Short-term variability in amplitude and motor topography of whole-body involuntary movements in Parkinson's disease dyskinesias and in Huntington's chorea.

PubMed

Fenney, Alison; Jog, Mandar S; Duval, Christian

2008-02-01

Clinical observations have noted variability in amplitude of levodopa-induced dyskinesias (LID) in Parkinson's disease (PD) and chorea in Huntington's disease (HD) during the day. However, no studies have examined whether both the amplitude and body location (motor topography) of whole-body involuntary movement (WBIM) varied over short periods of time (seconds or minutes), which may have a distinct and significant effect on how disruptive these WBIM may be. The present study quantified the variability of WBIM amplitude and motor topography in patients with PD having LID and in patients with HD having chorea. WBIM was quantified using the MotionMonitor magnetic motion tracker system. Five patients in each group were tested in two conditions: sitting and standing. WBIM increased from sitting to standing, more so in choreic patients. WBIM varied from 17% to 102% of total WBIM amplitude. Chorea tended to present with greater variability than LID in absolute terms in the standing condition, but not when the mean WBIM amplitude was taken into consideration. Motor topography of WBIM also varied more in the HD group, but mostly in the seated condition where more limbs were free to move. Neither group expressed any laterality of involuntary movement, with amplitude being equally distributed on both sides of the body. Results show significant short-term variability in amplitude of chorea and LID, as well as, variability in location of these involuntary movements, illustrating the complexity of the adaptations required to live and be active with involuntary movements such as HD chorea or PD dyskinesias.

[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.

Interhemispheric Control of Unilateral Movement

PubMed Central

Beaulé, Vincent; Tremblay, Sara; Théoret, Hugo

2012-01-01

To perform strictly unilateral movements, the brain relies on a large cortical and subcortical network. This network enables healthy adults to perform complex unimanual motor tasks without the activation of contralateral muscles. However, mirror movements (involuntary movements in ipsilateral muscles that can accompany intended movement) can be seen in healthy individuals if a task is complex or fatiguing, in childhood, and with increasing age. Lateralization of movement depends on complex interhemispheric communication between cortical (i.e., dorsal premotor cortex, supplementary motor area) and subcortical (i.e., basal ganglia) areas, probably coursing through the corpus callosum (CC). Here, we will focus on transcallosal interhemispheric inhibition (IHI), which facilitates complex unilateral movements and appears to play an important role in handedness, pathological conditions such as Parkinson's disease, and stroke recovery. PMID:23304559

Involuntary expiratory phonation as a dose-related consequence of L-dopa therapy in a patient with Parkinson's disease.

PubMed

Ishii, Kosuke; Kumada, Masanobu; Ueki, Akira; Yamamoto, Masanori; Hirose, Hajime

2003-12-01

We report a case of involuntary phonation caused by abnormal vocal cord movements during expiration in a patient with Parkinson's disease. A 60-year-old woman had been treated for parkinsonism at the outpatient clinic of the Department of Neurology since August 1999. She began to groan involuntarily in the daytime in September 2001. She could not eat well while groaning. Stridor was not noted during sleep at night. Endoscopic examination of the larynx revealed insufficient abduction of the bilateral vocal cords, although the glottis was not so small as to cause stridor during inspiration. During expiration, however, the vocal cords adducted, resulting in the involuntary production of voice. Electromyography showed an increase in the activity of the thyroarytenoid and lateral cricoarytenoid muscles. This muscle activity was further enhanced during inspiration. The involuntary phonation disappeared when the patient's dose of L-dopa was decreased, although she had a decrease in her systemic mobility as well. When the dose of L-dopa was increased to the therapeutic level, involuntary phonation recurred, and her voluntary systemic activity improved. In the present case, it was considered that excessive dopaminergic denervation occurred in the nerve innervating the laryngeal adductors. Involuntary voice appeared to be produced by hypertonus of the laryngeal adductors because of a lowering in the threshold level for L-dopa, even though the drug was administered at the usual dose.

Association between involuntary weight loss with low muscle mass and health-related quality of life in community-dwelling older adults: Nationwide surveys (KNHANES 2008-2011).

PubMed

Kim, Miji; Kim, Junghoon; Won, Chang Won

2018-06-01

To investigate the relationship between involuntary weight loss with low muscle mass and health-related quality of life in a large representative sample of older adults. A nationwide cross-sectional study based on data from the Korea National Health and Nutritional Examination Survey, 2008 to 2011. Study participants included 2249 individuals aged ≥70 years. The participants reported an unintentional weight loss >3 kg in the past year. Appendicular lean mass was measured using dual-energy X-ray absorptiometry and calculated with the appendicular lean mass index. Health-related quality of life was measured using the EuroQol-5 dimension (EQ-5D) instrument. Univariate and multivariate survey logistic regression models were used to calculate odds ratios (OR) with 95% confidence intervals (95% CI) for the lowest quintile of the EQ-5D index. In total, 39.1% of participants were male and 60.9% were female. The weighted mean age was 75.6 years (95% CI; 75.3-75.9). Clinically significant weight loss is typically 5% of one's body weight; average, 2.8 kg (3.1 kg for men; 2.7 kg, women) for our participants. Compared with the normal reference group and after adjusting for potential confounders, the ORs for the lowest quintile of the EQ-5D indices were 1.39 (95% CI, 0.92-2.10), 2.56 (95% CI, 1.56-4.18), and 3.40 (95% CI, 2.05 to 5.63) for the low muscle mass, involuntary weight loss, involuntary weight loss with low muscle mass groups, respectively. Involuntary weight loss combined with low muscle mass was more closely associated with poor quality of life than involuntary weight loss alone in community-dwelling older adults. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

Different mechanisms may generate sustained hypertonic and rhythmic bursting muscle activity in idiopathic dystonia.

PubMed

Liu, Xuguang; Yianni, John; Wang, Shouyan; Bain, Peter G; Stein, John F; Aziz, Tipu Z

2006-03-01

Despite that deep brain stimulation (DBS) of the globus pallidus internus (GPi) is emerging as the favored intervention for patients with medically intractable dystonia, the pathophysiological mechanisms of dystonia are largely unclear. In eight patients with primary dystonia who were treated with bilateral chronic pallidal stimulation, we correlated symptom-related electromyogram (EMG) activity of the most affected muscles with the local field potentials (LFPs) recorded from the globus pallidus electrodes. In 5 dystonic patients with mobile involuntary movements, rhythmic EMG bursts in the contralateral muscles were coherent with the oscillations in the pallidal LFPs at the burst frequency. In contrast, no significant coherence was seen between EMG and LFPs either for the sustained activity separated out from the compound EMGs in those 5 cases, or in the EMGs in 3 other cases without mobile involuntary movements and rhythmic EMG bursts. In comparison with the resting condition, in both active and passive movements, significant modulation in the GPi LFPs was seen in the range of 8-16 Hz. The finding of significant coherence between GPi oscillations and rhythmic EMG bursts but not sustained tonic EMG activity suggests that the synchronized pallidal activity may be directly related to the rhythmic involuntary movements. In contrast, the sustained hypertonic muscle activity may be represented by less synchronized activity in the pallidum. Thus, the pallidum may play different roles in generating different components of the dystonic symptom complex.

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

Types of muscle tissue (image)

MedlinePlus

... appear striated, and are under involuntary control. Smooth muscle fibers are located in walls of hollow visceral organs, ... shaped, and are also under involuntary control. Skeletal muscle fibers occur in muscles which are attached to the ...

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. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Parkinson Disease: Treating Symptoms Unrelated to Muscle Movement

MedlinePlus

... Evidence-based Guideline for PATIENTS and their FAMILIES PARKINSON DISEASE: TREATING SYMPTOMS UNRELATED TO MUSCLE MOVEMENT This fact sheet may help you understand which therapies help Parkinson disease (PD) symptoms unrelated to muscle movement. Neurologists from ...

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.

Voluntary control of arm movement in athetotic patients

PubMed Central

Neilson, Peter D.

1974-01-01

Visual tracking tests have been employed to provide a quantitative description of voluntary control of arm movement in a group of patients suffering from athetoid cerebral palsy. Voluntary control was impaired in all patients in a characteristic manner. Maximum velocity and acceleration of arm movement were reduced to about 30-50% of their values in normal subjects and the time lag of the response to a visual stimulus was two or three times greater than in normals. Tracking transmission characteristics indicated a degree of underdamping which was not presnet in normal or spastic patients. This underdamping could be responsible for a low frequency (0·3-0·6 Hz) transient oscillation in elbow-angle movements associated with sudden voluntary movement. The maximum frequency at which patients could produce a coherent tracking response was only 50% of that in normal subjects and the relationship between the electromyogram and muscle contraction indicated that the mechanical load on the biceps muscle was abnormal, possibly due to increased stiffness of joint movement caused by involuntary activity in agonist and antagonist muscles acting across the joint. Images PMID:4362243

Effects of local and widespread muscle fatigue on movement timing.

PubMed

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

2014-12-01

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 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.

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

Influence of adequate pelvic floor muscle contraction on the movement of the coccyx during pelvic floor muscle training.

PubMed

Fujisaki, Akiko; Shigeta, Miwa; Shimoinaba, Misa; Yoshimura, Yasukuni

2018-04-01

[Purpose] Pelvic floor muscle training is a first-line therapy for female stress urinary incontinence. Previous studies have suggested that the coccyx tip moves ventrally and cranially during pelvic floor muscle contraction. The study aimed to elucidate the influence of adequate pelvic floor muscle contraction on coccyx movement. [Subjects and Methods] Sixty-three females (57 patients with stress urinary incontinence and additional 6 healthy volunteers) were enrolled. Using magnetic resonance imaging, coccyx movement was evaluated during pelvic floor muscle contraction and strain. An adequate contraction was defined as a contraction with good Oxford grading scale [≥3] and without inadequate muscle substitution patterns. [Results] Inadequate muscle substitution patterns were observed in 33 participants (52.4%). No significant difference was observed in the movement of the coccyx tip in the ventrodorsal direction between females with and without inadequate muscle substitution patterns. However, a significant increase in the movement of the coccyx tip in the cranial direction was detected in the group without inadequate muscle substitution patterns. Compared to participants with inadequate pelvic floor muscle contraction, those who had adequate pelvic floor muscle contraction exhibited significantly increased cranial movement of the coccyx. [Conclusion] Adequate pelvic floor muscle contraction can produce cranial movement of the coccyx tip.

Dr Samuel Johnson's movement disorder.

PubMed Central

Murray, T J

1979-01-01

Dr Samuel Johnson was noted by his friends to have almost constant tics and gesticulations, which startled those who met him for the first time. He also made noises and whistling sounds; he made repeated sounds and words and irregular or blowing respiratory noises. Further, he often carried out pronounced compulsive acts, such as touching posts, measuring his footsteps on leaving a room, and performing peculiar complex gestures and steps before crossing a threshold. His symptoms of (a) involuntary muscle jerking movements and complex motor acts, (b) involuntary vocalisation, and (c) compulsive actions constitute the symptom complex of Gilles de la Tourette syndrome (Tourette's syndrome), from which Johnson suffered most of his life. This syndrome is of increasing interest recently because it responds to haloperidol, and because there are new insights into a possible biochemical basis for the tics, vocalisations, and compulsions. PMID:380753

Restoration of hemodynamics in apnea struggle phase in association with involuntary breathing movements.

PubMed

Palada, Ivan; Bakovic, Darija; Valic, Zoran; Obad, Ante; Ivancev, Vladimir; Eterovic, Davor; Shoemaker, J Kevin; Dujic, Zeljko

2008-04-30

Involuntary breathing movements (IBM) that occur in the struggle phase of maximal apneas produce waves of negative intrathoracic pressure. This could augment the venous return, increasing thereby the cardiac output and gas exchange, and release the fresh blood from venous pools of spleen and liver. To test these hypotheses we used photoplethysmography and ultrasound for assessment of hemodynamics and spleen size before, during and after maximal dry apneas at large lung volume in 7 trained divers. During the easy-going phase cardiac output was reduced about 40%, due to reduction in stroke volume and in presence of reduced inferior vena cava venous return, while the spleen contracted for about 60 ml. Towards the end of the struggle phase, in presence of intense IBM, the spleen volume further decreased for about 70 ml, while cardiac output and caval flow almost renormalized. In conclusion, IBM coincide with splenic volume reduction and restoration of hemodynamics, likely facilitating the use of the last oxygen reserves before apnea cessation.

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

Directional tuning of human forearm muscle afferents during voluntary wrist movements

PubMed Central

Jones, Kelvin E; Wessberg, Johan; Vallbo, Åke B

2001-01-01

Single unit activity was recorded with the microneurography technique from sixteen spindle afferents and one Golgi tendon organ afferent originating from the forearm extensor muscles. Impulse rates were studied while subjects performed unobstructed aiming movements at the wrist in eight different directions 45 deg apart. In addition, similar imposed movements were performed while the subject was instructed to remain relaxed. Movement amplitudes were about 5 deg and the speed 10–30 deg s−1. Joint movements were translated to movements of a cursor on a monitor to provide visual feedback. Individual spindle afferents modulated their activity over a number of targets, i.e. were broadly tuned, during these aiming movements. The preferred direction for a spindle afferent was the same during both passive and active movements, indicating that the fusimotor effects associated with active contractions had little or no effect on the direction of tuning. The direction of tuning of individual spindle afferents could be predicted from the biomechanically inferred length changes of the parent muscle. Thus spindle afferents responded as stretch receptors, i.e. impulse rates increased with lengthening and decreased with shortening, in active as well as passive movements. Spindles from muscles, which continuously counteracted gravity exhibited a stretch response and directional tuning during the phase of movement alone whereas their position sensitivity was poor. In contrast, spindle afferents from the muscles that had no or minimal antigravity role were directionally tuned during both the dynamic and the static phase of the aiming task and their position sensitivity was substantially higher. In spite of the limited data base from three extensor muscles it could be demonstrated that wrist joint position was remarkably well encoded in the ensemble muscle spindle data. In some cases the ensemble muscle spindle data encoded the instantaneous trajectory of movement as well. PMID

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.

The Effect of Paired Muscle Stimulation on Preparation for Movement.

PubMed

Brownjohn, Philip W; Blakemore, Rebekah L; Fox, Jonathan A; Shemmell, Jonathan

2018-06-07

Paired muscle stimulation is used clinically to facilitate the performance of motor tasks for individuals with motor dysfunction. However, the optimal temporal relationship between stimuli for enhancing movement remains unknown. We hypothesized that synchronous, muscle stimulation would increase the extent to which stimulated muscles are concurrently prepared for movement. We validated a measure of muscle-specific changes in corticomotor excitability prior to movement. We used this measure to examine the preparation of the first dorsal interosseous (FDI), abductor digiti minimi (ADM), abductor pollicis brevis (APB) muscles prior to voluntary muscle contractions before and after paired muscle stimulation at four interstimulus intervals (0, 5, 10, and 75 ms). Paired muscle stimulation increased premovement excitability in the stimulated FDI, but not in the ADM muscle. Interstimulus interval was not a significant factor in determining efficacy of the protocol. Paired stimulation, therefore, did not result in a functional association being formed between the stimulated muscles. Somatosensory potentials evoked by the muscle stimuli were small compared to those commonly elicited by stimulation of peripheral nerves, suggesting that the lack of functional association formation between muscles may be due to the small magnitude of afferent volleys from the stimulated muscles, particularly the ADM, reaching the cortex.

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.

Increased task-uncorrelated muscle activity in childhood dystonia.

PubMed

Lunardini, Francesca; Maggioni, Serena; Casellato, Claudia; Bertucco, Matteo; Pedrocchi, Alessandra L G; Sanger, Terence D

2015-06-12

Even if movement abnormalities in dystonia are obvious on observation-based examinations, objective measures to characterize dystonia and to gain insights into its pathophysiology are still strongly needed. We hypothesize that motor abnormalities in childhood dystonia are partially due to the inability to suppress involuntary variable muscle activity irrelevant to the achievement of the desired motor task, resulting in the superposition of unwanted motion components on the desired movement. However, it is difficult to separate and quantify appropriate and inappropriate motor signals combined in the same muscle, especially during movement. We devise an innovative and practical method to objectively measure movement abnormalities during the performance of a continuous figure-eight writing task in 7 children with dystonia and 9 age-matched healthy controls. During the execution of a continuous writing task, muscle contractions should occur at frequencies that match the frequencies of the writing outcome. We compare the power spectra of kinematic trajectories and electromyographic signals of 8 upper limb muscles to separate muscle activity with the same frequency content of the figure-eight movement (task-correlated) from activity occurring at frequencies extraneous to the task (task-uncorrelated). Children with dystonia present a greater magnitude of task-uncorrelated muscle components. The motor performance achieved by children with dystonia is characterized by an overall lower quality, with high spatial and temporal variability and an altered trade-off between speed and accuracy. Findings are consistent with the hypothesis that, in childhood dystonia, the ability to appropriately suppress variable and uncorrelated elements of movement is impaired. Here we present a proof-of-concept of a promising tool to characterize the phenomenology of movement disorders and to inform the design of neurorehabilitation therapies.

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.

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

Trunk muscle activity increases with unstable squat movements.

PubMed

Anderson, Kenneth; Behm, David G

2005-02-01

The objective of this study was to determine differences in electromyographic (EMG) activity of the soleus (SOL), vastus lateralis (VL), biceps femoris (BF), abdominal stabilizers (AS), upper lumbar erector spinae (ULES), and lumbo-sacral erector spinae (LSES) muscles while performing squats of varied stability and resistance. Stability was altered by doing the squat movement on a Smith machine, a free squat, and while standing on two balance discs. Fourteen male subjects performed the movements. Activities of the SOL, AS, ULES, and LSES were highest during the unstable squat and lowest with the Smith machine protocol (p < 0.05). Increased EMG activity of these muscles may be attributed to their postural and stabilization role. Furthermore, EMG activity was higher during concentric contractions compared to eccentric contractions. Performing squats on unstable surfaces may permit a training adaptation of the trunk muscles responsible for supporting the spinal column (i.e., erector spinae) as well as the muscles most responsible for maintaining posture (i.e., SOL).

Charge movements and transverse tubular ultrastructure in organ cultured skeletal muscle.

PubMed

Cullen, M J; Hollingworth, S; Marshall, M W; Robson, E

1990-04-01

A study was made of charge movements and the transverse tubular systems in rat EDL and soleus muscle fibres maintained for up to five days in organ culture. In the cultured EDL muscle the maximum amount of charge moved was about one third of that in innervated muscle. Charge movements in innervated soleus fibres are small, less than 10 nC/microF, and difficult to resolve. They remain small following organ culturing. The ultrastructural study examined the concentration of junctional feet because of their proposed key role in excitation-contraction coupling. The general architecture of the triads and the spacing of the feet in both muscle types was largely unchanged by culturing. In cultured EDL muscles the small changes in feet concentration did not parallel the large fall in charge movement. The results reported here support a previous conclusion that, in mammalian muscle, there is not a simple relation between charge and feet. The stimulation of cultured soleus muscles with a fast twitch pattern of electrical activity produced no observable changes in morphology.

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.

[A case of respiratory dyskinesia due to clebopride malate].

PubMed

Kawasaki, H; Yamamoto, M; Okayasu, H; Wakayama, Y

1991-08-01

Clebopride malate is therapeutically used for the treatment of peptic ulcer. This drug has potent antidopaminergic activity that causes acute dystonic reaction, parkinsonism and tardive dyskinesia as adverse effects. Here, we have reported an 86-year-old man who developed abnormal involuntary movement of respiratory muscles and lower limb muscles after this drug had been given for four months. This involuntary movement appeared spontaneously at resting state and disappeared during sleep. Surface EMG demonstrated a synchronous grouping discharge in m. orbicularis oris, m. sternocleidomastoideus and m. interstales which synchronized with diaphragmatic movement on cinefluorography. Involuntary movement of the lower limbs was synchronous bilaterally and had little relationship with diaphragmatic movement. This involuntary movement was irregular not only in rhythm but also in duration. According to this irregular nature, we diagnosed this involuntary movement as respiratory dyskinesia with limb dyskinesia that belongs to tardive dyskinesia. After cessation of clebopride malate limb dyskinesia disappeared rapidly and respiratory dyskinesia markedly decreased. We emphasize that respiratory dyskinesia should be differentiated from psychogenic hyperventilation as easily misdiagnosed on initial examination.

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.

Ankle joint movements are encoded by both cutaneous and muscle afferents in humans.

PubMed

Aimonetti, Jean-Marc; Roll, Jean-Pierre; Hospod, Valérie; Ribot-Ciscar, Edith

2012-08-01

We analyzed the cutaneous encoding of two-dimensional movements by investigating the coding of movement velocity for differently oriented straight-line movements and the coding of complex trajectories describing cursive letters. The cutaneous feedback was then compared with that of the underlying muscle afferents previously recorded during the same "writing-like" movements. The unitary activity of 43 type II cutaneous afferents was recorded in the common peroneal nerve in healthy subjects during imposed ankle movements. These movements consisted first of ramp-and-hold movements imposed at two different and close velocities in seven directions and secondly of "writing-like" movements. In both cases, the responses were analyzed using the neuronal population vector model. The results show that movement velocity encoding depended on the direction of the ongoing movement. Discriminating between two velocities therefore involved processing the activity of afferent populations located in the various skin areas surrounding the moving joint, as shown by the statistically significant difference observed in the amplitude of the sum vectors. Secondly, "writing-like" movements induced cutaneous neuronal patterns of activity, which were reproducible and specific to each trajectory. Lastly, the "cutaneous neuronal trajectories," built by adding the sum vectors tip-to-tail, nearly matched both the movement trajectories and the "muscle neuronal trajectories," built from previously recorded muscle afferents. It was concluded that type II cutaneous and the underlying muscle afferents show similar encoding properties of two-dimensional movement parameters. This similarity is discussed in relation to a central gating process that would for instance increase the gain of cutaneous inputs when muscle information is altered by the fusimotor drive.

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

Biomechanical behavior of muscle-tendon complex during dynamic human movements.

PubMed

Fukashiro, Senshi; Hay, Dean C; Nagano, Akinori

2006-05-01

This paper reviews the research findings regarding the force and length changes of the muscle-tendon complex during dynamic human movements, especially those using ultrasonography and computer simulation. The use of ultrasonography demonstrated that the tendinous structures of the muscle-tendon complex are compliant enough to influence the biomechanical behavior (length change, shortening velocity, and so on) of fascicles substantially. It was discussed that the fascicles are a force generator rather than a work generator; the tendinous structures function not only as an energy re-distributor but also as a power amplifier, and the interaction between fascicles and tendinous structures is essential for generating higher joint power outputs during the late pushoff phase in human vertical jumping. This phenomenon could be explained based on the force-length/velocity relationships of each element (contractile and series elastic elements) in the muscle-tendon complex during movements. Through computer simulation using a Hill-type muscle-tendon complex model, the benefit of making a countermovement was examined in relation to the compliance of the muscle-tendon complex and the length ratio between the contractile and series elastic elements. Also, the integral roles of the series elastic element were simulated in a cyclic human heel-raise exercise. It was suggested that the storage and reutilization of elastic energy by the tendinous structures play an important role in enhancing work output and movement efficiency in many sorts of human movements.

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

PubMed

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

2016-11-01

[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.

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.

Transversus abdominis is part of a global not local muscle synergy during arm movement.

PubMed

Morris, S L; Lay, B; Allison, G T

2013-10-01

The trunk muscle transversus abdominis (TrA) is thought to be controlled independently of the global trunk muscles. Methodological issues in the 1990s research such as unilateral electromyography and a limited range of arm movements justify a re-examination of this theory. The hypothesis tested is that TrA bilateral co-contraction is a typical muscle synergy during arm movement. The activity of 6 pairs of trunk and lower limb muscles was recorded using bilateral electromyography during anticipatory postural adjustments (APAs) associated with the arm movements. The integrated APA electromyographical signals were analyzed for muscle synergy using Principle Component Analysis. TrA does not typically bilaterally co-contract during arm movements (1 out of 6 participants did). APA muscle activity of all muscles during asymmetrical arm movements typically reflected a direction specific diagonal pattern incorporating a twisting motion to transfer energy from the ground up. This finding is not consistent with the hypothesis that TrA plays a unique role providing bilateral, feedforward, multidirectional stiffening of the spine. This has significant implications to the theories underlying the role of TrA in back pain and in the training of isolated bilateral co-contraction of TrA in the prophylaxis of back pain. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Myomodulation with Injectable Fillers: An Innovative Approach to Addressing Facial Muscle Movement.

PubMed

de Maio, Maurício

2018-06-01

Consideration of facial muscle dynamics is underappreciated among clinicians who provide injectable filler treatment. Injectable fillers are customarily used to fill static wrinkles, folds, and localized areas of volume loss, whereas neuromodulators are used to address excessive muscle movement. However, a more comprehensive understanding of the role of muscle function in facial appearance, taking into account biomechanical concepts such as the balance of activity among synergistic and antagonistic muscle groups, is critical to restoring facial appearance to that of a typical youthful individual with facial esthetic treatments. Failure to fully understand the effects of loss of support (due to aging or congenital structural deficiency) on muscle stability and interaction can result in inadequate or inappropriate treatment, producing an unnatural appearance. This article outlines these concepts to provide an innovative framework for an understanding of the role of muscle movement on facial appearance and presents cases that illustrate how modulation of muscle movement with injectable fillers can address structural deficiencies, rebalance abnormal muscle activity, and restore facial appearance. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Local subcutaneous and muscle pain impairs detection of passive movements at the human thumb

PubMed Central

Weerakkody, N S; Blouin, J S; Taylor, J L; Gandevia, S C

2008-01-01

Activity in both muscle spindle endings and cutaneous stretch receptors contributes to the sensation of joint movement. The present experiments assessed whether muscle pain and subcutaneous pain distort proprioception in humans. The ability to detect the direction of passive movements at the interphalangeal joint of the thumb was measured when pain was induced experimentally in four sites: the flexor pollicis longus (FPL), the subcutaneous tissue overlying this muscle, the flexor carpi radialis (FCR) muscle and the subcutaneous tissue distal to the metacarpophalangeal joint of thumb. Tests were conducted when pain was at a similar subjective intensity. There was no significant difference in the ability to detect flexion or extension under any painful or non-painful condition. The detection of movement was significantly impaired when pain was induced in the FPL muscle, but pain in the FCR, a nearby muscle that does not act on the thumb, had no effect. Subcutaneous pain also significantly impaired movement detection when initiated in skin overlying the thumb, but not in skin overlying the FPL muscle in the forearm. These findings suggest that while both muscle and skin pain can disturb the detection of the direction of movement, the impairment is site-specific and involves regions and tissues that have a proprioceptive role at the joint. Also, pain induced in FPL did not significantly increase the perceived size of the thumb. Proprioceptive mechanisms signalling perceived body size are less disturbed by a relevant muscle nociceptive input than those subserving movement detection. The results highlight the complex relationship between nociceptive inputs and their influence on proprioception and motor control. PMID:18467366

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.

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

PubMed

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

2017-03-08

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.

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.

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.

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.

Charge movement in a fast twitch skeletal muscle from rat.

PubMed

Simon, B J; Beam, K G

1983-02-01

Voltage-dependent charge movement in the rat omohyoid muscle was investigated using the three microelectrode voltage clamp technique. The charge that moved during a depolarization from the holding potential (-90 mV) to the test potential, V, increased with increasing V, saturating around 0 mV. The charge vs. voltage relationship was well fitted by Q = Q(max)/{1 + exp[-(V - V)/k]}, with Q(max) = 28.5 nC/muF, V = -34.2 mV, and k = 8.7 mV. Repolarization of the fiber from the test potential back to the holding potential caused an equal but opposite amount of charge to move. The kinetics of ON charge movement could be well described by a model developed for frog muscle by Horowicz and Schneider (1981b), which suggests that rat and frog charge movements are similar. This model failed to describe the kinetics of OFF charge movement for steps in potential from 0 mV to test potentials of -10 to -90 mV. OFF-charge movement rose to a peak more slowly and decayed more slowly than predicted by the theory.

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.

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

Understanding movement control in infants through the analysis of limb intersegmental dynamics.

PubMed

Schneider, K; Zernicke, R F; Ulrich, B D; Jensen, J L; Thelen, E

1990-12-01

One important component in the understanding of the control of limb movements is the way in which the central nervous system accounts for joint forces and torques that may be generated not only by muscle actions but by gravity and by passive reactions related to the movements of limb segments. In this study, we asked how the neuromotor system of young infants controls a range of active and passive forces to produce a stereotypic, nonintentional movement. We specifically analyzed limb intersegmental dynamics in spontaneous, cyclic leg movements (kicking) of varying intensity in supine 3-month-old human infants. Using inverse dynamics, we calculated the contributions of active (muscular) and passive (motion-dependent and gravitational) torque components at the hip, knee, and ankle joints from three-dimensional limb kinematics. To calculate joint torques, accurate estimates were needed of the limb's anthropometric parameters, which we determined using a model of the human body. Our analysis of limb intersegmental dynamics explicitly quantified the complex interplay of active and passive forces producing the simple, involuntary kicking movements commonly seen in 3-month-old infants. our results revealed that in nonvigorous kicks, hip joint reversal was the result of an extensor torque due to gravity, opposed by the combined flexor effect of the muscle torque and the total motion-dependent torque. The total motion-dependent torque increased as a hip flexor torque in more vigorous kicks; an extensor muscle torque was necessary to counteract the flexor influences of the total motion-dependent torque and, in the case of large ranges of motion, a flexor gravity torque as well. Thus, with changing passive torque influences due to motions of the linked segments, the muscle torques were adjusted to produce a net torque to reverse the kicking motion. As a consequence, despite considerable heterogeneity in the intensity, range of motion, coordination, and movement context of

Load emphasizes muscle effort minimization during selection of arm movement direction

PubMed Central

2012-01-01

Background Directional preferences during center-out horizontal shoulder-elbow movements were previously established for both the dominant and non-dominant arm with the use of a free-stroke drawing task that required random selection of movement directions. While the preferred directions were mirror-symmetrical in both arms, they were attributed to a tendency specific for the dominant arm to simplify control of interaction torque by actively accelerating one joint and producing largely passive motion at the other joint. No conclusive evidence has been obtained in support of muscle effort minimization as a contributing factor to the directional preferences. Here, we tested whether distal load changes directional preferences, making the influence of muscle effort minimization on the selection of movement direction more apparent. Methods The free-stroke drawing task was performed by the dominant and non-dominant arm with no load and with 0.454 kg load at the wrist. Motion of each arm was limited to rotation of the shoulder and elbow in the horizontal plane. Directional histograms of strokes produced by the fingertip were calculated to assess directional preferences in each arm and load condition. Possible causes for directional preferences were further investigated by studying optimization across directions of a number of cost functions. Results Preferences in both arms to move in the diagonal directions were revealed. The previously suggested tendency to actively accelerate one joint and produce passive motion at the other joint was supported in both arms and load conditions. However, the load increased the tendency to produce strokes in the transverse diagonal directions (perpendicular to the forearm orientation) in both arms. Increases in required muscle effort caused by the load suggested that the higher frequency of movements in the transverse directions represented increased influence of muscle effort minimization on the selection of movement direction. This

Disorders of Upper Limb Movements in Ataxia-Telangiectasia.

PubMed

Shaikh, Aasef G; Zee, David S; Mandir, Allen S; Lederman, Howard M; Crawford, Thomas O

2013-01-01

Ataxia-telangiectasia is known for cerebellar degeneration, but clinical descriptions of abnormal tone, posture, and movements suggest involvement of the network between cerebellum and basal ganglia. We quantitatively assessed the nature of upper-limb movement disorders in ataxia-telangiectasia. We used a three-axis accelerometer to assess the natural history and severity of abnormal upper-limb movements in 80 ataxia-telangiectasia and 19 healthy subjects. Recordings were made during goal-directed movements of upper limb (kinetic task), while arms were outstretched (postural task), and at rest. Almost all ataxia-telangiectasia subjects (79/80) had abnormal involuntary movements, such as rhythmic oscillations (tremor), slow drifts (dystonia or athetosis), and isolated rapid movements (dystonic jerks or myoclonus). All patients with involuntary movements had both kinetic and postural tremor, while 48 (61%) also had resting tremor. The tremor was present in transient episodes lasting several seconds during two-minute recording sessions of all three conditions. Percent time during which episodic tremor was present was greater for postural and kinetic tasks compared to rest. Resting tremor had higher frequency but smaller amplitude than postural and kinetic tremor. Rapid non-rhythmic movements were minimal during rest, but were triggered during sustained arm postures and goal directed arm movements suggesting they are best considered a form of dystonic jerks or action myoclonus. Advancing age did not correlate with the severity of involuntary limb movements. Abnormal upper-limb movements in ataxia-telangiectasia feature classic cerebellar impairment, but also suggest involvement of the network between the cerebellum and basal ganglia.

Disorders of Upper Limb Movements in Ataxia-Telangiectasia

PubMed Central

Shaikh, Aasef G.; Zee, David S.; Mandir, Allen S.; Lederman, Howard M.; Crawford, Thomas O.

2013-01-01

Ataxia-telangiectasia is known for cerebellar degeneration, but clinical descriptions of abnormal tone, posture, and movements suggest involvement of the network between cerebellum and basal ganglia. We quantitatively assessed the nature of upper-limb movement disorders in ataxia-telangiectasia. We used a three-axis accelerometer to assess the natural history and severity of abnormal upper-limb movements in 80 ataxia-telangiectasia and 19 healthy subjects. Recordings were made during goal-directed movements of upper limb (kinetic task), while arms were outstretched (postural task), and at rest. Almost all ataxia-telangiectasia subjects (79/80) had abnormal involuntary movements, such as rhythmic oscillations (tremor), slow drifts (dystonia or athetosis), and isolated rapid movements (dystonic jerks or myoclonus). All patients with involuntary movements had both kinetic and postural tremor, while 48 (61%) also had resting tremor. The tremor was present in transient episodes lasting several seconds during two-minute recording sessions of all three conditions. Percent time during which episodic tremor was present was greater for postural and kinetic tasks compared to rest. Resting tremor had higher frequency but smaller amplitude than postural and kinetic tremor. Rapid non-rhythmic movements were minimal during rest, but were triggered during sustained arm postures and goal directed arm movements suggesting they are best considered a form of dystonic jerks or action myoclonus. Advancing age did not correlate with the severity of involuntary limb movements. Abnormal upper-limb movements in ataxia-telangiectasia feature classic cerebellar impairment, but also suggest involvement of the network between the cerebellum and basal ganglia. PMID:23826191

Proprioceptive guidance of human voluntary wrist movements studied using muscle vibration.

PubMed Central

Cody, F W; Schwartz, M P; Smit, G P

1990-01-01

1. The alterations in voluntary wrist extension and flexion movement trajectories induced by application of vibration to the tendon of flexor carpi radialis throughout the course of the movement, together with the associated EMG patterns, have been studied in normal human subjects. Both extension and flexion movements were routinely of a target amplitude of 30 deg and made against a torque load of 0.32 N m. Flexor tendon vibration consistently produced undershooting of voluntary extension movements. In contrast, voluntary flexion movements were relatively unaffected. 2. The degree of vibration-induced undershooting of 1 s voluntary extension movements was graded according to the amplitude (0.75, 1.0 and 1.5 mm) of flexor tendon vibration. 3. As flexor vibration was initiated progressively later (at greater angular thresholds) during the course of 1 s voluntary extension movements, and the period of vibration was proportionately reduced, so the degree of vibration-induced undershooting showed a corresponding decline. 4. Varying the torque loads (0.32, 0.65 and 0.97 N m) against which 1 s extension movements were made, and thereby the strength of voluntary extensor contraction, produced no systematic changes in the degree of flexor vibration-induced undershooting. 5. Analysis of EMG patterns recorded from wrist flexor and extensor muscles indicated that vibration-induced undershooting of extension movements resulted largely from a reduction in activity in the prime-mover rather than increased antagonist activity. The earliest reductions in extensor EMG commenced some 40 ms after the onset of vibration, i.e. well before voluntary reaction time; these initial responses were considered to be 'automatic' in nature. 6. These results support the view that the central nervous system utilizes proprioceptive information in the continuous regulation of moderately slow voluntary wrist movements. Proprioceptive sensory input from the passively lengthening antagonist muscle

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.

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

PubMed Central

Ge, Weiqing; Cao, Dong-Yuan; Long, Cynthia R.

2011-01-01

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 L6 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 L6 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. PMID:21960662

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.

A comparative study of charge movement in rat and frog skeletal muscle fibres.

PubMed

Hollingworth, S; Marshall, M W

1981-12-01

1. The middle of the fibre voltage--clamp technique (Adrian & Marshall, 1977), modified where necessary for electrically short muscle fibres, has been used to measure non-linear charge movements in mammalian fast twitch (rat extensor digitorum longus), mammalian slow twitch (rat soleus) and frog (sartorius) muscles. 2. The maximum amount of charge moved in mammalian fast twitch muscle at 2 degrees C in hypertonic solution, was 3--5 times greater than in slow twitch muscle. The voltage distribution of fast twitch charge was 10--15 mV more positive when compared to slow twitch. 3. In both mammalian muscle types hypertonic Ringer solution negatively shifted the voltage distribution of charge some 6 mV. The steepness of charge moved around mechanical threshold was unaffected by hypertonicity. 4. The amount of charge in frog sartorius fibres at 2 degrees C in hypertonic solution was about half of that in rat fast twitch muscle; the voltage distribution of the frog charge was similar to rat soleus muscle. 5. Warming between 2 and 15 degrees C had no effect on either the amount of steady-state distribution of charge in mammalian or frog muscles. 6. At 2 degrees C, the kinetics of charge movement in fast and slow twitch mammalian muscles were similar and 2--3 times faster than frog muscle at the same temperature. In fast and slow mammalian fibres at 2 degrees C similar times were taken to shift the same fractions of the total amount of charge. The Q10 of charge movement kinetics was between 1.2 and 2.0 in the three muscles studied.

Muscle fatigue effects can be anticipated to reproduce a movement kinematics learned without fatigue.

PubMed

Monjo, Florian; Forestier, Nicolas

2016-12-17

Muscle fatigue modifies the gain between motor command magnitude and the mechanical muscular response. In other words, post-fatigue, central drives to the muscles must increase to maintain a particular submaximum mechanical output. In this study, we tested the hypothesis that this modified gain can be predicted by the central nervous system (CNS) during discrete ballistic movements. In two separate experiments, subjects were required to perform shoulder flexions in standing and sitting positions at submaximum target peak accelerations. They were assisted with visual feedback informing them on their performance after each trial. Shoulder flexions were performed before and after fatiguing protocols of the focal muscles. Acceleration signals, focal and postural muscle electromyograms (EMGs) were recorded. The results demonstrated that participants were able to reach with precision the target acceleration during the first movements post-fatigue at the cost of significant increase in focal motor command magnitude. Decreased variance of peak accelerations associated with increased focal command variability was observed post-fatigue. During the standing experiment, postural muscle EMGs revealed that anticipatory postural adjustments (APAs) scaled to focal movement acceleration post-fatigue. All these results support that fatigue effects are taken into account during movement planning. Indeed, given that no feedback could enable participants to adjust acceleration during movement, this capacity to anticipate fatigue effects is the exclusive result of feedforward processes. To account for this prediction capacity, we discuss the role of fatigue-related modifications in sensory inputs from the working muscles. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

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

PubMed Central

Darby, John; 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. PMID:22033532

Ionic currents and charge movements in organ-cultured rat skeletal muscle.

PubMed

Hollingworth, S; Marshall, M W; Robson, E

1984-12-01

The middle of the fibre voltage-clamp technique was used to measure ionic currents and non-linear charge movements in intact, organ-cultured (in vitro denervated) mammalian fast-twitch (rat extensor digitorum longus) muscle fibres. Muscle fibres organ cultured for 4 days can be used as electrophysiological and morphological models for muscles in vivo denervated for the same length of time. Sodium currents in organ-cultured muscle fibres are similar to innervated fibres except that in the temperature range 0-20 degrees C (a) in the steady state, the voltage distribution of inactivation in cultured fibres is shifted negatively some 20 mV; (b) at the same temperature and membrane potential, the time constant of inactivation in cultured fibres is about twice that of innervated fibres. Potassium currents in innervated and cultured fibres at 15 degrees C can be fitted with the Hodgkin-Huxley n variable raised to the second power. Despite the large range we would estimate that the maximum value of the steady-state potassium conductance of cultured fibres is about one-half that of innervated fibres. The estimated maximum amount of charge moved in cultured fibre is about one-third that in innervated fibres. Compared to innervated fibres, culturing doubles the kinetics of the decay phase of charge movement. The possibility of a negative shift of the voltage distribution of charge movements in cultured fibres is discussed.

Does induced masseter muscle pain affect integrated jaw-neck movements similarly in men and women?

PubMed

Wiesinger, Birgitta; Häggman-Henrikson, Birgitta; Hellström, Fredrik; Englund, Erling; Wänman, Anders

2016-12-01

Normal jaw opening-closing involves simultaneous jaw and head-neck movements. We previously showed that, in men, integrated jaw-neck movements during jaw function are altered by induced masseter muscle pain. The aim of this study was to investigate possible sex-related differences in integrated jaw-neck movements following experimental masseter muscle pain. We evaluated head-neck and jaw movements in 22 healthy women and 16 healthy men in a jaw opening-closing task. The participants performed one control trial and one trial with masseter muscle pain induced by injection of hypertonic saline. Jaw and head movements were registered using a three-dimensional optoelectronic recording system. There were no significant sex-related differences in jaw and head movement amplitudes. Head movement amplitudes were significantly greater in the pain trials for both men and women. The proportional involvement of the neck motor system during jaw movements increased in pain trials for 13 of 16 men and for 18 of 22 women. Thus, acute pain may alter integrated jaw-neck movements, although, given the similarities between men and women, this interaction between acute pain and motor behaviour does not explain sex differences in musculoskeletal pain in the jaw and neck regions. © 2016 Eur J Oral Sci.

Movement measurement of isolated skeletal muscle using imaging microscopy

NASA Astrophysics Data System (ADS)

Elias, David; Zepeda, Hugo; Leija, Lorenzo S.; Sossa, Humberto; de la Rosa, Jose I.

1997-05-01

An imaging-microscopy methodology to measure contraction movement in chemically stimulated crustacean skeletal muscle, whose movement speed is about 0.02 mm/s is presented. For this, a CCD camera coupled to a microscope and a high speed digital image acquisition system, allowing us to capture 960 images per second are used. The images are digitally processed in a PC and displayed in a video monitor. A maximal field of 0.198 X 0.198 mm2 and a spatial resolution of 3.5 micrometers are obtained.

The effect of arm weight support on upper limb muscle synergies during reaching movements

PubMed Central

2014-01-01

Background Compensating for the effect of gravity by providing arm-weight support (WS) is a technique often utilized in the rehabilitation of patients with neurological conditions such as stroke to facilitate the performance of arm movements during therapy. Although it has been shown that, in healthy subjects as well as in stroke survivors, the use of arm WS during the performance of reaching movements leads to a general reduction, as expected, in the level of activation of upper limb muscles, the effects of different levels of WS on the characteristics of the kinematics of motion and of the activity of upper limb muscles have not been thoroughly investigated before. Methods In this study, we systematically assessed the characteristics of the kinematics of motion and of the activity of 14 upper limb muscles in a group of 9 healthy subjects who performed 3-D arm reaching movements while provided with different levels of arm WS. We studied the hand trajectory and the trunk, shoulder, and elbow joint angular displacement trajectories for different levels of arm WS. Besides, we analyzed the amplitude of the surface electromyographic (EMG) data collected from upper limb muscles and investigated patterns of coordination via the analysis of muscle synergies. Results The characteristics of the kinematics of motion varied across WS conditions but did not show distinct trends with the level of arm WS. The level of activation of upper limb muscles generally decreased, as expected, with the increase in arm WS. The same eight muscle synergies were identified in all WS conditions. Their level of activation depended on the provided level of arm WS. Conclusions The analysis of muscle synergies allowed us to identify a modular organization underlying the generation of arm reaching movements that appears to be invariant to the level of arm WS. The results of this study provide a normative dataset for the assessment of the effects of the level of arm WS on muscle synergies in stroke

A startling acoustic stimulus facilitates voluntary lower extremity movements and automatic postural responses in people with chronic stroke.

PubMed

Coppens, Milou J M; Roelofs, Jolanda M B; Donkers, Nicole A J; Nonnekes, Jorik; Geurts, Alexander C H; Weerdesteyn, Vivian

2018-05-14

A startling acoustic stimulus (SAS) involuntary releases prepared movements at accelerated latencies, known as the StartReact effect. Previous work has demonstrated intact StartReact in paretic upper extremity movements in people after stroke, suggesting preserved motor preparation. The question remains whether motor preparation of lower extremity movements is also unaffected after stroke. Here, we investigated StartReact effects on ballistic lower extremity movements and on automatic postural responses (APRs) following perturbations to standing balance. These APRs are particularly interesting as they are critical to prevent a fall following balance perturbations, but show substantial delays and poor muscle coordination after stroke. Twelve chronic stroke patients and 12 healthy controls performed voluntary ankle dorsiflexion movements in response to a visual stimulus, and responded to backward balance perturbations evoking APRs. Twenty-five percent of all trials contained a SAS (120 dB) simultaneously with the visual stimulus or balance perturbation. As expected, in the absence of a SAS muscle and movement onset latencies at the paretic side were delayed compared to the non-paretic leg and to controls. The SAS accelerated ankle dorsiflexion onsets in both the legs of the stroke subjects and in controls. Following perturbations, the SAS accelerated bilateral APR onsets not only in controls, but for the first time, we also demonstrated this effect in people after stroke. Moreover, APR inter- and intra-limb muscle coordination was rather weak in our stroke subjects, but substantially improved when the SAS was applied. These findings show preserved movement preparation, suggesting that there is residual (subcortical) capacity for motor recovery.

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.

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…

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.

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. 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 to...

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... PROPERTY REAL ESTATE HANDBOOK Acquisition Involuntary Acquisition by the United States § 644.102 Examples... property, as prescribed by Pub. L. 91-646. Examples of involuntary acquisition are: (a) Damage to real...

The neural basis of involuntary episodic memories.

PubMed

Hall, Shana A; Rubin, David C; Miles, Amanda; Davis, Simon W; Wing, Erik A; Cabeza, Roberto; Berntsen, Dorthe

2014-10-01

Voluntary episodic memories require an intentional memory search, whereas involuntary episodic memories come to mind spontaneously without conscious effort. Cognitive neuroscience has largely focused on voluntary memory, leaving the neural mechanisms of involuntary memory largely unknown. We hypothesized that, because the main difference between voluntary and involuntary memory is the controlled retrieval processes required by the former, there would be greater frontal activity for voluntary than involuntary memories. Conversely, we predicted that other components of the episodic retrieval network would be similarly engaged in the two types of memory. During encoding, all participants heard sounds, half paired with pictures of complex scenes and half presented alone. During retrieval, paired and unpaired sounds were presented, panned to the left or to the right. Participants in the involuntary group were instructed to indicate the spatial location of the sound, whereas participants in the voluntary group were asked to additionally recall the pictures that had been paired with the sounds. All participants reported the incidence of their memories in a postscan session. Consistent with our predictions, voluntary memories elicited greater activity in dorsal frontal regions than involuntary memories, whereas other components of the retrieval network, including medial-temporal, ventral occipitotemporal, and ventral parietal regions were similarly engaged by both types of memories. These results clarify the distinct role of dorsal frontal and ventral occipitotemporal regions in predicting strategic retrieval and recalled information, respectively, and suggest that, although there are neural differences in retrieval, involuntary memories share neural components with established voluntary memory systems.

The Neural Basis of Involuntary Episodic Memories

PubMed Central

Hall, Shana A.; Rubin, David C.; Miles, Amanda; Davis, Simon W.; Wing, Erik A.; Cabeza, Roberto; Berntsen, Dorthe

2014-01-01

Voluntary episodic memories require an intentional memory search, whereas involuntary episodic memories come to mind spontaneously without conscious effort. Cognitive neuroscience has largely focused on voluntary memory, leaving the neural mechanisms of involuntary memory largely unknown. We hypothesized that because the main difference between voluntary and involuntary memory is the controlled retrieval processes required by the former, there would be greater frontal activity for voluntary than involuntary memories. Conversely, we predicted that other components of the episodic retrieval network would be similarly engaged in the two types of memory. During encoding, all participants heard sounds, half paired with pictures of complex scenes and half presented alone. During retrieval, paired and unpaired sounds were presented panned to the left or to the right. Participants in the involuntary group were instructed to indicate the spatial location of the sound, whereas participants in the voluntary group were asked to additionally recall the pictures that had been paired with the sounds. All participants reported the incidence of their memories in a post-scan session. Consistent with our predictions, voluntary memories elicited greater activity in dorsal frontal regions than involuntary memories, whereas other components of the retrieval network, including medial temporal, ventral occipitotemporal, and ventral parietal regions were similarly engaged by both types of memories. These results clarify the distinct role of dorsal frontal and ventral occipitotemporal regions in predicting strategic retrieval and recalled information, respectively, and suggest that while there are neural differences in retrieval, involuntary memories share neural components with established voluntary memory systems. PMID:24702453

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

[EMG activities of the head, neck and upper trunk muscles with mandibular movements in healthy adults and mandibular asymmetry patients].

PubMed

Jiang, Ting; Zhang, Zhenkang; Yang, Zhaohui; Yi, Biao; Feng, Hailan; Wang, Xing

2002-03-25

To study the activities of head, neck and upper trunk muscles during mandibular movements in healthy adults and mandibular asymmetry patients. Electromyographic integrogram was used to record and analyze the electromyographic activities of the anterior temporal (Ta), posterior temporal (Tp), sternocleidomastoid (SCM), and trapezius (TRAP) muscles in rest position and during mandibular movement among 10 normal adults and 10 mandibular asymmetry patients. All the four muscles showed constant electromyographic activities when the mandible was in the rest position. The activities of Ta, Tp, and SCM muscles increased with protrusion of mandible, mouth opening, tapping, maximum clenching, and chewing. The activities of Ta and Tp muscles of the patients were 1.7 times greater than that of the normal adults during mandibular movement without occlusion, and were weaker by 50% during mandibular movement with occlusion. The difference between electromyographic activities during mandibular movement and in rest position was less among patients than among normal adults. The TRAP muscle of the patients showed constant electromyographic activities with the activity volume nearly 1.8 times that of the normal adults. The difference between the muscle and its namesake at the opposite side was greater among the patients (21%) than among the normal adults (8%). All the four muscles participate in the maintenance of rest position of mandible and the realization of mandibular movements. The coordination of muscular activities among mandibular asymmetry patients is poorer than that among normal adults.

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. Copyright © 2016 Elsevier B.V. All rights reserved.

More Than Ataxia: Hyperkinetic Movement Disorders in Childhood Autosomal Recessive Ataxia Syndromes.

PubMed

Pearson, Toni S

2016-01-01

The autosomal recessive ataxias are a heterogeneous group of disorders that are characterized by complex neurological features in addition to progressive ataxia. Hyperkinetic movement disorders occur in a significant proportion of patients, and may sometimes be the presenting motor symptom. Presentations with involuntary movements rather than ataxia are diagnostically challenging, and are likely under-recognized. A PubMed literature search was performed in October 2015 utilizing pairwise combinations of disease-related terms (autosomal recessive ataxia, ataxia-telangiectasia, ataxia with oculomotor apraxia type 1 (AOA1), ataxia with oculomotor apraxia type 2 (AOA2), Friedreich ataxia, ataxia with vitamin E deficiency), and symptom-related terms (movement disorder, dystonia, chorea, choreoathetosis, myoclonus). Involuntary movements occur in the majority of patients with ataxia-telangiectasia and AOA1, and less frequently in patients with AOA2, Friedreich ataxia, and ataxia with vitamin E deficiency. Clinical presentations with an isolated hyperkinetic movement disorder in the absence of ataxia include dystonia or dystonia with myoclonus with predominant upper limb and cervical involvement (ataxia-telangiectasia, ataxia with vitamin E deficiency), and generalized chorea (ataxia with oculomotor apraxia type 1, ataxia-telangiectasia). An awareness of atypical presentations facilitates early and accurate diagnosis in these challenging cases. Recognition of involuntary movements is important not only for diagnosis, but also because of the potential for effective targeted symptomatic treatment.

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.

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

PubMed

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.

Electromyography of the buccal musculature of octopus (Octopus bimaculoides): a test of the function of the muscle articulation in support and movement.

PubMed

Uyeno, Theodore A; Kier, William M

2007-01-01

The buccal mass musculature of the octopus (Octopus bimaculoides) was studied with electromyography to test the predictions of a previous morphological study in which we suggested that the muscles of the buccal mass serve as both the effectors of movement and as the joint itself, forming a new category of flexible joint termed a ;muscle articulation'. The predictions of muscle function were tested by correlating muscle electrical activity in isolated buccal masses with spontaneous beak movements. Bipolar electromyography electrodes were implanted in the various beak muscles and beak position was recorded simultaneously with an electronic movement monitor (N=14). The results are consistent with the hypothesis that the lateral mandibular muscles produce opening movements of the beaks and provide the first definitive explanation of the opening mechanism. The results are also consistent with the hypothesis that the superior mandibular muscle functions primarily in closing. Co-contraction of the lateral mandibular muscles and the superior mandibular muscles was also observed, suggesting that these muscles may also stabilize the beaks during movement or provide a means of controlling the location of the pivot between the beaks. This study provides an important first test of the predictions of the role of the complex musculature found in muscle articulations such as the cephalopod buccal mass.

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.

Is muscle coordination affected by loading condition in ballistic movements?

PubMed

Giroux, Caroline; Guilhem, Gaël; Couturier, Antoine; Chollet, Didier; Rabita, Giuseppe

2015-02-01

This study aimed to investigate the effect of loading on lower limb muscle coordination involved during ballistic squat jumps. Twenty athletes performed ballistic squat jumps on a force platform. Vertical force, velocity, power and electromyographic (EMG) activity of lower limb muscles were recorded during the push-off phase and compared between seven loading conditions (0-60% of the concentric-only maximal repetition). The increase in external load increased vertical force (from 1962 N to 2559 N; P=0.0001), while movement velocity decreased (from 2.5 to 1.6 ms(-1); P=0.0001). EMG activity of tibialis anterior first peaked at 5% of the push-off phase, followed by gluteus maximus (35%), vastus lateralis and soleus (45%), rectus femoris (55%), gastrocnemius lateralis (65%) and semitendinosus (75%). This sequence of activation (P=0.67) and the amplitude of muscle activity (P=0.41) of each muscle were not affected by loading condition. However, a main effect of muscle was observed on these parameters (peak value: P<0.001; peak occurrence: P=0.02) illustrating the specific role of each muscle during the push-off phase. Our findings suggest that muscle coordination is not influenced by external load during a ballistic squat jump. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neuromuscular electrical stimulation of the hindlimb muscles for movement therapy in a rodent model.

PubMed

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

2009-01-30

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 75 Hz 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.

The effects of tetracaine on charge movement in fast twitch rat skeletal muscle fibres.

PubMed

Hollingworth, S; Marshall, M W; Robson, E

1990-02-01

1. The effects of tetracaine, a local anaesthetic that inhibits muscle contraction, on membrane potential and intramembrane charge movements were investigated in fast twitch rat muscle fibres (extensor digitorum longus). 2. The resting membrane potentials of surface fibres from muscles bathed in isotonic Ringer solution containing 2 mM-tetracaine were well maintained, but higher concentrations of tetracaine caused a time-dependent fall of potential. Muscle fibres bathed in hypertonic solutions containing 2 mM-tetracaine were rapidly depolarized. In both isotonic and hypertonic solutions, the depolarizing effect of tetracaine could not be reversed. 3. Charge movement measurements were made using the middle-of-the-fibre voltage clamp technique. The voltage dependence of charge movements measured in cold isotonic solutions was well fitted by a Boltzmann distribution (Q(V) = Qmax/(1 + exp(-(V-V)/k] where Qmax = 37.3 +/- 2.8 nC muF-1, V = -17.9 +/- 1.2 mV and k = 12.6 +/- 0.8 mV (n = 6, 2 degrees C; means +/- S.E. of means). Similar values were obtained when 2 mM-tetracaine was added to the isotonic bathing fluid (Qmax = 40.6 +/- 2.3 nC microF-1, V = -14.1 +/- 1.3 mV, k = 15.3 +/- 0.8 mV; n = 8, 2 degrees C). 4. Charge movements measured around mechanical threshold in muscle fibres bathed in hypertonic solutions were reduced when 2 mM-tetracaine was added to the bathing fluid. The tetracaine-sensitive component of charge was well fitted with an unconstrained Boltzmann distribution which gave: Qmax = 7.5 nC microF-1, V = -46.5 mV, k = 5.5 mV. The e-fold rise of the foot of the curve was 9.3 mV.

The effects of tetracaine on charge movement in fast twitch rat skeletal muscle fibres.

PubMed Central

Hollingworth, S; Marshall, M W; Robson, E

1990-01-01

1. The effects of tetracaine, a local anaesthetic that inhibits muscle contraction, on membrane potential and intramembrane charge movements were investigated in fast twitch rat muscle fibres (extensor digitorum longus). 2. The resting membrane potentials of surface fibres from muscles bathed in isotonic Ringer solution containing 2 mM-tetracaine were well maintained, but higher concentrations of tetracaine caused a time-dependent fall of potential. Muscle fibres bathed in hypertonic solutions containing 2 mM-tetracaine were rapidly depolarized. In both isotonic and hypertonic solutions, the depolarizing effect of tetracaine could not be reversed. 3. Charge movement measurements were made using the middle-of-the-fibre voltage clamp technique. The voltage dependence of charge movements measured in cold isotonic solutions was well fitted by a Boltzmann distribution (Q(V) = Qmax/(1 + exp(-(V-V)/k] where Qmax = 37.3 +/- 2.8 nC muF-1, V = -17.9 +/- 1.2 mV and k = 12.6 +/- 0.8 mV (n = 6, 2 degrees C; means +/- S.E. of means). Similar values were obtained when 2 mM-tetracaine was added to the isotonic bathing fluid (Qmax = 40.6 +/- 2.3 nC microF-1, V = -14.1 +/- 1.3 mV, k = 15.3 +/- 0.8 mV; n = 8, 2 degrees C). 4. Charge movements measured around mechanical threshold in muscle fibres bathed in hypertonic solutions were reduced when 2 mM-tetracaine was added to the bathing fluid. The tetracaine-sensitive component of charge was well fitted with an unconstrained Boltzmann distribution which gave: Qmax = 7.5 nC microF-1, V = -46.5 mV, k = 5.5 mV. The e-fold rise of the foot of the curve was 9.3 mV. PMID:2348406

26 CFR 1.381(c)(13)-1 - Involuntary conversions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 4 2010-04-01 2010-04-01 false Involuntary conversions. 1.381(c)(13)-1 Section...) INCOME TAX (CONTINUED) INCOME TAXES Insolvency Reorganizations § 1.381(c)(13)-1 Involuntary conversions... involuntary conversions. This rule shall apply even though the property similar or related in service or use...

26 CFR 1.381(c)(13)-1 - Involuntary conversions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 4 2011-04-01 2011-04-01 false Involuntary conversions. 1.381(c)(13)-1 Section...) INCOME TAX (CONTINUED) INCOME TAXES Insolvency Reorganizations § 1.381(c)(13)-1 Involuntary conversions... involuntary conversions. This rule shall apply even though the property similar or related in service or use...

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...

47 CFR 27.1252 - Involuntary Relocation Procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... agreement is reached during the mandatory negotiation period, an AWS licensee may initiate involuntary relocation procedures under the Commission's rules. AWS licensees are obligated to pay to relocate BRS systems to which the AWS system poses an interference problem. Under involuntary relocation, the BRS...

Involuntary psychiatric hospitalization and its relationship to psychopathology and aggression.

PubMed

Canova Mosele, Pedro Henrique; Chervenski Figueira, Guillierme; Antônio Bertuol Filho, Amadeu; Ferreira de Lima, José Antônio Reis; Calegaro, Vitor Crestani

2018-04-12

The current study investigates the relationship between involuntary hospitalization, severity of psychopathology, and aggression. Adult psychiatric inpatients hospitalized from August, 2012 to January, 2013 were evaluated via the Brief Psychiatric Rating Scale (BPRS) and the Overt Aggression Scale (OAS). Individuals were compared regarding voluntariness of hospitalization. Of the 137 hospitalizations in the period, 71 were involuntary (INV). The variables associated with involuntariness were being brought to hospital by ambulance or police, and aggression in the first 24 h of admission. Risk of suicide at admission, and having personal income were associated with voluntariness. The dimensions of the BPRS associated with involuntary hospitalization were activation, resistance, and positive symptoms. Involuntary psychiatric hospitalization was associated with agitation, psychosis and aggression. The data support the indication of involuntary hospitalization for treatment of patients with severe mental illness. Copyright © 2018. Published by Elsevier B.V.

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.

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

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.

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

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…

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

Post-stroke Movement Disorders: Clinical Manifestations and Pharmacological Management.

PubMed

Siniscalchi, Antonio; Gallelli, Luca; Labate, Angelo; Malferrari, Giovanni; Palleria, Caterina; Sarro, Giovambattista De

2012-09-01

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.

Protein-calorie malnutrition and involuntary weight loss: the role of aggressive nutritional intervention in wound healing.

PubMed

Himes, D

1999-03-01

Protein-calorie malnutrition and involuntary weight loss continue to be prevalent among hospitalized and long-term care patients, particularly the elderly. Studies on nutritional intervention have established a correlation between nutritional status, body weight, and rate of wound healing. Nutritional intervention, however, must be provided early enough to prevent a catabolic-induced decline in lean muscle mass, which can further impair wound healing. Chronic, nonhealing wounds are particularly difficult to treat and contribute to significant morbidity, mortality, and hospitalizations. More aggressive nutritional management and a greater understanding of the role of nutrition and weight gain in wound healing can result in more effective patient care. This article discusses the role of protein-calorie malnutrition and involuntary weight loss in hindering the wound-healing process, and the need to establish an optimal anabolic environment for weight gain and improved wound healing.

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.

Muscle load in reaching movements performed by a wheelchair user: a case study.

PubMed

van Drongelen, S; Wolf, S I; Fradet, L

2014-01-01

The aim of this study was to analyse the load on the shoulder muscles during reaching movements that are specific to wheelchair users in relation to the risk of impingement. Three activities of daily living were performed: putting a book on a shelf in front and at the side and putting a pack of water bottles on a table. The AnyBody shoulder model was used to calculate the activity and forces of the shoulder muscles. Handling the pack of bottles caused the highest forces in the deltoideus, trapezius, serratus anterior and rotator cuff muscles. For handling the book, the highest forces were found in the deltoideus (scapular part) and the serratus anterior, especially during the put phase. Handling heavy objects such as a pack of bottles or a wheelchair produces high forces on the rotator cuff muscles and can lead to early fatigue. Therefore, these activities seem to be associated with a high risk of developing impingement syndrome. Implications for Rehabilitation In a single patient, this study demonstrates that the load on the rotator cuff is high during reaching movements. Handling a pack of water bottles, which resembles wheelchair handling, represents an activity associated with a high risk of developing impingement syndrome. Shoulder muscles must be trained in a balanced way to provide stabilization at the shoulder joint and prevent fatigue.

The influence of altered working-side occlusal guidance on masticatory muscles and related jaw movement.

PubMed

Belser, U C; Hannam, A G

1985-03-01

The effect of four different occlusal situations (group function, canine guidance, working side occlusal interference, and hyperbalancing occlusal interference) on EMG activity in jaw elevator muscles and related mandibular movement was investigated on 12 subjects. With a computer-based system, EMG and displacement signals were collected simultaneously during specific functional (unilateral chewing) and parafunctional tasks (mandibular gliding movements and various tooth clenching efforts) and analyzed quantitatively. When a naturally acquired group function was temporarily and artificially changed into a dominant canine guidance, a significant general reduction of elevator muscle activity was observed when subjects exerted full isometric tooth-clenching efforts in a lateral mandibular position. The original muscular coordination pattern (relative contraction from muscle to muscle) remained unaltered during this test. With respect to unilateral chewing, no significant alterations in the activity or coordination of the muscles occurred when an artificial canine guidance was introduced. Introduction of a hyperbalancing occlusal contact caused significant alterations in muscle activity and coordination during maximal tooth clenching in a lateral mandibular position. A marked shift of temporal muscle EMG activity toward the side of the interference and unchanged bilateral activity of the two masseter muscles were observed. The results suggest that canine-protected occlusions do not significantly alter muscle activity during mastication but significantly reduce muscle activity during parafunctional clenching. They also suggest that non-working side contacts dramatically alter the distribution of muscle activity during parafunctional clenching, and that this redistribution may affect the nature of reaction forces at the temporomandibular joints.

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.

EXTRAOCULAR MUSCLE ACTIVITY, RAPID EYE MOVEMENTS, AND THE DEVELOPMENT OF ACTIVE AND QUIET SLEEP

PubMed Central

Seelke, Adele M. H.; Karlsson, Karl Æ.; Gall, Andrew J.; Blumberg, Mark S.

2008-01-01

Rapid eye movements (REMs), traditionally measured using the electrooculogram (EOG), help to characterize active sleep in adults. In early infancy, however, they are not clearly expressed. Here we measure extraocular muscle activity in infant rats at 3 days of age (P3), P8, and P14–15 in order to assess the ontogeny of REMs and their relationship with other forms of sleep-related phasic activity. We find that the causal relationship between extraocular muscle twitches and REMs strengthens during the first two postnatal weeks, reflecting increased control of the extraocular muscles over eye movements. As early as P3, however, phasic bursts of extraocular muscle twitching occur in synchrony with twitching in other muscle groups, producing waves of phasic activity interspersed with brief periods of quiescence. Surprisingly, the tone of the extraocular muscles, invisible to standard EOG measures, fluctuates in synchrony with the tone of other muscle groups; focal electrical stimulation within the dorsolateral pontine tegmentum, an area that has been shown to contain wake-on neurons in P8 rats, results in the simultaneous activation of high tone in both nuchal and extraocular muscles. Finally, when state-dependent neocortical electroencephalographic activity was observed at P14, it had already integrated fully with sleep and wakefulness as defined using electromyographic criteria alone; this finding is not consistent with the notion that active sleep in infants at this age is “half-activated.” All together, these results indicate exquisite temporal organization of sleep soon after birth and highlight the possible functional implications of homologous activational states in striated muscle and neocortex. PMID:16115214

Effect of movement velocity during resistance training on muscle-specific hypertrophy: A systematic review.

PubMed

Hackett, Daniel A; Davies, Timothy B; Orr, Rhonda; Kuang, Kenny; Halaki, Mark

2018-05-01

Currently, it is unclear whether manipulation of movement velocity during resistance exercise has an effect on hypertrophy of specific muscles. The purpose of this systematic review of literature was to investigate the effect of movement velocity during resistance training on muscle hypertrophy. Five electronic databases were searched using terms related to movement velocity and resistance training. Inclusion criteria were randomised and non-randomised comparative studies; published in English; included healthy adults; used dynamic resistance exercise interventions directly comparing fast training to slower movement velocity training; matched in prescribed intensity and volume; duration ≥4 weeks; and measured muscle hypertrophy. A total of six studies were included involving 119 untrained participants. Hypertrophy of the quadriceps was examined in five studies and of the biceps brachii in two studies. Three studies found significantly greater increases in hypertrophy of the quadriceps for moderate-slow compared to fast training. For the remaining studies examining the quadriceps, significant within-group increase in hypertrophy was found for only moderate-slow training in one study and for only fast training in the other study. The two studies that examined hypertrophy of the biceps brachii found greater increases for fast compared to moderate-slow training. Caution is required when interpreting the findings from this review due to the low number of studies, hence insufficient data. Future longitudinal randomised controlled studies in cohorts of healthy adults are required to confirm and extend our findings.

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…

Comparison of rhythmic masticatory muscle activity during non-rapid eye movement sleep in guinea pigs and humans.

PubMed

Kato, Takafumi; Toyota, Risa; Haraki, Shingo; Yano, Hiroyuki; Higashiyama, Makoto; Ueno, Yoshio; Yano, Hiroshi; Sato, Fumihiko; Yatani, Hirofumi; Yoshida, Atsushi

2017-09-27

Rhythmic masticatory muscle activity can be a normal variant of oromotor activity, which can be exaggerated in patients with sleep bruxism. However, few studies have tested the possibility in naturally sleeping animals to study the neurophysiological mechanisms of rhythmic masticatory muscle activity. This study aimed to investigate the similarity of cortical, cardiac and electromyographic manifestations of rhythmic masticatory muscle activity occurring during non-rapid eye movement sleep between guinea pigs and human subjects. Polysomnographic recordings were made in 30 freely moving guinea pigs and in eight healthy human subjects. Burst cycle length, duration and activity of rhythmic masticatory muscle activity were compared with those for chewing. The time between R-waves in the electrocardiogram (RR interval) and electroencephalogram power spectrum were calculated to assess time-course changes in cardiac and cortical activities in relation to rhythmic masticatory muscle activity. In animals, in comparison with chewing, rhythmic masticatory muscle activity had a lower burst activity, longer burst duration and longer cycle length (P < 0.05), and greater variabilities were observed (P < 0.05). Rhythmic masticatory muscle activity occurring during non-rapid eye movement sleep [median (interquartile range): 5.2 (2.6-8.9) times per h] was preceded by a transient decrease in RR intervals, and was accompanied by a transient decrease in delta elelctroencephalogram power. In humans, masseter bursts of rhythmic masticatory muscle activity were characterized by a lower activity, longer duration and longer cycle length than those of chewing (P < 0.05). Rhythmic masticatory muscle activity during non-rapid eye movement sleep [1.4 (1.18-2.11) times per h] was preceded by a transient decrease in RR intervals and an increase in cortical activity. Rhythmic masticatory muscle activity in animals had common physiological components representing transient arousal

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.

Calcium currents, charge movement and dihydropyridine binding in fast- and slow-twitch muscles of rat and rabbit.

PubMed Central

Lamb, G D; Walsh, T

1987-01-01

1. The Vaseline-gap technique was used to record slow calcium currents and asymmetric charge movement in single fibres of fast-twitch muscles (extensor digitorum longus (e.d.l.) and sternomastoid) and slow-twitch muscles (soleus) from rat and rabbit, at a holding potential of -90 mV. 2. The slow calcium current in soleus fibres was about one-third of the size of the current in e.d.l. fibres, but was very similar otherwise. In both e.d.l. and soleus fibres, the dihydropyridine (DHP), nifedipine, suppressed the calcium current entirely. 3. In these normally polarized fibres, nifedipine suppressed only part (qns) of the asymmetric charge movement. The proportion of qns suppressed by various concentrations of nifedipine was linearly related to the associated reduction of the calcium current. Half-maximal suppression of both parameters was obtained with about 0.5 microM-nifedipine. The calcium current and the qns component of the charge movement also were suppressed over the same time course by nifedipine. Another DHP calcium antagonist, (+)PN200/110, was indistinguishable from nifedipine in its effects of suppressing calcium currents and qns. 4. In all muscle types, the total amount of qns in each fibre was linearly related to the size of the calcium current (in the absence of DHP). On average, qns was 3.3 times larger in e.d.l. fibres than in soleus fibres. 5. In contrast to the other dihydropyridines, (-)bay K8644, a calcium channel agonist, did not suppress any asymmetric charge movement. 6. The potential dependence of the slow calcium current implied a minimum gating charge of about five or six electronic charges. The movement of qns occurred over a more negative potential range than the change in calcium conductance. 7. Experiments on the binding of (+)PN200/110 indicated that e.d.l. muscles had between about 2 and 3 times more specific DHP binding sites than did soleus muscle. 8. These results point to a close relationship between slow calcium channels, the qns

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

26 CFR 1.1033(a)-1 - Involuntary conversions; nonrecognition of gain.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Involuntary conversions; nonrecognition of gain... Involuntary conversions; nonrecognition of gain. (a) In general. Section 1033 applies to cases where property is compulsorily or involuntarily converted. An involuntary conversion may be the result of the...

26 CFR 1.1033(a)-1 - Involuntary conversions; nonrecognition of gain.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 11 2011-04-01 2011-04-01 false Involuntary conversions; nonrecognition of gain...)-1 Involuntary conversions; nonrecognition of gain. (a) In general. Section 1033 applies to cases where property is compulsorily or involuntarily converted. An involuntary conversion may be the result...

[The Activation of Interlimb Interactions Increase the Motor Output in Legs in Healthy Subjects under the Conditions of Arm and Leg Unloading].

PubMed

Selionov, V A; Solopova, I A; Zhvansky, D S

2016-01-01

We studied the effect of arm movements and movements of separate arm joints on the electrophysiological and kinematic characteristics of voluntary and vibration-triggered stepping-like leg movements under the conditions of horizontal support of upper and lower limbs. The horizontal support of arms provided a significantly increase in the rate of activation of locomotor automatism by non-invasive impact on tonic sensory inputs. The addition of active arm movements during involuntary rhytmic stepping-like leg movements led to an increase in EMG activity of hip muscles and was accompanied by an increase in the amplitude of hip and shin movements. Passive arm movements had the same effect on induced leg movements. The movement of the shoulder joints led to an increase in the activity of hip muscles and an increase in the amplitude of movements of the knee and hip joints. At the same time, the movement of forearms. and wrists had similar facilitating effect on electrophysiological and kinematic characteristics of rhytmic stepping-like movements, but influenced the distal segments of legs to a greater extent. Under the conditions of sub-threshold vibration of leg muscles, voluntary arm movements led to the activation of involuntary rhytmic stepping movements. During voluntary leg movements, the addition of arm movements had a significantly smaller impact on the parameters of rhytmic stepping than during involuntary leg movements. Thus, the simultaneous movements of upper and lower limbs are an effective method of activation of neural networks connecting the rhythm generators of arms and legs. Under the conditions of arm and leg unloading, the interactions between the cervical and lumbosacral segments of the spinal cord seem to play the major role in the impact of arm movements on the patterns of leg movements. The described methods of activation of interlimb interactions can be used in the rehabilitation of post-stroke patients and patients with spinal cord injuries

Neural mechanisms of voluntary and involuntary recall: a PET study.

PubMed

Hall, Nicoline Marie; Gjedde, Albert; Kupers, Ron

2008-01-25

Neuropsychological and neuroimaging studies on episodic memory retrieval have primarily focused on volitional memory tasks. However, some conscious memories arise involuntarily, i.e. without a strategic retrieval attempt, yet little is known about the neural network underlying involuntary episodic memory. The aim of this study was to determine whether voluntary and involuntary recall are mediated by separate cortical networks. We used positron emission tomography (PET) to measure changes in regional cerebral blood flow (rCBF) in 12 healthy subjects during voluntary and involuntary cued recall of pictures and a control condition with no episodic memory requirements. Involuntary recall was elicited by using an incidental memory task. Compared to the control condition, voluntary and involuntary recall were both associated with significant regional cerebral blood flow (rCBF) increases in posterior cingulate gyrus (PCG; BA 23), left precuneus (BA 7), and right parahippocampal gyrus (BA 35/36). In addition, rCBF in right dorsolateral prefrontal cortex (PFC; BA 8/9) and left precuneus (BA 7) was significantly larger during voluntary compared to involuntary recall, while rCBF was enhanced in left dorsolateral PFC (BA 9) during involuntary recall. The findings corroborate an association of the right PFC with a strategic component of episodic memory retrieval. Moreover, they show for the first time that it is possible to activate the medial temporal lobe, the PCG, and the precuneus, regions normally associated with retrieval success, without this strategic element. The relatively higher activity in precuneus during voluntary compared to involuntary recall suggests that activity in this region co-varies not only with retrieval success but also with retrieval intentionality.

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.

The responses of muscle spindles to small, slow movements in passive muscle and during fusimotor activity.

PubMed

Wise, A K; Gregory, J E; Proske, U

1999-03-06

We have previously shown that movement detection thresholds at the human elbow joint were less than a degree of joint rotation in the passive limb but were higher if they were measured while subjects co-contracted elbow muscles [A.K. Wise, J.E. Gregory, U. Proske, J. Physiol., 508 (1998) 325-330]. Here we report observations on the responses of muscle spindles of the soleus muscle of the anaesthetised cat to determine their ability to signal small length changes in the passive muscle and during a contraction, under conditions resembling those of the human experiments. After appropriate conditioning of the muscle to control for history effects, primary endings of muscle spindles showed thresholds to ramp stretch at 20 micrometers s-1 of between less than 5 micrometers and 15 micrometers, which translates to 0.05 degrees -0.15 degrees of human elbow joint rotation. Thresholds were much higher following conditioning to introduce slack in the muscle. Since during a voluntary contraction there is likely to be alpha:gamma co-activation, responses of spindles were also recorded during slow stretches (100 micrometers at 20 micrometers s-1) during static fusimotor stimulation, dynamic fusimotor stimulation, combined fusimotor stimulation and fusimotor plus skeletomotor stimulation. Invariably, responses to passive stretch were larger than during motor stimulation. It is concluded that spindles are sensitive enough to signal fractions of a degree of elbow joint rotation and that the rise in threshold observed during a voluntary contraction may be accounted for by the actions of fusimotor and skeletomotor axons on spindle stretch responses. Copyright 1999 Elsevier Science B.V.

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

Muscle Activation During ACL Injury Risk Movements in Young Female Athletes: A Narrative Review.

PubMed

Bencke, Jesper; Aagaard, Per; Zebis, Mette K

2018-01-01

Young, adolescent female athletes are at particular high risk of sustaining a non-contact anterior cruciate ligament (ACL) injury during sport. Through the last decades much attention has been directed toward various anatomical and biomechanical risk factors for non-contact ACL injury, and important information have been retrieved about the influence of external loading factors on ACL injury risk during given sports-specific movements. However, much less attention has been given to the aspect of neuromuscular control during such movements and only sparse knowledge exists on the specific muscle activation patterns involved during specific risk conditions. Therefore, the aim of this narrative review was (1) to describe anatomical aspects, strength aspects and biomechanical aspects relevant for the understanding of ACL non-contact injury mechanisms in young female athletes, and (2) to review the existing literature on lower limb muscle activation in relation to risk of non-contact ACL-injury and prevention of ACL injury in young female athletes. Studies investigating muscle activity patterns associated with sports-specific risk situations were identified, comprising cohort studies, intervention studies and prospective studies. Based on the retrieved studies, clear gender-specific differences in muscle activation and coordination were identified demonstrating elevated quadriceps activity and reduced hamstring activity in young female athletes compared to their male counterparts, and suggesting young female athletes to be at elevated risk of non-contact ACL injury. Only few studies ( n = 6) examined the effect of preventive exercise-based intervention protocols on lower limb muscle activation during sports-specific movements. A general trend toward enhanced hamstring activation was observed during selected injury risk situations (e.g., sidecutting and drop landings). Only a single study examined the association between muscle activation deficits and ACL injury risk

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... § 1.121-5 for special rules relating to the involuntary conversion of a principal residence of...

Nicolaus Steno's new myology (1667): rather than muscle, the motorfibre should be called animal's organ of movement.

PubMed

Kardel, Troels

2008-01-01

Muscular movement is the result of fibre shortening. How did this basic insight arise? Based on several of his observations, Nicolaus Steno in 1664 and 1667 proposed that muscles shorten when fibres shorten, and that skeletal muscles consist of uniform motor fibres layered as pennate structures. The basis for a new myology was provided in a geometrical model of the movement of the muscles. But fibre shortening was incompatible with the dominant ancient theory of contraction by inflation that was favoured by Descartes and by Steno's contemporaries William Croone, Thomas Willis, John Mayow, and Giovanni Borelli due to their adherence to the Aristotelian axiom: "Anything which moves is moved by something else". The inflation theory blindfolded researchers well into the eighteenth century for skeletal and heart muscles. When the shortening of motor fibres was eventually visualised by microscopy, this inflation theory was no longer tenable. Steno's structural claim on skeletal muscles was also rejected by Borelli and by later commentators. Pennate muscles were only rarely displayed until 1981 when macro-anatomical studies showed the morphology of most skeletal muscles to be similar to that described by Steno. Steno's proposals on muscles have since become a common-place in computer models applied in the study of human and animal motion.

Sex differences in kinematic adaptations to muscle fatigue induced by repetitive upper limb movements.

PubMed

Bouffard, Jason; Yang, Chen; Begon, Mickael; Côté, Julie

2018-04-19

Muscle fatigue induced by repetitive movements contributes to the development of musculoskeletal disorders. Men and women respond differently to muscle fatigue during isometric single-joint efforts, but sex differences during dynamic multi-joint tasks have not been clearly identified. Moreover, most studies comparing men and women during fatigue development assessed endurance time. However, none evaluated sex differences in kinematic adaptations to fatigue during multi-joint dynamic tasks. The objective of the study was to compare how men and women adapt their upper body kinematics during a fatiguing repetitive pointing task. Forty men and 41 women performed repetitive pointing movements (one per second) between two targets while maintaining their elbow elevated at shoulder height. The task ended when participants rated a perceived level of fatigue of 8/10. Trunk, humerothoracic, and elbow angles were compared between the first and last 30 s of the experiment and between men and women. Linear positions of the index finger (distance from the target) and the elbow (arm elevation) as well as movement timing were documented as task performance measures. Men (7.4 ± 3.2 min) and women (8.3 ± 4.5 min) performed the repetitive pointing task for a similar duration. For both sex groups, trunk range of motion increased with fatigue while shoulder's and elbow's decreased. Moreover, participants modified their trunk posture to compensate for the decreased humerothoracic elevation. Movements at all joints also became more variable with fatigue. However, of the 24 joint angle variables assessed, only two Sex × Fatigue interactions were observed. Although average humerothoracic elevation angle decreased in both subgroups, this decrease was greater in men (standardized response mean [SRM] - 1.63) than in women (SRM - 1.44). Moreover, the movement-to-movement variability of humerothoracic elevation angle increased only in women (SRM 0.42). Despite many similarities

Muscular patterns and activation levels of auxiliary breathing muscles and thorax movement in classical singing.

PubMed

Pettersen, Viggo

2005-01-01

The aim of this paper is to present an overview of the findings in seven studies exploring muscular patterns and muscle activation levels in selected muscles by classical singers. In addition, the relationship of these muscles to thorax (TX) movement was investigated. Loading levels and respiratory phasing of upper trapezius (TR), sternocleidomastoideus (STM) and the scalenes (SC) were investigated in vocalization tasks with variation in vocal loudness and pitch. Further, muscle activity in the posterior neck (PN) was investigated in inhalation and phonation and, finally, TR, intercostal (INT), lateral abdominal (OBL) and anterior abdominal (RC) muscle loading in student and professional singers was examined. Muscle activity was recorded by use of an ambulatory four-channel monitoring system (Physiometer PHY 400, Premed, Norway). TX movement was traced with two strain gauge sensors (RES-117) placed around the upper TX and lower TX. A phasing of upper TR activity to INT and OBL activity was discovered, all muscles supporting the expiration phase. During phonation, TR contributes in the compression of the upper TX, thus serving as an accessory muscle of expiration. TR activity is reduced with short breathing cycles and is mostly inactive in simplified speaking tasks. During phonation, professional opera singers activate the expiratory-phased TR, INT, OBL and RC muscles to higher levels than student singers do. STM and SC show correlated activity patterns during inhalation and phonation by classical singers. During demanding singing, expiratory-phased STM and SC activity peaks produce a counterforce to the compression of upper TX at high pitches. As breathing demands are lowered, STM and SC activity are reduced and attain inspiratory phasing. Substantial muscle activity is observed in PN during inhalation and phonation. EMG biofeedback performed on TR and STM have a secondary effect of lowering EMG activity in PN. (c) 2005 S. Karger AG, Basel

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

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.

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.

Long-lasting involuntary motor activity after spinal cord injury.

PubMed

McKay, W B; Ovechkin, A V; Vitaz, T W; Terson de Paleville, D G L; Harkema, S J

2011-01-01

The study design used is prospective cohort study. This study was designed to neurophysiologically characterize spinal motor activity during recovery from spinal cord injury (SCI). University of Louisville, Louisville, Kentucky, USA. Twenty-five consecutive acute SCI admissions were recruited for this study. The American Spinal Injury Association Impairment Scale (AIS) was used to categorize injury level and severity at onset. Surface EMG recording was carried out initially between the day of admission and 17 days post-onset (6.0 ± 4.3, mean ± s.d. days). Follow-up recordings were performed for up to 9 months after injury. Initial AIS distribution was 7 AIS-A; 3 AIS-B; 2 AIS-C; 13 AIS-D. Twelve subjects (48%) showed long-duration involuntary motor-unit activation during relaxation. This activity was seen on initial examination in nine and on follow-up by 3 months post-injury in three others. It was seen in muscles innervated from the injury zone in 11 and caudal to the lesion in 9 subjects. This activity was independent of the presence or absence of tendon reflexes and the ability to volitionally suppress plantar stimulation elicited reflex withdrawal. The form of involuntary activity described here is the likely result of the altered balance of excitation and inhibition reaching spinal motor neurons because of the loss of inhibitory interneurons or their reduced activation by damaged supraspinal drive and the synaptic reorganization that follows SCI. As such, this activity may be useful for monitoring the effects of neuroprotective and restorative intervention strategies in persons with SCI.

Long-lasting Involuntary Motor Activity After Spinal Cord Injury

PubMed Central

McKay, WB; Ovechkin, AV; Vitaz, TW; de Paleville, DGLTerson; Harkema, SJ

2010-01-01

Study Design Prospective cohort study Objective This study was designed to neurophysiologically characterize spinal motor activity during recovery from spinal cord injury (SCI). Setting University of Louisville, Louisville, Kentucky, USA. Material Twenty five consecutive acute SCI admissions were recruited for this study. Methods The American Spinal Injury Association Impairment Scale (AIS) was used to categorize injury level and severity at onset. Surface EMG recording, was carried out initially between the day of admission and 17 days post onset (6.0 ± 4.3, mean ± SD days). Follow-up recordings were performed for up to 9 months after injury. Initial AIS distribution was: 7 AIS-A; 3 AIS-B; 2 AIS-C; 13 AIS-D. Results Twelve subjects (48%) showed long-duration involuntary motor unit activation during relaxation. This activity was seen on initial examination in nine and on follow-up by three months post-injury in three others. It was seen in muscles innervated from the injury zone in 11 and caudal to the lesion in 9 subjects. This activity was independent of the presence or absence of tendon reflexes and the ability to volitionally suppress plantar stimulation elicited reflex withdrawal. Conclusions The form of involuntary activity described here is the likely result of the altered balance of excitation and inhibition reaching spinal motor neurons due to the loss of inhibitory interneurons or their reduced activation by damaged supraspinal drive and the synaptic reorganization that follows SCI. As such, this activity may be useful for monitoring the effects of neuroprotective and restorative intervention strategies in persons with SCI. PMID:20585326

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.

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.

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.

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.

Creutzfeldt-Jakob Disease

MedlinePlus

... damage leads to rapid decline in thinking and reasoning as well as involuntary muscle movements, confusion, difficulty ... been tested but have not shown any benefit. Clinical studies of potential CJD treatments are complicated by ...

Multilingual website and cyberconsultations for oromandibular dystonia

PubMed Central

Yoshida, Kazuya

2018-01-01

Oromandibular dystonia is a focal dystonia that manifests as involuntary masticatory and/or tongue muscle contractions. This movement disorder is frequently misdiagnosed as a temporomandibular disorder. Hence, it would be useful to establish a method that makes it possible for patients with the condition to find appropriate medical institutions by themselves. The author produced a website Involuntary movements of the stomatognathic region (https://sites. google.com/site/oromandibulardystoniaenglish/) for patients with oromandibular dystonia, which is available in twenty languages. It has been viewed more than 1,000,000 times by individuals from all over the world. The visitors to the site have completed questionnaires and/or sent images or videos of their involuntary movements over the internet. Cyberconsultations (remote diagnosis) were also performed via Skype™. Approximately 1000 patients with involuntary stomatognathic movements visited our department. Only 12.5% of the patients had previously been diagnosed with or were suspected to have dystonia. The findings of this study suggest that the multilingual website has contributed to increasing awareness of oromandibular dystonia and that the provision of basic telemedicine via the internet can aid the diagnosis and treatment of oromandibular dystonia. PMID:29844890

Multilingual website and cyberconsultations for oromandibular dystonia.

PubMed

Yoshida, Kazuya

2018-03-30

Oromandibular dystonia is a focal dystonia that manifests as involuntary masticatory and/or tongue muscle contractions. This movement disorder is frequently misdiagnosed as a temporomandibular disorder. Hence, it would be useful to establish a method that makes it possible for patients with the condition to find appropriate medical institutions by themselves. The author produced a website Involuntary movements of the stomatognathic region (https://sites. google.com/site/oromandibulardystoniaenglish/) for patients with oromandibular dystonia, which is available in twenty languages. It has been viewed more than 1,000,000 times by individuals from all over the world. The visitors to the site have completed questionnaires and/or sent images or videos of their involuntary movements over the internet. Cyberconsultations (remote diagnosis) were also performed via Skype ™ . Approximately 1000 patients with involuntary stomatognathic movements visited our department. Only 12.5% of the patients had previously been diagnosed with or were suspected to have dystonia. The findings of this study suggest that the multilingual website has contributed to increasing awareness of oromandibular dystonia and that the provision of basic telemedicine via the internet can aid the diagnosis and treatment of oromandibular dystonia.

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

Electromyographic Comparison of Forearm Muscle Movements for Fine Skin Suturing Between an Enlarged Pen Needle Holder and a Webster Needle Holder

PubMed Central

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

2013-01-01

Background: 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. Methods: 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. Results: 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. Conclusions: 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. PMID:23691259

Slow movement resistance training using body weight improves muscle mass in the elderly: A randomized controlled trial.

PubMed

Tsuzuku, S; Kajioka, T; Sakakibara, H; Shimaoka, K

2018-04-01

To examine the effect of a 12-week slow movement resistance training using body weight as a load (SRT-BW) on muscle mass, strength, and fat distribution in healthy elderly people. Fifty-three men and 35 women aged 70 years old or older without experience in resistance training participated, and they were randomly assigned to a SRT-BW group or control group. The control group did not receive any intervention, but participants in this group underwent a repeat measurement 12 weeks later. The SRT-BW program consisted of 3 different exercises (squat, tabletop push-up, and sit-up), which were designed to stimulate anterior major muscles. Initially, these exercises were performed by 2 sets of 10 repetitions, and subsequently, the number of repetitions was increased progressively by 2 repetitions every 4 weeks. Participants were instructed to perform each eccentric and concentric phase of movement slowly (spending 4 seconds on each movement), covering the full range of motion. We evaluated muscle mass, strength, and fat distribution at baseline and after 12 weeks of training. Changes over 12 weeks were significantly greater in the SRT-BW group than in the control group, with a decrease in waist circumference, hip circumference, and abdominal preperitoneal and subcutaneous fat thickness, and an increase in thigh muscle thickness, knee extension strength, and hip flexion strength. In conclusion, relatively short-term SRT-BW was effective in improving muscle mass, strength, and fat distribution in healthy elderly people. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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.

Asymmetric activation of motor cortex controlling human anterior digastric muscles during speech and target-directed jaw movements.

PubMed

Sowman, Paul F; Flavel, Stanley C; McShane, Christie L; Sakuma, Shigemitsu; Miles, Timothy S; Nordstrom, Michael A

2009-07-01

Like most of the cranial muscles involved in speech, the trigeminally innervated anterior digastric muscles are controlled by descending corticobulbar projections from the primary motor cortex (M1) of each hemisphere. We hypothesized that changes in corticobulbar M1 excitability during speech production would show a hemispheric asymmetry favoring the left side, which is the dominant hemisphere for language processing in most strongly right handed subjects. Fifteen volunteers aged 24.5+/-5.3 (SD) yr participated. All subjects were strongly right handed as reported by questionnaire. A surface electromyograph (EMG) was recorded bilaterally from digastrics and jaw movement detected by an accelerometer attached to a lower incisor. Focal transcranial magnetic stimulation (TMS) was used to assess corticomotor excitability of the digastric representation in M1 of both hemispheres during four tasks: 1) static isometric contraction of digastrics; 2) speaking a single word; 3) visually guided, nonspeech jaw movement that matched the jaw kinematics recorded during task 2; and 4) reciting a sentence. Background EMG was well matched in all tasks and jaw kinematics were similar around the time of the TMS pulse for tasks 2-4. TMS resting thresholds and digastric muscle-evoked potential (MEP) size during isometric contraction did not differ for TMS over left versus right M1. MEPs elicited by TMS over left, but not right M1 increased in size during speech and nonspeech jaw movement compared with isometric contraction. We conclude that left corticobulbar M1 is preferentially engaged for descending control of digastric muscles during speech and the performance of a rapid jaw movement to match a target kinematic profile.

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. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

The effects of stimulus-driven competition and task set on involuntary attention

PubMed Central

Han, Suk Won; Marois, René

2014-01-01

It is well established that involuntary attention—the exogenous capture of attention by salient but task-irrelevant stimuli—can strongly modulate target detection and discrimination performance. There is an ongoing debate, however, about how involuntary attention affects target performance. Some studies suggest that it results from enhanced perception of the target, whereas others indicate instead that it affects decisional stages of information processing. From a review of these studies, we hypothesized that the presence of distractors and task sets are key factors in determining the effect of involuntary attention on target perception. Consistent with this hypothesis, here we found that noninformative cues summoning involuntary attention affected perceptual identification of a target when distractors were present. This cuing effect could not be attributed to reduced target location uncertainty or decision bias. The only condition under which involuntary attention improved target perception in the absence of distractors occurred when observers did not adopt a task set to focus attention on the target location. We conclude that the perceptual effects of involuntary attention depend on distractor interference and the adoption of a task set to resolve such stimulus competition. PMID:24970921

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

PubMed

Vikne, Harald; Bakke, Eva Sigrid; Liestøl, Knut; Engen, Stian R; Vøllestad, Nina

2013-11-04

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. 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. 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. 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 importance in chronic WAD, movement smoothness of

A Developmental Study of the Influence of Task Characteristics on Motor Overflow

ERIC Educational Resources Information Center

Addamo, Patricia K.; Farrow, Maree; Hoy, Kate E.; Bradshaw, John L.; Georgiou-Karistianis, Nellie

2009-01-01

Motor overflow refers to involuntary movement or muscle activity that may coincide with voluntary movement. This study examined factors influencing motor overflow in 17 children (8-11 years), and 17 adults (18-35 years). Participants performed a finger pressing task by exerting either 33% or 66% of their maximal force output using their dominant…

Investigations of ocular changes, extraocular muscle thickness, and eye movements in Graves' ophthalmopathy.

PubMed

Jankauskiene, Jūrate; Imbrasiene, Daiva

2006-01-01

The aim of this study was to evaluate ocular changes, to measure the thickness of extraocular muscles, and to assess eye movements in patients with active Graves' ophthalmopathy. We examined 27 patients (18 women and 9 men) with Graves' ophthalmopathy. Their age ranged from 17 to 59 years; mean age was 42.7+/-2.9 years. The control group consisted of 30 healthy persons aged 43.6+/-2.6 years. All patients underwent a complete ophthalmic examination including best-corrected Snellen visual acuity testing, measurements of proptosis using Hertel exophthalmometer, echography using A/B mode Mentor Advent ultrasonic diagnostic imaging system, ocular motility, slit-lamp and ophthalmoscopic examination. The examination showed a significant increase of proptosis, periorbital edema in 66.67%, chemosis in 59.26%, injection of conjunctiva in 45.15% of patients. The majority of patients with infiltrative form of Graves' ophthalmopathy had a significant enlargement of medial rectus muscle (from 5.0 to 5.9 mm in 46.3%, from 6.0 to 6.9 mm in 22.22% of eyes) and inferior rectus muscle thickness (from 5.0 to 5.9 mm in 33.33%, from 6.0 to 6.9 mm in 24.07% of eyes), disturbances in upward (less than 30 degrees in 62.96%) and lateral eye movements (from 30 to 50 degrees in 77.78%). The results of ocular examination showed an increase of proptosis, periorbital edema, chemosis and injection of conjunctiva in patients with Graves' ophthalmopathy. Ultrasound investigations showed a marked increase in the volume of medial and inferior eye muscle. In patients with Graves' ophthalmopathy, the changes in ocular motility (upward and lateral gaze) were detected.

Organizational and environmental effects on voluntary and involuntary turnover.

PubMed

Donoghue, Christopher; Castle, Nicholas G

2007-01-01

There are few studies of voluntary and involuntary turnover in the nursing home literature. Previous research in this area has focused mainly on the linear effects of individual and organizational characteristics on total turnover. The purpose of this study was to examine both linear and nonlinear effects of organizational and environmental conditions on voluntary and involuntary nursing home staff turnover. We analyzed both primary and secondary data on 854 nursing homes in six states. A negative binomial regression model was used to study both linear and curvilinear effects of organizational and environmental factors on voluntary and involuntary turnover among registered nurses, licensed practical nurses, and nurse aides. Staffing levels and deficiency citations were the organizational characteristics most consistently linked with turnover among all nurse types. Links were also found between unemployment and type of location (urban or rural) and turnover, indicating that the economic environment is influential for retention. The results of this study support the notion that policy makers need to consider both the organization and the environment when evaluating the nature of nursing home staff turnover. The findings also offer further evidence that the antecedents of voluntary and involuntary turnover are not necessarily the same.

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

42 CFR 460.164 - Involuntary disenrollment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Enrollment and Disenrollment § 460.164 Involuntary disenrollment. (a) Reasons...

42 CFR 460.164 - Involuntary disenrollment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Enrollment and Disenrollment § 460.164 Involuntary disenrollment. (a) Reasons...

Risk factors for readmission in schizophrenia patients following involuntary admission.

PubMed

Hung, Yu-Yuan; Chan, Hung-Yu; Pan, Yi-Ju

2017-01-01

Individuals with schizophrenia who are involuntarily admitted may have poorer prognosis, including higher readmission rates, than those voluntarily admitted. However, little is known about the risk factors for readmission in those schizophrenia patients who are involuntarily admitted. We aim to explore the risk factors for readmission in this population. We enrolled 138 schizophrenia patients with involuntary admission from July 2008 to June 2013 and followed those patients for readmission outcomes at 3 months and at 1 year. The one-year and 3-months readmission rates were 33.3% and 15.2%, respectively. Unmarried status (adjusted odds ratio (aOR) = 6.28, 95% CI: 1.48-26.62), previous history of involuntary admission (aOR = 4.08, 95% CI: 1.19-14.02), longer involuntary admission days (aOR = 1.04, 95% CI: 1.01-1.07) and shorter total admission days (aOR = 1.03, 95% CI: 1.01-1.05) were associated with increased risk for 1-year readmission. Younger age (aOR = 1.10, 95% CI 1.02-1.18) was associated with increased risk for 3-months readmission. Unmarried status, prior history of involuntary admission, longer involuntary admission days and shorter total admission days were associated with increased risk for 1-year readmission. Healthcare providers may need to focus on patients with these risk factors to reduce subsequent readmissions.

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…

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.

Correlation between dopamine receptor D2 expression and presence of abnormal involuntary movements in Wistar rats with hemiparkinsonism and dyskinesia.

PubMed

Caro Aponte, P A; Otálora, C A; Guzmán, J C; Turner, L F; Alcázar, J P; Mayorga, E L

2018-03-07

Parkinson's disease (PD) is characterised by motor alterations, which are commonly treated with L-DOPA. However, long-term L-DOPA use may cause dyskinesia. Although the pathogenic mechanism of L-DOPA-induced dyskinesia is unclear, the condition has been associated with alterations in dopamine receptors, among which D2 receptors (D2R) have received little attention. This study aims to: (i)develop and standardise an experimental model of L-DOPA-induced dyskinesia in rats with hemiparkinsonism; and (ii)evaluate the correlation between D2R expression and presence of abnormal involuntary movements (AIM). We allocated 21 male Wistar rats into 3 groups: intact controls, lesioned rats (with neurotoxin 6-OHDA), and dyskinetic rats (injected with L-DOPA for 19 days). Sensorimotor impairment was assessed with behavioural tests. Dyskinetic rats gradually developed AIMs during the treatment period; front leg AIMs were more severe and locomotor AIMs less severe (P<.05). All AIMs were significantly evident from day 5 and persisted until the last day of injection. D2R density was greater in the striatum and the medial anterior brain of the lesioned and dyskinetic rats than in those of controls. Our results suggest an association between D2R expression and locomotor AIMs. We conclude that RD2 is involved in L-DOPA-induced dyskinesia. Copyright © 2018 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

How the mind shapes action: Offline contexts modulate involuntary episodic retrieval.

PubMed

Frings, Christian; Koch, Iring; Moeller, Birte

2017-11-01

Involuntary retrieval of previous stimulus-response episodes is a centerpiece of many theories of priming, episodic binding, and action control. Typically it is assumed that by repeating a stimulus from trial n-1 to trial n, involuntary retrieval is triggered in a nearly automatic fashion, facilitating (or interfering with) the to-be-executed action. Here we argue that changes in the offline context weaken the involuntary retrieval of previous episodes (the offline context is defined to be the information presented before or after the focal stimulus). In four conditions differing in cue modality and target modality, retrieval was diminished if participants changed the target selection criterion (as indicated by a cue presented before the selection took place) while they still performed the same task. Thus, solely through changes in the offline context (cue or selection criterion), involuntary retrieval can be weakened in an effective way.

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.

Neck movement and muscle activity characteristics in female office workers with neck pain.

PubMed

Johnston, V; Jull, G; Souvlis, T; Jimmieson, N L

2008-03-01

Cross-sectional study. To explore aspects of cervical musculoskeletal function in female office workers with neck pain. Evidence of physical characteristics that differentiate computer workers with and without neck pain is sparse. Patients with chronic neck pain demonstrate reduced motion and altered patterns of muscle control in the cervical flexor and upper trapezius (UT) muscles during specific tasks. Understanding cervical musculoskeletal function in office workers will better direct intervention and prevention strategies. Measures included neck range of motion; superficial neck flexor muscle activity during a clinical test, the craniocervical flexion test; and a motor task, a unilateral muscle coordination task, to assess the activity of both the anterior and posterior neck muscles. Office workers with and without neck pain were formed into 3 groups based on their scores on the Neck Disability Index. Nonworking women without neck pain formed the control group. Surface electromyographic activity was recorded bilaterally from the sternocleidomastoid, anterior scalene (AS), cervical extensor (CE) and UT muscles. Workers with neck pain had reduced rotation range and increased activity of the superficial cervical flexors during the craniocervical flexion test. During the coordination task, workers with pain demonstrated greater activity in the CE muscles bilaterally. On completion of the task, the UT and dominant CE and AS muscles demonstrated an inability to relax in workers with pain. In general, there was a linear relationship between the workers' self-reported levels of pain and disability and the movement and muscle changes. These results are consistent with those found in other cervical musculoskeletal disorders and may represent an altered muscle recruitment strategy to stabilize the head and neck. An exercise program including motor reeducation may assist in the management of neck pain in office workers.

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…

The non-motor syndrome of primary dystonia: clinical and pathophysiological implications

PubMed Central

Stamelou, Maria; Edwards, Mark J.; Hallett, Mark

2012-01-01

Dystonia is typically considered a movement disorder characterized by motor manifestations, primarily involuntary muscle contractions causing twisting movements and abnormal postures. However, growing evidence indicates an important non-motor component to primary dystonia, including abnormalities in sensory and perceptual functions, as well as neuropsychiatric, cognitive and sleep domains. Here, we review this evidence and discuss its clinical and pathophysiological implications. PMID:21933808

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

26 CFR 1.1033(a)-3 - Involuntary conversion of principal residence.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Involuntary conversion of principal residence. 1... conversion of principal residence. Section 1033 shall apply in the case of property used by the taxpayer as... for special rules relating to the involuntary conversion of a principal residence of individuals who...

Characteristics of locomotion, muscle strength, and muscle tissue in regenerating rat skeletal muscles.

PubMed

Iwata, Akira; Fuchioka, Satoshi; Hiraoka, Koichi; Masuhara, Mitsuhiko; Kami, Katsuya

2010-05-01

Although numerous studies have aimed to elucidate the mechanisms used to repair the structure and function of injured skeletal muscles, it remains unclear how and when movement recovers following damage. We performed a temporal analysis to characterize the changes in movement, muscle function, and muscle structure after muscle injury induced by the drop-mass technique. At each time-point, movement recovery was determined by ankle kinematic analysis of locomotion, and functional recovery was represented by isometric force. As a histological analysis, the cross-sectional area of myotubes was measured to examine structural regeneration. The dorsiflexion angle of the ankle, as assessed by kinematic analysis of locomotion, increased after injury and then returned to control levels by day 14 post-injury. The isometric force returned to normal levels by day 21 post-injury. However, the size of the myotubes did not reach normal levels, even at day 21 post-injury. These results indicate that recovery of locomotion occurs prior to recovery of isometric force and that functional recovery occurs earlier than structural regeneration. Thus, it is suggested that recovery of the movement and function of injured skeletal muscles might be insufficient as markers for estimating the degree of neuromuscular system reconstitution.

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…

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

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

PubMed

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.

The Low Proportion and Associated Factors of Involuntary Admission in the Psychiatric Emergency Service in Taiwan

PubMed Central

Wang, Jen-Pang; Chiu, Chih-Chiang; Yang, Tsu-Hui; Liu, Tzong-Hsien; Wu, Chia-Yi; Chou, Pesus

2015-01-01

Background The involuntary admission regulated under the Mental Health Act has become an increasingly important issue in the developed countries in recent years. Most studies about the distribution and associated factors of involuntary admission were carried out in the western countries; however, the results may vary in different areas with different legal and socio-cultural backgrounds. Aims The aim of this study was to investigate the proportion and associated factors of involuntary admission in a psychiatric emergency service in Taiwan. Methods The study cohort included patients admitted from a psychiatric emergency service over a two-year period. Demographic, psychiatric emergency service utilization, and clinical variables were compared between those who were voluntarily and involuntarily admitted to explore the associated factors of involuntary admission. Results Among 2,777 admitted patients, 110 (4.0%) were involuntarily admitted. Police referrals and presenting problems as violence assessed by psychiatric nurses were found to be associated with involuntary admission. These patients were more likely to be involuntarily admitted during the night shift and stayed longer in the psychiatric emergency service. Conclusions The proportion of involuntary admissions in Taiwan was in the lower range when compared to Western countries. Dangerous conditions evaluated by the psychiatric nurses and police rather than diagnosis made by the psychiatrists were related factors of involuntary admission. As it spent more time to admit involuntary patients, it was suggested that multidisciplinary professionals should be included in and educated for during the process of involuntary admission. PMID:26046529

Violent behavior by emergency department patients with an involuntary hold status.

PubMed

Dawson, Nancy L; Lachner, Christian; Vadeboncoeur, Tyler F; Maniaci, Michael J; Bosworth, Veronica; Rummans, Teresa A; Roy, Archana; Burton, M Caroline

2018-03-01

Violence against health care workers has been increasing. Health care workers in emergency departments (EDs) are highly vulnerable because they provide care for patients who may have mental illness, behavioral problems, or substance use disorders (alone or in combination) and who are often evaluated during an involuntary hold. Our objective was to identify factors that may be associated with violent behavior in ED patients during involuntary holds. Retrospective review of patients evaluated during an involuntary hold at a suburban acute care hospital ED from January 2014 through November 2015. Of 251 patients, 22 (9%) had violent incidents in the ED. Violent patients were more likely to have a urine drug screen positive for tricyclic antidepressants (18.2% vs 4.8%, P=0.03) and to present with substance misuse (68.2% vs 39.7%, P=0.01), specifically with marijuana (22.7% vs 9.6%, P=0.06) and alcohol (54.5% vs 24.9%, P=0.003). ED readmission rates were higher for violent patients (18.2% vs 3.9%, P=0.02). No significant difference was found between violent patients and nonviolent patients for sex, race, marital status, insurance status, medical or psychiatric condition, reason for involuntary hold, or length of stay. Violent behavior by patients evaluated during an involuntary hold in a suburban acute care hospital ED was associated with tricyclic antidepressant use, substance misuse, and higher ED readmission rates. Copyright © 2017 Elsevier Inc. All rights reserved.

Lasting improvements in left spatial neglect following a protocol combining neck-muscle vibration and voluntary arm movements: a case-study.

PubMed

Ceyte, Hadrien; Beis, Jean-Marie; Simon, Mathilde; Rémy, Ariane; Anxionnat, René; Paysant, Jean; Caudron, Sébastien

2018-01-22

Beyond promising experimental results of sensory passive stimulations in spatial cognition disorders, some questions still remain regarding interests of these stimulations during the daily activities in neglect. The aim of this case-study was to evaluate the effects of a protocol combining left neck-muscle vibration with daily simple movements, like arm pointing movements, on perceptivo-locomotor deficits in a left spatial neglect patient. Two neuropsychological tests, one subjective straight-ahead pointing (SSA) test and one wheelchair navigation test were carried out before the combination protocol, immediately after, 1 h later, and 24 h later. The results showed a reduction of neglect spatial bias following the protocol lasted at least 24 h in all the tests (except for the SSA test due to the unavailability of the pointing device). The range of improvements in the symptoms of spatial neglect suggests that this therapeutic intervention based on the combining neck-muscle vibration to voluntary arm movements could be a useful treatment for this condition. One of future investigation axes should be the development of a vibratory tool in order to facilitate the combining this proprioceptive stimulation to daily activities. Implications for rehabilitation Spatial neglect is a perplexing neuropsychological syndrome, affecting different domains of spatial cognition and impacting also the functional domain. The treatments based on neck-muscle vibration are simple to use, non-invasive and requires none active participation of patient. A therapeutic intervention based on the combining left neck-muscle vibration and voluntary arm movements in a left-spatial-neglect show a lasting reduction of symptoms especially in daily activities. The combination of treatments based on the Bottom-Up approach opens innovative perspectives in rehabilitation.

[Involuntary psychiatric care for inmates in France: Only for "dangerous" patients?

PubMed

Fovet, T; Bertrand, M; Horn, M; Si Mohammed, W; Dandelot, D; Dalle, M-C; Thomas, P; Amad, A

2017-11-27

The unités hospitalières spécialement aménagées (UHSA) are full-time inpatient psychiatric units for inmates in France. Their creation has been associated with several advances in access to psychiatric care for inmates in recent years. However, there is still only one means of involuntary hospitalization for prisoners in France: care by decision of a representative of the state (les soins sur décision d'un représentant de l'état [SDRE]). Interestingly, for SDRE to be recognized as legal by the French judge, the patient must be "a danger to himself or to the others". Thus, there is a major difference with involuntary hospitalization outside the prison, and there are specific criteria for involuntary psychiatric hospitalization for inmates in France. This situation questions the general framework of involuntary psychiatric care and is very inconsistent with French law. Indeed, the goal of the loi n o  94-43 du 18 janvier 1994 relating to public health and social protection is to ensure equivalent care for all patients, incarcerated or not. Copyright © 2017 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

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)

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.

Pilot study on quantitative assessment of muscle imbalance: differences of muscle synergies, equilibrium-point trajectories, and endpoint stiffness in normal and pathological upper-limb movements.

PubMed

Oku, Takanori; Uno, Kanna; Nishi, Tomoki; Kageyama, Masayuki; Phatiwuttipat, Pipatthana; Koba, Keitaro; Yamashita, Yuto; Murakami, Kenta; Uemura, Mitsunori; Hirai, Hiroaki; Miyazaki, Fumio; Naritomi, Hiroaki

2014-01-01

This paper proposes a novel method for assessment of muscle imbalance based on muscle synergy hypothesis and equilibrium point (EP) hypothesis of motor control. We explain in detail the method for extracting muscle synergies under the concept of agonist-antagonist (AA) muscle pairs and for estimating EP trajectories and endpoint stiffness of human upper limbs in a horizontal plane using an electromyogram. The results of applying this method to the reaching movement of one normal subject and one hemiplegic subject suggest that (1) muscle synergies (the balance among coactivation of AA muscle pairs), particularly the synergies that contributes to the angular directional kinematics of EP and the limb stiffness, are quite different between the normal subject and the hemiplegic subject; (2) the concomitant EP trajectory is also different between the normal and hemiplegic subjects, corresponding to the difference of muscle synergies; and (3) the endpoint (hand) stiffness ellipse of the hemiplegic subject becomes more elongated and orientation of the major axis rotates clockwise more than that of the normal subject. The level of motor impairment would be expected to be assessed from a comparison of these differences of muscle synergies, EP trajectories, and endpoint stiffness among normal and pathological subjects using the method.

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)

[Factors associated with involuntary hospital admissions in technology-dependent children].

PubMed

Okido, Aline Cristiane Cavicchioli; Pina, Juliana Coelho; Lima, Regina Aparecida Garcia

2016-02-01

To identify the factors associated with involuntary hospital admissions of technology-dependent children, in the municipality of Ribeirão Preto, São Paulo State, Brazil. A cross-sectional study, with a quantitative approach. After an active search, 124 children who qualified under the inclusion criteria, that is to say, children from birth to age 12, were identified. Data was collected in home visits to mothers or the people responsible for the children, through the application of a questionnaire. Analysis of the data followed the assumptions of the Generalized Linear Models technique. 102 technology-dependent children aged between 6 months and 12 years participated in the study, of whom 57% were male. The average number of involuntary hospital admissions in the previous year among the children studied was 0.71 (±1.29). In the final model the following variables were significantly associated with the outcome: age (OR=0.991; CI95%=0.985-0.997), and the number of devices (OR=0.387; CI95%=0.219-0.684), which were characterized as factors of protection and quantity of medications (OR=1.532; CI95%=1.297-1.810), representing a risk factor for involuntary hospital admissions in technology-dependent children. The results constitute input data for consideration of the process of care for technology-dependent children by supplying an explanatory model for involuntary hospital admissions for this client group.

32 CFR 634.38 - Involuntary extraction of bodily fluids in traffic cases.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Involuntary extraction of bodily fluids in traffic cases. 634.38 Section 634.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.38 Involuntary extraction of...

Contingent involuntary motoric inhibition: the involuntary inhibition of a motor response contingent on top-down goals.

PubMed

Anderson, Brian A; Folk, Charles L

2012-12-01

Effective motor control involves both the execution of appropriate responses and the inhibition of inappropriate responses that are evoked by response-associated stimuli. The inhibition of a motor response has traditionally been characterized as either a voluntary act of cognitive control or a low-level perceptual bias arising from processes such as inhibition of return and priming. Involuntary effects of top-down goals on motoric inhibition have been reported, but involve the perseveration of an inhibitory strategy. It is unknown whether the inhibition of a motor response can be selectively triggered by a goal-relevant stimulus, reflecting the automatic activation of a top-down inhibitory strategy. Here we show that irrelevant flankers that share the color of a no-go target elicit the inhibition of their associated motor response while other-colored flankers do not, even when participants have sufficient time to prepare for the upcoming target while ignoring the flankers. Our results demonstrate contingent involuntary motoric inhibition: motoric inhibition can be automatically triggered by a stimulus based on top-down goals.

The sigma-1 antagonist BMY-14802 inhibits L-DOPA-induced abnormal involuntary movements by a WAY-100635-sensitive mechanism

PubMed Central

Paquette, Melanie A.; Foley, Katherine; Brudney, Elizabeth G.; Meshul, Charles K.; Johnson, Steven W.; Berger, S. Paul

2010-01-01

Rationale Levodopa (L-DOPA), the gold standard treatment for Parkinson's disease (PD), eventually causes L-DOPA-induced dyskinesia (LID) in up to 80% of patients. In the 6-hydroxydopamine (6-OHDA) rat model of PD, L-DOPA induces a similar phenomenon, which has been termed abnormal involuntary movement (AIM). We previously demonstrated that BMY-14802 suppresses AIM expression in this model. Objectives Although BMY-14802 is widely used as a sigma-1 antagonist, it is also an agonist at serotonin (5-HT) 1A and adrenergic α-1 receptors. The current study was conducted to determine which of these mechanisms underlies BMY-14802's AIM-suppressing effect. This characterization included testing the 5-HT1A agonist buspirone and multiple sigma agents. When these studies implicated a 5-HT1A mechanism, we subsequently undertook a pharmacological reversal study, evaluating whether the 5-HT1A antagonist WAY-100635 counteracted BMY-14802's AIM-suppressing effects. Results Buspirone dose-dependently suppressed AIM, supporting past findings. However, no AIM-suppressing effects were produced by drugs with effects at sigma receptors, including BD-1047, finasteride, SM-21, DTG, trans-dehydroandrosterone (DHEA), carbetapentane, and opipramol. Finally, we show for the first time that the AIM-suppressing effect of BMY-14802 was dose-dependently prevented by WAY-100635 but not by the α-1 antagonist prazosin. Conclusions BMY-14802 exerts its AIM-suppressing effects via a 5-HT1A agonist mechanism, similar to buspirone. Other 5-HT1A agonists have failed clinical trials, possibly due to submicromolar affinity at other receptors, including D2, which may exacerbate PD symptoms. BMY-14802 is a promising candidate for clinical trials due to its extremely low affinity for the D2 receptor and lack of extrapyramidal effects during prior clinical trials for schizophrenia. PMID:19283364

Eyebrow ptosis after blowout fracture indicates impairment of trigeminal proprioceptive evocation that induces reflex contraction of the frontalis muscle.

PubMed

Ban, Ryokuya; Matsuo, Kiyoshi; Ban, Midori; Yuzuriha, Shunsuke

2013-01-01

The mixed levator and frontalis muscles lack the interior muscle spindles normally required to induce involuntary contraction of their slow-twitch fibers. To involuntarily move the eyelid and eyebrow, voluntary contraction of the levator nonskeletal fast-twitch muscle fibers stretches the mechanoreceptors in Müller's muscle to evoke trigeminal proprioception, which then induces reflex contraction of the levator and frontalis skeletal slow-twitch muscle fibers. The trigeminal proprioceptive nerve has a long intraorbital course from the mechanoreceptors in Müller's muscle to the superior orbital fissure. Since external force to the globe may cause impairment of trigeminal proprioceptive evocation, we confirmed how unilateral blowout fracture due to a hydraulic mechanism affects ipsilateral eyebrow movement as compared with unilateral zygomatic fracture. In 16 unilateral blowout fracture patients, eyebrow heights were measured on noninjured and injured sides in primary and 60° upward gaze and statistically compared. Eyebrow heights were also measured in primary gaze in 24 unilateral zygomatic fracture patients and statistically compared. In the blowout fracture patients, eyebrow heights on the injured side were significantly smaller than on the noninjured side in both gaze. In the zygomatic fracture patients, eyebrow heights on the injured side were significantly larger than on the noninjured side in primary gaze. Since 60° upward gaze did not recover the eyebrow ptosis observed in primary gaze in blowout fracture patients, such ptosis indicated impairment of trigeminal proprioceptive evocation and the presence of a hydraulic mechanism that may require ophthalmic examination.

Relationship between function of masticatory muscle in mouse and properties of muscle fibers.

PubMed

Abe, Shinichi; Hiroki, Emi; Iwanuma, Osamu; Sakiyama, Koji; Shirakura, Yoshitaka; Hirose, Daiki; Shimoo, Yoshiaki; Suzuki, Masashi; Ikari, Yasutoyo; Kikuchi, Ryusuke; Ide, Yoshinobu; Yoshinari, Masao

2008-05-01

Mammals exhibit marked morphological differences in the muscles surrounding the jaw bone due to differences in eating habits. Furthermore, the myofiber properties of the muscles differ with function. Since the muscles in the oral region have various functions such as eating, swallowing, and speech, it is believed that the functional role of each muscle differs. Therefore, to clarify the functional role of each masticatory muscle, the myofiber properties of the adult mouse masticatory muscles were investigated at the transcriptional level. Expression of MyHC-2b with a fast contraction rate and strong force was frequently noted in the temporal and masseter muscles. This suggests that the temporal and masseter muscles are closely involved in rapid antero-posterior masticatory movement, which is characteristic in mice. Furthermore, expression of MyHC-1 with a low contraction rate and weak continuous force was frequently detected in the lateral pterygoid muscle. This suggests that, in contrast to other masticatory muscles, mouse lateral pterygoid muscle is not involved in fast masticatory movement, but is involved in functions requiring continuous force such as retention of jaw position. This study revealed that muscles with different roles function comprehensively during complicated masticatory movement.

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…

Association between involuntary smoking and salivary markers related to periodontitis: a 2-year longitudinal study.

PubMed

Nishida, Nobuko; Yamamoto, Yumiko; Tanaka, Muneo; Kataoka, Kosuke; Kuboniwa, Masae; Nakayama, Kunio; Morimoto, Kanehisa; Shizukuishi, Satoshi

2008-12-01

Insufficient data exist regarding the longitudinal influence of involuntary smoking on periodontitis progression. This study examined the relationship between involuntary smoking and periodontitis progression and the effects of involuntary smoking on salivary inflammatory and microbiologic markers related to periodontitis. Participants were recruited during annual health checkups in 2003 and 2005. In 2005, 200 of 273 (73%) Japanese employees examined at baseline underwent periodontal measurements, including clinical attachment level (CAL) and probing depth (PD). Periodontitis progression was identified when a subject displayed one or more teeth with an increase > or = 2.0 mm in CAL and PD during the 2 years. Salivary marker levels, including cotinine, were determined by enzyme assay, including enzyme-linked immunosorbent assay. The proportions of six periodontal pathogens in saliva were assessed using real-time polymerase chain reaction methodology. Based on receiver-operating characteristic analysis, non-, involuntary, and active smokers were defined as subjects exhibiting salivary cotinine levels of 0, 1 to 7, and > or = 8 ng/ml, respectively. By simple logistic regression analysis, age, alcohol consumption, smoking, breakfast habits, and working hours were related to the risk for significant periodontitis progression. Multiple logistic regression analysis revealed significantly higher periodontitis odds ratios (OR) in involuntary (OR = 2.23; 95% confidence interval [CI]: 1.03 to 4.83) and active (OR = 2.27; 95% CI: 1.02 to 5.04) smokers relative to non-smokers following adjustment for covariates. Levels of salivary markers, including albumin, aspartate aminotransferase, and lactoferrin, were significantly elevated in involuntary smokers relative to non-smokers. In contrast, the percentages of periodontal pathogens did not differ between the smoking groups, with the exception of Prevotella nigrescens, which displayed significantly lower levels in involuntary

The association of visually-assessed quality of movement during jump-landing with ankle dorsiflexion range-of-motion and hip abductor muscle strength among healthy female athletes.

PubMed

Rabin, Alon; Einstein, Ofira; Kozol, Zvi

2018-05-01

To explore the association between ankle dorsiflexion (DF) range of motion (ROM), and hip abductor muscle strength, to visually-assessed quality of movement during jump-landing. Cross-sectional. Gymnasium of participating teams. 37 female volleyball players. Quality of movement in the frontal-plane, sagittal-plane, and overall (both planes) was visually rated as "good/moderate" or "poor". Weight-bearing Ankle DF ROM and hip abductor muscle strength were compared between participants with differing quality of movement. Weight-bearing DF ROM on both sides was decreased among participants with "poor" sagittal-plane quality of movement (dominant side: 50.8° versus 43.6°, P = .02; non-dominant side: 54.6° versus 45.9°, P = .01), as well as among participants with an overall "poor" quality of movement (dominant side: 51.8° versus 44.0°, P < .01; non-dominant side: 56.5° versus 45.1°, P < .01). Weight-bearing ankle DF on the non-dominant side was decreased among participants with a "poor" frontal-plane quality of movement (53.9° versus 46.0°, P = .02). No differences in hip abductor muscle strength were noted between participants with differing quality of movement. Visual assessment of jump-landing can detect differences in quality of movement that are associated with ankle DF ROM. Clinicians observing a poor quality of movement may wish to assess ankle DF ROM. Copyright © 2018 Elsevier Ltd. All rights reserved.

Movement patterns of peak-dose levodopa-induced dyskinesias in patients with Parkinson's disease.

PubMed

Gour, Jackie; Edwards, Roderick; Lemieux, Sarah; Ghassemi, Mehrdad; Jog, Mandar; Duval, Christian

2007-09-14

The present study characterized involuntary movements associated with levodopa-induced dyskinesias (LID) in patients with Parkinson's disease. We used amplitude, proportional energy, frequency dispersion and sample entropy to determine whether LID movement patterns are truly random, as clinical description seems to suggest, or possess some underlying pattern that is not visible to the naked eye. LID was captured using a magnetic tracker system, which provided 3D rendering of whole-body LID. Patients were instructed to maintain a standing position, with arms extended in front of them. We compared the measurements of the dyskinetic PD group (DPD) with 10 patients without dyskinesias (NDPD) and 10 control subjects. In comparison to the other two groups, movement patterns from the DPD group had significantly higher amplitude, confirming the presence of dyskinesias. In addition, higher frequency components in the power spectrum of velocity were detected, suggestive of higher velocity in LID movement. Furthermore, there was a concentration in narrow frequency bands, which suggested stable oscillatory activity. Finally, sample entropy revealed more regularity in the DPD group. Although not statistically significant, we found that the amplitude from the NDPD group had a tendency to be smaller than those of controls. As well, the spectra were often more dispersed for the NDPD group. In conclusion, the present results suggest that LID cannot be considered as purely random movement since they possess some deterministic pattern of motion. This may provide a way for patients to adapt to these involuntary movements while performing voluntary motor acts.

Involuntary psychiatric hospitalisation, stigma stress and recovery: a 2-year study.

PubMed

Xu, Z; Lay, B; Oexle, N; Drack, T; Bleiker, M; Lengler, S; Blank, C; Müller, M; Mayer, B; Rössler, W; Rüsch, N

2018-01-31

Compulsory admission can be experienced as devaluing and stigmatising by people with mental illness. Emotional reactions to involuntary hospitalisation and stigma-related stress may affect recovery, but longitudinal data are lacking. We, therefore, examined the impact of stigma-related emotional reactions and stigma stress on recovery over a 2-year period. Shame and self-contempt as emotional reactions to involuntary hospitalisation, stigma stress, self-stigma and empowerment, as well as recovery were assessed among 186 individuals with serious mental illness and a history of recent involuntary hospitalisation. More shame, self-contempt and stigma stress at baseline were correlated with increased self-stigma and reduced empowerment after 1 year. More stigma stress at baseline was associated with poor recovery after 2 years. In a longitudinal path analysis more stigma stress at baseline predicted poorer recovery after 2 years, mediated by decreased empowerment after 1 year, controlling for age, gender, symptoms and recovery at baseline. Stigma stress may have a lasting detrimental effect on recovery among people with mental illness and a history of involuntary hospitalisation. Anti-stigma interventions that reduce stigma stress and programs that enhance empowerment could improve recovery. Future research should test the effect of such interventions on recovery.

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

PubMed Central

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

2014-01-01

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. PMID:24860176

Effects of multidimensional pelvic floor muscle training in healthy young women.

PubMed

Talasz, Helena; Kalchschmid, Elisabeth; Kofler, Markus; Lechleitner, Monika

2012-03-01

Cross-sectional and interventional study to assess pelvic floor muscle (PFM) function in healthy young nulliparous women and to determine the effects of a 3-month PFM training program with emphasis on co-contraction of PFM and anterolateral abdominal muscles and on correctly performed coughing patterns. PFM function was assessed by digital vaginal palpation in 40 volunteers and graded according to the 6-point Oxford grading scale. The PFM training program was comprised theoretical instruction, as well as verbal feedback during hands-on instruction and repeated training sessions focussing on strengthening PFM and anterolateral abdominal muscle co-contraction during forced expiration and coughing. At baseline, 30 women (75%) were able to perform normal PFM contractions at rest (Oxford scale score ≥ 3); only 4 of them (10%) presented additional involuntary PFM contractions before and during coughing. The remaining 10 women (25%) were unable to perform voluntary or involuntary PFM contractions. Mean Oxford scale score in the whole group was 3.3 ± 1.7. After completing the PFM training program, 29 women (72.5%) performed cough-related PFM contractions and group mean Oxford scale score increased significantly to 4.2 ± 1.0. The study shows that PFM dysfunction may be detected even in healthy young women. Multidimensional training, however, may significantly improve PFM function.

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.

47 CFR 101.75 - Involuntary relocation procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... adjustments, determine comparability, and ensure a seamless handoff. (d) Twelve-month trial period. If, within... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers, Modifications, Conditions and Forfeitures § 101.75 Involuntary relocation procedures. (a) If no agreement is reached during the...

47 CFR 101.75 - Involuntary relocation procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... adjustments, determine comparability, and ensure a seamless handoff. (d) Twelve-month trial period. If, within... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers, Modifications, Conditions and Forfeitures § 101.75 Involuntary relocation procedures. (a) If no agreement is reached during the...

47 CFR 101.75 - Involuntary relocation procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... adjustments, determine comparability, and ensure a seamless handoff. (d) Twelve-month trial period. If, within... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers, Modifications, Conditions and Forfeitures § 101.75 Involuntary relocation procedures. (a) If no agreement is reached during the...

47 CFR 101.75 - Involuntary relocation procedures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... adjustments, determine comparability, and ensure a seamless handoff. (d) Twelve-month trial period. If, within... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses License Transfers, Modifications, Conditions and Forfeitures § 101.75 Involuntary relocation procedures. (a) If no agreement is reached during the...

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…

Scapular kinematic and shoulder muscle activity alterations after serratus anterior muscle fatigue.

PubMed

Umehara, Jun; Kusano, Ken; Nakamura, Masatoshi; Morishita, Katsuyuki; Nishishita, Satoru; Tanaka, Hiroki; Shimizu, Itsuroh; Ichihashi, Noriaki

2018-02-23

Although the serratus anterior muscle has an important role in scapular movement, no study to date has investigated the effect of serratus anterior fatigue on scapular kinematics and shoulder muscle activity. The purpose of this study was to clarify the effect of serratus anterior fatigue on scapular movement and shoulder muscle activity. The study participants were 16 healthy men. Electrical muscle stimulation was used to fatigue the serratus anterior muscle. Shoulder muscle strength and endurance, scapular movement, and muscle activity were measured before and after the fatigue task. The muscle activity of the serratus anterior, upper and lower trapezius, anterior and middle deltoid, and infraspinatus muscles was recorded, and the median power frequency of these muscles was calculated to examine the degree of muscle fatigue. The muscle endurance and median power frequency of the serratus anterior muscle decreased after the fatigue tasks, whereas the muscle activities of the serratus anterior, upper trapezius, and infraspinatus muscles increased. External rotation of the scapula at the shoulder elevated position increased after the fatigue task. Selective serratus anterior fatigue due to electric muscle stimulation decreased the serratus anterior endurance at the flexed shoulder position. Furthermore, the muscle activities of the serratus anterior, upper trapezius, and infraspinatus increased and the scapular external rotation was greater after serratus anterior fatigue. These results suggest that the rotator cuff and scapular muscle compensated to avoid the increase in internal rotation of the scapula caused by the dysfunction of the serratus anterior muscle. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

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.

From the motor cortex to the movement and back again.

PubMed

Teka, Wondimu W; Hamade, Khaldoun C; Barnett, William H; Kim, Taegyo; Markin, Sergey N; Rybak, Ilya A; Molkov, Yaroslav I

2017-01-01

The motor cortex controls motor behaviors by generating movement-specific signals and transmitting them through spinal cord circuits and motoneurons to the muscles. Precise and well-coordinated muscle activation patterns are necessary for accurate movement execution. Therefore, the activity of cortical neurons should correlate with movement parameters. To investigate the specifics of such correlations among activities of the motor cortex, spinal cord network and muscles, we developed a model for neural control of goal-directed reaching movements that simulates the entire pathway from the motor cortex through spinal cord circuits to the muscles controlling arm movements. In this model, the arm consists of two joints (shoulder and elbow), whose movements are actuated by six muscles (4 single-joint and 2 double-joint flexors and extensors). The muscles provide afferent feedback to the spinal cord circuits. Cortical neurons are defined as cortical "controllers" that solve an inverse problem based on a proposed straight-line trajectory to a target position and a predefined bell-shaped velocity profile. Thus, the controller generates a motor program that produces a task-specific activation of low-level spinal circuits that in turn induce the muscle activation realizing the intended reaching movement. Using the model, we describe the mechanisms of correlation between cortical and motoneuronal activities and movement direction and other movement parameters. We show that the directional modulation of neuronal activity in the motor cortex and the spinal cord may result from direction-specific dynamics of muscle lengths. Our model suggests that directional modulation first emerges at the level of muscle forces, augments at the motoneuron level, and further increases at the level of the motor cortex due to the dependence of frictional forces in the joints, contractility of the muscles and afferent feedback on muscle lengths and/or velocities.

Interpretations of legal criteria for involuntary psychiatric admission: a qualitative analysis.

PubMed

Feiring, Eli; Ugstad, Kristian N

2014-10-25

The use of involuntary admission in psychiatry may be necessary to enable treatment and prevent harm, yet remains controversial. Mental health laws in high-income countries typically permit coercive treatment of persons with mental disorders to restore health or prevent future harm. Criteria intended to regulate practice leave scope for discretion. The values and beliefs of staff may become a determinating factor for decisions. Previous research has only to a limited degree addressed how legal criteria for involuntary psychiatric admission are interpreted by clinical decision-makers. We examined clinicians' interpretations of criteria for involuntary admission under the Norwegian Mental Health Care Act. This act applies a status approach, whereby involuntary admission can be used at the presence of mental disorder and need for treatment or perceived risk to the patient or others. Further, best interest assessments carry a large justificatory burden and open for a range of extra-legislative factors to be considered. Deductive thematic analysis was used. Three ideal types of attitudes-to-coercion were developed, denoted paternalistic, deliberative and interpretive. Semi-structured, in-depth interviews with 10 Norwegian clinicians with experience from admissions to psychiatric care were carried out. Data was fit into the preconceived analytical frame. We hypothesised that the data would mirror the recent shift from paternalism towards a more human rights focused approach in modern mental health care. The paternalistic perspective was, however, clearly expressed in the data. Involuntary admission was considered to be in the patient's best interest, and patients suffering from serious mental disorder were assumed to lack decision-making capacity. In addition to assessment of need, outcome effectiveness and risk of harm, extra-legislative factors such as patients' functioning, experience, resistance, networks, and follow-up options were told to influence decisions

Effects of pushing height on trunk posture and trunk muscle activity when a cart suddenly starts or stops moving.

PubMed

Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

2012-01-01

Unexpected sudden (un)loading of the trunk may induce inadequate responses of trunk muscles and uncontrolled trunk motion. These unexpected perturbations may occur in pushing tasks, when the cart suddenly starts moving (unloading) or is blocked by an obstacle (loading). In pushing, handle height affects the user's working posture, which may influence trunk muscle activity and trunk movement in response to the perturbation. Eleven healthy male subjects pushed a 200 kg cart with handles at shoulder and hip height in a start condition (sudden release of brakes) and a stop condition (bumping into an obstacle). Before the perturbation, the baseline of the trunk inclination, internal moment and trunk extensor muscle activity were significantly higher when pushing at hip height than at shoulder height. After the perturbation, the changes in trunk inclination and internal moment were significantly larger when pushing at shoulder height than at hip height in both conditions. The opposite directions of changes in trunk inclination and internal moment suggest that the unexpected perturbations caused uncontrolled trunk motion. Pushing at shoulder height may impose a high risk of low-back injury due to the low trunk stiffness and large involuntary trunk motion occurring after carts suddenly move or stop.

47 CFR 101.91 - Involuntary relocation procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Policies Governing Fixed Service Relocation from the 18.58-19.30 Ghz Band § 101.91 Involuntary relocation procedures. (a) If no agreement is... Commission's rules. FSS licensees are obligated to pay to relocate only the specific microwave links from...

47 CFR 101.91 - Involuntary relocation procedures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Policies Governing Fixed Service Relocation from the 18.58-19.30 Ghz Band § 101.91 Involuntary relocation procedures. (a) If no agreement is... Commission's rules. FSS licensees are obligated to pay to relocate only the specific microwave links from...

47 CFR 101.91 - Involuntary relocation procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Policies Governing Fixed Service Relocation from the 18.58-19.30 Ghz Band § 101.91 Involuntary relocation procedures. (a) If no agreement is... Commission's rules. FSS licensees are obligated to pay to relocate only the specific microwave links from...

47 CFR 101.91 - Involuntary relocation procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Policies Governing Fixed Service Relocation from the 18.58-19.30 Ghz Band § 101.91 Involuntary relocation procedures. (a) If no agreement is... Commission's rules. FSS licensees are obligated to pay to relocate only the specific microwave links from...

[Involuntary treatment of mental patients in the community: legal and ethical dilemmas].

PubMed

Mitrossili, M

2014-01-01

This article focuses on the measure of involuntary treatment of mental patients in the community, not only with regard to human rights and more specifically those of persons with mental disorders, but also with regard to ethics and deontology in mental healthcare delivery service. In this light, the important role of informed consent in psychiatry with regard to the psychiatric act is examined. Informed consent of mental patients in treatment when they are in need of voluntary or involuntary hospitalization is further examined, while emphasis is being put on the case of involuntary treatment. The Convention for Human Rights and Biomedicine (Convention of Οviedo), the European Convention of Human Rights, other documents of International Organizations (UN) and specialized national legislation (A. 2071/1992, Chapter vi, Greek law) constitute basic reference and interpretation points. The examination of consent and the demarcation of the exceptions are important issues that need to be approached. More particularly, our interest lies with the article 7 of the Convention for Human Rights and Biomedicine, which specifically refers to the protection of person who suffers from a mental disorder. The opinion that informed consent in psychiatric treatment and involuntary treatment are concepts and processes which are distinct but not always mutually exclusive is enhanced. In any case, involuntary treatment causes major dilemmas as far as informed consent in the psychiatric act is concerned, as it raises issues that affect the autonomy of the person. Today, however, there are many factors which influence public politics towards the adoption of the measure of involuntary treatment within the community. How is it that this paradoxical link is legitimized and justified: involuntary treatment and community? The enactment of the above mentioned measure in many European and North American countries has created new paths in the practice of contemporary psychiatry. Nonetheless, it

[Mental capacity and capacity to consent: multicentric study in a involuntary psychiatric hospitalized patients sample].

PubMed

Carabellese, Felice; Mandarelli, Gabriele; La Tegola, Donatella; Parmigiani, Giovanna; Ferracuti, Stefano; Quartesan, Roberto; Bellomo, Antonello; Catanesi, Roberto

2017-01-01

The purpose of this longitudinal observational study is to evaluate the course and impact of clinical, social, and behavioral variables on the involuntary readmission of psychiatric patients, during a 6-months follow-up after discharge from a prior involuntary hospitalization. N=131 involuntarily committed psychiatric patients were enrolled in three university hospitals (Bari n=57; Perugia n=42; Rome n=32). At the first assessment cognitive functioning (MMSE), psychiatric symptoms severity (BPRS-E), capacity to consent to treatment (MacCAT-T) as well as principal socio-demographic and clinical variables were collected. At 6-months follow-up, we collected data concerning involuntary psychiatric readmissions, pharmacotherapy adherence, new deliberate self-harm or harm to others as well as having been legally prosecuted. N=120 patients were reevaluated at follow-up (M=188 days, SD=12.6); among these n=15 (12.5%) have had a new involuntary psychiatric admission due to an acute mental disorder. Re-hospitalized patients showed higher rates of harm to others (p<0.05) and legal prosecution (p<0.05); there was moreover a trend toward higher pharmacological dropout rates in involuntarily rehospitalized patients. We found no differences between the two groups in baseline psychiatric symptoms severity and cognitive functioning, whereas involuntary re-hospitalization was associated with more frequent involuntary hospitalization during last year (p<0.05) and higher MacCAT-T reasoning (p<0.05). Involuntary psychiatric readmission rates proved to be poorly associated with clinical features assessed during previous hospitalization. Our data suggest that social and legal factors, including those connected to patients' dangerousness, could play a role also in a civil commitment system based solely on the need for treatment.

[Quality of involuntary hospital administration in Switzerland].

PubMed

Jäger, Matthias; Ospelt, Isabelle; Kawohl, Wolfram; Theodoridou, Anastasia; Rössler, Wulf; Hoff, Paul

2014-05-21

This study aims at investigating the formal and content-related quality of medical certificates directing compulsory hospital admissions before the scheduled alteration of the Swiss civil legislation in January 2013. A comparison between physicians with different professional backgrounds concerning certificates and patients was conducted. Retrospective investigation of medical records of involuntary inpatients at the University Hospital of Psychiatry in Zurich during a period of six months (N=489). Considerable deficits concerning formal and particularly content-related aspects of the certificates were found. Psychiatrists issued certificates of the highest quality followed by emergency physicians, hospital doctors and general practitioners. Patients differed with respect to several sociodemographic and clinical variables. The quality of certificates directing involuntary hospital admission has to be improved considering the impact on the individual concerned. The consequences of the new legislation on the quality of the admission practices should be inquired in order to improve professional training on the issue.

Towards NIRS-based hand movement recognition.

PubMed

Paleari, Marco; Luciani, Riccardo; Ariano, Paolo

2017-07-01

This work reports on preliminary results about on hand movement recognition with Near InfraRed Spectroscopy (NIRS) and surface ElectroMyoGraphy (sEMG). Either basing on physical contact (touchscreens, data-gloves, etc.), vision techniques (Microsoft Kinect, Sony PlayStation Move, etc.), or other modalities, hand movement recognition is a pervasive function in today environment and it is at the base of many gaming, social, and medical applications. Albeit, in recent years, the use of muscle information extracted by sEMG has spread out from the medical applications to contaminate the consumer world, this technique still falls short when dealing with movements of the hand. We tested NIRS as a technique to get another point of view on the muscle phenomena and proved that, within a specific movements selection, NIRS can be used to recognize movements and return information regarding muscles at different depths. Furthermore, we propose here three different multimodal movement recognition approaches and compare their performances.

Muscle co-contraction patterns in robot-mediated force field learning to guide specific muscle group training.

PubMed

Pizzamiglio, Sara; Desowska, Adela; Shojaii, Pegah; Taga, Myriam; Turner, Duncan L

2017-01-01

Muscle co-contraction is a strategy of increasing movement accuracy and stability employed in dealing with force perturbation of movement. It is often seen in neuropathological populations. The direction of movement influences the pattern of co-contraction, but not all movements are easily achievable for populations with motor deficits. Manipulating the direction of the force instead, may be a promising rehabilitation protocol to train movement with use of a co-contraction reduction strategy. Force field learning paradigms provide a well described procedure to evoke and test muscle co-contraction. The aim of this study was to test the muscle co-contraction pattern in a wide range of arm muscles in different force-field directions utilising a robot-mediated force field learning paradigm of motor adaptation. Forty-two participants volunteered to participate in a study utilising robot-mediated force field motor adaptation paradigm with a clockwise or counter-clockwise force field. Kinematics and surface electromyography (EMG) of eight arm muscles were measured. Both muscle activation and co-contraction was earlier and stronger in flexors in the clockwise condition and in extensors in the counter-clockwise condition. Manipulating the force field direction leads to changes in the pattern of muscle co-contraction.

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

PubMed

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

2015-01-01

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. 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. 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). 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.

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

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…

In response to community violence: coping strategies and involuntary stress responses among Latino adolescents.

PubMed

Epstein-Ngo, Quyen; Maurizi, Laura K; Bregman, Allyson; Ceballo, Rosario

2013-01-01

Among poor, urban adolescents, high rates of community violence are a pressing public health concern. This study relies on a contextual framework of stress and coping to investigate how coping strategies and involuntary stress responses may both mediate and moderate the relation between exposure to community violence and psychological well-being. Our sample consists of 223 ninth grade Latino adolescents from poor, urban families. In response to community violence, these adolescents reported using an array of coping strategies as well as experiencing a number of involuntary stress responses; the most frequent coping responses were turning to religion and seeking social support. Hierarchical regression analyses demonstrated that involuntary stress responses mediated the relations between both witnessing or being victimized by violence and poorer psychological functioning, while coping strategies moderated these relations. These findings suggest that the negative psychological effects of exposure to community violence may, in part, be explained by involuntary stress responses, while religious-based coping may serve as a protective factor.

Eyebrow Ptosis After Blowout Fracture Indicates Impairment of Trigeminal Proprioceptive Evocation That Induces Reflex Contraction of the Frontalis Muscle

PubMed Central

Ban, Ryokuya; Matsuo, Kiyoshi; Ban, Midori; Yuzuriha, Shunsuke

2013-01-01

Objective: The mixed levator and frontalis muscles lack the interior muscle spindles normally required to induce involuntary contraction of their slow-twitch fibers. To involuntarily move the eyelid and eyebrow, voluntary contraction of the levator nonskeletal fast-twitch muscle fibers stretches the mechanoreceptors in Müller's muscle to evoke trigeminal proprioception, which then induces reflex contraction of the levator and frontalis skeletal slow-twitch muscle fibers. The trigeminal proprioceptive nerve has a long intraorbital course from the mechanoreceptors in Müller's muscle to the superior orbital fissure. Since external force to the globe may cause impairment of trigeminal proprioceptive evocation, we confirmed how unilateral blowout fracture due to a hydraulic mechanism affects ipsilateral eyebrow movement as compared with unilateral zygomatic fracture. Methods: In 16 unilateral blowout fracture patients, eyebrow heights were measured on noninjured and injured sides in primary and 60° upward gaze and statistically compared. Eyebrow heights were also measured in primary gaze in 24 unilateral zygomatic fracture patients and statistically compared. Results: In the blowout fracture patients, eyebrow heights on the injured side were significantly smaller than on the noninjured side in both gaze. In the zygomatic fracture patients, eyebrow heights on the injured side were significantly larger than on the noninjured side in primary gaze. Conclusion: Since 60° upward gaze did not recover the eyebrow ptosis observed in primary gaze in blowout fracture patients, such ptosis indicated impairment of trigeminal proprioceptive evocation and the presence of a hydraulic mechanism that may require ophthalmic examination. PMID:23814636

How involuntary commitment impacts on the burden of care of the family.

PubMed

Hallam, Larissa

2007-08-01

Little research has examined how, or if, involuntary commitment has impacted on the burden experienced by the family. This paper reports a qualitative study which explored how involuntary commitment under the Mental Health Act (MHA) 2000 in Queensland, Australia impacted on families of people with mental illness. Family members of a person with a mental illness, under involuntary commitment at the time or in the previous 12 months, participated in focus groups. Thematic analysis was used to determine the themes. It was apparent from the views of the family that the use of the involuntary commitment was influenced greatly by the pressures experienced by the mental health services (MHS). The MHA did little to assist the family in gaining access to MHS. It was not until after the family made repeated attempts that they were taken seriously. Often the family had few options other than to use deceit and threats to obtain the necessary treatment required. In view of this, the inherit nature of what involuntary commitment implies for persons under it, such as refusing treatment and management difficulties, indicates the family with such an individual experience more hardship in trying to obtain assistance for that person. Thus, the MHA in Queensland has not met its goals of increasing access to MHS. Family members perceive that they were not being listened to and their concerns were not acted upon. The current culture of the MHS appears to serve, to a large degree, to estrange the family from the consumer making relationships difficult and time-consuming to repair. The mental health profession is urged to consider the culture within their workplace and move towards constructive involvement of the family.

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.

Involuntary admission may support treatment outcome and motivation in patients receiving assertive community treatment.

PubMed

Kortrijk, Hans Erik; Staring, A B P; van Baars, A W B; Mulder, C L

2010-02-01

Patients with severe mental illness who are treated in assertive community treatment (ACT) teams are sometimes involuntarily admitted when they are dangerous to themselves or others, and are not motivated for treatment. However, the consequences of involuntary admission in terms of psychosocial outcome and treatment motivation are largely unknown. We hypothesized that involuntary admission would improve psychosocial outcome and not adversely affect their treatment motivation. In the context of routine 6-monthly outcome monitoring in the period January 2003-March 2008, we used the Health of the Nation Outcome Scales (HoNOS) and a motivation-for-treatment scale to assess 260 severely mentally ill patients at risk for involuntary admission. Mixed models with repeated measures were used for data analyses. During the observation period, 77 patients (30%) were involuntarily admitted. Relative to patients who were not involuntarily admitted, these patients improved significantly in HoNOS total scores (F = 17,815, df = 1, p < 0.001) and in motivation for treatment (F = 28.139, df = 1, p < 0.001). Patients who were not involuntarily admitted had better HoNOS and motivation scores at baseline, but did not improve. Involuntary admission in the context of ACT was associated with improvements in psychosocial outcome and motivation for treatment. There are no indications that involuntary admission leads to deterioration in psychosocial outcome or worsening of motivation for treatment.

Differential Impact of Involuntary Job Loss on Physical Disability Among Older Workers Does Predisposition Matter?

PubMed Central

Gallo, William T.; Brand, Jennie E.; Teng, Hsun-Mei; Leo-Summers, Linda; Byers, Amy L.

2009-01-01

Older workers' share of involuntary job losses in the United States has grown fairly consistently in recent decades, prompting greater interest in the health consequences of involuntary unemployment among individuals nearing retirement. In this study, the authors applied the multifactorial model of geriatric health to investigate whether late-career involuntary job loss was associated with subsequent physical disability and whether the effect of involuntary job loss on physical disability varied by predisposition. Using data from the first four waves (1992 to 1998) of the Health and Retirement Survey, the authors measured predisposition with individual risk factors for functional disability and indices of aggregate risk. The results of gender-specific models fit with generalized estimating equations revealed that unmarried women and those with low predisplacement incomes had heightened risk for subsequent functional disability. No differential effects of job loss were found for men. PMID:19924265

Public attitudes towards involuntary admission and treatment by mental health services in Norway.

PubMed

Joa, Inge; Hustoft, Kjetil; Anda, Liss Gøril; Brønnick, Kolbjørn; Nielssen, Olav; Johannessen, Jan Olav; Langeveld, Johannes H

The role of compulsory treatment of serious mental disorders has been the topic of ongoing public debate involving among others mental health professionals, service providers, service user advocates, relatives of service users, media commentators and politicians. However, relatively little is known about general public attitudes towards involuntary admission and compulsory treatment of people with various mental disorders. This article examines the attitudes in a representative sample of Norway's population towards the use of involuntary admission and treatment, and under which circumstances does the general public consider compulsory treatment to be justified in the Norwegian mental health care services. Data were collected from a representative sample of the population in Norway aged 18 and older. The sample was stratified for gender, geographical region and age distribution (n=2001). The survey was performed in the months of May 2009 (n=1000) and May 2011 (n=1001), using Computer Assisted Telephone Interviews (CATI) by an independent polling company. All respondents were provided a general definition of coercive intervention before the interview was conducted. Univariate descriptions and bivariate analyses were performed by means of cross-tabulation, analysis of variance (one-way ANOVA) and comparing of group of means. Cohen's d was used as the measure for effect size. Between 87% and 97% of those surveyed expressed strong or partial agreement with the use of involuntary admissions or compulsory treatment related to specified cases and situations. The majority of interviewees (56%) expressed the opinion that overall, current levels are acceptable. A further, 34% were of the opinion that current levels are too low, while only 9.9% of respondents supported a reduction in the level of involuntary treatment. Lower levels of education were associated with a more positive attitude towards involuntary admission and treatment. There was stronger support for admission to

Hypoglossal-facial nerve reconstruction using a Y-tube-conduit reduces aberrant synkinetic movements of the orbicularis oculi and vibrissal muscles in rats.

PubMed

Kaya, Yasemin; Ozsoy, Umut; Turhan, Murat; Angelov, Doychin N; Sarikcioglu, Levent

2014-01-01

The facial nerve is the most frequently damaged nerve in head and neck trauma. Patients undergoing facial nerve reconstruction often complain about disturbing abnormal synkinetic movements of the facial muscles (mass movements, synkinesis) which are thought to result from misguided collateral branching of regenerating motor axons and reinnervation of inappropriate muscles. Here, we examined whether use of an aorta Y-tube conduit during reconstructive surgery after facial nerve injury reduces synkinesis of orbicularis oris (blink reflex) and vibrissal (whisking) musculature. The abdominal aorta plus its bifurcation was harvested (N = 12) for Y-tube conduits. Animal groups comprised intact animals (Group 1), those receiving hypoglossal-facial nerve end-to-end coaptation alone (HFA; Group 2), and those receiving hypoglossal-facial nerve reconstruction using a Y-tube (HFA-Y-tube, Group 3). Videotape motion analysis at 4 months showed that HFA-Y-tube group showed a reduced synkinesis of eyelid and whisker movements compared to HFA alone.

Hypoglossal-Facial Nerve Reconstruction Using a Y-Tube-Conduit Reduces Aberrant Synkinetic Movements of the Orbicularis Oculi and Vibrissal Muscles in Rats

PubMed Central

Kaya, Yasemin; Ozsoy, Umut; Turhan, Murat; Angelov, Doychin N.; Sarikcioglu, Levent

2014-01-01

The facial nerve is the most frequently damaged nerve in head and neck trauma. Patients undergoing facial nerve reconstruction often complain about disturbing abnormal synkinetic movements of the facial muscles (mass movements, synkinesis) which are thought to result from misguided collateral branching of regenerating motor axons and reinnervation of inappropriate muscles. Here, we examined whether use of an aorta Y-tube conduit during reconstructive surgery after facial nerve injury reduces synkinesis of orbicularis oris (blink reflex) and vibrissal (whisking) musculature. The abdominal aorta plus its bifurcation was harvested (N = 12) for Y-tube conduits. Animal groups comprised intact animals (Group 1), those receiving hypoglossal-facial nerve end-to-end coaptation alone (HFA; Group 2), and those receiving hypoglossal-facial nerve reconstruction using a Y-tube (HFA-Y-tube, Group 3). Videotape motion analysis at 4 months showed that HFA-Y-tube group showed a reduced synkinesis of eyelid and whisker movements compared to HFA alone. PMID:25574468

Increased long-latency reflex activity as a sufficient explanation for childhood hypertonic dystonia: a neuromorphic emulation study

NASA Astrophysics Data System (ADS)

Sohn, Won J.; Niu, Chuanxin M.; Sanger, Terence D.

2015-06-01

Objective. Childhood dystonia is a movement disorder that interferes with daily movements and can have a devastating effect on quality of life for children and their families. Although injury to basal ganglia is associated with dystonia, the neurophysiological mechanisms leading to the clinical manifestations of dystonia are not understood. Previous work suggested that long-latency stretch reflex (LLSR) is hyperactive in children with hypertonia due to secondary dystonia. We hypothesize that abnormal activity in motor cortices may cause an increase in the LLSR leading to hypertonia. Approach. We modeled two possibilities of hyperactive LLSR by either creating a tonic involuntary drive to cortex, or increasing the synaptic gain in cortical neurons. Both models are emulated using programmable very-large-scale-integrated-circuit hardware to test their sufficiency for producing dystonic symptoms. The emulation includes a joint with two Hill-type muscles, realistic muscle spindles, and 2,304 Izhikevich-type spiking neurons. The muscles are regulated by a monosynaptic spinal pathway with 32 ms delay and a long-latency pathway with 64 ms loop-delay representing transcortical/supra-spinal connections. Main results. When the limb is passively stretched, both models produce involuntary resistance with increased antagonist EMG responses similar to human data; also the muscle relaxation is delayed similar to human data. Both models predict reduced range of motion in voluntary movements. Significance. Although our model is a highly simplified and limited representation of reflex pathways, it shows that increased activity of the LLSR is by itself sufficient to cause many of the features of hypertonic dystonia.

A dual contribution to the involuntary semantic processing of unexpected spoken words.

PubMed

Parmentier, Fabrice B R; Turner, Jacqueline; Perez, Laura

2014-02-01

Sounds are a major cause of distraction. Unexpected to-be-ignored auditory stimuli presented in the context of an otherwise repetitive acoustic background ineluctably break through selective attention and distract people from an unrelated visual task (deviance distraction). This involuntary capture of attention by deviant sounds has been hypothesized to trigger their semantic appraisal and, in some circumstances, interfere with ongoing performance, but it remains unclear how such processing compares with the automatic processing of distractors in classic interference tasks (e.g., Stroop, flanker, Simon tasks). Using a cross-modal oddball task, we assessed the involuntary semantic processing of deviant sounds in the presence and absence of deviance distraction. The results revealed that some involuntary semantic analysis of spoken distractors occurs in the absence of deviance distraction but that this processing is significantly greater in its presence. We conclude that the automatic processing of spoken distractors reflects 2 contributions, one that is contingent upon deviance distraction and one that is independent from it.

Lifestyles and routine activities of South African teenagers at risk of being trafficked for involuntary prostitution.

PubMed

Lutya, Thozama Mandisa

2010-12-01

The United Nations estimates that 79% of teenage girls trafficked globally every year are forced into involuntary prostitution. About 247 000 South African children work in exploitative conditions; about 40 000 South African female teenagers work as prostitutes. This paper investigates lifestyles and routine activities of teenagers at risk of being trafficked for involuntary prostitution. The key concepts involuntary prostitution, intergenerational sex and exploitative conditions are defined in relation to the lifestyles and routine activities of South African female teenagers. Human trafficking for involuntary prostitution is described, based on a literature review. Lifestyle exposure and routine activities theories help to explain the potential victimisation of these teenagers in human trafficking for involuntary prostitution. Actual lifestyle and routine activities of South African teenagers and risky behaviours (substance abuse, intergenerational sex and child prostitution) are discussed as factors that make teens vulnerable to such trafficking. This paper recommends that human trafficking prevention efforts (awareness programmes and information campaigns) be directed at places frequented by human traffickers and teenagers in the absence of a capable guardian to reduce victimisation, as traffickers analyse the lifestyles and routine activities of their targets. South Africa should also interrogate entrenched practices such as intergenerational sex.

29 CFR 1625.9 - Prohibition of involuntary retirement.

Code of Federal Regulations, 2011 CFR

2011-07-01

....9 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION AGE DISCRIMINATION IN EMPLOYMENT ACT Interpretations § 1625.9 Prohibition of involuntary retirement. (a)(1) As...., the provision was not in the plan as the result of arbitrary discrimination on the basis of age. (2...

29 CFR 1625.9 - Prohibition of involuntary retirement.

Code of Federal Regulations, 2013 CFR

2013-07-01

....9 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION AGE DISCRIMINATION IN EMPLOYMENT ACT Interpretations § 1625.9 Prohibition of involuntary retirement. (a)(1) As...., the provision was not in the plan as the result of arbitrary discrimination on the basis of age. (2...

29 CFR 1625.9 - Prohibition of involuntary retirement.

Code of Federal Regulations, 2010 CFR

2010-07-01

....9 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION AGE DISCRIMINATION IN EMPLOYMENT ACT Interpretations § 1625.9 Prohibition of involuntary retirement. (a)(1) As...., the provision was not in the plan as the result of arbitrary discrimination on the basis of age. (2...

29 CFR 1625.9 - Prohibition of involuntary retirement.

Code of Federal Regulations, 2012 CFR

2012-07-01

....9 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION AGE DISCRIMINATION IN EMPLOYMENT ACT Interpretations § 1625.9 Prohibition of involuntary retirement. (a)(1) As...., the provision was not in the plan as the result of arbitrary discrimination on the basis of age. (2...

29 CFR 1625.9 - Prohibition of involuntary retirement.

Code of Federal Regulations, 2014 CFR

2014-07-01

....9 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION AGE DISCRIMINATION IN EMPLOYMENT ACT Interpretations § 1625.9 Prohibition of involuntary retirement. (a)(1) As...., the provision was not in the plan as the result of arbitrary discrimination on the basis of age. (2...

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).

Skeletal muscle mechanics: questions, problems and possible solutions.

PubMed

Herzog, Walter

2017-09-16

Skeletal muscle mechanics have been studied ever since people have shown an interest in human movement. However, our understanding of muscle contraction and muscle mechanical properties has changed fundamentally with the discovery of the sliding filament theory in 1954 and associated cross-bridge theory in 1957. Nevertheless, experimental evidence suggests that our knowledge of the mechanisms of contraction is far from complete, and muscle properties and muscle function in human movement remain largely unknown.In this manuscript, I am trying to identify some of the crucial challenges we are faced with in muscle mechanics, offer possible solutions to questions, and identify problems that might be worthwhile exploring in the future. Since it is impossible to tackle all (worthwhile) problems in a single manuscript, I identified three problems that are controversial, important, and close to my heart. They may be identified as follows: (i) mechanisms of muscle contraction, (ii) in vivo whole muscle mechanics and properties, and (iii) force-sharing among synergistic muscles. These topics are fundamental to our understanding of human movement and movement control, and they contain a series of unknowns and challenges to be explored in the future.It is my hope that this paper may serve as an inspiration for some, may challenge current beliefs in selected areas, tackle important problems in the area of muscle mechanics, physiology and movement control, and may guide and focus some of the thinking of future muscle mechanics research.

Activity patterns of the B31/B32 pattern initiators innervating the I2 muscle of the buccal mass during normal feeding movements in Aplysia californica.

PubMed

Hurwitz, I; Neustadter, D; Morton, D W; Chiel, H J; Susswein, A J

1996-04-01

1. B31 and B32 are pattern-initiator neurons in the buccal ganglia of Aplysia. Along with the B61/B62 neurons, B31/B32 are also motor neurons that innervate the 12 buccal muscle via the I2 nerve. This research was aimed at determining the physiological functions of the B31/B32 and B61/B62 neurons, and of the I2 muscle. 2. Stimulating the I2 muscle in the radula rest position produces radula protraction. In addition, in behaving animals lesioning either the muscle or the I2 nerve greatly reduces radula protraction. 3. During buccal motor programs in reduced preparations, B31/B32 and B61/62 fire preceding activity in neuron B4, whose firing indicates the onset of radula retraction. In addition, during both ingestion-like and rejection-like patterns the activity in the I2 nerve is correlated with protraction. 4. B31/B32 fire at frequencies of 15-25 Hz. Neither B31/B32 nor B61/B62 elicit facilitating end-junction potentials (EJPs) and electromyograms (EMGs) in the I2 muscle. EMGs from B31/B32 are smaller than those from B61/B62. B31/B32 and B61/B62 innervate all areas of the muscle approximately uniformly. 5. In behaving animals, EMGs consistent with B31/B32 activity are seen in the I2 muscle during the protraction phase of biting, swallowing, and rejection movements. In addition, the I2 muscle receives inputs that cannot be attributed to either the B31/B32 or B61/B62 neurons, either because the potentials are too large, firing frequencies are too low, or a prominent facilitation is seen. Such potentials are associated with lip movements, and also with radula retraction. 6. EMGs were recorded from the I2 muscle during feeding behavior after a lesion of the I2 nerve. Animals that had severe deficits in protraction showed no activity consistent with B31/B32 or B61/B62, but did show activity during retraction. 7. Our data indicate that the I2 muscle and the B31/B32 motor neurons are essential constituents contributing to protraction movements. Activity in these neurons is

Definition and classification of negative motor signs in childhood.

PubMed

Sanger, Terence D; Chen, Daofen; Delgado, Mauricio R; Gaebler-Spira, Deborah; Hallett, Mark; Mink, Jonathan W

2006-11-01

In this report we describe the outcome of a consensus meeting that occurred at the National Institutes of Health in Bethesda, Maryland, March 12 through 14, 2005. The meeting brought together 39 specialists from multiple clinical and research disciplines including developmental pediatrics, neurology, neurosurgery, orthopedic surgery, physical therapy, occupational therapy, physical medicine and rehabilitation, neurophysiology, muscle physiology, motor control, and biomechanics. The purpose of the meeting was to establish terminology and definitions for 4 aspects of motor disorders that occur in children: weakness, reduced selective motor control, ataxia, and deficits of praxis. The purpose of the definitions is to assist communication between clinicians, select homogeneous groups of children for clinical research trials, facilitate the development of rating scales to assess improvement or deterioration with time, and eventually to better match individual children with specific therapies. "Weakness" is defined as the inability to generate normal voluntary force in a muscle or normal voluntary torque about a joint. "Reduced selective motor control" is defined as the impaired ability to isolate the activation of muscles in a selected pattern in response to demands of a voluntary posture or movement. "Ataxia" is defined as an inability to generate a normal or expected voluntary movement trajectory that cannot be attributed to weakness or involuntary muscle activity about the affected joints. "Apraxia" is defined as an impairment in the ability to accomplish previously learned and performed complex motor actions that is not explained by ataxia, reduced selective motor control, weakness, or involuntary motor activity. "Developmental dyspraxia" is defined as a failure to have ever acquired the ability to perform age-appropriate complex motor actions that is not explained by the presence of inadequate demonstration or practice, ataxia, reduced selective motor control

Bio-inspired Hybrid Carbon Nanotube Muscles

NASA Astrophysics Data System (ADS)

Kim, Tae Hyeob; Kwon, Cheong Hoon; Lee, Changsun; An, Jieun; Phuong, Tam Thi Thanh; Park, Sun Hwa; Lima, Márcio D.; Baughman, Ray H.; Kang, Tong Mook; Kim, Seon Jeong

2016-05-01

There has been continuous progress in the development for biomedical engineering systems of hybrid muscle generated by combining skeletal muscle and artificial structure. The main factor affecting the actuation performance of hybrid muscle relies on the compatibility between living cells and their muscle scaffolds during cell culture. Here, we developed a hybrid muscle powered by C2C12 skeletal muscle cells based on the functionalized multi-walled carbon nanotubes (MWCNT) sheets coated with poly(3,4-ethylenedioxythiophene) (PEDOT) to achieve biomimetic actuation. This hydrophilic hybrid muscle is physically durable in solution and responds to electric field stimulation with flexible movement. Furthermore, the biomimetic actuation when controlled by electric field stimulation results in movement similar to that of the hornworm by patterned cell culture method. The contraction and relaxation behavior of the PEDOT/MWCNT-based hybrid muscle is similar to that of the single myotube movement, but has faster relaxation kinetics because of the shape-maintenance properties of the freestanding PEDOT/MWCNT sheets in solution. Our development provides the potential possibility for substantial innovation in the next generation of cell-based biohybrid microsystems.

The Relationship Between Postural and Movement Stability.

PubMed

Feldman, Anatol G

2016-01-01

Postural stabilization is provided by stretch reflexes, intermuscular reflexes, and intrinsic muscle properties. Taken together, these posture-stabilizing mechanisms resist deflections from the posture at which balance of muscle and external forces is maintained. Empirical findings suggest that for each muscle, these mechanisms become functional at a specific, spatial threshold-the muscle length or respective joint angle at which motor units begin to be recruited. Empirical data suggest that spinal and supraspinal centers can shift the spatial thresholds for a group of muscles that stabilized the initial posture. As a consequence, the same stabilizing mechanisms, instead of resisting motion from the initial posture, drive the body to another stable posture. In other words by shifting spatial thresholds, the nervous system converts movement resisting to movement-producing mechanisms. It is illustrated that, contrary to conventional view, this control strategy allows the system to transfer body balance to produce locomotion and other actions without loosing stability at any point of them. It also helps orient posture and movement with the direction of gravity. It is concluded that postural and movement stability is provided by a common mechanism.

Rat Whisker Movement after Facial Nerve Lesion: Evidence for Autonomic Contraction of Skeletal Muscle

PubMed Central

Heaton, James T.; Sheu, Shu-Hsien; Hohman, Marc H.; Knox, Christopher J.; Weinberg, Julie S.; Kleiss, Ingrid J.; Hadlock, Tessa A.

2014-01-01

Vibrissal whisking is often employed to track facial nerve regeneration in rats; however, we have observed similar degrees of whisking recovery after facial nerve transection with or without repair. We hypothesized that the source of non-facial nerve-mediated whisker movement after chronic denervation was from autonomic, cholinergic axons traveling within the infraorbital branch of the trigeminal nerve (ION). Rats underwent unilateral facial nerve transection with repair (N=7) or resection without repair (N=11). Post-operative whisking amplitude was measured weekly across 10 weeks, and during intraoperative stimulation of the ION and facial nerves at ≥18 weeks. Whisking was also measured after subsequent ION transection (N=6) or pharmacologic blocking of the autonomic ganglia using hexamethonium (N=3), and after snout cooling intended to elicit a vasodilation reflex (N=3). Whisking recovered more quickly and with greater amplitude in rats that underwent facial nerve repair compared to resection (P<0.05), but individual rats overlapped in whisking amplitude across both groups. In the resected rats, non-facial-nerve mediated whisking was elicited by electrical stimulation of the ION, temporarily diminished following hexamethonium injection, abolished by transection of the ION, and rapidly and significantly (P<0.05) increased by snout cooling. Moreover, fibrillation-related whisker movements decreased in all rats during the initial recovery period (indicative of reinnervation), but re-appeared in the resected rats after undergoing ION transection (indicative of motor denervation). Cholinergic, parasympathetic axons traveling within the ION innervate whisker pad vasculature, and immunohistochemistry for vasoactive intestinal peptide revealed these axons branching extensively over whisker pad muscles and contacting neuromuscular junctions after facial nerve resection. This study provides the first behavioral and anatomical evidence of spontaneous autonomic innervation

Rat whisker movement after facial nerve lesion: evidence for autonomic contraction of skeletal muscle.

PubMed

Heaton, James T; Sheu, Shu Hsien; Hohman, Marc H; Knox, Christopher J; Weinberg, Julie S; Kleiss, Ingrid J; Hadlock, Tessa A

2014-04-18

Vibrissal whisking is often employed to track facial nerve regeneration in rats; however, we have observed similar degrees of whisking recovery after facial nerve transection with or without repair. We hypothesized that the source of non-facial nerve-mediated whisker movement after chronic denervation was from autonomic, cholinergic axons traveling within the infraorbital branch of the trigeminal nerve (ION). Rats underwent unilateral facial nerve transection with repair (N=7) or resection without repair (N=11). Post-operative whisking amplitude was measured weekly across 10weeks, and during intraoperative stimulation of the ION and facial nerves at ⩾18weeks. Whisking was also measured after subsequent ION transection (N=6) or pharmacologic blocking of the autonomic ganglia using hexamethonium (N=3), and after snout cooling intended to elicit a vasodilation reflex (N=3). Whisking recovered more quickly and with greater amplitude in rats that underwent facial nerve repair compared to resection (P<0.05), but individual rats overlapped in whisking amplitude across both groups. In the resected rats, non-facial-nerve-mediated whisking was elicited by electrical stimulation of the ION, temporarily diminished following hexamethonium injection, abolished by transection of the ION, and rapidly and significantly (P<0.05) increased by snout cooling. Moreover, fibrillation-related whisker movements decreased in all rats during the initial recovery period (indicative of reinnervation), but re-appeared in the resected rats after undergoing ION transection (indicative of motor denervation). Cholinergic, parasympathetic axons traveling within the ION innervate whisker pad vasculature, and immunohistochemistry for vasoactive intestinal peptide revealed these axons branching extensively over whisker pad muscles and contacting neuromuscular junctions after facial nerve resection. This study provides the first behavioral and anatomical evidence of spontaneous autonomic innervation

Renal vascular responses to static handgrip: role of muscle mechanoreflex

NASA Technical Reports Server (NTRS)

Momen, Afsana; Leuenberger, Urs A.; Ray, Chester A.; Cha, Susan; Handly, Brian; Sinoway, Lawrence I.

2003-01-01

During exercise, the sympathetic nervous system is activated, which causes vasoconstriction. The autonomic mechanisms responsible for this vasoconstriction vary based on the particular tissue being studied. Attempts to examine reflex control of the human renal circulation have been difficult because of technical limitations. In this report, the Doppler technique was used to examine renal flow velocity during four muscle contraction paradigms in conscious humans. Flow velocity was divided by mean arterial blood pressure to yield an index of renal vascular resistance (RVR). Fatiguing static handgrip (40% of maximal voluntary contraction) increased RVR by 76%. During posthandgrip circulatory arrest, RVR remained above baseline (2.1 +/- 0.2 vs. 2.8 +/- 0.2 arbitrary units; P < 0.017) but was only 40% of the end-grip RVR value. Voluntary biceps contraction increased RVR within 10 s of initiation of contraction. This effect was not associated with an increase in blood pressure. Finally, involuntary biceps contraction also raised RVR. We conclude that muscle contraction evokes renal vasoconstriction in conscious humans. The characteristic of this response is consistent with a primary role for mechanically sensitive afferents. This statement is based on the small posthandgrip circulatory arrest response and the vasoconstriction that was observed with involuntary biceps contraction.

5 CFR 890.1112 - Denial of continuation of coverage due to involuntary separation for gross misconduct.

Code of Federal Regulations, 2010 CFR

2010-01-01

... involuntary separation for gross misconduct. 890.1112 Section 890.1112 Administrative Personnel OFFICE OF... involuntary separation for gross misconduct. (a) Notice of denial. (1) When an employing office determines that the offense for which an employee is being removed constitutes gross misconduct for the purpose of...

5 CFR 890.1112 - Denial of continuation of coverage due to involuntary separation for gross misconduct.

Code of Federal Regulations, 2011 CFR

2011-01-01

... involuntary separation for gross misconduct. 890.1112 Section 890.1112 Administrative Personnel OFFICE OF... involuntary separation for gross misconduct. (a) Notice of denial. (1) When an employing office determines that the offense for which an employee is being removed constitutes gross misconduct for the purpose of...

5 CFR 890.1112 - Denial of continuation of coverage due to involuntary separation for gross misconduct.

Code of Federal Regulations, 2014 CFR

2014-01-01

... involuntary separation for gross misconduct. 890.1112 Section 890.1112 Administrative Personnel OFFICE OF... involuntary separation for gross misconduct. (a) Notice of denial. (1) When an employing office determines that the offense for which an employee is being removed constitutes gross misconduct for the purpose of...

5 CFR 890.1112 - Denial of continuation of coverage due to involuntary separation for gross misconduct.

Code of Federal Regulations, 2013 CFR

2013-01-01

... involuntary separation for gross misconduct. 890.1112 Section 890.1112 Administrative Personnel OFFICE OF... involuntary separation for gross misconduct. (a) Notice of denial. (1) When an employing office determines that the offense for which an employee is being removed constitutes gross misconduct for the purpose of...

5 CFR 890.1112 - Denial of continuation of coverage due to involuntary separation for gross misconduct.

Code of Federal Regulations, 2012 CFR

2012-01-01

... involuntary separation for gross misconduct. 890.1112 Section 890.1112 Administrative Personnel OFFICE OF... involuntary separation for gross misconduct. (a) Notice of denial. (1) When an employing office determines that the offense for which an employee is being removed constitutes gross misconduct for the purpose of...

Fiducial marker-based correction for involuntary motion in weight-bearing C-arm CT scanning of knees. Part I. Numerical model-based optimization.

PubMed

Choi, Jang-Hwan; Fahrig, Rebecca; Keil, Andreas; Besier, Thor F; Pal, Saikat; McWalter, Emily J; Beaupré, Gary S; Maier, Andreas

2013-09-01

Human subjects in standing positions are apt to show much more involuntary motion than in supine positions. The authors aimed to simulate a complicated realistic lower body movement using the four-dimensional (4D) digital extended cardiac-torso (XCAT) phantom. The authors also investigated fiducial marker-based motion compensation methods in two-dimensional (2D) and three-dimensional (3D) space. The level of involuntary movement-induced artifacts and image quality improvement were investigated after applying each method. An optical tracking system with eight cameras and seven retroreflective markers enabled us to track involuntary motion of the lower body of nine healthy subjects holding a squat position at 60° of flexion. The XCAT-based knee model was developed using the 4D XCAT phantom and the optical tracking data acquired at 120 Hz. The authors divided the lower body in the XCAT into six parts and applied unique affine transforms to each so that the motion (6 degrees of freedom) could be synchronized with the optical markers' location at each time frame. The control points of the XCAT were tessellated into triangles and 248 projection images were created based on intersections of each ray and monochromatic absorption. The tracking data sets with the largest motion (Subject 2) and the smallest motion (Subject 5) among the nine data sets were used to animate the XCAT knee model. The authors defined eight skin control points well distributed around the knees as pseudo-fiducial markers which functioned as a reference in motion correction. Motion compensation was done in the following ways: (1) simple projection shifting in 2D, (2) deformable projection warping in 2D, and (3) rigid body warping in 3D. Graphics hardware accelerated filtered backprojection was implemented and combined with the three correction methods in order to speed up the simulation process. Correction fidelity was evaluated as a function of number of markers used (4-12) and marker distribution

32 CFR Appendix C to Part 113 - Sample DD Form 2653, “Involuntary Allotment Application”

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 1 2010-07-01 2010-07-01 false Sample DD Form 2653, âInvoluntary Allotment Applicationâ C Appendix C to Part 113 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE... Part 113—Sample DD Form 2653, “Involuntary Allotment Application” ER05JA95.002 ER05JA95.003 ...

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…

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…

Insulin-like growth factor-1 enhances rat skeletal muscle charge movement and L-type Ca2+ channel gene expression

PubMed Central

Wang, Zhong-Min; Laura Messi, María; Renganathan, Muthukrishnan; Delbono, Osvaldo

1999-01-01

We investigated whether insulin-like growth factor-1 (IGF-1), an endogenous potent activator of skeletal muscle proliferation and differentiation, enhances L-type Ca2+ channel gene expression resulting in increased functional voltage sensors in single skeletal muscle cells. Charge movement and inward Ca2+ current were recorded in primary cultured rat myoballs using the whole-cell configuration of the patch-clamp technique. Ca2+ current and maximum charge movement (Qmax) were potentiated in cells treated with IGF-1 without significant changes in their voltage dependence. Peak Ca2+ current in control and IGF-1-treated cells was -7·8 ± 0·44 and -10·5 ± 0·37 pA pF−1, respectively (P < 0·01), whilst Qmax was 12·9 ± 0·4 and 22·0 ± 0·3 nC μF−1, respectively (P < 0·01). The number of L-type Ca2+ channels was found to increase in the same preparation. The maximum binding capacity (Bmax) of the high-affinity radioligand [3H]PN200-110 in control and IGF-1-treated cells was 1·21 ± 0·25 and 3·15 ± 0·5 pmol (mg protein)−1, respectively (P < 0·01). No significant change in the dissociation constant for [3H]PN200-110 was found. Antisense RNA amplification showed a significant increase in the level of mRNA encoding the L-type Ca2+ channel α1-subunit in IGF-1-treated cells. This study demonstrates that IGF-1 regulates charge movement and the level of L-type Ca2+ channel α1-subunits through activation of gene expression in skeletal muscle cells. PMID:10087334

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.

Speech motor development: Integrating muscles, movements, and linguistic units.

PubMed

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 language production models. A review of the literature on adult speakers suggests that they engage complex, parallel processes involving many units, including sentence, phrase, syllable, and phoneme levels. Infants must develop multilayered interactions among language and motor systems. This discussion describes recent studies of speech motor performance relative to varying linguistic goals during the childhood, teenage, and young adult years. Studies of the developing interactions between speech motor and language systems reveal both qualitative and quantitative differences between the developing and the mature systems. These studies provide an experimental basis for a more comprehensive theoretical account of how mappings between units of language and units of action are formed and how they function. Readers will be able to: (1) understand the theoretical differences between models of speech motor control and models of language processing, as well as the nature of the concepts used in the two different kinds of models, (2) explain the concept of coarticulation and state why this phenomenon has confounded attempts to determine the role of linguistic units, such as syllables and phonemes, in speech production, (3) describe the development of speech motor performance skills and specify quantitative and qualitative differences between speech motor performance in children and adults, and (4) describe experimental methods that allow scientists to study speech and limb motor control, as well as compare units of action used to study non-speech and speech movements.

Involuntary vs. voluntary hospital admission. A systematic literature review on outcome diversity.

PubMed

Kallert, Thomas W; Glöckner, Matthias; Schützwohl, Matthias

2008-06-01

This article systematically reviews the literature on the outcome of acute hospitalization for adult general psychiatric patients admitted involuntarily as compared to patients admitted voluntarily. Inclusion and exclusion criteria qualified 41 out of 3,227 references found in Medline and PSYNDEXplus literature searches for this review. The authors independently rated these articles on six pre-defined indicators of research quality, carried out statistical comparisons ex-post facto where not reported, and computed for each adequate result the effect size index d for the comparison of means, and the Phi- or contingency coefficient for cross-tabulated data. Methodological quality of the studies, coming mostly from North American and European countries, showed significant variation and was higher concerning service-related than clinical or subjective outcomes. Main deficits appeared in sample size estimation, lack of clear follow-up time-points, and the absence of standardized instruments used to assess clinical outcomes. Length of stay, readmission risk, and risk of involuntary readmission were at least equal or greater for involuntary patients. Involuntary patients showed no increased mortality, but did have higher suicide rates than voluntary patients. Further, involuntary patients demonstrated lower levels of social functioning, and equal levels of general psychopathology and treatment compliance; they were more dissatisfied with treatment and more frequently felt that hospitalization was not justified. Future methodologically-sound studies exploring this topic should focus on patient populations not represented here. Further research should also clarify if the legal admission status is sufficiently valid for differentiating the outcome of acute hospitalization.

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.

Different corticospinal control between discrete and rhythmic movement of the ankle.

PubMed

Goto, Yumeno; Jono, Yasutomo; Hatanaka, Ryota; Nomura, Yoshifumi; Tani, Keisuke; Chujo, Yuta; Hiraoka, Koichi

2014-01-01

We investigated differences in corticospinal and spinal control between discrete and rhythmic ankle movements. Motor evoked potentials (MEPs) in the tibialis anterior and soleus muscles and soleus H-reflex were elicited in the middle of the plantar flexion phase during discrete ankle movement or in the initial or later cycles of rhythmic ankle movement. The H-reflex was evoked at an intensity eliciting a small M-wave and MEPs were elicited at an intensity of 1.2 times the motor threshold of the soleus MEPs. Only trials in which background EMG level, ankle angle, and ankle velocity were similar among the movement conditions were included for data analysis. In addition, only trials with a similar M-wave were included for data analysis in the experiment evoking H-reflexes. Results showed that H reflex and MEP amplitudes in the soleus muscle during discrete movement were not significantly different from those during rhythmic movement. MEP amplitude in the tibialis anterior muscle during the later cycles of rhythmic movement was significantly larger than that during the initial cycle of the rhythmic movement or during discrete movement. Higher corticospinal excitability in the tibialis anterior muscle during the later cycles of rhythmic movement may reflect changes in corticospinal control from the initial cycle to the later cycles of rhythmic movement.

GRIN1 mutations cause encephalopathy with infantile-onset epilepsy, and hyperkinetic and stereotyped movement disorders.

PubMed

Ohba, Chihiro; Shiina, Masaaki; Tohyama, Jun; Haginoya, Kazuhiro; Lerman-Sagie, Tally; Okamoto, Nobuhiko; Blumkin, Lubov; Lev, Dorit; Mukaida, Souichi; Nozaki, Fumihito; Uematsu, Mitsugu; Onuma, Akira; Kodera, Hirofumi; Nakashima, Mitsuko; Tsurusaki, Yoshinori; Miyake, Noriko; Tanaka, Fumiaki; Kato, Mitsuhiro; Ogata, Kazuhiro; Saitsu, Hirotomo; Matsumoto, Naomichi

2015-06-01

Recently, de novo mutations in GRIN1 have been identified in patients with nonsyndromic intellectual disability and epileptic encephalopathy. Whole exome sequencing (WES) analysis of patients with genetically unsolved epileptic encephalopathies identified four patients with GRIN1 mutations, allowing us to investigate the phenotypic spectrum of GRIN1 mutations. Eighty-eight patients with unclassified early onset epileptic encephalopathies (EOEEs) with an age of onset <1 year were analyzed by WES. The effect of mutations on N-methyl-D-aspartate (NMDA) receptors was examined by mapping altered amino acids onto three-dimensional models. We identified four de novo missense GRIN1 mutations in 4 of 88 patients with unclassified EOEEs. In these four patients, initial symptoms appeared within 3 months of birth, including hyperkinetic movements in two patients (2/4, 50%), and seizures in two patients (2/4, 50%). Involuntary movements, severe developmental delay, and intellectual disability were recognized in all four patients. In addition, abnormal eye movements resembling oculogyric crises and stereotypic hand movements were observed in two and three patients, respectively. All the four patients exhibited only nonspecific focal and diffuse epileptiform abnormality, and never showed suppression-burst or hypsarrhythmia during infancy. A de novo mosaic mutation (c.1923G>A) with a mutant allele frequency of 16% (in DNA of blood leukocytes) was detected in one patient. Three mutations were located in the transmembrane domain (3/4, 75%), and one in the extracellular loop near transmembrane helix 1. All the mutations were predicted to impair the function of the NMDA receptor. Clinical features of de novo GRIN1 mutations include infantile involuntary movements, seizures, and hand stereotypies, suggesting that GRIN1 mutations cause encephalopathy resulting in seizures and movement disorders. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

I want to move, but cannot: characteristics of involuntary stayers and associations with health among Canadian seniors.

PubMed

Strohschein, Lisa

2012-08-01

The purpose of this study was to investigate characteristics of seniors in the Canadian population who are involuntary stayers and to assess associations with health. Data come from the 1994 Canadian National Population Health Survey, with the sample restricted to those 65 and older (N = 2,551). Nearly 1 in 10 seniors identified as an involuntary stayer. Seniors with few socioeconomic resources, poor health, greater need for assistance, and low social involvement were more likely to identify as an involuntary stayer. Furthermore, seniors who were involuntary stayers report significantly more distress and greater odds of low self-rated health than other seniors. This study brings into visibility an understudied segment of the elderly population: seniors who are unable to move from their present location despite their desire to do so. Further research and policy responses assisting seniors to age in a setting of their own choosing are needed.

Coactivation of the elbow antagonist muscles is not affected by the speed of movement in isokinetic exercise.

PubMed

Bazzucchi, Ilenia; Sbriccoli, Paola; Marzattinocci, Giulia; Felici, Francesco

2006-02-01

Since muscle coactivation increases the stiffness and stability of a joint, greater coactivation is likely during faster than slower movements. Very few studies, though, have been conducted to verify this hypothesis. Moreover, a large number of studies have examined coactivation of muscles surrounding the knee joint whereas there are few reports on the elbow joint. The aim of this study was therefore to compare the antagonist activation of the elbow flexors and extensors during isokinetic concentric exercises and to investigate the influence of angular velocity on their activation. Twelve men participated in the study. The surface electromyographic signals (sEMG) were recorded from the biceps brachii (BB) and triceps brachii (TB) muscles during three maximal voluntary isometric contractions (MVC) of elbow flexors and extensors and a set of three maximal elbow flexions and extensions each at 15 degrees, 30 degrees , 60 degrees, 120 degrees, 180 degrees, and 240 degrees.s(-1). Normalized root mean square (RMS) of sEMG was calculated during the isokinetic phase of movement as an index of sEMG amplitude. During elbow flexion, the antagonist activation of BB averaged 16.2% lower than TB, and this difference was statistically significant at all angular velocities. The normalized RMS values ranged from 26.0% +/- 19.0 at MVC to 37.8% +/- 13.9 at 240 degrees.s(-1) for antagonist TB activation, and from 5.7% +/- 5.2 at MVC to 18.9% +/- 8.6 at 240 degrees.s(-1) for antagonist BB activation. No influence of angular velocity on agonist and antagonist activity was found. Moreover, flexion and extension torques were both strongly affected by the amount of antagonist activation. The functional specialization of the two muscle groups could be responsible for the different levels of antagonist activation. The frequent use of BB, which is not assisted by gravity during daily activities, could lead to reduced coactivation due to a better functioning of the control system based upon

Who cares for involuntary clients?

PubMed

Soliman, Soheil; Pollack, Harold A; Alexander, Jeffrey A

2009-01-01

The objectives of this study were to compare characteristics of outpatient substance abuse treatment (OSAT) units that serve high proportions of involuntary clients (ICs) with those that serve a low percentage of such clients. The authors analyze unit-level 1995-2005 data from the National Drug Abuse Treatment System Survey (NDATSS). Approximately 1/6 of OSAT units draw the dominant majority of their clients from involuntary referrals. OSAT units that treat a high proportion of ICs are less likely to be accredited by professional organizations, have fewer treatment staff with advanced degrees, and have shorter average treatment duration than do OSAT units that serve few ICs. OSAT units that serve ICs are more likely to offer legal and domestic violence services but are less likely to offer mental health services or aftercare. OSAT units that serve ICs are less likely to be hospital-affiliated than are other units. Clients at such facilities are more likely to be convicted of driving while intoxicated (DWI), are younger, are less likely to have received prior treatment, are more likely to remain abstinent after treatment, but are more likely to be remanded back to courts. The authors conclude that ICs are an important market niche in OSAT care. DWI is by far the most common offense reported in units that specialize in ICs. Aside from legal and domestic violence services, units with a high proportion of ICs appear to offer somewhat less intensive and professionalized services than do other facilities; however, clients at these units are more likely to be abstinent at the end of treatment and but more likely to be remanded back to the courts.

Individual muscle control using an exoskeleton robot for muscle function testing.

PubMed

Ueda, Jun; Ming, Ding; Krishnamoorthy, Vijaya; Shinohara, Minoru; Ogasawara, Tsukasa

2010-08-01

Healthy individuals modulate muscle activation patterns according to their intended movement and external environment. Persons with neurological disorders (e.g., stroke and spinal cord injury), however, have problems in movement control due primarily to their inability to modulate their muscle activation pattern in an appropriate manner. A functionality test at the level of individual muscles that investigates the activity of a muscle of interest on various motor tasks may enable muscle-level force grading. To date there is no extant work that focuses on the application of exoskeleton robots to induce specific muscle activation in a systematic manner. This paper proposes a new method, named "individual muscle-force control" using a wearable robot (an exoskeleton robot, or a power-assisting device) to obtain a wider variety of muscle activity data than standard motor tasks, e.g., pushing a handle by hand. A computational algorithm systematically computes control commands to a wearable robot so that a desired muscle activation pattern for target muscle forces is induced. It also computes an adequate amount and direction of a force that a subject needs to exert against a handle by his/her hand. This individual muscle control method enables users (e.g., therapists) to efficiently conduct neuromuscular function tests on target muscles by arbitrarily inducing muscle activation patterns. This paper presents a basic concept, mathematical formulation, and solution of the individual muscle-force control and its implementation to a muscle control system with an exoskeleton-type robot for upper extremity. Simulation and experimental results in healthy individuals justify the use of an exoskeleton robot for future muscle function testing in terms of the variety of muscle activity data.

Emotional reactions to involuntary psychiatric hospitalization and stigma-related stress among people with mental illness.

PubMed

Rüsch, Nicolas; Müller, Mario; Lay, Barbara; Corrigan, Patrick W; Zahn, Roland; Schönenberger, Thekla; Bleiker, Marco; Lengler, Silke; Blank, Christina; Rössler, Wulf

2014-02-01

Compulsory admission to psychiatric inpatient treatment can be experienced as disempowering and stigmatizing by people with serious mental illness. However, quantitative studies of stigma-related emotional and cognitive reactions to involuntary hospitalization and their impact on people with mental illness are scarce. Among 186 individuals with serious mental illness and a history of recent involuntary hospitalization, shame and self-contempt as emotional reactions to involuntary hospitalization, the cognitive appraisal of stigma as a stressor, self-stigma, empowerment as well as quality of life and self-esteem were assessed by self-report. Psychiatric symptoms were rated by the Brief Psychiatric Rating Scale. In multiple linear regressions, more self-stigma was predicted independently by higher levels of shame, self-contempt and stigma stress. A greater sense of empowerment was related to lower levels of stigma stress and self-contempt. These findings remained significant after controlling for psychiatric symptoms, diagnosis, age, gender and the number of lifetime involuntary hospitalizations. Increased self-stigma and reduced empowerment in turn predicted poorer quality of life and reduced self-esteem. The negative effect of emotional reactions and stigma stress on quality of life and self-esteem was largely mediated by increased self-stigma and reduced empowerment. Shame and self-contempt as reactions to involuntary hospitalization as well as stigma stress may lead to self-stigma, reduced empowerment and poor quality of life. Emotional and cognitive reactions to coercion may determine its impact more than the quantity of coercive experiences. Interventions to reduce the negative effects of compulsory admissions should address emotional reactions and stigma as a stressor.

Sarcopenia, cachexia, and muscle performance in heart failure: Review update 2016.

PubMed

Saitoh, Masakazu; Ishida, Junichi; Doehner, Wolfram; von Haehling, Stephan; Anker, Markus S; Coats, Andrew J S; Anker, Stefan D; Springer, Jochen

2017-07-01

Cachexia in the context of heart failure (HF) has been termed cardiac cachexia, and represents a progressive involuntary weight loss. Cachexia is mainly the result of an imbalance in the homeostasis of muscle protein synthesis and degradation due to a lower activity of protein synthesis pathways and an over-activation of protein degradation. In addition, muscle wasting leads to of impaired functional capacity, even after adjusting for clinical relevant variables in patients with HF. However, there is no sufficient therapeutic strategy in muscle wasting in HF patients and very few studies in animal models. Exercise training represents a promising intervention that can prevent or even reverse the process of muscle wasting, and worsening the muscle function and performance in HF with muscle wasting and cachexia. The pathological mechanisms and effective therapeutic approach of cardiac cachexia remain uncertain, because of the difficulty to establish animal cardiac cachexia models, thus novel animal models are warranted. Furthermore, the use of improved animal models will lead to a better understanding of the pathways that modulate muscle wasting and therapeutics of muscle wasting of cardiac cachexia. Copyright © 2017 Elsevier B.V. All rights reserved.

Motor plan differs for young and older adults during similar movements.

PubMed

Casamento-Moran, Agostina; Chen, Yen-Ting; Lodha, Neha; Yacoubi, Basma; Christou, Evangelos A

2017-04-01

Older adults exhibit altered activation of the agonist and antagonist muscles during goal-directed movements compared with young adults. However, it remains unclear whether the differential activation of the antagonistic muscles in older adults results from an impaired motor plan or an altered ability of the muscle to contract. The purpose of this study, therefore, was to determine whether the motor plan differs for young and older adults. Ten young (26.1 ± 4.3 yr, 4 women) and 16 older adults (71.9 ± 6.9 yr, 9 women) participated in the study. Participants performed 100 trials of fast goal directed movements with ankle dorsiflexion while we recorded the electromyographic activity of the primary agonist (tibialis anterior; TA) and antagonist (soleus; SOL) muscles. From those 100 trials we selected 5 trials in each of 3 movement end-point categories (fast, accurate, and slow). We investigated age-associated differences in the motor plan by quantifying the individual activity and coordination of the agonist and antagonist muscles. During similar movement end points, older adults exhibited similar activation of the agonist (TA) and antagonist (SOL) muscles compared with young adults. In addition, the coordination of the agonist and antagonist muscles (TA and SOL) was different between the two age groups. Specifically, older adults exhibited lower TA-SOL overlap ( F 1,23 = 41.2, P < 0.001) and greater TA-SOL peak EMG delay ( F 1,25 = 35.5, P < 0.001). This finding suggests that although subjects in both age groups displayed similar movement end points, they exhibited a different motor plan, as demonstrated by altered coordination between the agonist and antagonist muscles. NEW & NOTEWORTHY We aimed to determine whether the altered activation of muscles in older adults compared with young adults during fast goal-directed movements is related to an altered motor plan. For matched movements, there were differences in the coordination of antagonistic muscles but no

Locomotor-Like Leg Movements Evoked by Rhythmic Arm Movements in Humans

PubMed Central

Sylos-Labini, Francesca; Ivanenko, Yuri P.; MacLellan, Michael J.; Cappellini, Germana; Poppele, Richard E.; Lacquaniti, Francesco

2014-01-01

Motion of the upper limbs is often coupled to that of the lower limbs in human bipedal locomotion. It is unclear, however, whether the functional coupling between upper and lower limbs is bi-directional, i.e. whether arm movements can affect the lumbosacral locomotor circuitry. Here we tested the effects of voluntary rhythmic arm movements on the lower limbs. Participants lay horizontally on their side with each leg suspended in an unloading exoskeleton. They moved their arms on an overhead treadmill as if they walked on their hands. Hand-walking in the antero-posterior direction resulted in significant locomotor-like movements of the legs in 58% of the participants. We further investigated quantitatively the responses in a subset of the responsive subjects. We found that the electromyographic (EMG) activity of proximal leg muscles was modulated over each cycle with a timing similar to that of normal locomotion. The frequency of kinematic and EMG oscillations in the legs typically differed from that of arm oscillations. The effect of hand-walking was direction specific since medio-lateral arm movements did not evoke appreciably leg air-stepping. Using externally imposed trunk movements and biomechanical modelling, we ruled out that the leg movements associated with hand-walking were mainly due to the mechanical transmission of trunk oscillations. EMG activity in hamstring muscles associated with hand-walking often continued when the leg movements were transiently blocked by the experimenter or following the termination of arm movements. The present results reinforce the idea that there exists a functional neural coupling between arm and legs. PMID:24608249

Different corticospinal control between discrete and rhythmic movement of the ankle

PubMed Central

Goto, Yumeno; Jono, Yasutomo; Hatanaka, Ryota; Nomura, Yoshifumi; Tani, Keisuke; Chujo, Yuta; Hiraoka, Koichi

2014-01-01

We investigated differences in corticospinal and spinal control between discrete and rhythmic ankle movements. Motor evoked potentials (MEPs) in the tibialis anterior and soleus muscles and soleus H-reflex were elicited in the middle of the plantar flexion phase during discrete ankle movement or in the initial or later cycles of rhythmic ankle movement. The H-reflex was evoked at an intensity eliciting a small M-wave and MEPs were elicited at an intensity of 1.2 times the motor threshold of the soleus MEPs. Only trials in which background EMG level, ankle angle, and ankle velocity were similar among the movement conditions were included for data analysis. In addition, only trials with a similar M-wave were included for data analysis in the experiment evoking H-reflexes. Results showed that H reflex and MEP amplitudes in the soleus muscle during discrete movement were not significantly different from those during rhythmic movement. MEP amplitude in the tibialis anterior muscle during the later cycles of rhythmic movement was significantly larger than that during the initial cycle of the rhythmic movement or during discrete movement. Higher corticospinal excitability in the tibialis anterior muscle during the later cycles of rhythmic movement may reflect changes in corticospinal control from the initial cycle to the later cycles of rhythmic movement. PMID:25126066

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.

Effects of experimental muscle pain on muscle activity and co-ordination during static and dynamic motor function.

PubMed

Graven-Nielsen, T; Svensson, P; Arendt-Nielsen, L

1997-04-01

The relation between muscle pain, muscle activity, and muscle co-ordination is still controversial. The present human study investigates the influence of experimental muscle pain on resting, static, and dynamic muscle activity. In the resting and static experiments, the electromyography (EMG) activity and the contraction force of m. tibialis anterior were assessed before and after injection of 0.5 ml hypertonic saline (5%) into the same muscle. In the dynamic experiment, injections of 0.5 ml hypertonic saline (5%) were performed into either m. tibialis anterior (TA) or m. gastrocnemius (GA) and the muscle activity and co-ordination were investigated during gait on a treadmill by EMG recordings from m. TA and m. GA. At rest no evidence of EMG hyperactivity was found during muscle pain. The maximal voluntary contraction (MVC) during muscle pain was significantly lower than the control condition (P < 0.05). During a static contraction at 80% of the pre-pain MVC muscle pain caused a significant reduction in endurance time (P < 0.043). During dynamic contractions, muscle pain resulted in a significant decrease of the EMG activity in the muscle, agonistic to the painful muscle (P < 0.05), and a significant increase of the EMG activity of the muscle, antagonistic to the painful muscle (P < 0.05). Muscle pain seems to cause a general protection of painful muscles during both static and dynamic contractions. The increased EMG activity of the muscle antagonistic to the painful muscle is probably a functional adaptation of muscle co-ordination in order to limit movements. Modulation of muscle activity by muscle pain could be controlled via inhibition of muscles agonistic to the movement and/or excitation of muscles antagonistic to the movement. The present results are in accordance with the pain-adaptation model (Lund, J.P., Stohler, C.S. and Widmer, C.G. In: H. Vaerøy and H. Merskey (Eds.), Progress in Fibromyalgia and Myofascial Pain. Elsevier, Amsterdam, 1993, pp. 311

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.

Human-Computer Interface Controlled by Horizontal Directional Eye Movements and Voluntary Blinks Using AC EOG Signals

NASA Astrophysics Data System (ADS)

Kajiwara, Yusuke; Murata, Hiroaki; Kimura, Haruhiko; Abe, Koji

As a communication support tool for cases of amyotrophic lateral sclerosis (ALS), researches on eye gaze human-computer interfaces have been active. However, since voluntary and involuntary eye movements cannot be distinguished in the interfaces, their performance is still not sufficient for practical use. This paper presents a high performance human-computer interface system which unites high quality recognitions of horizontal directional eye movements and voluntary blinks. The experimental results have shown that the number of incorrect inputs is decreased by 35.1% in an existing system which equips recognitions of horizontal and vertical directional eye movements in addition to voluntary blinks and character inputs are speeded up by 17.4% from the existing system.

[German practice of involuntary commitment at both federal and state level after introduction of the Guardianship law (1992-2009)].

PubMed

Valdes-Stauber, J; Deinert, H; Kilian, R

2012-05-01

Given the steady rise of psychiatric coercive measures in Germany, the question arises whether this development is significantly influenced by the corresponding legal basis or through epidemiological, socio-economic or socio-structural factors. Based on full surveys of the Federal Ministry of Justice we examined the development and associations of 10 indicators of coercive psychiatric measures over a period of 18 years. Time trends of all indicators have been descriptively analysed. Statistical associations between time trends and between involuntary and admissions economic indicators were analysed by regression models. All annual involuntary commitment rates have increased, judicial ordered physical restraint measures particularly strongly (848%). The rate of judicial rejections of applied involuntary measures showed the lowest increase. On the other hand, quotas of involuntary admissions remained stable. In former East Germany, the involuntary admission rates are only a third of those in the former West Germany. Results of regression analyses indicate an excess increase of physical coercive measures in psychiatric hospitals in relation to the increase of psychiatric admissions. In former East Germany the rate of involuntary admissions at the federal state level is negatively correlated with the average gross income. The continuous increase of coercive psychiatric measures in consequence to the change in the Guardianship law suggests that this change has influenced the practice. The differences at federal and state levels, and the sharper rise in the former East Germany by lower rates in comparison to the former West Germany need an explanation, as well as the fact that the rate of involuntary admissions is associated at least in the former East Germany with economic conditions. © Georg Thieme Verlag KG Stuttgart · New York.

Muscular control of a learned movement: the speed control system hypothesis.

PubMed

Enoka, R M

1983-01-01

The "speed control system" hypothesis, which represents an attempt to identify an invariant characteristic of learned movements, postulates that movements of variable extent are controlled by regulating the intensity of muscle contractions such that the contraction duration remains constant. The contingency set originally utilized to develop this hypothesis was expanded by examining a movement that was multidirectional and multiarticular, and executed by large muscle groups generating near maximum torques. The investigation focused on the techniques utilized by weightlifters to control lower extremity displacement during the initial phase of the double knee bend execution of the "clean" in Olympic weightlifting. The combination of the quantified muscle activity and the angular velocity, both about the knee joint, revealed a sequence of shortening-lengthening muscle contractions throughout the movement. The first two periods of net muscular activity, one extensor and the other flexor, were utilized to examine the movement for invariant characteristics. As predicted by the speed control system hypothesis, the duration of the first period of net muscle torque activity (extensor) did not vary significantly, for either group of subjects, over the relative loads examined. The duration of the second period of activity (resultant flexor muscle torque), however, was not constant across loads, and further, the direction of the change depended upon the level of expertise. The more capable lifters tended to increase the duration of the resultant flexor involvement while the less skilled athletes utilized the reverse strategy when the load was increased. Conversely, the intensity of the muscle activity for both groups of subjects and both the extensor and flexor periods covaried with load, as predicted by the hypothesis. The speed control system hypothesis, therefore, provided an appropriate explanation for the first component of the movement, the period of extensor dominated

Fiducial marker-based correction for involuntary motion in weight-bearing C-arm CT scanning of knees. Part I. Numerical model-based optimization

PubMed Central

Choi, Jang-Hwan; Fahrig, Rebecca; Keil, Andreas; Besier, Thor F.; Pal, Saikat; McWalter, Emily J.; Beaupré, Gary S.; Maier, Andreas

2013-01-01

Purpose: Human subjects in standing positions are apt to show much more involuntary motion than in supine positions. The authors aimed to simulate a complicated realistic lower body movement using the four-dimensional (4D) digital extended cardiac-torso (XCAT) phantom. The authors also investigated fiducial marker-based motion compensation methods in two-dimensional (2D) and three-dimensional (3D) space. The level of involuntary movement-induced artifacts and image quality improvement were investigated after applying each method. Methods: An optical tracking system with eight cameras and seven retroreflective markers enabled us to track involuntary motion of the lower body of nine healthy subjects holding a squat position at 60° of flexion. The XCAT-based knee model was developed using the 4D XCAT phantom and the optical tracking data acquired at 120 Hz. The authors divided the lower body in the XCAT into six parts and applied unique affine transforms to each so that the motion (6 degrees of freedom) could be synchronized with the optical markers’ location at each time frame. The control points of the XCAT were tessellated into triangles and 248 projection images were created based on intersections of each ray and monochromatic absorption. The tracking data sets with the largest motion (Subject 2) and the smallest motion (Subject 5) among the nine data sets were used to animate the XCAT knee model. The authors defined eight skin control points well distributed around the knees as pseudo-fiducial markers which functioned as a reference in motion correction. Motion compensation was done in the following ways: (1) simple projection shifting in 2D, (2) deformable projection warping in 2D, and (3) rigid body warping in 3D. Graphics hardware accelerated filtered backprojection was implemented and combined with the three correction methods in order to speed up the simulation process. Correction fidelity was evaluated as a function of number of markers used (4–12) and

Optical induction of muscle contraction at the tissue scale through intrinsic cellular amplifiers.

PubMed

Yoon, Jonghee; Choi, Myunghwan; Ku, Taeyun; Choi, Won Jong; Choi, Chulhee

2014-08-01

The smooth muscle cell is the principal component responsible for involuntary control of visceral organs, including vascular tonicity, secretion, and sphincter regulation. It is known that the neurotransmitters released from nerve endings increase the intracellular Ca(2+) level in smooth muscle cells followed by muscle contraction. We herein report that femtosecond laser pulses focused on the diffraction-limited volume can induce intracellular Ca(2+) increases in the irradiated smooth muscle cell without neurotransmitters, and locally increased intracellular Ca(2+) levels are amplified by calcium-induced calcium-releasing mechanisms through the ryanodine receptor, a Ca(2+) channel of the endoplasmic reticulum. The laser-induced Ca(2+) increases propagate to adjacent cells through gap junctions. Thus, ultrashort-pulsed lasers can induce smooth muscle contraction by controlling Ca(2+), even with optical stimulation of the diffraction-limited volume. This optical method, which leads to reversible and reproducible muscle contraction, can be used in research into muscle dynamics, neuromuscular disease treatment, and nanorobot control. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effects of spinal mobilization with arm movements on shoulder muscle strengthening

PubMed Central

Seo, Youngjoon; Lee, Jaeseok; Han, Dongwook

2015-01-01

[Purpose] This study was performed to examine the immediate effects of spinal mobilization with arm movements (SMWAMs) for strengthening the shoulder muscles. [Subjects] The subjects of this study were 12 healthy male students who were studying at S University, Busan City. They had no musculoskeletal disease, or upper congenital malformation, and had no history of surgery or neurological disease. [Methods] The SMWAMs were performed on the 4th cervical vertebra (C4). For stimulation of the 5th cervical nerve, the spinous process of the C4 was pushed to the left and held in place. Then the arm was abducted to the point where spinous process was felt, and the range of abduction was examined. Subsequently, the abduction movement was repeated 10 times to the same point, and the gliding of C4 was held until the arm returned to the starting position. During the treatment, the head and the trunk were held in the correct posture. [Results] After SMWAMs had been performed, the muscular strength of shoulder flexion, extension and adduction significantly increased. [Conclusion] In our opinion, the SMWAMs are a very useful method for correcting spinal malalignment, and for stimulating the joint mechanoreceptors without the risks of manipulation. SMWAM is a valuable therapy method that can complement the demerits of mobilization. PMID:25642026

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

PubMed Central

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

2014-01-01

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. PMID:24412204

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.

Gravitational and Dynamic Components of Muscle Torque Underlie Tonic and Phasic Muscle Activity during Goal-Directed Reaching.

PubMed

Olesh, Erienne V; Pollard, Bradley S; Gritsenko, Valeriya

2017-01-01

Human reaching movements require complex muscle activations to produce the forces necessary to move the limb in a controlled manner. How gravity and the complex kinetic properties of the limb contribute to the generation of the muscle activation pattern by the central nervous system (CNS) is a long-standing and controversial question in neuroscience. To tackle this issue, muscle activity is often subdivided into static and phasic components. The former corresponds to posture maintenance and transitions between postures. The latter corresponds to active movement production and the compensation for the kinetic properties of the limb. In the present study, we improved the methodology for this subdivision of muscle activity into static and phasic components by relating them to joint torques. Ten healthy subjects pointed in virtual reality to visual targets arranged to create a standard center-out reaching task in three dimensions. Muscle activity and motion capture data were synchronously collected during the movements. The motion capture data were used to calculate postural and dynamic components of active muscle torques using a dynamic model of the arm with 5 degrees of freedom. Principal Component Analysis (PCA) was then applied to muscle activity and the torque components, separately, to reduce the dimensionality of the data. Muscle activity was also reconstructed from gravitational and dynamic torque components. Results show that the postural and dynamic components of muscle torque represent a significant amount of variance in muscle activity. This method could be used to define static and phasic components of muscle activity using muscle torques.

Gravitational and Dynamic Components of Muscle Torque Underlie Tonic and Phasic Muscle Activity during Goal-Directed Reaching

PubMed Central

Olesh, Erienne V.; Pollard, Bradley S.; Gritsenko, Valeriya

2017-01-01

Human reaching movements require complex muscle activations to produce the forces necessary to move the limb in a controlled manner. How gravity and the complex kinetic properties of the limb contribute to the generation of the muscle activation pattern by the central nervous system (CNS) is a long-standing and controversial question in neuroscience. To tackle this issue, muscle activity is often subdivided into static and phasic components. The former corresponds to posture maintenance and transitions between postures. The latter corresponds to active movement production and the compensation for the kinetic properties of the limb. In the present study, we improved the methodology for this subdivision of muscle activity into static and phasic components by relating them to joint torques. Ten healthy subjects pointed in virtual reality to visual targets arranged to create a standard center-out reaching task in three dimensions. Muscle activity and motion capture data were synchronously collected during the movements. The motion capture data were used to calculate postural and dynamic components of active muscle torques using a dynamic model of the arm with 5 degrees of freedom. Principal Component Analysis (PCA) was then applied to muscle activity and the torque components, separately, to reduce the dimensionality of the data. Muscle activity was also reconstructed from gravitational and dynamic torque components. Results show that the postural and dynamic components of muscle torque represent a significant amount of variance in muscle activity. This method could be used to define static and phasic components of muscle activity using muscle torques. PMID:29018339

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…

MRI Evidence of Cerebellar and Extraocular Muscle Atrophy Differently Contributing to Eye Movement Abnormalities in SCA2 and SCA28 Diseases.

PubMed

Politi, Letterio Salvatore; Bianchi Marzoli, Stefania; Godi, Claudia; Panzeri, Marta; Ciasca, Paola; Brugnara, Gianluca; Castaldo, Anna; Di Bella, Daniela; Taroni, Franco; Nanetti, Lorenzo; Mariotti, Caterina

2016-05-01

Spinocerebellar ataxias type 2 and 28 (SCA2, SCA28) are autosomal dominant disorders characterized by progressive cerebellar and oculomotor abnormalities. We aimed to investigate cerebellar, brainstem, and extraocular muscle involvement in the mitochondrial SCA28 disease compared with SCA2. We obtained orbital and brain 1.5 T-magnetic resonance images (MRI) in eight SCA28 subjects, nine SCA2, and nine age-matched healthy subjects. Automated segmentation of cerebellum and frontal lobe was performed using Freesurfer software. Manual segmentations for midbrain, pons, and extraocular muscles were performed using OsiriX. Eye movement abnormalities in SCA2 subjects were characterized by slow horizontal saccades. Subjects with SCA28 variably presented hypometric saccades, saccadic horizontal pursuit, impaired horizontal gaze holding, and superior eyelid ptosis. Quantitative brain MRI demonstrated that cerebellar and pons volumes were significantly reduced in both SCA2 and SCA28 subjects compared with controls (P < 0.03), and in SCA2 subjects compared with SCA28 (P < 0.01). Midbrain and frontal lobe volumes were also significantly reduced in SCA2 compared to controls (P < 0.03), whereas these volumes did not differ between SCA2 and SCA28 and between SCA28 and control subjects. The extraocular muscle areas were 37% to 48% smaller in SCA28 subjects compared with controls (P < 0.002), and 14% to 36% smaller compared with SCA2 subjects (P < 0.03). Extraocular muscle areas did not differ between SCA2 and controls. Our MRI findings support the hypothesis of different cerebellar and extraocular myopathic contributions in the eye movement abnormalities in SCA2 and SCA28 diseases. In SCA28, a myopathic defect selectively involving the extraocular muscles supports a specific impairment of mitochondrial energy metabolism.

Turnover and organizational performance: a comparative analysis of the effects of voluntary, involuntary, and reduction-in-force turnover.

PubMed

McElroy, J C; Morrow, P C; Rude, S N

2001-12-01

Data were collected from 31 regional subunits of a national financial services company to examine differential effects of 3 types of turnover (voluntary, involuntary, and reduction-in-force) on measures of organizational subunit performance. Although each form of turnover exhibited adverse effects on subunit performance when examined separately, partial correlation results revealed greater and more pervasive adverse effects for reduction-in-force turnover (i.e., downsizing) in comparison with the effects of voluntary and involuntary turnover. The results confirm the negative effects of downsizing, suggesting the need to move beyond the traditional voluntary-involuntary classification scheme used in turnover research.

Does retrieval intentionality really matter? Similarities and differences between involuntary memories and directly and generatively retrieved voluntary memories.

PubMed

Barzykowski, Krystian; Staugaard, Søren Risløv

2016-08-01

Theories of autobiographical memory distinguish between involuntary and voluntary retrieval as a consequence of conscious intention (i.e., wanting to remember). Another distinction can be made between direct and generative retrieval, which reflects the effort involved (i.e., trying to remember). However, it is unclear how intention and effort interacts. For example, involuntary memories and directly retrieved memories have been used interchangeably in the literature to refer to the same phenomenon of effortless, non-strategic retrieval. More recent theoretical advances suggest that they are separate types of retrieval, one unintentional (involuntary), another intentional and effortless (direct voluntary retrieval), and a third intentional and effortful (generative voluntary retrieval). Whether this also entails differing phenomenological characteristics, such as vividness, rehearsal, or emotional valence, has not been previously investigated. In the current study, participants reported memories in an experimental paradigm designed to elicit voluntary and involuntary memories and rated them on a number of characteristics. If intention affects the retrieval process, then we should expect differences between the characteristics of involuntary and directly retrieved memories. The results imply that retrieval intention seems to differentiate how a memory appears in a person's mind. Furthermore, we argue that these differences in part could result from differences in encoding and consolidation. © 2015 The British Psychological Society.

Noninvasive analysis of human neck muscle function

NASA Technical Reports Server (NTRS)

Conley, M. S.; Meyer, R. A.; Bloomberg, J. J.; Feeback, D. L.; Dudley, G. A.

1995-01-01

STUDY DESIGN. Muscle use evoked by exercise was determined by quantifying shifts in signal relaxation times of T2-weighted magnetic resonance images. Images were collected at rest and after exercise at each of two intensities (moderate and intense) for each of four head movements: 1) extension, 2) flexion, 3) rotation, and 4) lateral flexion. OBJECTIVE. This study examined the intensity and pattern of neck muscle use evoked by various movements of the head. The results will help elucidate the pathophysiology, and thus methods for treating disorders of the cervical musculoskeletal system. SUMMARY OF BACKGROUND DATA. Exercise-induced contrast shifts in T2 has been shown to indicate muscle use during the activity. The noninvasive nature of magnetic resonance imaging appears to make it an ideal approach for studying the function of the complex neuromuscular system of the neck. METHODS. The extent of T2 increase was examined to gauge how intensely nine different neck muscles or muscle pairs were used in seven subjects. The absolute and relative cross-sectional area of muscle showing a shift in signal relaxation was assessed to infer the pattern of use among and within individual neck muscles or muscle pairs. RESULTS. Signal relaxation increased with exercise intensity for each head movement. The absolute and relative cross-sectional area of muscle showing a shift in signal relaxation also increased with exercise load. Neck muscles or muscle pairs extensively used to perform each head movement were: extension--semispinalis capitis and cervicis and splenius capitis; flexion--sternocleidomastoid and longus capitis and colli; rotation--splenius capitis, levator scapulae, scalenus, semispinalis capitis ipsilateral to the rotation, and sternocleidomastoid contralateral; and lateral flexion--sternocleidomastoid CONCLUSION. The results of this study, in part, agree with the purported functions of neck muscles derived from anatomic location. This also was true for the few

32 CFR Appendix D to Part 113 - Sample DD Form 2654, “Involuntary Allotment Notice and Processing”

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 1 2010-07-01 2010-07-01 false Sample DD Form 2654, âInvoluntary Allotment Notice and Processingâ D Appendix D to Part 113 National Defense Department of Defense OFFICE OF THE..., App. D Appendix D to Part 113—Sample DD Form 2654, “Involuntary Allotment Notice and Processing...

Does the cerebellum initiate movement?

PubMed

Thach, W T

2014-02-01

Opinion is divided on what the exact function of the cerebellum is. Experiments are summarized that support the following views: (1) the cerebellum is a combiner of multiple movement factors; (2) it contains anatomically fixed permanent focal representation of individual body parts (muscles and segments) and movement modes (e.g., vestibular driven vs. cognitive driven); (3) it contains flexible changing representations/memory of physical properties of the body parts including muscle strength, segment inertia, joint viscosity, and segmental interaction torques (dynamics); (4) it contains mechanisms for learning and storage of the properties in item no. 3 through trial-and-error practice; (5) it provides for linkage of body parts, motor modes, and motordynamics via the parallel fiber system; (6) it combines and integrates the many factors so as to initiate coordinated movements of the many body parts; (7) it is thus enabled to play the unique role of initiating coordinated movements; and (8) this unique causative role is evidenced by the fact that: (a) electrical stimulation of the cerebellum can initiate compound coordinated movements; (b) in naturally initiated compound movements, cerebellar discharge precedes that in downstream target structures such as motor cerebral cortex; and (c) cerebellar ablation abolishes the natural production of compound movements in the awake alert individuals.

Extraocular muscle architecture in hawks and owls.

PubMed

Plochocki, Jeffrey H; Segev, Tamar; Grow, Wade; Hall, Margaret I

2018-02-06

A complete and accurate understanding of extraocular muscle function is important to the veterinary care of the avian eye. This is especially true for birds of prey, which rely heavily on vision for survival and yet are prone to ocular injury and disease. To better understand the function of extraocular muscles in birds of prey, we studied extraocular muscle architecture grossly and histologically. This sample was composed of two each of the following species: red-tailed hawk (Buteo jamaicensis), Harris's hawk (Parabuteo unicinctus), great horned owl (Bubo virginianus), and barn owl (Tyto alba). All extraocular muscles were dissected and weighed. To analyze muscle fiber architecture, the superior oblique and quadratus muscles were dissected, weighed, and sectioned at 5 μm thickness in the transverse plane. We calculated the physiologic cross-sectional area and the ratio of muscle mass to predicted effective maximum tetanic tension. Hawk and owl extraocular muscles exhibit significant physiological differences that play roles in ocular movements and closure of the nictitating membrane. Owls, which do not exhibit extraocular movement, have muscle architecture suited to stabilize the position of a massive, tubular eye that protrudes significantly from the orbit. Hawks, which have a more globose eye that is largely contained within the orbit, do not require as much muscular stability and instead have muscle architecture that facilitates rapid eye movement. © 2018 American College of Veterinary Ophthalmologists.

[The influence of non-invasive electrical stimulation of the spinal cord on the locomotor function of patients presenting with movement disorders of central genesis].

PubMed

Balykin, M V; Yakupov, R N; Mashin, V V; Kotova, E Yu; Balykin, Yu M; Gerasimenko, Yu P

The objective of the present study was to evaluate the influence of non-invasive (transcutaneous) electrical spinal cord stimulation on the locomotor function of the patients suffering from movement disorders. The study involved 10 patients of both sexes at the age from 32 to 70 years (including 40% of men and 60% of women) presenting with the compromised locomotor function of varying severity associated with the disturbances of cerebral blood circulation caused either by an injury to the brain and spinal cord or by stroke. The transcutaneous electrical spinal cord stimulation was applied using different frequency regimes with the placement of the electrodes in the projection onto the region of TXI-TXII vertebrae. The active factors were bipolar electrical stimuli 0.5 ms in duration; the current strength was chosen for each patient on an individual basis taking into consideration its threshold level. Electromyograms and evoked motor responses of selected muscles, viz. m. rectus femoris, m.biceps femoris, m. tibialis anterior, and m.gastrocnemius were recorded with the use of the 'Neuro-MVP-8 eight-channel electromyography' ('Neurosoft', Russia). The data obtained give evidence that the stimulation of the spinal cord with a frequency of 1 Hz induces reflectory responses with monosynaptic and polysynaptic components in the muscles of the lower extremities, with the thresholds of these responses being significantly higher in the patients presenting with serious neurological problems. Stimulation with the frequencies of 5 and 30 Hz caused in the patients with paresis the involuntary movement of the legs the characteristics of which were similar to those of the locomotor movements. It has been demonstrated that the application of transcutaneous electrical spinal cord stimulation leads to increased excitability of the lumbar spinal neural structures of the patients. The study has shown the possibility of regulation of the locomotor functions in the patients presenting

Involuntary sterilization among HIV-positive Garifuna women from Honduras seeking asylum in the United States: Two case reports.

PubMed

Atkinson, Holly G; Ottenheimer, Deborah

2018-05-01

Voluntary sterilization is one of the most widely used forms of contraception by women worldwide; however, involuntary sterilization is considered a violation of multiple human rights and grounds for asylum in the United States. Women have been disproportionately affected by this practice. We report two cases of involuntary sterilization in HIV-positive Garifuna women from Honduras who sought asylum in America and were medically evaluated at the request of their attorneys. Key lessons can be drawn from these cases with regard to the importance of medical evaluations in establishing persecution. These include the need for a detailed account of the events surrounding sterilization, radiologic proof of tubal blockage if at all possible, and confirmation of significant and enduring mental distress as a result of the involuntary sterilization. Immigration attorneys and medical evaluators need to be attuned to the possibility of a history of involuntary sterilization among at risk women seeking asylum in the United States. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Cholinergic Enhancement Increases the Effects of Voluntary Attention but Does Not Affect Involuntary Attention

PubMed Central

Rokem, Ariel; Landau, Ayelet N; Garg, Dave; Prinzmetal, William; Silver, Michael A

2010-01-01

Voluntary visual spatial attention can be allocated in a goal-oriented manner to locations containing behaviorally relevant information. In contrast, involuntary attention is automatically captured by salient events. Allocation of attention is known to be modulated by release of the neurotransmitter acetylcholine (ACh) in cerebral cortex. We used an anti-predictive spatial cueing task to assess the effects of pharmacological enhancement of cholinergic transmission on behavioral measures of voluntary and involuntary attention in healthy human participants. Each trial began with the presentation of a cue in a peripheral location. In 80% of the trials, a target then appeared in a location opposite the cue. In the remaining 20% of trials, the target appeared in the cue location. For trials with short stimulus onset asynchrony (SOA) between cue and target, involuntary capture of attention resulted in shorter reaction times (RTs) to targets presented at the cue location. For long SOA trials, allocation of voluntary attention resulted in the opposite pattern: RTs were shorter when the target appeared in the expected (opposite) location. Each subject participated in two sessions: one in which the cholinesterase inhibitor donepezil was administered to increase synaptic ACh levels and one in which placebo was administered. Donepezil selectively improved performance (reduced RT) for long SOA trials in which targets appeared in the expected location. Thus, cholinergic enhancement augments the benefits of voluntary attention but does not affect involuntary attention, suggesting that they rely on different neurochemical mechanisms. PMID:20811340

Sleep-related movement disorders.

PubMed

Merlino, Giovanni; Gigli, Gian Luigi

2012-06-01

Several movement disorders may occur during nocturnal rest disrupting sleep. A part of these complaints is characterized by relatively simple, non-purposeful and usually stereotyped movements. The last version of the International Classification of Sleep Disorders includes these clinical conditions (i.e. restless legs syndrome, periodic limb movement disorder, sleep-related leg cramps, sleep-related bruxism and sleep-related rhythmic movement disorder) under the category entitled sleep-related movement disorders. Moreover, apparently physiological movements (e.g. alternating leg muscle activation and excessive hypnic fragmentary myoclonus) can show a high frequency and severity impairing sleep quality. Clinical and, in specific cases, neurophysiological assessments are required to detect the presence of nocturnal movement complaints. Patients reporting poor sleep due to these abnormal movements should undergo non-pharmacological or pharmacological treatments.

Long-term consequences of youth volunteering: Voluntary versus involuntary service.

PubMed

Kim, Jinho; Morgül, Kerem

2017-09-01

Despite the renewed interest in youth volunteering in recent years, there remain major gaps in our knowledge of its consequences. Drawing data from the National Longitudinal Study of Adolescent to Adult Health, we examine the long-term effects of youth volunteering on the civic and personal aspects of volunteers' lives. Our results suggest that youth volunteering has a positive return on adult volunteering only when it is voluntary, and that net of contextual factors neither voluntary nor involuntary youth service has a significant effect on adult voting. Regarding personal outcomes, our findings indicate that the psychological benefits of youth volunteering accrue only to voluntary participants, whereas both voluntary and involuntary youth service are positively associated with educational attainment and earnings in young adulthood. Taken together, these results lend support to the case for youth volunteer programs, though the civic benefits of these programs appear to be less dramatic than generally suggested. Copyright © 2017 Elsevier Inc. All rights reserved.

Workforce Downsizing and Restructuring in the Department of Defense: The Voluntary Separation Incentive Payment Program Versus Involuntary Separation

DTIC Science & Technology

2016-01-01

Workforce Downsizing and Restructuring in the Department of Defense The Voluntary Separation Incentive Payment Program Versus Involuntary...Voluntary Separation Incentive Payment (VSIP). The purposes of this research are to place VSIP in context relative to involuntary separation, determine...5 CHAPTER TWO Review of Severance Pay, Voluntary Separation Incentive Pay, and Voluntary

Gravitoinertial force level influences arm movement control

NASA Technical Reports Server (NTRS)

Fisk, J.; Lackner, J. R.; DiZio, P.

1993-01-01

1. The ability to move the forearm between remembered elbow joint angles immediately after rapid increases or decreases of the background gravitoinertial force (G) level was measured. The movements had been well-practiced in a normal 1G environment before the measurements in high-(1.8G) and low-force (0G) environments. The forearm and upper arm were always unsupported to maximize the influence of altered G-loading and to minimize extraneous cues about arm position. 2. Horizontal and vertical movement planes were studied to measure the effects of varying the G load in the movement plane within a given G background. Rapid and slow movements were studied to assess the role of proprioceptive feedback. 3. G level did not affect the amplitude of rapid movements, indicating that subjects were able to plan and to generate appropriate motor commands for the new G loading of the arm. The amplitude of slow movements was affected by G level, indicating that proprioceptive feedback is influenced by G level. 4. The effects of G level were similar for horizontal and vertical movements, indicating that proprioceptive information from supporting structures, such as the shoulder joint and muscles, had a role in allowing generation of the appropriate motor commands. 5. The incidence and size of dynamic overshoots were greater in 0G and for rapid movements. This G-related change in damping suggests a decrease in muscle spindle activity in 0G. A decrease in muscle spindle activity in 0G and an increase in 1.8G are consistent with the results of our prior studies on the tonic vibration reflex, locomotion, and perception of head movement trajectory in varying force backgrounds.

Thoughts on selected movement disorder terminology and a plea for clarity.

PubMed

Walker, Ruth H

2013-01-01

Description of the phenomenology of movement disorders requires precise and accurate terminology. Many of the terms that have been widely used in the literature are imprecise and open to interpretation. An examination of these terms and the assumptions implicit in their usage is important to improve communication and hence the definition, diagnosis, and treatment of movement disorders. I recommend that the term dyskinesia should be used primarily in the settings of Parkinson's disease and tardive dyskinesia, in which its clinical implications are relatively clear; it should not be used in other situations where a precise description could more usefully facilitate diagnosis and treatment. In general dyskinesia should be used in the singular form. Extrapyramidal is based upon obsolete anatomical concepts, is uninformative, and should be discarded. The term abnormal involuntary movements (AIMs) is similarly vague and uninformative, although is unlikely to be eliminated from the psychiatric literature. Movement disorder neurologists as teachers, clinicians, article reviewers, and journal editors have the responsibility to educate our colleagues regarding appropriate usage and the importance of employing correct descriptors.

Losing dexterity: patterns of impaired coordination of finger movements in musician’s dystonia

PubMed Central

Furuya, Shinichi; Tominaga, Kenta; Miyazaki, Fumio; Altenmüller, Eckart

2015-01-01

Extensive training can bring about highly-skilled action, but may also impair motor dexterity by producing involuntary movements and muscular cramping, as seen in focal dystonia (FD) and tremor. To elucidate the underlying neuroplastic mechanisms of FD, the present study addressed the organization of finger movements during piano performance in pianists suffering from the condition. Principal component (PC) analysis identified three patterns of fundamental joint coordination constituting finger movements in both patients and controls. The first two coordination patterns described less individuated movements between the “dystonic” finger and key-striking fingers for patients compared to controls. The third coordination pattern, representing the individuation of movements between the middle and ring fingers, was evident during a sequence of strikes with these fingers in controls, which was absent in the patients. Consequently, rhythmic variability of keystrokes was more pronounced during this sequence of strikes for the patients. A stepwise multiple-regression analysis further identified greater variability of keystrokes for individuals displaying less individuated movements between the affected and striking fingers. The findings suggest that FD alters dexterous joint coordination so as to lower independent control of finger movements, and thereby degrades fine motor control. PMID:26289433

Effect of cooling on thixotropic position-sense error in human biceps muscle.

PubMed

Sekihara, Chikara; Izumizaki, Masahiko; Yasuda, Tomohiro; Nakajima, Takayuki; Atsumi, Takashi; Homma, Ikuo

2007-06-01

Muscle temperature affects muscle thixotropy. However, it is unclear whether changes in muscle temperature affect thixotropic position-sense errors. We studied the effect of cooling on thixotropic position-sense errors induced by short-length muscle contraction (hold-short conditioning) in the biceps of 12 healthy men. After hold-short conditioning of the right biceps muscle in a cooled (5.0 degrees C) or control (36.5 degrees C) environment, subjects perceived greater extension of the conditioned forearm at 5.0 degrees C. The angle differences between the two forearms following hold-short conditioning of the right biceps muscle in normal or cooled conditions were significantly different (-3.335 +/- 1.680 degrees at 36.5 degrees C vs. -5.317 +/- 1.096 degrees at 5.0 degrees C; P=0.043). Induction of a tonic vibration reflex in the biceps muscle elicited involuntary forearm elevation, and the angular velocities of the elevation differed significantly between arms conditioned in normal and cooled environments (1.583 +/- 0.326 degrees /s at 36.5 degrees C vs. 3.100 +/- 0.555 degrees /s at 5.0 degrees C, P=0.0039). Thus, a cooled environment impairs a muscle's ability to provide positional information, potentially leading to poor muscle performance.

Automaticity in reading and the Stroop task: testing the limits of involuntary word processing.

PubMed

Brown, Tracy L; Joneleit, Kelly; Robinson, Cathy S; Brown, Carli Rose

2002-01-01

We investigated the parameters of involuntary word reading in the Stroop task in 7 experiments. Experiments 1-4 varied response modality and the presence of congruent word trials in a test of the claim that presenting a Stroop color word with only one letter in the target color eliminates the Stroop effect. Experiments 5 and 6 addressed the roles of spatial attention and orthographic processing as possible mechanisms behind the reduction of Stroop effects with the single-letter format. Experiment 7 investigated the limits of involuntary reading under optimal conditions for selective processing of rectangular color patch targets. We found that the single-letter format reduced but never eliminated Stroop effects, spatial attention but not orthographic processing plays a role in the effect of the single-letter format, and word reading is not completely prevented even with austere presentation conditions. We conclude with a defense of the involuntariness criterion for automaticity in the Stroop task, particularly when word reading is viewed in the context of a skilled performance.

Qualitative exploration of stakeholders' perspectives of involuntary admission under the Mental Health Act 2001 in Ireland.

PubMed

Smyth, Siobhán; Casey, Dympna; Cooney, Adeline; Higgins, Agnes; McGuinness, David; Bainbridge, Emma; Keys, Mary; Georgieva, Irina; Brosnan, Liz; Beecher, Claire; Hallahan, Brian; McDonald, Colm; Murphy, Kathy

2017-12-01

There is international interest in, and continued concern about, the potential long-term impact of involuntary admission to psychiatric institutions, and the effect this coercive action has on a person's well-being and human rights. Involuntary detention in hospital remains a controversial process that involves stakeholders with competing concerns and who often describe negative experiences of the process, which can have long-lasting effects on the therapeutic relationship with service users. The aim of the present study was to explore the perspectives of key stakeholders involved in the involuntary admission and detention of people under the Mental Health Act 2001 in Ireland. Focus groups were used to collect data. Stakeholders interviewed were service users, relatives, general practitioners, psychiatrists, mental health nurses, solicitors, tribunal members, and police. Data were analysed using a general inductive approach. Three key categories emerged: (i) getting help; (ii) detention under the Act; and (iii) experiences of the tribunal process. This research highlights gaps in information and uncertainty about the involuntary admission process for stakeholders, but particularly for service users who are most affected by inadequate processes and supports. Mental health law has traditionally focussed on narrower areas of detention and treatment, but human rights law requires a greater refocussing on supporting service users to ensure a truly voluntary approach to care. The recent human rights treaty, the UN Convention on the Rights of Persons with Disabilities, is to guarantee a broad range of fundamental rights, such as liberty and integrity, which can be affected by coercive processes of involuntary admission and treatment. © 2016 Australian College of Mental Health Nurses Inc.

26 CFR 1.1033(c)-1 - Disposition of excess property within irrigation project deemed to be involuntary conversion.

Code of Federal Regulations, 2010 CFR

2010-04-01

... project deemed to be involuntary conversion. 1.1033(c)-1 Section 1.1033(c)-1 Internal Revenue INTERNAL... Nontaxable Exchanges § 1.1033(c)-1 Disposition of excess property within irrigation project deemed to be... project or division shall be treated as an involuntary conversion to which the provisions of section 1033...

Muscle wasting in cancer: the role of mitochondria.

PubMed

Argilés, Josep M; López-Soriano, Francisco J; Busquets, Silvia

2015-05-01

The aim of the present review is to examine the impact of mitochondrial dysfunction in cancer cachexia. Oxidative pathways are altered in this tissue during muscle wasting and this seems to be a consequence of mitochondrial abnormalities that include altered morphology and function, decreased ATP synthesis and uncoupling. An alteration of energy balance is the immediate cause of cachexia. Both alterations in energy intake and expenditure are responsible for the wasting syndrome associated with different types of pathological conditions, such as cancer. Different types of molecular mechanisms contribute to energy expenditure and, therefore, involuntary body weight loss, one of which is mitochondrial dysfunction.

Dynamic model of the octopus arm. I. Biomechanics of the octopus reaching movement.

PubMed

Yekutieli, Yoram; Sagiv-Zohar, Roni; Aharonov, Ranit; Engel, Yaakov; Hochner, Binyamin; Flash, Tamar

2005-08-01

The octopus arm requires special motor control schemes because it consists almost entirely of muscles and lacks a rigid skeletal support. Here we present a 2D dynamic model of the octopus arm to explore possible strategies of movement control in this muscular hydrostat. The arm is modeled as a multisegment structure, each segment containing longitudinal and transverse muscles and maintaining a constant volume, a prominent feature of muscular hydrostats. The input to the model is the degree of activation of each of its muscles. The model includes the external forces of gravity, buoyancy, and water drag forces (experimentally estimated here). It also includes the internal forces generated by the arm muscles and the forces responsible for maintaining a constant volume. Using this dynamic model to investigate the octopus reaching movement and to explore the mechanisms of bend propagation that characterize this movement, we found the following. 1) A simple command producing a wave of muscle activation moving at a constant velocity is sufficient to replicate the natural reaching movements with similar kinematic features. 2) The biomechanical mechanism that produces the reaching movement is a stiffening wave of muscle contraction that pushes a bend forward along the arm. 3) The perpendicular drag coefficient for an octopus arm is nearly 50 times larger than the tangential drag coefficient. During a reaching movement, only a small portion of the arm is oriented perpendicular to the direction of movement, thus minimizing the drag force.

Robotic Powered Transfer Mechanism modeling on Human Muscle Structure

NASA Astrophysics Data System (ADS)

Saito, Yukio

It is considered in engineering that one power source can operate one joint. However, support movement mechanism of living organism is multi joint movement mechanism. Considerably different from mechanical movement mechanism, two pairs of uni-articular muscles and a pair of bi-articular muscles are involved in it. In leg, movements observed in short run including leg idling, heel contact and toeing are operated by bi-articular muscles of the thigh showing strong legs to support body weight. Pursuit of versatility in welfare robot brings its comparison with conventional machinery or industrial robot to the fore. Request for safety and technology allowing elderly people to operate the robot is getting stronger in the society. The robot must be safe when it is used together with other welfare equipment and simpler system avoiding difficult operation has to be constructed. Appearance of recent care and assistance robot is getting similar to human arm in comparison with industrial robot. Being easily able to imagine from industrial robot, mid-heavyweight articulated robot to support 60-70kgf combined with large output motor and reduction gears is next to impossible to be installed in the bath room. This research indicated that upper limb arm and lower limb thigh of human and animals are holding coalitional muscles and movement of uni-artcular muscle and bi-articular muscle conjure the image of new actuators.

Potential of M-Wave Elicited by Double Pulse for Muscle Fatigue Evaluation in Intermittent Muscle Activation by Functional Electrical Stimulation for Motor Rehabilitation

PubMed Central

Miura, Naoto; Watanabe, Takashi

2016-01-01

Clinical studies on application of functional electrical stimulation (FES) to motor rehabilitation have been increasing. However, muscle fatigue appears early in the course of repetitive movement production training by FES. Although M-wave variables were suggested to be reliable indices of muscle fatigue in long lasting constant electrical stimulation under the isometric condition, the ability of M-wave needs more studies under intermittent stimulation condition, because the intervals between electrical stimulations help recovery of muscle activation level. In this paper, M-waves elicited by double pulses were examined in muscle fatigue evaluation during repetitive movements considering rehabilitation training with surface electrical stimulation. M-waves were measured under the two conditions of repetitive stimulation: knee extension force production under the isometric condition and the dynamic movement condition by knee joint angle control. Amplitude of M-wave elicited by the 2nd pulse of a double pulse decreased during muscle fatigue in both measurement conditions, while the change in M-waves elicited by single pulses in a stimulation burst was not relevant to muscle fatigue in repeated activation with stimulation interval of 1 s. Fatigue index obtained from M-waves elicited by 2nd pulses was suggested to provide good estimation of muscle fatigue during repetitive movements with FES. PMID:27110556

Conversations, coping, & connectedness: a qualitative study of women who have experienced involuntary pregnancy loss.

PubMed

Van, Paulina

2012-01-01

The purpose of this qualitative study was to describe processes and strategies used by women to cope after pregnancy loss. Twenty women with a history of involuntary pregnancy loss were interviewed. All of the women were in the last month of a subsequent pregnancy, married or partnered, and most were EuroAmerican or Asian American and had completed college. Taped interviews, fieldnotes, and analytical notes were transcribed then subsequently coded and developed in individual or team sessions. Construction and confirmation of the categories and related themes derived from the data was a collaborative process. Three themes were revealed that described the coping behaviors used by the women: being myself, connecting with others, and avoiding and pretending. The core concept of connectedness and coping after involuntary pregnancy loss was further validated in this study. The purpose of this study was to describe processes and strategies that facilitate coping for 20 women, pregnant subsequent to an involuntary pregnancy loss (IPL). Involuntary pregnancy loss (IPL) refers to miscarriages, ectopic pregnancies, fetal deaths, and stillbirths (Van & Meleis, 2003). This current study was designed to replicate two prior qualitative studies, with African-American women, by the author (Patterson, 2000; Van, 2001). Based on the author's previous work, a theoretical framework entitled "A Model of Living with Grief after Pregnancy Loss" was constructed (Patterson, 2000). For the current study, a more diverse sample was used to potentially expand the applicability of the Model of Living with Grief after Pregnancy Loss to women who are of races other than African American.

Voluntary and involuntary ligature of the bile duct in iatrogenic injuries: a nonadvisable approach.

PubMed

Mercado, Miguel Angel; Chan, Carlos; Jacinto, Juan Carlos; Sanchez, Norberto; Barajas, Alexandra

2008-06-01

Bile duct injuries related to laparoscopic and/or open cholecystectomy are a frequent finding and require surgical treatment. Complete obstruction is due to either intentionally or unintentionally placed ligatures or clips. The intentional application is usually performed to "facilitate identification of the duct by bile duct dilation." Considering that we are a national referral center for such injuries, we decided to analyze our cases of voluntary and involuntary duct ligation after iatrogenic bile duct injury. We reviewed the files of patients with voluntary or involuntary bile duct ligation. Results of preoperative evaluation of the ducts, operative treatment, and postoperative results were analyzed. A total of 413 patients were included. Forty-five patients presented with complete obstruction. In 15 cases, the ligature was intentional, and in 30 cases, occlusion was involuntary. Bile duct dilation (>10 mm) was demonstrated in one case of voluntary (6%) and three cases of involuntary ligations (10%). The remaining cases in both groups had no duct dilation and developed necrosis at the blinded duct and leakage proximal to the ligature, with different degrees of bilioperitoneum and/or biloma. In all cases, a Roux-en-Y hepatojejunostomy was performed. Bile duct ligature produces dilation in a very small number of patients (less than 10%) and usually produces necrosis of the blinded stump with subsequent bile leakage. Placement of a subhepatic drain and transference of the patient to a qualified center for reconstruction is the best approach if the primary surgeon is not able to do the repair.

Muscle activity during the golf swing.

PubMed

McHardy, A; Pollard, H

2005-11-01

In the right hands, the golf swing is a motion that inspires looks of awe from the public. It is a complex movement of the whole body to generate power to a golf ball to propel the ball great distances with accuracy. This movement relies on the coordinated sequence of muscle activation to produce a fluid and reproducible movement. This paper reviews the literature on golf swing related muscle activity. The phases of this activity are discussed with a view to assisting the practitioner in understanding the swing. Such understanding may help in the management of the injured golfer.

Patient-specific fibre-based models of muscle wrapping

PubMed Central

Kohout, J.; Clapworthy, G. J.; Zhao, Y.; Tao, Y.; Gonzalez-Garcia, G.; Dong, F.; Wei, H.; Kohoutová, E.

2013-01-01

In many biomechanical problems, the availability of a suitable model for the wrapping of muscles when undergoing movement is essential for the estimation of forces produced on and by the body during motion. This is an important factor in the Osteoporotic Virtual Physiological Human project which is investigating the likelihood of fracture for osteoporotic patients undertaking a variety of movements. The weakening of their skeletons makes them particularly vulnerable to bone fracture caused by excessive loading being placed on the bones, even in simple everyday tasks. This paper provides an overview of a novel volumetric model that describes muscle wrapping around bones and other muscles during movement, and which includes a consideration of how the orientations of the muscle fibres change during the motion. The method can calculate the form of wrapping of a muscle of medium size and visualize the outcome within tenths of seconds on commodity hardware, while conserving muscle volume. This makes the method suitable not only for educational biomedical software, but also for clinical applications used to identify weak muscles that should be strengthened during rehabilitation or to identify bone stresses in order to estimate the risk of fractures. PMID:24427519

Extending experiences of voluntary action by association

PubMed Central

Khalighinejad, Nima; Haggard, Patrick

2016-01-01

“Sense of agency” refers to the experience that links one’s voluntary actions to their external outcomes. It remains unclear whether this ubiquitous experience is hardwired, arising from specific signals within the brain’s motor systems, or rather depends on associative learning, through repeated cooccurrence of voluntary movements and their outcomes. To distinguish these two models, we asked participants to trigger a tone by a voluntary keypress action. The voluntary action was always associated with an involuntary movement of the other hand. We then tested whether the combination of the involuntary movement and tone alone might now suffice to produce a sense of agency, even when the voluntary action was omitted. Sense of agency was measured using an implicit marker based on time perception, namely a shift in the perceived time of the outcome toward the action that caused it. Across two experiments, repeatedly pairing an involuntary movement with a voluntary action induced key temporal features of agency, with the outcome now perceived as shifted toward the involuntary movement. This shift required involuntary movements to have been previously associated with voluntary actions. We show that some key aspects of agency may be transferred from voluntary actions to involuntary movements. An internal volitional signal is required for the primary acquisition of agency but, with repeated association, the involuntary movement in itself comes to produce some key temporal features of agency over the subsequent outcome. This finding may explain how humans can develop an enduring sense of agency in nonnatural cases, like brain–machine interfaces. PMID:27436902

Brain activation associated with eccentric movement: A narrative review of the literature.

PubMed

Perrey, Stéphane

2018-02-01

The movement occurring when a muscle exerts tension while lengthening is known as eccentric muscle action. Literature contains limited evidence on how our brain controls eccentric movement. However, how the cortical regions in the motor network are activated during eccentric muscle actions may be critical for understanding the underlying control mechanism of eccentric movements encountered in daily tasks. This is a novel topic that has only recently begun to be investigated through advancements in neuroimaging methods (electroencephalography, EEG; functional magnetic resonance imaging, fMRI). This review summarizes a selection of seven studies indicating mainly: longer time and higher cortical signal amplitude (EEG) for eccentric movement preparation and execution, greater magnitude of cortical signals with wider activated brain area (EEG, fMRI), and weaker brain functional connectivity (fMRI) between primary motor cortex (M1) and other cortical areas involved in the motor network during eccentric muscle actions. Only some differences among studies due to the forms of movement with overload were observed in the contralateral (to the active hand) M1 activity during eccentric movement. Altogether, the findings indicate an important challenge to the brain for controlling the eccentric movement. However, our understanding remains limited regarding the acute effects of eccentric exercise on cortical regions and their cooperation as functional networks that support motor functions. Further analysis and standardized protocols will provide deeper insights into how different cortical regions of the underlying motor network interplay with each other in increasingly demanding muscle exertions in eccentric mode.

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. 64.1512 Section 64.1512 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) MISCELLANEOUS RULES RELATING TO COMMON CARRIERS Interstate Pay-Per-Call and...

On the Origin of Muscle Synergies: Invariant Balance in the Co-activation of Agonist and Antagonist Muscle Pairs

PubMed Central

Hirai, Hiroaki; Miyazaki, Fumio; Naritomi, Hiroaki; Koba, Keitaro; Oku, Takanori; Uno, Kanna; Uemura, Mitsunori; Nishi, Tomoki; Kageyama, Masayuki; Krebs, Hermano Igo

2015-01-01

Investigation of neural representation of movement planning has attracted the attention of neuroscientists, as it may reveal the sensorimotor transformation essential to motor control. The analysis of muscle synergies based on the activity of agonist–antagonist (AA) muscle pairs may provide insight into such transformations, especially for a reference frame in the muscle space. In this study, we examined the AA concept using the following explanatory variables: the AA ratio, which is related to the equilibrium-joint angle, and the AA sum, which is associated with joint stiffness. We formulated muscle synergies as a function of AA sums, positing that muscle synergies are composite units of mechanical impedance. The AA concept can be regarded as another form of the equilibrium-point (EP) hypothesis, and it can be extended to the concept of EP-based synergies. We introduce, here, a novel tool for analyzing the neurological and motor functions underlying human movements and review some initial insights from our results about the relationships between muscle synergies, endpoint stiffness, and virtual trajectories (time series of EP). Our results suggest that (1) muscle synergies reflect an invariant balance in the co-activation of AA muscle pairs; (2) each synergy represents the basis for the radial, tangential, and null movements of the virtual trajectory in the polar coordinates centered on the specific joint at the base of the body; and (3) the alteration of muscle synergies (for example, due to spasticity or rigidity following neurological injury) results in significant distortion of endpoint stiffness and concomitant virtual trajectories. These results indicate that muscle synergies (i.e., the balance of muscle mechanical impedance) are essential for motor control. PMID:26636079

On the Origin of Muscle Synergies: Invariant Balance in the Co-activation of Agonist and Antagonist Muscle Pairs.

PubMed

Hirai, Hiroaki; Miyazaki, Fumio; Naritomi, Hiroaki; Koba, Keitaro; Oku, Takanori; Uno, Kanna; Uemura, Mitsunori; Nishi, Tomoki; Kageyama, Masayuki; Krebs, Hermano Igo

2015-01-01

Investigation of neural representation of movement planning has attracted the attention of neuroscientists, as it may reveal the sensorimotor transformation essential to motor control. The analysis of muscle synergies based on the activity of agonist-antagonist (AA) muscle pairs may provide insight into such transformations, especially for a reference frame in the muscle space. In this study, we examined the AA concept using the following explanatory variables: the AA ratio, which is related to the equilibrium-joint angle, and the AA sum, which is associated with joint stiffness. We formulated muscle synergies as a function of AA sums, positing that muscle synergies are composite units of mechanical impedance. The AA concept can be regarded as another form of the equilibrium-point (EP) hypothesis, and it can be extended to the concept of EP-based synergies. We introduce, here, a novel tool for analyzing the neurological and motor functions underlying human movements and review some initial insights from our results about the relationships between muscle synergies, endpoint stiffness, and virtual trajectories (time series of EP). Our results suggest that (1) muscle synergies reflect an invariant balance in the co-activation of AA muscle pairs; (2) each synergy represents the basis for the radial, tangential, and null movements of the virtual trajectory in the polar coordinates centered on the specific joint at the base of the body; and (3) the alteration of muscle synergies (for example, due to spasticity or rigidity following neurological injury) results in significant distortion of endpoint stiffness and concomitant virtual trajectories. These results indicate that muscle synergies (i.e., the balance of muscle mechanical impedance) are essential for motor control.

Involuntary Memories and Dissociative Amnesia: Assessing Key Assumptions in PTSD Research.

PubMed

Berntsen, Dorthe; Rubin, David C

2014-03-01

Autobiographical memories of trauma victims are often described as disturbed in two ways. First, the trauma is frequently re-experienced in the form of involuntary, intrusive recollections. Second, the trauma is difficult to recall voluntarily (strategically); important parts may be totally or partially inaccessible-a feature known as dissociative amnesia. These characteristics are often mentioned by PTSD researchers and are included as PTSD symptoms in the DSM-IV-TR (American Psychiatric Association, 2000). In contrast, we show that both involuntary and voluntary recall are enhanced by emotional stress during encoding. We also show that the PTSD symptom in the diagnosis addressing dissociative amnesia, trouble remembering important aspects of the trauma is less well correlated with the remaining PTSD symptoms than the conceptual reversal of having trouble forgetting important aspects of the trauma. Our findings contradict key assumptions that have shaped PTSD research over the last 40 years.

Involuntary Memories and Dissociative Amnesia: Assessing Key Assumptions in PTSD Research

PubMed Central

Berntsen, Dorthe; Rubin, David C.

2014-01-01

Autobiographical memories of trauma victims are often described as disturbed in two ways. First, the trauma is frequently re-experienced in the form of involuntary, intrusive recollections. Second, the trauma is difficult to recall voluntarily (strategically); important parts may be totally or partially inaccessible—a feature known as dissociative amnesia. These characteristics are often mentioned by PTSD researchers and are included as PTSD symptoms in the DSM-IV-TR (American Psychiatric Association, 2000). In contrast, we show that both involuntary and voluntary recall are enhanced by emotional stress during encoding. We also show that the PTSD symptom in the diagnosis addressing dissociative amnesia, trouble remembering important aspects of the trauma is less well correlated with the remaining PTSD symptoms than the conceptual reversal of having trouble forgetting important aspects of the trauma. Our findings contradict key assumptions that have shaped PTSD research over the last 40 years. PMID:25309832

Experimental masseter muscle pain alters jaw-neck motor strategy.

PubMed

Wiesinger, B; Häggman-Henrikson, B; Hellström, F; Wänman, A

2013-08-01

A functional integration between the jaw and neck regions has been demonstrated during normal jaw function. The effect of masseter muscle pain on this integrated motor behaviour in man is unknown. The aim of this study was to investigate the effect of induced masseter muscle pain on jaw-neck movements during a continuous jaw opening-closing task. Sixteen healthy men performed continuous jaw opening-closing movements to a target position, defined as 75% of the maximum jaw opening. Each subject performed two trials without pain (controls) and two trials with masseter muscle pain, induced with hypertonic saline as a single injection. Simultaneous movements of the mandible and the head were registered with a wireless optoelectronic three-dimensional recording system. Differences in movement amplitudes between trials were analysed with Friedman's test and corrected Wilcoxon matched pairs test. The head movement amplitudes were significantly larger during masseter muscle pain trials compared with control. Jaw movement amplitudes did not differ significantly between any of the trials after corrected Wilcoxon tests. The ratio between head and jaw movement amplitudes was significantly larger during the first pain trial compared with control. Experimental masseter muscle pain in humans affected integrated jaw-neck movements by increasing the neck component during continuous jaw opening-closing tasks. The findings indicate that pain can alter the strategy for jaw-neck motor control, which further underlines the functional integration between the jaw and neck regions. This altered strategy may have consequences for development of musculoskeletal pain in the jaw and neck regions. © 2012 European Federation of International Association for the Study of Pain Chapters.

Effects of thrust amplitude and duration of high velocity low amplitude spinal manipulation on lumbar muscle spindle responses to vertebral position and movement

PubMed Central

Cao, Dong-Yuan; Reed, William R.; Long, Cynthia R.; Kawchuk, Gregory N.; Pickar, Joel G.

2013-01-01

OBJECTIVE Mechanical characteristics of high velocity low amplitude spinal manipulations (HVLA-SM) can be variable. Sustained changes in peripheral neuronal signaling due to altered load transmission to a sensory receptor’s local mechanical environment are often considered a mechanism contributing to the therapeutic effects of spinal manipulation. The purpose of this study was to determine whether an HVLA-SM’s thrust amplitude or duration altered neural responsiveness of lumbar muscle spindles to either vertebral movement or position. METHODS Anesthetized cats (n=112) received L6 HVLA-SMs delivered to the spinous process. Cats were divided into 6 cohorts depending upon the peak thrust force (25%, 55%, 85% body weight) or thrust displacement (1, 2, 3mm) they received. Cats in each cohort received 8 thrust durations (0–250ms). Afferent discharge from 112 spindles was recorded in response to ramp and hold vertebral movement before and after the manipulation. Changes in mean instantaneous frequency (MIF) during the baseline period preceding the ramps (ΔMIFresting), during ramp movements (ΔMIFmovement), and with the vertebra held in the new position (ΔMIFposition) were compared. RESULTS Thrust duration had a small but statistically significant effect on ΔMIFresting at all six thrust amplitudes compared to control (0ms thrust duration). The lowest amplitude thrust displacement (1mm) increased ΔMIFresting at all thrust durations. For all the other thrust displacements and forces, the direction of change in ΔMIFresting was not consistent and the pattern of change was not systematically related to thrust duration. Regardless of thrust force, displacement, or duration, ΔMIFmovement and ΔMIFposition were not significantly different from control. Conclusion Relatively low amplitude thrust displacements applied during an HVLA-SM produced sustained increases in the resting discharge of paraspinal muscle spindles regardless of the duration over which the thrust was

Electrochemical characterization and control of triple-layer muscles

NASA Astrophysics Data System (ADS)

Otero, Toribio F.; Cortes, Maria T.

2000-06-01

The electrochemical characterization of triple-layers formed by a EPA (Electroactive Polymer)/double-sided tape/EPA, like artificial muscles is described. Those muscles were characterized working under constant potential or under constant current. Due to the electrochemical nature of the electrochemomechanical property, muscles working under constant current produce constant movements, consuming increasing energies at decreasing temperatures, decreasing concentrations of electrolytes or trailing increasing masses. Muscles working at constant potential response with a faster movement if the temperature or the concentration of the electrolyte increase, or if the trailed weight decreases. Specific charges and specific energies were determined for every experimental condition.

The muscle spindle as a feedback element in muscle control

NASA Technical Reports Server (NTRS)

Andrews, L. T.; Iannone, A. M.; Ewing, D. J.

1973-01-01

The muscle spindle, the feedback element in the myotatic (stretch) reflex, is a major contributor to muscular control. Therefore, an accurate description of behavior of the muscle spindle during active contraction of the muscle, as well as during passive stretch, is essential to the understanding of muscle control. Animal experiments were performed in order to obtain the data necessary to model the muscle spindle. Spectral density functions were used to identify a linear approximation of the two types of nerve endings from the spindle. A model reference adaptive control system was used on a hybrid computer to optimize the anatomically defined lumped parameter estimate of the spindle. The derived nonlinear model accurately predicts the behavior of the muscle spindle both during active discharge and during its silent period. This model is used to determine the mechanism employed to control muscle movement.

A simple method for assessment of muscle force, velocity, and power producing capacities from functional movement tasks.

PubMed

Zivkovic, Milena Z; Djuric, Sasa; Cuk, Ivan; Suzovic, Dejan; Jaric, Slobodan

2017-07-01

A range of force (F) and velocity (V) data obtained from functional movement tasks (e.g., running, jumping, throwing, lifting, cycling) performed under variety of external loads have typically revealed strong and approximately linear F-V relationships. The regression model parameters reveal the maximum F (F-intercept), V (V-intercept), and power (P) producing capacities of the tested muscles. The aim of the present study was to evaluate the level of agreement between the routinely used "multiple-load model" and a simple "two-load model" based on direct assessment of the F-V relationship from only 2 external loads applied. Twelve participants were tested on the maximum performance vertical jumps, cycling, bench press throws, and bench pull performed against a variety of different loads. All 4 tested tasks revealed both exceptionally strong relationships between the parameters of the 2 models (median R = 0.98) and a lack of meaningful differences between their magnitudes (fixed bias below 3.4%). Therefore, addition of another load to the standard tests of various functional tasks typically conducted under a single set of mechanical conditions could allow for the assessment of the muscle mechanical properties such as the muscle F, V, and P producing capacities.

Muscle Contraction.

PubMed

Sweeney, H Lee; Hammers, David W

2018-02-01

SUMMARYMuscle cells are designed to generate force and movement. There are three types of mammalian muscles-skeletal, cardiac, and smooth. Skeletal muscles are attached to bones and move them relative to each other. Cardiac muscle comprises the heart, which pumps blood through the vasculature. Skeletal and cardiac muscles are known as striated muscles, because the filaments of actin and myosin that power their contraction are organized into repeating arrays, called sarcomeres, that have a striated microscopic appearance. Smooth muscle does not contain sarcomeres but uses the contraction of filaments of actin and myosin to constrict blood vessels and move the contents of hollow organs in the body. Here, we review the principal molecular organization of the three types of muscle and their contractile regulation through signaling mechanisms and discuss their major structural and functional similarities that hint at the possible evolutionary relationships between the cell types. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Activity patterns of extrinsic finger flexors and extensors during movements of instructed and non-instructed fingers.

PubMed

van Beek, Nathalie; Stegeman, Dick F; van den Noort, Josien C; H E J Veeger, DirkJan; Maas, Huub

2018-02-01

The fingers of the human hand cannot be controlled fully independently. This phenomenon may have a neurological as well as a mechanical basis. Despite previous studies, the neuromechanics of finger movements are not fully understood. The aims of this study were (1) to assess the activation and coactivation patterns of finger specific flexor and extensor muscle regions during instructed single finger flexion and (2) to determine the relationship between enslaved finger movements and respective finger muscle activation. In 9 healthy subjects (age 22-29), muscle activation was assessed during single finger flexion using a 90 surface electromyography electrode grid placed over the flexor digitorum superficialis (FDS) and the extensor digitorum (ED). We found (1) no significant differences in muscle activation timing between fingers, (2) considerable muscle activity in flexor and extensor regions associated with the non-instructed fingers and (3) no correlation between the muscle activations and corresponding movement of non-instructed fingers. A clear disparity was found between the movement pattern of the non-instructed fingers and the activity pattern of the corresponding muscle regions. This suggests that mechanical factors, such as intertendinous and myofascial connections, may also affect finger movement independency and need to be taken into consideration when studying finger movement. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microgravity effects on 'postural' muscle activity patterns

NASA Technical Reports Server (NTRS)

Layne, Charles S.; Spooner, Brian S.

1994-01-01

Changes in neuromuscular activation patterns associated with movements made in microgravity can contribute to muscular atrophy. Using electromyography (EMG) to monitor 'postural' muscles, it was found that free floating arm flexions made in microgravity were not always preceded by neuromuscular activation patterns normally observed during movements made in unit gravity. Additionally, manipulation of foot sensory input during microgravity arm flexion impacted upon anticipatory postural muscle activation.

Muscle Repositioning: Combining Subjective and Objective Feedbacks in the Teaching and Practice of a Reflex-Based Myofascial Release Technique

PubMed Central

Bertolucci, Luiz Fernando

2010-01-01

Muscle Repositioning (MR) is a new style of myofascial release that elicits involuntary motor reactions detectable by electromyography. This article* describes the principal theoretical and practical concepts of MR, and summarizes a workshop presented October 31, 2009, after the Second International Fascia Research Congress, held at Vrije Universitiet, Amsterdam. The manual mechanical input of MR integrates the client’s body segments into a block, which is evident as a result of the diagnostic manual oscillations the practitioner imparts to the client’s body. Segmental integration is achieved when the client’s body responds as a unit to the oscillatory assessment. It appears that manually sustaining the condition of segmental integration evokes involuntary muscle reactions, which reactions might correspond to mechanisms that maintain homeostasis, such as pandiculation. It might be that these reactions are part of the MR mechanism of action and underlie its clinically observed efficacy in the treatment of musculoskeletal disorders. For the practitioner and the client alike, segmental integration provides unique sensations. In teaching MR, these paired sensations can be used as kinesthetic feedback resources, because quality of touch can be guided by the client’s reported sensations, which should match the practitioner’s sensations. Another form of feedback with respect to quality of touch is the visually discernable degree of segmental integration. Finally, because the involuntary motor activity elicited by the MR touch can be objectively monitored through electromyography and possibly other instrumented measurements, the MR approach might yield objectivity, precision, and reproducibility—features seldom found in manual therapies. PMID:21589699

Effective force control by muscle synergies

PubMed Central

Berger, Denise J.; d'Avella, Andrea

2014-01-01

Muscle synergies have been proposed as a way for the central nervous system (CNS) to simplify the generation of motor commands and they have been shown to explain a large fraction of the variation in the muscle patterns across a variety of conditions. However, whether human subjects are able to control forces and movements effectively with a small set of synergies has not been tested directly. Here we show that muscle synergies can be used to generate target forces in multiple directions with the same accuracy achieved using individual muscles. We recorded electromyographic (EMG) activity from 13 arm muscles and isometric hand forces during a force reaching task in a virtual environment. From these data we estimated the force associated to each muscle by linear regression and we identified muscle synergies by non-negative matrix factorization. We compared trajectories of a virtual mass displaced by the force estimated using the entire set of recorded EMGs to trajectories obtained using 4–5 muscle synergies. While trajectories were similar, when feedback was provided according to force estimated from recorded EMGs (EMG-control) on average trajectories generated with the synergies were less accurate. However, when feedback was provided according to recorded force (force-control) we did not find significant differences in initial angle error and endpoint error. We then tested whether synergies could be used as effectively as individual muscles to control cursor movement in the force reaching task by providing feedback according to force estimated from the projection of the recorded EMGs into synergy space (synergy-control). Human subjects were able to perform the task immediately after switching from force-control to EMG-control and synergy-control and we found no differences between initial movement direction errors and endpoint errors in all control modes. These results indicate that muscle synergies provide an effective strategy for motor coordination. PMID

Effective force control by muscle synergies.

PubMed

Berger, Denise J; d'Avella, Andrea

2014-01-01

Muscle synergies have been proposed as a way for the central nervous system (CNS) to simplify the generation of motor commands and they have been shown to explain a large fraction of the variation in the muscle patterns across a variety of conditions. However, whether human subjects are able to control forces and movements effectively with a small set of synergies has not been tested directly. Here we show that muscle synergies can be used to generate target forces in multiple directions with the same accuracy achieved using individual muscles. We recorded electromyographic (EMG) activity from 13 arm muscles and isometric hand forces during a force reaching task in a virtual environment. From these data we estimated the force associated to each muscle by linear regression and we identified muscle synergies by non-negative matrix factorization. We compared trajectories of a virtual mass displaced by the force estimated using the entire set of recorded EMGs to trajectories obtained using 4-5 muscle synergies. While trajectories were similar, when feedback was provided according to force estimated from recorded EMGs (EMG-control) on average trajectories generated with the synergies were less accurate. However, when feedback was provided according to recorded force (force-control) we did not find significant differences in initial angle error and endpoint error. We then tested whether synergies could be used as effectively as individual muscles to control cursor movement in the force reaching task by providing feedback according to force estimated from the projection of the recorded EMGs into synergy space (synergy-control). Human subjects were able to perform the task immediately after switching from force-control to EMG-control and synergy-control and we found no differences between initial movement direction errors and endpoint errors in all control modes. These results indicate that muscle synergies provide an effective strategy for motor coordination.

Approaches to involuntary admission of the mentally ill in the People’s Republic of China: Changes in legislation from 2002 to 2012

PubMed Central

Shao, Y; Xie, B

2015-01-01

Because a systematic analysis of laws on involuntary admission of the mentally ill in China does not exist, this paper explored the trajectory of the legislation on involuntary admission of the mentally ill in China; the social and cultural factors underlying these changes are also discussed. By describing and analyzing the differences or similarities of current legal frameworks and procedures for involuntary admission of the mentally ill across the seven local mental health regulations and the National Mental Health Act, one can see a trajectory of gradually more stringent legislation for involuntary admission during the past 10 years of China. The compromise, reversals, and circuitous paths during the legislation process reflect the difficulty the government faces in balancing the benefits between society and individuals, and explores the transformation of the mode of mental health services. The approach in the 2012 National Mental Health Act, despite some weaknesses, is an important step to standardize the diverse practices in involuntary admission of the mentally ill in China. Further research on the influence of the National Act on mental health services is clearly needed. PMID:25770277

Mandibular movement during sleep bruxism associated with current tooth attrition.

PubMed

Okura, Kazuo; Shigemoto, Shuji; Suzuki, Yoshitaka; Noguchi, Naoto; Omoto, Katsuhiro; Abe, Susumu; Matsuka, Yoshizo

2017-01-01

Observation of attrition patterns suggests that mandibular movement in sleep bruxism (SB) may be associated with current tooth attrition. The aim of this study was to confirm this phenomenon by investigating mandibular movement and masseter muscle activity. The subject was a healthy 21-year-old Japanese male. We recorded biological signals including mandibular movement and masseter electromyograms (EMGs) with a polysomnograph. Based on the EMG using Okura's criteria, SB events were classified into clenching, grinding and mixed types according to mandibular movement criteria. The close-open mandibular movement cycles (CO-cycles) during grinding and mixed type events were selected based on mandibular movement trajectories. Fifty-eight CO-cycles were selected in seven grinding and three mixed types. We found that SB mandibular movements associated with current tooth attrition. Excessive lateral movements (ELM) beyond the canine edge-to-edge position were observed in the closing (10.3%) and opening (13.8%) phases of the CO-cycle. Total masseter muscle activity was significantly higher during voluntary grinding (VGR) than during CO-cycle including ELM (working side: P=0.036, balancing side: P=0.025). However, in the middle and late parts of the opening phase, working side masseter muscle activity was significantly higher during CO-cycle including ELM than during VGR (P=0.012). In the early part of the closing phase, balancing side masseter muscle activity was significantly higher during CO-cycle including ELM than during VGR (P=0.017). These findings suggest that excessive forceful grinding during ongoing SB events may have caused canine attrition in this patient. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Strategic Involuntary Teacher Transfers and Teacher Performance: Examining Equity and Efficiency

ERIC Educational Resources Information Center

Grissom, Jason A.; Loeb, Susanna; Nakashima, Nathaniel A.

2014-01-01

Despite claims that school districts need flexibility in teacher assignment to allocate teachers more equitably across schools and improve district performance, the power to involuntarily transfer teachers across schools remains hotly contested. Little research has examined involuntary teacher transfer policies or their effects on schools,…

Classics in psychiatry and the law: Francis Wharton on involuntary confessions.

PubMed

Weiss, Kenneth J

2012-01-01

Philadelphia attorney Francis Wharton was a key intellectual figure in linking the sciences of medicine and law. In 1860, he published a monograph on involuntary confessions, which represented the closing chapter of Wharton and Stillé's Treatise on Medical Jurisprudence. He had already published A Monograph on Mental Unsoundness in 1855, the first book of the Treatise in its first edition. Wharton was convinced that many criminals had an inner compulsion to confess or to be caught, explained as divine jurisprudence. His remarks on confessions include a typology spanning psychodynamics to police tactics, using contemporaneous, historical, and literary examples. This remarkable document provides insight into the dynamics of unintended and involuntary confessions and is compatible, in part, with current scholarship. The author contrasts Wharton's schema with those of his English predecessor Jeremy Bentham, the psychoanalyst Theodore Reik, and others, and concludes that it represents an important transition toward a psychological approach to the criminology of confessions.

Multipulse control of saccadic eye movements

NASA Technical Reports Server (NTRS)

Lehman, S. L.; Stark, L.

1981-01-01

We present three conclusions regarding the neural control of saccadic eye movements, resulting from comparisons between recorded movements and computer simulations. The controller signal to the muscles is probably a multipulse-step. This kind of signal drives the fastest model trajectories. Finally, multipulse signals explain differences between model and electrophysiological results.

Using Hypnotic Suggestion to Model Loss of Control and Awareness of Movements: An Exploratory fMRI Study

PubMed Central

Oakley, David A.; Bell, Vaughan; Koppel, Cristina; Mehta, Mitul A.; Halligan, Peter W.

2013-01-01

The feeling of voluntary control and awareness of movement is fundamental to our notions of selfhood and responsibility for actions, yet can be lost in neuropsychiatric syndromes (e.g. delusions of control, non-epileptic seizures) and culturally influenced dissociative states (e.g. attributions of spirit possession). The brain processes involved remain poorly understood. We used suggestion and functional magnetic resonance imaging (fMRI) to investigate loss of control and awareness of right hand movements in 15 highly hypnotically suggestible subjects. Loss of perceived control of movements was associated with reduced connectivity between supplementary motor area (SMA) and motor regions. Reduced awareness of involuntary movements was associated with less activation in parietal cortices (BA 7, BA 40) and insula. Collectively these results suggest that the sense of voluntary control of movement may critically depend on the functional coupling of SMA with motor systems, and provide a potential neural basis for the narrowing of awareness reported in pathological and culturally influenced dissociative phenomena. PMID:24205198

A thixotropic effect in contracting rabbit psoas muscle: prior movement reduces the initial tension response to stretch

PubMed Central

Campbell, Kenneth S; Moss, Richard L

2000-01-01

Paired ramp stretches and releases (‘triangular length changes’, typically 0.04 ± 0.09L0 s−1; mean ±s.e.m.) were imposed on permeabilised rabbit psoas fibre segments under sarcomere length control. In actively contracting fibres, the tension response to stretch was biphasic; tension rose more rapidly during the first 0.005L0 of the imposed stretch than thereafter. Tension also dropped in a biphasic manner during shortening, and at the end of the length change was reduced below the steady state. If a second triangular length change was imposed shortly after the first, tension rose less sharply during the initial phase of lengthening, i.e. the stiffness of the muscle during the initial phase of the response was reduced in the second stretch. This is a thixotropic effect. If a third triangular length change was imposed on the muscle, the response was the same as that to the second. The time required to recover the original tension response was measured by varying the interval between triangular length changes. Recovery to steady state occurred at a rate of ∼1 s−1. The stiffness of the muscle during the initial phase of the response scaled with the developed tension in pCa (=−log10[Ca2+]) solutions ranging from 6.3 (minimal activation) to 4.5 (saturating effect). The relative thixotropic reduction in stiffness measured using paired length changes was independent of the pCa of the activating solution. The thixotropic behaviour of contracting skeletal muscle can be explained by a cross-bridge model of muscle contraction in which the number of attached cross-bridges is temporarily reduced following an imposed movement. PMID:10835052

Mind-muscle connection training principle: influence of muscle strength and training experience during a pushing movement.

PubMed

Calatayud, Joaquin; Vinstrup, Jonas; Jakobsen, Markus D; Sundstrup, Emil; Colado, Juan Carlos; Andersen, Lars L

2017-07-01

To investigate the effect of different attentional focus conditions on muscle activity during the push-up exercise and to assess the possible influence of muscle strength and training experience. Eighteen resistance-trained men performed 1RM bench press testing and were familiarized with the procedure during the first session. In the second session, three different conditions were randomly performed: regular push-up and push-up focusing on using the pectoralis major and triceps brachii muscles, respectively. Surface electromyography (EMG) was recorded and analyzed (EMG normalized to max; nEMG) for the triceps brachii and pectoralis major muscles. Participants had on average 8 (SD 6) years of training experience and 1RM of 1.25 (SD 0.28) kg per kg bodyweight. Focusing on using pectoralis major increased activity in this muscle by 9% nEMG (95% CI 5-13; Cohen's d 0.60) compared with the regular condition. Triceps activity was not significantly influenced by triceps focus although borderline significant, with a mean difference of 5% nEMG (95% CI 0-10; Cohen's d 0.30). However, years of training experience was positively associated with the ability to selectively activate the triceps (β = 0.41, P = 0.04), but not the pectoralis. Bench press 1RM was not significantly associated with the ability to selectively activate the muscles. Pectoralis activity can be increased when focusing on using this muscle during push-ups, whereas the ability to do this for the triceps is dependent on years of training experience. Maximal muscle strength does not appear to be a decisive factor for the ability to selectively activate these muscles.

The effect of movement and load on the dynamic coupling of abdominal electromyography.

PubMed

King, Adam C

2018-05-14

This study investigated the degree of neural coupling in abdominal muscle activity and whether the task constraints of movement and load altered the coupling within three muscle pairings. Nineteen young, physically-active individuals performed sit-up and reverse crunch movements in bodyweight (BW) and loaded (+4.54 kg) conditions. Surface electromyography (sEMG) was recorded from the rectus abdominus (RA), external oblique (EO), and transverse abdominus (TA) muscles. Linear (correlation coefficient) and non-linear (Cross-Approximate Entropy) measurements evaluated the degree of couplings across three muscle pairings. Compared to a resting coupling state, most conditions showed evidence of coupling. The linear coupling showed greater coupling compared to the resting state. Dynamic coupling showed lower degrees of coupling for the RA-EO and RA-TA pairings but stronger coupling for the EO-TA pairing with the sit-up movement exhibiting lower Cross-ApEn (higher dynamic coupling) than the reverse crunch. The results provide preliminary evidence of coupling in abdominal muscle activity that was influenced by movement, but not load. The functional roles of the RA (prime mover), EO and TA (stabilizers) muscles may have influenced the degree of coupling and future investigations are needed to better understand the coupling of abdominal muscle activity. Copyright © 2018 Elsevier B.V. All rights reserved.

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.

Cervical intraspinal microstimulation evokes robust forelimb movements before and after injury

NASA Astrophysics Data System (ADS)

Sunshine, Michael D.; Cho, Frances S.; Lockwood, Danielle R.; Fechko, Amber S.; Kasten, Michael R.; Moritz, Chet T.

2013-06-01

Objective. Intraspinal microstimulation (ISMS) is a promising method for reanimating paralyzed limbs following neurological injury. ISMS within the cervical and lumbar spinal cord is capable of evoking a variety of highly-functional movements prior to injury, but the ability of ISMS to evoke forelimb movements after cervical spinal cord injury is unknown. Here we examine the forelimb movements and muscles activated by cervical ISMS both before and after contusion injury. Approach. We documented the forelimb muscles activated and movements evoked via systematic stimulation of the rodent cervical spinal cord both before injury and three, six and nine weeks following a moderate C4/C5 lateralized contusion injury. Animals were anesthetized with isoflurane to permit construction of somatotopic maps of evoked movements and quantify evoked muscle synergies between cervical segments C3 and T1. Main results. When ISMS was delivered to the cervical spinal cord, a variety of responses were observed at 68% of locations tested, with a spatial distribution that generally corresponded to the location of motor neuron pools. Stimulus currents required to achieve movement and the number of sites where movements could be evoked were unchanged by spinal cord injury. A transient shift toward extension-dominated movements and restricted muscle synergies were observed at three and six weeks following injury, respectively. By nine weeks after injury, however, ISMS-evoked patterns were similar to spinally-intact animals. Significance. The results demonstrate the potential for cervical ISMS to reanimate hand and arm function following spinal cord injury. Robust forelimb movements can be evoked both before and during the chronic stages of recovery from a clinically relevant and sustained cervical contusion injury.

Mirror movements in unilateral spastic cerebral palsy: Specific negative impact on bimanual activities of daily living.

PubMed

Adler, Caroline; Berweck, Steffen; Lidzba, Karen; Becher, Thomas; Staudt, Martin

2015-09-01

Mirror movements are involuntary movements of the other hand during voluntary unimanual movements. Some, but not all children with unilateral spastic cerebral palsy (USCP) show this phenomenon. In this observational study, we investigated whether these mirror movements have a specific negative impact on bimanual activities of daily living. Eighteen children (six girls; age range, 6-16 years; mean age, 12 years 1 month; SD, 3 years 3 month) with USCP, nine with and nine without mirror movements, underwent the Jebsen Taylor Hand Function Test (unimanual capacity) and the Assisting Hand Assessment (bimanual performance). In addition, we measured the time the participants needed for the completion of five activities we had identified as particularly difficult for children with mirror movements. Multivariate analysis demonstrated that mirror movements indeed have a specific negative impact on bimanual performance (Assisting Hand Assessment) and on the time needed for the completion of these five particularly difficult activities. This effect was independent from unimanual capacity. Functional therapies in children with USCP and mirror movements should address this phenomenon. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Involuntary psychiatric holds - the structure of admissions on the example of Institute of Psychiatry and Neurology in Warsaw.

PubMed

Markiewicz, Inga; Heitzman, Janusz; Gardyńska-Ziemba, Ewa

2016-01-01

The aim of the study was to analyse the structure of involuntary psychiatric holds in Institute of Psychiatry and Neurology in Warsaw, throughout the year. Our research interests included socio-demographic profiles of the patients, time of admissions (time of a day/night/ season), type of diagnoses at admission and suicide attempts preceding the admission. We also analysed the normative aspect of involuntary admissions, i.e. which Articles of the Polish Mental Health Act constituted the basis for these patients admission, and if the choice of articles was justifiable by a diagnosis of the mental disorder. The primary research tool consisted of an original questionnaire allowing for the collection of relevant data. The material was submitted to statistical analysis, using primarily simple percentage methods. Involuntary psychiatric holds constituted 15.8% of the total number of admissions to the Institute of Psychiatry and Neurology (3,498 persons) in 2012. 522 persons with mental disorders were subject to involuntary admission on emergency basis (292 women and 260 men). Majority of patients was over 40 years old. The number of patients admitted to the Institute of Psychiatry and Neurology on emergency basis without the consent ranged from 38 to 62 people per month. Season did not differentiate significantly the number of admitted persons, majority of patients was admitted during the day (82%). Among the diagnosed patients, paranoid schizophrenia was the most frequent illness (43%), delirium tremens (7%), bipolar disorders (6%), dementia (5%), other psychotic disorders (5%), paranoid syndrome (5%), schizoaffective disorder (5%), other diagnoses (less than 1%). 4% of admissions to the Institute of Psychiatry and Neurology were due to attempted suicide. 37% of patients were admitted to the Institute of Psychiatry and Neurology under Article 23.1 of the Mental Health Act, 34% under Article 22.2, in accordance with Article 24.1 - only 7% of patients. Invoking Article 28

Muscle Co-activation: Definitions, Mechanisms, and Functions.

PubMed

Latash, Mark L

2018-03-28

The phenomenon of agonist-antagonist muscle co-activation is discussed with respect to its consequences for movement mechanics (such as increasing joint apparent stiffness, facilitating faster movements, and effects on action stability), implication for movement optimization, and involvement of different neurophysiological structures. Effects of co-activation on movement stability are ambiguous and depend on the effector representing a kinematic chain with a fixed origin or free origin. Further, co-activation is discussed within the framework of the equilibrium-point hypothesis and the idea of hierarchical control with spatial referent coordinates. Relations of muscle co-activation to changes in one of the basic commands, the c-command, are discussed and illustrated. A hypothesis is suggested that agonist-antagonist co-activation reflects a deliberate neural control strategy to preserve effector-level control and avoid making it degenerate and facing the necessity to control at the level of signals to individual muscles. This strategy, in particular, allows stabilizing motor actions by co-varied adjustments in spaces of control variables. This hypothesis is able to account for higher levels of co-activation in young healthy persons performing challenging tasks and across various populations with movement impairments.

The decreased responsiveness of lumbar muscle spindles to a prior history of spinal muscle lengthening is graded with the magnitude of change in vertebral position

PubMed Central

Ge, Weiqing; Pickar, Joel G.

2013-01-01

In the lumbar spine, muscle spindle responsiveness is affected by the duration and direction of a lumbar vertebra’s positional history. The purpose of the present study was to determine the relationship between changes in the magnitude of a lumbar vertebra’s positional history and the responsiveness of lumbar muscle spindles to a subsequent vertebral position and subsequent vertebral movement. Neural activity from multifidus and longissimus muscle spindle afferents in deeply anesthetized cats was recorded while creating positional histories of the L6 vertebra. History was induced using a displacement-controlled feedback motor. It held the L6 vertebra for 4 seconds at an intermediate position (hold-intermediate at 0mm) and at 7 positions from 0.07 to 1.55mm more ventralward and dorsalward which lengthened (hold-long) and shortened (hold-short) the lumbar muscles. Following the conditioning hold positions, L6 was returned to the intermediate position. Muscle spindle discharge at this position and during a lengthening movement was compared between hold-intermediate and hold-short conditionings and between hold-intermediate and hold-short conditionings. We found that regardless of conditioning magnitude, the 7 shortening magnitudes similarly increased muscle spindle responsiveness to both vertebral position and movement. In contrast, the 7 lengthening magnitudes produced a graded decrease in responsiveness to both position and movement. The decrease to position became maximal following conditioning magnitudes of ~0.75 mm. The decrease to movement did not reach a maximum even with conditioning magnitudes of ~1.55 mm. The data suggest that the fidelity of proprioceptive information from muscle spindles in the low back is influenced by small changes in the previous length history of lumbar muscles. PMID:22721784

Physiological modules for generating discrete and rhythmic movements: component analysis of EMG signals.

PubMed

Bengoetxea, Ana; Leurs, Françoise; Hoellinger, Thomas; Cebolla, Ana Maria; Dan, Bernard; Cheron, Guy; McIntyre, Joseph

2014-01-01

A central question in Neuroscience is that of how the nervous system generates the spatiotemporal commands needed to realize complex gestures, such as handwriting. A key postulate is that the central nervous system (CNS) builds up complex movements from a set of simpler motor primitives or control modules. In this study we examined the control modules underlying the generation of muscle activations when performing different types of movement: discrete, point-to-point movements in eight different directions and continuous figure-eight movements in both the normal, upright orientation and rotated 90°. To test for the effects of biomechanical constraints, movements were performed in the frontal-parallel or sagittal planes, corresponding to two different nominal flexion/abduction postures of the shoulder. In all cases we measured limb kinematics and surface electromyographic activity (EMG) signals for seven different muscles acting around the shoulder. We first performed principal component analysis (PCA) of the EMG signals on a movement-by-movement basis. We found a surprisingly consistent pattern of muscle groupings across movement types and movement planes, although we could detect systematic differences between the PCs derived from movements performed in each shoulder posture and between the principal components associated with the different orientations of the figure. Unexpectedly we found no systematic differences between the figure eights and the point-to-point movements. The first three principal components could be associated with a general co-contraction of all seven muscles plus two patterns of reciprocal activation. From these results, we surmise that both "discrete-rhythmic movements" such as the figure eight, and discrete point-to-point movement may be constructed from three different fundamental modules, one regulating the impedance of the limb over the time span of the movement and two others operating to generate movement, one aligned with the

Changes in muscle coordination with training.

PubMed

Carson, Richard G

2006-11-01

Three core concepts, activity-dependent coupling, the composition of muscle synergies, and Hebbian adaptation, are discussed with a view to illustrating the nature of the constraints imposed by the organization of the central nervous system on the changes in muscle coordination induced by training. It is argued that training invoked variations in the efficiency with which motor actions can be generated influence the stability of coordination by altering the potential for activity-dependent coupling between the cortical representations of the focal muscles recruited in a movement task and brain circuits that do not contribute directly to the required behavior. The behaviors that can be generated during training are also constrained by the composition of existing intrinsic muscle synergies. In circumstances in which attempts to produce forceful or high velocity movements would otherwise result in the generation of inappropriate actions, training designed to promote the development of control strategies specific to the desired movement outcome may be necessary to compensate for protogenic muscle recruitment patterns. Hebbian adaptation refers to processes whereby, for neurons that release action potentials at the same time, there is an increased probability that synaptic connections will be formed. Neural connectivity induced by the repetition of specific muscle recruitment patterns during training may, however, inhibit the subsequent acquisition of new skills. Consideration is given to the possibility that, in the presence of the appropriate sensory guidance, it is possible to gate Hebbian plasticity and to promote greater subsequent flexibility in the recruitment of the trained muscles in other task contexts.

Dynamic modulation of corticospinal excitability and short-latency afferent inhibition during onset and maintenance phase of selective finger movement.

PubMed

Cho, Hyun Joo; Panyakaew, Pattamon; Thirugnanasambandam, Nivethida; Wu, Tianxia; Hallett, Mark

2016-06-01

During highly selective finger movement, corticospinal excitability is reduced in surrounding muscles at the onset of movement but this phenomenon has not been demonstrated during maintenance of movement. Sensorimotor integration may play an important role in selective movement. We sought to investigate how corticospinal excitability and short-latency afferent inhibition changes in active and surrounding muscles during onset and maintenance of selective finger movement. Using transcranial magnetic stimulation (TMS) and paired peripheral stimulation, input-output recruitment curve and short-latency afferent inhibition (SAI) were measured in the first dorsal interosseus and abductor digiti minimi muscles during selective index finger flexion. Motor surround inhibition was present only at the onset phase, but not at the maintenance phase of movement. SAI was reduced at onset but not at the maintenance phase of movement in both active and surrounding muscles. Our study showed dynamic changes in corticospinal excitability and sensorimotor modulation for active and surrounding muscles in different movement states. SAI does not appear to contribute to motor surround inhibition at the movement onset phase. Also, there seems to be different inhibitory circuit(s) other than SAI for the movement maintenance phase in order to delineate the motor output selectively when corticospinal excitability is increased in both active and surrounding muscles. This study enhances our knowledge of dynamic changes in corticospinal excitability and sensorimotor interaction in different movement states to understand normal and disordered movements. Published by Elsevier Ireland Ltd.

The Moving Rubber Hand Illusion Reveals that Explicit Sense of Agency for Tapping Movements Is Preserved in Functional Movement Disorders.

PubMed

Marotta, Angela; Bombieri, Federica; Zampini, Massimiliano; Schena, Federico; Dallocchio, Carlo; Fiorio, Mirta; Tinazzi, Michele

2017-01-01

Functional movement disorders (FMD) are characterized by motor symptoms (e.g., tremor, gait disorder, and dystonia) that are not compatible with movement abnormalities related to a known organic cause. One key clinical feature of FMD is that motor symptoms are similar to voluntary movements but are subjectively experienced as involuntary by patients. This gap might be related to abnormal self-recognition of bodily action, which involves two main components: sense of agency and sense of body ownership. The aim of this study was to systematically investigate whether this function is altered in FMD, specifically focusing on the subjective feeling of agency, body ownership, and their interaction during normal voluntary movements. Patients with FMD ( n = 21) and healthy controls ( n = 21) underwent the moving Rubber Hand Illusion (mRHI), in which passive and active movements can differentially elicit agency, ownership or both. Explicit measures of agency and ownership were obtained via a questionnaire. Patients and controls showed a similar pattern of response: when the rubber hand was in a plausible posture, active movements elicited strong agency and ownership; implausible posture of the rubber hand abolished ownership but not agency; passive movements suppressed agency but not ownership. These findings suggest that explicit sense of agency and body ownership are preserved in FMD. The latter finding is shared by a previous study in FMD using a static version of the RHI, whereas the former appears to contrast with studies demonstrating altered implicit measures of agency (e.g., sensory attenuation). Our study extends previous findings by suggesting that in FMD: (i) the sense of body ownership is retained also when interacting with the motor system; (ii) the subjective experience of agency for voluntary tapping movements, as measured by means of mRHI, is preserved.

The Moving Rubber Hand Illusion Reveals that Explicit Sense of Agency for Tapping Movements Is Preserved in Functional Movement Disorders

PubMed Central

Marotta, Angela; Bombieri, Federica; Zampini, Massimiliano; Schena, Federico; Dallocchio, Carlo; Fiorio, Mirta; Tinazzi, Michele

2017-01-01

Functional movement disorders (FMD) are characterized by motor symptoms (e.g., tremor, gait disorder, and dystonia) that are not compatible with movement abnormalities related to a known organic cause. One key clinical feature of FMD is that motor symptoms are similar to voluntary movements but are subjectively experienced as involuntary by patients. This gap might be related to abnormal self-recognition of bodily action, which involves two main components: sense of agency and sense of body ownership. The aim of this study was to systematically investigate whether this function is altered in FMD, specifically focusing on the subjective feeling of agency, body ownership, and their interaction during normal voluntary movements. Patients with FMD (n = 21) and healthy controls (n = 21) underwent the moving Rubber Hand Illusion (mRHI), in which passive and active movements can differentially elicit agency, ownership or both. Explicit measures of agency and ownership were obtained via a questionnaire. Patients and controls showed a similar pattern of response: when the rubber hand was in a plausible posture, active movements elicited strong agency and ownership; implausible posture of the rubber hand abolished ownership but not agency; passive movements suppressed agency but not ownership. These findings suggest that explicit sense of agency and body ownership are preserved in FMD. The latter finding is shared by a previous study in FMD using a static version of the RHI, whereas the former appears to contrast with studies demonstrating altered implicit measures of agency (e.g., sensory attenuation). Our study extends previous findings by suggesting that in FMD: (i) the sense of body ownership is retained also when interacting with the motor system; (ii) the subjective experience of agency for voluntary tapping movements, as measured by means of mRHI, is preserved. PMID:28634447

Feed-forward motor control of ultrafast, ballistic movements.

PubMed

Kagaya, K; Patek, S N

2016-02-01

To circumvent the limits of muscle, ultrafast movements achieve high power through the use of springs and latches. The time scale of these movements is too short for control through typical neuromuscular mechanisms, thus ultrafast movements are either invariant or controlled prior to movement. We tested whether mantis shrimp (Stomatopoda: Neogonodactylus bredini) vary their ultrafast smashing strikes and, if so, how this control is achieved prior to movement. We collected high-speed images of strike mechanics and electromyograms of the extensor and flexor muscles that control spring compression and latch release. During spring compression, lateral extensor and flexor units were co-activated. The strike initiated several milliseconds after the flexor units ceased, suggesting that flexor activity prevents spring release and determines the timing of strike initiation. We used linear mixed models and Akaike's information criterion to serially evaluate multiple hypotheses for control mechanisms. We found that variation in spring compression and strike angular velocity were statistically explained by spike activity of the extensor muscle. The results show that mantis shrimp can generate kinematically variable strikes and that their kinematics can be changed through adjustments to motor activity prior to the movement, thus supporting an upstream, central-nervous-system-based control of ultrafast movement. Based on these and other findings, we present a shishiodoshi model that illustrates alternative models of control in biological ballistic systems. The discovery of feed-forward control in mantis shrimp sets the stage for the assessment of targets, strategic variation in kinematics and the role of learning in ultrafast animals. © 2016. Published by The Company of Biologists Ltd.

Sociodemographic and medical characteristics of involuntary psychiatric inpatients--retrospective study of five-year experience with Croatian Act on Mental Health.

PubMed

Potkonjak, Jelena; Karlović, Dalibor

2008-09-01

The aim of this study was to analyze sociodemographic and medical characteristics of involuntary psychiatric inpatients treated during the five-year period of implementation of the Croatian Act on Mental Health. Data on involuntarily hospitalized patients according to the Croatian Act on Mental Health were singled out from the pool of inpatients treated at University Department of Psychiatry, Sestre milosrdnice University Hospital from January 1, 1998 till December 31, 2002. Data were collected from medical records. Patients were diagnosed according to the International Classification of Diseases, 10th revision criteria. The prevalence of involuntary hospitalization was 2%, including a comparative number of male and female patients. Most patients had secondary school, were living alone, were unmarried, widowed or divorced, and did not work at the time of hospitalization; however, most patients had some kind of health insurance. Schizophrenia was the most common diagnosis in involuntary psychiatric inpatients. In conclusion, scientific evaluation of involuntary hospitalization poses a major problem because of the many different factors that can influence the prevalence of involuntary hospitalization. Some of this factors are type of institution (psychiatric hospital or psychiatry department at a general hospital), organization of psychiatric care in the region, psychiatric morbidity and dynamics of changes in psychiatric morbidity in a specific region, public opinion about people with mental disorders, legal provisions on this very sensitive topic, etc.

Control of movement distance in Parkinson's disease.

PubMed

Pfann, K D; Buchman, A S; Comella, C L; Corcos, D M

2001-11-01

Studies of electromyographic (EMG) patterns during movements in Parkinson's disease (PD) have often yielded contradictory results, making it impossible to derive a set of rules to explain how muscles are activated to perform different movement tasks. We sought to clarify the changes in modulation of EMG parameters associated with control of movement distance during fast movements in patients with PD. Specifically, we studied surface EMG activity during rapid elbow flexion movements over a wide range of distances (5-72 degrees) in 14 patients with relatively mild symptoms of PD and 14 control subjects of similar age, sex, height, and weight. The PD group exhibited several changes in EMG modulation including impaired modulation of agonist burst duration; increased number of agonist bursts; reduced scaling of agonist EMG magnitude in the more severely impaired subjects; and increased temporal overlap of the antagonist and agonist signals in the most severely impaired subjects. These findings suggest that progressive motor dysfunction in PD is accompanied by increasing deficits in modulating muscle activation. These results help clarify previous disparate and sometimes contradictory results of EMG patterns in subjects with PD. Copyright 2001 Movement Disorder Society.

Velopharyngeal closure and the longus capitis muscle.

PubMed

Yamawaki, Y; Nishimura, Y; Suzuki, Y

1996-09-01

The dynamic mechanism of velopharyngeal function not only in normal individuals but also in patients with velopharyngeal insufficiency, which is mainly related to cleft palate, has been the subject of considerable interest and controversy. Recently, in order to clarify velopharyngeal movement in the valvular action on phonation we examined dynamic MR images of this area taken in the transverse plane in parallel with the muscle sling of levator veli palatini. In cases in whom the closure pattern in that plane is circular, detailed observation revealed a very interesting result; that is, the longus capitis muscle, one of the group of anterior vertebral muscles, is directly involved in velopharyngeal valving function. It has not previously been reported that the longus capitis muscle acts as one of the velopharyngeal closure muscles, in addition to levator veli palatini. The present study demonstrated that contraction of the muscle contributed to velopharyngeal closure by forward movement of the pharyngeal wall.

An ocular biomechanic model for dynamic simulation of different eye movements.

PubMed

Iskander, J; Hossny, M; Nahavandi, S; Del Porto, L

2018-04-11

Simulating and analysing eye movement is useful for assessing visual system contribution to discomfort with respect to body movements, especially in virtual environments where simulation sickness might occur. It can also be used in the design of eye prosthesis or humanoid robot eye. In this paper, we present two biomechanic ocular models that are easily integrated into the available musculoskeletal models. The model was previously used to simulate eye-head coordination. The models are used to simulate and analyse eye movements. The proposed models are based on physiological and kinematic properties of the human eye. They incorporate an eye-globe, orbital suspension tissues and six muscles with their connective tissues (pulleys). Pulleys were incorporated in rectus and inferior oblique muscles. The two proposed models are the passive pulleys and the active pulleys models. Dynamic simulations of different eye movements, including fixation, saccade and smooth pursuit, are performed to validate both models. The resultant force-length curves of the models were similar to the experimental data. The simulation results show that the proposed models are suitable to generate eye movement simulations with results comparable to other musculoskeletal models. The maximum kinematic root mean square error (RMSE) is 5.68° and 4.35° for the passive and active pulley models, respectively. The analysis of the muscle forces showed realistic muscle activation with increased muscle synergy in the active pulley model. Copyright © 2018 Elsevier Ltd. All rights reserved.

Kinematic parameters of hand movement during a disparate bimanual movement task in children with unilateral Cerebral Palsy.

PubMed

Rudisch, Julian; Butler, Jenny; Izadi, Hooshang; Zielinski, Ingar Marie; Aarts, Pauline; Birtles, Deirdre; Green, Dido

2016-04-01

Children with unilateral Cerebral Palsy (uCP) experience problems performing tasks requiring the coordinated use of both hands (bimanual coordination; BC). Additionally, some children with uCP display involuntary symmetrical activation of the opposing hand (mirrored movements). Measures, used to investigate therapy-related improvements focus on the functionality of the affected hand during unimanual or bimanual tasks. None however specifically address spatiotemporal integration of both hands. We explored the kinematics of hand movements during a bimanual task to identify parameters of BC. Thirty-seven children (aged 10.9±2.6years, 20 male) diagnosed with uCP participated. 3D kinematic motion analysis was performed during the task requiring opening of a box with their affected- (AH) or less-affected hand (LAH), and pressing a button inside with the opposite hand. Temporal and spatial components of data were extracted and related to measures of hand function and level of impairment. Total task duration was correlated with the Jebsen-Taylor Test of Hand Function in both conditions (either hand leading with the lid-opening). Spatial accuracy of the LAH when the box was opened with their AH was correlated with outcomes on the Children's Hand Use Experience Questionnaire. Additionally, we found a subgroup of children displaying non-symmetrical movement interference associated with greater movement overlap when their affected hand opened the box. This subgroup also demonstrated decreased use of the affected hand during bimanual tasks. Further investigation of bimanual interference, which goes beyond small scaled symmetrical mirrored movements, is needed to consider its impact on bimanual task performance following early unilateral brain injury. Copyright © 2016 Elsevier B.V. All rights reserved.

Involuntary Departure of Public School Principals in the State of Texas

ERIC Educational Resources Information Center

Davila, Elva Jimenez

2010-01-01

Few studies have examined the reasons for ineffective public school leadership. The study examined the factors associated with the involuntary departure of public school principals in the state of Texas and aimed to reveal the ineffective behaviors that erode the public school principal's leadership. The study also indirectly pointed out to…

Physiological modules for generating discrete and rhythmic movements: component analysis of EMG signals

PubMed Central

Bengoetxea, Ana; Leurs, Françoise; Hoellinger, Thomas; Cebolla, Ana Maria; Dan, Bernard; Cheron, Guy; McIntyre, Joseph

2015-01-01

A central question in Neuroscience is that of how the nervous system generates the spatiotemporal commands needed to realize complex gestures, such as handwriting. A key postulate is that the central nervous system (CNS) builds up complex movements from a set of simpler motor primitives or control modules. In this study we examined the control modules underlying the generation of muscle activations when performing different types of movement: discrete, point-to-point movements in eight different directions and continuous figure-eight movements in both the normal, upright orientation and rotated 90°. To test for the effects of biomechanical constraints, movements were performed in the frontal-parallel or sagittal planes, corresponding to two different nominal flexion/abduction postures of the shoulder. In all cases we measured limb kinematics and surface electromyographic activity (EMG) signals for seven different muscles acting around the shoulder. We first performed principal component analysis (PCA) of the EMG signals on a movement-by-movement basis. We found a surprisingly consistent pattern of muscle groupings across movement types and movement planes, although we could detect systematic differences between the PCs derived from movements performed in each shoulder posture and between the principal components associated with the different orientations of the figure. Unexpectedly we found no systematic differences between the figure eights and the point-to-point movements. The first three principal components could be associated with a general co-contraction of all seven muscles plus two patterns of reciprocal activation. From these results, we surmise that both “discrete-rhythmic movements” such as the figure eight, and discrete point-to-point movement may be constructed from three different fundamental modules, one regulating the impedance of the limb over the time span of the movement and two others operating to generate movement, one aligned with the

Commercial sex behaviours among involuntary male bachelors: findings from a survey of migrants in Xi'an, China.

PubMed

Yang, Xueyan; Li, Shuzhuo; Attané, Isabelle; Feldman, Marcus W

2015-06-01

The highly male-biased sex ratio at birth has produced a severe male 'marriage squeeze' in China. However, with an imbalanced sex ratio, the marriage-squeezed or involuntary bachelors can meet their sexual needs only through ways other than marriage. To investigate the commercial sex behaviours of involuntary bachelors, we conducted a survey on reproductive health and family living among male migrant bachelors in Xi'an City, the capital of Shaanxi Province, from December 2009 to January 2010. The prevalence of commercial sex use was 37.2% among unmarried men, 30.1% among married but separated men and 17.2% among married and cohabitating men (χ(2) = 31.33; P = 0.000; df = 2). Marital status, knowledge about acquired immunodeficiency syndrome (AIDS), age and income were associated with the prevalence and frequency of commercial sex behaviours. Condom use was less frequent among involuntary bachelors and was significantly associated with knowledge about AIDS and other sexually transmitted diseases, the frequency of commercial sex behaviours, marital status and age. The higher prevalence of commercial sex behaviours and the lower frequency of condom use indicate a higher risk of disease from commercial sex among involuntary bachelors, implicating both individual and public health. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The Influence of Plantar Short Foot Muscle Exercises on Foot Posture and Fundamental Movement Patterns in Long-Distance Runners, a Non-Randomized, Non-Blinded Clinical Trial.

PubMed

Sulowska, Iwona; Oleksy, Łukasz; Mika, Anna; Bylina, Dorota; Sołtan, Jarosław

2016-01-01

The objective of this study was to evaluate the influence of two kinds of plantar short foot muscles exercise on foot posture and fundamental movement patterns in long-distance runners. A parallel group non-blinded trial with 6-week follow-up. Twenty five long-distance runners aged 22-35 years. They were divided into two groups. In group 1 (n = 13) subjects performed the exercise "Vele's Forward Lean" and "Reverse Tandem Gait" and in Group 2 (n = 12) the "Short Foot Exercise." The runners performed the exercises daily for 6 weeks. The Foot Posture Index (FPI-6) and The Functional Movement Screen (FMS) tests were performed twice: at baseline and after 6 weeks of the exercise. A significant improvement was observed in FPI -6 (talar head palpation in Group 1, and inversion/eversion of the calcaneus in Group 2). Also in Group 1 a significant improvement was noted in FMS tests: deep squat, active straight leg raise and in total score. Short foot muscles strengthening exercises have beneficial effect on functional movement patterns and on foot posture, therefore they should be included as a part of daily training program of runners. Australian New Zealand Clinical Trials Registry ACTRN12615001200572.

Baicalin supplementation reduces serum biomarkers of skeletal muscle wasting and may protect against lean body mass reduction in cancer patients: Results from a pilot open-label study.

PubMed

Emanuele, Enzo; Bertona, Marco; Pareja-Galeano, Helios; Fiuza-Luces, Carmen; Morales, Javier Salvador; Sanchis-Gomar, Fabian; Lucia, Alejandro

2016-07-01

Muscle wasting in patients with cancer has been linked to an increased activity of nuclear factor κB (NF-κB) and higher circulating levels of activin-A (ActA), a negative growth factor for muscle mass. Baicalin is a natural flavonoid that can reduce skeletal muscle atrophy in animal models of cancer cachexia by inhibiting NF-κB. This pilot open-label study assessed the effects of baicalin supplementation (50 mg daily for 3 months) in cancer patients who showed involuntary weight loss >5% over the past 6 months. A total of 20 patients were investigated. Participants were evaluated at baseline and at the end of the 3-month study period for the following endpoints: 1) changes from baseline in serum NF-κB and ActA levels; and 2) change from baseline in lean body mass (LBM). We observed significant reduction in both NF-κB (p<0.05) and ActA (p<0.05) serum levels from baseline to 3 months. At 3 months, patients also showed a significant mean increase in LBM (+0.8 kg, p<0.05 compared with baseline). Our pilot open-label data suggest that baicalin supplementation is potentially useful for contrasting lean body mass reduction in cancer patients with involuntary weight loss, an effect which is likely mediated by the inhibition of negative growth factors for muscle mass.

Evaluation of CHANGE, an Involuntary Cognitive Program for High-Risk Inmates

ERIC Educational Resources Information Center

Hogan, Nancy L.; Lambert, Eric G.; Barton-Bellessa, Shannon M.

2012-01-01

Prison violence is a major concern in most correctional institutions. One intervention frequently used to reduce violent behavior is cognitive therapy. An involuntary cognitive program at a Midwestern state prison was evaluated for its impact on official misconduct. A total of 213 inmates were randomly assigned to the treatment (CHANGE) group (n =…

Brain Networks of Novelty-Driven Involuntary and Cued Voluntary Auditory Attention Shifting

PubMed Central

Huang, Samantha; Belliveau, John W.; Tengshe, Chinmayi; Ahveninen, Jyrki

2012-01-01

In everyday life, we need a capacity to flexibly shift attention between alternative sound sources. However, relatively little work has been done to elucidate the mechanisms of attention shifting in the auditory domain. Here, we used a mixed event-related/sparse-sampling fMRI approach to investigate this essential cognitive function. In each 10-sec trial, subjects were instructed to wait for an auditory “cue” signaling the location where a subsequent “target” sound was likely to be presented. The target was occasionally replaced by an unexpected “novel” sound in the uncued ear, to trigger involuntary attention shifting. To maximize the attention effects, cues, targets, and novels were embedded within dichotic 800-Hz vs. 1500-Hz pure-tone “standard” trains. The sound of clustered fMRI acquisition (starting at t = 7.82 sec) served as a controlled trial-end signal. Our approach revealed notable activation differences between the conditions. Cued voluntary attention shifting activated the superior intra­­parietal sulcus (IPS), whereas novelty-triggered involuntary orienting activated the inferior IPS and certain subareas of the precuneus. Clearly more widespread activations were observed during voluntary than involuntary orienting in the premotor cortex, including the frontal eye fields. Moreover, we found ­evidence for a frontoinsular-cingular attentional control network, consisting of the anterior insula, inferior frontal cortex, and medial frontal cortices, which were activated during both target discrimination and voluntary attention shifting. Finally, novels and targets activated much wider areas of superior temporal auditory cortices than shifting cues. PMID:22937153

Analysis of muscle activity and ankle joint movement during the side-hop test.

PubMed

Yoshida, Masahiro; Taniguchi, Keigo; Katayose, Masaki

2011-08-01

Functional performance tests (FPTs) that consist of movements, such as hopping, landing, and cutting, provide useful measurements. Although some tests have been established for kinematic studies of the knee joint, very few tests have been established for the ankle joint. To use the FPT as a test battery for patients with an ankle sprain, it is necessary to document typical patterns of muscle activation and range of motion (ROM) of the ankle joint during FPTs. Therefore, the purpose of this study was to investigate the pattern of the ROM of the ankle inversion/eversion and the muscle activity of the peroneus longus muscle (PL) and the tibial anterior muscle (TA) in normal subjects during the side-hop test. To emphasize the characteristics of ROM and electromyography (EMG) at each phase, the side-hop tests were divided into 4 phases: lateral-hop contact phase (LC), lateral-hop flight phase (LF), medial hop contact phase (MC), and medial hop flight phase (MF), and the ROM of ankle inversion/eversion, a peak angle of ankle inversion, and Integral EMG (IEMG) of PL and TA compared among 4 phases. Fifteen male subjects with no symptoms of ankle joint problems participated in this research. The ROM of ankle inversion/eversion during the side-hop test was 27 ± 3.8° (mean ± SD), and there was a significant difference in the ROM of ankle inversion/eversion among 4 phases (p < 0.05). The phase in which the widest ROM was presented was the MF. A peak angle of the ankle inversion at MC was significantly greater than at LC and MF (p <0.05). A peak angle of the ankle inversion at LF was significantly greater than at LC and MF. The PL remained contracting with 50-160% of maximal voluntary contraction (MVC). The IEMGs of PL in both the contact phases were significantly greater than in both the flight phases (p < 0.05). In addition, the PL activity at LC was significantly greater than at MC. The TA remained contracting at 50-80% of MVC through the side-hop test. The IEMG of TA at

Cooperative hand movements in post-stroke subjects: Neural reorganization.

PubMed

Schrafl-Altermatt, Miriam; Dietz, Volker

2016-01-01

Recent research indicates a task-specific neural coupling controlling cooperative hand movements reflected in bilateral electromyographic reflex responses in arm muscles following unilateral nerve stimulation. Reorganization of this mechanism was explored in post-stroke patients in this study. Electromyographic reflex responses in forearm muscles to unilateral electrical ulnar nerve stimulation were examined during cooperative and non-cooperative hand movements. Stimulation of the unaffected arm during cooperative hand movements led to electromyographic responses in bilateral forearm muscles, similar to those seen in healthy subjects, while stimulation of the affected side was followed only by ipsilateral responses. No contralateral reflex responses could be evoked in severely affected patients. The presence of contralateral responses correlated with the clinical motor impairment as assessed by the Fugl-Meyer test. The observations suggest that after stroke an impaired processing of afferent input from the affected side leads to a defective neural coupling and is associated with a greater involvement of fiber tracts from the unaffected hemisphere during cooperative hand movements. The mechanism of neural coupling underlying cooperative hand movements is shown to be defective in post-stroke patients. The neural re-organizations observed have consequences for the rehabilitation of hand function. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Night-to-Night Variability of Muscle Tone, Movements, and Vocalizations in Patients with REM Sleep Behavior Disorder

PubMed Central

Cygan, Fanny; Oudiette, Delphine; Leclair-Visonneau, Laurène; Leu-Semenescu, Smaranda; Arnulf, Isabelle

2010-01-01

Objectives: The video-polysomnographic criteria of REM sleep behavior disorder (RBD) have not been well described. We evaluated the between-night reproducibility of phasic and tonic enhanced muscle activity during REM sleep as well as the associated behaviors and vocalizations of the patients. Methods: Fifteen patients with clinical RBD underwent two consecutive video-polysomnographies. The amount of excessive phasic and tonic chin muscle activity during REM sleep was measured in 15 patients in 3-sec mini-epochs. The time spent with motor (minor, major, complex, and scenic) or vocal (sounds, mumblings, and comprehensible speeches) events was measured in 7 patients during REM sleep. Results: There was a good between-night agreement for tonic (Spearman rho = 0.55, p = 0.03; Kendall tau = 0.48, p = 0.01) but not for phasic (rho = 0.47, p = 0.1; tau = 0.31, p = 0.1) excessive chin muscle activity. On the video and audio recordings, the minor RBD behaviors tended to occur more frequently during the second night than the first, whereas the patients spoke longer during the first than the second night. Conclusion: The excessive tonic activity during REM sleep is a reliable marker of RBD. It could represent the extent of dysfunction in the permissive atonia systems. In contrast, the more variable phasic activity and motor/vocal events could be more dependent on dream content (executive systems). Citation: Cygan F; Oudiette D; Leclair-Visonneau L; Leu-Semenescu S; Arnulf I. Night-to-night variability of muscle tone, movements, and vocalizations in patients with REM sleep behavior disorder. J Clin Sleep Med 2010;6(6):551-555. PMID:21206543

The timing of control signals underlying fast point-to-point arm movements.

PubMed

Ghafouri, M; Feldman, A G

2001-04-01

It is known that proprioceptive feedback induces muscle activation when the facilitation of appropriate motoneurons exceeds their threshold. In the suprathreshold range, the muscle-reflex system produces torques depending on the position and velocity of the joint segment(s) that the muscle spans. The static component of the torque-position relationship is referred to as the invariant characteristic (IC). According to the equilibrium-point (EP) hypothesis, control systems produce movements by changing the activation thresholds and thus shifting the IC of the appropriate muscles in joint space. This control process upsets the balance between muscle and external torques at the initial limb configuration and, to regain the balance, the limb is forced to establish a new configuration or, if the movement is prevented, a new level of static torques. Taken together, the joint angles and the muscle torques generated at an equilibrium configuration define a single variable called the EP. Thus by shifting the IC, control systems reset the EP. Muscle activation and movement emerge following the EP resetting because of the natural physical tendency of the system to reach equilibrium. Empirical and simulation studies support the notion that the control IC shifts and the resulting EP shifts underlying fast point-to-point arm movements are gradual rather than step-like. However, controversies exist about the duration of these shifts. Some studies suggest that the IC shifts cease with the movement offset. Other studies propose that the IC shifts end early in comparison to the movement duration (approximately, at peak velocity). The purpose of this study was to evaluate the duration of the IC shifts underlying fast point-to-point arm movements. Subjects made fast (hand peak velocity about 1.3 m/s) planar arm movements toward different targets while grasping a handle. Hand forces applied to the handle and shoulder/elbow torques were, respectively, measured from a force sensor placed

Statins Affect Skeletal Muscle Performance: Evidence for Disturbances in Energy Metabolism.

PubMed

Allard, Neeltje A E; Schirris, Tom J J; Verheggen, Rebecca J; Russel, Frans G M; Rodenburg, Richard J; Smeitink, Jan A M; Thompson, Paul D; Hopman, Maria T E; Timmers, Silvie

2018-01-01

Statin myopathy is linked to disturbances in mitochondrial function and exercise intolerance. To determine whether differences exist in exercise performance, muscle function, and muscle mitochondrial oxidative capacity and content between symptomatic and asymptomatic statin users, and control subjects. Cross-sectional study. Department of Physiology, Radboud University Medical Center. Long-term symptomatic and asymptomatic statin users, and control subjects (n = 10 per group). Maximal incremental cycling tests, involuntary electrically stimulated isometric quadriceps-muscle contractions, and biopsy of vastus lateralis muscle. Maximal exercise capacity, substrate use during exercise, muscle function, and mitochondrial energy metabolism. Peak oxygen uptake, maximal work load, and ventilatory efficiency were comparable between groups, but both statin groups had a depressed anaerobic threshold compared with the control group (P = 0.01). Muscle relaxation time was prolonged in both statin groups compared with the control group and rate of maximal force rise was decreased (Ptime×group < 0.001 for both measures). Mitochondrial activity of complexes II and IV was lower in symptomatic statin users than control subjects and tended to be lower for complex (C) III (CII: P = 0.03; CIII: P = 0.05; CIV: P = 0.04). Mitochondrial content tended to be lower in both statin groups than in control subjects. Statin use attenuated substrate use during maximal exercise performance, induced muscle fatigue during repeated muscle contractions, and decreased muscle mitochondrial oxidative capacity. This suggests disturbances in mitochondrial oxidative capacity occur with statin use even in patients without statin-induced muscle complaints. Copyright © 2017 Endocrine Society

The Effect of Voluntary and Involuntary Residential Mobility on Females and Males

ERIC Educational Resources Information Center

Butler, Edgar W.; And Others

1973-01-01

The analysis suggests that for both males and females moving, whether voluntary or involuntary, decreases formal organizational participation, has little effect upon informal social relations either within or outside the neighborhood of residence, relatively small impact upon how respondents perceive their neighbors, and little effect upon the…

Movement-related and steady-state electromyographic activity of human elbow flexors in slow transition movements between two equilibrium states.

PubMed

Tal'nov, A N; Cherkassky, V L; Kostyukov, A I

1997-08-01

The electromyograms were recorded in healthy human subjects by surface electrodes from the mm. biceps brachii (caput longum et. brevis), brachioradialis, and triceps brachii (caput longum) during slow transition movements in elbow joint against a weak extending torque. The test movements (flexion transitions between two steady-states) were fulfilled under visual control through combining on a monitor screen a signal from a joint angle sensor with a corresponding command generated by a computer. Movement velocities ranged between 5 and 80 degrees/s, subjects were asked to move forearm without activation of elbow extensors. Surface electromyograms were full-wave rectified, filtered and averaged within sets of 10 identical tests. Amplitudes of dynamic and steady-state components of the electromyograms were determined in dependence on a final value of joint angle, slow and fast movements were compared. An exponential-like increase of dynamic component was observed in electromyograms recorded from m. biceps brachii, the component had been increased with movement velocity and with load increment. In many experiments a statistically significant decrease of static component could be noticed within middle range of joint angles (40-60 degrees) followed by a well expressed increment for larger movements. This pattern of the static component in electromyograms could vary in different experiments even in the same subjects. A steady discharge in m. brachioradialis at ramp phase has usually been recorded only under a notable load. Variable and quite often unpredictable character of the static components of the electromyograms recorded from elbow flexors in the transition movements makes it difficult to use the equilibrium point hypothesis to describe the central processes of movement. It has been assumed that during active muscle shortening the dynamic components in arriving efferent activity should play a predominant role. A simple scheme could be proposed for transition to a

Cerebro-Oculo-Facio-Skeletal Syndrome (COFS)

MedlinePlus

... clenched fists, wide-set nipples, vision impairments, involuntary eye movements, and impaired cognitive development, which can be moderate ... clenched fists, wide-set nipples, vision impairments, involuntary eye movements, and impaired cognitive development, which can be moderate ...

Finger muscle control in children with dystonia.

PubMed

Young, Scott J; van Doornik, Johan; Sanger, Terence D

2011-06-01

Childhood dystonia is a disorder that involves inappropriate muscle activation during attempts at voluntary movement. Few studies have investigated the muscle activity associated with dystonia in children, and none have done so in the hands. In this study, we measured surface electromyographic activity in four intrinsic hand muscles while participants attempted to perform an isometric tracking task using one of the muscles. Children with dystonia had greater tracking error with the task-related muscle and greater overflow to non-task muscles. Both tracking error and overflow correlated with the Barry-Albright Dystonia scale of the respective upper limb. Overflow also decreased when participants received visual feedback of non-task muscle activity. We conclude that two of the motor deficits in childhood dystonia--motor overflow and difficulties in actively controlling muscles--can be seen in the surface electromyographic activity of individual muscles during an isometric task. As expected from results in adults, overflow is an important feature of childhood dystonia. However, overflow may be at least partially dependent on an individual's level of awareness of their muscle activity. Most importantly, poor single-muscle tracking shows that children with dystonia have deficits of individual muscle control in addition to overflow or co-contraction. These results provide the first quantitative measures of the muscle activity associated with hand dystonia in children, and they suggest possible directions for control of dystonic symptoms. Copyright © 2011 Movement Disorder Society.

Decoding of Human Movements Based on Deep Brain Local Field Potentials Using Ensemble Neural Networks

PubMed Central

2017-01-01

Decoding neural activities related to voluntary and involuntary movements is fundamental to understanding human brain motor circuits and neuromotor disorders and can lead to the development of neuromotor prosthetic devices for neurorehabilitation. This study explores using recorded deep brain local field potentials (LFPs) for robust movement decoding of Parkinson's disease (PD) and Dystonia patients. The LFP data from voluntary movement activities such as left and right hand index finger clicking were recorded from patients who underwent surgeries for implantation of deep brain stimulation electrodes. Movement-related LFP signal features were extracted by computing instantaneous power related to motor response in different neural frequency bands. An innovative neural network ensemble classifier has been proposed and developed for accurate prediction of finger movement and its forthcoming laterality. The ensemble classifier contains three base neural network classifiers, namely, feedforward, radial basis, and probabilistic neural networks. The majority voting rule is used to fuse the decisions of the three base classifiers to generate the final decision of the ensemble classifier. The overall decoding performance reaches a level of agreement (kappa value) at about 0.729 ± 0.16 for decoding movement from the resting state and about 0.671 ± 0.14 for decoding left and right visually cued movements. PMID:29201041

Velocity-based planning of rapid elbow movements expands the control scheme of the equilibrium point hypothesis.

PubMed

Suzuki, Masataka; Yamazaki, Yoshihiko

2005-01-01

According to the equilibrium point hypothesis of voluntary motor control, control action of muscles is not explicitly computed, but rather arises as a consequence of interaction between moving equilibrium position, current kinematics and stiffness of the joint. This approach is attractive as it obviates the need to explicitly specify the forces controlling limb movements. However, many debatable aspects of this hypothesis remain in the manner of specification of the equilibrium point trajectory and muscle activation (or its stiffness), which elicits a restoring force toward the planned equilibrium trajectory. In this study, we expanded the framework of this hypothesis by assuming that the control system uses the velocity measure as the origin of subordinate variables scaling descending commands. The velocity command is translated into muscle control inputs by second order pattern generators, which yield reciprocal command and coactivation commands, and create alternating activation of the antagonistic muscles during movement and coactivation in the post-movement phase, respectively. The velocity command is also integrated to give a position command specifying a moving equilibrium point. This model is purely kinematics-dependent, since the descending commands needed to modulate the visco-elasticity of muscles are implicitly given by simple parametric specifications of the velocity command alone. The simulated movements of fast elbow single-joint movements corresponded well with measured data performed over a wide range of movement distances, in terms of both muscle excitations and kinematics. Our proposal on a synthesis for the equilibrium point approach and velocity command, may offer some insights into the control scheme of the single-joint arm movements.

Analysis of Facial Expression by Taste Stimulation

NASA Astrophysics Data System (ADS)

Tobitani, Kensuke; Kato, Kunihito; Yamamoto, Kazuhiko

In this study, we focused on the basic taste stimulation for the analysis of real facial expressions. We considered that the expressions caused by taste stimulation were unaffected by individuality or emotion, that is, such expressions were involuntary. We analyzed the movement of facial muscles by taste stimulation and compared real expressions with artificial expressions. From the result, we identified an obvious difference between real and artificial expressions. Thus, our method would be a new approach for facial expression recognition.

Automatic gain control of neural coupling during cooperative hand movements.

PubMed

Thomas, F A; Dietz, V; Schrafl-Altermatt, M

2018-04-13

Cooperative hand movements (e.g. opening a bottle) are controlled by a task-specific neural coupling, reflected in EMG reflex responses contralateral to the stimulation site. In this study the contralateral reflex responses in forearm extensor muscles to ipsilateral ulnar nerve stimulation was analyzed at various resistance and velocities of cooperative hand movements. The size of contralateral reflex responses was closely related to the level of forearm muscle activation required to accomplish the various cooperative hand movement tasks. This indicates an automatic gain control of neural coupling that allows a rapid matching of corrective forces exerted at both sides of an object with the goal 'two hands one action'.

Evaluating the Impact of Policies to Regulate Involuntary Out-of-Network Charges on New Jersey Hospitals.

PubMed

Mattke, Soeren; White, Chapin; Hanson, Mark; Kotzias, Virginia I

2017-01-01

Policymakers must balance the complex and sometimes conflicting objectives of ensuring access to care, limiting the financial burden on patients, and controlling overall costs. States differ in how they handle involuntary out-of-network charges-i.e., payment for care when a patient does not have the option of selecting a hospital in his or her health plan's network. New Jersey's current regulations emphasize patient protection, in that patients are only responsible for the portion of the cost that they would have incurred for in-network care, and health plans must pay the remainder of the provider's charges. This policy is seen as contentious by health plans, who argue that they have been made responsible for paying whatever charges a hospital submits, and proposals to limit payments for involuntary out-of-network care are being debated in the state legislature. This study seeks to inform the current debate (as of October 2016) by analyzing the role of out-of-network payments in New Jersey hospitals' financial performance and simulating the effect of policies to limit charges for involuntary out-of-network care. The authors' estimates suggest that implementing New Jersey Bill A1952, which proposes a limit of between 90 and 200 percent of Medicare rates for involuntary out-of-network hospital care, would have reduced payments for hospital care by commercial plans by between 6 and 10 percent during 2010 through 2014. Assuming no change in operating expenses and no recoupment of lost out-of-network revenues, the cap would have led to an operating loss at between 48 and 70 percent of hospitals.

Association of Cost Sharing With Mental Health Care Use, Involuntary Commitment, and Acute Care.

PubMed

Ravesteijn, Bastian; Schachar, Eli B; Beekman, Aartjan T F; Janssen, Richard T J M; Jeurissen, Patrick P T

2017-09-01

A higher out-of-pocket price for mental health care may lead not only to cost savings but also to negative downstream consequences. To examine the association of higher patient cost sharing with mental health care use and downstream effects, such as involuntary commitment and acute mental health care use. This difference-in-differences study compared changes in mental health care use by adults, who experienced an increase in cost sharing, with changes in youths, who did not experience the increase and thus formed a control group. The study examined all 2 780 558 treatment records opened from January 1, 2010, through December 31, 2012, by 110 organizations that provide specialist mental health care in the Netherlands. Data analysis was performed from January 18, 2016, to May 9, 2017. On January 1, 2012, the Dutch national government increased the out-of-pocket price of mental health services for adults by up to €200 (US$226) per year for outpatient treatment and €150 (US$169) per month for inpatient treatment. The number of treatment records opened each day in regular specialist mental health care, involuntary commitment, and acute mental health care, and annual specialist mental health care spending. This study included 1 448 541 treatment records opened from 2010 to 2012 (mean [SD] age, 41.4 [16.7] years; 712 999 men and 735 542 women). The number of regular mental health care records opened for adults decreased abruptly and persistently by 13.4% (95% CI, -16.0% to -10.8%; P < .001) per day when cost sharing was increased in 2012. The decrease was substantial and significant for severe and mild disorders and larger in low-income than in high-income neighborhoods. Simultaneously, in 2012, daily record openings increased for involuntary commitment by 96.8% (95% CI, 87.7%-105.9%; P < .001) and for acute mental health care by 25.1% (95% CI, 20.8%-29.4%; P < .001). In contrast to our findings for adults, the use of regular care among youths

[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.

Do Differences in Levels, Types, and Duration of Muscle Contraction Have an Effect on the Degree of Post-exercise Depression?

PubMed

Miyaguchi, Shota; Kojima, Sho; Kirimoto, Hikari; Tamaki, Hiroyuki; Onishi, Hideaki

2016-01-01

We conducted two experiments to determine how differences in muscle contraction levels, muscle contraction types, and movement duration affect degree of post-exercise depression (PED) after non-exhaustive, repetitive finger movement. Twelve healthy participants performed repetitive abduction movements of the right index finger at 2 Hz. In experiment 1, we examined the effects of muscle contraction levels at 10, 20, and 30% maximum voluntary contraction and the effects of muscle contraction types at isotonic and isometric contraction. In experiment 2, we examined the effects of movement duration at 2 and 6 min. Motor-evoked potentials (MEPs) were recorded from the right first dorsal interosseous muscle before movement tasks and 1-10 min after movement tasks. MEP amplitudes after isotonic contraction tasks were significantly smaller than those after isometric contraction tasks and decreased with increasing contraction levels, but were independent of movement duration. This study demonstrated that the degree of PED after non-exhaustive repetitive finger movement depended on muscle contraction levels and types. Thus, the degree of PED may depend on the levels of activity in the motor cortex during a movement task. This knowledge will aid in the design of rehabilitation protocols.

Voluntary and involuntary driving cessation in later life.

PubMed

Choi, Moon; Mezuk, Briana; Rebok, George W

2012-01-01

This study explores the decision-making process of driving cessation in later life, with a focus on voluntariness. The sample included 83 former drivers from the Baltimore Epidemiologic Catchment Area Study. A majority of participants (83%) reportedly stopped driving by their own decision. However, many voluntary driving retirees reported external factors such as financial difficulty, anxiety about driving, or lack of access to a car as main reasons for driving cessation. These findings imply that distinction between voluntary and involuntary driving cessation is ambiguous and that factors beyond health status, including financial strain, play a role in the transition to non-driving.

Muscle cocontraction following dynamics learning.

PubMed

Darainy, Mohammad; Ostry, David J

2008-09-01

Coactivation of antagonist muscles is readily observed early in motor learning, in interactions with unstable mechanical environments and in motor system pathologies. Here we present evidence that the nervous system uses coactivation control far more extensively and that patterns of cocontraction during movement are closely tied to the specific requirements of the task. We have examined the changes in cocontraction that follow dynamics learning in tasks that are thought to involve finely sculpted feedforward adjustments to motor commands. We find that, even following substantial training, cocontraction varies in a systematic way that depends on both movement direction and the strength of the external load. The proportion of total activity that is due to cocontraction nevertheless remains remarkably constant. Moreover, long after indices of motor learning and electromyographic measures have reached asymptotic levels, cocontraction still accounts for a significant proportion of total muscle activity in all phases of movement and in all load conditions. These results show that even following dynamics learning in predictable and stable environments, cocontraction forms a central part of the means by which the nervous system regulates movement.

Involuntary detention and treatment of the mentally ill: China's 2012 Mental Health Law.

PubMed

Ding, Chunyan

2014-01-01

The long-awaited Mental Health Law of China was passed on 26 October 2012 and took effect on 1 May 2013. Being the first national legislation on mental health, it establishes a basic legal framework to regulate mental health practice and recognizes the fundamental rights of persons with mental disorders. This article focuses on the system of involuntary detention and treatment of the mentally ill under the new law, which is expected to prevent the so-called "Being misidentified as mentally disordered" cases in China. A systematic examination of the new system demonstrates that the Mental Health Law of China implicitly holds two problematic assumptions and does not provide adequate protection of the fundamental rights of the involuntary patients. Administrative enactments and further national legislative efforts are needed to remedy these flaws in the new law. Copyright © 2014 Elsevier Ltd. All rights reserved.

78 FR 23782 - Renewal of Agency Information Collection for Appointed Counsel in Involuntary Indian Child...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-22

... OMB Control Number 1076-0111. This information collection expires May 31, 2013. DATE: Interested.... Data OMB Control Number: 1076-0111. Title: Payment for Appointed Counsel in Involuntary Indian Child...

75 FR 7514 - Renewal of Agency Information Collection for Appointed Counsel in Involuntary Indian Child...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-19

.... The information collection is currently authorized by OMB Control Number 1076-0111, which expires.... III. Data OMB Control Number: 1076-0111. Title: Payment for Appointed Counsel in Involuntary Indian...

Pathophysiology of dysarthria in cerebral palsy.

PubMed Central

Neilson, P D; O'Dwyer, N J

1981-01-01

Electromyograms were recorded with hooked-wire electrodes from sixteen lip, tongue and jaw muscles in six normal and seven cerebral palsied adult subjects during a variety of speech and non-speech tasks. The recorded patterns of muscle activity fail to support a number of theories concerning the pathophysiology of dysarthria in cerebral palsy. There was no indication of weakness in individual articulator muscles. There was no evidence of uncontrolled sustained background activity or of abnormal tonic stretch reflex responses in lip or tongue muscles. Primitive or pathological reflexes could not be elicited by orofacial stimulation. No imbalance between positive and negative oral responses was observed. The view that random involuntary movement disrupts essentially normal voluntary control in athetosis was not supported. Each cerebral palsied subject displayed an idiosyncratic pattern of abnormal muscle activity which was reproduced across repetitions of the same phrase, indicating a consistent defect in motor programming. PMID:7334387

Automatic prediction of tongue muscle activations using a finite element model.

PubMed

Stavness, Ian; Lloyd, John E; Fels, Sidney

2012-11-15

Computational modeling has improved our understanding of how muscle forces are coordinated to generate movement in musculoskeletal systems. Muscular-hydrostat systems, such as the human tongue, involve very different biomechanics than musculoskeletal systems, and modeling efforts to date have been limited by the high computational complexity of representing continuum-mechanics. In this study, we developed a computationally efficient tracking-based algorithm for prediction of muscle activations during dynamic 3D finite element simulations. The formulation uses a local quadratic-programming problem at each simulation time-step to find a set of muscle activations that generated target deformations and movements in finite element muscular-hydrostat models. We applied the technique to a 3D finite element tongue model for protrusive and bending movements. Predicted muscle activations were consistent with experimental recordings of tongue strain and electromyography. Upward tongue bending was achieved by recruitment of the superior longitudinal sheath muscle, which is consistent with muscular-hydrostat theory. Lateral tongue bending, however, required recruitment of contralateral transverse and vertical muscles in addition to the ipsilateral margins of the superior longitudinal muscle, which is a new proposition for tongue muscle coordination. Our simulation framework provides a new computational tool for systematic analysis of muscle forces in continuum-mechanics models that is complementary to experimental data and shows promise for eliciting a deeper understanding of human tongue function. Copyright © 2012 Elsevier Ltd. All rights reserved.

Paraneoplastic autoimmune movement disorders.

PubMed

Lim, Thien Thien

2017-11-01

To provide an overview of paraneoplastic autoimmune disorders presenting with various movement disorders. The spectrum of paraneoplastic autoimmune disorders has been expanding with the discovery of new antibodies against cell surface and intracellular antigens. Many of these paraneoplastic autoimmune disorders manifest as a form of movement disorder. With the discovery of new neuronal antibodies, an increasing number of idiopathic or neurodegenerative movement disorders are now being reclassified as immune-mediated movement disorders. These include anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis which may present with orolingual facial dyskinesia and stereotyped movements, CRMP-5 IgG presenting with chorea, anti-Yo paraneoplastic cerebellar degeneration presenting with ataxia, anti-VGKC complex (Caspr2 antibodies) neuromyotonia, opsoclonus-myoclonus-ataxia syndrome, and muscle rigidity and episodic spasms (amphiphysin, glutamic acid decarboxylase, glycine receptor, GABA(A)-receptor associated protein antibodies) in stiff-person syndrome. Movement disorders may be a presentation for paraneoplastic autoimmune disorders. Recognition of these disorders and their common phenomenology is important because it may lead to the discovery of an occult malignancy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prediction of muscle activation for an eye movement with finite element modeling.

PubMed

Karami, Abbas; Eghtesad, Mohammad; Haghpanah, Seyyed Arash

2017-10-01

In this paper, a 3D finite element (FE) modeling is employed in order to predict extraocular muscles' activation and investigate force coordination in various motions of the eye orbit. A continuum constitutive hyperelastic model is employed for material description in dynamic modeling of the extraocular muscles (EOMs). Two significant features of this model are accurate mass modeling with FE method and stimulating EOMs for motion through muscle activation parameter. In order to validate the eye model, a forward dynamics simulation of the eye motion is carried out by variation of the muscle activation. Furthermore, to realize muscle activation prediction in various eye motions, two different tracking-based inverse controllers are proposed. The performance of these two inverse controllers is investigated according to their resulted muscle force magnitude and muscle force coordination. The simulation results are compared with the available experimental data and the well-known existing neurological laws. The comparison authenticates both the validation and the prediction results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rates of unemployment and incidence of police-initiated examinations for involuntary hospitalization in Florida.

PubMed

Kessell, Eric R; Catalano, Ralph A; Christy, Annette; Monahan, John

2006-10-01

This study tested the hypothesis that contraction of regional economies affects the incidence of involuntary admissions to psychiatric emergency services by reducing community tolerance for persons perceived as threatening to others. This hypothesis was tested with time-series analyses of the relationship between initial claims for unemployment in Florida between July 4, 1999, and June 28, 2003, and the weekly number of men and women presented by police to be examined for involuntary psychiatric hospitalization because of danger to others. The analyses controlled for admissions presented by mental health professionals because of danger to others and for admissions presented by police because of neglect or disability. When the analyses controlled for autocorrelation and other covariates, claims for unemployment insurance were significantly associated with the number of men presented by police for danger to others. During the study period, police presented 5,897 men for examination because of danger to others. Increased unemployment claims were associated with approximately 309 more men being presented for examination than expected from prior presentation rates and from the number presented by mental health professionals for danger to others and by police for neglect or disability. No such association was found for women. Consistent with theory, this study found that presentations for involuntary admission to psychiatric services increased after contractions in the labor market. Combining the methods of this study with econometric forecasting may allow providers to anticipate better the need for psychiatric services.

The punctum fixum-punctum mobile model: a neuromuscular principle for efficient movement generation?

PubMed

von Laßberg, Christoph; Rapp, Walter

2015-01-01

According to the "punctum fixum-punctum mobile model" that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum) toward the body part that shall be accelerated (punctum mobile). The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline), as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum) has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]). The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning procedures of context

The Punctum Fixum-Punctum Mobile Model: A Neuromuscular Principle for Efficient Movement Generation?

PubMed Central

von Laßberg, Christoph; Rapp, Walter

2015-01-01

According to the “punctum fixum–punctum mobile model” that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum) toward the body part that shall be accelerated (punctum mobile). The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline), as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum) has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]). The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning procedures of

Kinesthetic illusions attenuate experimental muscle pain, as do muscle and cutaneous stimulation.

PubMed

Gay, André; Aimonetti, Jean-Marc; Roll, Jean-Pierre; Ribot-Ciscar, Edith

2015-07-30

In the present study, muscle pain was induced experimentally in healthy subjects by administrating hypertonic saline injections into the tibialis anterior (TA) muscle. We first aimed at comparing the analgesic effects of mechanical vibration applied to either cutaneous or muscle receptors of the TA or to both types simultaneously. Secondly, pain alleviation was compared in subjects in whom muscle tendon vibration evoked kinesthetic illusions of the ankle joint. Muscle tendon vibration, which primarily activated muscle receptors, reduced pain intensity by 30% (p<0.01). In addition, tangential skin vibration reduced pain intensity by 33% (p<0.01), primarily by activating cutaneous receptors. Concurrently stimulating both sensory channels induced stronger analgesic effects (-51%, p<0.01), as shown by the lower levels of electrodermal activity. The strongest analgesic effects of the vibration-induced muscle inputs occurred when illusory movements were perceived (-38%, p=0.01). The results suggest that both cutaneous and muscle sensory feedback reduce muscle pain, most likely via segmental and supraspinal processes. Further clinical trials are needed to investigate these new methods of muscle pain relief. Copyright © 2015 Elsevier B.V. All rights reserved.

From mind wandering to involuntary retrieval: Age-related differences in spontaneous cognitive processes.

PubMed

Maillet, David; Schacter, Daniel L

2016-01-08

The majority of studies that have investigated the effects of healthy aging on cognition have focused on age-related differences in voluntary and deliberately engaged cognitive processes. Yet many forms of cognition occur spontaneously, without any deliberate attempt at engaging them. In this article we review studies that have assessed age-related differences in four such types of spontaneous thought processes: mind-wandering, involuntary autobiographical memory, intrusive thoughts, and spontaneous prospective memory retrieval. These studies suggest that older adults exhibit a reduction in frequency of both mind-wandering and involuntary autobiographical memory, whereas findings regarding intrusive thoughts have been more mixed. Additionally, there is some preliminary evidence that spontaneous prospective memory retrieval may be relatively preserved in aging. We consider the roles of age-related differences in cognitive resources, motivation, current concerns and emotional regulation in accounting for these findings. We also consider age-related differences in the neural correlates of spontaneous cognitive processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

From mind wandering to involuntary retrieval: Age-related differences in spontaneous cognitive processes

PubMed Central

Maillet, David; Schacter, Daniel L.

2015-01-01

The majority of studies that have investigated the effects of healthy aging on cognition have focused on age-related differences in voluntary and deliberately engaged cognitive processes. Yet many forms of cognition occur spontaneously, without any deliberate attempt at engaging them. In this article we review studies that have assessed age-related differences in four such types of spontaneous thought processes: mind-wandering, involuntary autobiographical memory, intrusive thoughts, and spontaneous prospective memory retrieval. These studies suggest that older adults exhibit a reduction in frequency of both mind-wandering and involuntary autobiographical memory, whereas findings regarding intrusive thoughts have been more mixed. Additionally, there is some preliminary evidence that spontaneous prospective memory retrieval may be relatively preserved in aging. We consider the roles of age-related differences in cognitive resources, motivation, current concerns and emotional regulation in accounting for these findings. We also consider age-related differences in the neural correlates of spontaneous cognitive processes. PMID:26617263

Feedback Information and Analysis for Microprocessor Controlled Muscle Stimulation.

DTIC Science & Technology

1981-12-01

muscle into fiberous tissue (Guyton, 1976) is not inevitable. The contractile power can be preserved and fiberous build-up reduced by electrical... isometric tension, velocity of contraction and coordination of movement, all with minimally induced muscle fatigue. The work of Petrofsky and Phillips... muscle . Each muscle fiber is innervated by only a single nerve, but a single motor nerve fiber branches to as many as thousands of different muscle

Balance and muscle power of children with Charcot-Marie-Tooth.

PubMed

Silva, Tais R; Testa, Amanda; Baptista, Cyntia R J A; Marques, Wilson; Mattiello-Sverzut, Ana C

2014-01-01

In certain diseases, functional constraints establish a greater relationship with muscle power than muscle strength. However, in hereditary peripheral polyneuropathies, no such relationship was found in the literature. In children with Charcot-Marie-Tooth (CMT), to identify the impact of muscle strength and range of movement on the static/dynamic balance and standing long jump based on quantitative and functional variables. The study analyzed 19 participants aged between 6 and 16 years, of both genders and with clinical diagnoses of CMT of different subtypes. Anthropometric data, muscle strength of the lower limbs (hand-held dynamometer), ankle and knee range of movement, balance (Pediatric Balance Scale) and standing long jump distance were obtained by standardized procedures. For the statistical analysis, Pearson and Spearman correlation coefficients were used. There was a strong positive correlation between balance and the muscle strength of the right plantar flexors (r=0.61) and dorsiflexors (r=0.59) and a moderate correlation between balance and the muscle strength of inversion (r=0.41) and eversion of the right foot (r=0.44). For the long jump and range of movement, there was a weak positive correlation with right and left plantar flexion (r=0.20 and r=0.12, respectively) and left popliteal angle (r=0.25), and a poor negative correlation with left dorsiflexion (r=-0.15). The data on the patients analyzed suggests that the maintenance of distal muscle strength favors performance during balance tasks, while limitations in the range of movement of the legs seem not to be enough to influence the performance of the horizontal long jump.

Non-voluntary and involuntary euthanasia in The Netherlands: Dutch perspectives.

PubMed

Cohen-Almagor, Raphael

2003-01-01

During the summer of 1999, twenty-eight interviews with some of the leading authorities on euthanasia policy were conducted in the Netherlands. They were asked about cases of non-voluntary (when patients are incompetent) and involuntary euthanasia (when patients are competent and made no request to die). This study reports the main findings, showing that most respondents are quite complacent with regard to breaches of the guideline that require the patient's consent as a prerequisite to performance of euthanasia.

Muscle spindle autogenetic inhibition in the extraocular muscles of lamb.

PubMed

Pettorossi, V E; Filippi, G M

1981-09-01

The role of extraocular muscle (EOM) proprioceptors on eye motility has been investigated in lambs on "encéphale isolé", by evaluating the tension of EOMs at various lengths and velocities of stretch before and after proprioceptive blocks. The EOM tension, in the absence of proprioceptive input, was higher than in normal conditions. Such an effect occurred at lengthening values greater than 3 mm of stretch from resting muscle length, corresponding to 18 degrees of eye deviation and was dependent on the velocity of the stretch, being more effective at high velocity. The muscle receptors responsible for this effect was determined by comparing the sensitivity to vibratory stimulation of spindles and tendon organs to the amount of inhibition provoked by the same stimulation on an EOM electromyographic activity. The tension inhibition appeared to be correlated to muscle spindle activation. Thus, the presence of muscle spindles can determine a reduction of the tension within the stretched muscles. This result suggests that the EOM length and velocity signals operate moment to moment reduction on the stiffness of the muscle which antagonizes eye displacement, thus facilitating the ocular movements.

Influence of pelvic floor muscle fatigue on stress urinary incontinence: a systematic review.

PubMed

Thomaz, Rafaela Prusch; Colla, Cássia; Darski, Caroline; Paiva, Luciana Laureano

2018-02-01

Stress urinary incontinence (SUI) is the most common urinary complaint among women and is defined by the International Continence Society as any involuntary loss of urine due to physical effort, sneezing or coughing. Many women with SUI state that the loss of urine occurs after performing repetitive movements, which may suggest that it is the result of fatigue of the pelvic floor muscles (PFM). Thus, we performed the systematic review of the literature on the influence of PFM fatigue on the development or worsening of the symptoms of SUI in women. The PubMed, Scopus, EMBASE, PEDro, LILACS, SciELO, Cochrane Library, Google Scholar, CINAHL and Periódicos CAPES databases were searched for articles using the keywords "fatigue", "pelvic floor", "stress urinary incontinence" and "women", in Portuguese and in English. Methodological quality was assessed using the Downs and Black scale, and the data collected from the studies were analyzed descriptively. Of the 2,010 articles found, five met the inclusion criteria and were analyzed. They were published between 2004 and 2015, and included a total of 30,320 women with ages ranging from 24 to 53.6 years. Of the studies analyzed, three showed an association between fatigue and SUI, and two did not show such an association. This study confirmed that PFM fatigue can influence the development and/or worsening of SUI.

The oculomotor system of decapod cephalopods: eye muscles, eye muscle nerves, and the oculomotor neurons in the central nervous system.

PubMed

Budelmann, B U; Young, J Z

1993-04-29

Fourteen extraocular eye muscles are described in the decapods Loligo and Sepioteuthis, and thirteen in Sepia; they are supplied by four eye muscle nerves. The main action of most of the muscles is a linear movement of the eyeball, only three muscles produce strong rotations. The arrangement, innervation and action of the decapod eye muscles are compared with those of the seven eye muscles and seven eye muscle nerves in Octopus. The extra muscles in decapods are attached to the anterior and superior faces of the eyes. At least, the anterior muscles, and presumably also the superior muscles, are concerned with convergent eye movements for binocular vision during fixation and capture of prey by the tentacles. The remaining muscles are rather similar in the two cephalopod groups. In decapods, the anterior muscles include conjunctive muscles; these cross the midline and each presumably moves both eyes at the same time during fixation. In the squids Loligo and Sepioteuthis there is an additional superior conjunctive muscle of perhaps similar function. Some of the anterior muscles are associated with a narrow moveable plate, the trochlear cartilage; it is attached to the eyeball by trochlear membranes. Centripetal cobalt fillings showed that all four eye muscle nerves have fibres that originate from somata in the ipsilateral anterior lateral pedal lobe, which is the oculomotor centre. The somata of the individual nerves show different but overlapping distributions. Bundles of small presumably afferent fibres were seen in two of the four nerves. They do not enter the anterior lateral pedal lobe but run to the ventral magnocellular lobe; some afferent fibres enter the brachio-palliovisceral connective and run perhaps as far as the palliovisceral lobe.

Tardive dyskinesia successfully treated with alprazolam.

PubMed Central

Jordan, H. W.; Williams, B. C.

1990-01-01

Tardive dyskinesia is a disorder secondary to prolonged treatment (from 18 months to 3 years) with antipsychotic agents, affecting approximately 15% to 20% of patients. Tardive dyskinesia is characterized by difficulty controlling involuntary movements of the small muscle groups, producing tic-like reactions, muscle rigidity, and difficulty maintaining muscle tone. It is a chronic and unrelenting disorder which may be permanent if not successfully treated. The mechanism of action is thought to be secondary to dopamine hypersensitivity resulting from prolonged deprivation of dopamine on the part of dopamine-sensitive receptors. Theoretically, these receptors have been deprived of the neurotransmitter by chronic treatment with antipsychotic drugs, which are recognized as dopamine-blocking agents. We present a case in which alprazolam was successfully used in treating tardive dyskinesia. PMID:2213917

Kinematic and electromyographic analysis of the push movement in tai chi

PubMed Central

Chan, S; Luk, T; Hong, Y

2003-01-01

Background: Tai chi is a form of exercise derived from the martial art folk traditions of China. The force used in tai chi includes different principles of mechanical advantage. No studies on the kinematic features of tai chi exercise have been published. Objective: To analyse the kinematics and electromyographic characteristics of tai chi. Methods: An experienced tai chi master was asked to perform a sequence of basic movements: ward off, roll back, press, and push. The movements were videotaped and digitised using a motion analysis system. Electromyographic activities of the lumbar erector spinae, rectus femoris, medial hamstrings, and medial head of gastrocnemius were recorded by surface electrodes. The push movement data were analysed. Results: The medial hamstrings and medial head of gastrocnemius muscle groups maintained low activity, with higher electromyographic values in the lumbar erector spinae and substantially higher ones in the rectus femoris during the push movement. Both concentric and eccentric contractions occurred in muscles of the lower limbs, with eccentric contraction occurring mainly in the anti-gravity muscles such as the rectus femoris and the medial head of gastrocnemius. The forward and backward shifts in centre of gravity (CG) were mainly accomplished by increasing and decreasing respectively the joint angles of the bilateral lower limbs rather than by adopting a forward or backward postural lean. The path of the CG in the anteroposterior and mediolateral component was unique, and the sway or deviation from the path was small. The master maintained an upright posture and maintained a low CG (hips, knees, and ankles bent) while travelling slowly and steadily from one position to another. Conclusion: The eccentric muscle contraction of the lower limbs in the push movement of tai chi may help to strengthen the muscles. PMID:12893721

Local Muscle Fatigue and 3D Kinematics of the Cervical Spine in Healthy Subjects.

PubMed

Niederer, Daniel; Vogt, Lutz; Pippig, Torsten; Wall, Rudolf; Banzer, Winfried

2016-01-01

The authors aimed to further explore the effects of local muscle fatigue on cervical 3D kinematics and the interrelationship between these kinematic characteristics and local muscle endurance capacity in the unimpaired cervical spine. Twenty healthy subjects (38 ± 10 years; 5 women) performed 2 × 10 maximal cervical flexion-extension movements. Isometric muscle endurance tests (prone/supine lying) were applied between sets to induce local muscle fatigue quantified by Borg scale rates of perceived exertion (RPE) and slope in mean power frequency (MPF; surface electromyography; m. sternocleidomastoideus, m. splenius capitis). Cervical motion characteristics (maximal range of motion [ROM], coefficient of variation of the 10 repetitive movements, mean angular velocity, conjunct movements in transversal and frontal plane) were calculated from raw 3D ultrasonic movement data. Average isometric strength testing duration for flexion and extension correlated to the cervical ROM (r = .49/r = .48; p < .05). However, Student's t test demonstrated no significant alterations in any kinematic parameter following local muscle fatigue (p > .05). Although subjects' cervical muscle endurance capacity and motor output seems to be conjugated, no impact of local cervical muscle fatigue on motor function was shown. These findings underline the importance of complementary measures to address muscular performance and kinematic characteristics in outcome assessment and functional rehabilitation of the cervical spine.

[Myokymia].