled by more than one factor including social customs that influence what is consumed, the capacity and rate of fluid absorption from the gastrointestinal system, the level of cellular hydration involving the osmotic-vasopressin interaction with sensitive cells or structures in the central nervous system, and, to a lesser extent, hypovolemic-angiotensin II stimuli. Since humans drink when there is no apparent physiological stimulus, the psychological component should always be considered when investigating the total mechanisms for drinking.

  2. Problem: Thirst, Drinking Behavior, and Involuntary Dehydration

    NASA Technical Reports Server (NTRS)

    Greenleaf, John E.

    1992-01-01

    The phenomenon of involuntary dehydration, the delay in full restoration of a body water deficit by drinking, has been described extensively but relatively little is known about its physiological mechanism. It occurs primarily in humans when they are exposed to various stresses including exercise, environmental heat and cold, altitude, water immersion, dehydration, and perhaps microgravity, singly and in various combinations. The level of involuntary dehydration is approximately proportional to the degree of total stress imposed on the body. Involuntary dehydration appears to be controlled by more than one factor including social customs that influence what is consumed, the capacity and rate of fluid absorption from the gastrointestinal system, the level of cellular hydration involving the osmotic-vasopressin interaction with sensitive cells or structures in the central nervous system, and, to a lesser extent, hypovolemic-angiotensin II stimuli. Since humans drink when there is no apparent physiological stimulus, the psychological component should always be considered when investigating the total mechanisms for drinking.

  3. An Objective Functional Characterisation of Head Movement Impairment in Individuals with Neck Muscle Weakness Due to Amyotrophic Lateral Sclerosis

    PubMed Central

    Pancani, Silvia; Tindale, Wendy; Shaw, Pamela J.

    2017-01-01

    Background Neck muscle weakness and head drop are well recognised in patients with Amyotrophic lateral sclerosis (ALS), but an objective characterisation of the consequent head movement impairment is lacking. The aim of this study was to quantitatively characterise head movements in ALS compared to aged matched controls. Methods We evaluated two groups, one of thirteen patients with ALS and one of thirteen age-matched controls, during the execution of a series of controlled head movements, performed while wearing two inertial sensors attached on the forehead and sternum, respectively. We quantified the differences between the two groups from the sensor data using indices of velocity, smoothness and movement coupling (intended as a measure of undesired out of plane movements). Findings Results confirmed a general limitation in the ability of the ALS patients to perform and control head movements. High inter-patient variability was observed due to a wide range of observed functional impairment levels. The ability to extend the head backward and flex it laterally were the most compromised, with significantly lower angular velocity (P < 0.05, Cohen’s d > 0.8), reduced smoothness and greater presence of coupled movements with respect to the controls. A significant reduction of angular velocity (P < 0.05, Cohen’s d > 0.8) in extension, axial rotation and lateral flexion was observed when patients were asked to perform the movements as fast as possible. Interpretation This pilot study is the first study providing a functional objective quantification of head movements in ALS. Further work involving different body areas and correlation with existing methods of evaluating neuromuscular function, such as dynamometry and EMG, is needed to explore the use of this approach as a marker of disease progression in ALS. PMID:28068376

  4. The integrin-adhesome is required to maintain muscle structure, mitochondrial ATP production, and movement forces in Caenorhabditis elegans.

    PubMed

    Etheridge, Timothy; Rahman, Mizanur; Gaffney, Christopher J; Shaw, Debra; Shephard, Freya; Magudia, Jignesh; Solomon, Deepak E; Milne, Thomas; Blawzdziewicz, Jerzy; Constantin-Teodosiu, Dumitru; Greenhaff, Paul L; Vanapalli, Siva A; Szewczyk, Nathaniel J

    2015-04-01

    The integrin-adhesome network, which contains >150 proteins, is mechano-transducing and located at discreet positions along the cell-cell and cell-extracellular matrix interface. A small subset of the integrin-adhesome is known to maintain normal muscle morphology. However, the importance of the entire adhesome for muscle structure and function is unknown. We used RNA interference to knock down 113 putative Caenorhabditis elegans homologs constituting most of the mammalian adhesome and 48 proteins known to localize to attachment sites in C. elegans muscle. In both cases, we found >90% of components were required for normal muscle mitochondrial structure and/or proteostasis vs. empty vector controls. Approximately half of these, mainly proteins that physically interact with each other, were also required for normal sarcomere and/or adhesome structure. Next we confirmed that the dystrophy observed in adhesome mutants associates with impaired maximal mitochondrial ATP production (P < 0.01), as well as reduced probability distribution of muscle movement forces compared with wild-type animals. Our results show that the integrin-adhesome network as a whole is required for maintaining both muscle structure and function and extend the current understanding of the full complexities of the functional adhesome in vivo. © The Author(s).

  5. Muscle activity and head kinematics in unconstrained movements in subjects with chronic neck pain; cervical motor dysfunction or low exertion motor output?

    PubMed Central

    2013-01-01

    Background Chronic neck pain after whiplash associated disorders (WAD) may lead to reduced displacement and peak velocity of neck movements. Dynamic neck movements in people with chronic WAD are also reported to display altered movement patterns such as increased irregularity, which is suggested to signify impaired motor control. As movement irregularity is strongly related to the velocity and displacement of movement, we wanted to examine whether the increased irregularity in chronic WAD could be accounted for by these factors. Methods Head movements were completed in four directions in the sagittal plane at three speeds; slow (S), preferred (P) and maximum (M) in 15 men and women with chronic WAD and 15 healthy, sex and age-matched control participants. Head kinematics and measures of movement smoothness and symmetry were calculated from position data. Surface electromyography (EMG) was recorded bilaterally from the sternocleidomastoid and splenius muscles and the root mean square (rms) EMG amplitude for the accelerative and decelerative phases of movement were analyzed. Results The groups differed significantly with regard to movement velocity, acceleration, displacement, smoothness and rmsEMG amplitude in agonist and antagonist muscles for a series of comparisons across the test conditions (range 17 – 121%, all p-values < 0.05). The group differences in peak movement velocity and acceleration persisted after controlling for movement displacement. Controlling for differences between the groups in displacement and velocity abolished the difference in measures of movement smoothness and rmsEMG amplitude. Conclusions Simple, unconstrained head movements in participants with chronic WAD are accomplished with reduced velocity and displacement, but with normal muscle activation levels and movement patterns for a given velocity and displacement. We suggest that while reductions in movement velocity and displacement are robust changes and may be of clinical

  6. Movement - uncoordinated

    MedlinePlus

    ... Loss of coordination; Coordination impairment; Ataxia; Clumsiness; Uncoordinated movement ... Smooth graceful movement requires a balance between different muscle groups. A part of the brain called the cerebellum manages this balance.

  7. Increased muscle size and strength from slow-movement, low-intensity resistance exercise and tonic force generation.

    PubMed

    Watanabe, Yuya; Tanimoto, Michiya; Ohgane, Akane; Sanada, Kiyoshi; Miyachi, Motohiko; Ishii, Naokata

    2013-01-01

    The authors investigated the effects of low-intensity resistance training on muscle size and strength in older men and women. Thirty-five participants (age 59-76 yr) were randomly assigned to 2 groups and performed low-intensity (50% of 1-repetition maximum) knee-extension and -flexion exercises with either slow movement and tonic force generation (LST; 3-s eccentric, 3-s concentric, and 1-s isometric actions with no rest between repetitions) or normal speed (LN; 1-s concentric and 1-s eccentric actions with 1-s rests between repetitions) twice a week for 12 wk (2-wk preparation and 10-wk intervention). The LST significantly increased thigh-muscle thickness, as well as isometric knee-extension and -flexion strength. The LN significantly improved strength, but its hypertrophic effect was limited. These results indicate that even for older individuals, the LST can be an effective method for gaining muscle mass and strength.

  8. Center of Pressure Displacement of Standing Posture during Rapid Movements Is Reorganised Due to Experimental Lower Extremity Muscle Pain

    PubMed Central

    Shiozawa, Shinichiro; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

    2015-01-01

    Background Postural control during rapid movements may be impaired due to musculoskeletal pain. The purpose of this study was to investigate the effect of experimental knee-related muscle pain on the center of pressure (CoP) displacement in a reaction time task condition. Methods Nine healthy males performed two reaction time tasks (dominant side shoulder flexion and bilateral heel lift) before, during, and after experimental pain induced in the dominant side vastus medialis or the tibialis anterior muscles by hypertonic saline injections. The CoP displacement was extracted from the ipsilateral and contralateral side by two force plates and the net CoP displacement was calculated. Results Compared with non-painful sessions, tibialis anterior muscle pain during the peak and peak-to-peak displacement for the CoP during anticipatory postural adjustments (APAs) of the shoulder task reduced the peak-to-peak displacement of the net CoP in the medial-lateral direction (P<0.05). Tibialis anterior and vastus medialis muscle pain during shoulder flexion task reduced the anterior-posterior peak-to-peak displacement in the ipsilateral side (P<0.05). Conclusions The central nervous system in healthy individuals was sufficiently robust in maintaining the APA characteristics during pain, although the displacement of net and ipsilateral CoP in the medial-lateral and anterior-posterior directions during unilateral fast shoulder movement was altered. PMID:26680777

  9. Involuntary Rotations of a Steering Device Induced by Voluntary Rotations of the Head and Maintained Eccentric Head Positions.

    PubMed

    Heuer, Herbert; Klein, Wolfhard

    1999-09-01

    In a series of 4 experiments, the authors examined involuntary rotations of a steering device (handlebar or wheel) that were associated with periodic head rotations and eccentric head positions. Periodic head rotations resulted in isodirectional involuntary rotations of a horizontally arranged steering device of very small amplitude. When the orientation of a steering wheel was changed to vertical and to a backward tilt, the involuntary rotations were in the opposite direction. That pattern of results is consistent with the assumption that small movements of the shoulder girdle, which are associated with head turns and which cannot be prevented by mechanical immobilization of the shoulder, are propagated to the wheel, but is not consistent with previous suggestions that involuntary rotations of a steering device can result from the action of the tonic neck reflex. Effects that correspond to the pattern of the tonic neck reflex were found only when a spring-centered handlebar was held in an eccentric position; maintenance of the eccentric position was facilitated when the participant's head was turned in the opposite direction. The findings strongly suggest that head movements can result in involuntary movements of a steering device via different mechanisms.

  10. Excitability changes in human corticospinal projections to forearm muscles during voluntary movement of ipsilateral foot.

    PubMed

    Baldissera, Fausto; Borroni, Paola; Cavallari, Paolo; Cerri, Gabriella

    2002-03-15

    Excitability of the H-reflex in the relaxed flexor carpi radialis (FCR) muscle was tested during voluntary oscillations of the ipsilateral foot at five evenly spaced delays during a 600 ms cycle. In some experiments the H-reflex was conditioned by transcranial magnetic stimulation (TMS). With the hand prone, the amplitude of the FCR H-reflex was modulated sinusoidally with the same period as the foot oscillation, the modulation peak occurring in coincidence with contraction of the foot plantar-flexor soleus and the trough during contraction of the extensor tibialis anterior. When the H-reflex was facilitated by TMS at short latency (conditioning-test interval: -2 to -3.5 ms), the modulation was larger than that occurring with an unconditioned reflex of comparable size. This suggests that both the peripheral and the corticospinal components of the facilitated response were modulated in parallel. When the H-reflex was tested 40-60 ms after conditioning, i.e. during the cortical "silent period" induced by TMS, no direct effect was produced on the reflex size but the foot-associated modulation was deeply depressed. These results suggest that the reflex modulation may depend on activity fluctuations in the cortical motor area innervating the forearm motoneurones. It is proposed that when the foot is rhythmically oscillated, along with the full activation of the foot cortical area a simultaneous lesser co-activation of the forearm area produces a subliminal cyclic modulation of cervical motoneurones excitability. Should the two limbs be moved together, the time course of this modulation would favour isodirectional movements of the prone hand and foot, indeed the preferential coupling observed when hand and foot are voluntarily oscillated.

  11. Changes in neck and upper trunk muscle activities according to the angle of movement of the neck in subjects with forward head posture

    PubMed Central

    Cheon, SongHee; Park, SoHyun

    2017-01-01

    [Purpose] This study investigated changes in neck and upper trunk muscle activities according to the angle of movement of the neck in subjects with Forward Head Posture. [Subjects and Methods] Twenty subjects with forward head postures were recruited. The activities of the sternocleidomastoid muscle, splenius capitis and splenius cervicis muscles, upper trapezius muscle, and middle trapezius muscle during flexion and extension were assessed. [Results] The activity of the sternocleidomastoid muscle showed significant differences between the 30° flexed position and the full range of motion position, and between the neutral position and the full ROM position. The activity of the middle trapezius muscle showed a significant reduction in the 30° extended position and the full ROM position as compared to the neutral position. [Conclusion] In the full flexed position, sternocleidomastoid muscle activity increased significantly, and during extension position, the middle trapezius muscle reduced its activities. PMID:28265137

  12. Changes in neck and upper trunk muscle activities according to the angle of movement of the neck in subjects with forward head posture.

    PubMed

    Cheon, SongHee; Park, SoHyun

    2017-02-01

    [Purpose] This study investigated changes in neck and upper trunk muscle activities according to the angle of movement of the neck in subjects with Forward Head Posture. [Subjects and Methods] Twenty subjects with forward head postures were recruited. The activities of the sternocleidomastoid muscle, splenius capitis and splenius cervicis muscles, upper trapezius muscle, and middle trapezius muscle during flexion and extension were assessed. [Results] The activity of the sternocleidomastoid muscle showed significant differences between the 30° flexed position and the full range of motion position, and between the neutral position and the full ROM position. The activity of the middle trapezius muscle showed a significant reduction in the 30° extended position and the full ROM position as compared to the neutral position. [Conclusion] In the full flexed position, sternocleidomastoid muscle activity increased significantly, and during extension position, the middle trapezius muscle reduced its activities.

  13. EMG activities of two heads of the human lateral pterygoid muscle in relation to mandibular condyle movement and biting force.

    PubMed

    Hiraba, K; Hibino, K; Hiranuma, K; Negoro, T

    2000-04-01

    Electromyographic (EMG) activities of the superior (SUP) and inferior heads (INF) of the lateral pterygoid muscle (LPT) were recorded in humans during voluntary stepwise changes in biting force and jaw position that were adopted to exclude the effects of acceleration and velocity of jaw movements on the muscle activity. The SUP behaved like a jaw-closing muscle and showed characteristic activity in relation to the biting force. It showed a considerable amount of background activity (5-32% of the maximum) even in the intercuspal position without teeth clenching and reached a nearly maximum activity at relatively lower biting-force levels than the jaw-closing muscles during increment of the biting force. Stretch reflexes were found in the SUP, the function of which could be to stabilize the condyle against the biting force that pulls the condyle posteriorly. This notion was verified by examining the biomechanics on the temporomandibular joint. The complex movements of the mandibular condyle in a sagittal plane were decomposed into displacement in the anteroposterior direction (Ac) and angle of rotation (RAc) around a kinesiological specific point on the condyle. In relation to Ac, each head of the LPT showed quite a similar behavior to each other in all types of jaw movements across all subjects. Working ranges of the muscle activities were almost constant (Ac <3 mm for the SUP and Ac >3 mm for the INF). The amount of EMG activity of the SUP changed in inverse proportion to Ac showing a hyperbola-like relation, whereas that of the INF changed rather linearly. The EMG amplitude of the SUP showed a quasilinear inverse relation with RAc in the hinge movement during which the condyle rotated with no movement in the anteroposterior direction. This finding suggests that the SUP controls the angular relationship between the articular disk and the condyle. On the other hand, the position of the disk in relation to the maxilla, not to the condyle, is controlled indirectly by

  14. Evidence for reticulospinal contributions to coordinated finger movements in humans

    PubMed Central

    Kharouta, Michael; Perreault, Eric Jon

    2013-01-01

    The reticulospinal tract was recently shown to have synaptic connections to the intrinsic muscles of the fingers in nonhuman primates, indicating it may contribute to hand function long thought to be controlled exclusively through corticospinal pathways. Our objective was to obtain evidence supporting the hypothesis that these same anatomical connections exist in humans. startReact, an involuntary release of a planned movement via the startle reflex, provides a noninvasive means to examine the reticulospinal tract in humans. We found that startReact was triggered during coordinated grasp but not individuated finger movements. This result suggests that the reticulospinal tract does have connections to the intrinsic muscles of the fingers in humans but its functional role is limited to coordinated movement of the whole hand. These results do not diminish the well-established role of corticospinal pathways in the control of hand movement. Indeed, they cement the significance of corticospinal pathways in individuated finger movement control. Still, these results point to an updated and expanded view of distal hand control where reticulospinal and corticospinal pathways work in parallel to generate a large repertoire of diverse, coordinated movement in the hand. Finally, the presence of reticulospinal pathways to the muscles of the hand makes this pathway an attractive therapeutic target for clinical populations where the corticospinal tract is absent or injured. PMID:23825395

  15. Out of One's Mind: A Study of Involuntary Semantic Memories

    ERIC Educational Resources Information Center

    Kvavilashvili, Lia; Mandler, George

    2004-01-01

    The study of memories that pop into one's mind without any conscious attempt to retrieve them began only recently. While there are some studies on involuntary autobiographical memories (e.g., Berntsen, 1996, 1998) research on involuntary semantic memories or mind-popping is virtually non-existent. The latter is defined as an involuntary conscious…

  16. Muscle atrophy is associated with cervical spinal motoneuron loss in BACHD mouse model for Huntington's disease.

    PubMed

    Valadão, Priscila Aparecida Costa; de Aragão, Bárbara Campos; Andrade, Jéssica Neves; Magalhães-Gomes, Matheus Proença S; Foureaux, Giselle; Joviano-Santos, Julliane Vasconcelos; Nogueira, José Carlos; Ribeiro, Fabíola Mara; Tapia, Juan Carlos; Guatimosim, Cristina

    2017-03-01

    Involuntary choreiform movements are clinical hallmark of Huntington's disease, an autosomal dominant neurodegenerative disorder caused by an increased number of CAG trinucleotide repeats in the huntingtin gene. Involuntary movements start with an impairment of facial muscles and then affect trunk and limbs muscles. Huntington's disease symptoms are caused by changes in cortex and striatum neurons induced by mutated huntingtin protein. However, little is known about the impact of this abnormal protein in spinal cord motoneurons that control movement. Therefore, in this study we evaluated abnormalities in the motor unit (spinal cervical motoneurons, motor axons, neuromuscular junctions and muscle) in a mouse model for Huntington's disease (BACHD). Using light, fluorescence, confocal, and electron microscopy, we showed significant changes such as muscle fibers atrophy, fragmentation of neuromuscular junctions, axonal alterations, and motoneurons death in BACHD mice. Noteworthy, the surviving motoneurons from BACHD spinal cords were smaller than WT. We suggest that this loss of larger putative motoneurons is accompanied by a decrease in the expression of fast glycolytic muscle fibers in this model for Huntington's disease. These observations show spinal cord motoneurons loss in BACHD that might help to understand neuromuscular changes in Huntington's disease.

  17. Factors Mediating the Adjustment to Involuntary Childlessness.

    ERIC Educational Resources Information Center

    Sabatelli, Ronald M.; And Others

    1988-01-01

    Explored stressors that accompany experience of involuntary childlessness and examined mediators of adjustment to infertility in married individuals. Data showed deleterious effect that coping with infertility can have on couple's sexual relationship. Findings suggest important relationship between self-esteem, marital commitment, and positive…

  18. Factors Mediating the Adjustment to Involuntary Childlessness.

    ERIC Educational Resources Information Center

    Sabatelli, Ronald M.; And Others

    1988-01-01

    Explored stressors that accompany experience of involuntary childlessness and examined mediators of adjustment to infertility in married individuals. Data showed deleterious effect that coping with infertility can have on couple's sexual relationship. Findings suggest important relationship between self-esteem, marital commitment, and positive…

  19. Involuntary Teacher Transfer: An Underexamined Practice

    ERIC Educational Resources Information Center

    Riordan, Kate E.

    2014-01-01

    Involuntary teacher transfer occurs whenever the reassignment of a teacher is initiated by a school or district rather than the teacher. These transitions are more likely to occur among special education teachers than among general education teachers. Although this type of transfer is not a new phenomenon, there has been surprisingly little…

  20. Involuntary Teacher Transfer: An Underexamined Practice

    ERIC Educational Resources Information Center

    Riordan, Kate E.

    2014-01-01

    Involuntary teacher transfer occurs whenever the reassignment of a teacher is initiated by a school or district rather than the teacher. These transitions are more likely to occur among special education teachers than among general education teachers. Although this type of transfer is not a new phenomenon, there has been surprisingly little…

  1. 32 CFR 584.9 - Involuntary allotments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... involuntary allotments from pay and allowances of soldiers on active duty as child, or child and spousal... the support and maintenance of a child. (3) Such notice must give the soldier's full name and SSN... National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY PERSONNEL FAMILY SUPPORT, CHILD...

  2. Treatment of an individual with piriformis syndrome focusing on hip muscle strengthening and movement reeducation: a case report.

    PubMed

    Tonley, Jason C; Yun, Steven M; Kochevar, Ronald J; Dye, Jeremy A; Farrokhi, Shawn; Powers, Christopher M

    2010-02-01

    Case report. To describe an alternative treatment approach for piriformis syndrome using a hip muscle strengthening program with movement reeducation. Interventions for piriformis syndrome typically consist of stretching and/or soft tissue massage to the piriformis muscle. The premise underlying this approach is that a shortening or "spasm" of the piriformis is responsible for the compression placed upon the sciatic nerve. The patient was a 30-year-old male with right buttock and posterior thigh pain for 2 years. Clinical findings upon examination included reproduction of symptoms with palpation and stretching of the piriformis. Movement analysis during a single-limb step-down revealed excessive hip adduction and internal rotation, which reproduced his symptoms. Strength assessment revealed weakness of the right hip abductor and external rotator muscles. The patient's treatment was limited to hip-strengthening exercises and movement reeducation to correct the excessive hip adduction and internal rotation during functional tasks. Following the intervention, the patient reported 0/10 pain with all activities. The initial Lower Extremity Functional Scale questionnaire score of 65/80 improved to 80/80. Lower extremity kinematics for peak hip adduction and internal rotation improved from 15.9 degrees and 12.8 degrees to 5.8 degrees and 5.9 degrees, respectively, during a step-down task. This case highlights an alternative view of the pathomechanics of piriformis syndrome (overstretching as opposed to overshortening) and illustrates the need for functional movement analysis as part of the examination of these patients. Therapy, level 4.

  3. The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis and hip.

    PubMed

    Andersson, E; Oddsson, L; Grundström, H; Thorstensson, A

    1995-02-01

    The activation patterns of the psoas and iliacus muscles were investigated in 7 healthy adult subjects (4 men and 3 women) during a variety of motor tasks in standing, sitting and lying. Myoelectric activity was recorded simultaneously from the 2 muscles using thin wire electrodes inserted under guidance of high-resolution ultrasound. In general, both muscles were coactivated, albeit to different relative levels, particularly when hip flexor torque was required. Selective activation of the iliacus could, however, be seen to stabilize the pelvis in contralateral hip extension during standing. Psoas was found to be selectively involved in sitting with a straight back and in contralateral loading situations requiring stabilization of the spine in the frontal plane. During training exercises from a supine position, such as sit-ups, the contribution of the psoas and iliacus muscles could be varied by changing the range of motion as well as the position and support for the legs. Thus, the 2 anatomically different muscles of the iliopsoas complex were shown to have individual and task-specific activation patterns depending on the particular demands for stability and movement at the lumbar spine, pelvis and hip.

  4. Evolution and homologies of primate and modern human hand and forearm muscles, with notes on thumb movements and tool use.

    PubMed

    Diogo, Rui; Richmond, Brian G; Wood, Bernard

    2012-07-01

    In this paper, we explore how the results of a primate-wide higher-level phylogenetic analysis of muscle characters can improve our understanding of the evolution and homologies of the forearm and hand muscles of modern humans. Contrary to what is often suggested in the literature, none of the forearm and hand muscle structures usually present in modern humans are autapomorphic. All are found in one or more extant non-human primate taxa. What is unique is the particular combination of muscles. However, more muscles go to the thumb in modern humans than in almost all other primates, reinforcing the hypothesis that focal thumb movements probably played an important role in human evolution. What makes the modern human thumb myology special within the primate clade is not so much its intrinsic musculature but two extrinsic muscles, extensor pollicis brevis and flexor pollicis longus, that are otherwise only found in hylobatids. It is likely that these two forearm muscles play different functional roles in hylobatids and modern humans. In the former, the thumb is separated from elongated digits by a deep cleft and there is no pulp-to-pulp opposition, whereas modern humans exhibit powerful thumb flexion and greater manipulative abilities, such as those involved in the manufacture and use of tools. The functional and evolutionary significance of a third peculiar structure, the intrinsic hand structure that is often called the 'interosseous volaris primus of Henle' (and which we suggest is referred to as the musculus adductor pollicis accessorius) is still obscure. The presence of distinct contrahentes digitorum and intermetacarpales in adult chimpanzees is likely the result of prolonged or delayed development of the hand musculature of these apes. In relation to these structures, extant chimpanzees are more neotenic than modern humans. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Exoskeleton control for lower-extremity assistance based on adaptive frequency oscillators: adaptation of muscle activation and movement frequency.

    PubMed

    Aguirre-Ollinger, Gabriel

    2015-01-01

    In this article, we analyze a novel strategy for assisting the lower extremities based on adaptive frequency oscillators. Our aim is to use the control algorithm presented here as a building block for the control of powered lower-limb exoskeletons. The algorithm assists cyclic movements of the human extremities by synchronizing actuator torques with the estimated net torque exerted by the muscles. Synchronization is produced by a nonlinear dynamical system combining an adaptive frequency oscillator with a form of adaptive Fourier analysis. The system extracts, in real time, the fundamental frequency component of the net muscle torque acting on a specific joint. Said component, nearly sinusoidal in shape, is the basis for the assistive torque waveform delivered by the exoskeleton. The action of the exoskeleton can be interpreted as a virtual reduction in the mechanical impedance of the leg. We studied the ability of human subjects to adapt their muscle activation to the assistive torque. Ten subjects swung their extended leg while coupled to a stationary hip joint exoskeleton. The experiment yielded a significant decrease, with respect to unassisted movement, of the activation levels of an agonist/antagonist pair of muscles controlling the hip joint's motion, which suggests the exoskeleton control has potential for assisting human gait. A moderate increase in swing frequency was observed as well. We theorize that the increase in frequency can be explained by the impedance model of the assisted leg. Per this model, subjects adjust their swing frequency in order to control the amount of reduction in net muscle torque. © IMechE 2015.

  6. Changes in cortical beta activity related to a biceps brachii movement task while experiencing exercise induced muscle damage.

    PubMed

    Plattner, Kristina; Lambert, Michael I; Tam, Nicholas; Lamberts, Robert P; Baumeister, Jochen

    2014-01-17

    Exercise-induced-muscle-damage (EIMD) is a well-described phenomenon which leads to decreased force output and altered neuromuscular function. How these symptoms of EIMD affect brain function, in particular cortical activity has not been described. Therefore the aim of this study was to investigate the relationship between the symptoms of EIMD and cortical beta (β) activity during a submaximal biceps brachii movement. Half of the subjects participated in an EIMD protocol. Control and EIMD groups were monitored for 132h thereafter. Muscle pain scores in the EIMD group peaked after 36h with the lowest muscle torque reported at 12h. Beta-1 and -2 activity was increased in the frontal and parietal area in the experimental group at 12h. This suggests an impact of EIMD induced neuromuscular changes on the cortical proprioceptive and motor perceptive networks. Beta-2 activity decreased in the control group over time suggesting a loss in focused attention and greater familiarization with the protocol as the study progressed. These data suggest that a change in β-1 and -2 activity is associated with integrating movement perception and proprioception post-EIMD. © 2013. Published by Elsevier Inc. All rights reserved.

  7. Effect of changing lumbar stiffness by single facet joint dysfunction on the responsiveness of lumbar muscle spindles to vertebral movement

    PubMed Central

    Reed, William R.; Pickar, Joel G.; Long, Cynthia R.

    2014-01-01

    Objective: Individuals experiencing low back pain often present clinically with intervertebral joint dysfunction. The purpose of this study was to determine whether relative changes in stiffness at a single spinal joint alters neural responsiveness of lumbar muscle spindles to either vertebral movement or position. Methods: Muscle spindle discharge was recorded in response to 1mm L6 ramp and hold movements (0.5mm/s) in the same animal for lumbar laminectomy-only (n=23), laminectomy & L5/6 facet screw (n=19), laminectomy & L5/6 facetectomy (n=5) conditions. Mean instantaneous frequency (MIF) was calculated for the ramp-up, hold, ramp-down and post-ramp phases during each joint condition. Results: Mean MIFs were not significantly different between the laminectomy-only and the other two types of joint dysfunction for the ramp-up, hold, ramp-down, or post-ramp phases. Conclusion: Stiffness changes caused by single facet joint dysfunction failed to alter spindle responses during slow 1mm ramp and hold movements of the L6 vertebra. PMID:24932020

  8. Muscle coordination is key to the power output and mechanical efficiency of limb movements.

    PubMed

    Wakeling, J M; Blake, O M; Chan, H K

    2010-02-01

    The purpose of this study was to determine which features of muscle mechanics and muscle coordination affect the power output from a limb during locomotion. Eight subjects were tested while cycling at maximum exertion for 25 min on a stationary dynamometer. Cadence and load were varied to span a range of power outputs and myoelectric activity was measured from 10 muscles in the leg. Cycle-by-cycle variations in muscle coordination, cadence and power output were observed and the EMG intensity across all muscles was used as an estimate of the metabolic cost for each cycle. Data for the cycles at greatest power output were separated into three groups: maximum power, 80% power but lower EMG intensity and 80% power and higher EMG intensity. Torque-angular velocity relations were determined for the ankle and knee joints. During cycling at maximum power output the ankle joint was not extending at the velocity necessary for maximum power output; thus, maximum limb power occurs when some of the individual muscles cannot be generating maximum power output. Increases in EMG intensity occurred with no increase in power output from the limb: these corresponded to decreases in the efficiency and changes in coordination. Increases in power were achieved that were not matched by equivalent increases in EMG intensity, but did occur with changes in coordination. It is proposed that the power output from the limb is limited by the coordination pattern of the muscles rather than the maximum power output from any one muscle itself.

  9. [Case of painful muscle spasm induced by thoracic vertebral fracture: successful treatment with lumbar sympathetic ganglia block].

    PubMed

    Shimizu, Fumitaka; Kawai, Motoharu; Koga, Michiaki; Ogasawara, Jun-ichi; Negoro, Kiyoshi; Kanda, Takashi

    2008-10-01

    We report a 70-year-old man, who developed painful involuntary muscle contraction of the left leg after the lumbar discectomy, which exacerbated after a vertebral fracture of Th12. This involuntary movement was accompanied with the abnormal position of left leg simulating triple flexion response, and was induced by active or passive movement of his left knee and foot joints. Several drugs including benzodiazepines and dantrolene were ineffective, although treatment with baclofen or carbamazepine was effective. These findings suggest that hyperexcitability of the anterior horn cells following the disturbance of spinal inhibitory interneurons was involved. Electophysiological studies suggested the disturbance of left lumber nerve roots. The spinal root blocks from L3 to S1 were performed, after which the painful involuntary muscle spasm was resolved. The lumbar sympathetic ganglia block was also effective; suggesting that abnormal afferent neuronal input to spinal cord was caused by the nerve root trauma which triggered the formation of secondary abnormal network in the spine. Lumbar sympathetic ganglia block should be recommended to a therapeutic option for the refractory painful muscle spasm of the leg.

  10. A framework for using signal, noise, and variation to determine whether the brain controls movement synergies or single muscles.

    PubMed

    Joshua, Mati; Lisberger, Stephen G

    2014-02-01

    We have used an analysis of signal and variation in motor behavior to elucidate the organization of the cerebellar and brain stem circuits that control smooth pursuit eye movements. We recorded from the abducens nucleus and identified floccular target neurons (FTNs) and other, non-FTN vestibular neurons. First, we assessed neuron-behavior correlations, defined as the trial-by-trial correlation between the variation in neural firing and eye movement, in brain stem neurons. In agreement with prior data from the cerebellum, neuron-behavior correlations during pursuit initiation were large in all neurons. Second, we asked whether movement variation arises upstream from, in parallel to, or downstream from a given site of recording. We developed a model that highlighted two measures: the ratio of the SDs of neural firing rate and eye movement ("SDratio") and the neuron-behavior correlation. The relationship between these measures defines possible sources of variation. During pursuit initiation, SDratio was approximately equal to neuron-behavior correlation, meaning that the source of signal and variation is upstream from the brain stem. During steady-state pursuit, neuron-behavior correlation became somewhat smaller than SDratio for FTNs, meaning that some variation may arise downstream in the brain stem. The data contradicted the model's predictions for sources of variation in pathways that run parallel to the site of recording. Because signal and noise are tightly linked in motor control, we take the source of variation as a proxy for the source of signal, leading us to conclude that the brain controls movement synergies rather than single muscles for eye movements.

  11. A framework for using signal, noise, and variation to determine whether the brain controls movement synergies or single muscles

    PubMed Central

    Lisberger, Stephen G.

    2013-01-01

    We have used an analysis of signal and variation in motor behavior to elucidate the organization of the cerebellar and brain stem circuits that control smooth pursuit eye movements. We recorded from the abducens nucleus and identified floccular target neurons (FTNs) and other, non-FTN vestibular neurons. First, we assessed neuron-behavior correlations, defined as the trial-by-trial correlation between the variation in neural firing and eye movement, in brain stem neurons. In agreement with prior data from the cerebellum, neuron-behavior correlations during pursuit initiation were large in all neurons. Second, we asked whether movement variation arises upstream from, in parallel to, or downstream from a given site of recording. We developed a model that highlighted two measures: the ratio of the SDs of neural firing rate and eye movement (“SDratio”) and the neuron-behavior correlation. The relationship between these measures defines possible sources of variation. During pursuit initiation, SDratio was approximately equal to neuron-behavior correlation, meaning that the source of signal and variation is upstream from the brain stem. During steady-state pursuit, neuron-behavior correlation became somewhat smaller than SDratio for FTNs, meaning that some variation may arise downstream in the brain stem. The data contradicted the model's predictions for sources of variation in pathways that run parallel to the site of recording. Because signal and noise are tightly linked in motor control, we take the source of variation as a proxy for the source of signal, leading us to conclude that the brain controls movement synergies rather than single muscles for eye movements. PMID:24259547

  12. Activation timing patterns of the abdominal and leg muscles during the sit-to-stand movement in individuals with chronic hemiparetic stroke.

    PubMed

    Lee, Tae-Heon; Choi, Jong-Duk; Lee, Nam-Gi

    2015-11-01

    [Purpose] The purpose of this study was to determine the activation timing patterns of abdominal and leg muscles during the sit-to-stand movement in individuals with chronic hemiparetic stroke. [Subjects] Twenty adults with chronic hemiparetic stroke participated in this study. [Methods] Subjects performed five sit-to-stand movements at a self-selected velocity without using their hands. Surface electromyography was used to measure the reaction time of the bilateral transverse abdominis/internal oblique, rectus femoris, and tibialis anterior muscles during the sit-to-stand movement. [Results] There were significant differences in the reaction time between the affected and unaffected sides of the abdominal and leg muscles. Muscles on the unaffected side had faster reaction time than those on the affected side. Activation of the transverse abdominis/internal oblique muscles was delayed relative to activation of the tibialis anterior muscle during the sit-to-stand movement. [Conclusion] Our findings provide information that may aid clinicians in the examination and management of paretic muscles for transfers in individuals with chronic hemiparetic stroke.

  13. The relationship of force output characteristics during a sit-to-stand movement with lower limb muscle mass and knee joint extension in the elderly.

    PubMed

    Yamada, Takayoshi; Demura, Shinichi

    2010-01-01

    This study examined the reliability of ground reaction force (GRF) parameters during sit-to-stand (STS) movements and the relationships between the GRF parameters and lower limb muscle mass and knee extension muscle strength. Fifty elderly females performed an STS movement twice from a chair adjusted to their knee height and the GRF, lower limb muscle mass and isometric knee extension muscle strength were measured. Reliabilities of GRF parameters were high (intra-class correlation coefficient=ICC=0.70-0.95). Parameters on force output during trunk flexion phase (ground reaction force at hip-lift off, sum of force output between beginning of STS movement and hip-lift off) differed significantly between trials, but their effect sizes were small (0.15-0.23). GRF parameters during hip-lift off and knee-hip joint extension phases significantly correlated with knee extension strength (|r|=0.29-0.64) but not lower limb muscle mass. In conclusion, the reliability of GRF during STS movement is good in hip-lift off and knee-hip joint extension phases and these phases relate significantly with lower limb muscle function. These two phases are useful for evaluation of leg muscle function of the elderly.

  14. Evaluation of the effects of the Arm Light Exoskeleton on movement execution and muscle activities: a pilot study on healthy subjects.

    PubMed

    Pirondini, Elvira; Coscia, Martina; Marcheschi, Simone; Roas, Gianluca; Salsedo, Fabio; Frisoli, Antonio; Bergamasco, Massimo; Micera, Silvestro

    2016-01-23

    Exoskeletons for lower and upper extremities have been introduced in neurorehabilitation because they can guide the patient's limb following its anatomy, covering many degrees of freedom and most of its natural workspace, and allowing the control of the articular joints. The aims of this study were to evaluate the possible use of a novel exoskeleton, the Arm Light Exoskeleton (ALEx), for robot-aided neurorehabilitation and to investigate the effects of some rehabilitative strategies adopted in robot-assisted training. We studied movement execution and muscle activities of 16 upper limb muscles in six healthy subjects, focusing on end-effector and joint kinematics, muscle synergies, and spinal maps. The subjects performed three dimensional point-to-point reaching movements, without and with the exoskeleton in different assistive modalities and control strategies. The results showed that ALEx supported the upper limb in all modalities and control strategies: it reduced the muscular activity of the shoulder's abductors and it increased the activity of the elbow flexors. The different assistive modalities favored kinematics and muscle coordination similar to natural movements, but the muscle activity during the movements assisted by the exoskeleton was reduced with respect to the movements actively performed by the subjects. Moreover, natural trajectories recorded from the movements actively performed by the subjects seemed to promote an activity of muscles and spinal circuitries more similar to the natural one. The preliminary analysis on healthy subjects supported the use of ALEx for post-stroke upper limb robotic assisted rehabilitation, and it provided clues on the effects of different rehabilitative strategies on movement and muscle coordination.

  15. Relationship between muscle-tendon length, range of motion, and resistance to passive movement in children with normal and increased tone

    PubMed Central

    Matsukiyo, Ayumi; Goh, Ah-Cheng; Asagai, Yoshimi

    2017-01-01

    [Purpose] The aim of this study was to quantify the resistance to passive movement by measuring changes in muscle-tendon length and joint range of motion (ROM), before and after applying a standardized 5-kilogram tension force, and to correlate and compare these changes to muscle tone. [Subjects and Methods] Children with cerebral palsy (n=29) and typically developed children (n=12) participated in this observational study. The modified Ashworth scale (MAS) was used to assess tone in the right plantarflexor muscle. An ultrasound-imaging device was used to measure Δmuscle-tendon length in the right medial gastrocnemius muscle, and a goniometer was used to measure right ankle ΔROM. [Results] Compared with the MAS, the results showed that ΔROM had the highest construct validity (convergent and discriminant) followed by Δmuscle-tendon unit length. Therefore, these parameters may be better alternatives to the MAS for the quantitative assessment of resistance to passive movement in patients with increased tone. [Conclusion] This study demonstrated that measuring the change in the passive properties of the muscle-tendon unit, as well as the corresponding change in ROM, might provide better options for assessing resistance to passive movement or muscle tone. PMID:28265172

  16. Masseter length determines muscle spindle reflex excitability during jaw-closing movements.

    PubMed

    Naser-Ud-Din, Shazia; Sowman, Paul F; Sampson, Wayne J; Dreyer, Craig W; Türker, Kemal Sitki

    2011-04-01

    The masticatory muscles are considered to be important determinants of facial form, but little is known of the muscle spindle reflex characteristics and their relationship, if any, to face height. The aim of this study was to determine whether spindle reflexes, evoked by mechanical stimulation of an incisor and recorded on the masseter muscle, correlated with different facial patterns. Twenty-eight adult volunteers (16 women; ages, 19-38 years) underwent 2-N tap stimuli to their maxillary left central incisor during simulated mastication. Reflexes were recorded during local anesthesia of the stimulated tooth to eliminate the contribution from periodontal mechanoreceptors. Surface electromyograms of the reflex responses of the jaw muscles to these taps were recorded via bipolar electrodes on the masseter muscle and interpreted by using spike-triggered averaging of the surface electromyograms. Lateral cephalometric analysis was carried out with software (version 10.5, Dolphin, Los Angeles, Calif; and Mona Lisa, Canberra, Australia). Two-newton tooth taps produced principally excitatory reflex responses beginning at 17 ms poststimulus. Correlation analysis showed a significant relationship between these muscle spindle reflexes and facial heights: specifically, shorter face heights were associated with stronger spindle reflexes. This correlation was strongest between the derived measure of masseter length and the spindle reflex strength during jaw closure (r = -0.49, P = 0.008). These results suggest that a similar muscle spindle stimulus will generate a stronger reflex activation in the jaw muscles of patients with shorter faces compared with those with longer faces. This finding might help to explain the higher incidence of clenching or bruxism in those with short faces and also might, in the future, influence the design of orthodontic appliances and dental prostheses. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights

  17. Single motor unit firing behavior in the right trapezius muscle during rapid movement of right or left index finger.

    PubMed

    Søgaard, Karen; Olsen, Henrik B; Blangsted, Anne K; Sjøgaard, Gisela

    2014-01-01

    Computer work is associated with low level sustained activity in the trapezius muscle that may cause development of trapezius myalgia. Such a low level activity may be attention related or alternatively, be part of a general multi joint motor program providing stabilization of the shoulder joint as a biomechanical prerequisite for precise finger manipulation. This study examines single motor unit (MU) firing pattern in the right trapezius muscle during fast movements of ipsilateral or contralateral index finger. A modulation of the MU firing rate would support the existence of a general multi joint motor program, while a generally increased and continuous firing rate would support the attention related muscle activation. Twelve healthy female subjects were seated at a computer work place with elbows and forearms supported. Ten double clicks (DC) were performed with right and left index finger on a computer mouse instrumented with a trigger. Surface electromyographic signals (EMG) was recorded from right and left trapezius muscle. Intramuscular EMG was recorded with a quadripolar wire electrode inserted into the right trapezius. Surface EMG was analyzed as RMS and presented as %MVE. The intramuscular EMG signals were decomposed into individual MU action potential trains using a computer algorithm based on signal shape recognition and manual editing. Instantaneous firing rate (IFR) was calculated as the inverse of each inter-spike interval (ISI). All ISI shorter than 20 ms were defined as doublets. For all MU IFR was spike triggered averaged across the 10 DC to show the modulation during DC as well as for calculation of the cross correlation coefficient (CCC). All subjects showed surface EMG activity in both right and left trapezius ranging from 1.8 %MVE to 2.5 %MVE. Regarding intramuscular EMG during right hand DC a total of 32 MUs were identified. Four subjects showed no MU activity. Four showed MU activity with low mean firing rate (MFR) with weak or no variations

  18. The effect of muscle fatigue and low back pain on lumbar movement variability and complexity.

    PubMed

    Bauer, C M; Rast, F M; Ernst, M J; Meichtry, A; Kool, J; Rissanen, S M; Suni, J H; Kankaanpää, M

    2017-04-01

    Changes in movement variability and complexity may reflect an adaptation strategy to fatigue. One unresolved question is whether this adaptation is hampered by the presence of low back pain (LBP). This study investigated if changes in movement variability and complexity after fatigue are influenced by the presence of LBP. It is hypothesised that pain free people and people suffering from LBP differ in their response to fatigue. The effect of an isometric endurance test on lumbar movement was tested in 27 pain free participants and 59 participants suffering from LBP. Movement variability and complexity were quantified with %determinism and sample entropy of lumbar angular displacement and velocity. Generalized linear models were fitted for each outcome. Bayesian estimation of the group-fatigue effect with 95% highest posterior density intervals (95%HPDI) was performed. After fatiguing %determinism decreased and sample entropy increased in the pain free group, compared to the LBP group. The corresponding group-fatigue effects were 3.7 (95%HPDI: 2.3-7.1) and -1.4 (95%HPDI: -2.7 to -0.1). These effects manifested in angular velocity, but not in angular displacement. The effects indicate that pain free participants showed more complex and less predictable lumbar movement with a lower degree of structure in its variability following fatigue while participants suffering from LBP did not. This may be physiological responses to avoid overload of fatigued tissue, increase endurance, or a consequence of reduced movement control caused by fatigue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Tropomyosin movement is described by a quantitative high-resolution model of X-ray diffraction of contracting muscle.

    PubMed

    Koubassova, Natalia A; Bershitsky, Sergey Y; Ferenczi, Michael A; Narayanan, Theyencheri; Tsaturyan, Andrey K

    2017-05-01

    Contraction of skeletal and cardiac muscle is controlled by Ca(2+) ions via regulatory proteins, troponin (Tn) and tropomyosin (Tpm) associated with the thin actin filaments in sarcomeres. In the absence of Ca(2+), Tn-C binds actin and shifts the Tpm strand to a position where it blocks myosin binding to actin, keeping muscle relaxed. According to the three-state model (McKillop and Geeves Biophys J 65:693-701, 1993), upon Ca(2+) binding to Tn, Tpm rotates about the filament axis to a 'closed state' where some myosin heads can bind actin. Upon strong binding of myosin heads to actin, Tpm rotates further to an 'open' position where neighboring actin monomers also become available for myosin binding. Azimuthal Tpm movement in contracting muscle is detected by low-angle X-ray diffraction. Here we used high-resolution models of actin-Tpm filaments based on recent cryo-EM data for calculating changes in the intensities of X-ray diffraction reflections of muscle upon transitions between different states of the regulatory system. Calculated intensities of actin layer lines provide a much-improved fit to the experimental data obtained from rabbit muscle fibers in relaxed and rigor states than previous lower-resolution models. We show that the intensity of the second actin layer line at reciprocal radii from 0.15 to 0.3 nm(-1) quantitatively reports the transition between different states of the regulatory system independently of the number of myosin heads bound to actin.

  20. Sleep deprivation and phasic activity of REM sleep: independence of middle-ear muscle activity from rapid eye movements.

    PubMed

    De Gennaro, L; Ferrara, M

    2000-02-01

    In the recovery nights after total and partial sleep deprivation there is a reduction of rapid eye movements during REM sleep as compared to baseline nights; recent evidence provided by a selective SWS deprivation study also shows that the highest percentage of variance of this reduction is explained by SWS rebound. The present study assesses whether the reduction of rapid eye movements (REMs) during the recovery night after total sleep deprivation is paralleled by a decrease of middle-ear muscle activity (MEMA), another phasic muscle activity of REM sleep. Standard polysomnography, MEMA and REMs of nine subjects were recorded for three nights (one adaptation, one baseline, one recovery); baseline and recovery night were separated by a period of 40 hours of continuous wake. Results show that, in the recovery night, sleep deprivation was effective in determining an increase of SWS amount and of the sleep efficiency index, and a decrease of stage 1, stage 2, intra-sleep wake, and NREM latencies, without affecting REM duration and latency. However, MEMA frequency during REM sleep did not diminish during these nights as compared to baseline ones, while there was a clear effect of REM frequency reduction. Results indicate an independence of phasic events of REM sleep, suggesting that the inverse relation between recovery sleep after sleep deprivation and REM frequency is not paralleled by a concomitant variation in MEMA frequency.

  1. Can fast-twitch muscle fibres be selectively recruited during lengthening contractions? Review and applications to sport movements.

    PubMed

    Chalmers, Gordon R

    2008-01-01

    Literature examining the recruitment order of motor units during lengthening (eccentric) contractions was reviewed to determine if fast-twitch motor units can be active while lower threshold slow-twitch motor units are not active. Studies utilizing surface electromyogram (EMG) amplitude, single motor unit activity, spike amplitude-frequency analyses, EMG power spectrum, mechanomyographic, and phosphocreatine-to-creatine ratio (PCr/Cr) techniques were reviewed. Only single motor unit and PCr/Cr data were found to be suitable to address the goals of this review. Nine of ten single motor unit studies, examining joint movement velocities up to 225 degrees/s and forces up to 53% of a maximum voluntary contraction, found that the size principle of motor unit recruitment applied during lengthening contractions. Deviation from the size principle was demonstrated by one study examining movements within a small range of low velocities and modest forces, although other studies examining similar low forces and lengthening velocities reported size-ordered recruitment. The PCr/Cr data demonstrated the activation of all fibre types in lengthening maximal contractions. Most evidence indicates that for lengthening contractions of a wide range of efforts and speeds, fast-twitch muscle fibres cannot be selectively recruited without activity of the slow-twitch fibres of the same muscle.

  2. Calcium release and intramembranous charge movement in frog skeletal muscle fibres with reduced (<250 μM) calcium content

    PubMed Central

    Pape, Paul C; Carrier, Nicole

    2002-01-01

    It is generally accepted that activation of voltage sensors in the T-tubular membranes is a critical step of excitation-contraction coupling in skeletal muscle. The purpose of this study was to evaluate further whether the Qγ component (delayed [hump] component) of the intramembranous charge movement current (Icm) results from movement of these voltage sensors. Ca2+ release and Icm were measured in voltage-clamped frog cut fibres mounted in a double Vaseline-gap chamber. In order to reduce effects of Ca2+ feedback mechanisms, the calcium content of the sarcoplasmic reticulum (SR) during rest was reduced to < 250 μm (referred to volume of myoplasm) and maintained approximately constant. The early (Qβ) and Qγ components of charge movement were estimated by fitting the sum of two Boltzmann functions to the total steady-state intramembranous charge vs. voltage data. The average voltage steepness factor (k) and half-maximal voltage (V-) for Qγ were 4.3 and −57.4 mV (n = 6), respectively. The SR membrane permeability for Ca2+ release was assessed when a constant amount of calcium remained in the SR (usually about 60 μm). A single Boltzmann function fitted to these data gave values on average for k and V- of 4.7 and −45.3 mV, respectively. The similarity of the values of k for Qγ and Ca2+ release supports the idea that Qγ reflects movement of voltage sensors for Ca2+ release. The greater value of V- for Ca2+ release compared to Qγ is consistent with multi-state models of the voltage sensor involving movement of Qγ charge during non-activating transitions. PMID:11850517

  3. The effects of voluntary, involuntary, and forced exercises on brain-derived neurotrophic factor and motor function recovery: a rat brain ischemia model.

    PubMed

    Ke, Zheng; Yip, Shea Ping; Li, Le; Zheng, Xiao-Xiang; Tong, Kai-Yu

    2011-02-08

    Stroke rehabilitation with different exercise paradigms has been investigated, but which one is more effective in facilitating motor recovery and up-regulating brain neurotrophic factor (BDNF) after brain ischemia would be interesting to clinicians and patients. Voluntary exercise, forced exercise, and involuntary muscle movement caused by functional electrical stimulation (FES) have been individually demonstrated effective as stroke rehabilitation intervention. The aim of this study was to investigate the effects of these three common interventions on brain BDNF changes and motor recovery levels using a rat ischemic stroke model. One hundred and seventeen Sprague-Dawley rats were randomly distributed into four groups: Control (Con), Voluntary exercise of wheel running (V-Ex), Forced exercise of treadmill running (F-Ex), and Involuntary exercise of FES (I-Ex) with implanted electrodes placed in two hind limb muscles on the affected side to mimic gait-like walking pattern during stimulation. Ischemic stroke was induced in all rats with the middle cerebral artery occlusion/reperfusion model and fifty-seven rats had motor deficits after stroke. Twenty-four hours after reperfusion, rats were arranged to their intervention programs. De Ryck's behavioral test was conducted daily during the 7-day intervention as an evaluation tool of motor recovery. Serum corticosterone concentration and BDNF levels in the hippocampus, striatum, and cortex were measured after the rats were sacrificed. V-Ex had significantly better motor recovery in the behavioral test. V-Ex also had significantly higher hippocampal BDNF concentration than F-Ex and Con. F-Ex had significantly higher serum corticosterone level than other groups. Voluntary exercise is the most effective intervention in upregulating the hippocampal BDNF level, and facilitating motor recovery. Rats that exercised voluntarily also showed less corticosterone stress response than other groups. The results also suggested that the

  4. The coordination of shoulder girdle muscles during repetitive arm movements at either slow or fast pace among women with or without neck-shoulder pain.

    PubMed

    Januario, Leticia Bergamin; Oliveira, Ana Beatriz; Cid, Marina Machado; Madeleine, Pascal; Samani, Afshin

    2017-09-11

    The aim of this study was to evaluate the coordination of the shoulder girdle muscles among subjects with or without neck-shoulder pain performing repetitive arm movement at either a slow or fast pace. Thirty female adults were allocated to one of two groups-healthy controls or cases with neck-shoulder pain. Surface electromyography (sEMG) signals from the clavicular, acromial, middle and lower trapezius portions and the serratus anterior muscles were recorded during a task performed for 20min at a slow pace and 20min at a fast pace. The root mean square (RMS), relative rest time (RRT) and normalised mutual information (NMI, an index of functional connectivity between two muscles in a pair) were computed. No significant differences on RMS, RRT and NMI were found between groups. For both groups, the fast movement pace resulted in increased levels of RMS, lower degrees of RRT and higher NMI compared to the slow pace. No interaction between group and movement pace was found. This study highlights the change in sEMG activity of muscles to meet the demands of performing a task at fast movement pace. The fast pace imposed a higher muscle demand evidenced by increased sEMG amplitude, low degree of muscle rest and increased functional connectivity for subjects in both the case and control groups. No indication of impaired sEMG activity was found in individuals with neck-shoulder pain. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Electromyographic comparison of forearm muscle movements for fine skin suturing between an enlarged pen needle holder and a webster needle holder.

    PubMed

    Ohata, Erika; Matsuo, Kiyoshi; Ban, Ryokuya; Shiba, Masato; Yasunaga, Yoshichika

    2013-01-01

    For surgical suturing, a Webster needle holder uses wrist supinating with supinator and extrinsic muscles, whereas a pen needle holder uses finger twisting with intrinsic and extrinsic muscles. Because the latter is better suited to microsurgery, which requires fine suturing with less forearm muscle movement, we have recently adopted an enlarged pen needle holder scaled from a micro needle holder for fine skin suturing. In this study, we assessed whether the enlarged pen needle holder reduced forearm muscle movement during fine skin suturing as compared with the Webster needle holder. A fine skin-suturing task was performed using pen holding with the enlarged micro needle holder or scissor holding with the Webster needle holder by 9 experienced and 6 inexperienced microsurgeons. The task lasted for 60 seconds and was randomly performed 3 times for each method. Forearm flexor and extensor muscular activities were evaluated by surface electromyography. The enlarged pen needle holder method required significantly less forearm muscle movement for experienced microsurgeons despite it being their first time using the instrument. There was no significant difference between 2 methods for inexperienced microsurgeons. Experienced microsurgeons conserved forearm muscle movement by finger twisting in fine skin suturing with the enlarged pen needle holder. Inexperienced microsurgeons may benefit from the enlarged pen needle holder, even for fine skin suturing, to develop their internal acquisition model of the dynamics of finger twisting.

  6. Anchoring the "floating arm": Use of proprioceptive and mirror visual feedback from one arm to control involuntary displacement of the other arm.

    PubMed

    Brun, C; Guerraz, M

    2015-12-03

    Arm movement control takes advantage of multiple inputs, including those originating from the contralateral arm. In the mirror paradigm, it has been suggested that control of the unseen arm, hidden by the mirror, is facilitated by the reflection of the other, moving arm. Although proprioceptive feedback originating from the moving arm, (the image of which is reflected in the mirror), is always coupled with visual feedback in the mirror paradigm, the former has received little attention. We recently showed that the involuntary arm movement following a sustained, isometric contraction, known as the "floating arm" or "Kohnstamm phenomenon", was adjusted to the passive-motorized displacement of the other arm. However, provision of mirror feedback, that is, the reflection in the mirror of the passively moved arm, did not add to this coupling effect. Therefore, the interlimb coupling in the mirror paradigm may to a large extent have a proprioceptive origin rather than a visual origin. The objective of the present study was to decouple mirror feedback and proprioceptive feedback from the reflected, moving arm and evaluate their respective contributions to interlimb coupling in the mirror paradigm. First (in Experiment 1, under eyes-closed conditions), we found that masking the proprioceptive afferents of the passively moved arm (by co-vibrating the antagonistic biceps and triceps muscles) suppressed the interlimb coupling between involuntary displacement of one arm and passive displacement of the other. Next (in Experiment 2), we masked proprioceptive afferents of the passively moved arm and specifically evaluated mirror feedback. We found that interlimb coupling through mirror feedback (though significant) was weaker than interlimb coupling through proprioceptive feedback. Overall, the present results show that in the mirror paradigm, proprioceptive feedback is stronger and more consistent than visual-mirror feedback in terms of the impact on interlimb coupling.

  7. Proactive Selective Inhibition Targeted at the Neck Muscles: This Proximal Constraint Facilitates Learning and Regulates Global Control.

    PubMed

    Loram, Ian D; Bate, Brian; Harding, Pete; Cunningham, Ryan; Loram, Alison

    2017-04-01

    While individual muscle function is known, the sensory and motor value of muscles within the whole-body sensorimotor network is complicated. Specifically, the relationship between neck muscle action and distal muscle synergies is unknown. This work demonstrates a causal relationship between regulation of the neck muscles and global motor control. Studying violinists performing unskilled and skilled manual tasks, we provided ultrasound feedback of the neck muscles with instruction to minimize neck muscle change during task performance and observed the indirect effect on whole-body movement. Analysis of ultrasound, kinematic, electromyographic and electrodermal recordings showed that proactive inhibition targeted at neck muscles had an indirect global effect reducing the cost of movement, reducing complex involuntary, task-irrelevant movement patterns and improving balance. This effect was distinct from the effect of gaze alignment which increased physiological cost and reduced laboratory-referenced movement. Neck muscle inhibition imposes a proximal constraint on the global motor plan, forcing a change in highly automated sensorimotor control. The proximal location ensures global influence. The criterion, inhibition of unnecessary action, ensures reduced cost while facilitating task-relevant variation. This mechanism regulates global motor function and facilitates reinforcement learning to change engrained, maladapted sensorimotor control associated with chronic pain, injury and performance limitation.

  8. The influence of muscle tremor on shooting performance.

    PubMed

    Lakie, Martin

    2010-03-01

    Shooting ability is compromised by involuntary movement. Some of this movement is physiological tremor. Tremor size has a demonstrable inverse correlation with shooting performance. Consequently, factors which affect tremor size should affect shooting ability. Adrenaline and local muscle warming markedly increase tremor size, whereas local muscle cooling reduces it. The physiological mechanisms behind these changes are not well understood, but they have the potential to affect shooting performance in subjects who exercise heavily and/or are exposed to extreme environments. The Olympic biathlon is an event in which vigorous physical exercise alternates with rifle shooting and it often takes place in a cold environment. The possible impact of exercise, temperature and other factors on the Olympic biathlete is considered here.

  9. Excitability changes in the left primary motor cortex innervating the hand muscles induced during speech about hand or leg movements.

    PubMed

    Onmyoji, Yusuke; Kubota, Shinji; Hirano, Masato; Tanaka, Megumi; Morishita, Takuya; Uehara, Kazumasa; Funase, Kozo

    2015-05-06

    In the present study, we used transcranial magnetic stimulation (TMS) to investigate the changes in the excitability of the left primary motor cortex (M1) innervating the hand muscles and in short-interval intracortical inhibition (SICI) during speech describing hand or leg movements. In experiment 1, we investigated the effects of the contents of speech on the amplitude of the motor evoked potentials (MEPs) induced during reading aloud and silent reading. In experiment 2, we repeated experiment 1 with an additional condition, the non-vocal oral movement (No-Voc OM) condition, and investigated the change in SICI induced in each condition using the paired TMS paradigm. The MEP observed in the reading aloud and No-Voc OM conditions exhibited significantly greater amplitudes than those seen in the silent reading conditions, irrespective of the content of the sentences spoken by the subjects or the timing of the TMS. There were no significant differences in SICI between the experimental conditions. Our findings suggest that the increased excitability of the left M1 hand area detected during speech was mainly caused by speech-related oral movements and the activation of language processing-related brain functions. The increased left M1 excitability was probably also mediated by neural mechanisms other than reduced SICI; i.e., disinhibition. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Suicidality and Hostility following Involuntary Hospital Treatment

    PubMed Central

    Giacco, Domenico; Priebe, Stefan

    2016-01-01

    Background Psychiatric patients showing risk to themselves or others can be involuntarily hospitalised. No data is available on whether following hospitalisation there is a reduction in psychopathological indicators of risk such as suicidality and hostility. This study aimed to assess changes in suicidality and hostility levels following involuntary admission and their patient-level predictors. Methods A pooled analysis of studies on involuntary treatment, including 11 countries and 2790 patients was carried out. Suicidality and hostility were measured by the Brief Psychiatric Rating Scale. Results 2790 patients were included; 2129 followed-up after one month and 1864 after three months. 387 (13.9%) patients showed at least moderate suicidality when involuntarily admitted, 107 (5.0%) after one month and 97 (5.2%) after three months. Moderate or higher hostility was found in 1287 (46.1%) patients after admission, 307 (14.5%) after one month, and 172 (9.2%) after three months. Twenty-three (1.2%) patients showed suicidality, and 53 (2.8%) patients hostility at all time-points. Predictors of suicidality three months after admission were: suicidality at baseline, not having a diagnosis of psychotic disorder and being unemployed. Predictors of hostility were: hostility at baseline, not having a psychotic disorder, living alone, and having been hospitalized previously. Conclusions After involuntary hospital admission, the number of patients with significant levels of suicidality and hostility decreases substantially over time, and very few patients show consistently moderate or higher levels of these symptoms. In patients with psychotic disorders these symptoms are more likely to improve. Social factors such as unemployment and isolation could hamper suicidality and hostility reduction and may be targeted in interventions to reduce risk in involuntarily admitted patients. PMID:27171229

  11. Involuntary mass spirit possession among the Miskitu.

    PubMed

    Wedel, Johan

    2012-01-01

    This paper seeks to understand the outbreaks and the development of grisi siknis, a form of mass spirit possession among the Miskitu of north-eastern Nicaragua. Earlier documented outbreaks typically involved a few adolescents, however, in recent years, violent large-scale epidemics have taken place, involving many people of all ages. This has coincided with recent developments in Miskitu society marked by conflicts, contradictions and tense social relations. The anthropological field technique of participant-observation was used. The research took place during 11 months from 2005 to 2008 in the port town of Puerto Cabezas. A total of 38 informants were interviewed. Group discussions, narratives and informal and semi-structured interviews were carried out, as well as participation in healing rituals. The paper shows that socio-economic, cultural, personal as well as environmental factors all contribute to outbreaks of grisi siknis. The affliction has previously been considered a 'culture-bound syndrome' only occurring among the Miskitu. However, when viewed in a more contemporary context and cross-cultural perspective, grisi siknis shows similarities with other forms of involuntary mass spirit possession, particularly in the ways it is manifested, experienced and appears to be spreading. The paper argues that the phenomenon should no longer be considered a 'culture-bound condition' but in fact a Miskitu version of involuntary mass spirit possession. Further research that seeks to understand other forms of involuntary mass spirit possession should emphasize the social, personal and environmental context as well as cross-cultural comparisons in order to encompass fully the role of culture in relation to illness and suffering.

  12. Involuntary outpatient treatment (IOT) in Spain.

    PubMed

    Hernández-Viadel, M; Cañete-Nicolás, C; Bellido-Rodriguez, C; Asensio-Pascual, P; Lera-Calatayud, G; Calabuig-Crespo, R; Leal-Cercós, C

    2015-01-01

    In recent decades there have been significant legislative changes in Spain. Society develops faster than laws, however, and new challenges have emerged. In 2004, the Spanish Association of Relatives of the Mentally Ill (FEAFES) proposed amending the existing legislation to allow for the implementation of involuntary outpatient treatment (IOT) for patients with severe mental illness. Currently, and after having made several attempts at change, there is no specific legislation governing the application of this measure. Although IOT may be implemented in local programmes, we consider legal regulation to be needed in this matter. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Cross-bridge movement in rat cardiac muscle as a function of calcium concentration.

    PubMed Central

    Matsubara, I; Maughan, D W; Saeki, Y; Yagi, N

    1989-01-01

    1. By applying the X-ray diffraction method to chemically skinned papillary muscles of the rat, the transfer of myosin heads from the thick to the thin filaments was studied as a function of Ca2+ concentration. 2. No significant transfer of the heads occurred when the Ca2+ concentration was below the threshold of contraction (pCa 6.2). 3. During the maximum isometric contraction at pCa 4.4, 80% of the myosin heads were transferred to the thin filament. 4. When the muscle was activated isometrically at low Ca2+ concentrations (pCa 6.2-5.8), where the average tension was less than 20% of the maximum, a disproportionately large number of myosin heads were transferred to the thin filament. 5. It was concluded that a significant fraction of the heads transferred at the low Ca2+ concentrations does not produce tension. PMID:2621610

  14. Calcium-induced movement of troponin-I relative to actin in skeletal muscle thin filaments.

    PubMed

    Tao, T; Gong, B J; Leavis, P C

    1990-03-16

    The role of troponin-I (the inhibitory subunit of troponin) in the regulation by Ca2+ of skeletal muscle contraction was investigated with resonance energy transfer and photo cross-linking techniques. The effect of Ca2+ on the proximity of troponin-I to actin in reconstituted rabbit skeletal thin filaments was determined. The distance between the cysteine residue at position 133 (Cys133) of troponin-I and Cys374 of actin increases by approximately 15 angstroms on binding of Ca2+ to troponin-C. Also, troponin-I labeled at Cys133 with benzophenone-4-maleimide could be photo cross-linked to actin in the absence of Ca2+, but not in its presence. These results suggest that troponin-I is attached to actin in the Ca2(+)-free or relaxed state of muscle, and that it detaches from actin on Ca2+ activation of contraction. Thus, troponin-I may function as a Ca2(+)-dependent molecular switch in regulation of skeletal muscle contraction.

  15. Pain-Related Brain Activity Evoked by Active and Dynamic Arm Movement: Delayed-Onset Muscle Soreness as a Promising Model for Studying Movement-Related Pain in Humans

    PubMed Central

    Matsuda, Yoichi; Kan, Shigeyuki; Uematsu, Hironobu; Shibata, Masahiko; Fujino, Yuji

    2015-01-01

    Objective To demonstrate delayed-onset muscle soreness (DOMS) is a suitable model for the study of movement-evoked pain, we attempted to identify brain regions specifically involved in pain evoked by active and dynamic movement under DOMS condition. Subject Twelve healthy volunteers Methods DOMS was induced in the left upper-arm flexor muscles by an eccentric elbow contraction exercise. Movement-evoked pain in the affected muscles was evaluated just before (day 0) and after (days 1–7 and 30) the exercise using a visual analog scale. Subjects underwent functional magnetic resonance imaging scans while performing repeated elbow flexion on day 2 (DOMS condition) and day 30 (painless condition). We compared brain activity between the DOMS and painless conditions. Results Movement-evoked pain reached peak intensity on day 2 and disappeared by day 30 in all subjects. No subject felt pain at rest on either of these days. Contralateral primary motor cortex (M1), parietal operculum and bilateral presupplementary motor area (pre-SMA) showed greater activity during active and dynamic arm movement with DOMS than during the same movement without pain. There was no difference in activation of brain regions known collectively as the “pain matrix,” except for the parietal operculum, between the two conditions. Conclusion Active and dynamic movement with pain selectively evoked activation of M1, pre-SMA, and parietal operculum, as assessed using DOMS. Our results demonstrate that DOMS is a promising experimental model for the study of movement-evoked pain in humans. PMID:25929675

  16. Dynamic modeling of the neck muscles during horizontal head movement. Part II: Model construction in Pro/Engineer.

    PubMed

    Haapala, Stephenie A; Enderle, John D

    2003-01-01

    This paper describes the next phase of research on a parametric model of the head-neck system for dynamic simulation of horizontal head rotation. A skull has been imported into Pro/Engineer software and has been assigned mass properties such as density, surface area and moments of inertia. The origin of a universal coordinate system has been located at the center of gravity of the T1 vertebrae. Identification of this origin allows insertion and attachment points of the sternocleidomastoid (SCOM) and splenius capitis to be located. An assembly has been created, marking the location of both muscle sets. This paper will also explore the obstacles encountered when working with an imported feature in Pro/E and attempts to resolve some of these issues. The goal of this work involves the creation of a 3D homeomorphic saccadic eye and head movement system.

  17. Construction of standardized Arabic questionnaires for screening neurological disorders (dementia, stroke, epilepsy, movement disorders, muscle and neuromuscular junction disorders)

    PubMed Central

    El Tallawy, Hamdy N; Farghaly, Wafaa MA; Rageh, Tarek A; Saleh, Ahmed O; Mestekawy, Taha AH; Darwish, Manal MM; Abd El Hamed, Mohamed A; Ali, Anwar M; Mahmoud, Doaa M

    2016-01-01

    A screening questionnaire is an important tool for early diagnosis of neurological disorders, and for epidemiological research. This screening instrument must be both feasible and valid. It must be accepted by the community and must be sensitive enough. So, the aim of this study was to prepare different Arabic screening questionnaires for screening different neurological disorders. This study was carried out in three stages. During the first stage, construction of separate questionnaires designed for screening the five major neurological disorders: cerebrovascular stroke, dementias, epilepsy, movement disorders, and muscle and neuromuscular disorders were done. Validation of the screening questionnaires was carried out in the second stage. Finally, questionnaire preparation was done in the third stage. Questions with the accepted sensitivity and specificity in each questionnaire formed the refined separate questionnaires. PMID:27621635

  18. A quantitative analysis of the submentalis muscle electromyographic amplitude during rapid eye movement sleep across the lifespan.

    PubMed

    Ferri, Raffaele; Bruni, Oliviero; Fulda, Stephany; Zucconi, Marco; Plazzi, Giuseppe

    2012-06-01

    The current definition of rapid eye movement (REM) sleep without atonia has no quantitative character, and cut-off values above which the level of electromyographic tone can be considered to be 'excessive' are unclear. The aim of this study was to analyse the characteristics of chin electromyographic amplitude by means of an automatic approach in a large group of normal controls, subdivided into different age groups. Eighty-eight normal controls were included, subdivided into six age groups: preschoolers (≤6 years); schoolers (6-10 years); preadolescents (10-13 years); young adults (24-40 years); middle-aged (58-65 years); and old (>65 years). The average amplitude of the rectified submentalis muscle electromyographic signal was used for the computation of the REM sleep Atonia Index. Chin muscle activations were detected, and their amplitude, duration and interval analysed. REM sleep Atonia Index showed a progressive and rapid increase from the preschool age to school and preadolescent age, reaching the maximum in the young adult group; after this age a small decline was observed in the middle-aged and old subjects. Conversely, the number of movements per hour in REM sleep showed a 'U'-shaped distribution across these age groups, with the minimum in the preadolescent group and the two extremes (preschool age and old) showing similar average levels of activity. Our results show that REM sleep atonia develops continuously during the lifespan, and undergoes complex changes with different developmental trajectories for REM atonia and electromyographic activations during REM sleep. Different mechanisms might subserve these two phenomena and their differential developmental dynamics.

  19. Voluntary and involuntary running in the rat show different patterns of theta rhythm, physical activity, and heart rate.

    PubMed

    Li, Jia-Yi; Kuo, Terry B J; Yen, Jiin-Cherng; Tsai, Shih-Chih; Yang, Cheryl C H

    2014-05-01

    Involuntarily exercising rats undergo more physical and mental stress than voluntarily exercising rats; however, these findings still lack electrophysiological evidence. Many studies have reported that theta rhythm appears when there is mental stress and that it is affected by emotional status. Thus we hypothesized that the differences between voluntary and involuntary movement should also exist in the hippocampal theta rhythm. Using the wheel and treadmill exercise models as voluntary and involuntary exercise models, respectively, this study wirelessly recorded the hippocampal electroencephalogram, electrocardiogram, and three-dimensional accelerations of young male rats. Treadmill and wheel exercise produced different theta patterns in the rats before and during running. Even though the waking baselines for the two exercise types were recorded in different environments, there did not exist any significant difference after distinguishing the rats' sleep/wake status. When the same movement-related parameters are considered, the treadmill running group showed more changes in their theta frequency (4-12 Hz), in their theta power between 9.5-12 Hz, and in their heart rate than the wheel running group. A positive correlation between the changes in high-frequency (9.5-12 Hz) theta power and heart rate was identified. Our results reveal various voluntary and involuntary changes in hippocampal theta rhythm as well as divergences in heart rate and high-frequency theta activity that may represent the effects of an additional emotional state or the sensory interaction during involuntary running by rats.

  20. Decoding Lower Limb Muscle Activity and Kinematics from Cortical Neural Spike Trains during Monkey Performing Stand and Squat Movements

    PubMed Central

    Ma, Xuan; Ma, Chaolin; Huang, Jian; Zhang, Peng; Xu, Jiang; He, Jiping

    2017-01-01

    Extensive literatures have shown approaches for decoding upper limb kinematics or muscle activity using multichannel cortical spike recordings toward brain machine interface (BMI) applications. However, similar topics regarding lower limb remain relatively scarce. We previously reported a system for training monkeys to perform visually guided stand and squat tasks. The current study, as a follow-up extension, investigates whether lower limb kinematics and muscle activity characterized by electromyography (EMG) signals during monkey performing stand/squat movements can be accurately decoded from neural spike trains in primary motor cortex (M1). Two monkeys were used in this study. Subdermal intramuscular EMG electrodes were implanted to 8 right leg/thigh muscles. With ample data collected from neurons from a large brain area, we performed a spike triggered average (SpTA) analysis and got a series of density contours which revealed the spatial distributions of different muscle-innervating neurons corresponding to each given muscle. Based on the guidance of these results, we identified the locations optimal for chronic electrode implantation and subsequently carried on chronic neural data recordings. A recursive Bayesian estimation framework was proposed for decoding EMG signals together with kinematics from M1 spike trains. Two specific algorithms were implemented: a standard Kalman filter and an unscented Kalman filter. For the latter one, an artificial neural network was incorporated to deal with the nonlinearity in neural tuning. High correlation coefficient and signal to noise ratio between the predicted and the actual data were achieved for both EMG signals and kinematics on both monkeys. Higher decoding accuracy and faster convergence rate could be achieved with the unscented Kalman filter. These results demonstrate that lower limb EMG signals and kinematics during monkey stand/squat can be accurately decoded from a group of M1 neurons with the proposed

  1. Decoding Lower Limb Muscle Activity and Kinematics from Cortical Neural Spike Trains during Monkey Performing Stand and Squat Movements.

    PubMed

    Ma, Xuan; Ma, Chaolin; Huang, Jian; Zhang, Peng; Xu, Jiang; He, Jiping

    2017-01-01

    Extensive literatures have shown approaches for decoding upper limb kinematics or muscle activity using multichannel cortical spike recordings toward brain machine interface (BMI) applications. However, similar topics regarding lower limb remain relatively scarce. We previously reported a system for training monkeys to perform visually guided stand and squat tasks. The current study, as a follow-up extension, investigates whether lower limb kinematics and muscle activity characterized by electromyography (EMG) signals during monkey performing stand/squat movements can be accurately decoded from neural spike trains in primary motor cortex (M1). Two monkeys were used in this study. Subdermal intramuscular EMG electrodes were implanted to 8 right leg/thigh muscles. With ample data collected from neurons from a large brain area, we performed a spike triggered average (SpTA) analysis and got a series of density contours which revealed the spatial distributions of different muscle-innervating neurons corresponding to each given muscle. Based on the guidance of these results, we identified the locations optimal for chronic electrode implantation and subsequently carried on chronic neural data recordings. A recursive Bayesian estimation framework was proposed for decoding EMG signals together with kinematics from M1 spike trains. Two specific algorithms were implemented: a standard Kalman filter and an unscented Kalman filter. For the latter one, an artificial neural network was incorporated to deal with the nonlinearity in neural tuning. High correlation coefficient and signal to noise ratio between the predicted and the actual data were achieved for both EMG signals and kinematics on both monkeys. Higher decoding accuracy and faster convergence rate could be achieved with the unscented Kalman filter. These results demonstrate that lower limb EMG signals and kinematics during monkey stand/squat can be accurately decoded from a group of M1 neurons with the proposed

  2. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  3. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  4. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  5. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  6. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  7. 32 CFR 644.102 - Examples of involuntary acquisitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Examples of involuntary acquisitions. 644.102 Section 644.102 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Acquisition Involuntary Acquisition by the United States § 644.102 Examples...

  8. 43 CFR 426.14 - Involuntary acquisition of land.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Involuntary acquisition of land. 426.14 Section 426.14 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR ACREAGE LIMITATION RULES AND REGULATIONS § 426.14 Involuntary acquisition of land...

  9. 43 CFR 426.14 - Involuntary acquisition of land.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Involuntary acquisition of land. 426.14 Section 426.14 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR ACREAGE LIMITATION RULES AND REGULATIONS § 426.14 Involuntary acquisition of land...

  10. 43 CFR 426.14 - Involuntary acquisition of land.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Involuntary acquisition of land. 426.14 Section 426.14 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR ACREAGE LIMITATION RULES AND REGULATIONS § 426.14 Involuntary acquisition of land...

  11. Gender Differences in Coping with Involuntary White Collar Job Loss.

    ERIC Educational Resources Information Center

    Eby, Lillian T.; Buch, Kimberly

    Corporate restructuring has resulted in involuntary job loss for a significant number of white collar workers. This study investigated gender differences in reaction to involuntary job loss and tested a model of career gorwth through job loss. Former clients, 456 males and 62 females, of a nationwide outplacement firm completed a questionnaire…

  12. 12 CFR 1263.27 - Involuntary termination of membership.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Involuntary termination of membership. 1263.27... BANKS Withdrawal and Removal From Membership § 1263.27 Involuntary termination of membership. (a) Grounds. The board of directors of a Bank may terminate the membership of any institution that: (1)...

  13. 12 CFR 1263.27 - Involuntary termination of membership.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 9 2013-01-01 2013-01-01 false Involuntary termination of membership. 1263.27... BANKS Withdrawal and Removal From Membership § 1263.27 Involuntary termination of membership. (a) Grounds. The board of directors of a Bank may terminate the membership of any institution that: (1)...

  14. 12 CFR 1263.27 - Involuntary termination of membership.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 10 2014-01-01 2014-01-01 false Involuntary termination of membership. 1263.27... BANKS Withdrawal and Removal From Membership § 1263.27 Involuntary termination of membership. (a) Grounds. The board of directors of a Bank may terminate the membership of any institution that: (1)...

  15. 12 CFR 925.27 - Involuntary termination of membership.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Involuntary termination of membership. 925.27... ASSOCIATES MEMBERS OF THE BANKS Withdrawal and Removal From Membership § 925.27 Involuntary termination of membership. (a) Grounds. The board of directors of a Bank may terminate the membership of any...

  16. Relationship between frequency of involuntary autobiographical memories and cognitive failure.

    PubMed

    Kamiya, Shunji

    2014-01-01

    Involuntary autobiographical memories are memories of personal experiences that pop into mind without a conscious attempt at their retrieval. This study investigated individual differences in the number of involuntary autobiographical memories, and explored the relationship between the frequency of occurrence in involuntary autobiographical memory and cognitive failures in everyday memory, as indexed by metamemory questionnaires. A total of 24 undergraduate students reported involuntary autobiographical memories in controlled field interviews, and completed the Everyday Memory Questionnaire and the Cognitive Failures Questionnaire. The results showed that, despite controlled conditions, considerable individual differences were observed in the number of involuntary autobiographical memories reported while walking along a prescribed route on the campus, and that reported memories were predominantly serving self function. In addition, the number of involuntary autobiographical memories was positively related to cognitive failures in everyday memory: participants who acknowledged more problems in everyday memory had a higher frequency of involuntary memories. The implications of these results are discussed in terms of the complementary function of involuntary autobiographical memory in everyday life.

  17. When Leaders Are Challenged: Dealing with Involuntary Members in Groups

    ERIC Educational Resources Information Center

    Schimmel, Christine J.; Jacobs, E.

    2011-01-01

    Leading groups can be challenging and difficult. Leading groups in which members are involuntary and negative increases the level of difficulty and creates new dynamics in the group leading process. This article proposes specific skills and strategies for dealing with three specific issues related to involuntary members in groups: groups where all…

  18. 29 CFR 1625.9 - Prohibition of involuntary retirement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 4 2013-07-01 2013-07-01 false Prohibition of involuntary retirement. 1625.9 Section 1625... DISCRIMINATION IN EMPLOYMENT ACT Interpretations § 1625.9 Prohibition of involuntary retirement. (a)(1) As... the terms of a bona fide seniority system or any bona fide employee benefit plan such as a...

  19. 29 CFR 1625.9 - Prohibition of involuntary retirement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 4 2014-07-01 2014-07-01 false Prohibition of involuntary retirement. 1625.9 Section 1625... DISCRIMINATION IN EMPLOYMENT ACT Interpretations § 1625.9 Prohibition of involuntary retirement. (a)(1) As... the terms of a bona fide seniority system or any bona fide employee benefit plan such as a...

  20. Repeated tongue lift movement induces neuroplasticity in corticomotor control of tongue and jaw muscles in humans.

    PubMed

    Komoda, Yoshihiro; Iida, Takashi; Kothari, Mohit; Komiyama, Osamu; Baad-Hansen, Lene; Kawara, Misao; Sessle, Barry; Svensson, Peter

    2015-11-19

    This study investigated the effect of repeated tongue lift training (TLT) on the excitability of the corticomotor representation of the human tongue and jaw musculature. Sixteen participants performed three series of TLT for 41 min on each of 5 consecutive days. Each TLT series consisted of two pressure levels (5 kPa and 10 kPa). All participants underwent transcranial magnetic stimulation (TMS) and electromyographic (EMG) recordings of motor evoked potentials (MEPs) in four sessions: (1) before TLT on Day 1 (baseline), (2) after TLT on Day 1, (3) before TLT on Day 5, and (4) after TLT on Day 5. EMG recordings from the left and right tongue dorsum and masseter muscles were made at three pressure levels (5 kPa, 10 kPa, 100% tongue lift), and tongue, masseter, and first dorsal interosseous (FDI) MEPs were measured. There were no significant day-to-day differences in the tongue pressure during maximum voluntary contractions. The amplitudes and thresholds of tongue and masseter MEPs after TLT on Day 5 were respectively higher and lower than before TLT on Day 1 (P<0.005), and there was also a significant increase in tongue and masseter MEP areas; no significant changes occurred in MEP onset latencies. FDI MEP parameters (amplitude, threshold, area, latency) were not significantly different between the four sessions. Our findings suggest that repeated TLT can trigger neuroplasticity reflected in increased excitability of the corticomotor representation of not only the tongue muscles but also the masseter muscles. Copyright © 2015. Published by Elsevier B.V.

  1. Neck and shoulder muscle activity and thorax movement in singing and speaking tasks with variation in vocal loudness and pitch.

    PubMed

    Pettersen, Viggo; Bjørkøy, Kåre; Torp, Hans; Westgaard, Rolf Harald

    2005-12-01

    The aim of this study was to examine respiratory phasing and loading levels of sternocleidomastoideus (STM), scalenus (SC), and upper trapezius (TR) muscles in vocalization tasks with variation in vocal loudness and pitch. Eight advanced singing students, aged 22 to 28 years, participated. Surface electromyographic (EMG) activity was recorded from STM, SC, and TR. Thorax movement was detected by two strain gauge sensors placed around the upper (upper TX) and lower (lower TX) thorax. A glissando and simplified singing and speaking tasks were performed. Sustained vowels /a:-i-ae-o:/ were sung in a glissando from lowest to highest pitch (mixed voice/falsetto) back to lowest pitch and in short singing sequences at comfortable, low, and high pitches. The same vowels were spoken softly and loudly for about the same length. The subjects inhaled between the vowels. It was concluded that the inspiratory phased STM and SC muscles produced a counterforce to compression of upper TX at high pitches in glissando. STM and SC were activated to higher levels during phonation than in inhalation. As breathing demands were reduced, STM and SC activity was lowered and the respiratory phasing of peak amplitude changed to inhalation. TR contributed to exhalation in demanding singing with long breathing cycles, but it was less active in singing tasks with short breathing cycles and was essentially inactive in simplified speaking tasks.

  2. Alteration of Contractile Function and Calcium Ion Movements in Vascular Smooth Muscle by Gentamicin and Other Aminoglycoside Antibiotics

    PubMed Central

    Adams, H. Richard; Goodman, Frank R.; Weiss, George B.

    1974-01-01

    Experiments were conducted to examine the effects of certain aminoglycoside antibiotics on contractile responses and related calcium ion (Ca2+) movements in isolated vascular smooth muscle. Gentamicin, kanamycin, and streptomycin decreased contractile responses produced by norepinephrine, histamine, and high K+ in rabbit aortic strips. The inhibitory action of these antibiotics on mechanical function was more pronounced when the Ca2+ concentration of the bathing solution was decreased from 1.5 mM (normal Ca2+ solution) to 0.05 mM (low Ca2+ solution). The uptake of radiocalcium (45Ca) into the isolated media-intimal layer of rabbit aortae was decreased in a maintained manner by each antibiotic. With gentamicin, the inhibitory effect on 45Ca uptake was shown to be dependent upon the concentration of gentamicin employed and to be more evident in a 0.1 mM Ca2+ solution than in a normal Ca2+ solution. In addition, the rate of 45Ca efflux from the rabbit aortic media-intimal layer was increased in a sustained manner by gentamicin, streptomycin, and kanamycin. Furthermore, contractile responses induced by high K+ and norepinephrine in canine carotid arterial strips were inhibited by gentamicin. Present findings indicate that aminoglycoside antibiotics interfere with Ca2+-linked events leading to activation of the contractile mechanism of vascular smooth muscle. These in vitro findings may partially explain the occurrence of in vivo cardiovascular depression that has occasionally been observed after the administration of chemically related antimicrobial agents. PMID:15825418

  3. Effects of moderate-velocity strength training on peak muscle power and movement velocity: do women respond differently than men?

    PubMed

    Delmonico, Matthew J; Kostek, Matthew C; Doldo, Neil A; Hand, Brian D; Bailey, Jason A; Rabon-Stith, Karma M; Conway, Joan M; Carignan, Craig R; Lang, Jesse; Hurley, Ben F

    2005-11-01

    The effects of a 10-wk unilateral knee extension strength training (ST) program on peak power (PP) and peak movement velocity (PV), at given absolute (force load) and relative (same % of 1 repetition maximum) resistances (loads), were examined in 30 older men [64 yr (7 SD)] and 32 older women [62 yr (6 SD)]. PP increased significantly in both men and women at the same absolute (P < 0.001) and relative loads (P < 0.01) with ST. Men had a significantly greater increase in relative PP than women with ST at 60% (P < 0.01) and 70% (P < 0.001) of 1 repetition maximum when covarying for baseline differences and age. However, when each subject was tested at the same absolute load and when PP was normalized for the muscle volume of the trained knee extensors (i.e., absolute muscle power quality), women increased by 9% (P < 0.05), whereas men did not change. Both men and women increased their absolute PV (P < 0.001) but decreased their relative PV significantly with ST (P < 0.05). However, when baseline values and age were covaried, women had significantly less of a decrease in relative PV quality with ST than men (P < 0.01), although the difference was small. These normalized data suggest that ST-induced increases in PP depend on muscular hypertrophy in men, but not in women, providing further support for the hypothesis developed from our previous report (Ivey FM, Tracy BL, Lemmer JT, NessAiver M, Metter EJ, Fozard JL and Hurley BF. J Gerontol A Biol Sci Med Sci 55: B152-B157, 2000) that improvements in muscle function with ST result from nonmuscle mass adaptations to a greater extent in women than men.

  4. Intracellular diffusion in the presence of mobile buffers. Application to proton movement in muscle.

    PubMed Central

    Irving, M; Maylie, J; Sizto, N L; Chandler, W K

    1990-01-01

    Junge and McLaughlin (1987) derived an expression for the apparent diffusion constant of protons in the presence of both mobile and immobile buffers. Their derivation applies only to cases in which the values of pH are considerably greater than the largest pK of the individual buffers, a condition that is not expected to hold in skeletal muscle or many other cell types. Here we show that, if the pH gradients are small, the same expression for the apparent diffusion constant of protons can be derived without such constraints on the values of the pK's. The derivation is general and can be used to estimate the apparent diffusion constant of any substance that diffuses in the presence of both mobile and immobile buffers. The apparent diffusion constant of protons is estimated to be 1-2 x 10(-6) cm2/s at 18 degrees C inside intact frog twitch muscle fibers. It may be smaller inside cut fibers, owing to a reduction in the concentration of mobile myoplasmic buffers, so that in this preparation a pH gradient, if established within a sarcomere following action potential stimulation, could last 10 ms or longer after stimulation ceased. PMID:2160843

  5. Myosin head movements are synchronous with the elementary force-generating process in muscle

    NASA Astrophysics Data System (ADS)

    Irving, Malcolm; Lombardi, Vincenzo; Piazzesi, Gabriella; Ferenczi, Michael A.

    1992-05-01

    MOTOR proteins such as myosin, dynein and kinesin use the free energy of ATP hydrolysis to produce force or motion, but despite recent progress1-4 their molecular mechanism is unknown. The best characterized system is the myosin motor which moves actin filaments in muscle5-12. When an active muscle fibre is rapidly shortened the force first decreases, then partially recovers over the next few milliseconds5. This elementary force-generating process is thought to be due to a structural 'working stroke' in the myosin head domain5-9, although structural studies have not provided definitive support for this10-12. X-ray diffraction has shown that shortening steps produce a large decrease in the intensity of the 14.5 nm reflection arising from the axial repeat of the myosin heads along the filaments13,14. This was interpreted as a structural change at the end of the working stroke, but the techniques then available did not allow temporal resolution of the elementary force-generating process itself. Using improved measurement techniques, we show here that myosin heads move by about 10 nm with the same time course as the elementary force-generating process.

  6. Effects of eccentric strength training on biceps femoris muscle architecture and knee joint range of movement.

    PubMed

    Potier, Tara G; Alexander, Caroline M; Seynnes, Olivier R

    2009-04-01

    The aim was to determine whether eccentric strengthening changed the muscle architecture of human biceps femoris and consequently, knee range of motion. Twenty-two subjects were randomly assigned to control and experimental groups. The experimental group completed an eccentric strengthening programme for 8 weeks. Outcome measures included hamstring muscle strength (one repetition maximum), the passive knee extension test (PKE) (knee joint angle at which the onset of passive tension occurs), fascicle length (FL) and pennation angle (PA). One repetition maximum increased by 34% (P < 0.01), the PKE test revealed a 5% increase in joint range of motion (P = 0.01), FL increased by 34% (P = 0.01) and PA did not change (P = 0.38). This is the first report of an increase in FL in the biceps femoris following eccentric resistance training. In addition, the results might imply that this fascicle lengthening could lead to an increase in the range of motion of the knee. Clinical implications for rehabilitation and injury prevention are discussed.

  7. Implications of movement-related cortical potential for understanding neural adaptations in muscle strength tasks.

    PubMed

    Lattari, Eduardo; Arias-Carrión, Oscar; Monteiro-Junior, Renato Sobral; Mello Portugal, Eduardo Matta; Paes, Flávia; Menéndez-González, Manuel; Silva, Adriana Cardoso; Nardi, Antonio Egidio; Machado, Sergio

    2014-03-06

    This systematic review aims to provide information about the implications of the movement-related cortical potential (MRCP) in acute and chronic responses to the counter resistance training. The structuring of the methods of this study followed the proposals of the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses). It was performed an electronically search in Pubmed/Medline and ISI Web of Knowledge data bases, from 1987 to 2013, besides the manual search in the selected references. The following terms were used: Bereitschaftspotential, MRCP, strength and force. The logical operator "AND" was used to combine descriptors and terms used to search publications. At the end, 11 studies attended all the eligibility criteria and the results demonstrated that the behavior of MRCP is altered because of different factors such as: force level, rate of force development, fatigue induced by exercise, and the specific phase of muscular action, leading to an increase in the amplitude in eccentric actions compared to concentric actions, in acute effects. The long-term adaptations demonstrated that the counter resistance training provokes an attenuation in the amplitude in areas related to the movement, which may be caused by neural adaptation occurred in the motor cortex.

  8. Implications of movement-related cortical potential for understanding neural adaptations in muscle strength tasks

    PubMed Central

    2014-01-01

    This systematic review aims to provide information about the implications of the movement-related cortical potential (MRCP) in acute and chronic responses to the counter resistance training. The structuring of the methods of this study followed the proposals of the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses). It was performed an electronically search in Pubmed/Medline and ISI Web of Knowledge data bases, from 1987 to 2013, besides the manual search in the selected references. The following terms were used: Bereitschaftspotential, MRCP, strength and force. The logical operator “AND” was used to combine descriptors and terms used to search publications. At the end, 11 studies attended all the eligibility criteria and the results demonstrated that the behavior of MRCP is altered because of different factors such as: force level, rate of force development, fatigue induced by exercise, and the specific phase of muscular action, leading to an increase in the amplitude in eccentric actions compared to concentric actions, in acute effects. The long-term adaptations demonstrated that the counter resistance training provokes an attenuation in the amplitude in areas related to the movement, which may be caused by neural adaptation occurred in the motor cortex. PMID:24602228

  9. Managing Lower Extremity Muscle Tone and Function in Children with Cerebral Palsy via Eight-Week Repetitive Passive Knee Movement Intervention

    ERIC Educational Resources Information Center

    Cheng, Hsin-Yi Kathy; Ju, Yan-Ying; Chen, Chia-Ling; Chang, Ya-Ju; Wong, Alice May-Kuen

    2013-01-01

    This study used a repeated measures design to assess the effect of an eight-week repetitive passive movement (RPM) intervention on lower extremity muscle tone and function in children with cerebral palsy (CP). Eighteen children (aged 9.5 [plus or minus] 2.1 years) with spastic CP were randomly assigned to a knee RPM intervention condition of 3…

  10. Managing Lower Extremity Muscle Tone and Function in Children with Cerebral Palsy via Eight-Week Repetitive Passive Knee Movement Intervention

    ERIC Educational Resources Information Center

    Cheng, Hsin-Yi Kathy; Ju, Yan-Ying; Chen, Chia-Ling; Chang, Ya-Ju; Wong, Alice May-Kuen

    2013-01-01

    This study used a repeated measures design to assess the effect of an eight-week repetitive passive movement (RPM) intervention on lower extremity muscle tone and function in children with cerebral palsy (CP). Eighteen children (aged 9.5 [plus or minus] 2.1 years) with spastic CP were randomly assigned to a knee RPM intervention condition of 3…

  11. Intracellular calcium movements during relaxation and recovery of superfast muscle fibers of the toadfish swimbladder

    PubMed Central

    Nelson, Frank E.; Hollingworth, Stephen; Rome, Lawrence C.

    2014-01-01

    The mating call of the Atlantic toadfish is generated by bursts of high-frequency twitches of the superfast twitch fibers that surround the swimbladder. At 16°C, a calling period can last several hours, with individual 80–100-Hz calls lasting ∼500 ms interleaved with silent periods (intercall intervals) lasting ∼10 s. To understand the intracellular movements of Ca2+ during the intercall intervals, superfast fibers were microinjected with fluo-4, a high-affinity fluorescent Ca2+ indicator, and stimulated by trains of 40 action potentials at 83 Hz, which mimics fiber activity during calling. The fluo-4 fluorescence signal was measured during and after the stimulus trains; the signal was also simulated with a kinetic model of the underlying myoplasmic Ca2+ movements, including the binding and transport of Ca2+ by the sarcoplasmic reticulum (SR) Ca2+ pumps. The estimated total amount of Ca2+ released from the SR during a first stimulus train is ∼6.5 mM (concentration referred to the myoplasmic water volume). At 40 ms after cessation of stimulation, the myoplasmic free Ca2+ concentration ([Ca2+]) is below the threshold for force generation (∼3 µM), yet the estimated concentration of released Ca2+ remaining in the myoplasm (Δ[CaM]) is large, ∼5 mM, with ∼80% bound to parvalbumin. At 10 s after stimulation, [Ca2+] is ∼90 nM (three times the assumed resting level) and Δ[CaM] is ∼1.3 mM, with 97% bound to parvalbumin. Ca2+ movements during the intercall interval thus appear to be strongly influenced by (a) the accumulation of Ca2+ on parvalbumin and (b) the slow rate of Ca2+ pumping that ensues when parvalbumin lowers [Ca2+] near the resting level. With repetitive stimulus trains initiated at 10-s intervals, Ca2+ release and pumping come quickly into balance as a result of the stability (negative feedback) supplied by the increased rate of Ca2+ pumping at higher [Ca2+]. PMID:24733838

  12. The association between involuntary memory and emotional adjustment after childbirth.

    PubMed

    Briddon, Emma; Isaac, Claire; Slade, Pauline

    2015-11-01

    A woman's memory of her experience of giving birth can strongly influence her mental health, and the development of her relationship with her infant, in a positive or negative direction. Highly distressing, involuntary memories of the birth may indicate symptoms of post-traumatic stress (PTS), which is increasingly recognized as a possible outcome of childbirth. Involuntary memories are not, however, exclusive to trauma and can also be experienced after positive events. This study sought to investigate involuntary memories for childbirth, as this is an event that is known to be potentially experienced both as highly positive and negative, and associated with a range of emotional outcomes, including greater well-being and symptoms of PTS. A total of 122 women completed a measure of their emotional experience of giving birth within 3 days of the event, and 65 of these women responded to a postal follow-up at 6 weeks, with measures of involuntary memory experience, PTS symptoms and well-being. Experiencing pleasant involuntary memories was more common than experiencing unpleasant involuntary memories of the birth. The frequency of these memories and how they were experienced as either distressing or enjoyable was associated with post-partum emotional adjustment, demonstrated by the development of PTS symptoms or greater well-being. These results are important because to date, little research has examined the development of positive involuntary memories and their association with positive emotional adjustment. Statement of contribution What is already known on this subject? Positive and negative emotional experiences can coexist in childbirth. Involuntary memories after negative events can be associated with post-traumatic stress. Involuntary memories can also occur after strongly positive events. What does this study add? Women can experience both positive and negative involuntary memories after childbirth. Involuntary negative memories mediate the link between birth

  13. [Involuntary commitment: implication for psychiatric nursing practice].

    PubMed

    Moreira, Lilian Hortale de Oliveira; Loyola, Cristina Maria Douat

    2011-06-01

    The characteristics of involuntary psychiatric commitment (IPI) may cause implications on the nursing/patient relationship. The objectives of this study were to list the forms of nursing care delivered to psychiatric patients, according to the type of commitment; analyze the reaction of the nursing team towards the IPI patient, and discuss on the implications that IPI have on the practice o psychiatric nursing. A field research was performed with the nursing team of a psychiatric institution in Rio de Janeiro. After 50 hours of participant observation and 9 of focal group meetings, we found that the teams are concerned with the clinical evolution of the patients. No references of the nursing team to the IPI patient were observed. There are no records or actions of any kind that would suggest a specific look towards this type of patient. Nursing professionals are not able to clearly identify this type of patient, thus the care is provided as per the patient's needs or requests.

  14. Involuntary attentional capture by abrupt onsets

    NASA Technical Reports Server (NTRS)

    Remington, Roger W.; Johnston, James C.; Yantis, Steven

    1992-01-01

    Five experiments were carried out to examine the extent to which brief abrupt-onset visual stimuli involuntarily capture spatial attention. A fundumantal limitation on the conscious control of spatial attention is demonstrated. Data obtained reveal conditions under which the control of spatial attention is completely involuntary: attention is captured by an irrelevant event despite subjects' intentions to ignore the event. The paradigm used provided strong incentives to ignore the distracting abrupt onset, but these were insufficient to prevent capture. Results suggest that voluntary control of attention is limited to focusing attention in advance on locations, objects, or properties of interest. Under appropriate conditions, spatial attention can be involantarily drawn to abrupt-onset events despite the intention of subjects' to ignore them.

  15. Involuntary attentional capture by abrupt onsets

    NASA Technical Reports Server (NTRS)

    Remington, Roger W.; Johnston, James C.; Yantis, Steven

    1992-01-01

    Five experiments were carried out to examine the extent to which brief abrupt-onset visual stimuli involuntarily capture spatial attention. A fundumantal limitation on the conscious control of spatial attention is demonstrated. Data obtained reveal conditions under which the control of spatial attention is completely involuntary: attention is captured by an irrelevant event despite subjects' intentions to ignore the event. The paradigm used provided strong incentives to ignore the distracting abrupt onset, but these were insufficient to prevent capture. Results suggest that voluntary control of attention is limited to focusing attention in advance on locations, objects, or properties of interest. Under appropriate conditions, spatial attention can be involantarily drawn to abrupt-onset events despite the intention of subjects' to ignore them.

  16. [Involuntary admission of addict during early pregnancy].

    PubMed

    Hondius, Adger J K; Stikker, Tineke E; Wennink, J M B Hanneke; Honig, Adriaan

    2012-01-01

    A 30-year-old cocaine-dependent woman was 16 weeks pregnant. Because of possible endangerment of the fetus, an involuntary provisional admission was authorized. Of particular interest is the application of the Dutch Act on Formal Admissions to Psychiatric Hospitals for the primary diagnosis 'addiction' and the fact that the fetus was regarded as a legal 'other'. In severe cases of addiction combined with pregnancy an earlier intervention is needed and arrangement of accelerated legal custody of the newborn before birth should be considered. For the protection of the unborn, we advocate a stricter application of the United Nations Convention on the Rights of the Child. Information for addicted women with preconception counselling can help prevent a compulsory admission.

  17. Involuntary coping mechanisms: a psychodynamic perspective

    PubMed Central

    Vaillant, George E.

    2011-01-01

    Coping responses to stress can be divided into three broad categories. The first coping category involves voluntarily mobilizing social supports. The second category involves voluntary coping strategies like rehearsing responses to danger. The third coping category, like fever and leukocytosis, is involuntary. It entails deploying unconscious homeostatic mechanisms that reduce the disorganizing effects of sudden stress, DSM-5 offers a tentative hierarchy of defenses, from psychotic to immature to mature. The 70-year prospective Study of Development at Harvard provides a clinical validation of this hierarchy Maturity of coping predicted psychosocial adjustment to aging 25 years later, and was associated with not developing symptoms of post-traumatic stress disorder after very severe WWII combat. PMID:22034454

  18. Passive leg movement enhances interstitial VEGF protein, endothelial cell proliferation, and eNOS mRNA content in human skeletal muscle.

    PubMed

    Hellsten, Ylva; Rufener, Nora; Nielsen, Jens J; Høier, Birgitte; Krustrup, Peter; Bangsbo, Jens

    2008-03-01

    The present study used passive limb movement as an experimental model to study the effect of increased blood flow and passive stretch, without enhanced metabolic demand, in young healthy male subjects. The model used was 90 min of passive movement of the leg leading to a 2.8-fold increase (P < 0.05) in blood flow without a significant enhancement in oxygen uptake. Muscle interstitial fluid was sampled with microdialysis technique and analyzed for vascular endothelial growth factor (VEGF) protein and for the effect on endothelial cell proliferation. Biopsies obtained from the musculus vastus lateralis were analyzed for mRNA content of VEGF, endothelial nitric oxide synthase (eNOS), and matrix metalloproteinase-2 (MMP-2). The passive leg movement caused an increase (P < 0.05) in interstitial VEGF protein concentration above rest (73 +/- 21 vs. 344 +/- 83 pg/ml). Addition of muscle dialysate to cultured endothelial cells revealed that dialysate obtained during leg movement induced a 3.2-fold higher proliferation rate (P < 0.05) than dialysate obtained at rest. Passive movement also enhanced (P < 0.05) the eNOS mRNA level fourfold above resting levels. VEGF mRNA and MMP-2 mRNA levels were unaffected. The results show that a session of passive leg movement, elevating blood flow and causing passive stretch, augments the interstitial concentrations of VEGF, the proliferative effect of interstitial fluid, and eNOS mRNA content in muscle tissue. We propose that enhanced blood flow and passive stretch are positive physiological stimulators of factors associated with capillary growth in human muscle.

  19. EMG discharge patterns during human grip movement are task-dependent and not modulated by muscle contraction modes: a transcranial magnetic stimulation (TMS) study.

    PubMed

    Anson, J G; Hasegawa, Y; Kasai, T; Latash, M L; Yahagi, S

    2002-05-03

    Our previous study revealed that, during tonic muscle contraction, remarkable functional differences among intrinsic and extrinsic muscles were observed during two different grip movements, i.e., precision and power grips. To verify whether this evidence is true even under the phasic muscle contraction, magnetic stimulation was delivered over the left scalp while a normal human subject performed phasic precision or power grip responses of the right-hand fingers in a simple reaction time (SRT) paradigm. Magnetic stimulation delivered during the latent period revealed different cortico-motoneuronal excitations between the two grip responses. In particular, the contributions of extensor carpi radialis (ECR) muscle were definitely different between the two grip responses, although motor-evoked potentials (MEPs) of first dorsal interosseous (FDI) prior to, and after EMG onset of movement initiation, were not different. These results were similar to previous results obtained during tonic muscle contraction. Thus, we have concluded that the task-dependent EMG discharge pattern in finger manipulation could not be modulated by muscle contraction modes.

  20. The effect of decompressive surgery on lumbar paraspinal and biceps brachii muscle function and movement perception in lumbar spinal stenosis: a 2-year follow-up.

    PubMed

    Kääriäinen, Tommi; Taimela, Simo; Aalto, Timo; Kröger, Heikki; Herno, Arto; Turunen, Veli; Savolainen, Sakari; Kankaanpää, Markku; Airaksinen, Olavi; Leinonen, Ville

    2016-03-01

    Chronic low back pain and lumbar spinal stenosis (LSS) seem to deteriorate lumbar muscle function and proprioception but the effect of surgery on them remains unclear. This study evaluates the effect of decompressive surgery on lumbar movement perception and paraspinal and biceps brachii (BB) muscle responses during sudden upper limb loading in LSS. Low back and radicular pain intensity (VAS) and Oswestry Disability Index (ODI) were measured together with lumbar proprioception and paraspinal and BB muscle responses prior to and 3 and 24 months after surgery in 30 LSS patients. Lumbar proprioception was assessed by a previously validated motorized trunk rotation unit and muscle responses for sudden upper limb loading by surface EMG. Lumbar perception threshold improved after surgery during 3-month follow-up (from 4.6° to 3.1°, P = 0.015) but tend to deteriorate again during 24 months (4.0°, P = 0.227). Preparatory paraspinal and BB muscle responses prior to sudden load as well as paraspinal muscle activation latencies after the load remained unchanged. Impaired lumbar proprioception seems to improve shortly after decompressive surgery but tends to deteriorate again with longer follow-up despite the sustaining favorable clinical outcome. The surgery did not affect either the feed-forward or the feed-back muscle function, which indicates that the abnormal muscle activity in LSS is at least partly irreversible.

  1. Primary Motor Cortex Activation during Action Observation of Tasks at Different Video Speeds Is Dependent on Movement Task and Muscle Properties

    PubMed Central

    Moriuchi, Takefumi; Matsuda, Daiki; Nakamura, Jirou; Matsuo, Takashi; Nakashima, Akira; Nishi, Keita; Fujiwara, Kengo; Iso, Naoki; Nakane, Hideyuki; Higashi, Toshio

    2017-01-01

    The aim of the present study was to investigate how the video speed of observed action affects the excitability of the primary motor cortex (M1), as assessed by the size of motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS). Twelve healthy subjects observed a video clip of a person catching a ball (Experiment 1: rapid movement) and another 12 healthy subjects observed a video clip of a person reaching to lift a ball (Experiment 2: slow movement task). We played each video at three different speeds (slow, normal and fast). The stimulus was given at two points of timing in each experiment. These stimulus points were locked to specific frames of the video rather than occurring at specific absolute times, for ease of comparison across different speeds. We recorded MEPs from the first dorsal interosseous muscle (FDI) and abductor digiti minimi muscle (ADM) of the right hand. MEPs were significantly different for different video speeds only in the rapid movement task. MEPs for the rapid movement task were higher when subjects observed an action played at slow speed than normal or fast speed condition. There was no significant change for the slow movement task. Video speed was effective only in the ADM. Moreover, MEPs in the ADM were significantly higher than in the FDI in a rapid movement task under the slow speed condition. Our findings suggest that the M1 becomes more excitable when subjects observe the video clip at the slow speed in a rapid movement, because they could recognize the elements of movement in others. Our results suggest the effects of manipulating the speed of the viewed task on the excitability of the M1 during passive observation differ depending on the type of movement task observed. It is likely that rehabilitation in the clinical setting will be more efficient if the video speed is changed to match the task’s characteristics. PMID:28163678

  2. Changes in illusory ankle movements induced by tendon vibrations during the delayed recovery phase of stretch-shortening cycle fatigue: an indirect study of muscle spindle sensitivity modifications.

    PubMed

    Regueme, S C; Barthèlemy, J; Gauthier, G M; Nicol, C

    2007-12-14

    This study examined the perceived movement velocity induced by tendon vibrations during the delayed recovery phase of a stretch-shortening cycle (SSC)-type exercise characterized by 2 to 4 days of neuromuscular and proprioceptive impairments. Seven subjects performed until exhaustion series of unilateral rebounds involving mostly the triceps surae muscle group. Fatigue effects were quantified for the exercised and non-exercised legs through muscle soreness and maximal voluntary plantarflexion test (MVC) performed immediately before (PRE) and after the SSC exercise, and repeated 2 days later (D2). At PRE and D2, mechanical vibrations at 40, 60, 80, 100, and 120 Hz were applied to distal tendons of the exercised ankle. For each vibration, the subjects had to reproduce the perceived movement velocity with the non-exercised ankle. According to previous studies, the sole exercised leg was characterized by a D2 peak of muscle soreness associated, in the MVC test, with significant decreases in maximal force and mean soleus muscle activity. As compared to the PRE test and in all subjects, the vibrations applied at D2 to the tendon of the fatigued ankle extensor muscles led to significant decreases in the perceived movement velocity at 80 and 100 Hz, but to an increased one at 40 Hz. In contrast, vibrations applied to the tendon of the non-fatigued ankle flexor muscle did not result in any significant change. These results suggest that the delayed recovery phase of SSC fatigue is characterized by changes in muscle proprioception, which may partly result from a decreased sensitivity of the primary endings.

  3. Postural adjustments in arm and leg muscles associated with isodirectional and antidirectional coupling of upper limb movements in the horizontal plane.

    PubMed

    Baldissera, Fausto; Rota, Viviana; Esposti, Roberto

    2008-09-01

    The hypothesis that anticipatory postural adjustments (APAs) may concur in generating the directional preference experienced during limb coupled movements was tested by measuring the electromyographic and mechanic postural actions elicited when moving: (1) one single arm/hand and, (2) both limbs, iso- or antidirectionally coupled. During fast adduction of the right arm in the horizontal plane (prime mover, pectoralis Major, R: PM) APAs were recorded in the contralateral L: PM as well as in the right ischiocruralis (R: IC) muscle. This last action was associated to a transient increase of Tz (torque around body vertical axis) in the direction opposite to arm rotation. Both the APAs in R: IC and the Tz changes nearly doubled in size when arms were coupled isodirectionally (adduction of one arm and abduction on the other) while they vanished when both arms were simultaneously adducted (antidirectional coupling). Conformably, during rhythmic arm oscillations APAs and Tz were cyclically modulated when movements were isodirectional, the modulation amplitude being strongly enhanced by increasing the movement frequency. When oscillations were antidirectional neither APAs nor Tz changes were observed, even if frequency was incremented. The postural actions linked to unidirectional or cyclic movements of the hand were affected by either coupling or frequency in the same way as arm movements, albeit much smaller in size. In conclusion, during antidirectional movements APAs in prime movers are synergic with voluntary activation and no postural engagement is requested to leg muscles. Conversely, during isodirectional movements, APAs in prime movers conflict with the voluntary commands and a strong, frequency-dependent, postural effort is required to leg muscles. How these factors may co-operate in determining the preference for antidirectional coupling is discussed.

  4. Ca2+ movement in smooth muscle cells studied with one- and two-dimensional diffusion models.

    PubMed

    Kargacin, G; Fay, F S

    1991-11-01

    Although many of the processes involved in the regulation of Ca2+ in smooth muscle have been studied separately, it is still not well known how they are integrated into an overall regulatory system. To examine this question and to study the time course and spatial distribution of Ca2+ in cells after activation, one- and two-dimensional diffusion models of the cell that included the major processes thought to be involved in Ca regulation were developed. The models included terms describing Ca influx, buffering, plasma membrane extrusion, and release and reuptake by the sarcoplasmic reticulum. When possible these processes were described with known parameters. Simulations with the models indicated that the sarcoplasmic reticulum Ca pump is probably primarily responsible for the removal of cytoplasmic Ca2+ after cell activation. The plasma membrane Ca-ATPase and Na/Ca exchange appeared more likely to be involved in the long term regulation of Ca2+. Pumping processes in general had little influence on the rate of rise of Ca transients. The models also showed that spatial inhomogeneities in Ca2+ probably occur in cells during the spread of the Ca signal following activation and during the subsequent return of Ca2+ to its resting level.

  5. Acetylcholine receptor clustering and nuclear movement in muscle fibers in culture

    PubMed Central

    1987-01-01

    We have studied the formation of acetylcholine receptor (AChR) clusters and the behavior of myonuclei in rat and chick skeletal muscle cells grown in cell culture. These cells were treated with a factor derived from Torpedo electric extracellular matrix, which causes a large increase in their number of AChR clusters. We found that these clusters were located preferentially in membrane regions above myonuclei. This cluster-nucleus colocalization is explained by our finding that most of the nuclei near clusters remain relatively stationary, while most of those away from clusters are able to translocate throughout the myotube. In some cases, clusters clearly formed first, then nuclei migrated underneath and became immobilized. If clustered AChRs later dispersed, their associated nuclei resumed moving. These results suggest that AChR clustering initiates an extensive cytoskeletal rearrangement that causes the subcluster localization of organelles, potentially providing a stable source of newly synthesized AChRs for insertion into the cluster. PMID:3793762

  6. Adaptation of lower limb movement patterns when maintaining performance in the presence of muscle fatigue.

    PubMed

    Mudie, Kurt L; Gupta, Amitabh; Green, Simon; Clothier, Peter J

    2016-08-01

    Adaptations in lower limb movement patterns were examined when performance was maintained during a fatiguing repetitive loading task. Forty recreationally active male and female participants performed single-leg hopping to volitional exhaustion at 2.2Hz to a submaximal height. Spatio-temporal characteristics, mechanical characteristics and variability of the knee-ankle and hip-knee joint couplings were determined at 20% increments during the duration of the hopping task. Variability of the knee-ankle and hip-knee couplings in the flexion/extension axis significantly increased during the loading and propulsion phases during the hopping task (p<0.05). Performance (vertical stiffness, hopping frequency and height) did not change significantly during the task (p>0.05), however foot contact time increased progressively during this task (p<0.05) and maximum hop height significantly decreased after the task (p<0.05). The observed increase in variability between adjoining lower limb segments demonstrated the ability of the neuromotor system to adapt and maintain performance even with the onset of fatigue. This finding highlights that during the performance of a rapid and repetitive loading activity, performance can be preserved when there is variability in the neuromotor system.

  7. On Becoming an Involuntary Member in the Antepartum Unit.

    PubMed

    Peterson, Brittany L

    2016-08-01

    In this essay, I articulate the ways in which my scholarship and personal life collided when I became an involuntary member in the antepartum unit of a major university hospital. I draw on research examples taken from my dissertation work in prison and my time in the hospital to illustrate the interconnectedness of these involuntary experiences. After I share these stories, I offer a brief interlude to reflect on the meaningfulness of approaching membership from a continuum-based perspective and the relative implications for health communication scholars, before ending with an articulation how this experience brought me to a more crystallized view of involuntary membership.

  8. Spinal Motion and Muscle Activity during Active Trunk Movements – Comparing Sheep and Humans Adopting Upright and Quadrupedal Postures

    PubMed Central

    Valentin, Stephanie; Licka, Theresia F.

    2016-01-01

    Sheep are used as models for the human spine, yet comparative in vivo data necessary for validation is limited. The purpose of this study was therefore to compare spinal motion and trunk muscle activity during active trunk movements in sheep and humans. Three-dimensional kinematic data as well as surface electromyography (sEMG) of spinal flexion and extension was compared in twenty-four humans in upright (UR) and 4-point kneeling (KN) postures and in 17 Austrian mountain sheep. Kinematic markers were attached over the sacrum, posterior iliac spines, and spinous and transverse processes of T5, T8, T11, L2 and L5 in humans and over the sacrum, tuber sacrale, T5, T8, T12, L3 and L7 in sheep. The activity of erector spinae (ES), rectus abdominis (RA), obliquus externus (OE), and obliquus internus (OI) were collected. Maximum sEMG (MOE) was identified for each muscle and trial, and reported as a percentage (MOE%) of the overall maximally observed sEMG from all trials. Spinal range of motion was significantly smaller in sheep compared to humans (UR / KN) during flexion (sheep: 6–11°; humans 12–34°) and extension (sheep: 4°; humans: 11–17°). During extension, MOE% of ES was greater in sheep (median: 77.37%) than UR humans (24.89%), and MOE% of OE and OI was greater in sheep (OE 76.20%; OI 67.31%) than KN humans (OE 21.45%; OI 19.34%), while MOE% of RA was lower in sheep (21.71%) than UR humans (82.69%). During flexion, MOE% of RA was greater in sheep (83.09%) than humans (KN 47.42%; UR 41.38%), and MOE% of ES in sheep (45.73%) was greater than KN humans (14.45%), but smaller than UR humans (72.36%). The differences in human and sheep spinal motion and muscle activity suggest that caution is warranted when ovine data are used to infer human spine biomechanics. PMID:26741136

  9. Muscle Recruitment and Coordination following Constraint-Induced Movement Therapy with Electrical Stimulation on Children with Hemiplegic Cerebral Palsy: A Randomized Controlled Trial

    PubMed Central

    Xu, Kaishou; He, Lu; Mai, Jianning; Yan, Xiaohua; Chen, Ying

    2015-01-01

    Objective To investigate changes of muscle recruitment and coordination following constraint-induced movement therapy, constraint-induced movement therapy plus electrical stimulation, and traditional occupational therapy in treating hand dysfunction. Methods In a randomized, single-blind, controlled trial, children with hemiplegic cerebral palsy were randomly assigned to receive constraint-induced movement therapy (n = 22), constraint-induced movement therapy plus electrical stimulation (n = 23), or traditional occupational therapy (n = 23). Three groups received a 2-week hospital-based intervention and a 6-month home-based exercise program following hospital-based intervention. Constraint-induced movement therapy involved intensive functional training of the involved hand during which the uninvolved hand was constrained. Electrical stimulation was applied on wrist extensors of the involved hand. Traditional occupational therapy involved functional unimanual and bimanual training. All children underwent clinical assessments and surface electromyography (EMG) at baseline, 2 weeks, 3 and 6 months after treatment. Surface myoelectric signals were integrated EMG, root mean square and cocontraction ratio. Clinical measures were grip strength and upper extremity functional test. Results Constraint-induced movement therapy plus electrical stimulation group showed both a greater rate of improvement in integrated EMG of the involved wrist extensors and cocontraction ratio compared to the other two groups at 3 and 6 months, as well as improving in root mean square of the involved wrist extensors than traditional occupational therapy group (p<0.05). Positive correlations were found between both upper extremity functional test scores and integrated EMG of the involved wrist as well as grip strength and integrated EMG of the involved wrist extensors (p<0.05). Conclusions Constraint-induced movement therapy plus electrical stimulation is likely to produce the best outcome in

  10. Changes of calf muscle-tendon biomechanical properties induced by passive-stretching and active-movement training in children with cerebral palsy

    PubMed Central

    Zhao, Heng; Wu, Yi-Ning; Hwang, Miriam; Ren, Yupeng; Gao, Fan; Gaebler-Spira, Deborah

    2011-01-01

    Biomechanical properties of calf muscles and Achilles tendon may be altered considerably in children with cerebral palsy (CP), contributing to childhood disability. It is unclear how muscle fascicles and tendon respond to rehabilitation and contribute to improvement of ankle-joint properties. Biomechanical properties of the calf muscle fascicles of both gastrocnemius medialis (GM) and soleus (SOL), including the fascicle length and pennation angle in seven children with CP, were evaluated using ultrasonography combined with biomechanical measurements before and after a 6-wk treatment of passive-stretching and active-movement training. The passive force contributions from the GM and SOL muscles were separated using flexed and extended knee positions, and fascicular stiffness was calculated based on the fascicular force-length relation. Biomechanical properties of the Achilles tendon, including resting length, cross-sectional area, and stiffness, were also evaluated. The 6-wk training induced elongation of muscle fascicles (SOL: 8%, P = 0.018; GM: 3%, P = 0.018), reduced pennation angle (SOL: 10%, P = 0.028; GM: 5%, P = 0.028), reduced fascicular stiffness (SOL: 17%, P = 0.128; GM: 21%, P = 0.018), decreased tendon length (6%, P = 0.018), increased Achilles tendon stiffness (32%, P = 0.018), and increased Young's modulus (20%, P = 0.018). In vivo characterizations of calf muscles and Achilles tendon mechanical properties help us better understand treatment-induced changes of calf muscle-tendon and facilitate development of more effective treatments. PMID:21596920

  11. Changes of calf muscle-tendon biomechanical properties induced by passive-stretching and active-movement training in children with cerebral palsy.

    PubMed

    Zhao, Heng; Wu, Yi-Ning; Hwang, Miriam; Ren, Yupeng; Gao, Fan; Gaebler-Spira, Deborah; Zhang, Li-Qun

    2011-08-01

    Biomechanical properties of calf muscles and Achilles tendon may be altered considerably in children with cerebral palsy (CP), contributing to childhood disability. It is unclear how muscle fascicles and tendon respond to rehabilitation and contribute to improvement of ankle-joint properties. Biomechanical properties of the calf muscle fascicles of both gastrocnemius medialis (GM) and soleus (SOL), including the fascicle length and pennation angle in seven children with CP, were evaluated using ultrasonography combined with biomechanical measurements before and after a 6-wk treatment of passive-stretching and active-movement training. The passive force contributions from the GM and SOL muscles were separated using flexed and extended knee positions, and fascicular stiffness was calculated based on the fascicular force-length relation. Biomechanical properties of the Achilles tendon, including resting length, cross-sectional area, and stiffness, were also evaluated. The 6-wk training induced elongation of muscle fascicles (SOL: 8%, P = 0.018; GM: 3%, P = 0.018), reduced pennation angle (SOL: 10%, P = 0.028; GM: 5%, P = 0.028), reduced fascicular stiffness (SOL: 17%, P = 0.128; GM: 21%, P = 0.018), decreased tendon length (6%, P = 0.018), increased Achilles tendon stiffness (32%, P = 0.018), and increased Young's modulus (20%, P = 0.018). In vivo characterizations of calf muscles and Achilles tendon mechanical properties help us better understand treatment-induced changes of calf muscle-tendon and facilitate development of more effective treatments.

  12. Submental sEMG and hyoid movement during Mendelsohn maneuver, effortful swallow, and expiratory muscle strength training.

    PubMed

    Wheeler-Hegland, Karen M; Rosenbek, John C; Sapienza, Christine M

    2008-10-01

    This study investigated the concurrent biomechanical and electromyographic properties of 2 swallow-specific tasks (effortful swallow and Mendelsohn maneuver) and 1 swallow-nonspecific (expiratory muscle strength training [EMST]) swallow therapy task in order to examine the differential effects of each on hyoid motion and associated submental activation in healthy adults, with the overall goal of characterizing task-specific and overload properties of each task. Twenty-five healthy male and female adults (M = 25 years of age) participated in this prospective, experimental study with 1 participant group. Each participant completed all study tasks (including normal swallow, Mendelsohn maneuver swallow, effortful swallow, and EMST task) in random order during concurrent videofluoroscopy and surface electromyography recording. Results revealed significant differences in the trajectory of hyoid motion as measured by overall displacement and angle of elevation of the hyoid bone. As well, timing of hyoid movement and amplitude differences existed between tasks with regard to the activation of the submental musculature. Study results demonstrated differential effects of the 3 experimental tasks on the principles of task specificity and overload. These principles are important in the development of effective rehabilitative programs. Subsequent direction for future research is suggested.

  13. Changes of calf muscle-tendon properties due to stretching and active movement of children with cerebral palsy--a pilot study.

    PubMed

    Zhao, Heng; Wu, Yi-Ning; Liu, Jie; Ren, Yupeng; Gaebler-Spira, Deborah J; Zhang, Li-Qun

    2009-01-01

    A portable ankle rehabilitation robot with intelligent stretching and game-based active movement training was used to treat the spastic impaired ankle of children with cerebral palsy over six weeks. The subject's calf muscles and Achilles tendon properties were evaluated before and after treatment using ultrasonography and biomechanical measures. It was found that there were decreased Achilles tendon resting length (2.5%), increased cross-sectional area (5.5%), increased stiffness (22.9%), increased Young's modulus (13.8%), decreased soleus muscle fascicular stiffness (53.7%), and decreased medial gastrocnemius fascicular stiffness (46.1%).

  14. Physiologic facial muscle uptake on 18F-FDG PET/CT by chewing-like habitual movement in patient with Sjögren syndrome.

    PubMed

    Lee, Dong Hyun; Yoon, Joon-Kee; Yoon, Seok-Ho; Lee, Su Jin; An, Young-Sil

    2015-03-01

    An 84-year-old female patient with known Sjögren syndrome underwent 18F-FDG PET/CT to detect recurrence of uterine cervix cancer. Sjögren syndrome is autoimmune disease that typically produces symptoms of dry mouth and eyes. We report a case of physiologic 18F-FDG uptake on facial muscles by chewing-like habitual movement, which was confused with salivary retention at first. The physiologic FDG uptake in oral cavity and facial muscles has to be reviewed carefully not to be confused with abnormal uptake.

  15. Involuntary (spontaneous) mental time travel into the past and future.

    PubMed

    Berntsen, Dorthe; Jacobsen, Anne Staerk

    2008-12-01

    Mental time travel (MTT) is the ability to mentally project oneself backward in time to relive past experiences and forward in time to pre-live possible future experiences. Previous work has focused on MTT in its voluntary (controlled) form. Here, we introduce the notion of involuntary (spontaneous) MTT. We examined involuntary versus voluntary and past versus future MTT in a diary study. We found that involuntary future event representations-defined as representations of possible personal future events that come to mind with no preceding search attempts-were as common as involuntary autobiographical memories and similar to them regarding cuing and subjective qualities. Future MTT involved more positive and idyllic representations than past MTT. MTT into the distant future/past involved more representations of cultural life script events than MTT into the immediate past/future. The findings are discussed in relation to cultural learning and MTT considered as a higher mental process.

  16. Active suppression after involuntary capture of attention.

    PubMed

    Sawaki, Risa; Luck, Steven J

    2013-04-01

    After attention has been involuntarily captured by a distractor, how is it reoriented toward a target? One possibility is that attention to the distractor passively fades over time, allowing the target to become attended. Another possibility is that the captured location is actively suppressed so that attention can be directed toward the target location. The present study investigated this issue with event-related potentials (ERPs), focusing on the N2pc component (a neural measure of attentional deployment) and the Pd component (a neural measure of attentional suppression). Observers identified a color-defined target in a search array, which was preceded by a task-irrelevant cue array. When the cue array contained an item that matched the target color, this item captured attention (as measured both behaviorally and with the N2pc component). This capture of attention was followed by active suppression (indexed by the Pd component), and this was then followed by a reorienting of attention toward the target in the search array (indexed by the N2pc component). These findings indicate that the involuntary capture of attention by a distractor is followed by an active suppression process that presumably facilitates the subsequent voluntary orienting of attention to the target.

  17. Ultrasound of oral and masticatory muscles: Why every neuromuscular swallow team should have an ultrasound machine.

    PubMed

    Van Den Engel-Hoek, Lenie; Lagarde, Marloes; Van Alfen, Nens

    2017-03-01

    Patients with neuromuscular disorders often present with swallowing difficulties due to oral phase problems and pharyngeal residue after swallow. It is important to assess the underlying pathology and cause of the swallowing disturbance in this patient group, such as dystrophic changes in oral and masticatory muscles. This allows for more patient-tailored recommendations, for example optimal compensation strategies to maintain function for longer. Ultrasound can show structural changes caused by dystrophy or denervation of muscles, detect involuntary movements such as fasciculations, and provide dynamic video images of tongue motion during swallowing attempts. This article, based on the authors' extensive experience with ultrasound in neuromuscular disease, explains the concepts of oral muscle ultrasound and its proven value in assessing neuromuscular mastication and swallowing problems. As a patient-friendly and portable technique, we advocate its use as a standard tool for analyzing neuromuscular dysphagia. Clin. Anat. 30:183-193, 2017. © 2017 Wiley Periodicals, Inc.

  18. Involuntary, forced and voluntary exercises are equally capable of inducing hippocampal plasticity and the recovery of cognitive function after stroke.

    PubMed

    Lin, Yangyang; Dong, Juntao; Yan, Tiebin; He, Xiaokuo; Zheng, Xiuyuan; Liang, Huiying; Sui, Minghong

    2015-10-01

    Forced and voluntary exercises are known to improve cognition and induce neuroprotection after stroke, however, any effects of involuntary movement induced by functional electrical stimulation (FES) are unclear. The effects of involuntary exercise induced by FES, forced and voluntary exercise on the recovery of cognitive function in vascular dementia and the regional repair of ischaemic lesions were investigated using a rat model. Wistar rats were randomly assigned to a sham group, a vascular dementia control group (VD), an involuntary exercise group (I-Ex), a forced exercise group (F-Ex) or a voluntary exercise group (V-Ex). An object recognition test (ORT) and an object location test (OLT) were used to evaluate the recovery of cognitive function. Levels of synapsin I (SYN), synaptophysin (SYP), postsynaptic density 95 (PSD-95), microtubule-associated protein 2 (MAP-2) and Tau in the hippocampus were evaluated using western blotting and immunohistochemistry. Nissl staining was applied to visualise the loss of viable neurons from the hippocampus. Involuntary exercise and voluntary exercise both improved cognition in terms of ORT and OLT results. Forced exercise only improved ORT results. The levels of SYN, PSD-95, MAP-2 and Tau in the hippocampus were enhanced by all three patterns of exercise training. Moreover, all three patterns reduced losses of dendrons and neurons in the hippocampal CA1 and CA2 zones, but without significant differences among the three exercise regimens. Involuntary exercise induced by FES has beneficial effects on cognitive function after vascular dementia comparable to those of forced and voluntary exercise.

  19. Influence of chronic low back pain and fear of movement on the activation of the transversely oriented abdominal muscles during forward bending.

    PubMed

    Massé-Alarie, Hugo; Beaulieu, Louis-David; Preuss, Richard; Schneider, Cyril

    2016-04-01

    Chronic low back pain (CLBP) and fear of movement (kinesiophobia) are associated with an overactivation of paravertebral muscles during forward bending. This impairs spine motor control and contributes to pain perpetuation. However, the abdominal muscles activation is engaged too in spine stabilization but its modulation with kinesiophobia remains unknown. Our study tested whether CLBP and kinesiophobia affected the activation pattern of abdominal muscles during trunk flexion/extension. Surface electromyographical recordings of the internal oblique/transversus abdominis (IO/TrA) and external oblique (EO) muscles were analyzed in 12 people with CLBP and 13 pain-free subjects during low-velocity forward bending back and forth from erected posture. Tampa Scale of Kinesiophobia was also administrated. IO/TrA activation, but not EO, was modulated across the phases of movement in both groups, i.e. maximal at onset of flexion and end of extension, and minimal at full flexion. In CLBP group only, IO/TrA activation was increased near to full trunk flexion and in correlation with kinesiophobia. The phase-dependence of IO/TrA activation during trunk flexion/extension in standing may have a role in spine motor control. The influence of kinesiophobia in CLBP should be further investigated as an important target in CLBP management. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Appraisals Generate Specific Configurations of Facial Muscle Movements in a Gambling Task: Evidence for the Component Process Model of Emotion

    PubMed Central

    Gentsch, Kornelia; Grandjean, Didier; Scherer, Klaus R.

    2015-01-01

    Scherer’s Component Process Model provides a theoretical framework for research on the production mechanism of emotion and facial emotional expression. The model predicts that appraisal results drive facial expressions, which unfold sequentially and cumulatively over time. In two experiments, we examined facial muscle activity changes (via facial electromyography recordings over the corrugator, cheek, and frontalis regions) in response to events in a gambling task. These events were experimentally manipulated feedback stimuli which presented simultaneous information directly affecting goal conduciveness (gambling outcome: win, loss, or break-even) and power appraisals (Experiment 1 and 2), as well as control appraisal (Experiment 2). We repeatedly found main effects of goal conduciveness (starting ~600 ms), and power appraisals (starting ~800 ms after feedback onset). Control appraisal main effects were inconclusive. Interaction effects of goal conduciveness and power appraisals were obtained in both experiments (Experiment 1: over the corrugator and cheek regions; Experiment 2: over the frontalis region) suggesting amplified goal conduciveness effects when power was high in contrast to invariant goal conduciveness effects when power was low. Also an interaction of goal conduciveness and control appraisals was found over the cheek region, showing differential goal conduciveness effects when control was high and invariant effects when control was low. These interaction effects suggest that the appraisal of having sufficient control or power affects facial responses towards gambling outcomes. The result pattern suggests that corrugator and frontalis regions are primarily related to cognitive operations that process motivational pertinence, whereas the cheek region would be more influenced by coping implications. Our results provide first evidence demonstrating that cognitive-evaluative mechanisms related to goal conduciveness, control, and power appraisals affect

  1. Appraisals Generate Specific Configurations of Facial Muscle Movements in a Gambling Task: Evidence for the Component Process Model of Emotion.

    PubMed

    Gentsch, Kornelia; Grandjean, Didier; Scherer, Klaus R

    2015-01-01

    Scherer's Component Process Model provides a theoretical framework for research on the production mechanism of emotion and facial emotional expression. The model predicts that appraisal results drive facial expressions, which unfold sequentially and cumulatively over time. In two experiments, we examined facial muscle activity changes (via facial electromyography recordings over the corrugator, cheek, and frontalis regions) in response to events in a gambling task. These events were experimentally manipulated feedback stimuli which presented simultaneous information directly affecting goal conduciveness (gambling outcome: win, loss, or break-even) and power appraisals (Experiment 1 and 2), as well as control appraisal (Experiment 2). We repeatedly found main effects of goal conduciveness (starting ~600 ms), and power appraisals (starting ~800 ms after feedback onset). Control appraisal main effects were inconclusive. Interaction effects of goal conduciveness and power appraisals were obtained in both experiments (Experiment 1: over the corrugator and cheek regions; Experiment 2: over the frontalis region) suggesting amplified goal conduciveness effects when power was high in contrast to invariant goal conduciveness effects when power was low. Also an interaction of goal conduciveness and control appraisals was found over the cheek region, showing differential goal conduciveness effects when control was high and invariant effects when control was low. These interaction effects suggest that the appraisal of having sufficient control or power affects facial responses towards gambling outcomes. The result pattern suggests that corrugator and frontalis regions are primarily related to cognitive operations that process motivational pertinence, whereas the cheek region would be more influenced by coping implications. Our results provide first evidence demonstrating that cognitive-evaluative mechanisms related to goal conduciveness, control, and power appraisals affect

  2. Muscle Repositioning: a new verifiable approach to neuro-myofascial release?

    PubMed

    Bertolucci, Luiz Fernando

    2008-07-01

    The clinical observation of involuntary motor activity during application of a particular style of myofascial release (Muscle Repositioning-MR) has led to the hypothesis that this technique might evoke neurological reactions. Preliminary EMG recordings presented here show involuntary tonic cervical erector action during MR. Involuntary eye movements were also observed. This article presents these experimental data, along with clinical observations during the application of MR in the treatment of musculoskeletal conditions. The author hypothesizes that MR might constitute a novel manual technique: it produces unique palpatory sensations for the practitioner (e.g., a sense of firmness to the touch and the integration of bodily segments into a single block) that correspond to unique sensory experiences for the client. The article raises the possibility that MR's specific sensory input might activate the central nervous system, thus eliciting neural reactions. These reactions, in turn, might be related to the technique's efficacy. As the EMG objectively measures reactions contemporaneous with subjective palpatory phenomena, MR potentially brings the objective and subjective into congruence. EMG monitoring of touch could serve as an objective criterion in the development of treatment protocols, as well as a feedback tool for teaching. Greater objectivity, precision and reproducibility are all possible outcomes of such an approach. The author believes that MR can be used in various therapeutic settings--either as the principal approach, or as an adjunct to a variety of other approaches.

  3. A fuzzy-genetic model for estimating forces from electromyographical activity of antagonistic muscles due to planar lower arm movements: the effect of nonlinear muscle properties.

    PubMed

    Nowshiravan Rahatabad, Fereidoun; Jafari, Amir Homayoun; Fallah, Ali; Razjouyan, Javad

    2012-01-01

    The aim of this paper is to create a model for mapping the surface electromyogram (EMG) signals to the force that generated by human arm muscles. Because the parameters of each person's muscle are individual, the model of the muscle must have two characteristics: (1) The model must be adjustable for each subject. (2) The relationship between the input and output of model must be affected by the force-length and the force-velocity behaviors are proven through Hill's experiments. Hill's model is a kinematic mechanistic model with three elements, i.e. one contractile component and two nonlinear spring elements. In this research, fuzzy systems are applied to improve the muscle model. The advantages of using fuzzy system are as follows: they are robust to noise, they prove an adjustable nonlinear mapping, and are able to model the uncertainties of the muscle. Three fuzzy coefficients have been added to the relationships of force-length (active and passive) and force-velocity existing in Hill's model. Then, a genetic algorithm (GA) has been used as a biological search method that can adjust the parameters of the model in order to achieve the optimal possible fit. Finally, the accuracy of the fuzzy genetic implementation Hill-based muscle model (FGIHM) is invested as following: the FGIHM results have 12.4% RMS error (in worse case) in comparison to the experimental data recorded from three healthy male subjects. Moreover, the FGIHM active force-length relationship which is the key characteristics of muscles has been compared to virtual muscle (VM) and Zajac muscle model. The sensitivity of the FGIHM has been evaluated by adding a white noise with zero mean to the input and FGIHM has proved to have lower sensitivity to input noise than the traditional Hill's muscle model. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Physiology of Psychogenic Movement Disorders

    PubMed Central

    Hallett, Mark

    2010-01-01

    Psychogenic movement disorders (PMDs) are common, but their physiology is largely unknown. In most situations, the movement is involuntary, but in a minority, when the disorder is malingering or factitious, the patient is lying and the movement is voluntary. Physiologically, we cannot tell the difference between voluntary and involuntary. The Bereitschaftspotential (BP) is indicative of certain brain mechanisms for generating movement, and is seen with ordinarily voluntary movements, but by itself does not indicate that a movement is voluntary. There are good clinical neurophysiological methods available to determine whether myoclonus or tremor is a PMD. For example, psychogenic myoclonus generally has a BP, and psychogenic stimulus-sensitive myoclonus has a variable latency with times similar to normal reaction times. Psychogenic tremor will have variable frequency over time, be synchronous in the two arms, and might well be entrained with voluntary rhythmic movements. These facts suggest that PMDs share voluntary mechanisms for movement production. There are no definitive tests to differentiate psychogenic dystonia from organic dystonia, although one has been recently reported. Similar physiological abnormalities are seen in both groups. The question arises as to how a movement can be produced with voluntary mechanisms, but not be considered voluntary. PMID:20493708

  5. Physiology of psychogenic movement disorders.

    PubMed

    Hallett, Mark

    2010-08-01

    Psychogenic movement disorders (PMDs) are common, but their physiology is largely unknown. In most situations, the movement is involuntary, but in a minority, when the disorder is malingering or factitious, the patient is lying and the movement is voluntary. Physiologically, we cannot tell the difference between voluntary and involuntary. The Bereitschaftspotential (BP) is indicative of certain brain mechanisms for generating movement, and is seen with ordinarily voluntary movements, but by itself does not indicate that a movement is voluntary. There are good clinical neurophysiological methods available to determine whether myoclonus or tremor is a PMD. For example, psychogenic myoclonus generally has a BP, and psychogenic stimulus-sensitive myoclonus has a variable latency with times similar to normal reaction times. Psychogenic tremor will have variable frequency over time, be synchronous in the two arms, and might well be entrained with voluntary rhythmic movements. These facts suggest that PMDs share voluntary mechanisms for movement production. There are no definitive tests to differentiate psychogenic dystonia from organic dystonia, although one has been recently reported. Similar physiological abnormalities are seen in both groups. The question arises as to how a movement can be produced with voluntary mechanisms, but not be considered voluntary.

  6. Sustained overexpression of IGF-1 prevents age-dependent decrease in charge movement and intracellular Ca(2+) in mouse skeletal muscle.

    PubMed

    Wang, Zhong-Min; Messi, María Laura; Delbono, Osvaldo

    2002-03-01

    In this work we tested the hypothesis that transgenic sustained overexpression of IGF-1 prevents age-dependent decreases in charge movement and intracellular Ca(2+) in skeletal muscle fibers. To this end, short flexor digitorum brevis (FDB) muscle fibers from 5-7- and 21-24-month-old FVB (wild-type) and S1S2 (IGF-1 transgenic) mice were studied. Fibers were voltage-clamped in the whole-cell configuration of the patch-clamp technique according to described procedures (Wang, Z. M., M. L. Messi, and O. Delbono. 1999. Biophys. J. 77:2709-2716). Charge movement and intracellular Ca(2+) concentration were recorded simultaneously. The maximum charge movement (Q(max)) recorded in young wild-type and transgenic mice was (mean +/- SEM, in nC microF(-1)): 52 +/- 2.1 (n = 46) and 54 +/- 1.9 (n = 38) (non-significant, ns), respectively, whereas in old wild-type and old transgenic mice the values were 36 +/- 2.1 (n = 32) and 49 +/- 2.3 (n = 35), respectively (p < 0.01). The peak intracellular calcium [Ca(2+)](i) recorded in young wild-type and transgenic mice was (in muM): 14.5 +/- 0.9 and 16 +/- 2.1 (ns), whereas in old wild-type and transgenic mice the values were 9.9 +/- 0.1 and 14 +/- 1.1 (p < 0.01), respectively. No significant changes in the voltage distribution or steepness of the Q-V or [Ca(2+)]-V relationship were found. These data support the concept that overexpression of IGF-1 in skeletal muscle prevents age-dependent reduction in charge movement and peak [Ca(2+)](i).

  7. Short-term involuntary examination of older adults in Florida.

    PubMed

    Christy, Annette; Bond, Jennifer; Young, M Scott

    2007-01-01

    The elder population continues to grow rapidly in many countries. Florida's elder population is growing faster than most states', with over one-quarter of the Florida population projected to be aged 65 and over by 2025. Involuntary examination (i.e. emergency commitment) under a state's civil commitment law is one means by which older adults experience assessment for acute mental health care. In Florida, the civil commitment law permits the involuntary examination of an individual for up to 72 hours to determine whether the person meets standards for involuntary treatment. From calendar year 2001 through 2005, there were 531,091 involuntary examinations in Florida for 301,886 people of all ages. Thirteen percent were 60 years and older at the time of their examination. The purpose of this paper is to describe the characteristics of older adults subject to involuntary examination and the nature of their examinations. While these data permit a number of inferences, there is an expansive area of research and policy analysis that remains untapped and would permit better understanding of how older adults experience such examinations. These research and policy issues will also be discussed.

  8. 1988 Volvo award in biomechanics. The triaxial coupling of torque generation of trunk muscles during isometric exertions and the effect of fatiguing isoinertial movements on the motor output and movement patterns.

    PubMed

    Parnianpour, M; Nordin, M; Kahanovitz, N; Frankel, V

    1988-09-01

    Previous studies have shown that reduction of precise motor control accompanies local muscular fatigue. The effects of isodynamic fatiguing of flexion and extension trunk movements on the movement patterns and the motor output of the trunk were investigated. Twenty male subjects with no history of low-back pain for the past 6 months volunteered for the study. A triaxial dynamometer was used that simultaneously provided measurement of torque, angular position and velocity of each axis. Resistances were set independently for each axis by an interfaced computer. The subjects performed trunk flexion and extension movement against a sagittal plane resistance equal to 70% of their maximum isometric extension strength in the upright position. The minimum resistances in the coronal and transverse planes were set up at 7 Newton meters. The subjects were asked to perform trunk movement as quickly and as accurately as possible while exerting the maximum efforts until exhaustion. Analysis of variance, the MANOVA procedure with a repeated measure design, was performed among the selected parameters of the first, middle and last three repetition cycles. The selected parameters are the trunk motor output and movement patterns; the total angular excursion, range of motion, maximum and average torque and angular velocity of the trunk. All the selected parameters were significantly reduced in the sagittal plane. Subjects displayed significantly less motor control and greater range of motion in the coronal and transverse planes in performing the primary task of flexion and extension. The reduction in the functional capacity of the primary muscles performing the required task is compensated by secondary muscle groups and the spinal structure is loaded in a more injury prone pattern, as identified by finite element models. In addition it is suggested that the fatigued muscles would be less able to compensate any perturbation in the load or position of the trunk. The repetitive loading

  9. Comparison of myoplasmic calcium movements during excitation–contraction coupling in frog twitch and mouse fast-twitch muscle fibers

    PubMed Central

    Hollingworth, Stephen

    2013-01-01

    Single twitch fibers from frog leg muscles were isolated by dissection and micro-injected with furaptra, a rapidly responding fluorescent Ca2+ indicator. Indicator resting fluorescence (FR) and the change evoked by an action potential (ΔF) were measured at long sarcomere length (16°C); ΔF/FR was scaled to units of ΔfCaD, the change in fraction of the indicator in the Ca2+-bound form. ΔfCaD was simulated with a multicompartment model of the underlying myoplasmic Ca2+ movements, and the results were compared with previous measurements and analyses in mouse fast-twitch fibers. In frog fibers, sarcoplasmic reticulum (SR) Ca2+ release evoked by an action potential appears to be the sum of two components. The time course of the first component is similar to that of the entire Ca2+ release waveform in mouse fibers, whereas that of the second component is severalfold slower; the fractional release amounts are ∼0.8 (first component) and ∼0.2 (second component). Similar results were obtained in frog simulations with a modified model that permitted competition between Mg2+ and Ca2+ for occupancy of the regulatory sites on troponin. An anatomical basis for two release components in frog fibers is the presence of both junctional and parajunctional SR Ca2+ release channels (ryanodine receptors [RyRs]), whereas mouse fibers (usually) have only junctional RyRs. Also, frog fibers have two RyR isoforms, RyRα and RyRβ, whereas the mouse fibers (usually) have only one, RyR1. Our simulations suggest that the second release component in frog fibers functions to supply extra Ca2+ to activate troponin, which, in mouse fibers, is not needed because of the more favorable location of their triadic junctions (near the middle of the thin filament). We speculate that, in general, parajunctional RyRs permit increased myofilament activation in fibers whose triadic junctions are located at the z-line. PMID:23630340

  10. Comparison of myoplasmic calcium movements during excitation-contraction coupling in frog twitch and mouse fast-twitch muscle fibers.

    PubMed

    Hollingworth, Stephen; Baylor, Stephen M

    2013-05-01

    Single twitch fibers from frog leg muscles were isolated by dissection and micro-injected with furaptra, a rapidly responding fluorescent Ca(2+) indicator. Indicator resting fluorescence (FR) and the change evoked by an action potential (ΔF) were measured at long sarcomere length (16°C); ΔF/FR was scaled to units of ΔfCaD, the change in fraction of the indicator in the Ca(2+)-bound form. ΔfCaD was simulated with a multicompartment model of the underlying myoplasmic Ca(2+) movements, and the results were compared with previous measurements and analyses in mouse fast-twitch fibers. In frog fibers, sarcoplasmic reticulum (SR) Ca(2+) release evoked by an action potential appears to be the sum of two components. The time course of the first component is similar to that of the entire Ca(2+) release waveform in mouse fibers, whereas that of the second component is severalfold slower; the fractional release amounts are ~0.8 (first component) and ~0.2 (second component). Similar results were obtained in frog simulations with a modified model that permitted competition between Mg(2+) and Ca(2+) for occupancy of the regulatory sites on troponin. An anatomical basis for two release components in frog fibers is the presence of both junctional and parajunctional SR Ca(2+) release channels (ryanodine receptors [RyRs]), whereas mouse fibers (usually) have only junctional RyRs. Also, frog fibers have two RyR isoforms, RyRα and RyRβ, whereas the mouse fibers (usually) have only one, RyR1. Our simulations suggest that the second release component in frog fibers functions to supply extra Ca(2+) to activate troponin, which, in mouse fibers, is not needed because of the more favorable location of their triadic junctions (near the middle of the thin filament). We speculate that, in general, parajunctional RyRs permit increased myofilament activation in fibers whose triadic junctions are located at the z-line.

  11. Voltage-sensor movements describe slow inactivation of voltage-gated sodium channels I: Wild-type skeletal muscle NaV1.4

    PubMed Central

    Silva, Jonathan R.

    2013-01-01

    The number of voltage-gated sodium (NaV) channels available to generate action potentials in muscles and nerves is adjusted over seconds to minutes by prior electrical activity, a process called slow inactivation (SI). The basis for SI is uncertain. NaV channels have four domains (DI–DIV), each with a voltage sensor that moves in response to depolarizing stimulation over milliseconds to activate the channels. Here, SI of the skeletal muscle channel NaV1.4 is induced by repetitive stimulation and is studied by recording of sodium currents, gating currents, and changes in the fluorescence of probes on each voltage sensor to assess their movements. The magnitude, voltage dependence, and time course of the onset and recovery of SI are observed to correlate with voltage-sensor movements 10,000-fold slower than those associated with activation. The behavior of each voltage sensor is unique. Development of SI over 1–160 s correlates best with slow immobilization of the sensors in DI and DII; DIII tracks the onset of SI with less fidelity. Showing linkage to the sodium conduction pathway, pore block by tetrodotoxin affects both SI and immobilization of all the sensors, with DI and DII significantly suppressed. Recovery from SI correlates best with slow restoration of mobility of the sensor in DIII. The findings suggest that voltage-sensor movements determine SI and thereby mediate NaV channel availability. PMID:23401571

  12. Effect of co-activation of tongue protrudor and retractor muscles on tongue movements and pharyngeal airflow mechanics in the rat

    PubMed Central

    Fuller, D D; Williams, J S; Janssen, P L; Fregosi, R F

    1999-01-01

    The purpose of these experiments was to examine the mechanisms by which either co-activation or independent activation of tongue protrudor and retractor muscles influence upper airway flow mechanics. We studied the influence of selective hypoglossal (XIIth) nerve stimulation on tongue movements and flow mechanics in anaesthetized rats that were prepared with an isolated upper airway. In this preparation, both nasal and oral flow pathways are available. Inspiratory flow limitation was achieved by rapidly lowering hypopharyngeal pressure (Php) with a vacuum pump, and the maximal rate of flow (VI,max) and the nasopharyngeal pressure associated with flow limitation (Pcrit) were measured. These experimental trials were repeated while nerve branches innervating tongue protrudor (genioglossus; medial XIIth nerve branch) and retractor (hyoglossus and styloglossus; lateral XIIth nerve branch) muscles were stimulated either simultaneously or independently at frequencies ranging from 20-100 Hz. Co-activating the protrudor and retractor muscles produced tongue retraction, whereas independently activating the genioglossus resulted in tongue protrusion. Co-activation of tongue protrudor and retractor muscles increased VI,max (peak increase 44 %, P < 0.05), made Pcrit more negative (peak decrease of 44 %, P < 0.05), and did not change upstream nasopharyngeal resistance (Rn). Independent protrudor muscle stimulation increased VI,max (peak increase 61 %, P < 0.05), did not change Pcrit, and decreased Rn (peak decrease of 41 %, P < 0.05). Independent retractor muscle stimulation did not significantly alter flow mechanics. Changes in Pcrit and VI,max at all stimulation frequencies were significantly correlated during co-activation of protrudor and retractor muscles (r2= 0.63, P < 0.05), but not during independent protrudor muscle stimulation (r2= 0.09). These findings indicate that either co-activation of protrudor and retractor muscles or independent activation of protrudor muscles

  13. Movement disorders in cerebrovascular disease.

    PubMed

    Mehanna, Raja; Jankovic, Joseph

    2013-06-01

    Movement disorders can occur as primary (idiopathic) or genetic disease, as a manifestation of an underlying neurodegenerative disorder, or secondary to a wide range of neurological or systemic diseases. Cerebrovascular diseases represent up to 22% of secondary movement disorders, and involuntary movements develop after 1-4% of strokes. Post-stroke movement disorders can manifest in parkinsonism or a wide range of hyperkinetic movement disorders including chorea, ballism, athetosis, dystonia, tremor, myoclonus, stereotypies, and akathisia. Some of these disorders occur immediately after acute stroke, whereas others can develop later, and yet others represent delayed-onset progressive movement disorders. These movement disorders have been encountered in patients with ischaemic and haemorrhagic strokes, subarachnoid haemorrhage, cerebrovascular malformations, and dural arteriovenous fistula affecting the basal ganglia, their connections, or both.

  14. Unintended hand movements after abrupt cessation of variable and constant opposing forces.

    PubMed

    Rapp, K; Heuer, H

    2013-04-16

    Humans are highly efficient in moving in a world of variable resistive forces which result, e.g., from different masses of objects or different directions of movements relative to gravity. However, the underlying mechanisms are challenged when an opposing force is suddenly removed. The resulting involuntary movements are known as accident risks in everyday life. We studied their characteristics upon abrupt cessations of opposing forces of 1, 2, and 4N which were presented in a series of variable or constant forces. The characteristics of the involuntary hand movements are largely determined by the mechanical impedance of the limb. The involuntary movements are oscillatory in nature, and their amplitude increases with stronger opposing force. Limb impedance is modulated both in a reactive and in an anticipatory manner. The reactive modulation occurs during each involuntary movement as a consequence of the neural responses elicited by the rapid limb acceleration consequent upon the cessation of the opposing force. Anticipatory modulation of limb impedance may serve to produce similar involuntary movements in spite of different opposing forces. The modulation is thus stronger with variable forces, where differences between resulting involuntary movements can be experienced more easily, than with constant forces.

  15. Involuntary hospitalization of the mentally ill as a moral issue.

    PubMed

    Chodoff, P

    1984-03-01

    Conflict exists between medical model and civil liberties approaches to involuntary hospitalization for mental illness. The amassing and analysis of data will not resolve this conflict because the two sides view the problem from differing moral vantage points. Medical model adherents are influenced chiefly by utilitarian or consequentialist considerations, while the civil libertarians take more of a deontological or absolutist position. Opinions about such issues as hospitalization criteria of dangerousness versus medical necessity and the relative role of rights versus obligations and of autonomy versus paternalism can be seen largely to depend on such underlying value judgments. Neither side has a monopoly on truth or right in the question of involuntary hospitalization.

  16. How to make rapid eye movements “rapid”: the role of growth factors for muscle contractile properties

    PubMed Central

    Li, Tian; Feng, Cheng-Yuan

    2011-01-01

    Different muscle functions require different muscle contraction properties. Saccade-generating extraocular muscles (EOMs) are the fastest muscles in the human body, significantly faster than limb skeletal muscles. Muscle contraction speed is subjected to plasticity, i.e., contraction speed can be adjusted to serve different demands, but little is known about the molecular mechanisms that control contraction speed. Therefore, we examined whether myogenic growth factors modulate contractile properties, including twitch contraction time (onset of force to peak force) and half relaxation time (peak force to half relaxation). We examined effects of three muscle-derived growth factors: insulin-like growth factor 1 (IGF1), cardiotrophin-1 (CT1), and glial cell line-derived neurotrophic factor (GDNF). In gain-of-function experiments, CT1 or GDNF injected into the orbit shortened contraction time, and IGF1 or CT1 shortened half relaxation time. In loss-of-function experiments with binding proteins or neutralizing antibodies, elimination of endogenous IGFs prolonged both contraction time and half relaxation time, while eliminating endogenous GDNF prolonged contraction time, with no effect on half relaxation time. Elimination of endogenous IGFs or CT1, but not GDNF, significantly reduced contractile force. Thus, IGF1, CT1, and GDNF have partially overlapping but not identical effects on muscle contractile properties. Expression of these three growth factors was measured in chicken and/or rat EOMs by real-time PCR. The “fast” EOMs express significantly more message encoding these growth factors and their receptors than skeletal muscles with slower contractile properties. Taken together, these findings indicate that EOM contractile kinetics is regulated by the amount of myogenic growth factors available to the muscle. PMID:21279379

  17. Probing muscle myosin motor action: x-ray (m3 and m6) interference measurements report motor domain not lever arm movement.

    PubMed

    Knupp, Carlo; Offer, Gerald; Ranatunga, K W; Squire, John M

    2009-07-10

    The key question in understanding how force and movement are produced in muscle concerns the nature of the cyclic interaction of myosin molecules with actin filaments. The lever arm of the globular head of each myosin molecule is thought in some way to swing axially on the actin-attached motor domain, thus propelling the actin filament past the myosin filament. Recent X-ray diffraction studies of vertebrate muscle, especially those involving the analysis of interference effects between myosin head arrays in the two halves of the thick filaments, have been claimed to prove that the lever arm moves at the same time as the sliding of actin and myosin filaments in response to muscle length or force steps. It was suggested that the sliding of myosin and actin filaments, the level of force produced and the lever arm angle are all directly coupled and that other models of lever arm movement will not fit the X-ray data. Here, we show that, in addition to interference across the A-band, which must be occurring, the observed meridional M3 and M6 X-ray intensity changes can all be explained very well by the changing diffraction effects during filament sliding caused by heads stereospecifically attached to actin moving axially relative to a population of detached or non-stereospecifically attached heads that remain fixed in position relative to the myosin filament backbone. Crucially, and contrary to previous interpretations, the X-ray interference results provide little direct information about the position of the myosin head lever arm; they are, in fact, reporting relative motor domain movements. The implications of the new interpretation are briefly assessed.

  18. Muscle activity in the lower limbs during push-down movement with a new active-exercise apparatus for the leg

    PubMed Central

    Tanaka, Kenta; Kamada, Hiroshi; Shimizu, Yukiyo; Aikawa, Shizu; Irie, Shun; Ochiai, Naoyuki; Sakane, Masataka; Yamazaki, Masashi

    2016-01-01

    [Purpose] Lower-limb deep vein thrombosis is a complication of orthopedic surgery. A leg-exercise apparatus named “LEX” was developed as a novel active-exercise apparatus for deep vein thrombosis prevention. Muscle activity was evaluated to assess the effectiveness of exercise with LEX in the prevention. [Subjects] Eight healthy volunteers participated in this study. [Methods] Muscle activities were determined through electromyography during exercise with LEX [LEX (+)] and during active ankle movements [LEX (−)]. The end points were peak % maximum voluntary contraction and % integrated electromyogram of rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, gastrocnemius, and soleus. [Results] LEX (+) resulted in higher average values in all muscles except the tibialis anterior. Significant differences were noted in the peak of the biceps femoris and gastrocnemius and in the integrated electromyogram of the rectus femoris, vastus lateralis, gastrocnemius, and soleus. The LEX (+)/LEX (−) ratio of the peak was 2.2 for the biceps femoris and 2.0 for the gastrocnemius . The integrated electromyogram was 1.8 for the gastrocnemius, 1.5 for the rectus femoris, 1.4 for the vastus lateralis, and 1.2 for the soleus. [Conclusion] Higher muscle activity was observed with LEX (+). LEX might be a good tool for increasing lower-limb blood flow and deep vein thrombosis prevention. PMID:27134410

  19. The effect of abdominal bracing in combination with low extremity movements on changes in thickness of abdominal muscles and lumbar strength for low back pain.

    PubMed

    Lee, So Hee; Kim, Tae Hoon; Lee, Byoung Hee

    2014-01-01

    [Purpose] The purpose of this study was to investigate the effects of abdominal bracing with low extremity movement on changes in thickness of abdominal muscles and lumbar strength. [Subjects] Sixteen patients with chronic low back pain were randomly assigned to two groups: an abdominal bracing with active straight leg raise (ABSLR) group and abdominal bracing with ankle dorsiflexion (ABDF) group. [Methods] All subjects were evaluated for their abdominal muscle strength using a MedX Lumbar Extension Machine and thickness of external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) muscles using rehabilitative ultrasound imaging. Subjects in both groups were instructed to perform Abdominal bracing (AB). Simultaneously, those in the ABSLR group performed active SLR, and those in the ABDF group performed ankle dorsiflexion. [Results] In comparison between the ABSLR and ABDF groups, significant differences in the thickness of the IO and TrA muscles were observed after the intervention in the ABSLR group. Also, lumbar strength was showed a significant increase in both groups after interventions. [Conclusion] The results of this study demonstrated that ABSLR is a more effective method than ABDF for improvement of abdominal stabilization by increasing the thicknesses of the TrA and IO.

  20. The Effect of Abdominal Bracing in Combination with Low Extremity Movements on Changes in Thickness of Abdominal Muscles and Lumbar Strength for Low Back Pain

    PubMed Central

    Lee, So Hee; Kim, Tae Hoon; Lee, Byoung Hee

    2014-01-01

    [Purpose] The purpose of this study was to investigate the effects of abdominal bracing with low extremity movement on changes in thickness of abdominal muscles and lumbar strength. [Subjects] Sixteen patients with chronic low back pain were randomly assigned to two groups: an abdominal bracing with active straight leg raise (ABSLR) group and abdominal bracing with ankle dorsiflexion (ABDF) group. [Methods] All subjects were evaluated for their abdominal muscle strength using a MedX Lumbar Extension Machine and thickness of external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) muscles using rehabilitative ultrasound imaging. Subjects in both groups were instructed to perform Abdominal bracing (AB). Simultaneously, those in the ABSLR group performed active SLR, and those in the ABDF group performed ankle dorsiflexion. [Results] In comparison between the ABSLR and ABDF groups, significant differences in the thickness of the IO and TrA muscles were observed after the intervention in the ABSLR group. Also, lumbar strength was showed a significant increase in both groups after interventions. [Conclusion] The results of this study demonstrated that ABSLR is a more effective method than ABDF for improvement of abdominal stabilization by increasing the thicknesses of the TrA and IO. PMID:24567697

  1. Lower extremity muscle activation and function in progressive task-oriented training on the supplementary tilt table during stepping-like movements in patients with acute stroke hemiparesis.

    PubMed

    Kim, Chang-Yong; Lee, Jung-Sun; Kim, Hyeong-Dong; Kim, Junesun; Lee, In-Hak

    2015-06-01

    An effective and standardized method for applying a tilt table as a supplementary treatment in the early rehabilitation of stroke patients is still missing. The aim of this study was to determine the influence of progressive task-oriented training on the tilt table on the improvement in lower extremity (LE) muscle activation and clinical function in subjects with hemiplegia due to stroke. Thirty-nine subjects with acute stroke were randomly allocated to three groups; control group, tilt table group, and task-oriented training group on the tilt table, with 13 patients, respectively. All of the subjects received the routine therapy for half an hour, and subjects in the experimental groups additionally received training on two different tilt table applications for 20min a day, five times a week for three weeks. The effect of tilt table applications was assessed using the surface electromyography (EMG) analysis during stepping-like movements on the tilt table for LE muscle activation and clinical scores for function. Our results showed that there was a significantly greater increase in the EMG patterns of the extensors and flexors of the affected leg muscles during flexion and extension movements of both legs and clinical scores in patients undergoing the progressive task-oriented training on the tilt table compared to the other groups. These findings suggest that progressive task-oriented training on the tilt table can improve LE muscle activation and clinical scores of functional performance for early rehabilitation of subjects with acute stroke. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. 32 CFR 644.102 - Examples of involuntary acquisitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of involuntary acquisitions. While the Secretary of the Army and Secretary of the Air Force have no... Section 644.102 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL..., as evidence of the interest taken and as a protection against possible future claims of purchasers...

  3. 32 CFR 644.102 - Examples of involuntary acquisitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of involuntary acquisitions. While the Secretary of the Army and Secretary of the Air Force have no... Section 644.102 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL..., as evidence of the interest taken and as a protection against possible future claims of purchasers...

  4. 32 CFR 644.102 - Examples of involuntary acquisitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of involuntary acquisitions. While the Secretary of the Army and Secretary of the Air Force have no... Section 644.102 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL..., as evidence of the interest taken and as a protection against possible future claims of purchasers...

  5. 32 CFR 644.102 - Examples of involuntary acquisitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of involuntary acquisitions. While the Secretary of the Army and Secretary of the Air Force have no... Section 644.102 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL..., as evidence of the interest taken and as a protection against possible future claims of purchasers...

  6. Cognitive Control of Involuntary Distraction by Deviant Sounds

    ERIC Educational Resources Information Center

    Parmentier, Fabrice B. R.; Hebrero, Maria

    2013-01-01

    It is well established that a task-irrelevant sound (deviant sound) departing from an otherwise repetitive sequence of sounds (standard sounds) elicits an involuntary capture of attention and orienting response toward the deviant stimulus, resulting in the lengthening of response times in an ongoing task. Some have argued that this type of…

  7. 29 CFR 1625.9 - Prohibition of involuntary retirement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 4 2011-07-01 2011-07-01 false Prohibition of involuntary retirement. 1625.9 Section 1625... of 1986 by the Age Discrimination in Employment Amendments of 1986, Pub. L. 99-592, 100 Stat. 3342 (1986), which removed the age 70 limit. Section 12(a) provides that the Act's prohibitions shall...

  8. Cognitive Control of Involuntary Distraction by Deviant Sounds

    ERIC Educational Resources Information Center

    Parmentier, Fabrice B. R.; Hebrero, Maria

    2013-01-01

    It is well established that a task-irrelevant sound (deviant sound) departing from an otherwise repetitive sequence of sounds (standard sounds) elicits an involuntary capture of attention and orienting response toward the deviant stimulus, resulting in the lengthening of response times in an ongoing task. Some have argued that this type of…

  9. Involuntary Rehearsal of Second Languages in Beginning and Advanced Performers.

    ERIC Educational Resources Information Center

    Parr, Patricia Chapman; Krashen, Stephen D.

    1986-01-01

    Two studies of elementary, intermediate, and advanced second language learners indicated that involuntary rehearsal of second languages ("Din in the Head") is more frequently experienced by elementary and intermediate students and much less prevalent among advanced students, suggesting that the phenomenon is related to language…

  10. Intracellular calcium movements during excitation–contraction coupling in mammalian slow-twitch and fast-twitch muscle fibers

    PubMed Central

    Hollingworth, Stephen

    2012-01-01

    In skeletal muscle fibers, action potentials elicit contractions by releasing calcium ions (Ca2+) from the sarcoplasmic reticulum. Experiments on individual mouse muscle fibers micro-injected with a rapidly responding fluorescent Ca2+ indicator dye reveal that the amount of Ca2+ released is three- to fourfold larger in fast-twitch fibers than in slow-twitch fibers, and the proportion of the released Ca2+ that binds to troponin to activate contraction is substantially smaller. PMID:22450485

  11. [Involuntary placement and treatment of persons with mental health problems].

    PubMed

    Ikehara, Yoshikazu

    2013-01-01

    Involuntary placement and treatment of persons with mental health problems were initially discussed from the perspective of personal liberty. However, the autonomy of persons with mental health problems has been growing in importance as an issue of involuntary placement and treatment since the last part of the twentieth century, because the purpose of involuntary placement is not the deprivation of liberty but to provide adequate treatment under medical supervision. The UN Convention on the Rights of Persons with Disabilities (CRPD) adds a new perspective from non-discrimination and equality. Article 14 of CRPD states that "the existence of a disability shall in no case justify a deprivation of liberty." This provision should be construed from a perspective of non-discrimination. Conventional types of involuntary placement mainly based on dangerousness (UN-MI Principle 16-1a) and incompetency (UN-MI Principle16-1b) are not allowed by Article 14. There is a discussion on the difference between "mental disability" and "mental illness". Some people argue that CRPD should apply not to persons with mental illness, but to those with mental disabilities. However, CRPD does not provide a definition of "disability". It states that its definition is developing. ICF also mentions that ICD-10 and ICF should complement each other. Thus, CRPD should apply to the involuntary placement and treatment of persons with mental illness as well. It is clear that Article 14 intends to change the situation whereby persons who have been described using various terms, such as madness, lunacy, insanity, mental illness, mental disability, mental health problems, and users, are involuntarily hospitalized/placed. The significance of Article 14 will be lost if it cannot be applied to psychiatric hospitalization. From the perspective of non-discrimination, we have to universalize involuntary placement and treatment or completely abolish them. We cannot tolerate a situation where a type of

  12. How Were Eye Movements Recorded Before Yarbus?

    PubMed

    Wade, Nicholas J

    2015-01-01

    Alfred Yarbus introduced a new dimension of precision in recording how the eyes moved, either when attempts were made to keep them stationary or when scanning pictures. Movements of the eyes had been remarked upon for millennia, but recording how they move is a more recent preoccupation. Emphasis was initially placed on abnormalities of oculomotor function (like strabismus) before normal features were considered. The interest was in where the eyes moved to rather than determining how they got there. The most venerable technique for examining ocular stability involved comparing the relative motion between an afterimage and a real image. In the late 18th century, Wells compared afterimages generated before body rotation with real images observed following it when dizzy; he described both lateral and torsional nystagmus, thereby demonstrating the directional discontinuities in eye velocities. At around the same time Erasmus Darwin used afterimages as a means of demonstrating ocular instability when attempting to fixate steadily. However, the overriding concern in the 19th century was with eye position rather than eye movements. Thus, the characteristics of nystagmus were recorded before those of saccades and fixations. Eye movements during reading were described by Hering and by Lamare (working in Javal's laboratory) in 1879; both used similar techniques of listening (with tubes placed over the eyelids) to the sounds made during contractions of the extraocular muscles. Photographic records of eye movements during reading were made by Dodge early in the 20th century, and this stimulated research using a wider array of patterns. Eye movements over pictures were examined by Stratton and later by Buswell, who drew attention to the effects of instructions on the pattern of eye movements. In midcentury, attention shifted back to the stability of the eyes during fixation, with the emphasis on involuntary movements. The suction cap methods developed by Yarbus were applied

  13. Stereotypical movements and frontotemporal dementia.

    PubMed

    Mendez, Mario F; Shapira, Jill S; Miller, Bruce L

    2005-06-01

    Stereotypical movements are characteristic of autism or mental retardation but can also occur in patients with dementia, particularly frontotemporal dementia (FTD). In this study, we administered the Abnormal Involuntary Movement Scale (AIMS) to 18 patients with FTD and to 18 patients with the most common form of dementia, Alzheimer's disease (AD). The AIMS scores were gathered at the initial presentation of patients who had not received antipsychotic medications. Compared to the AD patients, the FTD patients had significantly more stereotypical movements, including frequent rubbing behaviors and some self-injurious acts. All the FTD patients with stereotypical movements had compulsive-like behaviors, suggesting a similar pathophysiologic cause, and most had a decrease in their stereotypical movements with the administration of sertraline, a serotonin selective reuptake inhibitor. (c) 2005 Movement Disorder Society.

  14. Evaluation of mirrored muscle activity in patients with Complex Regional Pain Syndrome.

    PubMed

    Bank, Paulina J M; Peper, C Lieke E; Marinus, Johan; Beek, Peter J; van Hilten, Jacobus J

    2014-10-01

    Motor dysfunction in Complex Regional Pain Syndrome (CRPS) has been associated with bilateral changes in central motor processing, suggesting abnormal coupling between the affected and unaffected limb. We evaluated the occurrence of involuntary muscle activity in a limb during voluntary movements of the contralateral limb (i.e., mirror activity) in unilaterally affected patients to examine disinhibition of contralateral motor activity in CRPS. Mirror activity was examined during unimanual rhythmic flexion-extension movements of the wrist through in-depth analysis of electromyography recordings from the passive arm in 20 CRPS patients and 40 controls. The number of mirror-epochs was comparable for both arms in both CRPS patients and controls. Mirror-epochs in the affected arm of patients were comparable to those in controls. Mirror-epochs in the unaffected arm were shorter and showed less resemblance (in terms of rhythm and timing) to activity of the homologous muscle in the moving arm compared to mirror-epochs in controls. No evidence for disinhibition of contralateral motor activity was found during unimanual movement. Although motor dysfunction in CRPS has been associated with bilateral changes in cortical motor processing, the present findings argue against disinhibition of interhemispheric projections to homologous muscles in the contralateral limb during unimanual movement. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  15. Epilepsia partialis continua of the abdominal muscles due to cerebrovascular disease.

    PubMed

    Ribeiro, Joana Jesus; Sousa, Mário; Teotónio, Rute; Bento, Conceição; Sales, Francisco

    2015-03-01

    Two elderly men, with previous history of cerebrovascular disease, were admitted to the emergency department due to focal motor status epilepticus with persistent myoclonic jerks of one side of the body. In both cases, the clinical picture evolved into a unilateral and isolated arrhythmic myoclonus of the abdominal muscles with preserved consciousness. These involuntary movements resolved with antiepileptic drugs. Although cerebrovascular disease is one of the most common causes of epilepsia partialis continua, reported cases in the literature with predominant abdominal involvement have a different aetiology. The neuroimaging and electroencephalographic findings showed a wide spectrum of different localizations and aetiologies associated with this particular type of epileptic seizure. Indeed, the pathophysiology of focal motor seizures involving the abdominal muscles is still a matter of discussion. In our second case, we present a patient with epilepsia partialis continua of the abdominal wall with an occipital focus, which, to the best of our knowledge, has not been previously reported. [Published with video sequences].

  16. Gluteal blood flow and oxygenation during electrical stimulation-induced muscle activation versus pressure relief movements in wheelchair users with a spinal cord injury.

    PubMed

    Smit, C A J; Zwinkels, M; van Dijk, T; de Groot, S; Stolwijk-Swuste, J M; Janssen, T W J

    2013-09-01

    Prolonged high ischial tuberosities pressure (IT pressure), decreased regional blood flow (BF) and oxygenation (%SO2) are risk factors for developing pressure ulcers (PUs) in patients with spinal cord injury (SCI). Electrical stimulation (ES)-induced gluteal and hamstring muscle activation may improve pressure distribution by changing the shape of the buttocks while sitting and also increase BF and %SO2. To compare acute effects of ES-induced gluteal and hamstring muscle activation with pressure relief movements (PRMs) on IT pressure, BF and %SO2. Twelve men with SCI performed PRMs - push-ups, bending forward and leaning sideward - and received surface ES (87±19 mA) to the gluteal and hamstring muscles while sitting in their wheelchair. Ischial tuberosities pressure was measured using a pressure mapping system; (sub)cutaneous BF and %SO2 were measured using reflection spectroscopy and laser Doppler, respectively. Compared with rest (156±26 mm Hg), IT pressure was significantly lower during all other conditions (push-ups 19±44; bending forward 56±33; leaning sideward 44±38; ES 67±45 mm Hg). For the whole group, all PRMs significantly augmented BF (+39 to -96%) and %SO2 (+6.0 to -7.9%-point), whereas ES-induced muscle activation did only for peak BF. In all, 63% of the participants showed an increased BF (average 52%) with ES. PRMs acutely reduced IT pressure and improved oxygenation and BF in SCI. The currently used ES method cannot replace PRMs, but it may be used additionally. ES-induced muscle activation is not as effective for acute pressure relief, but the frequency of stimulation is much higher than the performance of PRMs and can therefore be more effective in the long term.

  17. Dystonia and Paroxysmal Dyskinesias: Under-Recognized Movement Disorders in Domestic Animals? A Comparison with Human Dystonia/Paroxysmal Dyskinesias.

    PubMed

    Richter, Angelika; Hamann, Melanie; Wissel, Jörg; Volk, Holger A

    2015-01-01

    Dystonia is defined as a neurological syndrome characterized by involuntary sustained or intermittent muscle contractions causing twisting, often repetitive movements, and postures. Paroxysmal dyskinesias are episodic movement disorders encompassing dystonia, chorea, athetosis, and ballism in conscious individuals. Several decades of research have enhanced the understanding of the etiology of human dystonia and dyskinesias that are associated with dystonia, but the pathophysiology remains largely unknown. The spontaneous occurrence of hereditary dystonia and paroxysmal dyskinesia is well documented in rodents used as animal models in basic dystonia research. Several hyperkinetic movement disorders, described in dogs, horses and cattle, show similarities to these human movement disorders. Although dystonia is regarded as the third most common movement disorder in humans, it is often misdiagnosed because of the heterogeneity of etiology and clinical presentation. Since these conditions are poorly known in veterinary practice, their prevalence may be underestimated in veterinary medicine. In order to attract attention to these movement disorders, i.e., dystonia and paroxysmal dyskinesias associated with dystonia, and to enhance interest in translational research, this review gives a brief overview of the current literature regarding dystonia/paroxysmal dyskinesia in humans and summarizes similar hereditary movement disorders reported in domestic animals.

  18. Dystonia and Paroxysmal Dyskinesias: Under-Recognized Movement Disorders in Domestic Animals? A Comparison with Human Dystonia/Paroxysmal Dyskinesias

    PubMed Central

    Richter, Angelika; Hamann, Melanie; Wissel, Jörg; Volk, Holger A.

    2015-01-01

    Dystonia is defined as a neurological syndrome characterized by involuntary sustained or intermittent muscle contractions causing twisting, often repetitive movements, and postures. Paroxysmal dyskinesias are episodic movement disorders encompassing dystonia, chorea, athetosis, and ballism in conscious individuals. Several decades of research have enhanced the understanding of the etiology of human dystonia and dyskinesias that are associated with dystonia, but the pathophysiology remains largely unknown. The spontaneous occurrence of hereditary dystonia and paroxysmal dyskinesia is well documented in rodents used as animal models in basic dystonia research. Several hyperkinetic movement disorders, described in dogs, horses and cattle, show similarities to these human movement disorders. Although dystonia is regarded as the third most common movement disorder in humans, it is often misdiagnosed because of the heterogeneity of etiology and clinical presentation. Since these conditions are poorly known in veterinary practice, their prevalence may be underestimated in veterinary medicine. In order to attract attention to these movement disorders, i.e., dystonia and paroxysmal dyskinesias associated with dystonia, and to enhance interest in translational research, this review gives a brief overview of the current literature regarding dystonia/paroxysmal dyskinesia in humans and summarizes similar hereditary movement disorders reported in domestic animals. PMID:26664992

  19. Electromyography response of the iliocostalis lumborum muscle during flexion, extension and rotation movements of the trunk in orthostatic and seated position.

    PubMed

    de Moraes, A C; Bankoff, A D P

    2003-06-01

    The action of the column extensor muscles has been studied through in the electromyography in various corporal postures. We verified the electromyography responses of the iliocostalis lumborum muscle during various movements and positions. 12 individuals males, sedentary, between 36 and 52 years old (average 46.16), weighing an average of 79.66 kilos, and with an average height of 173.0 cm, all working as drivers were studied. Electromyography with six channels and surface electrodes was used. The electrodes were placed on the right side of the trunk in the direction of the third and fifth lumbar vertebrae ICL2 and ICL1 respectively). In orthostatic position, the flexion movement presented RMS 31.18 (+/- 5.73) in ICL1 and 58.10 (+/- 14.81) in ICL2; in extension the RMS 32.46 (+/- 9.17) in ICL1 and 55.31 (+/- 16.70) in ICL2; in homolateral rotation the RMS 30.05 (+/- 10.60) in ICL1 and 53.29 (+/- 19.70) in ICL2; in heterolateral rotation the RMS 24.76 (+/- 5.99) in ICL1 and 44.79 (+/- 15.26) in ICL2. In seated in a chair without a back, the flexion presented RMS 22.42 (+/- 2.89) in ICL1 and 43.39 (+/- 5.68) in ICL2; in extension the RMS 22.47 (+/- 1.95) in ICL1 and 41.28 (+/- 6.20) in ICL2; in homolateral rotation the RMS 24.10 (+/- 3.97) in ICL1 and 47.94 (+/- 5.80) in ICL2; in heterolateral rotation, the RMS 22.59 (+/- 1.95) in ICL1 and 43.15 (+/- 5.71) in ICL2. In the position seated on the ground, the flexion presented RMS 22.83 (+/- 3.00) in ICL1 and 50.99 (+/- 11.19) in ICL2; in extension the RMS 22.39 (+/- 3.22) in ICL1 and 46.44 (+/- 8.19) in ICL2. The results are expressed in RMS, indicating the participation of the iliocostalis lumborum muscle during the movements undertaken. The place identified as ICL2 presented action potential of greater amplitude than the place identified as ICL1 in all movements and positions.

  20. Inducing involuntary and voluntary mental time travel using a laboratory paradigm.

    PubMed

    Cole, Scott N; Staugaard, Søren R; Berntsen, Dorthe

    2016-04-01

    Although involuntary past and future mental time travel (MTT) has been examined outside the laboratory in diary studies, MTT has primarily been studied in the context of laboratory studies using voluntary construction tasks. In this study, we adapted and extended a paradigm previously used to elicit involuntary and voluntary memories (Schlagman & Kvavilashvili in Memory & Cognition, 36, 920-932, 2008). Our aim was - for the first time - to examine involuntary and voluntary future MTT under controlled laboratory conditions. The involuntary task involved a monotonous task that included potential cues for involuntary MTT. Temporal direction was manipulated between participants whereas retrieval mode was manipulated within participants. We replicated robust past-future differences, such as the future positivity bias. Additionally, we replicated key voluntary-involuntary differences: Involuntary future representations had similar characteristics as involuntary memories in that they were elicited faster, were more specific, and garnered more emotional impact than their voluntary counterparts. We also found that the future and past involuntary MTT led to both positive and negative mood impact, and that the valence of the impact was associated with the emotional valence of the event. This study advances scientific understanding of involuntary future representations in healthy populations and validates a laboratory paradigm that can be flexibly and systematically utilized to explore different characteristics of voluntary and involuntary MTT, which has not been possible within naturalistic paradigms.

  1. Hyperkinetic movement disorder in a child treated by globus pallidus stimulation.

    PubMed

    Sato, Ken; Nakagawa, Eiji; Saito, Yoshiaki; Komaki, Hirofumi; Sakuma, Hiroshi; Sugai, Kenji; Sasaki, Masayuki; Kaido, Takanobu; Nakama, Hideyuki; Otsuki, Taisuke

    2009-06-01

    We report herein the case of a 9-year-old girl with life-threatening hyperkinetic involuntary movement of unknown etiology. Medical treatment was ineffective for her stereotypy and choreoathetotic/ballistic movements, but bilateral stimulation of the globus pallidus immediately alleviated these symptoms. Pallidal deep-brain stimulation may be considered the therapy of choice for children with intractable hyperkinetic movement disorders.

  2. Submental sEMG and Hyoid Movement during Mendelsohn Maneuver, Effortful Swallow, and Expiratory Muscle Strength Training

    ERIC Educational Resources Information Center

    Wheeler-Hegland, Karen M.; Rosenbek, John C.; Sapienza, Christine M.

    2008-01-01

    Purpose: This study investigated the concurrent biomechanical and electromyographic properties of 2 swallow-specific tasks (effortful swallow and Mendelsohn maneuver) and 1 swallow-nonspecific (expiratory muscle strength training [EMST]) swallow therapy task in order to examine the differential effects of each on hyoid motion and associated…

  3. Submental sEMG and Hyoid Movement during Mendelsohn Maneuver, Effortful Swallow, and Expiratory Muscle Strength Training

    ERIC Educational Resources Information Center

    Wheeler-Hegland, Karen M.; Rosenbek, John C.; Sapienza, Christine M.

    2008-01-01

    Purpose: This study investigated the concurrent biomechanical and electromyographic properties of 2 swallow-specific tasks (effortful swallow and Mendelsohn maneuver) and 1 swallow-nonspecific (expiratory muscle strength training [EMST]) swallow therapy task in order to examine the differential effects of each on hyoid motion and associated…

  4. Inhibition by papaverine of calcium movements and tension in the smooth muscles of rat vas deferens and urinary bladder.

    PubMed Central

    Huddart, H; Langton, P D; Saad, K H

    1984-01-01

    Papaverine, up to 150 micron, was without effect on resting tension of vas deferens and urinary bladder smooth muscle strips, but caused a dose-dependent inhibition of the phasic component of the 100 mM-K contracture. At 150 micron, papaverine caused an 80 and 60% inhibition of phasic tension in vas deferens and urinary bladder muscle respectively. Papaverine caused a marked dose-dependent reduction in the tonic component of 100 mM-K contractures in both preparations. At 150 micron, papaverine often relaxed preparations below initial starting tension. Addition of 150 micron-papaverine to incubation media caused a fall of 25-30% in 45Ca uptake by both preparations. Papaverine at 150 micron caused a small fall in resting 45Ca efflux from vas deferens and a larger fall in efflux from bladder muscle. However, this papaverine concentration caused a large inhibition of the 45Ca uptake by and 45Ca efflux from both preparations when stimulated by high-K depolarization. Papaverine at 150 micron was without significant effect on Ca binding by either microsomes or mitochondria isolated from both vas deferens and urinary bladder smooth muscle. The main site of papaverine action appears to be on the Ca-influx mechanism responsible for regulating Ca entry during prolonged K depolarization. PMID:6737290

  5. Involuntary masturbation and hemiballismus after bilateral anterior cerebral artery infarction.

    PubMed

    Bejot, Yannick; Caillier, Marie; Osseby, Guy-Victor; Didi, Roy; Ben Salem, Douraied; Moreau, Thibault; Giroud, Maurice

    2008-02-01

    Ischemia of the areas supplied by the anterior cerebral artery is relatively uncommon. In addition, combined hemiballismus and masturbation have rarely been reported in patients with cerebrovascular disease. We describe herein a 62-year-old right-handed man simultaneously exhibiting right side hemiballismus and involuntary masturbation with the left hand after bilateral infarction of the anterior cerebral artery territory. Right side hemiballismus was related to the disruption of afferent fibers from the left frontal lobe to the left subthalamic nucleus. Involuntary masturbation using the left hand was exclusively linked to a callosal type of alien hand syndrome secondary to infarction of the right side of the anterior corpus callosum. After 2 weeks, these abnormal behaviours were completely extinguished. This report stresses the wide diversity of clinical manifestations observed after infarction of the anterior cerebral artery territory.

  6. Involuntary treatment of substance abuse disorders--impediments to success.

    PubMed

    Schottenfeld, R S

    1989-05-01

    Legal pressures currently account for between 40 and 70% of all referrals to community alcohol and drug treatment programs (Collins and Allison 1983; Dunham and Mauss 1982; Harford et al. 1976; Schnoll et al. 1980; Connecticut Alcohol and Drug Abuse Commission 1987). Changes in criminal statutes (Korcok 1986) and in commitment procedures for potentially dangerous patients (Bursten 1986; Herrington 1986) make it likely that even larger numbers of court-stipulated patients will enter treatment in the future. Although policies to divert drug or alcohol-dependent offenders from the criminal justice system into treatment are motivated by humane intentions as well as by practical considerations, in practice, involuntary treatment is problematic for all parties involved. Because many of the issues raised by court-stipulated treatment for alcohol or substance use disorders have been addressed only rarely and incompletely, this paper, on the basis of a review of enforced treatment in an outpatient alcohol and drug abuse treatment clinic, describes the problems encountered in enforced treatment, discusses the major impediments to successful coercive treatment, and proposes safeguards to preserve the integrity of involuntary treatment within the humanistic tradition of psychiatry. The focus of the paper is on involuntary treatment of alcohol-dependent patients or poly-drug users who deny problems related to substance use. Court-mandated, opiate-dependent patients differ from these patients in that they more often acknowledge problems related to addiction and withdrawal; consequently, they present different problems with regard to involuntary treatment. My hope is that by identifying some of the dilemmas faced by both clinicians and patients, some of the negative effects of coercive treatment may be avoided.

  7. Voluntary "involuntary" commitment--the briar-patch syndrome.

    PubMed

    Miller, R D

    1980-01-01

    Szasz and others have pointed out that many so-called voluntary admissions to mental hospitals have various elements of coercion involved, and are thus not truly voluntary. The author contends that the converse situation is also true, that many patients admitted under involuntary commitment papers arrange for their own commitments. Reasons for such choices are discussed in the context of a review of the literature and several case histories.

  8. Fetal muscle-type nicotinic acetylcholine receptor activation in TE-671 cells and inhibition of fetal movement in a day 40 pregnant goat model by optical isomers of the piperidine alkaloid coniine.

    PubMed

    Green, Benedict T; Lee, Stephen T; Welch, Kevin D; Pfister, James A; Panter, Kip E

    2013-01-01

    Coniine is an optically active toxic piperidine alkaloid and nicotinic acetylcholine receptor (nAChR) agonist found in poison hemlock (Conium maculatum L.). Coniine teratogenicity is hypothesized to be attributable to the binding, activation, and prolonged desensitization of fetal muscle-type nAChR, which results in the complete inhibition of fetal movement. However, pharmacological evidence of coniine actions at fetal muscle-type nAChR is lacking. The present study compared (-)-coniine, (+)-coniine, and nicotine for the ability to inhibit fetal movement in a day 40 pregnant goat model and in TE-671 cells that express fetal muscle-type nAChR. Furthermore, α-conotoxins (CTx) EI and GI were used to antagonize the actions of (+)- and (-)-coniine in TE-671 cells. (-)-Coniine was more effective at eliciting electrical changes in TE-671 cells and inhibiting fetal movement than was (+)-coniine, suggesting stereoselectivity by the receptor. The pyridine alkaloid nicotine did not inhibit fetal movement in a day 40 pregnant goat model, suggesting agonist specificity for the inhibition of fetal movement. Low concentrations of both CTxs potentiated the TE-671 cell response and higher concentrations of CTx EI, and GI antagonized the actions of both coniine enantiomers demonstrating concentration-dependent coagonism and selective antagonism. These results provide pharmacological evidence that the piperidine alkaloid coniine is acting at fetal muscle-type nAChR in a concentration-dependent manner.

  9. Dopamine modulates involuntary attention shifting and reorienting: an electromagnetic study.

    PubMed

    Kähkönen, Seppo; Ahveninen, Jyrki; Pekkonen, Eero; Kaakkola, Seppo; Huttunen, Juha; Ilmoniemi, Risto J; Jääskeläinen, Iiro P

    2002-12-01

    Dopaminergic function has been closely associated with attentional performance, but its precise role has remained elusive. Electrophysiological and behavioral methods were used to assess the effects of dopamine D2-receptor antagonist haloperidol on involuntary attention shifting using a randomized, double-blind, placebo-controlled cross-over design. Eleven subjects were instructed to discriminate equiprobable 200 and 400ms tones in a forced-choice reaction-time (RT) task during simultaneous measurement of whole-head magnetoencephalography and high-resolution electroencephalography. Occasional changes in task-irrelevant tone frequency (10% increase or decrease) caused marked distraction on behavioral performance, as shown by significant RT increases to deviant stimuli and subsequent standard tones. Furthermore, while the standard tones elicited distinct P1-N1-P2-N2-P3 waveforms, deviant tones elicited additional mismatch negativity (MMN), P3a, and reorienting negativity (RON) responses, indexing brain events associated with involuntary attention shifting. While haloperidol did not affect the source loci of the responses of magnetic N1 and MMN, the amplitude of the electric P3a and that of RON were significantly reduced and the latency of magnetic RON were delayed following haloperidol administration. The present results suggest that dopamine modulates involuntary attention shifting to task-irrelevant deviant events. It appears that dopamine may disrupt the subsequent re-orienting efforts to the relevant task after distraction.

  10. Primary health care nurses' promotion of involuntary migrant families' health.

    PubMed

    Samarasinghe, K; Fridlund, B; Arvidsson, B

    2010-06-01

    Involuntary migrant families in cultural transition face a number of challenges to their health and to family cohesion. Primary health care nurses (PHCNs) therefore play a vital role in the assessment and promotion of their health. The aim of this study was to describe the promotion of health in involuntary migrant families in cultural transition as conceptualized by Swedish PHCNs. Interviews were conducted with 34 strategically chosen PHCNs covering the entire range of the primary health care sector in two municipalities of Southern Sweden. A contextual approach with reference to phenomenography was used in interpreting the data. There are three qualitatively different descriptive categories epitomizing the characteristics of the PHCNs' promotion of health: (1) an ethnocentric approach promoting physical health of the individual, (2) an empathic approach promoting mental health of the individual in a family context, and (3) a holistic approach empowering the family to function well in everyday life. For nurses to promote involuntary migrant families'health in cultural transition, they need to adopt a holistic approach. Such an approach demands that nurses cooperate with other health care professionals and community authorities, and practise family-focused nursing; it also demands skills in intercultural communication paired with cultural self-awareness in interacting with these families. Adequate knowledge regarding these skills should therefore be included in the education of nurses, both at under- and at post-graduate level.

  11. A cardiorespiratory classifier of voluntary and involuntary electrodermal activity.

    PubMed

    Blain, Stefanie; Power, Sarah D; Sejdic, Ervin; Mihailidis, Alex; Chau, Tom

    2010-02-25

    Electrodermal reactions (EDRs) can be attributed to many origins, including spontaneous fluctuations of electrodermal activity (EDA) and stimuli such as deep inspirations, voluntary mental activity and startling events. In fields that use EDA as a measure of psychophysiological state, the fact that EDRs may be elicited from many different stimuli is often ignored. This study attempts to classify observed EDRs as voluntary (i.e., generated from intentional respiratory or mental activity) or involuntary (i.e., generated from startling events or spontaneous electrodermal fluctuations). Eight able-bodied participants were subjected to conditions that would cause a change in EDA: music imagery, startling noises, and deep inspirations. A user-centered cardiorespiratory classifier consisting of 1) an EDR detector, 2) a respiratory filter and 3) a cardiorespiratory filter was developed to automatically detect a participant's EDRs and to classify the origin of their stimulation as voluntary or involuntary. Detected EDRs were classified with a positive predictive value of 78%, a negative predictive value of 81% and an overall accuracy of 78%. Without the classifier, EDRs could only be correctly attributed as voluntary or involuntary with an accuracy of 50%. The proposed classifier may enable investigators to form more accurate interpretations of electrodermal activity as a measure of an individual's psychophysiological state.

  12. A cardiorespiratory classifier of voluntary and involuntary electrodermal activity

    PubMed Central

    2010-01-01

    Background Electrodermal reactions (EDRs) can be attributed to many origins, including spontaneous fluctuations of electrodermal activity (EDA) and stimuli such as deep inspirations, voluntary mental activity and startling events. In fields that use EDA as a measure of psychophysiological state, the fact that EDRs may be elicited from many different stimuli is often ignored. This study attempts to classify observed EDRs as voluntary (i.e., generated from intentional respiratory or mental activity) or involuntary (i.e., generated from startling events or spontaneous electrodermal fluctuations). Methods Eight able-bodied participants were subjected to conditions that would cause a change in EDA: music imagery, startling noises, and deep inspirations. A user-centered cardiorespiratory classifier consisting of 1) an EDR detector, 2) a respiratory filter and 3) a cardiorespiratory filter was developed to automatically detect a participant's EDRs and to classify the origin of their stimulation as voluntary or involuntary. Results Detected EDRs were classified with a positive predictive value of 78%, a negative predictive value of 81% and an overall accuracy of 78%. Without the classifier, EDRs could only be correctly attributed as voluntary or involuntary with an accuracy of 50%. Conclusions The proposed classifier may enable investigators to form more accurate interpretations of electrodermal activity as a measure of an individual's psychophysiological state. PMID:20184746

  13. Experience of action depends on intention, not body movement: an experiment on memory for mens rea.

    PubMed

    Jensen, Mads; Vagnoni, Eleonora; Overgaard, Morten; Haggard, Patrick

    2014-03-01

    How do we know whether our own actions were voluntary or involuntary? Intentional theories of sense of agency suggest that we consciously perceive the intentions that accompany our actions, but reconstructive theories suggest that we perceive our actions only through the body movements and other effects that they produce. Intentions would then be mere confabulations, and not bona fide experiences. Previous work on voluntary action has focused on immediate experiences of authorship, and few studies have considered memory for voluntary actions. We devised an experiment in which both voluntary action and involuntary movement always occurred at the same time, but could either involve the same hand (congruent condition), or different hands (incongruent condition). When signals from the voluntary and involuntary movements involved different hands, they could therefore potentially interfere in memory. We found that recall of a voluntary action was unaffected by an incongruent involuntary movement. In contrast, recall of an involuntary movement was strongly influenced by an incongruent voluntary action. Our results demonstrate an "intentional capture" of body movement by voluntary actions, in support of intentional theories of agency, but contrary to reconstructive theories. When asked to recall both actions and movements, people's responses are shaped by memory of what they intended to do, rather than by how their body moved. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Acute Effect of Biomechanical Muscle Stimulation on the Counter-Movement Vertical Jump Power and Velocity in Division I Football Players.

    PubMed

    Jacobson, Bert H; Monaghan, Taylor P; Sellers, John H; Conchola, Eric C; Pope, Zach K; Glass, Rob G

    2017-05-01

    Jacobson, BH, Monaghan, TP, Sellers, JH, Conchola, EC, Pope, ZK, and Glass, RG. Acute effect of biomechanical muscle stimulation on the counter-movement vertical jump power and velocity in division I football players. J Strength Cond Res 31(5): 1259-1264, 2017-Research regarding whole body vibration (WBV) largely supports such training augmentation in attempts to increase muscle strength and power. However, localized biomechanical vibration has not received the same attention. The purpose of this study was to assess peak and average power before and after acute vibration of selected lower-body sites in division I athletes. Twenty-one subjects were randomly assigned to 1 of 2 conditions using a cross-over design. Pretest consisted of a counter-movement vertical jump (VJ) followed by either localized vibration (30 Hz) to 4 selected lower-body areas or 4 minutes of moderately low-resistance stationary cycling (70 rpm). Vibration consisted of 1 minute bouts at each lower-leg site for a total of 4 minutes followed by an immediate post-test VJ. Repeated measures analysis of variance yielded no significant differences (p > 0.05) in either peak power or peak velocity. Similarly, no significant differences were found for average power and velocity between conditions. It should be noted that, while not significant, the vibration condition demonstrated an increase in peak power and velocity while the bike condition registered slight decreases. Comparing each of the post-VJ repetitions (1, 2, and 3) the vibration condition experienced significantly greater peak power and velocity from VJ 1 to VJ 3 compared with the bike condition which demonstrated no significant differences among the post-test VJs. These results yielded similar, although not statistically significant outcomes to previous studies using WBV. However, the novelty of selected site biomechanical vibration merits further investigation with respect to frequency, magnitude, and duration of vibration.

  15. The incidence of spontaneous movements (myoclonus) in dogs undergoing total intravenous anaesthesia with propofol.

    PubMed

    Cattai, Andrea; Rabozzi, Roberto; Natale, Valentina; Franci, Paolo

    2015-01-01

    To evaluate the incidence of myoclonus (involuntary movements during anaesthesia, unrelated to inadequate hypnosis or analgesia, and of sufficient severity to require treatment) in dogs anaesthetized with a TIVA of propofol with or without the use of fentanyl. Retrospective clinical study. Dogs, undergoing general anaesthesia for clinical procedures between January 2012 and January 2013 and subject to TIVA with propofol. A retrospective analysis reviewed the medical and anaesthetic records. Animals with existing or potential neurological or neuromuscular pathology in the anamnesis or upon clinical examination and cases with incomplete clinical records were excluded. Myoclonus was considered as involuntary muscle contractions which did not cease following a bolus administration of propofol or fentanyl and, due to their intensity and duration, made continuation of the procedure impracticable without other drug administration. Tremors, paddling or muscle spasms, explicable as insufficient hypnosis or analgesia, and transient excitatory phenomena only present during the awakening phase, were not considered as myoclonus. Out of a total of 492 dogs undergoing anaesthesia, six mixed breed dogs (1.2%), one male and five females, American Society of Anaesthesiologists (ASA) physical status I, median (range) weight 20.5 (7-37) kg and age 1.5 (1-5) years had myoclonus according to the aforementioned definition. In all subjects, myoclonus appeared within 20 minutes after induction of anaesthesia, and mainly involved the limb muscles. All subjects appeared to be in an adequate plane of anaesthesia before and during myoclonus. This study shows that 1.2% of dogs, undergoing TIVA with propofol with or without fentanyl administration, developed myoclonus, which required to be, and were treated successfully pharmacologically. The cause of this phenomenon is yet to be determined. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and

  16. The degree of facial movement following microvascular muscle transfer in pediatric facial reanimation depends on donor motor nerve axonal density.

    PubMed

    Snyder-Warwick, Alison K; Fattah, Adel Y; Zive, Leanne; Halliday, William; Borschel, Gregory H; Zuker, Ronald M

    2015-02-01

    Free functional muscle transfer to the face is a standard of facial animation. The contralateral facial nerve, via a cross-face nerve graft, provides spontaneous innervation for the transferred muscle, but is not universally available and has additional shortcomings. The motor nerve to the masseter provides an alternative innervation source. In this study, the authors compared donor nerve histomorphometry and clinical outcomes in a single patient population undergoing free muscle transfer to the face. Pediatric patients undergoing dynamic facial (re-)animation with intraoperative nerve biopsies and gracilis transfer to the face powered by either the contralateral facial nerve via a cross-face nerve graft or the motor nerve to the masseter were reviewed over a 7-year period. Myelinated nerve counts were assessed histomorphometrically, and functional outcomes were evaluated with the Scaled Measurement of Improvement in Lip Excursion software. From 2004 to 2011, 91 facial (re-)animation procedures satisfied study inclusion criteria. Average myelinated fiber counts were 6757 per mm2 in the donor facial nerve branch, 1647 per mm in the downstream cross-face nerve graft at the second stage, and 5289 per mm in the masseteric nerve. Reconstructions with either innervation source resulted in improvements in oral commissure excursion and smile symmetry, with the greatest amounts of oral commissure excursion noted in the masseteric nerve group. Facial (re-)animation procedures with use of the cross-face nerve graft or masseteric nerve are effective and result in symmetric smiles. The masseteric nerve provides a more robust innervation source and results in greater commissure excursion. Therapeutic, III.

  17. Effective one step-iterative fiducial marker-based compensation for involuntary motion in weight-bearing C-arm cone-beam CT scanning of knees

    NASA Astrophysics Data System (ADS)

    Choi, Jang-Hwan; Maier, Andreas; Berger, Martin; Fahrig, Rebecca

    2014-03-01

    We previously introduced three different fiducial marker-based correction methods (2D projection shifting, 2D projection warping, and 3D image warping) for patients' involuntary motion in the lower body during weight-bearing Carm CT scanning. The 3D warping method performed better than 2D methods since it could more accurately take into account the lower body motion in 3D. However, as the 3D warping method applies different rotational and translational movement to the reconstructed image for each projection frame, distance-related weightings were slightly twisted and thus result in overlaying background noise over the entire image. In order to suppress background noise and artifacts (e.g. metallic marker-caused streaks), the 3D warping method has been improved by incorporating bilateral filtering and a Landwebertype iteration in one step. A series of projection images of five healthy volunteers standing at various flexion angles were acquired using a C-arm cone-beam CT system with a flat panel. A horizontal scanning trajectory of the C-arm was calibrated to generate projection matrices. Using the projection matrices, the static reference marker coordinates in 3D were estimated and used for the improved 3D warping method. The improved 3D warping method effectively reduced background noise down below the noise level of 2D methods and also eliminated metal-generated streaks. Thus, improved visibility of soft tissue structures (e.g. fat and muscle) was achieved while maintaining sharp edges at bone-tissue interfaces. Any high resolution weight-bearing cone-beam CT system can apply this method for motion compensation.

  18. A Functional Magnetic Resonance Imaging Study of Head Movements in Cervical Dystonia

    PubMed Central

    Prudente, Cecília N.; Stilla, Randall; Singh, Shivangi; Buetefisch, Cathrin; Evatt, Marian; Factor, Stewart A.; Freeman, Alan; Hu, Xiaoping Philip; Hess, Ellen J.; Sathian, K.; Jinnah, H. A.

    2016-01-01

    Cervical dystonia (CD) is a neurological disorder characterized by abnormal movements and postures of the head. The brain regions responsible for these abnormal movements are not well understood, because most imaging techniques for assessing regional brain activity cannot be used when the head is moving. Recently, we mapped brain activation in healthy individuals using functional magnetic resonance imaging during isometric head rotation, when muscle contractions occur without actual head movements. In the current study, we used the same methods to explore the neural substrates for head movements in subjects with CD who had predominantly rotational abnormalities (torticollis). Isometric wrist extension was examined for comparison. Electromyography of neck and hand muscles ensured compliance with tasks during scanning, and any head motion was measured and corrected. Data were analyzed in three steps. First, we conducted within-group analyses to examine task-related activation patterns separately in subjects with CD and in healthy controls. Next, we directly compared task-related activation patterns between participants with CD and controls. Finally, considering that the abnormal head movements in CD occur in a consistently patterned direction for each individual, we conducted exploratory analyses that involved normalizing data according to the direction of rotational CD. The between-group comparisons failed to reveal any significant differences, but the normalization procedure in subjects with CD revealed that isometric head rotation in the direction of dystonic head rotation was associated with more activation in the ipsilateral anterior cerebellum, whereas isometric head rotation in the opposite direction was associated with more activity in sensorimotor cortex. These findings suggest that the cerebellum contributes to abnormal head rotation in CD, whereas regions in the cerebral cortex are involved in opposing the involuntary movements. PMID:27895619

  19. Passive or simulated displacement of one arm (but not its mirror reflection) modulates the involuntary motor behavior of the other arm.

    PubMed

    Brun, C; Metral, M; Chancel, M; Kavounoudias, A; Luyat, M; Guerraz, M

    2015-01-29

    Recent studies of both healthy and patient populations have cast doubt on the mirror paradigm's beneficial effect on motor behavior. Indeed, the voluntary arm displacement that accompanies reflection in the mirror may be the determining factor in terms of the motor behavior of the contralateral arm. The objective of the present study was to assess the respective effects of mirror reflection and arm displacement (whether real or simulated) on involuntary motor behavior of the contralateral arm following sustained, isometric contraction (Kohnstamm phenomenon). Our results revealed that (i) passive displacement of one arm (displacement of the left arm via a motorized manipulandum moving at 4°/s) influenced the velocity of the Kohnstamm phenomenon (forearm flexion occurring shortly after the cessation of muscle contraction) in the contralateral arm and (ii) mirror vision had no effect. Indeed, the velocity of the Kohnstamm phenomenon tended to be adjusted to match the velocity of the passive displacement of the other arm. In a second experiment, arm displacement was simulated by vibrating the triceps at 25, 50 or 75 Hz. Results showed that the velocity of the Kohnstamm phenomenon in one arm increased with the vibration frequency applied to the other arm. Our results revealed the occurrence of bimanual coupling because involuntary displacement of one arm was regulated by muscle-related information generated by the actual or simulated displacement of the other arm. In line with the literature data on voluntary motor behavior, our study failed to evidence an additional impact of mirror vision on involuntary motor behavior.

  20. Delineation of the movement disorders associated with FOXG1 mutations

    PubMed Central

    Papandreou, Apostolos; Schneider, Ruth B.; Augustine, Erika F.; Ng, Joanne; Mankad, Kshitij; Meyer, Esther; McTague, Amy; Ngoh, Adeline; Hemingway, Cheryl; Robinson, Robert; Varadkar, Sophia M.; Kinali, Maria; Salpietro, Vincenzo; O'Driscoll, Margaret C.; Basheer, S. Nigel; Webster, Richard I.; Mohammad, Shekeeb S.; Pula, Shpresa; McGowan, Marian; Trump, Natalie; Jenkins, Lucy; Elmslie, Frances; Scott, Richard H.; Hurst, Jane A.; Perez-Duenas, Belen; Paciorkowski, Alexander R.

    2016-01-01

    Objective: The primary objective of this research was to characterize the movement disorders associated with FOXG1 mutations. Methods: We identified patients with FOXG1 mutations who were referred to either a tertiary movement disorder clinic or tertiary epilepsy service and retrospectively reviewed medical records, clinical investigations, neuroimaging, and available video footage. We administered a telephone-based questionnaire regarding the functional impact of the movement disorders and perceived efficacy of treatment to the caregivers of one cohort of participants. Results: We identified 28 patients with FOXG1 mutations, of whom 6 had previously unreported mutations. A wide variety of movement disorders were identified, with dystonia, choreoathetosis, and orolingual/facial dyskinesias most commonly present. Ninety-three percent of patients had a mixed movement disorder phenotype. In contrast to the phenotype classically described with FOXG1 mutations, 4 patients with missense mutations had a milder phenotype, with independent ambulation, spoken language, and normocephaly. Hyperkinetic involuntary movements were a major clinical feature in these patients. Of the symptomatic treatments targeted to control abnormal involuntary movements, most did not emerge as clearly beneficial, although 4 patients had a caregiver-reported response to levodopa. Conclusions: Abnormal involuntary movements are a major feature of FOXG1 mutations. Our study delineates the spectrum of movement disorders and confirms an expanding clinical phenotype. Symptomatic treatment may be considered for severe or disabling cases, although further research regarding potential treatment strategies is necessary. PMID:27029630

  1. Acceleration of the sliding movement of actin filaments with the use of a non-motile mutant myosin in in vitro motility assays driven by skeletal muscle heavy meromyosin.

    PubMed

    Iwase, Kohei; Tanaka, Masateru; Hirose, Keiko; Uyeda, Taro Q P; Honda, Hajime

    2017-01-01

    We examined the movement of an actin filament sliding on a mixture of normal and genetically modified myosin molecules that were attached to a glass surface. For this purpose, we used a Dictyostelium G680V mutant myosin II whose release rates of Pi and ADP were highly suppressed relative to normal myosin, leading to a significantly extended life-time of the strongly bound state with actin and virtually no motility. When the mixing ratio of G680V mutant myosin II to skeletal muscle HMM (heavy myosin) was 0.01%, the actin filaments moved intermittently. When they moved, their sliding velocities were about two-fold faster than the velocity of skeletal HMM alone. Furthermore, sliding movements were also faster when the actin filaments were allowed to slide on skeletal muscle HMM-coated glass surfaces in the motility buffer solution containing G680V HMM. In this case no intermittent movement was observed. When the actin filaments used were copolymerized with a fusion protein consisting of Dictyostelium actin and Dictyostelium G680V myosin II motor domain, similar faster sliding movements were observed on skeletal muscle HMM-coated surfaces. The filament sliding velocities were about two-fold greater than the velocities of normal actin filaments. We found that the velocity of actin filaments sliding on skeletal muscle myosin molecules increased in the presence of a non-motile G680V mutant myosin motor.

  2. Examination of center of pressure displacement and muscle activity of the hip girdle muscles on lateral movement in the sitting position, focusing on kinematic features before and after the start of exercise

    PubMed Central

    Ikeda, Kouji; Suehiro, Kenji; Kizu, Akito; Kunieda, Hideki; Takasaki, Hirokazu; Suzuki, Toshiaki

    2017-01-01

    [Purpose] This study aimed to evaluate the kinematic characteristics at the start of lateral movement in the sitting position, for application in physical therapy. [Subjects and Methods] Eleven healthy male subjects (mean age, 24.8 ± 3.7 years) were included in the study after they provided informed consent. The electromyographic activities of the tensor fascia lata, gluteus medius, and rectus femoris, and the center of pressure (COP) displacement during lateral reach in the sitting position were measured. The task was recorded on video for analysis. [Results] In almost all subjects, before the beginning of the task, the electromyographic activity in the opposite side of each studied muscle was recorded, and the opposite and anterior displacement of the COP was observed. The video analysis revealed that all subjects showed lateral displacement of the thoracic part of the trunk after the start of the task. However, the lumbar region and pelvis maintained their starting positions. [Conclusion] COP displacement occurred in the reverse reaction before the task, and this involved the hip girdle muscles of the opposite side. A reverse reaction displaced the pelvis to the opposite side to ensure instability of posture through side tilting of the trunk at the beginning of the task. PMID:28356627

  3. Specific actions of gallium on contractile responses and /sup 45/Ca movements in rabbit aortic smooth muscle

    SciTech Connect

    Shetty, S.S.; Weiss, G.B.

    1986-03-01

    Gallium ion (Ga/sup + +/) dose-dependently (0.1-0.5 mM) inhibited contractions induced by norepinephrine (NE, 10/sup -6/ M) in rabbit aortic (and media-intimal) strips, but did not affect contractions elicited with high K/sup +/ (160 mM K/sup +/-substituted solution). The initial phasic portion of the NE-induced response was only slightly (< 10%) reduced, but the tonic portion of the response was completely inhibited by higher concentrations (0.3-0.5 mM) of Ga/sup + +/. In resting muscles, the equilibrated (90 min) /sup 45/Ca uptake was not altered by Ga/sup + +/. The effects of Ga/sup + +/ on /sup 45/Ca retained after a subsequent 60-min washout at 0.5/sup 0/C in an isosmotic (80.8 mM) La/sup + + +/ solution were also examined. Under conditions favoring low affinity Ca/sup + +/ uptake, /sup 45/Ca retention in control and K/sup +/-treated muscles was not changed by Ga/sup + +/, but the additional incremental /sup 45/Ca uptake associated with NE (in the presence of K/sup +/) was blocked. The efflux of /sup 45/Ca was transiently increased by Ga/sup + +/ only under conditions favoring detection of high affinity /sup 45/Ca release. High affinity La/sup + + +/-resistant /sup 45/Ca released by NE was not altered by Ga/sup + +/. Thus, Ga/sup + +/ appears to have a selective inhibitory action on NE-associated /sup 45/Ca uptake without affecting either resting and K/sup +/-induced /sup 45/Ca uptake or the /sup 45/Ca fraction released by Ne.

  4. Origin and development of muscle cramps.

    PubMed

    Minetto, Marco Alessandro; Holobar, Aleš; Botter, Alberto; Farina, Dario

    2013-01-01

    Cramps are sudden, involuntary, painful muscle contractions. Their pathophysiology remains poorly understood. One hypothesis is that cramps result from changes in motor neuron excitability (central origin). Another hypothesis is that they result from spontaneous discharges of the motor nerves (peripheral origin). The central origin hypothesis has been supported by recent experimental findings, whose implications for understanding cramp contractions are discussed.

  5. Respiratory rate can be modulated by long-loop muscular reflexes, a possible factor in involuntary cessation of apnea.

    PubMed

    Balestra, Costantino; Levenez, Morgan; Lafère, Pierre; Dachy, Bernard; Ezquer, Mikel; Germonpré, Peter

    2011-03-01

    The main limiting factors determining apnea time are generally considered to be related to blood and cerebrospinal fluid chemistry. Several physiological (adaptive) mechanisms and some psychologic parameters, such as motivation, are also known to increase apnea time. We wished to study the link between peripheral muscle fatigue, the concomitant alteration of long latency (transcortical) reflexes and respiratory control. Fatigue was induced in a small hand muscle (abductor pollicis brevis) (n = 11). This muscle is sufficiently small that its fatigue and the resulting production of metabolites are unlikely to alter whole-blood biochemistry. The Hoffmann reflex, an involuntary reaction to electrical stimulation of muscle afferent sensory fibreswas studied, as was the long latency reflex (LLR) using the Dueschl method in which electrical stimulation is superimposed on a slight voluntary contraction, Different fatiguing protocols were performed, and respiratory rate continuously recorded. The 'muscular metabolites increasing protocol' (at 50% maximum voluntary contraction, MVC) showed a significant dissociation between the decreases in the H-reflex and the LLR, compared to contraction at 25% MVC. This was associated with an increase in the respiratory rate to 148.25 (SD 11.37)% of control at 3 min (the maximum time the contraction could be sustained), whereas at 25% MVC, respiratory rate did not change during the contraction. This suggests a peripherally mediated, central input to the respiratory centres, triggering a powerful stimulus when metabolites accumulate in muscles. We believe this to be a possible mechanism terminating extreme breath holds.

  6. Muscle force generation and force control of finger movements in children with spastic hemiplegia during isometric tasks.

    PubMed

    Smits-Engelsman, B C; Rameckers, E A; Duysens, J

    2005-05-01

    Force control ability was investigated in 10 males and 10 females, between 5 and 15 years old with spastic hemiplegia (mild and moderate hand dysfunction), and an aged-matched control group (eight males, 12 females). An isometric force production task at five different levels of maximum voluntary contraction (MVC) was performed. Results showed that MVC generated with the affected hand (AH) was only one-third of that generated by the non-affected hand (NAH; p < 0.001), time to peak was almost twofold at the highest force level (p < 0.001), and the coefficient of variation was twice as high (p < 0.001). Results for the NAH did not differ from those of the control children. Correlations between clinical and experimental variables were significant for the relation between Ashworth score for elbow flexors, MVC and variability at the highest force level. In conclusion, the findings for the AH suggests that strength training should be considered for agonist spastic muscles.

  7. Nerve sources for facial reanimation with muscle transplant in patients with unilateral facial palsy: clinical analysis of 3 techniques.

    PubMed

    Faria, Jose Carlos M; Scopel, Gean P; Busnardo, Fabio F; Ferreira, Marcus C

    2007-07-01

    Ninety-one patients with long-standing unilateral facial palsy and submitted to reanimation of the face with muscle transplant were divided into 3 nonrandomized groups: group I: 2-stage facial reanimation, cross face followed by gracilis muscle transplant, 58 patients; group II: 1-stage reanimation with latissimus dorsi muscle transplant, 11 patients (a branch of the facial nerve on the nonparalyzed side of the face was used as the nerve source for reanimation in groups I and II); group III: 1-stage reanimation with gracilis muscle transplant and neural coaptation of the respective nerve and the ipsilateral masseteric branch of the trigeminal nerve, 22 patients. No microvascular complications were observed. The average interval between surgery and initial muscle contractions was 11.1 months, 7.2 months, and 3.7 months in group I, group II, and group III, respectively. The quality (intensity and shape) of the smile, voluntary or involuntary, obtained on the reanimated side in relation to the unaffected side was considered good or excellent in 53.4%, 54.5%, and 86.3% of the patients in groups I, II, and III, respectively. In group I, the average age of the patients with excellent or good results (19.8 + 10.5 years) was significantly lower than that of the patients with fair or poor results or absence of movement (36.5 + 13.3 years). The smile was considered emotional or involuntary in 34% of the patients in group I and 45% in group II. Most of the patients in each group were only able to produce "voluntary smiles". Crossed synkinesis with lip puckering was observed in 48% of the patients in group I and 90% in group II. The results obtained with 1-stage facial reanimation with masseteric nerve were more uniform and predictable than those obtained with the other techniques evaluated in this study.

  8. A Cycling Movement Based System for Real-Time Muscle Fatigue and Cardiac Stress Monitoring and Analysis.

    PubMed

    Chen, Szi-Wen; Liaw, Jiunn-Woei; Chang, Ya-Ju; Chan, Hsiao-Lung; Chiu, Li-Yu

    2015-01-01

    In this study, we defined a new parameter, referred to as the cardiac stress index (CSI), using a nonlinear detrended fluctuation analysis (DFA) of heart rate (HR). Our study aimed to incorporate the CSI into a cycling based fatigue monitoring system developed in our previous work so the muscle fatigue and cardiac stress can be both continuously and quantitatively assessed for subjects undergoing the cycling exercise. By collecting electrocardiogram (ECG) signals, the DFA scaling exponent α was evaluated on the RR time series extracted from a windowed ECG segment. We then obtained the running estimate of α by shifting a one-minute window by a step of 20 seconds so the CSI, defined as the percentage of all the less-than-one α values, can be synchronously updated every 20 seconds. Since the rating of perceived exertion (RPE) scale is considered as a convenient index which is commonly used to monitor subjective perceived exercise intensity, we then related the Borg RPE scale value to the CSI in order to investigate and quantitatively characterize the relationship between exercise-induced fatigue and cardiac stress. Twenty-two young healthy participants were recruited in our study. Each participant was asked to maintain a fixed pedaling speed at a constant load during the cycling exercise. Experimental results showed that a decrease in DFA scaling exponent α or an increase in CSI was observed during the exercise. In addition, the Borg RPE scale and CSI were positively correlated, suggesting that the factors due to cardiac stress might also contribute to fatigue state during physical exercise. Since the CSI can effectively quantify the cardiac stress status during physical exercise, our system may be used in sports medicine, or used by cardiologists who carried out stress tests for monitoring heart condition in patients with heart diseases.

  9. 26 CFR 1.1033(a)-3 - Involuntary conversion of principal residence.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 11 2011-04-01 2011-04-01 false Involuntary conversion of principal residence...)-3 Involuntary conversion of principal residence. Section 1033 shall apply in the case of property used by the taxpayer as his principal residence if the destruction, theft, seizure, requisition, or...

  10. 26 CFR 1.381(c)(13)-1 - Involuntary conversions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 4 2014-04-01 2014-04-01 false Involuntary conversions. 1.381(c)(13)-1 Section 1.381(c)(13)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... provisions of the Internal Revenue Code of 1954, is treated as though it were an involuntary...

  11. 26 CFR 1.1321-1 - Involuntary liquidation of lifo inventories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... evidence of the applicable inventory control figures for the beginning and the close of the taxable year... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Involuntary liquidation of lifo inventories. 1... (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Involuntary Liquidation and Replacement of Lifo...

  12. 26 CFR 1.1321-1 - Involuntary liquidation of lifo inventories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... evidence of the applicable inventory control figures for the beginning and the close of the taxable year... 26 Internal Revenue 11 2011-04-01 2011-04-01 false Involuntary liquidation of lifo inventories. 1... Inventories § 1.1321-1 Involuntary liquidation of lifo inventories. (a) Section 22(d)(6)(B) of the...

  13. Does Involuntary Mental Time Travel Make Sense in Prospective Teachers' Feelings and Behaviors during Lessons?

    ERIC Educational Resources Information Center

    Eren, Altay; Yesilbursa, Amanda

    2013-01-01

    This study examined the effects of involuntary mental time travel into the past and into the future on prospective teachers' feelings and behaviors during the period of a class hour. A total of 110 prospective teachers participated voluntarily in the study. The results of the present study showed that (a) the involuntary mental time travel into…

  14. 47 CFR 1.541 - Application for involuntary assignment of license or transfer of control.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Application for involuntary assignment of license or transfer of control. 1.541 Section 1.541 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Application for involuntary assignment of license or transfer of control. See § 73.3541....

  15. Involuntary Subordination and Its Relation to Personality, Mood, and Submissive Behavior

    ERIC Educational Resources Information Center

    Sturman, Edward D.

    2011-01-01

    According to social rank theory, involuntary subordination may be adaptive in species that compete for resources as a mechanism to switch off fighting behaviors when loss is imminent (thus saving an organism from injury). In humans, major depression is thought to occur when involuntary subordination becomes prolonged. The present study sought to…

  16. Treatment or Involuntary Euthanasia for Severely Handicapped Newborns: Issues of Philosophy and Public Policy.

    ERIC Educational Resources Information Center

    Powell, T. Hennessy; And Others

    1982-01-01

    Recent reports have indicated that parents and/or physicians occasionally decide not to provide life-sustaining treatment (referred to as involuntary euthanasia), thus ensuring that the severely handicapped newborn will die. The issues involved relative to treatment or involuntary euthanasia are reviewed from two opposing perspectives…

  17. Treatment or Involuntary Euthanasia for Severely Handicapped Newborns: Issues of Philosophy and Public Policy.

    ERIC Educational Resources Information Center

    Powell, T. Hennessy; And Others

    1982-01-01

    Recent reports have indicated that parents and/or physicians occasionally decide not to provide life-sustaining treatment (referred to as involuntary euthanasia), thus ensuring that the severely handicapped newborn will die. The issues involved relative to treatment or involuntary euthanasia are reviewed from two opposing perspectives…

  18. The Involuntary Treatment of Adolescent Psychiatric Inpatients--A Nation-Wide Survey from Finland

    ERIC Educational Resources Information Center

    Ellila, Heikki Toivo; Sourander, Andre; Valimaki, Maritta; Warne, Tony; Kaivosoja, Matti

    2008-01-01

    This national cross-sectional study investigates the prevalence rates, regional differences and factors associated with the involuntary inpatient treatment of adolescents in Finland on a chosen day in 2000. The proportion of inpatients with involuntary legal status was 29.5% (n=82) giving a prevalence rate of 2.5 per 10,000/12-17 years old…

  19. Involuntary Subordination and Its Relation to Personality, Mood, and Submissive Behavior

    ERIC Educational Resources Information Center

    Sturman, Edward D.

    2011-01-01

    According to social rank theory, involuntary subordination may be adaptive in species that compete for resources as a mechanism to switch off fighting behaviors when loss is imminent (thus saving an organism from injury). In humans, major depression is thought to occur when involuntary subordination becomes prolonged. The present study sought to…

  20. The Effects of Involuntary Residential Relocation on Institutionalized Populations: A Review.

    ERIC Educational Resources Information Center

    Heller, Tamar

    This paper reviews the research of the effects of involuntary residential relocation on the personal adjustment of institutionalized individuals, i.e., the institutionalized elderly, mentally ill, and mentally retarded. Discrepant findings in studies of involuntary relocation are discussed in terms of the transferees' personal characteristics, the…

  1. 47 CFR 64.1512 - Involuntary blocking of pay-per-call services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Involuntary blocking of pay-per-call services... CARRIER SERVICES (CONTINUED) MISCELLANEOUS RULES RELATING TO COMMON CARRIERS Interstate Pay-Per-Call and Other Information Services § 64.1512 Involuntary blocking of pay-per-call services. Nothing in...

  2. A Low-Correlation Resting State of the Striatum during Cortical Avalanches and Its Role in Movement Suppression

    PubMed Central

    Plenz, Dietmar

    2016-01-01

    During quiet resting behavior, involuntary movements are suppressed. Such movement control is attributed to cortico-basal ganglia loops, yet population dynamics within these loops during resting and their relation to involuntary movements are not well characterized. Here, we show by recording cortical and striatal ongoing population activity in awake rats during quiet resting that intrastriatal inhibition maintains a low-correlation striatal resting state in the presence of cortical neuronal avalanches. Involuntary movements arise from disturbed striatal resting activity through two different population dynamics. Nonselectively reducing intrastriatal γ-aminobutyric acid (GABA) receptor-A inhibition synchronizes striatal dynamics, leading to involuntary movements at low rate. In contrast, reducing striatal interneuron (IN)-mediated inhibition maintains decorrelation and induces intermittent involuntary movements at high rate. This latter scenario was highly effective in modulating cortical dynamics at a subsecond timescale. To distinguish intrastriatal processing from loop dynamics, cortex-striatum-midbrain cultures, which lack feedback to cortex, were used. Cortical avalanches in vitro were accompanied by low-correlated resting activity in the striatum and nonselective reduction in striatal inhibition synchronized striatal neurons similar to in vivo. Importantly, reduction of inhibition from striatal INs maintained low correlations in the striatum while reorganizing functional connectivities among striatal neurons. Our results demonstrate the importance of two major striatal microcircuits in distinctly regulating striatal and cortical resting state dynamics. These findings suggest that specific functional connectivities of the striatum that are maintained by local inhibition are important in movement control. PMID:27923040

  3. A Low-Correlation Resting State of the Striatum during Cortical Avalanches and Its Role in Movement Suppression.

    PubMed

    Klaus, Andreas; Plenz, Dietmar

    2016-12-01

    During quiet resting behavior, involuntary movements are suppressed. Such movement control is attributed to cortico-basal ganglia loops, yet population dynamics within these loops during resting and their relation to involuntary movements are not well characterized. Here, we show by recording cortical and striatal ongoing population activity in awake rats during quiet resting that intrastriatal inhibition maintains a low-correlation striatal resting state in the presence of cortical neuronal avalanches. Involuntary movements arise from disturbed striatal resting activity through two different population dynamics. Nonselectively reducing intrastriatal γ-aminobutyric acid (GABA) receptor-A inhibition synchronizes striatal dynamics, leading to involuntary movements at low rate. In contrast, reducing striatal interneuron (IN)-mediated inhibition maintains decorrelation and induces intermittent involuntary movements at high rate. This latter scenario was highly effective in modulating cortical dynamics at a subsecond timescale. To distinguish intrastriatal processing from loop dynamics, cortex-striatum-midbrain cultures, which lack feedback to cortex, were used. Cortical avalanches in vitro were accompanied by low-correlated resting activity in the striatum and nonselective reduction in striatal inhibition synchronized striatal neurons similar to in vivo. Importantly, reduction of inhibition from striatal INs maintained low correlations in the striatum while reorganizing functional connectivities among striatal neurons. Our results demonstrate the importance of two major striatal microcircuits in distinctly regulating striatal and cortical resting state dynamics. These findings suggest that specific functional connectivities of the striatum that are maintained by local inhibition are important in movement control.

  4. Post-stroke Movement Disorders: Clinical Manifestations and Pharmacological Management

    PubMed Central

    Siniscalchi, Antonio; Gallelli, Luca; Labate, Angelo; Malferrari, Giovanni; Palleria, Caterina; Sarro, Giovambattista De

    2012-01-01

    Involuntary abnormal movements have been reported after ischaemic and haemorrhagic stroke. Post stroke movement disorders can appear as acute or delayed sequel. At the moment, for many of these disorders the knowledge of pharmacological treatment is still inadequate. Dopaminergic and GABAergic systems may be mainly involved in post-stroke movement disorders. This article provides a review on drugs commonly used in post-stroke movement disorders, given that some post-stroke movement disorders have shown a partial benefit with pharmacological approach. PMID:23449883

  5. The Frequency of Involuntary Autobiographical Memories and Future Thoughts in Relation to Daydreaming, Emotional Distress, and Age

    PubMed Central

    Berntsen, Dorthe; Rubin, David C.; Salgado, Sinue

    2015-01-01

    We introduce a new scale, the Involuntary Autobiographical Memory Inventory (IAMI), for measuring the frequency of involuntary autobiographical memories and involuntary future thoughts. Using the scale in relation to other psychometric and demographic measures provided three important, novel findings. First, the frequency of involuntary and voluntary memories and future thoughts are similarly related to general measures of emotional distress. This challenges the idea that the involuntary mode is uniquely associated with emotional distress. Second, the frequency of involuntary autobiographical remembering does not decline with age, whereas measures of daydreaming, suppression of unwanted thoughts and dissociative experiences all do. Thus, involuntary autobiographical remembering relates differently to aging than daydreaming and other forms of spontaneous and uncontrollable thoughts. Third, unlike involuntary autobiographical remembering, the frequency of future thoughts does decrease with age. This finding underscores the need for examining past and future mental time travel in relation to aging and life span development. PMID:26241025

  6. The frequency of involuntary autobiographical memories and future thoughts in relation to daydreaming, emotional distress, and age.

    PubMed

    Berntsen, Dorthe; Rubin, David C; Salgado, Sinue

    2015-11-01

    We introduce a new scale, the Involuntary Autobiographical Memory Inventory (IAMI), for measuring the frequency of involuntary autobiographical memories and involuntary future thoughts. Using the scale in relation to other psychometric and demographic measures provided three important, novel findings. First, the frequency of involuntary and voluntary memories and future thoughts are similarly related to general measures of emotional distress. This challenges the idea that the involuntary mode is uniquely associated with emotional distress. Second, the frequency of involuntary autobiographical remembering does not decline with age, whereas measures of daydreaming, suppression of unwanted thoughts and dissociative experiences all do. Thus, involuntary autobiographical remembering relates differently to aging than daydreaming and other forms of spontaneous and uncontrollable thoughts. Third, unlike involuntary autobiographical remembering, the frequency of future thoughts does decrease with age. This finding underscores the need for examining past and future mental time travel in relation to aging and life span development. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. The Relationship of Saccadic Eye Movements to Reading Disabilities. Final Report.

    ERIC Educational Resources Information Center

    Ross, Alan O.

    Saccadic (small, rapid, and apparently involuntary) eye movements of 14 children (7- to 12-years-old) with reading difficulties and of 14 normal readers were compared before and after the problem readers underwent a 7-month individual tutoring program. At pretesting the problem readers showed a rate of eye movements that was markedly lower than…

  8. A damped oscillation in the intramembranous charge movement and calcium release flux of frog skeletal muscle fibers.

    PubMed

    Shirokova, N; Pizarro, G; Ríos, E

    1994-09-01

    Asymmetric membrane currents and calcium transients were recorded simultaneously from cut segments of frog skeletal muscle fibers voltage clamped in a double Vaseline-gap chamber in the presence of high concentration of EGTA intracellularly. An inward phase of asymmetric currents following the hump component was observed in all fibers during the depolarization pulse to selected voltages (congruent to -45 mV). The average value of the peak inward current was 0.1 A/F (SEM = 0.01, n = 18), and the time at which it occurred was 34 ms (SEM = 1.8, n = 18). A second delayed outward phase of asymmetric current was observed after the inward phase, in those experiments in which hump component and inward phase were large. It peaked at more variable time (between 60 and 130 ms) with amplitude 0.02 A/F (SEM = 0.003, n = 11). The transmembrane voltage during a pulse, measured with a glass microelectrode, reached its steady value in less than 10 ms and showed no oscillations. The potential was steady at the time when the delayed component of asymmetric current occurred. ON and OFF charge transfers were equal for all pulse durations. The inward phase moved 1.4 nC/microF charge (SEM = 0.8, n = 6), or about one third of the final value of charge mobilized by these small pulses, and the second outward phase moved 0.7 nC/microF (SEM = 0.8, n = 6), bringing back about half of the charge moved during the inward phase. When repolarization intersected the peak of the inward phase, the OFF charge transfer was independent of the repolarization voltage in the range -60 to -90 mV. When both pre- and post-pulse voltages were changed between -120 mV and -60 mV, the equality of ON and OFF transfers of charge persisted, although they changed from 113 to 81% of their value at -90 mV. The three delayed phases in asymmetric current were also observed in experiments in which the extracellular solution contained Cd2+, La3+ and no Ca2+. Large increases in intracellular [Cl-] were imposed, and had no

  9. Comparison between an automatic and a visual scoring method of the chin muscle tone during rapid eye movement sleep.

    PubMed

    Ferri, Raffaele; Gagnon, Jean-François; Postuma, Ronald B; Rundo, Francesco; Montplaisir, Jacques Y

    2014-06-01

    To compare two different methods, one visual and the other automatic, for the quantification of rapid eye movement (REM) sleep without atonia (RSWA) in the diagnosis of REM sleep behavior disorder (RBD). Seventy-four RBD patients (mean age, 62.14±9.67 years) and 75 normal controls (mean age, 61.04±12.13 years) underwent one night video-polysomnographic recording. The chin electromyogram (EMG) during REM sleep was analyzed by means of a previously published visual method quantifying the percentage of 30s epochs scored as tonic (abnormal, > or =30%) and that of 2s mini-epochs containing phasic EMG events (abnormal, > or =15%). For the computer quantitative analysis we used the automatic scoring algorithm known as the atonia index (abnormal, <0.8). The percentage correct classification, sensitivity, specificity, and Cohen kappa were calculated. The atonia index correctly classified 82.6% of subjects, similar to the percentage of correct classifications with individual components of the visual analysis (83.2% each for tonic and phasic), and the combined visual parameters (85.9%). The sensitivity and specificity of automatic analysis (84% and 81%) was similar to the combined visual analysis (89% and 83%). The correlation coefficient between the automatic atonia index and the percentage of visual tonic EMG was high (r = -0.886, P<0.00001), with moderately high correlation with the percentage of phasic EMG (r = -0.690, P<0.00001). The agreement between atonia index and the visual parameters (individual or combined) was approximately 85% with Cohen's kappa, ranging from 0.638 to 0.693. Sensitivity, specificity, and correct classifications were high with both methods. Moreover, there was general agreement between methods, with Cohen's kappa values in the 'good' range. Given the considerable practical advantages of automatic quantification of REM atonia, automatic quantification may be a useful alternative to visual scoring methods in otherwise uncomplicated polysomnograms

  10. Destabilizing effects of visual environment motions simulating eye movements or head movements

    NASA Technical Reports Server (NTRS)

    White, Keith D.; Shuman, D.; Krantz, J. H.; Woods, C. B.; Kuntz, L. A.

    1991-01-01

    In the present paper, we explore effects on the human of exposure to a visual virtual environment which has been enslaved to simulate the human user's head movements or eye movements. Specifically, we have studied the capacity of our experimental subjects to maintain stable spatial orientation in the context of moving their entire visible surroundings by using the parameters of the subjects' natural movements. Our index of the subjects' spatial orientation was the extent of involuntary sways of the body while attempting to stand still, as measured by translations and rotations of the head. We also observed, informally, their symptoms of motion sickness.

  11. Deaths in Canada from lung cancer due to involuntary smoking.

    PubMed Central

    Wigle, D T; Collishaw, N E; Kirkbride, J; Mao, Y

    1987-01-01

    Recently published evidence indicates that involuntary smoking causes an increased risk of lung cancer among nonsmokers. Information was compiled on the proportion of people who had never smoked among victims of lung cancer, the risk of lung cancer for nonsmokers married to smokers and the prevalence of such exposure. On the basis of these data we estimate that 50 to 60 of the deaths from lung cancer in Canada in 1985 among people who had never smoked were caused by spousal smoking; about 90% occurred in women. The total number of deaths from lung cancer attributable to exposure to tobacco smoke from spouses and other sources (mainly the workplace) was derived by applying estimated age- and sex-specific rates of death from lung cancer attributable to such exposure to the population of Canadians who have never smoked; about 330 deaths from lung cancer annually are attributable to such exposure. PMID:3567810

  12. Positive involuntary autobiographical memories: You first have to live them

    PubMed Central

    Clark, Ian A.; Mackay, Clare E.; Holmes, Emily A.

    2013-01-01

    Involuntary autobiographical memories (IAMs) are typically discussed in the context of negative memories such as trauma ‘flashbacks’. However, IAMs occur frequently in everyday life and are predominantly positive. In spite of this, surprisingly little is known about how such positive IAMs arise. The trauma film paradigm is often used to generate negative IAMs. Recently an equivalent positive film was developed inducing positive IAMs (Davies, Malik, Pictet, Blackwell, & Holmes, 2012). The current study is the first to investigate which variables (emotional reaction to the film; recognition memory of the film; participant characteristics) would best predict the frequency of positive IAMs. Higher levels of positive mood change to the film were significantly associated with the number of positive IAMs recorded in the subsequent week. Results demonstrate the importance of positive emotional reaction at the time of an event for subsequent positive IAMs. PMID:23416539

  13. The Reappearance Hypothesis Revisited: Recurrent Involuntary Memories after Traumatic Events and in Everyday Life

    PubMed Central

    Berntsen, Dorthe; Rubin, David C.

    2011-01-01

    Recurrent involuntary memories are autobiographical memories that come to mind with no preceding retrieval attempt and that are subjectively experienced as being repetitive. Clinically, they are classified as a symptom of Posttraumatic Stress Disorder (PTSD). The present work is the first to systematically examine recurrent involuntary memories outside clinical settings. Study 1 examines recurrent involuntary memories among survivors of the tsunami catastrophe in Southeast Asia in 2004. Study 2 examines recurrent involuntary memories in a large general population. Study 3 examines whether the contents of recurrent involuntary memories recorded in a diary study are duplicates of, or differ from, one another. We show that recurrent involuntary memories are not limited to clinical populations or to emotionally negative experiences, that they typically do not come to mind in a fixed and unchangeable form, and that they show the same pattern regarding accessibility as autobiographical memories in general. We argue that recurrent involuntary memories after traumas and in everyday life can be explained in terms of general and well-established mechanisms of autobiographical memory. PMID:18426073

  14. Spontaneous or intentional? Involuntary versus voluntary episodic memories in older and younger adults.

    PubMed

    Berntsen, Dorthe; Rasmussen, Anne S; Miles, Amanda N; Nielsen, Niels Peter; Ramsgaard, Stine B

    2017-03-01

    Involuntary episodic memories are memories of past events that come to mind with no preceding attempt of retrieval. Such memories have received little attention in relation to aging compared with voluntary episodic memories (i.e., intentionally retrieved memories of past events). It is well documented that older compared with younger adults have reduced access to episodic memories, when retrieval is voluntary, but little is known about their involuntary episodic recall. Recent evidence suggests that involuntary autobiographical memories are at least as frequent as voluntary autobiographical memories in daily life, but this research has been limited to younger adults. Here older and younger adults recorded involuntary and voluntary episodic memories in relation to a film of a simulated event (Study 1) and during a normal day in their lives (Study 2). Acros