Science.gov

Sample records for active arm movements

  1. 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. PMID:9671683

  2. Cortical Spectral Activity and Connectivity during Active and Viewed Arm and Leg Movement

    PubMed Central

    Kline, Julia E.; Huang, Helen J.; Snyder, Kristine L.; Ferris, Daniel P.

    2016-01-01

    Active and viewed limb movement activate many similar neural pathways, however, to date most comparison studies have focused on subjects making small, discrete movements of the hands and feet. The purpose of this study was to determine if high-density electroencephalography (EEG) could detect differences in cortical activity and connectivity during active and viewed rhythmic arm and leg movements in humans. Our primary hypothesis was that we would detect similar but weaker electrocortical spectral fluctuations and effective connectivity fluctuations during viewed limb exercise compared to active limb exercise due to the similarities in neural recruitment. A secondary hypothesis was that we would record stronger cortical spectral fluctuations for arm exercise compared to leg exercise, because rhythmic arm exercise would be more dependent on supraspinal control than rhythmic leg exercise. We recorded EEG data while ten young healthy subjects exercised on a recumbent stepper with: (1) both arms and legs, (2) just legs, and (3) just arms. Subjects also viewed video playback of themselves or another individual performing the same exercises. We performed independent component analysis, dipole fitting, spectral analysis, and effective connectivity analysis on the data. Cortical areas comprising the premotor and supplementary motor cortex, the anterior cingulate, the posterior cingulate, and the parietal cortex exhibited significant spectral fluctuations during rhythmic limb exercise. These fluctuations tended to be greater for the arms exercise conditions than for the legs only exercise condition, which suggests that human rhythmic arm movements are under stronger cortical control than rhythmic leg movements. We did not find consistent spectral fluctuations in these areas during the viewed conditions, but effective connectivity fluctuated at harmonics of the exercise frequency during both active and viewed rhythmic limb exercise. The right premotor and supplementary motor

  3. Human cervical spinal cord circuitry activated by tonic input can generate rhythmic arm movements.

    PubMed

    Solopova, I A; Selionov, V A; Zhvansky, D S; Gurfinkel, V S; Ivanenko, Y

    2016-02-01

    The coordination between arms and legs during human locomotion shares many features with that in quadrupeds, yet there is limited evidence for the central pattern generator for the upper limbs in humans. Here we investigated whether different types of tonic stimulation, previously used for eliciting stepping-like leg movements, may evoke nonvoluntary rhythmic arm movements. Twenty healthy subjects participated in this study. The subject was lying on the side, the trunk was fixed, and all four limbs were suspended in a gravity neutral position, allowing unrestricted low-friction limb movements in the horizontal plane. The results showed that peripheral sensory stimulation (continuous muscle vibration) and central tonic activation (postcontraction state of neuronal networks following a long-lasting isometric voluntary effort, Kohnstamm phenomenon) could evoke nonvoluntary rhythmic arm movements in most subjects. In ∼40% of subjects, tonic stimulation elicited nonvoluntary rhythmic arm movements together with rhythmic movements of suspended legs. The fact that not all participants exhibited nonvoluntary limb oscillations may reflect interindividual differences in responsiveness of spinal pattern generation circuitry to its activation. The occurrence and the characteristics of induced movements highlight the rhythmogenesis capacity of cervical neuronal circuitries, complementing the growing body of work on the quadrupedal nature of human gait. PMID:26683072

  4. The influence of body posture, arm movement, and work stress on trapezius activity during computer work.

    PubMed

    Mork, Paul Jarle; Westgaard, Rolf H

    2007-11-01

    The study aimed to determine the influence of arm posture and movement on trapezius activity of computer workers, considering the full workday. A second aim was to investigate if work periods perceived as stressful were associated with elevated or more sustained muscle activity pattern. Twenty-six computer workers performing call-center (n=11), help desk (n=7), or secretarial (n=8) work tasks participated. Bilateral trapezius surface electromyographic (sEMG) activity and heart rate was recorded throughout the workday. Simultaneous inclinometer recordings from left thigh and upper arms identified periods with sitting, standing, and walking, as well as arm posture and movement. Perceived work stress and tension were recorded on visual analog scales (VAS) every hour. Trapezius sEMG activity was low in seated posture [group median 1.8 and 0.9% of activity at maximal voluntary contraction (%EMGmax) for dominant and non-dominant side] and was elevated in standing (3.0 and 2.5% EMGmax) and walking (3.9 and 3.4% EMGmax). In seated posture (mean duration 79% of workday) arm movement consistently influenced trapezius activity, accounting for approximately 20% of intra-individual variation in trapezius activity. Arm elevation was on average not associated with trapezius activity when seated; however, considerable individual variation was observed. There was no indication of increase in trapezius activity or more sustained activity pattern, nor in heart rate, in high-stress versus low-stress periods, comparing periods with seated posture for the subjects reporting contrasts of at least two VAS units in stress (n=16) or tension (n=14) score. PMID:17653757

  5. Arm hand skilled performance in cerebral palsy: activity preferences and their movement components

    PubMed Central

    2014-01-01

    Background Assessment of arm-hand use is very important in children with cerebral palsy (CP) who encounter arm-hand problems. To determine validity and reliability of new instruments to assess actual performance, a set of standardized test situations including activities of daily living (ADL) is required. This study gives information with which such a set for upper extremity skill research may be fine-tuned, relative to a specific research question. Aim of this study is to a) identify upper extremity related ADL children with CP want to improve on, b) determine the 10 most preferred goals of children with CP, and c) identify movement components of all goals identified. Method The Canadian Occupational Performance Measure was used to identify upper extremity-related ADL preferences (goals) of 53 children with CP encountering arm-hand problems (mean age 9 ± 4.5 year). Goals were ranked based on importance attributed to each goal and the number of times a goal was mentioned, resulting in a gross list with goals. Additionally, two studies were performed, i.e. study A to determine the 10 most preferred goals for 3 age groups (2.5-5 years; 6-11 years, 12-19 years), based on the total preference score, and study B to identify movement components, like reaching and grasping, of all goals identified for both the leading and the assisting arm-hand. Results Seventy-two goals were identified. The 10 most preferred goals differed with age, changing from dressing and leisure-related goals in the youngest children to goals regarding personal care and eating for children aged 6-11 years. The oldest children preferred goals regarding eating, personal care and computer use. The movement components ‘positioning’, ‘reach’, ‘grasp’, and ‘hold’ were present in most tasks. ‘Manipulating’ was more important for the leading arm-hand, whereas ‘fixating’ was more important for the assisting arm-hand. Conclusion This study gave insight into the preferences regarding

  6. 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.

  7. The Structuring of Neonatal Arm Movements.

    ERIC Educational Resources Information Center

    von Hofsten, Claes; Ronnqvist, Louise

    1993-01-01

    The organization and structuring of spontaneous arm movements of eight neonates were studied quantitatively, with each movement divided into an acceleration phase and a deceleration phase. Found that the movements of the two arms were coupled in all three dimensions of space and had a tendency to follow the body's longitudinal axis. (MDM)

  8. Low back pain associates with altered activity of the cerebral cortex prior to arm movements that require postural adjustment

    PubMed Central

    Jacobs, Jesse V.; Henry, Sharon M.; Nagle, Keith J.

    2009-01-01

    Objective: To determine whether low back pain (LBP) associates with altered postural stabilization and concomitant changes in cerebrocortical motor physiology. Methods: Ten participants with LBP and 10 participants without LBP performed self-initiated, voluntary arm raises. Electromyographic onset latencies of the bilateral internal oblique and erector spinae muscles were analyzed relative to that of the deltoid muscle as measures of anticipatory postural adjustments (APAs). Amplitudes of alpha event-related desynchronization (ERD) and of Bereitschaftspotentials (BP) were calculated from scalp electroencephalography as measures of cerebrocortical motor physiology. Results: The APA was first evident in the trunk muscles contralateral to the arm raise for both groups. Significant alpha ERD was evident bilaterally at the central and parietal electrodes for participants with LBP but only at the electrodes contralateral and midline to the arm raise for those without LBP. The BP amplitudes negatively correlated with APA onset latencies for participants with (but not for those without) LBP. Conclusions: Cerebrocortical activity becomes altered prior to arm movements requiring APAs for individuals with chronic LBP. Significance: These results support a theoretical model that altered central motor neurophysiology associates with LBP, thereby implying that rehabilitation strategies should address these neuromotor impairments. PMID:20071225

  9. Computing Arm Movements with a Monkey Brainet

    PubMed Central

    Ramakrishnan, Arjun; Ifft, Peter J.; Pais-Vieira, Miguel; Woo Byun, Yoon; Zhuang, Katie Z.; Lebedev, Mikhail A.; Nicolelis, Miguel A.L.

    2015-01-01

    Traditionally, brain-machine interfaces (BMIs) extract motor commands from a single brain to control the movements of artificial devices. Here, we introduce a Brainet that utilizes very-large-scale brain activity (VLSBA) from two (B2) or three (B3) nonhuman primates to engage in a common motor behaviour. A B2 generated 2D movements of an avatar arm where each monkey contributed equally to X and Y coordinates; or one monkey fully controlled the X-coordinate and the other controlled the Y-coordinate. A B3 produced arm movements in 3D space, while each monkey generated movements in 2D subspaces (X-Y, Y-Z, or X-Z). With long-term training we observed increased coordination of behavior, increased correlations in neuronal activity between different brains, and modifications to neuronal representation of the motor plan. Overall, performance of the Brainet improved owing to collective monkey behaviour. These results suggest that primate brains can be integrated into a Brainet, which self-adapts to achieve a common motor goal. PMID:26158523

  10. Correlation of primate red nucleus discharge with muscle activity during free-form arm movements.

    PubMed

    Miller, L E; van Kan, P L; Sinkjaer, T; Andersen, T; Harris, G D; Houk, J C

    1993-09-01

    1. We recorded from 239 neurons located in the magnocellular division of the red nucleus of four alert macaque monkeys. At the same time, we recorded electromyographic (EMG) signals from as many as twenty electrodes chronically implanted on muscles of the shoulder, arm, forearm and hand. We recorded EMG signals for periods ranging from several months to a year. 2. The monkeys were trained to perform three free-form food retrieval tasks, each of which activated all of the recorded muscles and most of the neurons. The 'prehension' task required simply that the monkey grasp a piece of food from a fixed point in space. The 'barrier' task required the monkey to reach around a small barrier to obtain the food, and the 'Kluver' task required that food be removed from small holes. During the prehension task, we found approximately equal numbers of neurons that were strongly active while the hand was being moved toward the target (70% of units), and while the food was being grasped (60%). Relatively few units were active as the hand was returned to the mouth (15%). 3. Data files of 1-2 min duration were collected while the monkey performed a single behavioural task. Whenever possible, we recorded files for all three tasks from each neuron. For each file we calculated long time-span analog cross-correlations (+/- 1.28 s) between instantaneous neuronal firing rate and each of the full-wave rectified, low-pass filtered EMG signals. We used the peak correlation and the time of the peak as two summary measures of the functional relation between modulation of neuronal activity and EMG. 4. The magnitude of the strongest correlations was between 0.4 and 0.5 (normalized to a perfect correlation of +/- 1.0). Distal muscles were the most frequently correlated, and extensors were more frequently correlated than flexors. For all monkeys, the lags for well correlated muscles were distributed broadly about a uni-modal value near 0 ms. Eighty five per cent of the correlations larger than

  11. The effects of arm movement on reaction time in patients with latent and active upper trapezius myofascial trigger point

    PubMed Central

    Yassin, Marzieh; Talebian, Saeed; Ebrahimi Takamjani, Ismail; Maroufi, Nader; Ahmadi, Amir; Sarrafzadeh, Javad; Emrani, Anita

    2015-01-01

    Background: Myofascial pain syndrome is a significant source of mechanical pain. The aim of this study was to investigate the effects of arm movement on reaction time in females with latent and active upper trapezius myofascial trigger point. Methods: In this interventional study, a convenience sample of fifteen women with one active MTP, fifteen women with one latent MTP in the upper trapezius, and fifteen normal healthy women were participated. Participants were asked to stand for 10 seconds in an erect standing position. Muscle reaction times were recorded including anterior deltoid (AD), cervical paraspinal (CP) lumbar paraspinal (LP), both of upper trapezius (UT), sternocleidomastoid (SCM) and medial head of gastrocnemius (GcM). Participants were asked to flex their arms in response to a sound stimulus preceded by a warning sound stimulus. Data were analyzed using one-way ANOVA Test. Results: There was significant differences in motor time and reaction time between active and control groups (p< 0.05) except for GcM. There was no significant difference in motor time between active and passive groups except for UT without MTP and SCM (p< 0.05). Also, there were no significant differences in motor times between latent MTP and control groups. Furthermore, there was no significant difference in premotor times between the three groups. Conclusion: The present study shows that patients with active MTP need more time to react to stimulus, but patients with latent MTP are similar to healthy subjects in the reaction time. Patients with active MTP had less compatibility with environmental stimulations, and they responded to a specific stimulation with variability in Surface Electromyography (SEMG). PMID:26913258

  12. The Temporal Structure of Vertical Arm Movements

    PubMed Central

    Gaveau, Jérémie; Papaxanthis, Charalambos

    2011-01-01

    The present study investigates how the CNS deals with the omnipresent force of gravity during arm motor planning. Previous studies have reported direction-dependent kinematic differences in the vertical plane; notably, acceleration duration was greater during a downward than an upward arm movement. Although the analysis of acceleration and deceleration phases has permitted to explore the integration of gravity force, further investigation is necessary to conclude whether feedforward or feedback control processes are at the origin of this incorporation. We considered that a more detailed analysis of the temporal features of vertical arm movements could provide additional information about gravity force integration into the motor planning. Eight subjects performed single joint vertical arm movements (45° rotation around the shoulder joint) in two opposite directions (upwards and downwards) and at three different speeds (slow, natural and fast). We calculated different parameters of hand acceleration profiles: movement duration (MD), duration to peak acceleration (D PA), duration from peak acceleration to peak velocity (D PA-PV), duration from peak velocity to peak deceleration (D PV-PD), duration from peak deceleration to the movement end (D PD-End), acceleration duration (AD), deceleration duration (DD), peak acceleration (PA), peak velocity (PV), and peak deceleration (PD). While movement durations and amplitudes were similar for upward and downward movements, the temporal structure of acceleration profiles differed between the two directions. More specifically, subjects performed upward movements faster than downward movements; these direction-dependent asymmetries appeared early in the movement (i.e., before PA) and lasted until the moment of PD. Additionally, PA and PV were greater for upward than downward movements. Movement speed also changed the temporal structure of acceleration profiles. The effect of speed and direction on the form of acceleration

  13. Activation patterns of mono- and bi-articular arm muscles as a function of force and movement direction of the wrist in humans

    PubMed Central

    van Bolhuis, B M; Gielen, C C A M; van Ingen Schenau, G J

    1998-01-01

    In order to explain the task-dependent activation of muscles, we have investigated the hypothesis that mono- and bi-articular muscles have a different functional role in the control of multijoint movements. According to this hypothesis, bi-articular muscles are activated in a way to control the direction of external force. The mono-articular muscles are thought to be activated to contribute to joint torque mainly during shortening movements.To investigate this hypothesis, surface electromyographic (EMG) recordings were obtained from several mono- and bi-articular arm muscles during voluntary slow movements of the wrist in a horizontal plane against an external force. The direction of force produced at the wrist and the direction of movement of the wrist were varied independently.The results revealed distinct differences between the activation patterns of mono- and bi-articular muscles. The activation of the bi-articular muscles was not affected by movement direction, but appeared to vary exclusively with the direction of force.The mono-articular muscles showed significantly more EMG activity for movements in a specific direction, which equalled the movement direction corresponding to the largest shortening velocity of the muscle. The EMG activity decreased gradually for movements in other directions. This direction-dependent activation appeared to be independent of the direction of the external force. PMID:9490859

  14. Motor Asymmetry Attenuation in Older Adults during Imagined Arm Movements.

    PubMed

    Paizis, Christos; Skoura, Xanthi; Personnier, Pascaline; Papaxanthis, Charalambos

    2014-01-01

    Laterality is an important feature of motor behavior. Several studies have shown that lateralization in right-handed young adults (i.e., right versus left arm superiority) emerges also during imagined actions, that is when an action is internally simulated without any motor output. Such information, however, is lacking for elderly people and it could be valuable to further comprehend the evolution of mental states of action in normal aging. Here, we evaluated the influence of age on motor laterality during mental actions. Twenty-four young (mean age: 24.7 ± 4.4 years) and 24 elderly (mean age: 72.4 ± 3.6 years) participants mentally simulated and actually executed pointing movements with either their dominant-right or non-dominant-left arm in the horizontal plane. We recorded and analyzed the time of actual and mental movements and looked for differences between groups and arms. In addition, electromyographic activity from arm muscle was recorded to quantify any enhancement in muscle activation during mental actions. Our findings indicated that both groups mentally simulated arm movements without activating the muscles of the right or the left arm above the baseline level. This finding suggests that young and, notably, elderly adults are able to generate covert actions without any motor output. We found that manual asymmetries (i.e., faster movements with the right arm) were preserved in young adults for both actual and mental movements. In elderly adults, manual asymmetries were observed for actual but not for mental movements (i.e., equal movement times for both arms). These findings clearly indicate an age-related reduction of motor laterality during mental actions. PMID:24688468

  15. Motor Asymmetry Attenuation in Older Adults during Imagined Arm Movements

    PubMed Central

    Paizis, Christos; Skoura, Xanthi; Personnier, Pascaline; Papaxanthis, Charalambos

    2014-01-01

    Laterality is an important feature of motor behavior. Several studies have shown that lateralization in right-handed young adults (i.e., right versus left arm superiority) emerges also during imagined actions, that is when an action is internally simulated without any motor output. Such information, however, is lacking for elderly people and it could be valuable to further comprehend the evolution of mental states of action in normal aging. Here, we evaluated the influence of age on motor laterality during mental actions. Twenty-four young (mean age: 24.7 ± 4.4 years) and 24 elderly (mean age: 72.4 ± 3.6 years) participants mentally simulated and actually executed pointing movements with either their dominant-right or non-dominant-left arm in the horizontal plane. We recorded and analyzed the time of actual and mental movements and looked for differences between groups and arms. In addition, electromyographic activity from arm muscle was recorded to quantify any enhancement in muscle activation during mental actions. Our findings indicated that both groups mentally simulated arm movements without activating the muscles of the right or the left arm above the baseline level. This finding suggests that young and, notably, elderly adults are able to generate covert actions without any motor output. We found that manual asymmetries (i.e., faster movements with the right arm) were preserved in young adults for both actual and mental movements. In elderly adults, manual asymmetries were observed for actual but not for mental movements (i.e., equal movement times for both arms). These findings clearly indicate an age-related reduction of motor laterality during mental actions. PMID:24688468

  16. Visual gravity influences arm movement planning.

    PubMed

    Sciutti, Alessandra; Demougeot, Laurent; Berret, Bastien; Toma, Simone; Sandini, Giulio; Papaxanthis, Charalambos; Pozzo, Thierry

    2012-06-01

    When submitted to a visuomotor rotation, subjects show rapid adaptation of visually guided arm reaching movements, indicated by a progressive reduction in reaching errors. In this study, we wanted to make a step forward by investigating to what extent this adaptation also implies changes into the motor plan. Up to now, classical visuomotor rotation paradigms have been performed on the horizontal plane, where the reaching motor plan in general requires the same kinematics (i.e., straight path and symmetric velocity profile). To overcome this limitation, we considered vertical and horizontal movement directions requiring specific velocity profiles. This way, a change in the motor plan due to the visuomotor conflict would be measurable in terms of a modification in the velocity profile of the reaching movement. Ten subjects performed horizontal and vertical reaching movements while observing a rotated visual feedback of their motion. We found that adaptation to a visuomotor rotation produces a significant change in the motor plan, i.e., changes to the symmetry of velocity profiles. This suggests that the central nervous system takes into account the visual information to plan a future motion, even if this causes the adoption of nonoptimal motor plans in terms of energy consumption. However, the influence of vision on arm movement planning is not fixed, but rather changes as a function of the visual orientation of the movement. Indeed, a clear influence on motion planning can be observed only when the movement is visually presented as oriented along the vertical direction. Thus vision contributes differently to the planning of arm pointing movements depending on motion orientation in space. PMID:22442569

  17. A Neuro-Fuzzy System for Characterization of Arm Movements

    PubMed Central

    Balbinot, Alexandre; Favieiro, Gabriela

    2013-01-01

    The myoelectric signal reflects the electrical activity of skeletal muscles and contains information about the structure and function of the muscles which make different parts of the body move. Advances in engineering have extended electromyography beyond the traditional diagnostic applications to also include applications in diverse areas such as rehabilitation, movement analysis and myoelectric control of prosthesis. This paper aims to study and develop a system that uses myoelectric signals, acquired by surface electrodes, to characterize certain movements of the human arm. To recognize certain hand-arm segment movements, was developed an algorithm for pattern recognition technique based on neuro-fuzzy, representing the core of this research. This algorithm has as input the preprocessed myoelectric signal, to disclosed specific characteristics of the signal, and as output the performed movement. The average accuracy obtained was 86% to 7 distinct movements in tests of long duration (about three hours). PMID:23429579

  18. Using voluntary motor commands to inhibit involuntary arm movements.

    PubMed

    Ghosh, Arko; Rothwell, John; Haggard, Patrick

    2014-11-01

    A hallmark of voluntary motor control is the ability to stop an ongoing movement. Is voluntary motor inhibition a general neural mechanism that can be focused on any movement, including involuntary movements, or is it mere termination of a positive voluntary motor command? The involuntary arm lift, or 'floating arm trick', is a distinctive long-lasting reflex of the deltoid muscle. We investigated how a voluntary motor network inhibits this form of involuntary motor control. Transcranial magnetic stimulation of the motor cortex during the floating arm trick produced a silent period in the reflexively contracting deltoid muscle, followed by a rebound of muscle activity. This pattern suggests a persistent generator of involuntary motor commands. Instructions to bring the arm down voluntarily reduced activity of deltoid muscle. When this voluntary effort was withdrawn, the involuntary arm lift resumed. Further, voluntary motor inhibition produced a strange illusion of physical resistance to bringing the arm down, as if ongoing involuntarily generated commands were located in a 'sensory blind-spot', inaccessible to conscious perception. Our results suggest that voluntary motor inhibition may be a specific neural function, distinct from absence of positive voluntary motor commands. PMID:25253453

  19. Kinematic decomposition and classification of octopus arm movements

    PubMed Central

    Zelman, Ido; Titon, Myriam; Yekutieli, Yoram; Hanassy, Shlomi; Hochner, Binyamin; Flash, Tamar

    2013-01-01

    The octopus arm is a muscular hydrostat and due to its deformable and highly flexible structure it is capable of a rich repertoire of motor behaviors. Its motor control system uses planning principles and control strategies unique to muscular hydrostats. We previously reconstructed a data set of octopus arm movements from records of natural movements using a sequence of 3D curves describing the virtual backbone of arm configurations. Here we describe a novel representation of octopus arm movements in which a movement is characterized by a pair of surfaces that represent the curvature and torsion values of points along the arm as a function of time. This representation allowed us to explore whether the movements are built up of elementary kinematic units by decomposing each surface into a weighted combination of 2D Gaussian functions. The resulting Gaussian functions can be considered as motion primitives at the kinematic level of octopus arm movements. These can be used to examine underlying principles of movement generation. Here we used combination of such kinematic primitives to decompose different octopus arm movements and characterize several movement prototypes according to their composition. The representation and methodology can be applied to the movement of any organ which can be modeled by means of a continuous 3D curve. PMID:23745113

  20. 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

  1. Evaluating Classifiers to Detect Arm Movement Intention from EEG Signals

    PubMed Central

    Planelles, Daniel; Hortal, Enrique; Costa, Álvaro; Úbeda, Andrés; Iáñez, Eduardo; Azorín, José M.

    2014-01-01

    This paper presents a methodology to detect the intention to make a reaching movement with the arm in healthy subjects before the movement actually starts. This is done by measuring brain activity through electroencephalographic (EEG) signals that are registered by electrodes placed over the scalp. The preparation and performance of an arm movement generate a phenomenon called event-related desynchronization (ERD) in the mu and beta frequency bands. A novel methodology to characterize this cognitive process based on three sums of power spectral frequencies involved in ERD is presented. The main objective of this paper is to set the benchmark for classifiers and to choose the most convenient. The best results are obtained using an SVM classifier with around 72% accuracy. This classifier will be used in further research to generate the control commands to move a robotic exoskeleton that helps people suffering from motor disabilities to perform the movement. The final aim is that this brain-controlled robotic exoskeleton improves the current rehabilitation processes of disabled people. PMID:25268915

  2. Stereotypical reaching movements of the octopus involve both bend propagation and arm elongation.

    PubMed

    Hanassy, S; Botvinnik, A; Flash, T; Hochner, B

    2015-06-01

    force (<0.0016 for an average strain along the arm of around 0.5). This was not observed and moreover such extremely low value does not seem to be physiologically possible. Hence the assumptions made in applying the dynamic model to behaviors such as static arm stiffening that leads to arm extension through bend propagation and the patterns of activation used to simulate such behaviors should be modified to account for movements combining bend propagation and arm elongation. PMID:25970857

  3. Repetitive Arm Movements During Sleep: A Polysomnographic Assessment.

    PubMed

    Torabi-Nami, Mohammad; Mehrabi, Samrad; Derman, Sabri

    2016-07-01

    Sleep-related movement disorders should be differentiated from parasomnias, sleep-associated behavioral disorders, and epilepsy. Polysomnography (PSG) is the gold standard in evaluating such disorders. Periodic leg movement disorder during sleep (PLMS), hypnic jerks, bruxism, rhythmic movement disorder, restless legs syndrome, and nocturnal leg cramps have broadly been discussed in the literature. However, periodic arm movement disorder in sleep (PAMS) is a less-appreciated entity perhaps because arm surface electromyography is not an integral part of the standard polysomnography. Results from our PSG study in a case suspected for PAMS prompted us to herewith discuss this problem. PMID:27563420

  4. Repetitive Arm Movements During Sleep: A Polysomnographic Assessment

    PubMed Central

    Torabi-Nami, Mohammad; Mehrabi, Samrad; Derman, Sabri

    2016-01-01

    Sleep-related movement disorders should be differentiated from parasomnias, sleep-associated behavioral disorders, and epilepsy. Polysomnography (PSG) is the gold standard in evaluating such disorders. Periodic leg movement disorder during sleep (PLMS), hypnic jerks, bruxism, rhythmic movement disorder, restless legs syndrome, and nocturnal leg cramps have broadly been discussed in the literature. However, periodic arm movement disorder in sleep (PAMS) is a less-appreciated entity perhaps because arm surface electromyography is not an integral part of the standard polysomnography. Results from our PSG study in a case suspected for PAMS prompted us to herewith discuss this problem. PMID:27563420

  5. Postural adjustments associated with rapid voluntary arm movements 1. Electromyographic data.

    PubMed Central

    Friedli, W G; Hallett, M; Simon, S R

    1984-01-01

    Normal subjects made bilaterally symmetric rapid elbow flexions or extensions ("focal movement") while free standing or when supported by being strapped to a firm wall behind them (different "postural set"). In some trials a load opposed the movement two thirds of the way into its course. Electromyographic activity in leg and trunk muscles ("associated postural adjustments") demonstrated specific patterns for each type of movement. Activity in these muscles began prior to activity in the arm muscles and demonstrated a distal-to-proximal order of activation. The EMG patterns were characterised by alternating activity in the antagonist pairs similar to the triphasic pattern seen in the arm muscles. When the movement type was changed change of the pattern of the postural muscles occurred over several trials. It is concluded that the associated postural adjustments are pre-programmed motor activity linked to the focal movement, specific for the focal movement including anticipated events and the postural set. PMID:6736995

  6. Optimal control simulations reveal mechanisms by which arm movement improves standing long jump performance.

    PubMed

    Ashby, Blake M; Delp, Scott L

    2006-01-01

    Optimal control simulations of the standing long jump were developed to gain insight into the mechanisms of enhanced performance due to arm motion. The activations that maximize standing long jump distance of a joint torque actuated model were determined for jumps with free and restricted arm movement. The simulated jump distance was 40 cm greater when arm movement was free (2.00 m) than when it was restricted (1.60 m). The majority of the performance improvement in the free arm jump was due to the 15% increase (3.30 vs. 2.86 m/s) in the take-off velocity of the center of gravity. Some of the performance improvement in the free arm jump was attributable to the ability of the jumper to swing the arms backwards during the flight phase to alleviate excessive forward rotation and position the body segments properly for landing. In restricted arm jumps, the excessive forward rotation was avoided by "holding back" during the propulsive phase and reducing the activation levels of the ankle, knee, and hip joint torque actuators. In addition, swinging the arm segments allowed the lower body joint torque actuators to perform 26 J more work in the free arm jump. However, the most significant contribution to developing greater take-off velocity came from the additional 80 J work done by the shoulder actuator in the jump with free arm movement. PMID:15992805

  7. 85 Engaging Movement Activities.

    ERIC Educational Resources Information Center

    Weikart, Phyllis S.; Carlton, Elizabeth B.

    This book presents activities to keep K-6 students moving in a variety of ways as they learn. The movement experiences are planned around key curriculum concepts in movement and music as well as in academic curriculum areas. The experiences develop students' basic timing, language abilities, vocabulary, concentration, planning skills, and…

  8. Single-Trial Neural Correlates of Arm Movement Preparation

    PubMed Central

    Afshar, Afsheen; Santhanam, Gopal; Yu, Byron M.; Ryu, Stephen I.; Sahani, Maneesh; Shenoy, Krishna V.

    2011-01-01

    Summary The process by which neural circuitry in the brain plans and executes arm movements is not well understood. Prevailing data (single-neuron and field potential recordings) do not reveal how individual neurons’ activities are coordinated within the population, and thus inferences about how the neural circuit forms a motor plan have been indirect. Here we frame and test a new ‘initial condition hypothesis’ in which the reaction time (RT) of upcoming movements may be predicted on each trial using neurons’ moment-by-moment firing rates and rates of change of those rates. Using microelectrode array recordings from premotor cortex of monkeys performing delayed-reach movements, we compare such single-trial RT predictions to those of other theories. The initial condition hypothesis model can explain approximately four-fold more RT variance than the best alternative method. Thus, the initial condition hypothesis elucidates a new view of the relationship between single-trial preparatory neural population dynamics and single-trial behavior. PMID:21835350

  9. Prediction in the Vestibular Control of Arm Movements.

    PubMed

    Blouin, Jean; Bresciani, Jean-Pierre; Guillaud, Etienne; Simoneau, Martin

    2015-01-01

    The contribution of vestibular signals to motor control has been evidenced in postural, locomotor, and oculomotor studies. Here, we review studies showing that vestibular information also contributes to the control of arm movements during whole-body motion. The data reviewed suggest that vestibular information is used by the arm motor system to maintain the initial hand position or the planned hand trajectory unaltered during body motion. This requires integration of vestibular and cervical inputs to determine the trunk motion dynamics. These studies further suggest that the vestibular control of arm movement relies on rapid and efficient vestibulomotor transformations that cannot be considered automatic. We also reviewed evidence suggesting that the vestibular afferents can be used by the brain to predict and counteract body-rotation-induced torques (e.g., Coriolis) acting on the arm when reaching for a target while turning the trunk. PMID:26595953

  10. Kinematic feedback control laws for generating natural arm movements.

    PubMed

    Kim, Donghyun; Jang, Cheongjae; Park, Frank C

    2014-03-01

    We propose a stochastic optimal feedback control law for generating natural robot arm motions. Our approach, inspired by the minimum variance principle of Harris and Wolpert (1998 Nature 394 780-4) and the optimal feedback control principles put forth by Todorov and Jordan (2002 Nature Neurosci. 5 1226-35) for explaining human movements, differs in two crucial respects: (i) the endpoint variance is minimized in joint space rather than Cartesian hand space, and (ii) we ignore the dynamics and instead consider only the second-order differential kinematics. The feedback control law generating the motions can be straightforwardly obtained by backward integration of a set of ordinary differential equations; these equations are obtained exactly, without any linear-quadratic approximations. The only parameters to be determined a priori are the variance scale factors, and for both the two-DOF planar arm and the seven-DOF spatial arm, a table of values is constructed based on the given initial and final arm configurations; these values are determined via an optimal fitting procedure, and consistent with existing findings about neuromuscular motor noise levels of human arm muscles. Experiments conducted with a two-link planar arm and a seven-DOF spatial arm verify that the trajectories generated by our feedback control law closely resemble human arm motions, in the sense of producing nearly straight-line hand trajectories, having bell-shaped velocity profiles, and satisfying Fitts Law. PMID:24343165

  11. 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

  12. Accuracy of aimed arm movements in changed gravity.

    PubMed

    Bock, O; Howard, I P; Money, K E; Arnold, K E

    1992-11-01

    We studied the accuracy of aimed arm movements in normal gravity, and during the hypergravity (hyper-G) and microgravity (micro-G) episodes of KC-135 parabolic flights. Subjects pointed at mirror-viewed targets without sight of their arm, and final pointing position was measured by a digitizing pad. Compared with the normal gravity (normal-G) baseline, subjects pointed consistently higher in hyper-G, and still higher in micro-G. Results were not different if subjects viewed targets only during normal-G and pointed at their memorized position under changed gravity (changed-G); this suggests that the "elevator illusion" played a minor role in our study. The observed impairments were attributed to degraded proprioceptive feedback and/or inappropriate motor programs in changed-G. Pointing accuracy improved movement-to-movement but not parabola-to-parabola, indicating that prolonged exposure is needed for sustained adaptation. PMID:1445164

  13. A biologically inspired neural network controller for ballistic arm movements

    PubMed Central

    Bernabucci, Ivan; Conforto, Silvia; Capozza, Marco; Accornero, Neri; Schmid, Maurizio; D'Alessio, Tommaso

    2007-01-01

    Background In humans, the implementation of multijoint tasks of the arm implies a highly complex integration of sensory information, sensorimotor transformations and motor planning. Computational models can be profitably used to better understand the mechanisms sub-serving motor control, thus providing useful perspectives and investigating different control hypotheses. To this purpose, the use of Artificial Neural Networks has been proposed to represent and interpret the movement of upper limb. In this paper, a neural network approach to the modelling of the motor control of a human arm during planar ballistic movements is presented. Methods The developed system is composed of three main computational blocks: 1) a parallel distributed learning scheme that aims at simulating the internal inverse model in the trajectory formation process; 2) a pulse generator, which is responsible for the creation of muscular synergies; and 3) a limb model based on two joints (two degrees of freedom) and six muscle-like actuators, that can accommodate for the biomechanical parameters of the arm. The learning paradigm of the neural controller is based on a pure exploration of the working space with no feedback signal. Kinematics provided by the system have been compared with those obtained in literature from experimental data of humans. Results The model reproduces kinematics of arm movements, with bell-shaped wrist velocity profiles and approximately straight trajectories, and gives rise to the generation of synergies for the execution of movements. The model allows achieving amplitude and direction errors of respectively 0.52 cm and 0.2 radians. Curvature values are similar to those encountered in experimental measures with humans. The neural controller also manages environmental modifications such as the insertion of different force fields acting on the end-effector. Conclusion The proposed system has been shown to properly simulate the development of internal models and to control

  14. Are complex control signals required for human arm movement?

    PubMed

    Gribble, P L; Ostry, D J; Sanguineti, V; Laboissière, R

    1998-03-01

    It has been proposed that the control signals underlying voluntary human arm movement have a "complex" nonmonotonic time-varying form, and a number of empirical findings have been offered in support of this idea. In this paper, we address three such findings using a model of two-joint arm motion based on the lambda version of the equilibrium-point hypothesis. The model includes six one- and two-joint muscles, reflexes, modeled control signals, muscle properties, and limb dynamics. First, we address the claim that "complex" equilibrium trajectories are required to account for nonmonotonic joint impedance patterns observed during multijoint movement. Using constant-rate shifts in the neurally specified equilibrium of the limb and constant cocontraction commands, we obtain patterns of predicted joint stiffness during simulated multijoint movements that match the nonmonotonic patterns reported empirically. We then use the algorithm proposed by Gomi and Kawato to compute a hypothetical equilibrium trajectory from simulated stiffness, viscosity, and limb kinematics. Like that reported by Gomi and Kawato, the resulting trajectory was nonmonotonic, first leading then lagging the position of the limb. Second, we address the claim that high levels of stiffness are required to generate rapid single-joint movements when simple equilibrium shifts are used. We compare empirical measurements of stiffness during rapid single-joint movements with the predicted stiffness of movements generated using constant-rate equilibrium shifts and constant cocontraction commands. Single-joint movements are simulated at a number of speeds, and the procedure used by Bennett to estimate stiffness is followed. We show that when the magnitude of the cocontraction command is scaled in proportion to movement speed, simulated joint stiffness varies with movement speed in a manner comparable with that reported by Bennett. Third, we address the related claim that nonmonotonic equilibrium shifts are

  15. Neuromechanical considerations for incorporating rhythmic arm movement in the rehabilitation of walking

    NASA Astrophysics Data System (ADS)

    Klimstra, Marc D.; Thomas, Evan; Stoloff, Rebecca H.; Ferris, Daniel P.; Zehr, E. Paul

    2009-06-01

    We have extensively used arm cycling to study the neural control of rhythmic movements such as arm swing during walking. Recently rhythmic movement of the arms has also been shown to enhance and shape muscle activity in the legs. However, restricted information is available concerning the conditions necessary to maximally alter lumbar spinal cord excitability. Knowledge on the neuromechanics of a task can assist in the determination of the type, level, and timing of neural signals, yet arm swing during walking and arm cycling have not received a detailed neuromechanical comparison. The purpose of this research was to provide a combined neural and mechanical measurement approach that could be used to assist in the determination of the necessary and sufficient conditions for arm movement to assist in lower limb rehabilitation after stroke and spinal cord injury. Subjects performed three rhythmic arm movement tasks: (1) cycling (cycle); (2) swinging while standing (swing); and (3) swinging while treadmill walking (walk). We hypothesized that any difference in neural control between tasks (i.e., pattern of muscle activity) would reflect changes in the mechanical constraints unique to each task. Three-dimensional kinematics were collected simultaneously with force measurement at the hand and electromyography from the arms and trunk. All data were appropriately segmented to allow a comparison between and across conditions and were normalized and averaged to 100% movement cycle based on shoulder excursion. Separate mathematical principal components analysis of kinematic and neural variables was performed to determine common task features and muscle synergies. The results highlight important neural and mechanical features that distinguish differences between tasks. For example, there are considerable differences in the anatomical positions of the arms during each task, which relate to the moments experienced about the elbow and shoulder. Also, there are differences between

  16. A method for assessing the arm movement performance: probability tube.

    PubMed

    Kostić, Miloš; Popović, Mirjana B; Popović, Dejan B

    2013-12-01

    Quantification of motor performance is an important component of the rehabilitation of humans with sensory-motor disability. We developed a method for assessing arm movement performance of trainees (patients) termed "probability tube" (PT). PT captures the stochastic characteristics of a desired movement when repeated by an expert (therapist). The PT is being generated automatically from data recorded during point-to-point movement executed not more than 15 repetitions by the clinician and/or other non-expert programmer in just a few minutes. We introduce the index, termed probability tube score (PTS), as a single "goodness-of-fit" value allowing quantified analysis of the recovery and effects of the therapy. This index in fact scores the difference between the movement (velocity profile) executed by the trainee and the velocity profile of the desired movement (executed by the expert). We document the goodness of the automatic method with results from studies which included healthy subjects and show the use of the PTS in healthy and post-stroke hemiplegic subjects. PMID:23921787

  17. Movement Structure in Young and Elderly Adults during Goal-Directed Movements of the Left and Right Arm

    ERIC Educational Resources Information Center

    Poston, Brach; Van Gemmert, Arend W. A.; Barduson, Beth; Stelmach, George E.

    2009-01-01

    Elderly adults often exhibit performance deficits during goal-directed movements of the dominant arm compared with young adults. Recent studies involving hemispheric lateralization have provided evidence that the dominant and non-dominant hemisphere-arm systems are specialized for controlling different movement parameters and that hemispheric…

  18. Central resetting of neuromuscular steady states may underlie rhythmical arm movements.

    PubMed

    Ustinova, Ksenia I; Feldman, Anatol G; Levin, Mindy F

    2006-09-01

    Changing the steady-state configuration of the body or its segments may be an important function of central pattern generators for locomotion and other rhythmical movements. Thereby, muscle activation, forces, and movement may emerge following a natural tendency of the neuromuscular system to achieve the current steady-state configuration. To verify that transitions between different steady states occur during rhythmical movements, we asked standing subjects to swing one or both arms synchronously or reciprocally at approximately 0.8 Hz from the shoulder joints. In randomly selected cycles, one arm was transiently arrested by an electromagnetic device. Swinging resumed after some delay and phase resetting. During bilateral swinging, the nonperturbed arm often stopped before resuming swinging at a position that was close to either the extreme forward or the extreme backward arm position observed before the perturbation. Oscillations usually resumed when both arms arrived at similar extreme positions when a synchronous bilateral pattern was initially produced or at the opposite positions if the initial pattern was reciprocal. Results suggest that a central generator controls both arms as a coherent unit by producing transitions between its steady state (equilibrium) positions. By controlling these positions, the system may define the spatial boundaries of movement. At these positions, the system may halt the oscillations, resume them at a new phase (as observed in the present study), or initiate a new motor action. Our findings are relevant to locomotion and suggest that walking may also be generated by transitions between several equilibrium configurations of the body, possibly accomplished by modulation and gating of proprioceptive reflexes. PMID:16707712

  19. Postural adjustments associated with rapid voluntary arm movements. II. Biomechanical analysis.

    PubMed Central

    Friedli, W G; Cohen, L; Hallett, M; Stanhope, S; Simon, S R

    1988-01-01

    Normal subjects performed bilaterally symmetric rapid elbow flexions or extensions ("focal movements") while standing. Specific patterns of electromyographic activity in leg and trunk muscles ("associated postural adjustments") were seen for each type of movement. The biomechanical significance of these postural adjustments was analysed by means of the ground reaction forces and motion of the various body segments. Experimental data were compared with that from a theoretical model of the body consisting of a six segment kinetic chain with rigid links. Distinct patterns of the ground reaction forces with elbow flexion were opposite in direction to those seen with elbow extension. Movements of the various body segments were small and specific for a certain focal movement. Dynamic perturbations arising from the arm movement in an anteroposterior direction were found to be compensated by postural adjustments, whereas vertical perturbations were not compensated. The muscular activity acting about different joints in the different movements was found to correlate with the predictions of activity needed to compensate for net joint reaction moments arising from the focal movement. Motion of the various body segments could be understood as resulting from the interplay of the net reaction moments and the net muscular moments at the different joints. Dynamic postural requirements are accomplished by a precise active compensation initiated before the focal movement. PMID:3346688

  20. The electronic counting arm movement test (eCAM test).

    PubMed

    Bodranghien, Florian; Martin, Claire; Ansay, Caroline; Camut, Stephane; Busegnies, Yves; Manto, Mario

    2015-06-01

    A novel transportable electronic platform aiming to characterize the performance of successive fast vertical visually guided pointing movements toward two fixed targets (eCAM test: electronic counting arm movement test) is described and one validation test is presented. This platform is based on an Arduino(®) micro-controller and a Processing(®) routine. It records both the pointing performance (number of clicks) and the elapsed time between two successive pointing movements. Using this novel platform, we studied the effects of functional electrical stimulation (FES) applied on the dominant upper limb in 15 healthy volunteers (mean age ± SD: 22.3 ± 4.3 years; 5 males/10 females). The following muscles were stimulated: flexor carpi radialis (FCR), extensor carpi radialis (ECR), biceps brachii (BB), and triceps brachii (TB). The intensities of the stimulation were 2 and 3 mA above the sensory threshold (ST). Movement times were lesser when performed against gravity and pointing performance improved with FES. We provide the first demonstration that low-intensity FES impacts on motor performances during successive vertical goal-directed pointing movements under visual guidance. The eCAM test is currently the sole electronic tool to assess quickly and easily the performances of successive vertical pointing movements. Future potential applications include, in particular, the follow-up of the effects of neurorehabilitation of neurological/neurosurgical disorders associated with hand-eye incoordination, the functional evaluation of upper limb prosthesis or orthosis, and the analysis of the effects of FES in central or peripheral nervous system disorders. PMID:25413688

  1. Differential representation of arm movement direction in relation to cortical anatomy and function

    NASA Astrophysics Data System (ADS)

    Ball, Tonio; Schulze-Bonhage, Andreas; Aertsen, Ad; Mehring, Carsten

    2009-02-01

    Information about arm movement direction in neuronal activity of the cerebral cortex can be used for movement control mediated by a brain-machine interface (BMI). Here we provide a topographic analysis of the information related to arm movement direction that can be extracted from single trials of electrocorticographic (ECoG) signals recorded from the human frontal and parietal cortex based on a precise assignment of ECoG recording channels to the subjects' individual cortical anatomy and function. To this aim, each electrode contact was identified on structural MRI scans acquired while the electrodes were implanted and was thus related to the brain anatomy of each patient. Cortical function was assessed by direct cortical electrical stimulation. We show that activity from the primary motor cortex, in particular from the region showing hand and arm motor responses upon electrical stimulation, carries most directional information. The premotor, posterior parietal and lateral prefrontal cortex contributed gradually less, but still significant information. This gradient was observed for decoding from movement-related potentials, and from spectral amplitude modulations in low frequencies and in the high gamma band. Our findings thus demonstrate a close topographic correlation between cortical functional anatomy and direction-related information in humans that might be used for brain-machine interfacing.

  2. 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

  3. A preferred pattern of joint coordination during arm movements with redundant degrees of freedom.

    PubMed

    Dounskaia, Natalia; Wang, Wanyue

    2014-09-01

    Redundancy of degrees of freedom (DOFs) during natural human movements is a central problem of motor control research. This study tests a novel interpretation that during arm movements, the DOF redundancy is used to support a preferred, simplified joint control pattern that consists of rotating either the shoulder or elbow actively and the other (trailing) joint predominantly passively by interaction and gravitational torques. We previously revealed the preference for this control pattern during nonredundant horizontal arm movements. Here, we studied whether this preference persists during movements with redundant DOFs and the redundancy is used to enlarge the range of directions in which this control pattern can be utilized. A free-stroke drawing task was performed that involved production of series of horizontal center-out strokes in randomly selected directions. Two conditions were used, with the arm's joints unconstrained (U) and constrained (C) to the horizontal plane. In both conditions, directional preferences were revealed and the simplified control pattern was used in the preferred and not in nonpreferred directions. The directional preferences were weaker and the range of preferred directions was wider in the U condition, with higher percentage of strokes performed with the simplified control pattern. This advantage was related to the usage of additional DOFs. We discuss that the simplified pattern may represent a feedforward control strategy that reduces the challenge of joint coordination caused by signal-dependent noise during movement execution. The results suggest a possibility that the simplified pattern is used during the majority of natural, seemingly complex arm movements. PMID:24872537

  4. Arm posture score and arm movement during walking: a comprehensive assessment in spastic hemiplegic cerebral palsy.

    PubMed

    Riad, Jacques; Coleman, Scott; Lundh, Dan; Broström, Eva

    2011-01-01

    Patients with hemiplegic cerebral palsy often have noticeably deviant arm posture and decreased arm movement. Here we develop a comprehensive assessment method for the upper extremity during walking. Arm posture score (APS), deviation of shoulder flexion/extension, shoulder abduction/adduction, elbow flexion/extension and wrist flexion/extension were calculated from three-dimensional gait analysis. The APS is the root mean square deviation from normal, similar to Baker's Gait Profile Score (GPS) [1]. The total range of motion (ROM) was defined as the difference between the maximum and minimum position in the gait cycle for each variable. The arm symmetry, arm posture index (API) was calculated by dividing the APS on the hemiplegic side by that on the non-involved side, and the range of motion index (ROMI) by dividing the ROM on the hemiplegic side by that on the non-involved side. Using the APS, two groups were defined. Group 1 had minor deviations, with an APS under 9.0 and a mean of 6.0 (95% CI 5.0-7.0). Group 2 had more pronounced deviations, with an APS over 9.0 and a mean of 13.1 (CI 10.8-15.5) (p=0.000). Total ROM was 60.6 in group 1 and 46.2 in group 2 (p=0.031). API was 0.89 in group 1 and 1.70 in group 2 (p<0.001). ROMI was 1.15 in group 1 and 0.69 in group 2 (p=0.003). APS describes the amount of deviation, ROM provides additional information on movement pattern and the indices the symmetry. These comprehensive objective and dynamic measurements of upper extremity abnormality can be useful in following natural progression, evaluating treatment and making prognoses in several categories of patients. PMID:20971011

  5. Core Muscle Activation in One-Armed and Two-Armed Kettlebell Swing.

    PubMed

    Andersen, Vidar; Fimland, Marius S; Gunnarskog, Aril; Jungård, Georg-Andrè; Slåttland, Roy-Andrè; Vraalsen, Øyvind F; Saeterbakken, Atle H

    2016-05-01

    The aim of the study was to compare the electromyographic activity of rectus abdominis, oblique external, and lower and upper erector spinae at both sides of the truncus in 1-armed and 2-armed kettlebell swing. Sixteen healthy men performed 10 repetitions of both exercises using a 16-kg kettlebell in randomized order. For the upper erector spinae, the activation of the contralateral side during 1-armed swing was 24% greater than that of the ipsilateral side during 1-armed swing (p < 0.001) and 11% greater during 2-armed swing (p = 0.026). Furthermore, the activation in 2-armed swing was 12-16% greater than for the ipsilateral side in 1-armed swing (p < 0.001). For rectus abdominis, however, 42% lower activation of the contralateral side was observed during 1-armed swing compared with ipsilateral sides during 2-armed swing (p = 0.038) and 48% compared with the ipsilateral side during 1-armed swing (p = 0.044). Comparing the different phases of the swing, most differences in the upper erector spinae were found in the lower parts of the movement, whereas for the rectus abdominis, the differences were found during the hip extension. In contrast, similar muscle activity in the lower erector spinae and external oblique between the different conditions was observed (p = 0.055-0.969). In conclusion, performing the kettlebell swing with 1 arm resulted in greater neuromuscular activity for the contralateral side of the upper erector spinae and ipsilateral side of the rectus abdominis, and lower activation of the opposite side of the respective muscles. PMID:26473519

  6. Detecting Elementary Arm Movements by Tracking Upper Limb Joint Angles With MARG Sensors.

    PubMed

    Mazomenos, Evangelos B; Biswas, Dwaipayan; Cranny, Andy; Rajan, Amal; Maharatna, Koushik; Achner, Josy; Klemke, Jasmin; Jobges, Michael; Ortmann, Steffen; Langendorfer, Peter

    2016-07-01

    This paper reports an algorithm for the detection of three elementary upper limb movements, i.e., reach and retrieve, bend the arm at the elbow and rotation of the arm about the long axis. We employ two MARG sensors, attached at the elbow and wrist, from which the kinematic properties (joint angles, position) of the upper arm and forearm are calculated through data fusion using a quaternion-based gradient-descent method and a two-link model of the upper limb. By studying the kinematic patterns of the three movements on a small dataset, we derive discriminative features that are indicative of each movement; these are then used to formulate the proposed detection algorithm. Our novel approach of employing the joint angles and position to discriminate the three fundamental movements was evaluated in a series of experiments with 22 volunteers who participated in the study: 18 healthy subjects and four stroke survivors. In a controlled experiment, each volunteer was instructed to perform each movement a number of times. This was complimented by a seminaturalistic experiment where the volunteers performed the same movements as subtasks of an activity that emulated the preparation of a cup of tea. In the stroke survivors group, the overall detection accuracy for all three movements was 93.75% and 83.00%, for the controlled and seminaturalistic experiment, respectively. The performance was higher in the healthy group where 96.85% of the tasks in the controlled experiment and 89.69% in the seminaturalistic were detected correctly. Finally, the detection ratio remains close ( ±6%) to the average value, for different task durations further attesting to the algorithms robustness. PMID:25966489

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

    PubMed Central

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

    2015-01-01

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

  8. The Averaged EMGs Recorded from the Arm Muscles During Bimanual "Rowing" Movements.

    PubMed

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

    2015-01-01

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

  9. Neural regulation of rhythmic arm and leg movement is conserved across human locomotor tasks.

    PubMed

    Zehr, E Paul; Balter, Jaclyn E; Ferris, Daniel P; Hundza, Sandra R; Loadman, Pamela M; Stoloff, Rebecca H

    2007-07-01

    It has been proposed that different forms of rhythmic human limb movement have a common central neural control ('common core hypothesis'), just as in other animals. We compared the modulation patterns of background EMG and cutaneous reflexes during walking, arm and leg cycling, and arm-assisted recumbent stepping. We hypothesized that patterns of EMG and reflex modulation during cycling and stepping (deduced from mathematical principal components analysis) would be comparable to those during walking because they rely on similar neural substrates. Differences between the tasks were assessed by evoking cutaneous reflexes via stimulation of nerves in the foot and hand in separate trials. The EMG was recorded from flexor and extensor muscles of the arms and legs. Angular positions of the hip, knee and elbow joints were also recorded. Factor analysis revealed that across the three tasks, four principal components explained more than 93% of the variance in the background EMG and middle-latency reflex amplitude. Phase modulation of reflex amplitude was observed in most muscles across all tasks, suggesting activity in similar control networks. Significant correlations between EMG level and reflex amplitude were frequently observed only during static voluntary muscle activation and not during rhythmic movement. Results from a control experiment showed that strong correlation between EMG and reflex amplitudes was observed during discrete, voluntary leg extension but not during walking. There were task-dependent differences in reflex modulation between the three tasks which probably arise owing to specific constraints during each task. Overall, the results show strong correlation across tasks and support common neural patterning as the regulator of arm and leg movement during various rhythmic human movements. PMID:17463036

  10. Strategy of arm movement control is determined by minimization of neural effort for joint coordination.

    PubMed

    Dounskaia, Natalia; Shimansky, Yury

    2016-06-01

    Optimality criteria underlying organization of arm movements are often validated by testing their ability to adequately predict hand trajectories. However, kinematic redundancy of the arm allows production of the same hand trajectory through different joint coordination patterns. We therefore consider movement optimality at the level of joint coordination patterns. A review of studies of multi-joint movement control suggests that a 'trailing' pattern of joint control is consistently observed during which a single ('leading') joint is rotated actively and interaction torque produced by this joint is the primary contributor to the motion of the other ('trailing') joints. A tendency to use the trailing pattern whenever the kinematic redundancy is sufficient and increased utilization of this pattern during skillful movements suggests optimality of the trailing pattern. The goal of this study is to determine the cost function minimization of which predicts the trailing pattern. We show that extensive experimental testing of many known cost functions cannot successfully explain optimality of the trailing pattern. We therefore propose a novel cost function that represents neural effort for joint coordination. That effort is quantified as the cost of neural information processing required for joint coordination. We show that a tendency to reduce this 'neurocomputational' cost predicts the trailing pattern and that the theoretically developed predictions fully agree with the experimental findings on control of multi-joint movements. Implications for future research of the suggested interpretation of the trailing joint control pattern and the theory of joint coordination underlying it are discussed. PMID:26983620

  11. Constraint-Induced Movement Therapy for Rehabilitation of Arm Dysfunction After Stroke in Adults

    PubMed Central

    2011-01-01

    Executive Summary Objective The purpose of this evidence-based analysis is to determine the effectiveness and cost of CIMT for persons with arm dysfunction after a stroke. Clinical Need: Condition and Target Population A stroke is a sudden loss of brain function caused by the interruption of blood flow to the brain (ischemic stroke) or the rupture of blood vessels in the brain (hemorrhagic stroke). A stroke can affect any number of areas including the ability to move, see, remember, speak, reason, and read and write. Stroke is the leading cause of adult neurological disability in Canada; 300,000 people or 1% of the population live with its effects. Up to 85% of persons experiencing a complete stroke have residual arm dysfunction which will interfere with their ability to live independently. Rehabilitation interventions are the cornerstone of care and recovery after a stroke. Constraint-Induced Movement Therapy Constraint-Induced Movement (CIMT) is a behavioural approach to neurorehabilitation based on the principle of ‘learned non-use’. The term is derived from studies in nonhuman primates in which somatosensory deafferentation of a single forelimb was performed and after which the animal then failed to use that limb. This failure to use the limb was deemed ‘learned non-use’. The major components of CIMT include: i) intense repetitive task-oriented training of the impaired limb ii) immobilization of the unimpaired arm, and iii) shaping. With regard to the first component, persons may train the affected arm for several hours a day for up to 10-15 consecutive days. With immobilization, the unaffected arm may be restrained for up to 90% of waking hours. And finally, with shaping, the difficulty of the training tasks is progressively increased as performance improves and encouraging feedback is provided immediately when small gains are achieved. Research Question What is the effectiveness and cost of CIMT compared with physiotherapy and/or occupational therapy

  12. Automating arm movement training following severe stroke: functional exercises with quantitative feedback in a gravity-reduced environment.

    PubMed

    Sanchez, Robert J; Liu, Jiayin; Rao, Sandhya; Shah, Punit; Smith, Robert; Rahman, Tariq; Cramer, Steven C; Bobrow, James E; Reinkensmeyer, David J

    2006-09-01

    An important goal in rehabilitation engineering is to develop technology that allows individuals with severe motor impairment to practice arm movement without continuous supervision from a rehabilitation therapist. This paper describes the development of such a system, called Therapy WREX or ("T-WREX"). The system consists of an orthosis that assists in arm movement across a large workspace, a grip sensor that detects hand grip pressure, and software that simulates functional activities. The arm orthosis is an instrumented, adult-sized version of the Wilmington Robotic Exoskeleton (WREX), which is a five degrees-of-freedom mechanism that passively counterbalances the weight of the arm using elastic bands. After providing a detailed design description of T-WREX, this paper describes two pilot studies of the system's capabilities. The first study demonstrated that individuals with chronic stroke whose arm function is compromised in a normal gravity environment can perform reaching and drawing movements while using T-WREX. The second study demonstrated that exercising the affected arm of five people with chronic stroke with T-WREX over an eight week period improved unassisted movement ability (mean change in Fugl-Meyer score was 5 points +/- 2 SD; mean change in range of motion of reaching was 10%, p < 0.001). These results demonstrate the feasibility of automating upper-extremity rehabilitation therapy for people with severe stroke using passive gravity assistance, a grip sensor, and simple virtual reality software. PMID:17009498

  13. Experimental measure of arm stiffness during single reaching movements with a time-frequency analysis

    PubMed Central

    Pierobon, Alberto; DiZio, Paul; Lackner, James R.

    2013-01-01

    We tested an innovative method to estimate joint stiffness and damping during multijoint unfettered arm movements. The technique employs impulsive perturbations and a time-frequency analysis to estimate the arm's mechanical properties along a reaching trajectory. Each single impulsive perturbation provides a continuous estimation on a single-reach basis, making our method ideal to investigate motor adaptation in the presence of force fields and to study the control of movement in impaired individuals with limited kinematic repeatability. In contrast with previous dynamic stiffness studies, we found that stiffness varies during movement, achieving levels higher than during static postural control. High stiffness was associated with elevated reflexive activity. We observed a decrease in stiffness and a marked reduction in long-latency reflexes around the reaching movement velocity peak. This pattern could partly explain the difference between the high stiffness reported in postural studies and the low stiffness measured in dynamic estimation studies, where perturbations are typically applied near the peak velocity point. PMID:23945781

  14. Monitoring functional arm movement for home-based therapy after stroke.

    PubMed

    Sanchez, R; Reinkensmeyer, D; Shah, P; Liu, J; Rao, S; Smith, R; Cramer, S; Rahman, T; Bobrow, J

    2004-01-01

    The goal of this project is to develop a means for individuals with stroke to practice arm movement therapy at home with remote monitoring. We previously developed a Web-based system for repetitive movement training (Java Therapy). This paper describes a new input device for the system that measures and assists in naturalistic arm movement, as well as software enhancements. The new input device is an instrumented, adult-sized version of Wilmington robotic exoskeleton (WREX), which is a five degrees-of-freedom orthosis that counterbalances the weight of the arm using elastic bands. To test the ability of the new device (Training-WREX or "T-WREX") to measure and assist in functional arm movements, we measured five chronic stroke subjects' movement ability while wearing the orthosis without gravity balance compared to wearing the orthosis with gravity balance. T-WREX's gravity balance function improved a clinical measure of arm movement (Fugl-Meyer Score), range of motion of reaching movements, and accuracy of drawing movements. Coupled with an enhanced version of Java Therapy, T-WREX will thus provide a means to assist functional arm movement training at home, either over the Web in real-time, or stand-alone with periodic communication with a remote site. PMID:17271381

  15. Cortical Activation During Levitation and Tentacular Movements of Corticobasal Syndrome.

    PubMed

    Onofrj, Marco; Bonanni, Laura; Delli Pizzi, Stefano; Caulo, Massimo; Onofrj, Valeria; Thomas, Astrid; Tartaro, Armando; Franciotti, Raffaella

    2015-11-01

    Levitation and tentacular movements (LTM) are considered specific, yet rare (30%), features of Corticobasal Syndrome (CBS), and are erroneously classified as alien hand. Our study focuses on these typical involuntary movements and aims to highlight possible neural correlates.LTM were recognizable during functional magnetic resonance imaging (fMRI) in 4 of 19 CBS patients. FMRI activity was evaluated with an activation recognition program for movements, during LTM, consisting of levitaton and finger writhing, and compared with the absence of movement (rest) and voluntary movements (VM), similar to LTM, of affected and unaffected arm-hand. FMRI acquisition blocks were balanced in order to match LTM blocks with rest and VM conditions. In 1 of the 4 patients, fMRI was acquired only during LTM and with a different equipment.Despite variable intensity and range of involuntary movements, evidenced by videos, fMRI showed, during LTM, a significant (P<0.05-0.001) activation only of the contralateral primary motor cortex (M1). Voluntary movements of the affected and unaffected arm elicited the known network including frontal, supplementary, sensory-motor cortex, and cerebellum. Willed movements of the LTM-affected arm induced higher and wider activation of contralateral M1 compared with the unaffected arm.The isolated activation of M1 suggests that LTM is a cortical disinhibition symptom, not involving a network. Higher activation of M1 during VM confirms that M1 excitability changes occur in CBS. Our study calls, finally, attention to the necessity to separate LTM from other alien hand phenomena. PMID:26559277

  16. Cortical Activation During Levitation and Tentacular Movements of Corticobasal Syndrome

    PubMed Central

    Onofrj, Marco; Bonanni, Laura; Pizzi, Stefano Delli; Caulo, Massimo; Onofrj, Valeria; Thomas, Astrid; Tartaro, Armando; Franciotti, Raffaella

    2015-01-01

    Abstract Levitation and tentacular movements (LTM) are considered specific, yet rare (30%), features of Corticobasal Syndrome (CBS), and are erroneously classified as alien hand. Our study focuses on these typical involuntary movements and aims to highlight possible neural correlates. LTM were recognizable during functional magnetic resonance imaging (fMRI) in 4 of 19 CBS patients. FMRI activity was evaluated with an activation recognition program for movements, during LTM, consisting of levitaton and finger writhing, and compared with the absence of movement (rest) and voluntary movements (VM), similar to LTM, of affected and unaffected arm-hand. FMRI acquisition blocks were balanced in order to match LTM blocks with rest and VM conditions. In 1 of the 4 patients, fMRI was acquired only during LTM and with a different equipment. Despite variable intensity and range of involuntary movements, evidenced by videos, fMRI showed, during LTM, a significant (P<0.05–0.001) activation only of the contralateral primary motor cortex (M1). Voluntary movements of the affected and unaffected arm elicited the known network including frontal, supplementary, sensory-motor cortex, and cerebellum. Willed movements of the LTM-affected arm induced higher and wider activation of contralateral M1 compared with the unaffected arm. The isolated activation of M1 suggests that LTM is a cortical disinhibition symptom, not involving a network. Higher activation of M1 during VM confirms that M1 excitability changes occur in CBS. Our study calls, finally, attention to the necessity to separate LTM from other alien hand phenomena. PMID:26559277

  17. A common neural element receiving rhythmic arm and leg activity as assessed by reflex modulation in arm muscles.

    PubMed

    Sasada, Syusaku; Tazoe, Toshiki; Nakajima, Tsuyoshi; Futatsubashi, Genki; Ohtsuka, Hiroyuki; Suzuki, Shinya; Zehr, E Paul; Komiyama, Tomoyoshi

    2016-04-01

    Neural interactions between regulatory systems for rhythmic arm and leg movements are an intriguing issue in locomotor neuroscience. Amplitudes of early latency cutaneous reflexes (ELCRs) in stationary arm muscles are modulated during rhythmic leg or arm cycling but not during limb positioning or voluntary contraction. This suggests that interneurons mediating ELCRs to arm muscles integrate outputs from neural systems controlling rhythmic limb movements. Alternatively, outputs could be integrated at the motoneuron and/or supraspinal levels. We examined whether a separate effect on the ELCR pathways and cortico-motoneuronal excitability during arm and leg cycling is integrated by neural elements common to the lumbo-sacral and cervical spinal cord. The subjects performed bilateral leg cycling (LEG), contralateral arm cycling (ARM), and simultaneous contralateral arm and bilateral leg cycling (A&L), while ELCRs in the wrist flexor and shoulder flexor muscles were evoked by superficial radial (SR) nerve stimulation. ELCR amplitudes were facilitated by cycling tasks and were larger during A&L than during ARM and LEG. A low stimulus intensity during ARM or LEG generated a larger ELCR during A&L than the sum of ELCRs during ARM and LEG. We confirmed this nonlinear increase in single motor unit firing probability following SR nerve stimulation during A&L. Furthermore, motor-evoked potentials following transcranial magnetic and electrical stimulation did not show nonlinear potentiation during A&L. These findings suggest the existence of a common neural element of the ELCR reflex pathway that is active only during rhythmic arm and leg movement and receives convergent input from contralateral arms and legs. PMID:26961103

  18. A Donders' Like Law for Arm Movements: The Signal not the Noise.

    PubMed

    Ewart, Steven; Hynes, Stephanie M; Darling, Warren G; Capaday, Charles

    2016-01-01

    Experiments were done to determine whether the starting position of the arm influences its final configuration (posture) when pointing to, or grasping, targets located within the common workspace of the arm. Subjects were asked to point to, or grasp, each of six targets from five, or seven, widely spaced starting positions. We found that the variability (standard deviation) of the arm's configuration, measured as the angle of inclination of the plane delimited by the arm and forearm, averaged about 4° for comfortable speed pointing movements and was only slightly higher for fast pointing movements. Comfortable speed reaches to grasp the targets were associated with slightly lower variability (3.5°) in final arm configuration. The average variability of repeated movements to a given target from a single start position (3.5°) was comparable to that of movements from different start positions to the same target (4.2°). A small difference in final arm inclination angle, averaged across all subjects and targets, of 3° was found between two pairs of starting positions. This small and possibly idiosyncratic effect is within the "noise" of final arm orientation variability for repeated movements (i.e., 3.5°). Thus, the variability of final posture is not for the most part due to different start positions, it is inherent to movement per se. Our results reconcile conflicting previous studies and are consistent with past works suggesting that a Donders' like law is indeed largely upheld for unconstrained visually guided arm movements. In summary, considering movements within a typical work space, when the hand is moved voluntarily to a given spatial location the posture of the arm is nearly the same regardless of its starting position. Importantly, variability is inherent to the rule. PMID:27065836

  19. Recognition of elementary arm movements using orientation of a tri-axial accelerometer located near the wrist.

    PubMed

    Biswas, Dwaipayan; Corda, Daniele; Baldus, Giovanni; Cranny, Andy; Maharatna, Koushik; Achner, Josy; Klemke, Jasmin; Jöbges, Michael; Ortmann, Steffen

    2014-09-01

    In this paper we present a method for recognising three fundamental movements of the human arm (reach and retrieve, lift cup to mouth, rotation of the arm) by determining the orientation of a tri-axial accelerometer located near the wrist. Our objective is to detect the occurrence of such movements performed with the impaired arm of a stroke patient during normal daily activities as a means to assess their rehabilitation. The method relies on accurately mapping transitions of predefined, standard orientations of the accelerometer to corresponding elementary arm movements. To evaluate the technique, kinematic data was collected from four healthy subjects and four stroke patients as they performed a number of activities involved in a representative activity of daily living, 'making-a-cup-of-tea'. Our experimental results show that the proposed method can independently recognise all three of the elementary upper limb movements investigated with accuracies in the range 91-99% for healthy subjects and 70-85% for stroke patients. PMID:25119720

  20. Different temporal bases for body and arm movements in volleyball serve reception.

    PubMed

    Benerink, N H; Bootsma, R J; Zaal, F T J M

    2015-10-01

    In many sports, successfully intercepting a ball requires players to move both their body and their arms. Yet, studies of interception typically focus on one or the other. We performed an analysis of the moments of first foot and arm movements of elite-level volleyball players during serve reception. Video footage of five international matches of the Netherlands men's national volleyball team allowed the systematic coding and analysis of 347 different serve reception events. For each event, we identified the time of serve (TS) and time of contact (TC). Ball flight time (from TS to TC) varied between and within types of serve (power jump serves, n = 193, and jumping float serves, n = 154). Correlation analyses revealed that foot movement was initiated with respect to time from TS, while arm movement was initiated with respect to time until TC. These results suggest that whole-body and arm movements rely on different control processes. PMID:25622694

  1. A Donders’ Like Law for Arm Movements: The Signal not the Noise

    PubMed Central

    Ewart, Steven; Hynes, Stephanie M.; Darling, Warren G.; Capaday, Charles

    2016-01-01

    Experiments were done to determine whether the starting position of the arm influences its final configuration (posture) when pointing to, or grasping, targets located within the common workspace of the arm. Subjects were asked to point to, or grasp, each of six targets from five, or seven, widely spaced starting positions. We found that the variability (standard deviation) of the arm’s configuration, measured as the angle of inclination of the plane delimited by the arm and forearm, averaged about 4° for comfortable speed pointing movements and was only slightly higher for fast pointing movements. Comfortable speed reaches to grasp the targets were associated with slightly lower variability (3.5°) in final arm configuration. The average variability of repeated movements to a given target from a single start position (3.5°) was comparable to that of movements from different start positions to the same target (4.2°). A small difference in final arm inclination angle, averaged across all subjects and targets, of 3° was found between two pairs of starting positions. This small and possibly idiosyncratic effect is within the “noise” of final arm orientation variability for repeated movements (i.e., 3.5°). Thus, the variability of final posture is not for the most part due to different start positions, it is inherent to movement per se. Our results reconcile conflicting previous studies and are consistent with past works suggesting that a Donders’ like law is indeed largely upheld for unconstrained visually guided arm movements. In summary, considering movements within a typical work space, when the hand is moved voluntarily to a given spatial location the posture of the arm is nearly the same regardless of its starting position. Importantly, variability is inherent to the rule. PMID:27065836

  2. Multijoint arm stiffness during movements following stroke: implications for robot therapy

    PubMed Central

    Piovesan, D.; Casadio, M.; Mussa-Ivaldi, F. A.; Morasso, P.G

    2015-01-01

    Impaired arm movements in stroke appear as a set of stereotypical kinematic patterns, characterized by abnormal joint coupling, which have a direct consequence on arm mechanics and can be quantified by the net arm stiffness at the hand. The current available measures of arm stiffness during functional tasks have limited clinical use, since they require several repetitions of the same test movement in many directions. Such procedure is difficult to obtain in stroke survivors who have lower fatigue threshold and increased variability compared to unimpaired individuals. The present study proposes a novel, fast quantitative measure of arm stiffness during movements by means of a Time-Frequency technique and the use of a reassigned spectrogram, applied on a trial-by-trial basis with a single perturbation. We tested the technique feasibility during robot mediated therapy, where a robot helped stroke survivors to regain arm mobility by providing assistive forces during a hitting task to 13 targets covering the entire reachable workspace. The endpoint stiffness of the paretic arm was estimated at the end of each hitting movements by suddenly switching of the assistive forces and observing the ensuing recoil movements. In addition, we considered how assistive forces influence stiffness. This method will provide therapists with improved tools to target the treatment to the individual’s specific impairment and to verify the effects of the proposed exercises. PMID:22275576

  3. Brain-machine interface to control a prosthetic arm with monkey ECoGs during periodic movements.

    PubMed

    Morishita, Soichiro; Sato, Keita; Watanabe, Hidenori; Nishimura, Yukio; Isa, Tadashi; Kato, Ryu; Nakamura, Tatsuhiro; Yokoi, Hiroshi

    2014-01-01

    Brain-machine interfaces (BMIs) are promising technologies for rehabilitation of upper limb functions in patients with severe paralysis. We previously developed a BMI prosthetic arm for a monkey implanted with electrocorticography (ECoG) electrodes, and trained it in a reaching task. The stability of the BMI prevented incorrect movements due to misclassification of ECoG patterns. As a trade-off for the stability, however, the latency (the time gap between the monkey's actual motion and the prosthetic arm movement) was about 200 ms. Therefore, in this study, we aimed to improve the response time of the BMI prosthetic arm. We focused on the generation of a trigger event by decoding muscle activity in order to predict integrated electromyograms (iEMGs) from the ECoGs. We verified the achievability of our method by conducting a performance test of the proposed method with actual achieved iEMGs instead of predicted iEMGs. Our results confirmed that the proposed method with predicted iEMGs eliminated the time delay. In addition, we found that motor intention is better reflected by muscle activity estimated from brain activity rather than actual muscle activity. Therefore, we propose that using predicted iEMGs to guide prosthetic arm movement results in minimal delay and excellent performance. PMID:25565947

  4. Nearly automatic motion capture system for tracking octopus arm movements in 3D space.

    PubMed

    Zelman, Ido; Galun, Meirav; Akselrod-Ballin, Ayelet; Yekutieli, Yoram; Hochner, Binyamin; Flash, Tamar

    2009-08-30

    Tracking animal movements in 3D space is an essential part of many biomechanical studies. The most popular technique for human motion capture uses markers placed on the skin which are tracked by a dedicated system. However, this technique may be inadequate for tracking animal movements, especially when it is impossible to attach markers to the animal's body either because of its size or shape or because of the environment in which the animal performs its movements. Attaching markers to an animal's body may also alter its behavior. Here we present a nearly automatic markerless motion capture system that overcomes these problems and successfully tracks octopus arm movements in 3D space. The system is based on three successive tracking and processing stages. The first stage uses a recently presented segmentation algorithm to detect the movement in a pair of video sequences recorded by two calibrated cameras. In the second stage, the results of the first stage are processed to produce 2D skeletal representations of the moving arm. Finally, the 2D skeletons are used to reconstruct the octopus arm movement as a sequence of 3D curves varying in time. Motion tracking, segmentation and reconstruction are especially difficult problems in the case of octopus arm movements because of the deformable, non-rigid structure of the octopus arm and the underwater environment in which it moves. Our successful results suggest that the motion-tracking system presented here may be used for tracking other elongated objects. PMID:19505502

  5. Rhythmic arm movements are less affected than discrete ones after a stroke.

    PubMed

    Leconte, Patricia; Orban de Xivry, Jean-Jacques; Stoquart, Gaëtan; Lejeune, Thierry; Ronsse, Renaud

    2016-06-01

    Recent reports indicate that rhythmic and discrete upper-limb movements are two different motor primitives which recruit, at least partially, distinct neural circuitries. In particular, rhythmic movements recruit a smaller cortical network than discrete movements. The goal of this paper is to compare the levels of disability in performing rhythmic and discrete movements after a stroke. More precisely, we tested the hypothesis that rhythmic movements should be less affected than discrete ones, because they recruit neural circuitries that are less likely to be damaged by the stroke. Eleven stroke patients and eleven age-matched control subjects performed discrete and rhythmic movements using an end-effector robot (REAplan). The rhythmic movement condition was performed with and without visual targets to further decrease cortical recruitment. Movement kinematics was analyzed through specific metrics, capturing the degree of smoothness and harmonicity. We reported three main observations: (1) the movement smoothness of the paretic arm was more severely degraded for discrete movements than rhythmic movements; (2) most of the patients performed rhythmic movements with a lower harmonicity than controls; and (3) visually guided rhythmic movements were more altered than non-visually guided rhythmic movements. These results suggest a hierarchy in the levels of impairment: Discrete movements are more affected than rhythmic ones, which are more affected if they are visually guided. These results are a new illustration that discrete and rhythmic movements are two fundamental primitives in upper-limb movements. Moreover, this hierarchy of impairment opens new post-stroke rehabilitation perspectives. PMID:26749181

  6. Analysis of reaching movements of upper arm in robot assisted exercises. Kinematic assessment of robot assisted upper arm reaching single-joint movements.

    PubMed

    Iuppariello, Luigi; D'Addio, Giovanni; Romano, Maria; Bifulco, Paolo; Lanzillo, Bernardo; Pappone, Nicola; Cesarelli, Mario

    2016-01-01

    Robot-mediated therapy (RMT) has been a very dynamic area of research in recent years. Robotics devices are in fact capable to quantify the performances of a rehabilitation task in treatments of several disorders of the arm and the shoulder of various central and peripheral etiology. Different systems for robot-aided neuro-rehabilitation are available for upper limb rehabilitation but the biomechanical parameters proposed until today, to evaluate the quality of the movement, are related to the specific robot used and to the type of exercise performed. Besides, none study indicated a standardized quantitative evaluation of robot assisted upper arm reaching movements, so the RMT is still far to be considered a standardised tool. In this paper a quantitative kinematic assessment of robot assisted upper arm reaching movements, considering also the effect of gravity on the quality of the movements, is proposed. We studied a group of 10 healthy subjects and results indicate that our advised protocol can be useful for characterising normal pattern in reaching movements. PMID:27459844

  7. [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

  8. Inter-joint coupling strategy during adaptation to novel viscous loads in human arm movement.

    PubMed

    Debicki, D B; Gribble, P L

    2004-08-01

    When arm movements are perturbed by a load, how does the nervous system adjust control signals to reduce error? While it has been shown that the nervous system is capable of compensating for the effects of limb dynamics and external forces, the strategies used to adapt to novel loads are not well understood. We used a robotic exoskeleton [kinesiological instrument for normal and altered reaching movements (KINARM)] to apply novel loads to the arm during single-joint elbow flexions in the horizontal plane (shoulder rotation was allowed). Loads varied in magnitude with the instantaneous velocity of elbow flexion, and were applied to the shoulder in experiment 1 (interaction loads) and the elbow in experiment 2 (direct loads). Initial exposure to both interaction and direct loads resulted in perturbations at both joints, even though the load was applied to only a single joint. Subjects tended to correct for the kinematics of the elbow joint while perturbations at the shoulder persisted. Electromyograms (EMGs) and computed muscle torque showed that subjects modified muscle activity at the elbow to reduce elbow positional deviations. Shoulder muscle activity was also modified; however, these changes were always in the same direction as those at the elbow. Current models of motor control based on inverse-dynamics calculations and force-control, as well as models based on positional control, predict an uncoupling of shoulder and elbow muscle torques for adaptation to these loads. In contrast, subjects in this study adopted a simple strategy of modulating the natural coupling that exists between elbow and shoulder muscle torque during single-joint elbow movements. PMID:15056688

  9. Listing's law for eye, head and arm movements and their synergistic control.

    PubMed

    Straumann, D; Haslwanter, T; Hepp-Reymond, M C; Hepp, K

    1991-01-01

    We have recorded eye, head, and upper arm rotations in five healthy human subjects using the three-dimensional search coil technique. Our measurements show that the coordination of eye and head movements during gaze shifts within +/- 25 deg relative to the forward direction is organized by restricting the rotatory trajectories of the two systems to almost parallel planes. These so-called "Listing planes" for eye-in-space and head-in-space rotations are workspace-oriented, not body-fixed. Eye and head trajectories in their respective planes are closely related in direction and amplitude. For pointing or grasping, the rotatory trajectories of the arm are also restricted to a workspace-oriented Listing plane. During visually guided movements, arm follows gaze, and the nine-dimensional rotatory configuration space for eye-head-arm-synergies (three degrees of freedom for each system) is reduced to a two-dimensional plane in the space of quaternion vectors. PMID:1756791

  10. Modulation of Arm Reaching Movements during Processing of Arm/Hand-Related Action Verbs with and without Emotional Connotation

    PubMed Central

    Spadacenta, Silvia; Gallese, Vittorio; Fragola, Michele; Mirabella, Giovanni

    2014-01-01

    The theory of embodied language states that language comprehension relies on an internal reenactment of the sensorimotor experience associated with the processed word or sentence. Most evidence in support of this hypothesis had been collected using linguistic material without any emotional connotation. For instance, it had been shown that processing of arm-related verbs, but not of those leg-related verbs, affects the planning and execution of reaching movements; however, at present it is unknown whether this effect is further modulated by verbs evoking an emotional experience. Showing such a modulation might shed light on a very debated issue, i.e. the way in which the emotional meaning of a word is processed. To this end, we assessed whether processing arm/hand-related verbs describing actions with negative connotations (e.g. to stab) affects reaching movements differently from arm/hand-related verbs describing actions with neutral connotation (e.g. to comb). We exploited a go/no-go paradigm in which healthy participants were required to perform arm-reaching movements toward a target when verbs expressing emotional hand actions, neutral hand actions or foot actions were shown, and to refrain from moving when no-effector-related verbs were presented. Reaction times and percentages of errors increased when the verb involved the same effector as used to give the response. However, we also found that the size of this interference decreased when the arm/hand-related verbs had a negative emotional connotation. Crucially, we show that such modulation only occurred when the verb semantics had to be retrieved. These results suggest that the comprehension of negatively valenced verbs might require the simultaneous reenactment of the neural circuitry associated with the processing of the emotion evoked by their meaning and of the neural circuitry associated with their motor features. PMID:25093410

  11. Discharge patterns in human motor units during fatiguing arm movements.

    PubMed

    Griffin, L; Garland, S J; Ivanova, T

    1998-11-01

    The purpose of this study was to determine whether short interspike intervals (ISIs of <20 ms) would occur naturally during voluntary movement and would increase in number with fatigue. Thirty-four triceps brachii motor units from nine subjects were assessed during a fatigue task consisting of fifty extension and fifty flexion elbow movements against a constant-load opposing extension. Nineteen motor units were recorded from the beginning of the fatigue task; the number of short ISIs was 7.1 +/- 4.1% of the total number of ISIs in the first one-third of the task (unfatigued state). This value increased to 11.8 +/- 5.9% for the last one-third of the task (fatigued state). Fifteen motor units were recruited during the fatigue task and discharged, with 16.4 +/- 6.0% of short ISIs in the fatigued state. For all motor units, the number of short ISIs was positively correlated (r2 = 0.85) with the recruitment threshold torque. Short ISIs occurred most frequently at movement initiation but also occurred throughout the movement. These results document the presence of short ISIs during voluntary movement and their increase in number during fatigue. PMID:9804570

  12. Goal conceptualization and symmetry of arm movements affect bimanual coordination in individuals after stroke.

    PubMed

    Kantak, Shailesh; McGrath, Robert; Zahedi, Nazaneen

    2016-07-28

    Coordination during goal-directed movements emerges from an interaction of task and individual constraints. It is not known how individuals with unilateral stroke and age-matched controls coordinate their arms when performing symmetric and asymmetric movements to accomplish common task goals compared to independent task goals. Eleven individuals with chronic stroke and ten age-matched controls executed a bimanual task under virtual conditions that allowed systematic manipulation of symmetry and goal conditions. Spatial and temporal bimanual coordination was characterized using the cross-correlation coefficients and time lag between the tangential velocities between the two hands. While task conditions had little effect on coordination of control participants, individuals with stroke were less coordinated in space and time during common-goal bimanual actions employing asymmetric arm movements. Further, patients demonstrated lesser contribution of their paretic arm compared to their non-paretic arm during common-goal conditions. These findings indicate that conceptualization of task goals (common vs. independent) and symmetry of arm movements influence coordination and contribution of the two hands during bimanual tasks in patients with stroke. PMID:27180035

  13. Octopus arm movements under constrained conditions: adaptation, modification and plasticity of motor primitives.

    PubMed

    Richter, Jonas N; Hochner, Binyamin; Kuba, Michael J

    2015-04-01

    The motor control of the eight highly flexible arms of the common octopus (Octopus vulgaris) has been the focus of several recent studies. Our study is the first to manage to introduce a physical constraint to an octopus arm and investigate the adaptability of stereotypical bend propagation in reaching movements and the pseudo-limb articulation during fetching. Subjects (N=6) were placed inside a transparent Perspex box with a hole at the center that allowed the insertion of a single arm. Animals had to reach out through the hole toward a target, to retrieve a food reward and fetch it. All subjects successfully adjusted their movements to the constraint without an adaptation phase. During reaching tasks, the animals showed two movement strategies: stereotypical bend propagation reachings, which were established at the hole of the Perspex box and variant waving-like movements that showed no bend propagations. During fetching movements, no complete pseudo-joint fetching was observed outside the box and subjects pulled their arms through the hole in a pull-in like movement. Our findings show that there is some flexibility in the octopus motor system to adapt to a novel situation. However, at present, it seems that these changes are more an effect of random choices between different alternative motor programs, without showing clear learning effects in the choice between the alternatives. Interestingly, animals were able to adapt the fetching movements to the physical constraint, or as an alternative explanation, they could switch the motor primitive fetching to a different motor primitive 'arm pulling'. PMID:25687436

  14. ARM MOVEMENT AS A CUE FOR THE ESTIMATION OF VISUAL LOCATION.

    PubMed

    Kirsch, Wladimir; Kunde, Wilfried

    2015-08-01

    Two experiments including 24 (M age=29 yr., SD=9; 6 men) and 25 participants (M age=27 yr., SD=9; 8 men), respectively, examined how arm movement extent affects the perception of visual locations. Linear arm movements were performed on a horizontal plane from a start position until an auditory signal occurred. Subsequently, the position of a visual target located along the movement path was judged. The target was judged as further away with an increase in movement extent. The results indicated that motor-related signals are taken into account in visual perception of locations. There were no indications, though, that changes of location perception prompted subsequent changes of action planning, which demonstrates the short-term nature of action-induced plasticity of space perception under the present conditions. PMID:26302194

  15. Decoding Arm and Hand Movements Across Layers of the Macaque Frontal Cortices

    PubMed Central

    Wong, Yan T.; Vigeral, Mariana; Putrino, David; Pfau, David; Merel, Josh; Paninski, Liam; Pesaran, Bijan

    2014-01-01

    A major goal for brain machine interfaces is to allow patients to control prosthetic devices with high degrees of independent movements. Such devices like robotic arms and hands require this high dimensionality of control to restore the full range of actions exhibited in natural movement. Current BMI strategies fall well short of this goal allowing the control of only a few degrees of freedom at a time. In this paper we present work towards the decoding of 27 joint angles from the shoulder, arm and hand as subjects perform reach and grasp movements. We also extend previous work in examining and optimizing the recording depth of electrodes to maximize the movement information that can be extracted from recorded neural signals. PMID:23366250

  16. Gating of tactile information through gamma band during passive arm movement in awake primates

    PubMed Central

    Song, Weiguo; Francis, Joseph T.

    2015-01-01

    To make precise and prompt action in a dynamic environment, the sensorimotor system needs to integrate all related information. The inflow of somatosensory information to the cerebral cortex is regulated and mostly suppressed by movement, which is commonly referred to as sensory gating or gating. Sensory gating plays an important role in preventing redundant information from reaching the cortex, which should be considered when designing somatosensory neuroprosthetics. Gating can occur at several levels within the sensorimotor pathway, while the underlying mechanism is not yet fully understood. The average sensory evoked potential is commonly used to assess sensory information processing, however the assumption of a stereotyped response to each stimulus is still an open question. Event related spectral perturbation (ERSP), which is the power spectrum after time-frequency decomposition on single trial evoked potentials (total power), could overcome this limitation of averaging and provide additional information for understanding the underlying mechanism. To this aim, neural activities in primary somatosensory cortex (S1), primary motor cortex (M1), and ventral posterolateral (VPL) nucleus of thalamus were recorded simultaneously in two areas (S1 and M1 or S1 and VPL) during passive arm movement and rest in awake monkeys. Our results showed that neural activity at different recording areas demonstrated specific and unique response frequency characteristics. Tactile input induced early high frequency responses followed by low frequency oscillations within sensorimotor circuits, and passive movement suppressed these oscillations either in a phase-locked or non-phase-locked manner. Sensory gating by movement was non-phase-locked in M1, and complex in sensory areas. VPL showed gating of non-phase-locked at gamma band and mix of phase-locked and non-phase-locked at low frequency, while S1 showed gating of phase-locked and non-phase-locked at gamma band and an early phase

  17. On the nature of motor planning variables during arm pointing movement: Compositeness and speed dependence.

    PubMed

    Vu, Van Hoan; Isableu, Brice; Berret, Bastien

    2016-07-22

    The purpose of this study was to investigate the nature of the variables and rules underlying the planning of unrestrained 3D arm reaching. To identify whether the brain uses kinematic, dynamic and energetic values in an isolated manner or combines them in a flexible way, we examined the effects of speed variations upon the chosen arm trajectories during free arm movements. Within the optimal control framework, we uncovered which (possibly composite) optimality criterion underlays at best the empirical data. Fifteen participants were asked to perform free-endpoint reaching movements from a specific arm configuration at slow, normal and fast speeds. Experimental results revealed that prominent features of observed motor behaviors were significantly speed-dependent, such as the chosen reach endpoint and the final arm posture. Nevertheless, participants exhibited different arm trajectories and various degrees of speed dependence of their reaching behavior. These inter-individual differences were addressed using a numerical inverse optimal control methodology. Simulation results revealed that a weighted combination of kinematic, energetic and dynamic cost functions was required to account for all the critical features of the participants' behavior. Furthermore, no evidence for the existence of a speed-dependent tuning of these weights was found, thereby suggesting subject-specific but speed-invariant weightings of kinematic, energetic and dynamic variables during the motor planning process of free arm movements. This suggested that the inter-individual difference of arm trajectories and speed dependence was not only due to anthropometric singularities but also to critical differences in the composition of the subjective cost function. PMID:27132233

  18. Motor commands for fast point-to-point arm movements are customized for small changes in inertial load.

    PubMed

    Pinter, Ilona J; Bobbert, Maarten F; van Soest, A J Knoek; Smeets, Jeroen B J

    2011-12-01

    For repeated point-to-point arm movements it is often assumed that motor commands are customized in a trial-to-trial manner, based on previous endpoint error. To test this assumption, we perturbed movement execution without affecting the endpoint error by using a modest manipulation of inertia. Participants made point-to-point elbow flexion and extension movements in the horizontal plane, under the instruction to move as fast as possible from one target area to another. In selected trials the moment of inertia of the lower arm was increased or decreased by 25%. First, we found that an unexpected increase or decrease of inertia did not affect the open loop controlled part of the movement path (and thus endpoint error was not affected). Second, we found that when the increased or decreased inertia was presented repeatedly, after 5-11 trials motor commands were customized: the first 100ms of agonistic muscle activity in the smoothed and rectified electromyographic signal of agonistic muscles was higher for the high inertia compared to the low inertia. We conclude that endpoint error is not the only parameter that is used to evaluate if motor commands lead to movements as planned. PMID:21890379

  19. Minimum energy paths for optimal oscillatory movements of PUMA arm

    SciTech Connect

    Olgac, N.; Zhou, S.

    1988-08-01

    This paper employs a geometric approach in reducing the number of time-consuming iterations necessary for the numerical solution of an optimal energy consumption problem for small amplitude oscillatory motions of robot manipulators. A general objective function in joint space is given for the energy needs in the drives, and specific applications for a commercially available manipulator, Unimation-PUMA 560, are carried out by separating the manipulator motions into two parallel segments: arm and wrist. This process, in general, leads to a highly nonlinear and transcendental optimization problem. The geometric study is presented, and the shortened numerical optimization is carried out. For any given point in the workspace, optimal directions of oscillations and their corresponding energy levels are found. This information is translated into a map of minimum energy levels across the workspace. The map will comprise a section of an intelligent control mechanism of larger scope which is conceived for ultimate use in space and subsea robotic operations. 6 references.

  20. Moving Events in Time: Time-Referent Hand-Arm Movements Influence Perceived Temporal Distance to Past Events

    ERIC Educational Resources Information Center

    Blom, Stephanie S. A. H.; Semin, Gun R.

    2013-01-01

    We examine and find support for the hypothesis that time-referent hand-arm movements influence temporal judgments. In line with the concept of "left is associated with earlier times, and right is associated with later times," we show that performing left (right) hand-arm movements while thinking about a past event increases (decreases) the…

  1. Arm and Hand Movement in Children Suspected of Having Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Braddock, Barbara A.; Hilton, Jane C.

    2016-01-01

    The aim of this study was to describe arm and hand movement in children suspected of having autism spectrum disorder (ASD; age range 29-43 months). A videotaped retrospective review of five children with symptoms of ASD during "Communication Temptation Tasks" was completed at two time points (pre-testing and 6 weeks later). Categories of…

  2. Representation of continuous hand and arm movements in macaque areas M1, F5, and AIP: a comparative decoding study

    NASA Astrophysics Data System (ADS)

    Menz, Veera Katharina; Schaffelhofer, Stefan; Scherberger, Hansjörg

    2015-10-01

    Objective. In the last decade, multiple brain areas have been investigated with respect to their decoding capability of continuous arm or hand movements. So far, these studies have mainly focused on motor or premotor areas like M1 and F5. However, there is accumulating evidence that anterior intraparietal area (AIP) in the parietal cortex also contains information about continuous movement. Approach. In this study, we decoded 27 degrees of freedom representing complete hand and arm kinematics during a delayed grasping task from simultaneously recorded activity in areas M1, F5, and AIP of two macaque monkeys (Macaca mulatta). Main results. We found that all three areas provided decoding performances that lay significantly above chance. In particular, M1 yielded highest decoding accuracy followed by F5 and AIP. Furthermore, we provide support for the notion that AIP does not only code categorical visual features of objects to be grasped, but also contains a substantial amount of temporal kinematic information. Significance. This fact could be utilized in future developments of neural interfaces restoring hand and arm movements.

  3. NETWORK ACTIVATION DURING BIMANUAL MOVEMENTS IN HUMANS

    PubMed Central

    Walsh, RR; Small, SL; Chen, EE; Solodkin, A.

    2008-01-01

    The coordination of movement between the upper limbs is a function highly distributed across the animal kingdom. How the central nervous system generates such bilateral, synchronous movements, and how this differs from the generation of unilateral movements, remains uncertain. Electrophysiologic and functional imaging studies support that the activity of many brain regions during bimanual and unimanual movement are quite similar. Thus, the same brain regions (and indeed the same neurons) respond similarly during unimanual and bimanual movements as measured by electrophysiological responses. How then are different motor behaviors generated? To address this question, we studied unimanual and bimanual movements using fMRI and constructed networks of activation using Structural Equation Modeling (SEM). Our results suggest that (1) the dominant hemisphere appears to initiate activity responsible for bimanual movement; (2) activation during bimanual movement does not reflect the sum of right and left unimanual activation; (3) production of unimanual movement involves a network that is distinct from, and not a mirror of, the network for contralateral unimanual movement; and (4) using SEM, it is possible to obtain robust group networks representative of a population and to identify individual networks which can be used to detect subtle differences both between subjects as well as within a single subject over time. In summary, these results highlight a differential role for the dominant and non-dominant hemispheres during bimanual movements, further elaborating the concept of handedness and dominance. This knowledge increases our understanding of cortical motor physiology in health and after neurological damage. PMID:18718872

  4. Arm Orthosis/Prosthesis Movement Control Based on Surface EMG Signal Extraction.

    PubMed

    Suberbiola, Aaron; Zulueta, Ekaitz; Lopez-Guede, Jose Manuel; Etxeberria-Agiriano, Ismael; Graña, Manuel

    2015-05-01

    This paper shows experimental results on electromyography (EMG)-based system control applied to motorized orthoses. Biceps and triceps EMG signals are captured through two biometrical sensors, which are then filtered and processed by an acquisition system. Finally an output/control signal is produced and sent to the actuators, which will then perform the actual movement, using algorithms based on autoregressive (AR) models and neural networks, among others. The research goal is to predict the desired movement of the lower arm through the analysis of EMG signals, so that the movement can be reproduced by an arm orthosis, powered by two linear actuators. In this experiment, best accuracy has achieved values up to 91%, using a fourth-order AR-model and 100ms block length. PMID:25851029

  5. Patterns of motor activity in the isolated nerve cord of the octopus arm.

    PubMed

    Gutfreund, Yoram; Matzner, Henry; Flash, Tamar; Hochner, Binyamin

    2006-12-01

    The extremely flexible octopus arm provides a unique opportunity for studying movement control in a highly redundant motor system. We describe a novel preparation that allows analysis of the peripheral nervous system of the octopus arm and its interaction with the muscular and mechanosensory elements of the arm's intrinsic muscular system. First we examined the synaptic responses in muscle fibers to identify the motor pathways from the axial nerve cord of the arm to the surrounding musculature. We show that the motor axons project to the muscles via nerve roots originating laterally from the arm nerve cord. The motor field of each nerve is limited to the region where the nerve enters the arm musculature. The same roots also carry afferent mechanosensory information from the intrinsic muscle to the axial nerve cord. Next, we characterized the pattern of activity generated in the dorsal roots by electrically stimulating the axial nerve cord. The evoked activity, although far reaching and long lasting, cannot alone account for the arm extension movements generated by similar electrical stimulation. The mismatch between patterns of activity in the isolated cord and in an intact arm may stem from the involvement of mechanosensory feedback in natural arm extension. PMID:17179381

  6. Intraoperative brachial plexus injury during emergence following movement with arms restrained: a preventable complication?

    PubMed Central

    Chandler, Mark H; DiMatteo, Laura; Hasenboehler, Erik A; Temple, Michael

    2007-01-01

    Background Despite considerable analysis and preventive strategies, brachial plexus injuries remain fairly common in the perioperative setting. These injuries range from brief periods of numbness or discomfort in the immediate postoperative period to, in rare cases, profound, prolonged losses of sensation and function. We present a case of an orthopedic surgery patient who suffered a brachial plexus injury while under anesthesia after trying to sit upright with his arms restrained. Case presentation After the uneventful placement of an intramedullary tibial nail, an 18 year old patient tried to sit upright with his arms restrained while still under the influence of anesthesia. In the immediate postoperative period, the patient complained of a profound loss of sensation in his left arm and an inability to flex his left elbow, suppinate his arm, or abduct and rotate his shoulder. Neurological examination and subsequent studies revealed a C5-6 brachial plexus injury. The patient underwent range of motion physical therapy and, over the next three months, regained the full function and sensation of his left arm. Conclusion Restraining arms during general anesthesia to prevent injury remains a wise practice. However, to avoid injuring the brachial plexus while the arms are restrained, extra caution must be used to prevent unexpected patient movement and to ensure gentle emergence. PMID:18271944

  7. Active Movement Warm-Up Routines

    ERIC Educational Resources Information Center

    Walter, Teri; Quint, Ashleigh; Fischer, Kim; Kiger, Joy

    2011-01-01

    This article presents warm-ups that are designed to physiologically and psychologically prepare students for vigorous physical activity. An active movement warm-up routine is made up of three parts: (1) active warm-up movement exercises, (2) general preparation, and (3) the energy system. These warm-up routines can be used with all grade levels…

  8. Decoding of the spike timing of primary afferents during voluntary arm movements in monkeys

    PubMed Central

    Umeda, Tatsuya; Watanabe, Hidenori; Sato, Masa-aki; Kawato, Mitsuo; Isa, Tadashi; Nishimura, Yukio

    2014-01-01

    Understanding the mechanisms of encoding forelimb kinematics in the activity of peripheral afferents is essential for developing a somatosensory neuroprosthesis. To investigate whether the spike timing of dorsal root ganglion (DRG) neurons could be estimated from the forelimb kinematics of behaving monkeys, we implanted two multi-electrode arrays chronically in the DRGs at the level of the cervical segments in two monkeys. Neuronal activity during voluntary reach-to-grasp movements were recorded simultaneously with the trajectories of hand/arm movements, which were tracked in three-dimensional space using a motion capture system. Sixteen and 13 neurons, including muscle spindles, skin receptors, and tendon organ afferents, were recorded in the two monkeys, respectively. We were able to reconstruct forelimb joint kinematics from the temporal firing pattern of a subset of DRG neurons using sparse linear regression (SLiR) analysis, suggesting that DRG neuronal ensembles encoded information about joint kinematics. Furthermore, we estimated the spike timing of the DRG neuronal ensembles from joint kinematics using an integrate-and-fire model (IF) incorporating the SLiR algorithm. The temporal change of firing frequency of a subpopulation of neurons was reconstructed precisely from forelimb kinematics using the SLiR. The estimated firing pattern of the DRG neuronal ensembles encoded forelimb joint angles and velocities as precisely as the originally recorded neuronal activity. These results suggest that a simple model can be used to generate an accurate estimate of the spike timing of DRG neuronal ensembles from forelimb joint kinematics, and is useful for designing a proprioceptive decoder in a brain machine interface. PMID:24860416

  9. Laboratory Validation of Inertial Body Sensors to Detect Cigarette Smoking Arm Movements

    PubMed Central

    Raiff, Bethany R.; Karataş, Çağdaş; McClure, Erin A.; Pompili, Dario; Walls, Theodore A.

    2014-01-01

    Cigarette smoking remains the leading cause of preventable death in the United States. Traditional in-clinic cessation interventions may fail to intervene and interrupt the rapid progression to relapse that typically occurs following a quit attempt. The ability to detect actual smoking behavior in real-time is a measurement challenge for health behavior research and intervention. The successful detection of real-time smoking through mobile health (mHealth) methodology has substantial implications for developing highly efficacious treatment interventions. The current study was aimed at further developing and testing the ability of inertial sensors to detect cigarette smoking arm movements among smokers. The current study involved four smokers who smoked six cigarettes each in a laboratory-based assessment. Participants were outfitted with four inertial body movement sensors on the arms, which were used to detect smoking events at two levels: the puff level and the cigarette level. Two different algorithms (Support Vector Machines (SVM) and Edge-Detection based learning) were trained to detect the features of arm movement sequences transmitted by the sensors that corresponded with each level. The results showed that performance of the SVM algorithm at the cigarette level exceeded detection at the individual puff level, with low rates of false positive puff detection. The current study is the second in a line of programmatic research demonstrating the proof-of-concept for sensor-based tracking of smoking, based on movements of the arm and wrist. This study demonstrates efficacy in a real-world clinical inpatient setting and is the first to provide a detection rate against direct observation, enabling calculation of true and false positive rates. The study results indicate that the approach performs very well with some participants, whereas some challenges remain with participants who generate more frequent non-smoking movements near the face. Future work may allow for

  10. Motor adaptation to Coriolis force perturbations of reaching movements: endpoint but not trajectory adaptation transfers to the nonexposed arm

    NASA Technical Reports Server (NTRS)

    Dizio, P.; Lackner, J. R.

    1995-01-01

    1. Reaching movements made in a rotating room generate Coriolis forces that are directly proportional to the cross product of the room's angular velocity and the arm's linear velocity. Such Coriolis forces are inertial forces not involving mechanical contact with the arm. 2. We measured the trajectories of arm movements made in darkness to a visual target that was extinguished at the onset of each reach. Prerotation subjects pointed with both the right and left arms in alternating sets of eight movements. During rotation at 10 rpm, the subjects reached only with the right arm. Postrotation, the subjects pointed with the left and right arms, starting with the left, in alternating sets of eight movements. 3. The initial perrotary reaching movements of the right arm were highly deviated both in movement path and endpoint relative to the prerotation reaches of the right arm. With additional movements, subjects rapidly regained straight movement paths and accurate endpoints despite the absence of visual or tactile feedback about reaching accuracy. The initial postrotation reaches of the left arm followed straight paths to the wrong endpoint. The initial postrotation reaches of the right arm had paths with mirror image curvature to the initial perrotation reaches of the right arm but went to the correct endpoint. 4. These observations are inconsistent with current equilibrium point models of movement control. Such theories predict accurate reaches under our experimental conditions. Our observations further show independent implementation of movement and posture, as evidenced by transfer of endpoint adaptation to the nonexposed arm without transfer of path adaptation. Endpoint control may occur at a relatively central stage that represents general constraints such as gravitoinertial force background or egocentric direction relative to both arms, and control of path may occur at a more peripheral stage that represents moments of inertia and muscle dynamics unique to each

  11. A flow visualization study of single-arm sculling movement emulating cephalopod thrust generation

    NASA Astrophysics Data System (ADS)

    Kazakidi, Asimina; Gnanamanickam, Ebenezer P.; Tsakiris, Dimitris P.; Ekaterinaris, John A.

    2014-11-01

    In addition to jet propulsion, octopuses use arm-swimming motion as an effective means of generating bursts of thrust, for hunting, defense, or escape. The individual role of their arms, acting as thrust generators during this motion, is still under investigation, in view of an increasing robotic interest for alternative modes of propulsion, inspired by the octopus. Computational studies have revealed that thrust generation is associated with complex vortical flow patterns in the wake of the moving arm, however further experimental validation is required. Using the hydrogen bubble technique, we studied the flow disturbance around a single octopus-like robotic arm, undergoing two-stroke sculling movements in quiescent fluid. Although simplified, sculling profiles have been found to adequately capture the fundamental kinematics of the octopus arm-swimming behavior. In fact, variation of the sculling parameters alters considerably the generation of forward thrust. Flow visualization revealed the generation of complex vortical structures around both rigid and compliant arms. Increased disturbance was evident near the tip, particularly at the transitional phase between recovery and power strokes. These results are in good qualitative agreement with computational and robotic studies. Work funded by the ESF-GSRT HYDRO-ROB Project PE7(281).

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

    PubMed Central

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

    2015-01-01

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

  13. Contributions of vision and proprioception to arm movement planning in the vertical plane.

    PubMed

    Apker, G A; Karimi, C P; Buneo, C A

    2011-10-10

    The roles of visual and somatosensory information in arm movement planning remain enigmatic. Previous studies have examined these roles by dissociating visual and somatosensory cues about limb position prior to movement onset and examining the resulting effects on movements performed in the horizontal plane. Here we examined the effects of misaligned limb position cues prior to movement onset as reaches were planned and executed along different directions in the vertical plane. Movements were planned with somatosensory and visual feedback aligned at the starting position of the reach or with visual feedback displaced horizontally (Experiment 1) or vertically (Experiment 2). As in the horizontal plane, changes in movement directions induced by misaligned feedback indicated that vision and proprioception were both generally taken into account when planning vertical plane movements. However, we also found evidence that the contributions of vision and proprioception differed across target directions and between directions of displaced visual feedback. These findings suggest that the contributions of vision and proprioception to movement planning in the vertical plane reflect the unique multisensory and biomechanical demands associated with moving against gravity. PMID:21889576

  14. Is the Polar F6 heart rate monitor less accurate during aerobic bench stepping because of arm movements?

    PubMed

    Lloyd, Lisa K; Crixell, Sylvia H; Price, Larry R

    2014-07-01

    Because of the well-documented linear relationship between heart rate and oxygen consumption (VO2), heart rate is commonly used to estimate energy expenditure during exercise. However, previous research suggests that heart rate increases without a concomitant rise in VO2 when arm movements are added to exercise. If so, this could impact the accuracy of heart rate monitors in estimating energy expenditure during combined arm and leg exercise. This study compared the cardiorespiratory responses to a bench step aerobics routine performed with and without arm movements and evaluated whether the accuracy of the Polar F6 heart rate monitor in predicting energy expenditure was impacted by the inclusion of arm movements. Thirty-two women performed the same routine with and without arm movements while stepping up and down off of a 15.24-cm bench at a cadence of 128 b·min-1. Heart rate and VO2 increased, whereas oxygen pulse (VO2·heart rate-1) decreased when arm movements were added (p < 0.001). However, the differences between the energy expenditure estimated by the Polar F6 heart rate monitor and the energy expenditure measured by indirect calorimetry were similar during the same aerobic bench stepping routine performed with and without arms (Δ∼2 kCal·min-1, p ≥ 0.05). Results confirm that arm movements during aerobic bench stepping elicit a disproportionate rise in heart rate relative to V[Combining Dot Above]O2. However, results do not support that these movements increase the prediction error in energy expenditure, as the Polar F6 heart rate monitor over predicted energy expenditure when arm movements were involved and when they were not involved. PMID:24448006

  15. 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

  16. Sonification of Arm Movements in Stroke Rehabilitation – A Novel Approach in Neurologic Music Therapy

    PubMed Central

    Scholz, Daniel S.; Rohde, Sönke; Nikmaram, Nikou; Brückner, Hans-Peter; Großbach, Michael; Rollnik, Jens D.; Altenmüller, Eckart O.

    2016-01-01

    Gross motor impairments are common after stroke, but efficient and motivating therapies for these impairments are scarce. We present an innovative musical sonification therapy, especially designed to retrain patients’ gross motor functions. Sonification should motivate patients and provide additional sensory input informing about relative limb position. Twenty-five stroke patients were included in a clinical pre–post study and took part in the sonification training. The patients’ upper extremity functions, their psychological states, and their arm movement smoothness were assessed pre and post training. Patients were randomly assigned to either of two groups. Both groups received an average of 10 days (M = 9.88; SD = 2.03; 30 min/day) of musical sonification therapy [music group (MG)] or a sham sonification movement training [control group (CG)], respectively. The only difference between the two protocols was that in the CG no sound was played back during training. In the beginning, patients explored the acoustic effects of their arm movements in space. At the end of the training, the patients played simple melodies by coordinated arm movements. The 15 patients in the MG showed significantly reduced joint pain (F = 19.96, p < 0.001) in the Fugl–Meyer assessment after training. They also reported a trend to have improved hand function in the stroke impact scale as compared to the CG. Movement smoothness at day 1, day 5, and the last day of the intervention was compared in MG patients and found to be significantly better after the therapy. Taken together, musical sonification may be a promising therapy for motor impairments after stroke, but further research is required since estimated effect sizes point to moderate treatment outcomes. PMID:27445970

  17. Sonification of Arm Movements in Stroke Rehabilitation - A Novel Approach in Neurologic Music Therapy.

    PubMed

    Scholz, Daniel S; Rohde, Sönke; Nikmaram, Nikou; Brückner, Hans-Peter; Großbach, Michael; Rollnik, Jens D; Altenmüller, Eckart O

    2016-01-01

    Gross motor impairments are common after stroke, but efficient and motivating therapies for these impairments are scarce. We present an innovative musical sonification therapy, especially designed to retrain patients' gross motor functions. Sonification should motivate patients and provide additional sensory input informing about relative limb position. Twenty-five stroke patients were included in a clinical pre-post study and took part in the sonification training. The patients' upper extremity functions, their psychological states, and their arm movement smoothness were assessed pre and post training. Patients were randomly assigned to either of two groups. Both groups received an average of 10 days (M = 9.88; SD = 2.03; 30 min/day) of musical sonification therapy [music group (MG)] or a sham sonification movement training [control group (CG)], respectively. The only difference between the two protocols was that in the CG no sound was played back during training. In the beginning, patients explored the acoustic effects of their arm movements in space. At the end of the training, the patients played simple melodies by coordinated arm movements. The 15 patients in the MG showed significantly reduced joint pain (F = 19.96, p < 0.001) in the Fugl-Meyer assessment after training. They also reported a trend to have improved hand function in the stroke impact scale as compared to the CG. Movement smoothness at day 1, day 5, and the last day of the intervention was compared in MG patients and found to be significantly better after the therapy. Taken together, musical sonification may be a promising therapy for motor impairments after stroke, but further research is required since estimated effect sizes point to moderate treatment outcomes. PMID:27445970

  18. Arm movement maps evoked by cortical magnetic stimulation in a robotic environment

    PubMed Central

    Jones-Lush, Lauren M.; Judkins, Timothy N.; Wittenberg, George F.

    2009-01-01

    Many neurological diseases result in a severe inability to reach for which there is no proven therapy. Promising new interventions to address reaching rehabilitation using robotic training devices are currently under investigation in clinical trials but the neural mechanisms that underlie these interventions are not understood. Transcranial magnetic stimulation (TMS) may be used to probe such mechanisms quickly and non-invasively, by mapping muscle and movement representations in the primary motor cortex (M1). Here we investigate movement maps in healthy young subjects at rest using TMS in the robotic environment, with the goal of determining the range of TMS accessible movements, as a starting point for the study of cortical plasticity in combination with robotic therapy. We systematically stimulated the left motor cortex of 14 normal volunteers while the right hand and forearm rested in the cradle of a two degree-of-freedom planar rehabilitation robot (IMT). Maps were created by applying 10 stimuli at each of 9 locations (3 × 3 cm grid) centered on the M1 movement hotspot for each subject, defined as the stimulation location that elicited robot cradle movements of the greatest distance. TMS-evoked movement kinematics were measured by the robotic encoders and ranged in magnitude from 0–3 cm. Movement maps varied by subject and by location within a subject. However, movements were very consistent within a single stimulation location for a given subject. Movement vectors remained relatively constant (limited to <90 degree section of the planar field) within some subjects across the entire map, while others covered a wider range of directions. This may be due to individual differences in cortical physiology or anatomy, resulting in a practical limit to the areas that are TMS-accessible. This study provides a baseline inventory of possible TMS-evoked arm movements in the robotic reaching trainer, and thus may provide a real-time, non-invasive platform for

  19. Effects of concurrent physical and cognitive demands on arm movement kinematics in a repetitive upper-extremity precision task.

    PubMed

    Srinivasan, Divya; Mathiassen, Svend Erik; Samani, Afshin; Madeleine, Pascal

    2015-08-01

    The effect of concurrent physical and cognitive demands on arm motor control is poorly understood. This exploratory study compared movement kinematics in a repetitive high-precision pipetting task with and without additional concurrent cognitive demands in the form of instructions necessary to locate the correct target tube. Thirty-five healthy female subjects performed a standardized pipetting task, transferring liquid repeatedly from one pick-up tube to different target tubes. In the reference condition, lights indicated the target tube in each movement cycle, while the target tube had to be deciphered from a row and column number on a computer screen in the condition with additional cognitive demands. Kinematics of the dominant arm was assessed using the central tendency and variability of the pipette-tip end-point trajectory and joint kinematics properties of the shoulder and elbow. Movements slowed down (lower velocities and higher area under the movement curves) and trajectory variability increased in the condition with additional cognitive demands, but there were no changes in the kinematics properties such as joint range of motion, times of acceleration and deceleration (as indicated by the time to peak velocity), average angles, or phase relationships between angle and angular velocity of shoulder or elbow movements between the two conditions. Further, there were also no differences in the size or structure of variability of the shoulder and elbow joint angles, suggesting that subjects could maintain the motor repertoire unaltered in the presence of these specific additional cognitive demands. Further studies should address motor control at other levels of concurrent cognitive demands, and with motor tasks that are less automated than the pipetting task used in the present study, so as to gain an increased understanding of the effect of concurrent cognitive demands for other activities of relevance to daily life. PMID:26024788

  20. Movement analysis of upper limb during resistance training using general purpose robot arm "PA10"

    NASA Astrophysics Data System (ADS)

    Morita, Yoshifumi; Yamamoto, Takashi; Suzuki, Takahiro; Hirose, Akinori; Ukai, Hiroyuki; Matsui, Nobuyuki

    2005-12-01

    In this paper we perform movement analysis of an upper limb during resistance training. We selected sanding training, which is one type of resistance training for upper limbs widely performed in occupational therapy. Our final aims in the future are to quantitatively evaluate the therapeutic effect of upper limb motor function during training and to develop a new rehabilitation training support system. For these purposes, first of all we perform movement analysis using a conventional training tool. By measuring upper limb motion during the sanding training we perform feature abstraction. Next we perform movement analysis using the simulated sanding training system. This system is constructed using the general purpose robot arm "PA10". This system enables us to measure the force/torque exerted by subjects and to easily change the load of resistance. The control algorithm is based on impedance control. We found these features of the upper limb motion during the sanding training.

  1. Riemannian geometric approach to human arm dynamics, movement optimization, and invariance

    NASA Astrophysics Data System (ADS)

    Biess, Armin; Flash, Tamar; Liebermann, Dario G.

    2011-03-01

    We present a generally covariant formulation of human arm dynamics and optimization principles in Riemannian configuration space. We extend the one-parameter family of mean-squared-derivative (MSD) cost functionals from Euclidean to Riemannian space, and we show that they are mathematically identical to the corresponding dynamic costs when formulated in a Riemannian space equipped with the kinetic energy metric. In particular, we derive the equivalence of the minimum-jerk and minimum-torque change models in this metric space. Solutions of the one-parameter family of MSD variational problems in Riemannian space are given by (reparametrized) geodesic paths, which correspond to movements with least muscular effort. Finally, movement invariants are derived from symmetries of the Riemannian manifold. We argue that the geometrical structure imposed on the arm’s configuration space may provide insights into the emerging properties of the movements generated by the motor system.

  2. Soft Neurological Signs in Childhood by Measurement of Arm Movements Using Acceleration and Angular Velocity Sensors

    PubMed Central

    Kaneko, Miki; Yamashita, Yushiro; Inomoto, Osamu; Iramina, Keiji

    2015-01-01

    Soft neurological signs (SNS) are evident in the motor performance of children and disappear as the child grows up. Therefore SNS are used as criteria for evaluating age-appropriate development of neurological function. The aim of this study was to quantify SNS during arm movement in childhood. In this study, we focused on pronation and supination, which are arm movements included in the SNS examination. Two hundred and twenty-three typically developing children aged 4–12 years (107 boys, 116 girls) and 18 adults aged 21–26 years (16 males, two females) participated in the experiment. To quantify SNS during pronation and supination, we calculated several evaluation index scores: bimanual symmetry, compliance, postural stability, motor speed and mirror movement. These index scores were evaluated using data obtained from sensors attached to the participants’ hands and elbows. Each score increased as age increased. Results obtained using our system showed developmental changes that were consistent with criteria for SNS. We were able to successfully quantify SNS during pronation and supination. These results indicate that it may be possible to use our system as quantitative criteria for evaluating development of neurological function. PMID:26473867

  3. Soft neurological signs in childhood by measurement of arm movements using acceleration and angular velocity sensors.

    PubMed

    Kaneko, Miki; Yamashita, Yushiro; Inomoto, Osamu; Iramina, Keiji

    2015-01-01

    Soft neurological signs (SNS) are evident in the motor performance of children and disappear as the child grows up. Therefore SNS are used as criteria for evaluating age-appropriate development of neurological function. The aim of this study was to quantify SNS during arm movement in childhood. In this study, we focused on pronation and supination, which are arm movements included in the SNS examination. Two hundred and twenty-three typically developing children aged 4-12 years (107 boys, 116 girls) and 18 adults aged 21-26 years (16 males, two females) participated in the experiment. To quantify SNS during pronation and supination, we calculated several evaluation index scores: bimanual symmetry, compliance, postural stability, motor speed and mirror movement. These index scores were evaluated using data obtained from sensors attached to the participants' hands and elbows. Each score increased as age increased. Results obtained using our system showed developmental changes that were consistent with criteria for SNS. We were able to successfully quantify SNS during pronation and supination. These results indicate that it may be possible to use our system as quantitative criteria for evaluating development of neurological function. PMID:26473867

  4. Therapeutic synergism in the treatment of post-stroke arm paresis utilizing botulinum toxin, robotic therapy, and constraint-induced movement therapy.

    PubMed

    Takebayashi, Takashi; Amano, Satoru; Hanada, Keisuke; Umeji, Atsushi; Takahashi, Kayoko; Koyama, Tetsuo; Domen, Kazuhisa

    2014-11-01

    Botulinum toxin type A (BtxA) injection, constraint-induced movement therapy (CIMT), and robotic therapy (RT) each represent promising approaches to enhance arm motor recovery after stroke. To provide more effective treatment for a 50-year-old man with severe left spastic hemiparesis, we attempted to facilitate CIMT with adaptive approaches to extend the wrist and fingers using RT for 10 consecutive weeks after BtxA injection. This combined treatment resulted in substantial improvements in arm function and the amount of arm use in activities of daily living, and may be effective for stroke patients with severe arm paresis. However, we were unable to sufficiently prove the efficacy of combined treatment based only on a single case. To fully elucidate the efficacy of the combined approach for patients with severe hemiparesis after stroke, future studies of a larger number of patients are needed. PMID:24880058

  5. Movement strategies for maintaining standing balance during arm tracking in people with multiple sclerosis

    PubMed Central

    Chua, Matthew C.; Hyngstrom, Allison S.; Ng, Alexander V.

    2014-01-01

    The purpose of this study was to quantify hip and ankle movement strategies during a standing arm tracking task in people with multiple sclerosis (MS). Full-body kinematics and kinetics were assessed with motion analysis cameras and force plates in nine MS and nine age-matched control subjects. While standing, participants used their dominant hand to track a target moving around a large horizontal or vertical figure eight on a screen in front of them. The target moved at constant speed, or linearly increasing speeds, with a frequency between 0.05 Hz and 0.35 Hz. Hip and ankle moments and angles during tracking were calculated from kinematic and kinetic measurements. Ratios of peak-to-peak (PP) hip/ankle moments (kinetics) and angles (kinematics) were calculated to determine the strategies of the hips and ankles used to maintain balance during arm movements. Center of mass (CoM) root mean square (RMS) acceleration was calculated as a measure of overall balance performance. The MS group produced larger PP hip/ankle moments at all speeds compared with the control group (P < 0.05). The CoM RMS acceleration increased with tracking speed for both groups but was not significantly different between groups. Additionally, the ratios of hip to ankle moments were highly correlated with the Berg Balance Scale during horizontal steady-speed tracking in MS. These results suggest that people with MS increase the use of the hip during standing arm tracking compared with age-matched control subjects. This adapted strategy might allow people with MS to achieve balance performance similar to control subjects, possibly increasing the importance of the hip in maintaining balance during voluntary movements. PMID:24966303

  6. Combined Influence of Visual Scene and Body Tilt on Arm Pointing Movements: Gravity Matters!

    PubMed Central

    Scotto Di Cesare, Cécile; Sarlegna, Fabrice R.; Bourdin, Christophe; Mestre, Daniel R.; Bringoux, Lionel

    2014-01-01

    Performing accurate actions such as goal-directed arm movements requires taking into account visual and body orientation cues to localize the target in space and produce appropriate reaching motor commands. We experimentally tilted the body and/or the visual scene to investigate how visual and body orientation cues are combined for the control of unseen arm movements. Subjects were asked to point toward a visual target using an upward movement during slow body and/or visual scene tilts. When the scene was tilted, final pointing errors varied as a function of the direction of the scene tilt (forward or backward). Actual forward body tilt resulted in systematic target undershoots, suggesting that the brain may have overcompensated for the biomechanical movement facilitation arising from body tilt. Combined body and visual scene tilts also affected final pointing errors according to the orientation of the visual scene. The data were further analysed using either a body-centered or a gravity-centered reference frame to encode visual scene orientation with simple additive models (i.e., ‘combined’ tilts equal to the sum of ‘single’ tilts). We found that the body-centered model could account only for some of the data regarding kinematic parameters and final errors. In contrast, the gravity-centered modeling in which the body and visual scene orientations were referred to vertical could explain all of these data. Therefore, our findings suggest that the brain uses gravity, thanks to its invariant properties, as a reference for the combination of visual and non-visual cues. PMID:24925371

  7. Formation and control of optimal trajectory in human multijoint arm movement. Minimum torque-change model.

    PubMed

    Uno, Y; Kawato, M; Suzuki, R

    1989-01-01

    In this paper, we study trajectory planning and control in voluntary, human arm movements. When a hand is moved to a target, the central nervous system must select one specific trajectory among an infinite number of possible trajectories that lead to the target position. First, we discuss what criterion is adopted for trajectory determination. Several researchers measured the hand trajectories of skilled movements and found common invariant features. For example, when moving the hand between a pair of targets, subjects tended to generate roughly straight hand paths with bell-shaped speed profiles. On the basis of these observations and dynamic optimization theory, we propose a mathematical model which accounts for formation of hand trajectories. This model is formulated by defining an objective function, a measure of performance for any possible movement: square of the rate of change of torque integrated over the entire movement. That is, the objective function CT is defined as follows: (formula; see text) We overcome this difficult by developing an iterative scheme, with which the optimal trajectory and the associated motor command are simultaneously computed. To evaluate our model, human hand trajectories were experimentally measured under various behavioral situations. These results supported the idea that the human hand trajectory is planned and controlled in accordance with the minimum torque-change criterion. PMID:2742921

  8. Effects of bandwidth feedback on the automatization of an arm movement sequence.

    PubMed

    Agethen, Manfred; Krause, Daniel

    2016-02-01

    We examined the effects of a bandwidth feedback manipulation on motor learning. Effects on movement accuracy, as well as on movement consistency, have been addressed in earlier studies. We have additionally investigated the effects on motor automatization. Because providing error feedback is believed to induce attentional control processes, we suppose that a bandwidth method should facilitate motor automatization. Participants (N=48) were assigned to four groups: one control group and three intervention groups. Participants of the intervention groups practiced an arm movement sequence with 760 trials. The BW0-Group practiced with 100% frequency of feedback. For the BW10-Group, feedback was provided when the errors were larger than 10°. The YokedBW10-Group participants were matched to the feedback schedule of research twins from the BW10-Group. All groups performed pre-tests and retention tests with a secondary task paradigm to test for automaticity. The BW10-Group indicated a higher degree of automatization compared with the BW0-Group, which did not exhibit a change in automaticity. The comparison of the YokedBW10-Group, which also exhibited automatization, and the BW10-Group leads to the proposal that reduction of quantitative feedback frequency and additional positive feedback are responsible for the bandwidth effect. Differences in movement accuracy and consistency were not evident. PMID:26605966

  9. Hereditary cerebellar ataxia progressively impairs force adaptation during goal-directed arm movements.

    PubMed

    Maschke, Matthias; Gomez, Christopher M; Ebner, Timothy J; Konczak, Jürgen

    2004-01-01

    We investigated how humans with hereditary cerebellar degeneration [spinocerebellar ataxia (SCA) type 6 and 8, n = 9] and age- and sex-matched healthy controls (n = 9) adapted goal-directed arm movements to an unknown external force field. We tested whether learning could be generalized to untrained regions in the workspace, an aspect central to the idea of an internal model, and if any learning could be retained. After removal of the force field, SCA patients showed little or no learning-related aftereffects indicating that repeated force-field exposure never led to successful force compensation. In contrast, healthy control subjects quickly adapted their movements to the new force field. The difference in force adaptation was significant for movements to targets that required both the shoulder and elbow joint (P < 0.001). Moreover, the generalization of learned movements to targets outside the learned workspace was prevented by the cerebellar degeneration (P < 0.01). Retention of force adaptation was significantly lower in SCA patients (P = 0.003). The severity of ataxia in SCA patients correlated negatively with the extent of learning (r = -0.84, P = 0.004). Our findings imply that progressive loss of cerebellar function gradually impairs force adaptation. The failure to generalize learning suggests that cerebellar degeneration prevents the formation of an internal representation of the limb dynamics. PMID:13679403

  10. Restricted Arm Swing Affects Gait Stability and Increased Walking Speed Alters Trunk Movements in Children with Cerebral Palsy

    PubMed Central

    Delabastita, Tijs; Desloovere, Kaat; Meyns, Pieter

    2016-01-01

    Observational research suggests that in children with cerebral palsy, the altered arm swing is linked to instability during walking. Therefore, the current study investigates whether children with cerebral palsy use their arms more than typically developing children, to enhance gait stability. Evidence also suggests an influence of walking speed on gait stability. Moreover, previous research highlighted a link between walking speed and arm swing. Hence, the experiment aimed to explore differences between typically developing children and children with cerebral palsy taking into account the combined influence of restricting arm swing and increasing walking speed on gait stability. Spatiotemporal gait characteristics, trunk movement parameters and margins of stability were obtained using three dimensional gait analysis to assess gait stability of 26 children with cerebral palsy and 24 typically developing children. Four walking conditions were evaluated: (i) free arm swing and preferred walking speed; (ii) restricted arm swing and preferred walking speed; (iii) free arm swing and high walking speed; and (iv) restricted arm swing and high walking speed. Double support time and trunk acceleration variability increased more when arm swing was restricted in children with bilateral cerebral palsy compared to typically developing children and children with unilateral cerebral palsy. Trunk sway velocity increased more when walking speed was increased in children with unilateral cerebral palsy compared to children with bilateral cerebral palsy and typically developing children and in children with bilateral cerebral palsy compared to typically developing children. Trunk sway velocity increased more when both arm swing was restricted and walking speed was increased in children with bilateral cerebral palsy compared to typically developing children. It is proposed that facilitating arm swing during gait rehabilitation can improve gait stability and decrease trunk movements in

  11. Arm weight support training improves functional motor outcome and movement smoothness after stroke

    PubMed Central

    Bartolo, Michelangelo; De Nunzio, Alessandro Marco; Sebastiano, Fabio; Spicciato, Francesca; Tortola, Paolo; Nilsson, Jan; Pierelli, Francesco

    2014-01-01

    Summary The aim of this study was to compare the effectiveness in acute stroke patients of a rehabilitation program performed with or without an arm weight support device. Twenty-eight acute, first-ever unilateral stroke patients were enrolled in a single-blind, randomized controlled trial. Clinical evaluation included Fugl-Mayer Assessment, Functional Independence Measure and kinematic analysis [maximum and mean hand velocity, maximum range of motion (Max RoM), normalized jerk (NJ)]. Patients received 12 daily 30-minute sessions (6/week) of additional upper limb therapy performed using an arm weight support device (study group) or additional traditional physiotherapy (control group). The patients were evaluated on admission and at the end of the rehabilitation intervention. The two groups were clinically comparable on admission (p>0.05). Both groups showed significant improvements in clinical scale scores and in Max RoM in flexion-extension, while only the study group showed improvements in NJ and in Max RoM in adduction-abduction. Rehabilitation training using an arm weight support device appears to be a useful method to supplement conventional therapy in acute stroke patients, increasing smoothness of movement and motor function. PMID:25014045

  12. A Real-time, 3D Musculoskeletal Model for Dynamic Simulation of Arm Movements

    PubMed Central

    Chadwick, Edward K.; Blana, Dimitra; van den Bogert, Antonie J.; Kirsch, Robert F.

    2010-01-01

    Neuroprostheses can be used to restore movement of the upper limb in individuals with high-level spinal cord injury. Development and evaluation of command and control schemes for such devices typically requires real-time, “patient-in-the-loop” experimentation. A real-time, three-dimensional, musculoskeletal model of the upper limb has been developed for use in a simulation environment to allow such testing to be carried out non-invasively. The model provides real-time feedback of human arm dynamics that can be displayed to the user in a virtual reality environment. The model has a three degree-of-freedom gleno-humeral joint as well as elbow flexion/extension and pronation/supination, and contains 22 muscles of the shoulder and elbow divided into multiple elements. The model is able to run in real time on modest desktop hardware and demonstrates that a large-scale, 3D model can be made to run in real time. This is a prerequisite for a real-time, whole arm model that will form part of a dynamic arm simulator for use in the development, testing and user training of neural prosthesis systems. PMID:19272926

  13. Processing of Hand-Related Verbs Specifically Affects the Planning and Execution of Arm Reaching Movements

    PubMed Central

    Spadacenta, Silvia; Federico, Paolo; Gallese, Vittorio

    2012-01-01

    Even though a growing body of research has shown that the processing of action language affects the planning and execution of motor acts, several aspects of this interaction are still hotly debated. The directionality (i.e. does understanding action-related language induce a facilitation or an interference with the corresponding action?), the time course, and the nature of the interaction (i.e. under what conditions does the phenomenon occur?) are largely unclear. To further explore this topic we exploited a go/no-go paradigm in which healthy participants were required to perform arm reaching movements toward a target when verbs expressing either hand or foot actions were shown, and to refrain from moving when abstract verbs were presented. We found that reaction times (RT) and percentages of errors increased when the verb involved the same effector used to give the response. This interference occurred very early, when the interval between verb presentation and the delivery of the go signal was 50 ms, and could be elicited until this delay was about 600 ms. In addition, RTs were faster when subjects used the right arm than when they used the left arm, suggesting that action–verb understanding is left-lateralized. Furthermore, when the color of the printed verb and not its meaning was the cue for movement execution the differences between RTs and error percentages between verb categories disappeared, unequivocally indicating that the phenomenon occurs only when the semantic content of a verb has to be retrieved. These results are compatible with the theory of embodied language, which hypothesizes that comprehending verbal descriptions of actions relies on an internal simulation of the sensory–motor experience of the action, and provide a new and detailed view of the interplay between action language and motor acts. PMID:22536380

  14. The Relationship between Reduplicated Babble Onset and Laterality Biases in Infant Rhythmic Arm Movements

    PubMed Central

    Iverson, Jana M.; Hall, Amanda J.; Nickel, Lindsay; Wozniak, Robert H.

    2007-01-01

    This study examined changes in rhythmic arm shaking and laterality biases in infants observed longitudinally at three points: just prior to, at, and just following reduplicated babble onset. Infants (ranging in age from 4 to 9 months at babble onset) were videotaped at home as they played with two visually identical audible and silent rattles presented at midline for 1.5 min each. Rate of rattle shaking increased sharply from the pre-babble to babble onset session; but there was no indication that this increase was specific to the right arm. This finding suggests that the link between babble onset and increased rhythmic arm activity may not be the product of language-specific mechanisms, but is rather part of a broader developmental process that is also perceptual and motor. PMID:17196644

  15. Linking motor-related brain potentials and velocity profiles in multi-joint arm reaching movements.

    PubMed

    Amengual, Julià L; Marco-Pallarés, Josep; Grau, Carles; Münte, Thomas F; Rodríguez-Fornells, Antoni

    2014-01-01

    The study of the movement related brain potentials (MRPBs) needs accurate technical approaches to disentangle the specific patterns of bran activity during the preparation and execution of movements. During the last forty years, synchronizing the electromyographic activation (EMG) of the muscle with electrophysiological recordings (EEG) has been commonly ussed for these purposes. However, new clinical approaches in the study of motor diseases and rehabilitation suggest the demand of new paradigms that might go further into the study of the brain activity associated with the kinematics of movements. As a response to this call, we have used a 3-D hand-tracking system with the aim to record continuously the position of an ultrasonic sender attached to the hand during the performance of multi-joint self-paced movements. We synchronized time-series of position and velocity of the sender with the EEG recordings, obtaining specific patterns of brain activity as a function of the fluctuations of the kinematics during natural movement performance. Additionally, the distribution of the brain activity during the preparation and execution phases of movements was similar that reported previously using the EMG, suggesting the validity of our technique. We claim that this paradigm could be usable in patients because of its simplicity and the potential knowledge that can be extracted from clinical protocols. PMID:24808853

  16. Evidence for Composite Cost Functions in Arm Movement Planning: An Inverse Optimal Control Approach

    PubMed Central

    Berret, Bastien; Chiovetto, Enrico; Nori, Francesco; Pozzo, Thierry

    2011-01-01

    An important issue in motor control is understanding the basic principles underlying the accomplishment of natural movements. According to optimal control theory, the problem can be stated in these terms: what cost function do we optimize to coordinate the many more degrees of freedom than necessary to fulfill a specific motor goal? This question has not received a final answer yet, since what is optimized partly depends on the requirements of the task. Many cost functions were proposed in the past, and most of them were found to be in agreement with experimental data. Therefore, the actual principles on which the brain relies to achieve a certain motor behavior are still unclear. Existing results might suggest that movements are not the results of the minimization of single but rather of composite cost functions. In order to better clarify this last point, we consider an innovative experimental paradigm characterized by arm reaching with target redundancy. Within this framework, we make use of an inverse optimal control technique to automatically infer the (combination of) optimality criteria that best fit the experimental data. Results show that the subjects exhibited a consistent behavior during each experimental condition, even though the target point was not prescribed in advance. Inverse and direct optimal control together reveal that the average arm trajectories were best replicated when optimizing the combination of two cost functions, nominally a mix between the absolute work of torques and the integrated squared joint acceleration. Our results thus support the cost combination hypothesis and demonstrate that the recorded movements were closely linked to the combination of two complementary functions related to mechanical energy expenditure and joint-level smoothness. PMID:22022242

  17. Extravehicular activity translation arm (EVATA) study

    NASA Technical Reports Server (NTRS)

    Preiswerk, P. R.; Stammreich, J. R.

    1978-01-01

    The preliminary design of a deployable Extravehicular Activity Translation Arm (EVATA) assembly which will allow an EVA crewman to perform tasks in the vicinity of the External TNK (ET) umbilical doors and to inspect most of the underside of the shuttle spacecraft is reported. The concept chosen for the boom structure was the Astro Extendable Support Structure (ESS) which formed the main structure for the Synthetic Aperture Radar (SAR) Antenna System on the SEASAT A spacecraft. This structure is a deployable triangular truss. A comparison of the EVATA and the SEASAT A ESS is shown. The development of status of the ESS is shown. The satellite configuration, the stowed truss load path, and the envelope deployment sequence for the ESS are also shown.

  18. Do periodic arm movements during sleep exist in healthy subjects? A polysomnographic study

    PubMed Central

    Gabelia, David; Mitterling, Thomas; Högl, Birgit; Wenning, Gregor K.; Frauscher, Birgit

    2014-01-01

    Background Despite several polysomnographic studies on periodic leg movements (PLM) in healthy sleep, data on the prevalence and characteristics of periodic arm movements (PAM) in normal subjects are lacking. We aimed to investigate PAM and their association with PLM during wakefulness and sleep in healthy subjects. Methods Ninety-one participants underwent video-polysomnography according to American Academy of Sleep Medicine 2007 criteria. In addition to standard electromyographic registration, data for both flexor digitorum superficialis muscles were recorded. Results Sixty-two subjects (68.1%) had a PAM index during wakefulness >5/h (median PAM index during wakefulness, 8.8/h; range, 0–77). Seven subjects (7.7%) had a PAM index >5/h during sleep (median PAM index during sleep, 0.7/h; range, 0–47.4). In 14% of cases, PAM during wakefulness were coincident with PLM during wakefulness. During sleep, this coincidence was not evident. The correlation between PAM and PLM was weak to moderate (during wakefulness: Spearman's ρ = 0.576, P < 0.001; during sleep: Spearman's ρ = 0.222, P = 0.036). Conclusion In healthy subjects, PAM occur predominantly during wakefulness with no apparent true periodicity. In contrast to classical PLM, some PAM may not present a true periodic phenomenon, but rather random voluntary movements meeting the wide range of periodicity criteria for PLM. PMID:25037838

  19. The size and structure of arm movement variability decreased with work pace in a standardised repetitive precision task.

    PubMed

    Srinivasan, Divya; Samani, Afshin; Mathiassen, Svend Erik; Madeleine, Pascal

    2015-01-01

    Increased movement variability has been suggested to reduce the risk of developing musculoskeletal disorders caused by repetitive work. This study investigated the effects of work pace on arm movement variability in a standardised repetitive pipetting task performed by 35 healthy women. During pipetting at slow and fast paces differing by 15%, movements of arm, hand and pipette were tracked in 3D, and used to derive shoulder and elbow joint angles. The size of cycle-to-cycle motor variability was quantified using standard deviations of several kinematics properties, while the structure of variability was quantified using indices of sample entropy and recurrence quantification analysis. When pace increased, both the size and structure of motor variability in the shoulder and elbow decreased. These results suggest that motor variability drops when repetitive movements are performed at increased paces, which may in the long run lead to undesirable outcomes such as muscle fatigue or overuse. PMID:25216404

  20. Movement.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

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

  1. Are occupational repetitive movements of the upper arm associated with rotator cuff calcific tendinopathies?

    PubMed

    Sansone, Valerio C; Meroni, Roberto; Boria, Paola; Pisani, Salvatore; Maiorano, Emanuele

    2015-02-01

    Calcifying tendinopathy (CT) of the shoulder is a common painful disorder, although the etiology and pathogenesis remain largely unknown. Recent theories about the role of excessive mechanical load in the genesis of CT have been proposed. Driven by the interest for these new theories, we investigated the hypothesis of a relationship between work-related repetitive movements of the upper arm, considered a potential cause of shoulder overload, and the presence of shoulder CT. A secondary aim was to obtain data on CT prevalence in a female sample from the working-age general population, as little data currently exist. 199 supermarket cashiers and 304 female volunteers recruited from the general population underwent a high-resolution ultrasonography of the rotator cuffs of both shoulders, and the presence of tendinopathies, with or without calcification, was recorded. The prevalence of calcific tendinopathy was 22.6 % in the cashiers group and 24.4 % in the control group. There were no statistically significant differences in the prevalence of calcifications between the two groups (p = 0.585), either for the dominant shoulder [OR = 0.841 (95 % CI 0.534-1.326)] or for the non-dominant shoulder [OR = 0.988 (95 % CI 0.582-1.326)]. We observed bilateral calcifications in 8.5 % of cashiers, and 9.6 % of controls, and an increase in prevalence of CT with age in both groups. Work-related repetitive movements of the upper arm did not induce a higher prevalence of shoulder CT compared with the female sample from the general population. If CT etiopathogenesis is related to mechanical load, CT onset may be influenced not only by loading history, but also by individual factors. Level of evidence Prognosis study, Level II. PMID:25000922

  2. Neural control of rhythmic, cyclical human arm movement: task dependency, nerve specificity and phase modulation of cutaneous reflexes

    PubMed Central

    Zehr, E Paul; Kido, Aiko

    2001-01-01

    The organization and pattern of cutaneous reflex modulation during rhythmic cyclical movements of the human upper limbs has received much less attention than that afforded the lower limb. Our working hypothesis is that control mechanisms underlying the modulation of cutaneous reflex amplitude during rhythmic arm movement are similar to those that control reflex modulation in the leg. Thus, we hypothesized that cutaneous reflexes would show task dependency and nerve specificity in the upper limb during rhythmic cyclical arm movement as has been demonstrated in the human lower limb. EMG was recorded from 10 muscles crossing the human shoulder, elbow and wrist joints while bilateral whole arm rhythmic cyclical movements were performed on a custom-made, hydraulic apparatus. Cutaneous reflexes were evoked with trains (5× 1.0 ms pulses at 300 Hz) of electrical stimulation delivered at non-noxious intensities (∼2× threshold for radiating parasthesia) to the superficial radial, median and ulnar nerves innervating the hand. Cutaneous reflexes were typically modulated with the movement cycle (i.e. phase dependency was observed). There was evidence for nerve specificity of cutaneous reflexes during rhythmic movement of the upper limbs. Task-dependent modulation was also seen as cutaneous reflexes were of larger amplitude or inhibitory (reflex reversal) during arm cycling as compared to static contraction. While there are some differences in the patterns of cutaneous reflex modulation seen between the arms and legs, it is concluded that cutaneous reflexes are modulated similarly in the upper and lower limbs implicating similar motor control mechanisms. PMID:11744775

  3. Analysis of scapular kinematics during active and passive arm elevation

    PubMed Central

    Kai, Yoshihiro; Gotoh, Masafumi; Takei, Kazuto; Madokoro, Kazuya; Imura, Takeshi; Murata, Shin; Morihara, Toru; Shiba, Naoto

    2016-01-01

    [Purpose] Early postoperative passive motion exercise after arthroscopic rotator cuff repair remains controversial. To better understand this issue, this study was aimed at evaluating scapular kinematics and muscle activities during passive arm elevation in healthy subjects. [Subjects and Methods] The dominant shoulders of 27 healthy subjects were examined. Electromagnetic sensors attached to the scapula, thorax, and humerus were used to determine three-dimensional scapular kinematics during active arm elevation with or without external loads and passive arm elevation. Simultaneously, the activities of seven shoulder muscles were recorded with surface and intramuscular fine-wire electrodes. [Results] Compared with active arm elevation, passive elevation between 30° and 100° significantly decreased the scapular upward rotation and increased the glenohumeral elevation angle. However, no significant differences in scapular posterior tilt and external rotation were observed between active and passive arm elevation, and scapular plane kinematics were not affected by muscle activity. [Conclusion] Unlike active motion with or without an external load, passive arm elevation significantly decreased the scapular upward rotation and significantly increased the mid-range glenohumeral elevation. These data, which suggest that passive arm elevation should be avoided during the early postoperative period, may expand the understanding of rehabilitation after arthroscopic rotator cuff repair. PMID:27390438

  4. Analysis of scapular kinematics during active and passive arm elevation.

    PubMed

    Kai, Yoshihiro; Gotoh, Masafumi; Takei, Kazuto; Madokoro, Kazuya; Imura, Takeshi; Murata, Shin; Morihara, Toru; Shiba, Naoto

    2016-06-01

    [Purpose] Early postoperative passive motion exercise after arthroscopic rotator cuff repair remains controversial. To better understand this issue, this study was aimed at evaluating scapular kinematics and muscle activities during passive arm elevation in healthy subjects. [Subjects and Methods] The dominant shoulders of 27 healthy subjects were examined. Electromagnetic sensors attached to the scapula, thorax, and humerus were used to determine three-dimensional scapular kinematics during active arm elevation with or without external loads and passive arm elevation. Simultaneously, the activities of seven shoulder muscles were recorded with surface and intramuscular fine-wire electrodes. [Results] Compared with active arm elevation, passive elevation between 30° and 100° significantly decreased the scapular upward rotation and increased the glenohumeral elevation angle. However, no significant differences in scapular posterior tilt and external rotation were observed between active and passive arm elevation, and scapular plane kinematics were not affected by muscle activity. [Conclusion] Unlike active motion with or without an external load, passive arm elevation significantly decreased the scapular upward rotation and significantly increased the mid-range glenohumeral elevation. These data, which suggest that passive arm elevation should be avoided during the early postoperative period, may expand the understanding of rehabilitation after arthroscopic rotator cuff repair. PMID:27390438

  5. The inactivation principle: mathematical solutions minimizing the absolute work and biological implications for the planning of arm movements.

    PubMed

    Berret, Bastien; Darlot, Christian; Jean, Frédéric; Pozzo, Thierry; Papaxanthis, Charalambos; Gauthier, Jean Paul

    2008-10-01

    An important question in the literature focusing on motor control is to determine which laws drive biological limb movements. This question has prompted numerous investigations analyzing arm movements in both humans and monkeys. Many theories assume that among all possible movements the one actually performed satisfies an optimality criterion. In the framework of optimal control theory, a first approach is to choose a cost function and test whether the proposed model fits with experimental data. A second approach (generally considered as the more difficult) is to infer the cost function from behavioral data. The cost proposed here includes a term called the absolute work of forces, reflecting the mechanical energy expenditure. Contrary to most investigations studying optimality principles of arm movements, this model has the particularity of using a cost function that is not smooth. First, a mathematical theory related to both direct and inverse optimal control approaches is presented. The first theoretical result is the Inactivation Principle, according to which minimizing a term similar to the absolute work implies simultaneous inactivation of agonistic and antagonistic muscles acting on a single joint, near the time of peak velocity. The second theoretical result is that, conversely, the presence of non-smoothness in the cost function is a necessary condition for the existence of such inactivation. Second, during an experimental study, participants were asked to perform fast vertical arm movements with one, two, and three degrees of freedom. Observed trajectories, velocity profiles, and final postures were accurately simulated by the model. In accordance, electromyographic signals showed brief simultaneous inactivation of opposing muscles during movements. Thus, assuming that human movements are optimal with respect to a certain integral cost, the minimization of an absolute-work-like cost is supported by experimental observations. Such types of optimality

  6. Differentiated ratings of perceived exertion and physiological responses during aerobic dance steps by impact/type of arm movement.

    PubMed

    Schaeffer-Gerschutz, S A; Darby, L A; Browder, K D

    2000-04-01

    Overall ratings of perceived exertion, i.e., undifferentiated RPE, are often used as indicators of exercise intensity during walking, jogging, and cycling; however, conflicting results concerning RPE during aerobic dance exercise have been reported, and the use of differentiated RPE, i.e., local RPE and central RPE, has not been investigated. The purposes of this study were to assess local, central, and over-all RPE, and physiological responses [heart rate (HR); % HRmax; absolute and relative VO2;% VO2 max, ventilation (VE), ventilatory equivalent (VE.VO2(-1); and oxygen pulse] during aerobic dance exercise varied by Arm Movement (Static Arm vs Dynamic Arm) and Impact (High vs Low). Trained women (N = 25; max VO2 = 50.4 +/- 7.5 ml.kg-1.min.-1) completed four aerobic dance steps. No RPE were significantly correlated with heart rate or VO2; however, for all steps all RPE were significantly (r = .40-.62) correlated with VE.VO2(-1) or VE. No interactions were present for RPE or physiological variables, and main effects were noted for Impact and Arm Movement. All RPE were greater for High Impact and for Static Arm Movement. Because VE and VE.VO2(-1) were correlated with Overall RPE for all steps, this may suggest that participants "attended to" perceived changes in respiratory phenomena during aerobic dance exercise. It appears that during combined arm-and-leg aerobic dance exercise the use of Overall RPE is sufficient to assess perceptual sensations associated with the intensity of the exercise. Changes in Overall RPE were proportionate to objective measures of exercise intensity, i.e., HR and VO2; however, it is recommended that both HR and Overall RPE be used to assess fully a participant's objective and subjective responses during aerobic dance exercise. PMID:10833740

  7. Active inference, eye movements and oculomotor delays.

    PubMed

    Perrinet, Laurent U; Adams, Rick A; Friston, Karl J

    2014-12-01

    This paper considers the problem of sensorimotor delays in the optimal control of (smooth) eye movements under uncertainty. Specifically, we consider delays in the visuo-oculomotor loop and their implications for active inference. Active inference uses a generalisation of Kalman filtering to provide Bayes optimal estimates of hidden states and action in generalised coordinates of motion. Representing hidden states in generalised coordinates provides a simple way of compensating for both sensory and oculomotor delays. The efficacy of this scheme is illustrated using neuronal simulations of pursuit initiation responses, with and without compensation. We then consider an extension of the generative model to simulate smooth pursuit eye movements-in which the visuo-oculomotor system believes both the target and its centre of gaze are attracted to a (hidden) point moving in the visual field. Finally, the generative model is equipped with a hierarchical structure, so that it can recognise and remember unseen (occluded) trajectories and emit anticipatory responses. These simulations speak to a straightforward and neurobiologically plausible solution to the generic problem of integrating information from different sources with different temporal delays and the particular difficulties encountered when a system-like the oculomotor system-tries to control its environment with delayed signals. PMID:25128318

  8. Robust adaptive control modeling of human arm movements subject to altered gravity and mechanical loads

    NASA Astrophysics Data System (ADS)

    Tryfonidis, Michail

    It has been observed that during orbital spaceflight the absence of gravitation related sensory inputs causes incongruence between the expected and the actual sensory feedback resulting from voluntary movements. This incongruence results in a reinterpretation or neglect of gravity-induced sensory input signals. Over time, new internal models develop, gradually compensating for the loss of spatial reference. The study of adaptation of goal-directed movements is the main focus of this thesis. The hypothesis is that during the adaptive learning process the neural connections behave in ways that can be described by an adaptive control method. The investigation presented in this thesis includes two different sets of experiments. A series of dart throwing experiments took place onboard the space station Mir. Experiments also took place at the Biomechanics lab at MIT, where the subjects performed a series of continuous trajectory tracking movements while a planar robotic manipulandum exerted external torques on the subjects' moving arms. The experimental hypothesis for both experiments is that during the first few trials the subjects will perform poorly trying to follow a prescribed trajectory, or trying to hit a target. A theoretical framework is developed that is a modification of the sliding control method used in robotics. The new control framework is an attempt to explain the adaptive behavior of the subjects. Numerical simulations of the proposed framework are compared with experimental results and predictions from competitive models. The proposed control methodology extends the results of the sliding mode theory to human motor control. The resulting adaptive control model of the motor system is robust to external dynamics, even those of negative gain, uses only position and velocity feedback, and achieves bounded steady-state error without explicit knowledge of the system's nonlinearities. In addition, the experimental and modeling results demonstrate that

  9. Compensation or Restoration: Closed-Loop Feedback of Movement Quality for Assisted Reach-to-Grasp Exercises with a Multi-Joint Arm Exoskeleton

    PubMed Central

    Grimm, Florian; Naros, Georgios; Gharabaghi, Alireza

    2016-01-01

    Assistive technology allows for intensive practice and kinematic measurements during rehabilitation exercises. More recent approaches attach a gravity-compensating multi-joint exoskeleton to the upper extremity to facilitate task-oriented training in three-dimensional space with virtual reality feedback. The movement quality, however, is mostly captured through end-point measures that lack information on proximal inter-joint coordination. This limits the differentiation between compensation strategies and genuine restoration both during the exercise and in the course of rehabilitation. We extended in this proof-of-concept study a commercially available seven degree-of-freedom arm exoskeleton by using the real-time sensor data to display a three-dimensional multi-joint visualization of the user's arm. Ten healthy subjects and three severely affected chronic stroke patients performed reach-to-grasp exercises resembling activities of daily living assisted by the attached exoskeleton and received closed-loop online feedback of the three-dimensional movement in virtual reality. Patients in this pilot study differed significantly with regard to motor performance (accuracy, temporal efficiency, range of motion) and movement quality (proximal inter-joint coordination) from the healthy control group. In the course of 20 training and feedback sessions over 4 weeks, these pathological measures improved significantly toward the reference parameters of healthy participants. It was moreover feasible to capture the evolution of movement pattern kinematics of the shoulder and elbow and to quantify the individual degree of natural movement restoration for each patient. The virtual reality visualization and closed-loop feedback of joint-specific movement kinematics makes it possible to detect compensation strategies and may provide a tool to achieve the rehabilitation goals in accordance with the individual capacity for genuine functional restoration; a proposal that warrants

  10. Compensation or Restoration: Closed-Loop Feedback of Movement Quality for Assisted Reach-to-Grasp Exercises with a Multi-Joint Arm Exoskeleton.

    PubMed

    Grimm, Florian; Naros, Georgios; Gharabaghi, Alireza

    2016-01-01

    Assistive technology allows for intensive practice and kinematic measurements during rehabilitation exercises. More recent approaches attach a gravity-compensating multi-joint exoskeleton to the upper extremity to facilitate task-oriented training in three-dimensional space with virtual reality feedback. The movement quality, however, is mostly captured through end-point measures that lack information on proximal inter-joint coordination. This limits the differentiation between compensation strategies and genuine restoration both during the exercise and in the course of rehabilitation. We extended in this proof-of-concept study a commercially available seven degree-of-freedom arm exoskeleton by using the real-time sensor data to display a three-dimensional multi-joint visualization of the user's arm. Ten healthy subjects and three severely affected chronic stroke patients performed reach-to-grasp exercises resembling activities of daily living assisted by the attached exoskeleton and received closed-loop online feedback of the three-dimensional movement in virtual reality. Patients in this pilot study differed significantly with regard to motor performance (accuracy, temporal efficiency, range of motion) and movement quality (proximal inter-joint coordination) from the healthy control group. In the course of 20 training and feedback sessions over 4 weeks, these pathological measures improved significantly toward the reference parameters of healthy participants. It was moreover feasible to capture the evolution of movement pattern kinematics of the shoulder and elbow and to quantify the individual degree of natural movement restoration for each patient. The virtual reality visualization and closed-loop feedback of joint-specific movement kinematics makes it possible to detect compensation strategies and may provide a tool to achieve the rehabilitation goals in accordance with the individual capacity for genuine functional restoration; a proposal that warrants

  11. Framing activity, meaning, and social-movement participation: the nuclear-disarmament movement

    SciTech Connect

    Benford, R.D. Jr.

    1987-01-01

    Two general objectives are pursued in this four-year qualitative study of the nuclear-disarmament movement: (1) to add to social scientists' understanding of the social dimensions of the interpretation of events, experience, and reality; and (2) to assess theoretically and empirically the role of social movements in the generation of interpretations and meanings, and how these emergent products affect participation in movement activities and campaigns. Twelve local and six national disarmament organizations were studied using a multi-method approach. It entailed systematic analyses of movement documents, formal and informal interviews with participants and activists, and extensive ethnographic participation in local and regional movement activities and campaigns. Guided by the thesis that the acquisition, manipulation, and deployment of symbolic resources are crucial to the mobilization and sustained activation of movement supporters, this research focuses on the ways in which disarmament groups attempted to frame or affect the interpretations of reality held by participants, potential adherents, observers, and antagonists.

  12. Feedback control of arm movements using Neuro-Muscular Electrical Stimulation (NMES) combined with a lockable, passive exoskeleton for gravity compensation

    PubMed Central

    Klauer, Christian; Schauer, Thomas; Reichenfelser, Werner; Karner, Jakob; Zwicker, Sven; Gandolla, Marta; Ambrosini, Emilia; Ferrante, Simona; Hack, Marco; Jedlitschka, Andreas; Duschau-Wicke, Alexander; Gföhler, Margit; Pedrocchi, Alessandra

    2014-01-01

    Within the European project MUNDUS, an assistive framework was developed for the support of arm and hand functions during daily life activities in severely impaired people. This contribution aims at designing a feedback control system for Neuro-Muscular Electrical Stimulation (NMES) to enable reaching functions in people with no residual voluntary control of the arm and shoulder due to high level spinal cord injury. NMES is applied to the deltoids and the biceps muscles and integrated with a three degrees of freedom (DoFs) passive exoskeleton, which partially compensates gravitational forces and allows to lock each DOF. The user is able to choose the target hand position and to trigger actions using an eyetracker system. The target position is selected by using the eyetracker and determined by a marker-based tracking system using Microsoft Kinect. A central controller, i.e., a finite state machine, issues a sequence of basic movement commands to the real-time arm controller. The NMES control algorithm sequentially controls each joint angle while locking the other DoFs. Daily activities, such as drinking, brushing hair, pushing an alarm button, etc., can be supported by the system. The robust and easily tunable control approach was evaluated with five healthy subjects during a drinking task. Subjects were asked to remain passive and to allow NMES to induce the movements. In all of them, the controller was able to perform the task, and a mean hand positioning error of less than five centimeters was achieved. The average total time duration for moving the hand from a rest position to a drinking cup, for moving the cup to the mouth and back, and for finally returning the arm to the rest position was 71 s. PMID:25228853

  13. Feedback control of arm movements using Neuro-Muscular Electrical Stimulation (NMES) combined with a lockable, passive exoskeleton for gravity compensation.

    PubMed

    Klauer, Christian; Schauer, Thomas; Reichenfelser, Werner; Karner, Jakob; Zwicker, Sven; Gandolla, Marta; Ambrosini, Emilia; Ferrante, Simona; Hack, Marco; Jedlitschka, Andreas; Duschau-Wicke, Alexander; Gföhler, Margit; Pedrocchi, Alessandra

    2014-01-01

    Within the European project MUNDUS, an assistive framework was developed for the support of arm and hand functions during daily life activities in severely impaired people. This contribution aims at designing a feedback control system for Neuro-Muscular Electrical Stimulation (NMES) to enable reaching functions in people with no residual voluntary control of the arm and shoulder due to high level spinal cord injury. NMES is applied to the deltoids and the biceps muscles and integrated with a three degrees of freedom (DoFs) passive exoskeleton, which partially compensates gravitational forces and allows to lock each DOF. The user is able to choose the target hand position and to trigger actions using an eyetracker system. The target position is selected by using the eyetracker and determined by a marker-based tracking system using Microsoft Kinect. A central controller, i.e., a finite state machine, issues a sequence of basic movement commands to the real-time arm controller. The NMES control algorithm sequentially controls each joint angle while locking the other DoFs. Daily activities, such as drinking, brushing hair, pushing an alarm button, etc., can be supported by the system. The robust and easily tunable control approach was evaluated with five healthy subjects during a drinking task. Subjects were asked to remain passive and to allow NMES to induce the movements. In all of them, the controller was able to perform the task, and a mean hand positioning error of less than five centimeters was achieved. The average total time duration for moving the hand from a rest position to a drinking cup, for moving the cup to the mouth and back, and for finally returning the arm to the rest position was 71 s. PMID:25228853

  14. Origins and violations of the 2/3 power law in rhythmic three-dimensional arm movements.

    PubMed

    Schaal, S; Sternad, D

    2001-01-01

    The 2/3 power law, the nonlinear relationship between tangential velocity and radius of curvature of the end-effector trajectory, is thought to be a fundamental constraint of the central nervous system in the formation of rhythmic endpoint trajectories. However, studies on the 2/3 power law have been confined largely to planar drawing patterns of relatively small size. With the hypothesis that this strategy overlooks nonlinear effects that are constitutive in movement generation, the present experiments tested the validity of the power law in elliptical patterns that were not confined to a planar surface and which were performed by the unconstrained 7-degrees of freedom (DOF) arm, with significant variations in pattern size and workspace orientation. Data were recorded from five human subjects where the seven joint angles and the endpoint trajectories were analyzed. Additionally, an anthropomorphic 7-DOF robot arm served as a "control subject" whose endpoint trajectories were generated on the basis of the human joint angle data, modeled as simple harmonic oscillations. Analyses of the endpoint trajectories demonstrate that the power law is systematically violated with increasing pattern size, in both exponent and the goodness of fit. The origins of these violations can be explained analytically based on smooth, rhythmic trajectory formation and the kinematic structure of the human arm. We conclude that, in unconstrained rhythmic movements, the power law seems to be a by-product of a movement system that favors smooth trajectories, and that it is unlikely to serve as a primary movement-generating principle. Our data rather suggest that subjects employed smooth oscillatory pattern generators in joint space to realize the required movement patterns. PMID:11204414

  15. Effects of changing stance conditions on anticipatory postural adjustment and reaction time to voluntary arm movement in humans.

    PubMed

    Dietz, V; Kowalewski, R; Nakazawa, K; Colombo, G

    2000-04-15

    1. The effect on reaction time (RT) and anticipatory postural adjustment (APA) of unexpectedly changing stance conditions was studied using a push or pull arm movement task. The aim was to evaluate the modifiability of RT and APA by an external perturbation associated with an automatic compensatory reaction. 2. Subjects standing on a moveable platform were asked to push or pull a rigid handle as quickly and as strongly as possible in response to the 'go-signal', a visual signal from a green or red light-emitting diode. Forward and backward translations of the platform were randomly induced at four time intervals after the go-signal. In some experiments to detect unspecific arousal there were no platform translations but an acoustic signal was given before the go-signal. Surface electromyographic activity (EMG) of upper arm and lower leg muscles was analysed. 3. During the push task both RT and the duration of APA (onset of APA till the force signal indicating hand action) were shorter during backward than during forward translation. During the pull task the effect of platform translations was the reverse. The delay between go-signal and onset of APA remained constant. Consequently, RT and APA became shorter when the platform was translated in the same direction as that in which the upper body was displaced by the push or pull movement, and longer when it was translated in the opposite direction. The effects were maximal when translations were induced 250 ms after the go-signal, but a difference was detected up to 375 ms. 4. Furthermore, with forward and backward platform translations RT was shorter when the translations were induced early rather than late after the go-signal. This was associated with a shortening of the delay between the go-signal and onset of APA, while APA duration remained constant. The shortened RT was in the range of that obtained when an acoustic signal was given just before the go-signal. 5. It is concluded that (i) both the RT and the

  16. Biomechanical aspects of segmented arch mechanics combined with power arm for controlled anterior tooth movement: A three-dimensional finite element study

    PubMed Central

    Ozaki, Hiroya; Tominaga, Jun-ya; Hamanaka, Ryo; Sumi, Mayumi; Chiang, Pao-Chang; Tanaka, Motohiro; Koga, Yoshiyuki

    2015-01-01

    The porpose of this study was to determine the optimal length of power arms for achieving controlled anterior tooth movement in segmented arch mechanics combined with power arm. A three-dimensional finite element method was applied for the simulation of en masse anterior tooth retraction in segmented power arm mechanics. The type of tooth movement, namely, the location of center of rotation of the maxillary central incisor in association with power arm length, was calculated after the retraction force was applied. When a 0.017 × 0.022-in archwire was inserted into the 0.018-in slot bracket, bodily movement was obtained at 9.1 mm length of power arm, namely, at the level of 1.8 mm above the center of resistance. In case a 0.018 × 0.025-in full-size archwire was used, bodily movement of the tooth was produced at the power arm length of 7.0 mm, namely, at the level of 0.3 mm below the center of resistance. Segmented arch mechanics required shorter length of power arms for achieving any type of controlled anterior tooth movement as compared to sliding mechanics. Therefore, this space closing mechanics could be widely applied even for the patients whose gingivobuccal fold is shallow. The segmented arch mechanics combined with power arm could provide higher amount of moment-to-force ratio sufficient for controlled anterior tooth movement without generating friction, and vertical forces when applying retraction force parallel to the occlusal plane. It is, therefore, considered that the segmented power arm mechanics has a simple appliance design and allows more efficient and controllable tooth movement. PMID:25610497

  17. Domestic politics, citizen activism, and U. S. nuclear arms control policy

    SciTech Connect

    Knopf, J.W.

    1991-01-01

    The author seeks to ascertain whether and how citizens' movements concerning nuclear arms control and disarmament affect US arms control policy. The author employs a comparative case study methodology. He examines cases of the Eisenhower and Kennedy Administrations during the period of protest against nuclear testing, and the Reagan Administration during the nuclear weapons freeze campaign and the subsequent campaign for a comprehensive test ban. He hows there are four mechanisms through which public advocacy efforts can influence arms control policy, identifies the conditions under which each can be effective, and details the type of impact each mechanism has. Domestic activism interacts with broader public opinion in a way that creates electoral pressure; with elite-level debates in a way that removes a consensus behind presidential policy or changes the winning coalition in Congress; with bureaucratic politics, by generating ideas that have utility for some agents within the Executive; or with the public diplomacy of foreign governments, especially the Soviet Union. Citizens' movements had an impact on policy in each of the cases studied. The type and extent of impact, and the mechanisms involved in giving activism influence, are different for each case.

  18. Control of reach extent with the paretic and nonparetic arms after unilateral sensorimotor stroke II: planning and adjustments to control movement distance.

    PubMed

    Stewart, Jill Campbell; Gordon, James; Winstein, Carolee J

    2014-11-01

    Nondisabled adults utilize both planning and feedback-based compensatory adjustments to control actual distance moved for skilled reach actions. The purpose of this study was to determine whether individuals post-stroke utilize planning and compensatory adjustments to control movement distance for reaches to targets that vary in distance. Individuals with mild to moderate motor impairment after stroke and nondisabled adults reached with both arms to targets presented at three distances (8, 16, 24 cm). The control of movement distance was compared between arms (control, nonparetic, and paretic) as to the use of planning (correlation of peak acceleration with movement distance), compensatory adjustments prior to peak velocity (correlation of time to peak velocity with movement distance), and compensatory adjustments after peak velocity (variance in movement distance accounted for by deterministic statistical model). The correlation of peak acceleration with movement distance for reaches with the paretic arm was significantly less than controls suggesting a decreased reliance on planning. Feedback-based compensatory adjustments, however, were present prior to and after peak velocity that assisted in achievement of movement distance in a similar manner as controls. Overall reach performance with the paretic arm was impaired, however, as evidenced by greater endpoint error and longer movement times than controls. The decreased use of planning to control movement distance after stroke suggests that the selected motor command was suboptimal in producing the desired movement outcome and may be related to an inability to generate muscle force quickly, lack of knowledge of arm dynamics due to decreased arm use, or lesion characteristics. PMID:25000904

  19. Kinematic analysis of arm and trunk movements in the gait of Parkinson's disease patients based on external signals.

    PubMed

    Son, Hohee; Kim, Eunjung

    2015-12-01

    [Purpose] To investigate the role of external cues on arm swing amplitude and trunk rotation in Parkinson's disease. [Subjects and Methods] The subjects were 13 elderly patients with Parkinson's disease. Subjects walked under four different conditions in a random order: no cue, visual cue, auditory cue, and combined cue. The auditory cue velocity consisted of a metronome beat 20% greater than the subject's general gait speed. For the visual cue condition, bright yellow colored strips of tape placed on the floor at intervals equal to 40% of each subject's height. A motion analysis system was used to measure arm swing amplitude and trunk rotation during walking. [Results] There was a significant difference in the kinematic variables (arm swing amplitude) between different cues, but there was not a significant difference in the kinematic variables with respect to the trunk rotation. [Conclusion] The findings of this study indicate that patients with Parkinson's disease are likely to focus attention on auditory cues. The measurement of arm and trunk kinematics during gait by auditory cues can increase the available methods for the analysis of complex motor programs in movement disorders. PMID:26834352

  20. Kinematic analysis of arm and trunk movements in the gait of Parkinson’s disease patients based on external signals

    PubMed Central

    Son, Hohee; Kim, Eunjung

    2015-01-01

    [Purpose] To investigate the role of external cues on arm swing amplitude and trunk rotation in Parkinson’s disease. [Subjects and Methods] The subjects were 13 elderly patients with Parkinson’s disease. Subjects walked under four different conditions in a random order: no cue, visual cue, auditory cue, and combined cue. The auditory cue velocity consisted of a metronome beat 20% greater than the subject’s general gait speed. For the visual cue condition, bright yellow colored strips of tape placed on the floor at intervals equal to 40% of each subject’s height. A motion analysis system was used to measure arm swing amplitude and trunk rotation during walking. [Results] There was a significant difference in the kinematic variables (arm swing amplitude) between different cues, but there was not a significant difference in the kinematic variables with respect to the trunk rotation. [Conclusion] The findings of this study indicate that patients with Parkinson’s disease are likely to focus attention on auditory cues. The measurement of arm and trunk kinematics during gait by auditory cues can increase the available methods for the analysis of complex motor programs in movement disorders. PMID:26834352

  1. Using Functional Electrical Stimulation Mediated by Iterative Learning Control and Robotics to Improve Arm Movement for People With Multiple Sclerosis.

    PubMed

    Sampson, Patrica; Freeman, Chris; Coote, Susan; Demain, Sara; Feys, Peter; Meadmore, Katie; Hughes, Ann-Marie

    2016-02-01

    Few interventions address multiple sclerosis (MS) arm dysfunction but robotics and functional electrical stimulation (FES) appear promising. This paper investigates the feasibility of combining FES with passive robotic support during virtual reality (VR) training tasks to improve upper limb function in people with multiple sclerosis (pwMS). The system assists patients in following a specified trajectory path, employing an advanced model-based paradigm termed iterative learning control (ILC) to adjust the FES to improve accuracy and maximise voluntary effort. Reaching tasks were repeated six times with ILC learning the optimum control action from previous attempts. A convenience sample of five pwMS was recruited from local MS societies, and the intervention comprised 18 one-hour training sessions over 10 weeks. The accuracy of tracking performance without FES and the amount of FES delivered during training were analyzed using regression analysis. Clinical functioning of the arm was documented before and after treatment with standard tests. Statistically significant results following training included: improved accuracy of tracking performance both when assisted and unassisted by FES; reduction in maximum amount of FES needed to assist tracking; and less impairment in the proximal arm that was trained. The system was well tolerated by all participants with no increase in muscle fatigue reported. This study confirms the feasibility of FES combined with passive robot assistance as a potentially effective intervention to improve arm movement and control in pwMS and provides the basis for a follow-up study. PMID:25823038

  2. Context-dependent adaptation of visually-guided arm movements and vestibular eye movements: role of the cerebellum

    NASA Technical Reports Server (NTRS)

    Lewis, Richard F.

    2003-01-01

    Accurate motor control requires adaptive processes that correct for gradual and rapid perturbations in the properties of the controlled object. The ability to quickly switch between different movement synergies using sensory cues, referred to as context-dependent adaptation, is a subject of considerable interest at present. The potential function of the cerebellum in context-dependent adaptation remains uncertain, but the data reviewed below suggest that it may play a fundamental role in this process.

  3. Software for determining lower extremity muscle-tendon kinematics and moment arm lengths during flexion/extension movements.

    PubMed

    Hawkins, D

    1992-01-01

    A computer program was developed to calculate lower extremity muscle-tendon (MT) kinematics and flexion/extension moment arm (MA) lengths for any subject performing movements constrained to occur in the sagittal plane. The program requires as input subject anthropometric and time series ankle, knee, and hip angle data. Using these data a lower extremity link-segment model is constructed for each time element. Muscle-tendon attachment data and a straight line muscle model are used to calculate MT and flexion/extension moment arm lengths. A finite difference technique is used to determine MT shortening velocity. The utility of this program is demonstrated by calculating MT kinematics and MA lengths for six muscles of a single subject both as a function of joint angles and during gait. PMID:1572164

  4. Coupled bilateral movements and active neuromuscular stimulation: intralimb transfer evidence during bimanual aiming.

    PubMed

    Cauraugh, James H; Kim, Sang Bum; Duley, Aaron

    Motor improvements in chronic stroke recovery accrue from coupled protocols of bilateral movements and active neuromuscular stimulation. This experiment investigated coupled protocols and within-limb transfer between distal and proximal joint combinations. The leading question focused on within-limb transfer of coupled protocols on distal joints to a bimanual aiming task that involved proximal joints. Twenty-six volunteers completed one of three motor recovery protocols according to group assignments: (1) coupled bilateral involved concurrent wrist/finger movements on the unimpaired limb coupled with active stimulation on the impaired limb; (2) unilateral/active stimulation involved neuromuscular electromyogram-triggered stimulation on the impaired wrist/fingers; and (3) no protocol (control group). During the pretest and posttest, subjects performed transverse plane target aiming movements (29 cm) with vision available. The coupled bilateral group showed positive intralimb transfer post-treatment when both arms moved simultaneously. During the posttest, the coupled bilateral group displayed improved movement time, higher peak limb velocity, less variability in peak velocity, and less percentage of total movement time in the deceleration phase than during the pretest. The evidence confirms that within-limb transfer from distal joint training to proximal joint combinations is viable and generalizable in chronic stroke rehabilitation. Moreover, these intralimb transfer findings extend the evidence favoring motor improvements for coupled bilateral protocols during chronic stroke. PMID:15911118

  5. The effect of load on torques in point-to-point arm movements: a 3D model.

    PubMed

    Tibold, Robert; Laczko, Jozsef

    2012-01-01

    A dynamic, 3-dimensional model was developed to simulate slightly restricted (pronation-supination was not allowed) point-to-point movements of the upper limb under different external loads, which were modeled using 3 objects of distinct masses held in the hand. The model considered structural and biomechanical properties of the arm and measured coordinates of joint positions. The model predicted muscle torques generated by muscles and needed to produce the measured rotations in the shoulder and elbow joints. The effect of different object masses on torque profiles, magnitudes, and directions were studied. Correlation analysis has shown that torque profiles in the shoulder and elbow joints are load invariant. The shape of the torque magnitude-time curve is load invariant but it is scaled with the mass of the load. Objects with larger masses are associated with a lower deflection of the elbow torque with respect to the sagittal plane. Torque direction-time curve is load invariant scaled with the mass of the load. The authors propose that the load invariance of the torque magnitude-time curve and torque direction-time curve holds for object transporting arm movements not restricted to a plane. PMID:22938084

  6. The Relationship between Reduplicated Babble Onset and Laterality Biases in Infant Rhythmic Arm Movements

    ERIC Educational Resources Information Center

    Iverson, Jana M.; Hall, Amanda J.; Nickel, Lindsay; Wozniak, Robert H.

    2007-01-01

    This study examined changes in rhythmic arm shaking and laterality biases in infants observed longitudinally at three points: just prior to, at, and just following reduplicated babble onset. Infants (ranging in age from 4 to 9 months at babble onset) were videotaped at home as they played with two visually identical audible and silent rattles…

  7. Failure of Arm Movement Control in Stroke Patients, Characterized by Loss of Complexity

    PubMed Central

    Goh, Segun; Han, Kyungreem; Ryu, Jehkwang; Kim, Seonjin; Choi, MooYoung

    2015-01-01

    We study the mechanism of human arm-posture control by means of nonlinear dynamics and quantitative time series analysis methods. Utilizing linear and nonlinear measures in combination, we find that pathological tremors emerge in patient dynamics and serve as a main feature discriminating between normal and patient groups. The deterministic structure accompanied with loss of complexity inherent in the tremor dynamics is also revealed. To probe the underlying mechanism of the arm-posture dynamics, we further analyze the coupling patterns between joints and components, and discuss their roles in breaking of the organization structure. As a result, we elucidate the mechanisms in the arm-posture dynamics of normal subjects responding to the gravitational force and for the reduction of the dynamic degrees of freedom in the patient dynamics. This study provides an integrated framework for the origin of the loss of complexity in the dynamics of patients as well as the coupling structure in the arm-posture dynamics. PMID:26536132

  8. 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

  9. Brain state-dependent robotic reaching movement with a multi-joint arm exoskeleton: combining brain-machine interfacing and robotic rehabilitation

    PubMed Central

    Brauchle, Daniel; Vukelić, Mathias; Bauer, Robert; Gharabaghi, Alireza

    2015-01-01

    While robot-assisted arm and hand training after stroke allows for intensive task-oriented practice, it has provided only limited additional benefit over dose-matched physiotherapy up to now. These rehabilitation devices are possibly too supportive during the exercises. Neurophysiological signals might be one way of avoiding slacking and providing robotic support only when the brain is particularly responsive to peripheral input. We tested the feasibility of three-dimensional robotic assistance for reaching movements with a multi-joint exoskeleton during motor imagery (MI)-related desynchronization of sensorimotor oscillations in the β-band. We also registered task-related network changes of cortical functional connectivity by electroencephalography via the imaginary part of the coherence function. Healthy subjects and stroke survivors showed similar patterns—but different aptitudes—of controlling the robotic movement. All participants in this pilot study with nine healthy subjects and two stroke patients achieved their maximum performance during the early stages of the task. Robotic control was significantly higher and less variable when proprioceptive feedback was provided in addition to visual feedback, i.e., when the orthosis was actually attached to the subject’s arm during the task. A distributed cortical network of task-related coherent activity in the θ-band showed significant differences between healthy subjects and stroke patients as well as between early and late periods of the task. Brain-robot interfaces (BRIs) may successfully link three-dimensional robotic training to the participants’ efforts and allow for task-oriented practice of activities of daily living with a physiologically controlled multi-joint exoskeleton. Changes of cortical physiology during the task might also help to make subject-specific adjustments of task difficulty and guide adjunct interventions to facilitate motor learning for functional restoration, a proposal that

  10. Neural activation differences in amputees during imitation of intact versus amputee movements

    PubMed Central

    Cusack, William F.; Cope, Michael; Nathanson, Sheryl; Pirouz, Nikta; Kistenberg, Robert; Wheaton, Lewis A.

    2012-01-01

    The mirror neuron system (MNS) has been attributed with increased activation in motor-related cortical areas upon viewing of another's actions. Recent work suggests that limb movements that are similar and dissimilar in appearance to that of the viewer equivalently activate the MNS. It is unclear if this result can be observed in the action encoding areas in amputees who use prosthetic devices. Intact subjects and upper extremity amputee prosthesis users were recruited to view video demonstrations of tools being used by an intact actor and a prosthetic device user. All subjects pantomimed the movements seen in the video while recording electroencephalography (EEG). Intact subjects showed equivalent left parietofrontal activity during imitation planning after watching the intact or prosthetic arm. Likewise, when prosthesis users imitated prosthesis demonstrations, typical left parietofrontal activation was observed. When prosthesis users imitated intact actors, an additional pattern was revealed which showed greater activity in right parietal and occipital regions that are associated with the mentalizing system. This change may be required for prosthesis users to plan imitation movements in which the limb states between the observed and the observer do not match. The finding that prosthesis users imitating other prosthesis users showed typical left parietofrontal activation suggests that these subjects engage normal planning related activity when they are able to imitate a limb matching their own. This result has significant implications on rehabilitation, as standard therapy involves training with an intact occupational therapist, which could necessitate atypical planning mechanisms in amputees when learning to use their prosthesis. PMID:22754516

  11. Hand trajectories of vertical arm movements in one-G and zero-G environments. Evidence for a central representation of gravitational force.

    PubMed

    Papaxanthis, C; Pozzo, T; Popov, K E; McIntyre, J

    1998-06-01

    The purpose of the present experiment was to study the way in which the central nervous system (CNS), represents gravitational force during vertical arm pointing movements. Movements in upward (against gravity) and downward (with gravity) directions, with two different mass loads (hand empty and with a hand-held 0.5-kg weight) were executed by eight subjects in a normal gravitational environment. Movements by two cosmonauts, in the two directions, were also tested in a state of weightlessness. Analyses focused upon finger trajectories in the sagittal plane. Subjects in a normal gravitational environment showed curved paths for both directions and weight conditions. In addition, downward movements showed significantly smaller curvatures than upward movements. Movement times were approximately the same for all the experimental conditions. Curvature differences between upward and downward movements persisted during space flight and immediately postflight. Movement times from both cosmonauts increased slightly during flight, but returned to normal immediately on reentry in a one-G environment. Results from the present study provide evidence that gravity is centrally represented in an anticipatory fashion as a driving force during vertical arm movement planning. PMID:9655235

  12. Robotic arm

    SciTech Connect

    Kwech, H.

    1989-04-18

    A robotic arm positionable within a nuclear vessel by access through a small diameter opening and having a mounting tube supported within the vessel and mounting a plurality of arm sections for movement lengthwise of the mounting tube as well as for movement out of a window provided in the wall of the mounting tube is disclosed. An end effector, such as a grinding head or welding element, at an operating end of the robotic arm, can be located and operated within the nuclear vessel through movement derived from six different axes of motion provided by mounting and drive connections between arm sections of the robotic arm. The movements are achieved by operation of remotely-controllable servo motors, all of which are mounted at a control end of the robotic arm to be outside the nuclear vessel. 23 figs.

  13. Robotic arm

    SciTech Connect

    Kwech, Horst

    1989-04-18

    A robotic arm positionable within a nuclear vessel by access through a small diameter opening and having a mounting tube supported within the vessel and mounting a plurality of arm sections for movement lengthwise of the mounting tube as well as for movement out of a window provided in the wall of the mounting tube. An end effector, such as a grinding head or welding element, at an operating end of the robotic arm, can be located and operated within the nuclear vessel through movement derived from six different axes of motion provided by mounting and drive connections between arm sections of the robotic arm. The movements are achieved by operation of remotely-controllable servo motors, all of which are mounted at a control end of the robotic arm to be outside the nuclear vessel.

  14. Cortical activity in the null space: permitting preparation without movement

    PubMed Central

    Kaufman, Matthew T.; Churchland, Mark M.; Ryu, Stephen I.; Shenoy, Krishna V.

    2014-01-01

    Neural circuits must perform computations and then selectively output the results to other circuits. Yet synapses do not change radically at millisecond timescales. A key question then is: how is communication between neural circuits controlled? In motor control, brain areas directly involved in driving movement are active well before movement begins. Muscle activity is some readout of neural activity, yet remains largely unchanged during preparation. Here we find that during preparation, while the monkey holds still, changes in motor cortical activity cancel out at the level of these population readouts. Motor cortex can thereby prepare the movement without prematurely causing it. Further, we found evidence that this mechanism also operates in dorsal premotor cortex (PMd), largely accounting for how preparatory activity is attenuated in primary motor cortex (M1). Selective use of “output-null” vs. “output-potent” patterns of activity may thus help control communication to the muscles and between these brain areas. PMID:24487233

  15. Control of multi-joint arm movements for the manipulation of touch in keystroke by expert pianists

    PubMed Central

    2010-01-01

    Background Production of a variety of finger-key touches in the piano is essential for expressive musical performance. However, it remains unknown how expert pianists control multi-joint finger and arm movements for manipulating the touch. The present study investigated differences in kinematics and kinetics of the upper-limb movements while expert pianists were depressing a key with two different touches: pressed and struck. The former starts key-depression with the finger-tip contacting the key, whereas the latter involves preparatory arm-lift before striking the key. To determine the effect of individual muscular torque (MUS) as well as non-muscular torques on joint acceleration, we performed a series of inverse and forward dynamics computations. Results The pressed touch showed smaller elbow extension velocity, and larger shoulder and finger flexion velocities during key-depression compared with the struck touch. The former touch also showed smaller elbow extension acceleration directly attributed to the shoulder MUS. In contrast, the shoulder flexion acceleration induced by elbow and wrist MUS was greater for the pressed touch than the struck touch. Towards the goal of producing the target finger-key contact dynamics, the pressed and struck touches effectively took advantage of the distal-to-proximal and proximal-to-distal inter-segmental dynamics, respectively. Furthermore, a psychoacoustic experiment confirmed that a tone elicited by the pressed touch was perceived softer than that by the struck touch. Conclusion The present findings suggest that manipulation of tone timbre depends on control of inter-segmental dynamics in piano keystroke. PMID:20630085

  16. An EMG-level muscle model for a fast arm movement to target.

    PubMed

    Kilmer, W; Kroll, W; Congdon, V

    1982-01-01

    A model of human muscle action is presented for a maximally fast, large-amplitude forearm movement to target. The inputs to the model are approximately the biceps and triceps EMG envelopes over a single movement. The model's output gives the corresponding displacement angle of the forearm about a fixed elbow position as a function of time. The idea of the model is to conceive of both EMG input drives as successions of millisecond input pulses, with each pulse resulting in a muscle tension twitch. Every twitch is amplitude-scaled, parametrically-shaped, and duration-limited as a function of the muscle's contractile history thus far in the movement. The muscle tension at any time t is the sum of the residual tension levels of all twitches begun before t. The model was developed and tested with special reference to two subjects: one, according to the model dynamics, was a comparatively slow-twitch type and the other modelled as a fast-twitch type. Good agreement was found between model output and subject response data whenever the subject's EMG's were "synchronous". The model can be used to characterize each subject's responses by a suite of twitch characteristics. This will enable us to check the accepted but now suspect correlation between muscle biopsy- and performance-determined muscle twitch type. PMID:7093365

  17. Active movement restores veridical event-timing after tactile adaptation.

    PubMed

    Tomassini, Alice; Gori, Monica; Burr, David; Sandini, Giulio; Morrone, Maria Concetta

    2012-10-01

    Growing evidence suggests that time in the subsecond range is tightly linked to sensory processing. Event-time can be distorted by sensory adaptation, and many temporal illusions can accompany action execution. In this study, we show that adaptation to tactile motion causes a strong contraction of the apparent duration of tactile stimuli. However, when subjects make a voluntary motor act before judging the duration, it annuls the adaptation-induced temporal distortion, reestablishing veridical event-time. The movement needs to be performed actively by the subject: passive movement of similar magnitude and dynamics has no effect on adaptation, showing that it is the motor commands themselves, rather than reafferent signals from body movement, which reset the adaptation for tactile duration. No other concomitant perceptual changes were reported (such as apparent speed or enhanced temporal discrimination), ruling out a generalized effect of body movement on somatosensory processing. We suggest that active movement resets timing mechanisms in preparation for the new scenario that the movement will cause, eliminating inappropriate biases in perceived time. Our brain seems to utilize the intention-to-move signals to retune its perceptual machinery appropriately, to prepare to extract new temporal information. PMID:22832572

  18. The Resonating Arm Exerciser: design and pilot testing of a mechanically passive rehabilitation device that mimics robotic active assistance

    PubMed Central

    2013-01-01

    Background Robotic arm therapy devices that incorporate actuated assistance can enhance arm recovery, motivate patients to practice, and allow therapists to deliver semi-autonomous training. However, because such devices are often complex and actively apply forces, they have not achieved widespread use in rehabilitation clinics or at home. This paper describes the design and pilot testing of a simple, mechanically passive device that provides robot-like assistance for active arm training using the principle of mechanical resonance. Methods The Resonating Arm Exerciser (RAE) consists of a lever that attaches to the push rim of a wheelchair, a forearm support, and an elastic band that stores energy. Patients push and pull on the lever to roll the wheelchair back and forth by about 20 cm around a neutral position. We performed two separate pilot studies of the device. In the first, we tested whether the predicted resonant properties of RAE amplified a user’s arm mobility by comparing his or her active range of motion (AROM) in the device achieved during a single, sustained push and pull to the AROM achieved during rocking. In a second pilot study designed to test the therapeutic potential of the device, eight participants with chronic stroke (35 ± 24 months since injury) and a mean, stable, initial upper extremity Fugl-Meyer (FM) score of 17 ± 8 / 66 exercised with RAE for eight 45 minute sessions over three weeks. The primary outcome measure was the average AROM measured with a tilt sensor during a one minute test, and the secondary outcome measures were the FM score and the visual analog scale for arm pain. Results In the first pilot study, we found people with a severe motor impairment after stroke intuitively found the resonant frequency of the chair, and the mechanical resonance of RAE amplified their arm AROM by a factor of about 2. In the second pilot study, AROM increased by 66% ± 20% (p = 0.003). The mean FM score increase was 8.5 ± 4 pts (p = 0

  19. Sensory Agreement Guides Kinetic Energy Optimization of Arm Movements during Object Manipulation

    PubMed Central

    Farshchiansadegh, Ali; Melendez-Calderon, Alejandro; Ranganathan, Rajiv; Murphey, Todd D.; Mussa-Ivaldi, Ferdinando A.

    2016-01-01

    The laws of physics establish the energetic efficiency of our movements. In some cases, like locomotion, the mechanics of the body dominate in determining the energetically optimal course of action. In other tasks, such as manipulation, energetic costs depend critically upon the variable properties of objects in the environment. Can the brain identify and follow energy-optimal motions when these motions require moving along unfamiliar trajectories? What feedback information is required for such optimal behavior to occur? To answer these questions, we asked participants to move their dominant hand between different positions while holding a virtual mechanical system with complex dynamics (a planar double pendulum). In this task, trajectories of minimum kinetic energy were along curvilinear paths. Our findings demonstrate that participants were capable of finding the energy-optimal paths, but only when provided with veridical visual and haptic information pertaining to the object, lacking which the trajectories were executed along rectilinear paths. PMID:27035587

  20. Sensory Agreement Guides Kinetic Energy Optimization of Arm Movements during Object Manipulation.

    PubMed

    Farshchiansadegh, Ali; Melendez-Calderon, Alejandro; Ranganathan, Rajiv; Murphey, Todd D; Mussa-Ivaldi, Ferdinando A

    2016-04-01

    The laws of physics establish the energetic efficiency of our movements. In some cases, like locomotion, the mechanics of the body dominate in determining the energetically optimal course of action. In other tasks, such as manipulation, energetic costs depend critically upon the variable properties of objects in the environment. Can the brain identify and follow energy-optimal motions when these motions require moving along unfamiliar trajectories? What feedback information is required for such optimal behavior to occur? To answer these questions, we asked participants to move their dominant hand between different positions while holding a virtual mechanical system with complex dynamics (a planar double pendulum). In this task, trajectories of minimum kinetic energy were along curvilinear paths. Our findings demonstrate that participants were capable of finding the energy-optimal paths, but only when provided with veridical visual and haptic information pertaining to the object, lacking which the trajectories were executed along rectilinear paths. PMID:27035587

  1. Effect of active arm swing to local dynamic stability during walking.

    PubMed

    Wu, Yu; Li, Yue; Liu, An-Min; Xiao, Fei; Wang, Yin-Zhi; Hu, Fei; Chen, Jin-Ling; Dai, Ke-Rong; Gu, Dong-Yun

    2016-02-01

    Arm swing is an essential component in regulating dynamic stability of the whole body during walking, while the contribution of active arm swing to local dynamic stability of different motion segments remains unclear. This study investigated the effects of arm swing under natural arm swing condition and active arm swing condition on local dynamic stability and gait variability of the trunk segments (C7 and T10 joint) and lower extremity joints (hip, knee and ankle joint). The local divergence exponents (λs) and mean standard deviation over strides (MeanSD) of 24 young healthy adults were calculated while they were walking on treadmill with two arm swing conditions at their preferred walking speed (PWS). We found that in medial-lateral direction, both λs and MeanSD values of the trunk segments (C7 and T10 joint) in active arm swing condition were significantly lower than those in natural arm swing condition (p<0.05), while no significant difference of λs or MeanSD in lower extremity joints (hip, knee and ankle joint) was found between two arm swing conditions (p>0.05, respectively). In anterior-posterior and vertical direction, neither λs nor MeanSD values of all body segments showed significant difference between two arm swing conditions (p>0.05, respectively). These findings indicate that active arm swing may help to improve the local dynamic stability of the trunk segments in medial-lateral direction. PMID:26615477

  2. Voice-Activated Lightweight Reacher to Assist with Upper Extremity Movement Limitations: A Case Study.

    PubMed

    Khalid, Umer; Conti, Gerry E; Erlandson, Robert F; Ellis, Richard D; Brown, Vince; Pandya, Abhilash K

    2015-01-01

    The focus of this research was to design a functional and user-friendly reacher for people with spinal cord injuries (SCIs). Engineering advancements have taken assistive robotics to new dimensions. Technologies such as wheelchair robotics and myo-electronically controlled systems have opened up a wide range of new applications to assist people with physical disabilities. Similarly, exo-skeletal limbs and body suits have provided new foundations from which technologies can aid function. Unfortunately, these devices have issues of usability, weight, and discomfort with donning. The Smart Assistive Reacher Arm (SARA) system, developed in this research, is a voice-activated, lightweight, mobile device that can be used when needed. SARA was built to help overcome daily reach challenges faced by individuals with limited arm and hand movement capability, such as people with cervical level 5-6 (C5-6) SCI. This article shows that a functional reacher arm with voice control can be beneficial for this population. Comparison study with healthy participants and an SCI participant shows that, when using SARA, a person with SCI can perform simple reach and grasp tasks independently, without someone else's help. This suggests that the interface is intuitive and can be easily used to a high level of proficiency by a SCI individual. PMID:26132355

  3. The neck region of the myosin motor domain acts as a lever arm to generate movement.

    PubMed Central

    Uyeda, T Q; Abramson, P D; Spudich, J A

    1996-01-01

    The myosin head consists of a globular catalytic domain that binds actin and hydrolyzes ATP and a neck domain that consists of essential and regulatory light chains bound to a long alpha-helical portion of the heavy chain. The swinging neck-level model assumes that a swinging motion of the neck relative to the catalytic domain is the origin of movement. This model predicts that the step size, and consequently the sliding velocity, are linearly related to the length of the neck. We have tested this point by characterizing a series of mutant Dictyostelium myosins that have different neck lengths. The 2xELCBS mutant has an extra binding site for essential light chain. The delta RLCBS mutant myosin has an internal deletion that removes the regulatory light chain binding site. The delta BLCBS mutant lacks both light chain binding sites. Wild-type myosin and these mutant myosins were subjected to the sliding filament in vitro motility assay. As expected, mutants with shorter necks move slower than wild-type myosin in vitro. Most significantly, a mutant with a longer neck moves faster than the wild type, and the sliding velocities of these myosins are linearly related to the neck length, as predicted by the swinging neck-lever model. A simple extrapolation to zero speed predicts that the fulcrum point is in the vicinity of the SH1-SH2 region in the catalytic domain. Images Fig. 1 Fig. 2 Fig. 3 PMID:8633089

  4. Learning Through Movement: Teaching Cognitive Content through Physical Activities.

    ERIC Educational Resources Information Center

    Werner, Peter H.; Burton, Elsie C.

    Action-oriented learning activities are focused on in this book which attempts to outline an approach for stimulating and motivating children to learn through movement. The book is divided into five parts, each dealing with an aspect of the elementary school curriculum. Part one is concerned with the language arts and is divided into three…

  5. CHILDREN'S MOVEMENT SKILLS WHEN PLAYING ACTIVE VIDEO GAMES.

    PubMed

    Hulteen, Ryan M; Johnson, Tara M; Ridgers, Nicola D; Mellecker, Robin R; Barnett, Lisa M

    2015-12-01

    Active video games (AVGs) may be useful for movement skill practice. This study examined children's skill execution while playing Xbox Kinect™ and during movement skill assessment. Nineteen children (10 boys, 9 girls; M age=7.9 yr., SD=1.4) had their skills assessed before AVG play and then were observed once a week for 6 wk. while playing AVGs for 50 min. While AVG play showed evidence of correct skill performance (at least 30-50% of the time when playing table tennis, tennis, and baseball), nearly all skills were more correctly performed during skill assessment (generally more than 50% of the time). This study may help researchers to better understand the role AVGs could play in enhancing real life movement skills. PMID:26654991

  6. Active sensing via movement shapes spatiotemporal patterns of sensory feedback.

    PubMed

    Stamper, Sarah A; Roth, Eatai; Cowan, Noah J; Fortune, Eric S

    2012-05-01

    Previous work has shown that animals alter their locomotor behavior to increase sensing volumes. However, an animal's own movement also determines the spatial and temporal dynamics of sensory feedback. Because each sensory modality has unique spatiotemporal properties, movement has differential and potentially independent effects on each sensory system. Here we show that weakly electric fish dramatically adjust their locomotor behavior in relation to changes of modality-specific information in a task in which increasing sensory volume is irrelevant. We varied sensory information during a refuge-tracking task by changing illumination (vision) and conductivity (electroreception). The gain between refuge movement stimuli and fish tracking responses was functionally identical across all sensory conditions. However, there was a significant increase in the tracking error in the dark (no visual cues). This was a result of spontaneous whole-body oscillations (0.1 to 1 Hz) produced by the fish. These movements were costly: in the dark, fish swam over three times further when tracking and produced more net positive mechanical work. The magnitudes of these oscillations increased as electrosensory salience was degraded via increases in conductivity. In addition, tail bending (1.5 to 2.35 Hz), which has been reported to enhance electrosensory perception, occurred only during trials in the dark. These data show that both categories of movements - whole-body oscillations and tail bends - actively shape the spatiotemporal dynamics of electrosensory feedback. PMID:22496294

  7. Building a realistic neuronal model that simulates multi-joint arm and hand movements in 3D space.

    PubMed

    Alstermark, Bror; Lan, Ning; Pettersson, Lars-Gunnar

    2007-11-01

    The question as to how the brain controls voluntary movements of the arm and hand still remains largely unsolved despite much research focused on behavioral studies, neurophysiological investigations, and neuronal modeling in computer science. This is because behavioral studies are usually performed without detailed knowledge of the underlying neuronal networks, neurophysiological studies often lack an understanding of the function, and neuronal models are frequently focused on a particular control problem with restricted knowledge of the underlying neuronal networks involved. Therefore, it seems appropriate to start by trying to integrate knowledge of neuronal networks with known function and computer based neuronal models to seek more realistic models that can better control robots or artificial limbs and hands. We propose to combine knowledge of a behavioral model for reaching with the hand toward an object, which is based on detailed knowledge of the underlying neuronal network, and a neuronal model that includes several functional levels, from the planning level via intermediate levels to the final level of control of motoneurons and muscles. PMID:19404420

  8. Movement-related cortical activation in familial Parkinson disease.

    PubMed

    Delval, A; Defebvre, L; Labyt, E; Douay, X; Bourriez, J-L; Waucquiez, N; Derambure, P; Destée, A

    2006-09-26

    We sought to determine whether or not first-degree relatives of patients with familial Parkinson disease (FDRs) present impaired movement-related cortical activity. We studied 10 familial Parkinson disease subjects, 10 FDRs, and 10 controls and analyzed event-related mu desynchronization (ERD) and beta synchronization. Forty percent FDRs presented reduced premovement mu ERD latency, suggesting that premovement cortical activation is impaired in FDRs. PMID:17000986

  9. The application of active side arm controllers in helicopters

    NASA Technical Reports Server (NTRS)

    Knorr, R.; Melz, C.; Faulkner, A.; Obermayer, M.

    1993-01-01

    Eurocopter Deutschland (ECD) started simulation trials to investigate the particular problems of Side Arm Controllers (SAC) applied to helicopters. Two simulation trials have been performed. In the first trial, the handling characteristics of a 'passive' SAC and the basic requirements for the application of an 'active' SAC were evaluated in pilot-in-the-loop simulations, performing the tasks in a realistic scenario representing typical phases of a transport mission. The second simulation trial investigated the general control characteristics of the 'active' in comparison to the 'passive' control principle. A description of the SACs developed by ECD and the principle of the 'passive' and 'active' control concept is given, as well as specific ratings for the investigated dynamic and ergonomic parameters effecting SAC characteristics. The experimental arrangements, as well as the trials procedures of both simulation phases, are described and the results achieved are discussed emphasizing the advantages of the 'active' as opposed to the 'passive' SAC concept. This also includes the presentation of some critical aspects still to be improved and proposals to solve them.

  10. The Costs and Risks of Social Activism: A Study of Sanctuary Movement Activism.

    ERIC Educational Resources Information Center

    Wiltfang, Gregory L.; McAdam, Doug

    1991-01-01

    Among 141 activists with varying levels of participation in the sanctuary movement, biographical availability factors--younger age and greater discretionary time--best predict high-cost activism (more hours devoted to the movement), whereas ideological socialization factors best predict high-risk activism (direct contact with refugees). Contains…

  11. Effects of drought on desert tortoise movement and activity

    USGS Publications Warehouse

    Duda, J.J.; Krzysik, A.J.; Freilich, J.E.

    1999-01-01

    We monitored movement and activity patterns of 38 desert tortoises (Gopherus agassizii) at 2 locations in the southcentral Mojave Desert during 2 consecutive years differing markedly in winter rainfall. During the first year, winter precipitation was 225% greater than the long-term average for this region, whereas a drought the following year resulted in precipitation that was 25% of the long-term average. These winter rains produced 2 distinct patterns of annual plant productivity: a bloom of annuals the first year, followed by their complete absence the second year. As measured by radiotelemetry, home range size, the number of different burrows used, average distances traveled per day, and levels of surface versus burrow activity were significantly reduced in both populations during the drought year. The pooled distribution of between-observation distances traveled showed a shift favoring shorter-distance movements during the drought year. Differences in levels of winter precipitation between years and the resulting variation of winter annual biomass in the spring appear to play a significant role in desert tortoise movement and activity patterns. Future management and conservation plans for the desert tortoise should consider weather and productivity as important factors influencing annual home range size, number of burrows used, average distances traveled, and activity levels.

  12. Intra-Cyclic Phases of Arm-Leg Movement and Index of Coordination in Relation to Sprint Breaststroke Swimming in Young Swimmers

    PubMed Central

    Strzala, Marek; Krezalek, Piotr; Glab, Grzegorz; Kaca, Marcin; Ostrowski, Andrzej; Stanula, Arkadiusz; Tyka, Anna K.

    2013-01-01

    Despite the limitations set by FINA regulations, execution technique in breaststroke swimming is being improved thanks to more and more advanced analyses of the efficiency of the swimmer’s movements. The aim of this study was to detect the parameters of the time structure of the cycle correlated with the maximal swimming speed at the of 50 meters distance, in order to focus to specific technical aspects in the breaststroke training. In the group of 23 participants, between the age of 15.0 ± 1.17, the breaststroke cycle movement of the arms and legs was divided into two phases: propulsive or non-propulsive. In addition, indices characterizing the temporal coordination of movements of the upper limbs in relation to the lower limbs were distinguished: 1) Arm-Leg Lag - determines the interval between the phases of propulsion generated by upper and lower limbs; 2) Glide or Overlap - the inter-cyclic glide or overlap of the propulsive movement of the upper on lower limbs. Significant dependence was noted between the swim speed (V50surface breast) and the percentage of time of the arm propulsive in-sweep phase 0.64, p < 0.01. A significant correlation was observed between the V50surface breast with the percentage of partially surfaced hand phase of arm recovery 0.54, p < 0.01. Correlation between total leg propulsion and non-propulsion phases with V50surface breast was 0.49 and -0.49 respectively, both p < 0.01. The Glide or Overlap index was significantly related to the swimming speed V50surface breast 0.48, p < 0.05. This type of analysis suggests how to refine the swimming technique, with the goal to improve the current speed capabilities; furthermore the results also indicate the direction of its development in the future swimmers of the group studied. Key Points This study investigated the influence of the inter- and intra-cyclic time structure of the movements in sprint breaststroke swimming. The distinction of the operations phases of the upper limbs in the

  13. Two-stage muscle activity responses in decisions about leg movement adjustments during trip recovery.

    PubMed

    Potocanac, Zrinka; Pijnappels, Mirjam; Verschueren, Sabine; van Dieën, Jaap; Duysens, Jacques

    2016-01-01

    Studies on neural decision making mostly investigated fast corrective adjustments of arm movements. However, fast leg movement corrections deserve attention as well, since they are often required to avoid falling after balance perturbations. The present study aimed at elucidating the mechanisms behind fast corrections of tripping responses by analyzing the concomitant leg muscle activity changes. This was investigated in seven young adults who were tripped in between normal walking trials and took a recovery step by elevating the tripped leg over the obstacle. In some trials, a forbidden landing zone (FZ) was presented behind the obstacle, at the subjects' preferred foot landing position, forcing a step correction. Muscle activity of the tripped leg gastrocnemius medialis (iGM), tibialis anterior (iTA), rectus femoris (iRF), and biceps femoris (iBF) muscles was compared between normal trips presented before any FZ appearance, trips with a FZ, and normal trips presented in between trips with a FZ ("catch" trials). When faced with a real or expected (catch trials) FZ, subjects shortened their recovery steps. The underlying changes in muscle activity consisted of two stages. The first stage involved reduced iGM activity, occurring at a latency shorter than voluntary reaction, followed by reduced iTA and increased iBF and iGM activities occurring at longer latencies. The fast response was not related to step shortening, but longer latency responses clearly were functional. We suggest that the initial response possibly acts as a "pause," allowing the nervous system to integrate the necessary information and prepare the subsequent, functional movement adjustment. PMID:26561597

  14. Muscle activity detection in electromyograms recorded during periodic movements.

    PubMed

    Spulák, Daniel; Cmejla, Roman; Bačáková, Radka; Kračmar, Bronislav; Satrapová, Lenka; Novotný, Petr

    2014-04-01

    Muscle coordination during periodic movements is often studied using the average envelope of the electromyographic (EMG) signal. We show that this method causes a loss of important information, and potentially gives rise to errors in analysis of muscle activity coordination. We created four simulated two-channel surface EMG signals, in order to compare the results of muscle onset/cessation detection, performed on the average EMG envelope and the EMG envelopes in every single movement cycle. Our results show that the common method using the average EMG envelope is unable to reveal certain important characteristics of the EMG signals, while the analysis performed on individual cycles accentuates this information. This ability was verified on 16-channel surface EMGs obtained during walking and cycling. By detecting muscle activity in individual movement cycles, we could observe fine changes in muscle coordination. Moreover, muscles with questionable reliability of activity detection were distinguished and highlighted in the presented summary figures. In the second part of the paper, our publicly available set of MATLAB files for surface EMG signal processing is described. PMID:24561347

  15. Integration of Gravitational Torques in Cerebellar Pathways Allows for the Dynamic Inverse Computation of Vertical Pointing Movements of a Robot Arm

    PubMed Central

    Gentili, Rodolphe J.; Papaxanthis, Charalambos; Ebadzadeh, Mehdi; Eskiizmirliler, Selim; Ouanezar, Sofiane; Darlot, Christian

    2009-01-01

    Background Several authors suggested that gravitational forces are centrally represented in the brain for planning, control and sensorimotor predictions of movements. Furthermore, some studies proposed that the cerebellum computes the inverse dynamics (internal inverse model) whereas others suggested that it computes sensorimotor predictions (internal forward model). Methodology/Principal Findings This study proposes a model of cerebellar pathways deduced from both biological and physical constraints. The model learns the dynamic inverse computation of the effect of gravitational torques from its sensorimotor predictions without calculating an explicit inverse computation. By using supervised learning, this model learns to control an anthropomorphic robot arm actuated by two antagonists McKibben artificial muscles. This was achieved by using internal parallel feedback loops containing neural networks which anticipate the sensorimotor consequences of the neural commands. The artificial neural networks architecture was similar to the large-scale connectivity of the cerebellar cortex. Movements in the sagittal plane were performed during three sessions combining different initial positions, amplitudes and directions of movements to vary the effects of the gravitational torques applied to the robotic arm. The results show that this model acquired an internal representation of the gravitational effects during vertical arm pointing movements. Conclusions/Significance This is consistent with the proposal that the cerebellar cortex contains an internal representation of gravitational torques which is encoded through a learning process. Furthermore, this model suggests that the cerebellum performs the inverse dynamics computation based on sensorimotor predictions. This highlights the importance of sensorimotor predictions of gravitational torques acting on upper limb movements performed in the gravitational field. PMID:19384420

  16. 75 FR 54599 - Takes of Marine Mammals Incidental to Specified Activities; Construction of the Knik Arm Crossing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-08

    ... Specified Activities; Construction of the Knik Arm Crossing, Alaska AGENCY: National Marine Fisheries... received a request from the Knik Arm Bridge Toll Authority (KABATA), in coordination with the Department of... construction of a bridge across Knik Arm, named the Knik Arm Crossing, Alaska, over the course of...

  17. Muscle spindle activity in man during voluntary fast alternating movements.

    PubMed Central

    Hagbarth, K E; Wallen, G; Löfstedt, L

    1975-01-01

    Single unit activity in primary spindle afferent nerve fibres from finger and foot flexors was recorded with tungsten microelectrodes inserted into the median and peroneal nerves of healthy subjects. During voluntary fast alternating finger and foot movements, simulating the tremor of Parkinsonism, two types of discharges were seen in the Ia afferent fibres: (1) stretch responses occurring during the flexor relaxation phases, and (2) discharges occurring during the flexor contraction phases. Contrary to the stretch responses the spindle contraction discharges could be eliminated by a partial lidocaine block of the muscle nerve proximal to the recording site, indicating that they resulted from fusimotor activation of intrafusal fibres. On the basis of the temporal relations between the beginning and end of individual EMG-bursts, the start of the spindle contraction discharges and the latency of the stretch reflex in the muscles concerned, the following conclusions were drawn: the recurrent extrafusal contractions in movements of this type are initiated by the fast direct alpha route, but individual contraction phases generally last long enough to be influenced subsequently by the coactivated fusimotor loop through the spindles. It is postulated that this gamma loop influence during alternating movements helps to keep flexor and extensor muscles working in a regular reciprocal fashion with contractions adjusted in strength to the external loads. Images PMID:125782

  18. Relationship between stretch reflex thresholds and voluntary arm muscle activation in patients with spasticity.

    PubMed

    Musampa, Nadine K; Mathieu, Pierre A; Levin, Mindy F

    2007-08-01

    Previous studies have shown that deficits in agonist-antagonist muscle activation in the single-joint elbow system in patients with spastic hemiparesis are directly related to limitations in the range of regulation of the thresholds of muscle activation. We extended these findings to the double-joint, shoulder-elbow system in these patients. Ten non-disabled individuals and 11 stroke survivors with spasticity in upper limb muscles participated. Stroke survivors had sustained a single unilateral stroke 6-36 months previously, had full pain-free passive range of motion of the affected shoulder and elbow and had some voluntary control of the arm. EMG activity from four elbow and two shoulder muscles was recorded during quasi-static (<5 degrees /s) stretching of elbow flexors/extensors and during slow voluntary elbow flexion/extension movement through full range. Stretches and active movements were initiated from full elbow flexion or extension with the shoulder in three different initial positions (60 degrees , 90 degrees , 145 degrees horizontal abduction). SRTs were defined as the elbow angle at which EMG signals began to exceed 2SD of background noise. SRT angles obtained by passive muscle stretch were compared with the angles at which the respective muscles became activated during voluntary elbow movements. SRTs in elbow flexors were correlated with clinical spasticity scores. SRTs of elbow flexors and extensors were within the biomechanical range of the joint and varied with changes in the shoulder angle in all subjects with hemiparesis but could not be reached in this range in all healthy subjects when muscles were initially relaxed. In patients, limitations in the regulation of SRTs resulted in a subdivision of all-possible shoulder-elbow arm configurations into two areas, one in which spasticity was present ("spatial spasticity zone") and another in which it was absent. Spatial spasticity zones were different for different muscles in different patients but

  19. Designing Movement Activities to Develop Children's Creativity in Early Childhood Education

    ERIC Educational Resources Information Center

    Cheung, Rebecca Hun Ping

    2010-01-01

    This article describes the introduction of creative movement activity in three Hong Kong kindergartens to promote children's creativity. The purposes of the study were to examine the effectiveness of creative movement activity in promoting children's creativity and teachers' perceptions of the activities. The movement activities were designed…

  20. Movements and activity of juvenile Brown Treesnakes (Boiga irregularis)

    USGS Publications Warehouse

    Lardner, Bjorn; Savidge, Julie A.; Reed, Robert N.; Rodda, Gordon H.

    2014-01-01

    Understanding the spatial ecology and foraging strategy of invasive animals is essential for success in control or eradication. We studied movements and activity in juvenile Brown Treesnakes on Guam, as this population segment has proven particularly difficult to control. Distance between daytime refugia (from telemetry of 18 juveniles, 423-800 mm snout-vent length) ranged from 0-118 m (n  =  86), with a grand mean of 43 m. There were tendencies for shorter snake movements on nights directly following a full moon and on dry nights, but variation among snakes was of a larger magnitude and would greatly reduce chances to detect moon or rain effects unless corrected for. Snake activity was estimated from audio recordings of signals from “tipping” radio transmitters, analyzed for pulse period and amplitude. Activity was highest in the hours immediately after sunset, and gradually declined throughout the night before dropping abruptly in conjunction with sunrise. Snake activity was higher on rainy nights, and tended to be highest during waning moons and when the moon was below the horizon. We conclude that small Brown Treesnakes forage actively and appear to move far enough to regularly encounter the traps and bait used on Guam for control purposes, suggesting that alternative explanations are required for their low capture rates with these control tools.

  1. Controlled movement processing: superior colliculus activity associated with countermanded saccades.

    PubMed

    Paré, Martin; Hanes, Doug P

    2003-07-23

    We investigated whether the monkey superior colliculus (SC), an important midbrain structure for the regulation of saccadic eye movements, contains neurons with activity patterns sufficient to control both the cancellation and the production of saccades. We used a countermanding task to manipulate the probability that, after the presentation of a stop signal, the monkeys canceled a saccade that was planned in response to an eccentric visual stimulus. By modeling each animal's behavioral responses, with a race between GO and STOP processes leading up to either saccade initiation or cancellation, we estimated that saccade cancellation took on average 110 msec. Neurons recorded in the superior colliculus intermediate layers during this task exhibited the discharge properties expected from neurons closely involved in behavioral control. Both saccade- and fixation-related discharged differently when saccades were counter-manded instead of executed, and the time at which they changed their activity preceded the behavioral estimate of saccade cancellation obtained from the same trials by 10 and 13 msec, respectively. Furthermore, these intervals exceed the minimal amount of time needed for SC activity to influence eye movements. The additional observation that saccade-related neurons discharged significantly less when saccades were countermanded instead of executed suggests that saccades are triggered when these neurons reach a critical activation level. Altogether, these findings provide solid evidence that the superior colliculus contains the necessary neural signals to be directly involved in the decision process that regulates whether a saccade is to be produced. PMID:12878689

  2. Changes in music tempo entrain movement related brain activity.

    PubMed

    Daly, Ian; Hallowell, James; Hwang, Faustina; Kirke, Alexis; Malik, Asad; Roesch, Etienne; Weaver, James; Williams, Duncan; Miranda, Eduardo; Nasuto, Slawomir J

    2014-01-01

    The neural mechanisms of music listening and appreciation are not yet completely understood. Based on the apparent relationship between the beats per minute (tempo) of music and the desire to move (for example feet tapping) induced while listening to that music it is hypothesised that musical tempo may evoke movement related activity in the brain. Participants are instructed to listen, without moving, to a large range of musical pieces spanning a range of styles and tempos during an electroencephalogram (EEG) experiment. Event-related desynchronisation (ERD) in the EEG is observed to correlate significantly with the variance of the tempo of the musical stimuli. This suggests that the dynamics of the beat of the music may induce movement related brain activity in the motor cortex. Furthermore, significant correlations are observed between EEG activity in the alpha band over the motor cortex and the bandpower of the music in the same frequency band over time. This relationship is observed to correlate with the strength of the ERD, suggesting entrainment of motor cortical activity relates to increased ERD strength. PMID:25571015

  3. Research Activities at Fermilab for Big Data Movement

    SciTech Connect

    Mhashilkar, Parag; Wu, Wenji; Kim, Hyun W; Garzoglio, Gabriele; Dykstra, Dave; Slyz, Marko; DeMar, Phil

    2013-01-01

    Adaptation of 100GE Networking Infrastructure is the next step towards management of Big Data. Being the US Tier-1 Center for the Large Hadron Collider's (LHC) Compact Muon Solenoid (CMS) experiment and the central data center for several other large-scale research collaborations, Fermilab has to constantly deal with the scaling and wide-area distribution challenges of the big data. In this paper, we will describe some of the challenges involved in the movement of big data over 100GE infrastructure and the research activities at Fermilab to address these challenges.

  4. Movement of particles using sequentially activated dielectrophoretic particle trapping

    DOEpatents

    Miles, Robin R.

    2004-02-03

    Manipulation of DNA and cells/spores using dielectrophoretic (DEP) forces to perform sample preparation protocols for polymerized chain reaction (PCR) based assays for various applications. This is accomplished by movement of particles using sequentially activated dielectrophoretic particle trapping. DEP forces induce a dipole in particles, and these particles can be trapped in non-uniform fields. The particles can be trapped in the high field strength region of one set of electrodes. By switching off this field and switching on an adjacent electrodes, particles can be moved down a channel with little or no flow.

  5. Dreamed movement elicits activation in the sensorimotor cortex.

    PubMed

    Dresler, Martin; Koch, Stefan P; Wehrle, Renate; Spoormaker, Victor I; Holsboer, Florian; Steiger, Axel; Sämann, Philipp G; Obrig, Hellmuth; Czisch, Michael

    2011-11-01

    Since the discovery of the close association between rapid eye movement (REM) sleep and dreaming, much effort has been devoted to link physiological signatures of REM sleep to the contents of associated dreams [1-4]. Due to the impossibility of experimentally controlling spontaneous dream activity, however, a direct demonstration of dream contents by neuroimaging methods is lacking. By combining brain imaging with polysomnography and exploiting the state of "lucid dreaming," we show here that a predefined motor task performed during dreaming elicits neuronal activation in the sensorimotor cortex. In lucid dreams, the subject is aware of the dreaming state and capable of performing predefined actions while all standard polysomnographic criteria of REM sleep are fulfilled [5, 6]. Using eye signals as temporal markers, neural activity measured by functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS) was related to dreamed hand movements during lucid REM sleep. Though preliminary, we provide first evidence that specific contents of REM-associated dreaming can be visualized by neuroimaging. PMID:22036177

  6. Cardiovascular responses to active and passive cycling movements.

    PubMed

    Nóbrega, A C; Williamson, J W; Friedman, D B; Araújo, C G; Mitchell, J H

    1994-06-01

    Ten healthy subjects were evaluated at rest and at 5 min of unloaded active (AC) and passive (PC) cycling. Passive limb movements were accomplished using a tandem bicycle with a second rider performing the movements. We measured heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), oxygen uptake (VO2), rating of perceived exertion (RPE), and electrical activity (EMG) of lower limbs muscles. Values for stroke volume (SV) and peripheral vascular resistance (PVR) were calculated. EMG, RPE, and VO2 were higher during AC than during PC (P < 0.001). CO increased during both modes of cycling, but during AC it resulted from a HR acceleration (73 +/- 2 at rest to 82 +/- 2 beats.min-1 at 60 rpm; P < 0.001) with no change in SV whereas during PC, SV increased from rest (65 +/- 4 at rest to 71 +/- 3 ml at 60 rpm; P = 0.003) along with no change in HR. PVR remained constant during PC, but decreased by 13% during AC (P < 0.001) and MAP increased only during PC (93 +/- 2 at rest to 107 +/- 2 mm Hg at 60 rpm). These results supports the concept that central command determines the HR response to dynamic exercise. The increase in SV and consequently in MAP during PC was probably due to increased venous return and/or to muscle mechanoreceptor-evoked increased myocardial contractility. PMID:8052111

  7. Improved orthopedic arm joint

    NASA Technical Reports Server (NTRS)

    Dane, D. H.

    1971-01-01

    Joint permits smooth and easy movement of disabled arm and is smaller, lighter and less expensive than previous models. Device is interchangeable and may be used on either arm at the shoulder or at the elbow.

  8. Loss, adaptation and new directions: The impact of arm morbidity on leisure activities following breast cancer.

    PubMed

    Thomas, Roanne; Hack, Thomas F; Quinlan, Elizabeth; Tatemichi, Sue; Towers, Anna; Kwan, Winkle; Miedema, Baukje; Tilley, Andrea; Hamoline, Rita; Morrison, Tricia

    2015-01-01

    The impact of arm morbidity on leisure and quality of life is an understudied area in cancer survivorship. The purpose of this study was to qualitatively describe the impact of breast cancer-related arm morbidity on leisure participation in Canadian women. A grounded theory approach was used to generate thematic categories and a model. Drawing on participants from a larger cohort study (n = 740), 40 women with arm morbidity symptoms were purposively sampled and interviewed. Three themes emerged: a sense of loss, adapting participation, and new directions. Women with arm morbidity may experience an abrupt loss of previously enjoyed leisure activities and engage in a process of adapting to discover new meanings and directions. Comprehensive, person-centred cancer survivorship programs may assist with adaptation to arm morbidity. PMID:26642494

  9. Eye movements and hazard perception in active and passive driving

    PubMed Central

    Mackenzie, Andrew K.; Harris, Julie M.

    2015-01-01

    ABSTRACT Differences in eye movement patterns are often found when comparing passive viewing paradigms to actively engaging in everyday tasks. Arguably, investigations into visuomotor control should therefore be most useful when conducted in settings that incorporate the intrinsic link between vision and action. We present a study that compares oculomotor behaviour and hazard reaction times across a simulated driving task and a comparable, but passive, video-based hazard perception task. We found that participants scanned the road less during the active driving task and fixated closer to the front of the vehicle. Participants were also slower to detect the hazards in the driving task. Our results suggest that the interactivity of simulated driving places increased demand upon the visual and attention systems than simply viewing driving movies. We offer insights into why these differences occur and explore the possible implications of such findings within the wider context of driver training and assessment. PMID:26681913

  10. A dynamic model for generating actuator specifications for small arms barrel active stabilization

    NASA Astrophysics Data System (ADS)

    Pathak, Anupam; Brei, Diann; Luntz, Jonathan; Lavigna, Chris

    2006-03-01

    Due to stresses encountered in combat, it is known that soldier marksmanship noticeably decreases regardless of prior training. Active stabilization systems in small arms have potential to address this problem to increase soldier survivability and mission effectiveness. The key to success is proper actuator design, but this is highly dependent on proper specification which is challenging due to the human/weapon interaction. This paper presents a generic analytical dynamic model which is capable of defining the necessary actuation specifications for a wide range of small arms platforms. The model is unique because it captures the human interface--shoulder and arm--that introduces the jitter disturbance in addition to the geometry, inertial properties and active stabilization stiffness of the small arms platform. Because no data to date is available for actual shooter-induced disturbance in field conditions, a method is given using the model to back-solve from measured shooting range variability data the disturbance amplitude information relative to the input source (arm or shoulder). As examples of the applicability of the model to various small arms systems, two different weapon systems were investigated: the M24 sniper weapon and the M16 assault rifle. In both cases, model based simulations provided valuable insight into impact on the actuation specifications (force, displacement, phase, frequency) due to the interplay of the human-weapon-active stabilization interface including the effect of shooter-disturbance frequency, disturbance location (shoulder vs. arm), and system parameters (stiffness, barrel rotation).

  11. Making music after stroke: using musical activities to enhance arm function.

    PubMed

    van Wijck, Frederike; Knox, Don; Dodds, Colin; Cassidy, Gianna; Alexander, Gillian; MacDonald, Raymond

    2012-04-01

    A common long-term consequence of stroke is impaired arm function, which affects independence and quality of life in a considerable proportion of stroke survivors. There is a growing need for self-management strategies that enable stroke survivors to continue their recovery after rehabilitation has ceased. Interventions with high-intensity, repetitive task training and feedback are most likely to improve function. Achieving the required amount of self-practice is challenging, however. Innovative approaches are required to translate therapies into rewarding activities that can be undertaken independently. This paper describes the key principles and development of a novel intervention that integrates individuals' preferred music with game technology in upper limb rehabilitation. The "tap tempo" paradigm, which uses rhythmic auditory cueing, provides repetitive upper limb task training, which can be tailored to individual goals and progress (e.g., in terms of movement range and complexity), while providing sensitive quantitative feedback to promote skill acquisition and enhance self-management. PMID:22524372

  12. Modulation of event-related desynchronization in robot-assisted hand performance: brain oscillatory changes in active, passive and imagined movements

    PubMed Central

    2013-01-01

    Background Robot-assisted therapy in patients with neurological disease is an attempt to improve function in a moderate to severe hemiparetic arm. A better understanding of cortical modifications after robot-assisted training could aid in refining rehabilitation therapy protocols for stroke patients. Modifications of cortical activity in healthy subjects were evaluated during voluntary active movement, passive robot-assisted motor movement, and motor imagery tasks performed under unimanual and bimanual protocols. Methods Twenty-one channel electroencephalography (EEG) was recorded with a video EEG system in 8 subjects. The subjects performed robot-assisted tasks using the Bi-Manu Track robot-assisted arm trainer. The motor paradigm was executed during one-day experimental sessions under eleven unimanual and bimanual protocols of active, passive and imaged movements. The event-related-synchronization/desynchronization (ERS/ERD) approach to the EEG data was applied to investigate where movement-related decreases in alpha and beta power were localized. Results Voluntary active unilateral hand movement was observed to significantly activate the contralateral side; however, bilateral activation was noted in all subjects on both the unilateral and bilateral active tasks, as well as desynchronization of alpha and beta brain oscillations during the passive robot-assisted motor tasks. During active-passive movement when the right hand drove the left one, there was predominant activation in the contralateral side. Conversely, when the left hand drove the right one, activation was bilateral, especially in the alpha range. Finally, significant contralateral EEG desynchronization was observed during the unilateral task and bilateral ERD during the bimanual task. Conclusions This study suggests new perspectives for the assessment of patients with neurological disease. The findings may be relevant for defining a baseline for future studies investigating the neural correlates of

  13. Structure of urban movements: polycentric activity and entangled hierarchical flows.

    PubMed

    Roth, Camille; Kang, Soong Moon; Batty, Michael; Barthélemy, Marc

    2011-01-01

    The spatial arrangement of urban hubs and centers and how individuals interact with these centers is a crucial problem with many applications ranging from urban planning to epidemiology. We utilize here in an unprecedented manner the large scale, real-time 'Oyster' card database of individual person movements in the London subway to reveal the structure and organization of the city. We show that patterns of intraurban movement are strongly heterogeneous in terms of volume, but not in terms of distance travelled, and that there is a polycentric structure composed of large flows organized around a limited number of activity centers. For smaller flows, the pattern of connections becomes richer and more complex and is not strictly hierarchical since it mixes different levels consisting of different orders of magnitude. This new understanding can shed light on the impact of new urban projects on the evolution of the polycentric configuration of a city and the dense structure of its centers and it provides an initial approach to modeling flows in an urban system. PMID:21249210

  14. Structure of Urban Movements: Polycentric Activity and Entangled Hierarchical Flows

    PubMed Central

    Roth, Camille; Kang, Soong Moon; Batty, Michael; Barthélemy, Marc

    2011-01-01

    The spatial arrangement of urban hubs and centers and how individuals interact with these centers is a crucial problem with many applications ranging from urban planning to epidemiology. We utilize here in an unprecedented manner the large scale, real-time ‘Oyster’ card database of individual person movements in the London subway to reveal the structure and organization of the city. We show that patterns of intraurban movement are strongly heterogeneous in terms of volume, but not in terms of distance travelled, and that there is a polycentric structure composed of large flows organized around a limited number of activity centers. For smaller flows, the pattern of connections becomes richer and more complex and is not strictly hierarchical since it mixes different levels consisting of different orders of magnitude. This new understanding can shed light on the impact of new urban projects on the evolution of the polycentric configuration of a city and the dense structure of its centers and it provides an initial approach to modeling flows in an urban system. PMID:21249210

  15. Cortical Spiking Network Interfaced with Virtual Musculoskeletal Arm and Robotic Arm

    PubMed Central

    Dura-Bernal, Salvador; Zhou, Xianlian; Neymotin, Samuel A.; Przekwas, Andrzej; Francis, Joseph T.; Lytton, William W.

    2015-01-01

    Embedding computational models in the physical world is a critical step towards constraining their behavior and building practical applications. Here we aim to drive a realistic musculoskeletal arm model using a biomimetic cortical spiking model, and make a robot arm reproduce the same trajectories in real time. Our cortical model consisted of a 3-layered cortex, composed of several hundred spiking model-neurons, which display physiologically realistic dynamics. We interconnected the cortical model to a two-joint musculoskeletal model of a human arm, with realistic anatomical and biomechanical properties. The virtual arm received muscle excitations from the neuronal model, and fed back proprioceptive information, forming a closed-loop system. The cortical model was trained using spike timing-dependent reinforcement learning to drive the virtual arm in a 2D reaching task. Limb position was used to simultaneously control a robot arm using an improved network interface. Virtual arm muscle activations responded to motoneuron firing rates, with virtual arm muscles lengths encoded via population coding in the proprioceptive population. After training, the virtual arm performed reaching movements which were smoother and more realistic than those obtained using a simplistic arm model. This system provided access to both spiking network properties and to arm biophysical properties, including muscle forces. The use of a musculoskeletal virtual arm and the improved control system allowed the robot arm to perform movements which were smoother than those reported in our previous paper using a simplistic arm. This work provides a novel approach consisting of bidirectionally connecting a cortical model to a realistic virtual arm, and using the system output to drive a robotic arm in real time. Our techniques are applicable to the future development of brain neuroprosthetic control systems, and may enable enhanced brain-machine interfaces with the possibility for finer control of

  16. Cortical Spiking Network Interfaced with Virtual Musculoskeletal Arm and Robotic Arm.

    PubMed

    Dura-Bernal, Salvador; Zhou, Xianlian; Neymotin, Samuel A; Przekwas, Andrzej; Francis, Joseph T; Lytton, William W

    2015-01-01

    Embedding computational models in the physical world is a critical step towards constraining their behavior and building practical applications. Here we aim to drive a realistic musculoskeletal arm model using a biomimetic cortical spiking model, and make a robot arm reproduce the same trajectories in real time. Our cortical model consisted of a 3-layered cortex, composed of several hundred spiking model-neurons, which display physiologically realistic dynamics. We interconnected the cortical model to a two-joint musculoskeletal model of a human arm, with realistic anatomical and biomechanical properties. The virtual arm received muscle excitations from the neuronal model, and fed back proprioceptive information, forming a closed-loop system. The cortical model was trained using spike timing-dependent reinforcement learning to drive the virtual arm in a 2D reaching task. Limb position was used to simultaneously control a robot arm using an improved network interface. Virtual arm muscle activations responded to motoneuron firing rates, with virtual arm muscles lengths encoded via population coding in the proprioceptive population. After training, the virtual arm performed reaching movements which were smoother and more realistic than those obtained using a simplistic arm model. This system provided access to both spiking network properties and to arm biophysical properties, including muscle forces. The use of a musculoskeletal virtual arm and the improved control system allowed the robot arm to perform movements which were smoother than those reported in our previous paper using a simplistic arm. This work provides a novel approach consisting of bidirectionally connecting a cortical model to a realistic virtual arm, and using the system output to drive a robotic arm in real time. Our techniques are applicable to the future development of brain neuroprosthetic control systems, and may enable enhanced brain-machine interfaces with the possibility for finer control of

  17. Impact of maternal physical activity on fetal breathing and body movement--A review.

    PubMed

    Sussman, Dafna; Lye, Stephen J; Wells, Greg D

    2016-03-01

    Fetal movements, which include body and breathing movement, are important indicators of fetal well-being and nervous system development. These have been shown to be affected by intrauterine conditions. While maternal physical activity does induce a change in intrauterine conditions and physiology, its impact on fetal movements is still unclear. This paper will provide a brief review of the literature and outline the current knowledge with regards to the effects of maternal exercise on fetal body and breathing movements. PMID:26811196

  18. Muscular Activity in the Arm during Lexical Retrieval: Implications for Gesture-Speech Theories

    ERIC Educational Resources Information Center

    Morsella, Ezequiel; Krauss, Robert M.

    2005-01-01

    The origin and functions of the hand and arm gestures that accompany speech production are poorly understood. It has been proposed that gestures facilitate lexical retrieval, but little is known about when retrieval is accompanied by gestural activity and how this activity is related to the semantics of the word to be retrieved. Electromyographic…

  19. Endurance time, muscular activity and the hand/arm tremor for different exertion forces of holding.

    PubMed

    Lee, Tzu-Hsien

    2016-01-01

    This study aimed to examine the effects of exertion force on endurance time, muscular activity and hand/arm tremor during holding. Fifteen healthy young males were recruited as participants. The independent variable was exertion force (20%, 40%, 60% and 80% maximum holding capacity). The dependent variables were endurance time, muscular activity and hand/arm tremor. The results showed that endurance time decreased with exertion force while muscular activity and hand/arm tremor increased with exertion force. Hand/arm tremor increased with holding time. Endurance time of 40%, 60% and 80% maximum holding capacity was approximately 22.7%, 12.0% and 5.6% of that of 20% maximum holding capacity, respectively. The rms (root mean square) acceleration of hand/arm tremor of the final phase of holding was 2.27-, 1.33-, 1.20- and 1.73-fold of that of the initial phase of holding for 20%, 40%, 60% and 80% maximum holding capacity, respectively. PMID:26655224

  20. Movement of Sediment Associated With Lowered Reservoir Levels in the Rio La Venta Arm of the Presa Netzahualcoyotl, Chiapas, Mexico

    NASA Astrophysics Data System (ADS)

    Hilton, S.; de La Fuente, J.; Lisle, T. E.; Velasquez, J.; Allison, B.; Olson, B.; Quinones, R.

    2003-12-01

    A joint sedimentation study is currently underway at the Netzahualcoyotl reservoir in Chiapas, Mexico, involving the Comision Nacional de Areas Naturales Protegidas (CONANP) of the Secretaria de Medio Ambiente y Recursos Naturales and the USDA Forest Service. The reservoir is adjacent to the Reserva de la Biosfera, Selva El Ocote, administered by CONANP. Ongoing research is intended to provide watershed and reservoir managers with strategies to protect the resources of Rio La Venta canyon. The Rio La Venta arm of the reservoir is incised into karst terrain, with near-vertical limestone walls up to 300 meters high. The canyon is fed by two rivers, Rio La Selva and Rio Negro, and is surrounded by pristine tropical forest. The majority of the clastic sediment (predominantly sand and fine gravel) entering the reservoir originates in the headwaters of the two rivers which are underlain by weathered and dissected granitic terrain. Rapid sedimentation of the partially inundated canyon poses a threat to the aquatic ecosystem, as well as to recreational resources. Longitudinal and transverse profiles were surveyed in the inundated canyon in March of 2002 and repeated in April of 2003 when the reservoir level was 15 meters lower. The 2002 longitudinal profile shows an inflection from a slope of 0.0017 to one of 0.0075 at 7.2 km downstream of the mouth of Rio Negro. In 2003, the two slopes remained the same, but the bed lowered about 5 meters and the inflection point moved downstream about 2.3 km. We calculated that reservoir lowering in 2003 allowed the transport of 2.5 million cubic meters of sand further out into the reservoir. This volume is more than the average annual rate of filling up to the 2002 level since 1984 when sedimentation was not as advanced (De la Fuente et al., 2002), which was calculated disregarding loss of sediment to the main reservoir. Field observations at late dry season low flows in 2003 revealed active transport of sand and pebbles and formation

  1. The Arm of the School that Extends into the Homes: The Visiting Teacher Movement, 1906-1940.

    ERIC Educational Resources Information Center

    Knupfer, Anne Meis

    1999-01-01

    Describes the rise of the visiting teacher movement from 1906 to 1940, examining the sources of early visiting teacher work, discussing the origins of visiting teachers' work, noting medical and psychiatric discourses surrounding visiting teachers' work, describing the influence on preservice teacher-education programs, and considering the lessons…

  2. Right-Left Approach and Reaching Arm Movements of 4-Month Infants in Free and Constrained Conditions

    ERIC Educational Resources Information Center

    Morange-Majoux, Francoise; Dellatolas, Georges

    2010-01-01

    Recent theories on the evolution of language (e.g. Corballis, 2009) emphazise the interest of early manifestations of manual laterality and manual specialization in human infants. In the present study, left- and right-hand movements towards a midline object were observed in 24 infants aged 4 months in a constrained condition, in which the hands…

  3. Sensory processing in the vestibular nuclei during active head movements

    NASA Technical Reports Server (NTRS)

    Gdowski, G. T.; Boyle, R.; McCrea, R. A.; Peterson, B. W. (Principal Investigator)

    2000-01-01

    Many secondary vestibular neurons are sensitive to head on trunk rotation during reflex-induced and voluntary head movements. During passive whole body rotation the interaction of head on trunk signals related to the vestibulo-collic reflex with vestibular signals increases the rotational gain of many secondary vestibular neurons, including many that project to the spinal cord. In some units, the sensitivity to head on trunk and vestibular input is matched and the resulting interaction produces an output that is related to the trunk velocity in space. In other units the head on trunk inputs are stronger and the resulting interaction produces an output that is larger during the reflex. During voluntary head movements, inputs related to head on trunk movement combine destructively with vestibular signals, and often cancel the sensory reafferent consequences of self-generated movements. Cancellation of sensory vestibular signals was observed in all of the antidromically identified secondary vestibulospinal units, even though many of these units were not significantly affected by reflexive head on trunk movements. The results imply that the inputs to vestibular neurons related to head on trunk rotation during reflexive and voluntary movements arise from different sources. We suggest that the relative strength of reflexive head on trunk input to different vestibular neurons might reflect the different functional roles they have in controlling the posture of the neck and body.

  4. Brain activation during ideomotor praxis: imitation and movements executed by verbal command

    PubMed Central

    Makuuchi, M; Kaminaga, T; Sugishita, M

    2005-01-01

    Background: Ideomotor apraxia is a disorder of both imitation movements and movements executed by verbal command. Lesion studies have identified the left parietal lobe as the neural correlate for ideomotor praxis (IP), although there are opposing views. Objectives: To localise the neural substrates for IP using functional magnetic resonance imaging. Brain regions activated by both imitation and verbal command movements were tested against a simple self paced movement. Methods: Twenty two young, right handed, healthy subjects were examined. Functional and anatomical data were acquired. The experiment comprised three motor conditions (imitation, movements executed by verbal command, and finger bending/unbending) and a rest condition. All motor tasks were performed using the left hand. Eighteen drawings of left hand postures were presented for the imitation condition. Identical postures were instructed verbally for the verbal command condition. The finger bending/unbending movement was self paced. Blood oxygenation level dependent (BOLD) signal increases were compared during two kinds of IP (imitation and verbal command movements) and during finger bending/unbending movements. Results: The depth of the posterior part of the left intraparietal sulcus and bilateral precunei were activated during both imitation and verbal command movements. The difference in BOLD signal between imitation and verbal command movements was localised in the dorsal and ventral occipital areas. BOLD signal differences for movements executed by verbal command against imitation were observed in the superior temporal areas. Conclusions: The depth of the posterior part of the left intraparietal sulcus and bilateral precunei are the neural substrates for IP. PMID:15607991

  5. Adolescents' Perception of the Relationship between Movement Skills, Physical Activity and Sport

    ERIC Educational Resources Information Center

    Barnett, Lisa; Cliff, Ken; Morgan, Philip; van Beurden, Eric

    2013-01-01

    Movement skill competence is important to organised youth physical activity participation, but it is unclear how adolescents view this relationship. The primary aim of this study was to explore adolescents' perception of the relationship between movement skills, physical activity and sport, and whether their perceptions differed according to…

  6. Movement Actors in the Education Bureaucracy: The Figured World of Activity Based Learning in Tamil Nadu

    ERIC Educational Resources Information Center

    Niesz, Tricia; Krishnamurthy, Ramchandar

    2014-01-01

    Tamil Nadu has gained international recognition for reforming its government school classrooms into active, child-centered learning environments. Our exploration of the history of the Activity Based Learning movement suggests that this reform was achieved by social movement actors serving in and through the state's administration.…

  7. Moving to Music: Effects of Heard and Imagined Musical Cues on Movement-Related Brain Activity

    PubMed Central

    Schaefer, Rebecca S.; Morcom, Alexa M.; Roberts, Neil; Overy, Katie

    2014-01-01

    Music is commonly used to facilitate or support movement, and increasingly used in movement rehabilitation. Additionally, there is some evidence to suggest that music imagery, which is reported to lead to brain signatures similar to music perception, may also assist movement. However, it is not yet known whether either imagined or musical cueing changes the way in which the motor system of the human brain is activated during simple movements. Here, functional magnetic resonance imaging was used to compare neural activity during wrist flexions performed to either heard or imagined music with self-pacing of the same movement without any cueing. Focusing specifically on the motor network of the brain, analyses were performed within a mask of BA4, BA6, the basal ganglia (putamen, caudate, and pallidum), the motor nuclei of the thalamus, and the whole cerebellum. Results revealed that moving to music compared with self-paced movement resulted in significantly increased activation in left cerebellum VI. Moving to imagined music led to significantly more activation in pre-supplementary motor area (pre-SMA) and right globus pallidus, relative to self-paced movement. When the music and imagery cueing conditions were contrasted directly, movements in the music condition showed significantly more activity in left hemisphere cerebellum VII and right hemisphere and vermis of cerebellum IX, while the imagery condition revealed more significant activity in pre-SMA. These results suggest that cueing movement with actual or imagined music impacts upon engagement of motor network regions during the movement, and suggest that heard and imagined cues can modulate movement in subtly different ways. These results may have implications for the applicability of auditory cueing in movement rehabilitation for different patient populations. PMID:25309407

  8. Moving to music: effects of heard and imagined musical cues on movement-related brain activity.

    PubMed

    Schaefer, Rebecca S; Morcom, Alexa M; Roberts, Neil; Overy, Katie

    2014-01-01

    Music is commonly used to facilitate or support movement, and increasingly used in movement rehabilitation. Additionally, there is some evidence to suggest that music imagery, which is reported to lead to brain signatures similar to music perception, may also assist movement. However, it is not yet known whether either imagined or musical cueing changes the way in which the motor system of the human brain is activated during simple movements. Here, functional magnetic resonance imaging was used to compare neural activity during wrist flexions performed to either heard or imagined music with self-pacing of the same movement without any cueing. Focusing specifically on the motor network of the brain, analyses were performed within a mask of BA4, BA6, the basal ganglia (putamen, caudate, and pallidum), the motor nuclei of the thalamus, and the whole cerebellum. Results revealed that moving to music compared with self-paced movement resulted in significantly increased activation in left cerebellum VI. Moving to imagined music led to significantly more activation in pre-supplementary motor area (pre-SMA) and right globus pallidus, relative to self-paced movement. When the music and imagery cueing conditions were contrasted directly, movements in the music condition showed significantly more activity in left hemisphere cerebellum VII and right hemisphere and vermis of cerebellum IX, while the imagery condition revealed more significant activity in pre-SMA. These results suggest that cueing movement with actual or imagined music impacts upon engagement of motor network regions during the movement, and suggest that heard and imagined cues can modulate movement in subtly different ways. These results may have implications for the applicability of auditory cueing in movement rehabilitation for different patient populations. PMID:25309407

  9. Turnip vein clearing virus movement protein nuclear activity: Do Tobamovirus movement proteins play a role in immune response suppression?

    PubMed Central

    Levy, Amit

    2015-01-01

    Plant viruses' cell-to-cell movement requires the function of virally encoded movement proteins (MPs). The Tobamovirus, Tobacco mosaic virus (TMV) has served as the model virus to study the activities of single MPs. However, since TMV does not infect the model plant Arabidopsis thaliana I have used a related Tobamovirus, Turnip vein-clearing virus (TVCV). I recently showed that, despite belonging to the same genus, the behavior of the 2 viruses MPs differ significantly during infection. Most notably, MPTVCV, but not MPTMV, targets the nucleus and induces the formation of F actin-containing filaments that associate with chromatin. Mutational analyses showed that nuclear localization of MPTVCV was necessary for TVCV local and systemic infection in both Nicotiana benthamiana and Arabidopsis. In this addendum, I propose possible targets for the MPTVCV nuclear activity, and suggest viewing MPs as viral effector-like proteins, playing a role in the inhibition of plant defense. PMID:26237173

  10. An Exploratory Investigation on the Use of Closed-Loop Electrical Stimulation to Assist Individuals with Stroke to Perform Fine Movements with Their Hemiparetic Arm

    PubMed Central

    Lew, Brian; Alavi, Nezam; Randhawa, Bubblepreet K.; Menon, Carlo

    2016-01-01

    Stroke is the leading cause of upper limb impairments resulting in disability. Modern rehabilitation includes training with robotic exoskeletons and functional electrical stimulation (FES). However, there is a gap in knowledge to define the detailed use of FES in stroke rehabilitation. In this paper, we explore applying closed-loop FES to the upper extremities of healthy volunteers and individuals with a hemiparetic arm resulting from stroke. We used a set of gyroscopes to monitor arm movements and used a non-linear controller, namely, the robust integral of the sign of the error (RISE), to assess the viability of controlling FES in closed loop. Further, we explored the application of closed-loop FES in improving functional tasks performed by individuals with stroke. Four healthy individuals of ages 27–32 years old and five individuals with stroke of ages 61–83 years old participated in this study. We used the Rehastim FES unit (Hasomed Ltd.) with real-time modulation of pulse width and amplitude. Both healthy and stroke individuals were tested in RISE-controlled single and multi-joint upper limb motions following first a sinusoidal trajectory. Individuals with stroke were also asked to perform the following functional tasks: picking up a basket, picking and placing an object on a table, cutting a pizza, pulling back a chair, eating with a spoon, as well as using a stapler and grasping a pen. Healthy individuals were instructed to keep their arm relaxed during the experiment. Most individuals with stroke were able to follow the sinusoid trajectories with their arm joints under the sole excitation of the closed-loop-controlled FES. One individual with stroke, who was unable to perform any of the functional tasks independently, succeeded in completing all the tasks when FES was used. Three other individuals with stroke, who were unable to complete a few tasks independently, completed some of them when FES was used. The remaining stroke participant was able to

  11. An Exploratory Investigation on the Use of Closed-Loop Electrical Stimulation to Assist Individuals with Stroke to Perform Fine Movements with Their Hemiparetic Arm.

    PubMed

    Lew, Brian; Alavi, Nezam; Randhawa, Bubblepreet K; Menon, Carlo

    2016-01-01

    Stroke is the leading cause of upper limb impairments resulting in disability. Modern rehabilitation includes training with robotic exoskeletons and functional electrical stimulation (FES). However, there is a gap in knowledge to define the detailed use of FES in stroke rehabilitation. In this paper, we explore applying closed-loop FES to the upper extremities of healthy volunteers and individuals with a hemiparetic arm resulting from stroke. We used a set of gyroscopes to monitor arm movements and used a non-linear controller, namely, the robust integral of the sign of the error (RISE), to assess the viability of controlling FES in closed loop. Further, we explored the application of closed-loop FES in improving functional tasks performed by individuals with stroke. Four healthy individuals of ages 27-32 years old and five individuals with stroke of ages 61-83 years old participated in this study. We used the Rehastim FES unit (Hasomed Ltd.) with real-time modulation of pulse width and amplitude. Both healthy and stroke individuals were tested in RISE-controlled single and multi-joint upper limb motions following first a sinusoidal trajectory. Individuals with stroke were also asked to perform the following functional tasks: picking up a basket, picking and placing an object on a table, cutting a pizza, pulling back a chair, eating with a spoon, as well as using a stapler and grasping a pen. Healthy individuals were instructed to keep their arm relaxed during the experiment. Most individuals with stroke were able to follow the sinusoid trajectories with their arm joints under the sole excitation of the closed-loop-controlled FES. One individual with stroke, who was unable to perform any of the functional tasks independently, succeeded in completing all the tasks when FES was used. Three other individuals with stroke, who were unable to complete a few tasks independently, completed some of them when FES was used. The remaining stroke participant was able to

  12. Event-Related Beta EEG Changes During Active, Passive Movement and Functional Electrical Stimulation of the Lower Limb.

    PubMed

    Qiu, Shuang; Yi, Weibo; Xu, Jiapeng; Qi, Hongzhi; Du, Jingang; Wang, Chunfang; He, Feng; Ming, Dong

    2016-02-01

    A number of electroencephalographic (EEG) studies have reported on event-related desynchronization/synchronization (ERD/ERS) during active movements, passive movements, and the movements induced by functional electrical stimulation (FES). However, the quantitative differences in ERD values and affected frequency bands associated with the lower limb have not been discussed. The goal of this paper was to quantitatively compare the ERD patterns during active movement, passive movement and FES-induced movement of the lower limb. 64-channel EEG signals were recorded to investigate the brain oscillatory patterns during active movement, passive movement and FES-induced movement of the lower limb in twelve healthy subjects. And passive movement and FES-induced movement were also performed in a hemiplegic stroke patient. For healthy subjects, FES-induced movement presented significantly higher characteristic frequency of central beta ERD while there was no significant difference in ERD values compared with active or passive movement. Meanwhile, beta ERD values of FES-induced movement were significantly correlated with those of active movement, and spatial distribution of beta ERD pattern for FES-induced movement was more correlated with that for active movement. In addition, the stroke patient presented central ERD patterns during FES-induced movement, while no ERD with similar frequencies could be found during passive movement. This work implies that the EEG oscillatory pattern under FES-induced movement tends more towards active movement instead of passive movement. The quantification of ERD patterns could be expected as a potential technique to evaluate the brain response during FES-induced movement. PMID:26441422

  13. Fusimotor influence on jaw muscle spindle activity during swallowing-related movements in the cat.

    PubMed Central

    Taylor, A; Hidaka, O; Durbaba, R; Ellaway, P H

    1997-01-01

    1. The activity patterns of muscle spindle afferents in jaw-closer muscles were studied during reflex swallowing movements in anaesthetized cats. Simultaneous records were made of the electromyogram (EMG) in masseter and anterior digastric muscles and of the unloaded jaw movements. The underlying patterns of fusimotor activity were deduced by comparing afferent discharges occurring during active swallowing with those occurring when exactly the same movements were imposed passively. The interpretation of spindle behaviour was greatly facilitated by characterizing the afferents according to the evidence for their contact with the various intrafusal muscle fibres, derived from testing with succinylcholine. It was also valuable to have two different types of afferent recorded simultaneously. 2. There was clear evidence of fusimotor activity occurring during active jaw closing so as to oppose the spindle silencing. This effect was most marked in b2c-type afferents (probably secondaries) and was therefore attributed to a modulation of static fusimotor discharge approximately in parallel with alpha-activity. 3. Afferents with evidence of bag1 fibre contacts (primaries) showed much greater sensitivity to muscle lengthening during active movement than when the movement was imposed. This difference was exaggerated when anaesthesia was deepened for the passive movements. This was interpreted as evidence for a higher level of dynamic fusimotor activity maintained during active movements than at rest. 4. The results support the view that for a variety of active jaw movements, static fusimotor neurone firing is modulated roughly in parallel with alpha-activity but leading it so as to counteract spindle unloading. Dynamic fusimotor neurone firing appears to be set at a raised level during active movements. Anaesthesia appears to depress activity in the alpha-motoneurones more than in gamma-motoneurones. PMID:9288683

  14. Active route learning in virtual environments: disentangling movement control from intention, instruction specificity, and navigation control.

    PubMed

    von Stülpnagel, Rul; Steffens, Melanie C

    2013-09-01

    Active navigation research examines how physiological and psychological involvement in navigation benefits spatial learning. However, existing conceptualizations of active navigation comprise separable, distinct factors. This research disentangles the contributions of movement control (i.e., self-contained vs. observed movement) as a central factor from learning intention (Experiment 1), instruction specificity and instruction control (Experiment 2), as well as navigation control (Experiment 3) to spatial learning in virtual environments. We tested the effects of these factors on landmark recognition (landmark knowledge), tour-integration and route navigation (route knowledge). Our findings suggest that movement control leads to robust advantages in landmark knowledge as compared to observed movement. Advantages in route knowledge do not depend on learning intention, but on the need to elaborate spatial information. Whenever the necessary level of elaboration is assured for observed movement, too, the development of route knowledge is not inferior to that for self-contained movement. PMID:22922991

  15. Evolution of the environmental justice movement: activism, formalization and differentiation

    NASA Astrophysics Data System (ADS)

    Colsa Perez, Alejandro; Grafton, Bernadette; Mohai, Paul; Hardin, Rebecca; Hintzen, Katy; Orvis, Sara

    2015-10-01

    To complement a recent flush of research on transnational environmental justice movements, we sought a deeper organizational history of what we understand as the contemporary environmental justice movement in the United States. We thus conducted in-depth interviews with 31 prominent environmental justice activists, scholars, and community leaders across the US. Today’s environmental justice groups have transitioned from specific local efforts to broader national and global mandates, and more sophisticated political, technological, and activist strategies. One of the most significant transformations has been the number of groups adopting formal legal status, and emerging as registered environmental justice organizations (REJOs) within complex partnerships. This article focuses on the emergence of REJOs, and describes the respondents’ views about the implications of this for more local grassroots groups. It reveals a central irony animating work across groups in today’s movement: legal formalization of many environmental justice organizations has made the movement increasingly internally differentiated, dynamic, and networked, even as the passage of actual national laws on environmental justice has proven elusive.

  16. Summary of the ARM activities at ECMWF from 2007-2009

    SciTech Connect

    Maike Ahlgrimm; Anton Beljaars

    2010-07-13

    The European Centre for Medium-Range Weather Forecasts (ECMWF), as one of the leading centres in numerical weather prediction, has been an active user of observations for model evaluation for many years. Many examples exist where detailed experimental studies have inspired model improvement. To establish a link between the Atmospheric Radiation Measurement (ARM) research and ECMWF's model development, funding was provided for an \\u201cARM fellow\\u201d at ECMWF. Furthermore, ECMWF has been working closely with ARM related projects for many years. ECMWF provides operational analysis data for the ARM stations (permanent and mobile) as background meteorological information and ECMWF has implemented the Rapid Radiative Transport Model long wave and short wave schemes as radiation codes in the operational system. These codes were developed at Atmospheric and Environmental Research Inc. with ARM support and were extensively evaluated using detailed ARM observations. This short report describes the history of the ARM-fellowship at ECMWF and summarizes the achievements over the last 3 years. The emphasis of the ARM funded work over the last 3 years has been on further development and evaluation of a new shallow convection scheme in the context of ECMWF's Numerical Weather Prediction (NWP) system. The shallow convection scheme is based on the DualM approach which combines Eddy Diffusion with a Dual Mass flux concept. One of the mass fluxes describes the dry updraughts, whereas the second updraught saturates at cloud base and penetrates into the cloud. The new scheme was optimized using single column cases from a wide range of climatological regimes. Further evaluation of the 3-dimensional model using Lidar data from space (CALIPSO) clearly indicates that the resulting cloud structures are much more realistic than the ones produced by the control model (Tiedtke mass flux scheme). Additionally, data from the ARM mobile facility in 2006 in Niamey has been used to evaluate the

  17. Physical Activity and Movement Proficiency: The Need for a Biocultural Approach.

    PubMed

    Malina, Robert M; Cumming, Sean P; Coelho E Silva, Manuel J

    2016-05-01

    "Gaps in Our Knowledge" are discussed in the context of the need to integrate biological and behavioral factors in a biocultural approach to physical activity and movement proficiency. Specific issues considered include outdoor play, organized and informal activity, biological maturation, tracking of activity, development of movement proficiency, and individual differences. Studies considered are largely based on youth in economically better-off, developed countries in the western culture context. There is a need to extend studies of physical activity and movement proficiency to different cultural contexts. PMID:27137170

  18. Human movements and abstract motion displays activate different processes in the observer's motor system.

    PubMed

    Agosta, Sara; Battelli, Lorella; Casile, Antonino

    2016-04-15

    Brain imaging studies have shown that observation of both bodily movements and abstract motion displays complying with human kinematics activate the observer's motor cortex. However, it is unknown whether the same processes are active in the two conditions. Here, we addressed this issue using transcranial magnetic stimulation (TMS) to directly compare cortico-spinal excitability during observation of actions and motion stimuli that complied with or violated normal human kinematics. We found that kinematics significantly modulated the motor-evoked potentials (MEPs) produced by TMS during observation of both human and abstract motion stimuli. However, only the temporal unfolding of cortico-spinal excitability during observation of human movements significantly correlated with instantaneous stimulus velocity. This correlation was present for normal movements and also for a subset of the movements having unnatural kinematics. Furthermore, bodily movements for which we found no correlation between MEPs and stimulus velocity produced significantly higher MEPs. Our novel results suggest a dissociation in how human movements and abstract motion displays engage the observer's motor system. Specifically, while both stimulus types significantly activate the observer's motor cortex, only bodily movements produce patterns of cortico-spinal excitability that closely follow the velocity profile of the observed movement. This internal "re-enactment" of observed bodily movements seems to be only partially attuned to normal human kinematics. PMID:26854559

  19. Active buildings: modelling physical activity and movement in office buildings. An observational study protocol

    PubMed Central

    Smith, Lee; Ucci, Marcella; Marmot, Alexi; Spinney, Richard; Laskowski, Marek; Sawyer, Alexia; Konstantatou, Marina; Hamer, Mark; Ambler, Gareth; Wardle, Jane; Fisher, Abigail

    2013-01-01

    Introduction Health benefits of regular participation in physical activity are well documented but population levels are low. Office layout, and in particular the number and location of office building destinations (eg, print and meeting rooms), may influence both walking time and characteristics of sitting time. No research to date has focused on the role that the layout of the indoor office environment plays in facilitating or inhibiting step counts and characteristics of sitting time. The primary aim of this study was to investigate associations between office layout and physical activity, as well as sitting time using objective measures. Methods and analysis Active buildings is a unique collaboration between public health, built environment and computer science researchers. The study involves objective monitoring complemented by a larger questionnaire arm. UK office buildings will be selected based on a variety of features, including office floor area and number of occupants. Questionnaires will include items on standard demographics, well-being, physical activity behaviour and putative socioecological correlates of workplace physical activity. Based on survey responses, approximately 30 participants will be recruited from each building into the objective monitoring arm. Participants will wear accelerometers (to monitor physical activity and sitting inside and outside the office) and a novel tracking device will be placed in the office (to record participant location) for five consecutive days. Data will be analysed using regression analyses, as well as novel agent-based modelling techniques. Ethics and dissemination The results of this study will be disseminated through peer-reviewed publications and scientific presentations. Ethical approval was obtained through the University College London Research Ethics Committee (Reference number 4400/001). PMID:24227873

  20. Lower arm electromyography (EMG) activity detection using local binary patterns.

    PubMed

    McCool, Paul; Chatlani, Navin; Petropoulakis, Lykourgos; Soraghan, John J; Menon, Radhika; Lakany, Heba

    2014-09-01

    This paper presents a new electromyography activity detection technique in which 1-D local binary pattern histograms are used to distinguish between periods of activity and inactivity in myoelectric signals. The algorithm is tested on forearm surface myoelectric signals occurring due to hand gestures. The novel features of the presented method are that: 1) activity detection is performed across multiple channels using few parameters and without the need for majority vote mechanisms, 2) there are no per-channel thresholds to be tuned, which makes the process of activity detection easier and simpler to implement and less prone to errors, 3) it is not necessary to measure the properties of the signal during a quiescent period before using the algorithm. The algorithm is compared to other offline single- and double-threshold activity detection methods and, for the data sets tested, it is shown to have a better overall performance with greater tolerance to the noise in the real data set used. PMID:24802139

  1. Temporal alignment of electrocorticographic recordings for upper limb movement

    PubMed Central

    Talakoub, Omid; Popovic, Milos R.; Navaro, Jessie; Hamani, Clement; Fonoff, Erich T.; Wong, Willy

    2015-01-01

    The detection of movement-related components of the brain activity is useful in the design of brain-machine interfaces. A common approach is to classify the brain activity into a number of templates or states. To find these templates, the neural responses are averaged over each movement task. For averaging to be effective, one must assume that the neural components occur at identical times over repeated trials. However, complex arm movements such as reaching and grasping are prone to cross-trial variability due to the way movements are performed. Typically initiation time, duration of movement and movement speed are variable even as a subject tries to reproduce the same task identically across trials. Therefore, movement-related neural activity will tend to occur at different times across the trials. Due to this mismatch, the averaging of neural activity will not bring into salience movement-related components. To address this problem, we present a method of alignment that accounts for the variabilities in the way the movements are conducted. In this study, arm speed was used to align neural activity. Four subjects had electrocorticographic (ECoG) electrodes implanted over their primary motor cortex and were asked to perform reaching and retrieving tasks using the upper limb contralateral to the site of electrode implantation. The arm speeds were aligned using a non-linear transformation of the temporal axes resulting in average spectrograms with superior visualization of movement-related neural activity when compared to averaging without alignment. PMID:25628522

  2. A Magnetoencephalographic Study of Sensorimotor Activity Differences during Unilateral and Bilateral Forearm Movements

    ERIC Educational Resources Information Center

    Nakagawa, Kei

    2010-01-01

    This study compared activation of the sensorimotor area using magnetoencephalography after unilateral and bilateral movements. Thirteen healthy individuals and a patient with mild hemiplegia performed unilateral and bilateral forearm pronation movements. Among healthy participants, there were no significant differences in motor-evoked field during…

  3. The Official-Language Movement in the United States: Contexts, Issues, and Activities.

    ERIC Educational Resources Information Center

    Amorose, Thomas

    1989-01-01

    Central concerns in the movement to make English the official language of the United States are reviewed, publications and activities of two major organizations supporting it are compared, and basic assumptions and directions of the movement are criticized. (21 references) (MSE)

  4. Pavlov's conceptualization of voluntary movements within the framework of the theory of higher nervous activity.

    PubMed

    Windholz, G

    1998-01-01

    Pavlov became interested in the nature of voluntary movements after receiving Konorski and Miller's letter in 1928 describing their experiments on conditioning of motor movements in dogs. Their paradigmatic experiment involved presenting an indifferent stimulus, followed by passive raising of the dog's leg and then reinforcement. If the same stimulus was provided during a number of trials, the animal lifted its corresponding leg. In 1928 Pavlov asked his students to condition motor movements in his laboratory. Although their findings were equivocal, Pavlov incorporated the so-called voluntary movements into his theory of higher nervous activity. Voluntary movements were responses to external environmental contingencies. On the cortical level, the motor analyzer's cells had both afferent and efferent functions. In Pavlov's view, the motor analyzer's cells established connections with the afferent cells of other sensory analyzers. Pavlov held that motor movements, as responses to external and internal environments, give humans the illusion of voluntary behavior. PMID:9805363

  5. Stepping Out of the Shade: Control of Neuronal Activity by the Scaffold Protein Kidins220/ARMS

    PubMed Central

    Scholz-Starke, Joachim; Cesca, Fabrizia

    2016-01-01

    The correct functioning of the nervous system depends on the exquisitely fine control of neuronal excitability and synaptic plasticity, which relies on an intricate network of protein-protein interactions and signaling that shapes neuronal homeostasis during development and in adulthood. In this complex scenario, Kinase D interacting substrate of 220 kDa/ankyrin repeat-rich membrane spanning (Kidins220/ARMS) acts as a multi-functional scaffold protein with preferential expression in the nervous system. Engaged in a plethora of interactions with membrane receptors, cytosolic signaling components and cytoskeletal proteins, Kidins220/ARMS is implicated in numerous cellular functions including neuronal survival, neurite outgrowth and maturation and neuronal activity, often in the context of neurotrophin (NT) signaling pathways. Recent studies have highlighted a number of cell- and context-specific roles for this protein in the control of synaptic transmission and neuronal excitability, which are at present far from being completely understood. In addition, some evidence has began to emerge, linking alterations of Kidins220 expression to the onset of various neurodegenerative diseases and neuropsychiatric disorders. In this review, we present a concise summary of our fragmentary knowledge of Kidins220/ARMS biological functions, focusing on the mechanism(s) by which it controls various aspects of neuronal activity. We have tried, where possible, to discuss the available evidence in the wider context of NT-mediated regulation, and to outline emerging roles of Kidins220/ARMS in human pathologies. PMID:27013979

  6. Changes in muscle activation and force generation patterns during cycling movements because of low-intensity squat training with slow movement and tonic force generation.

    PubMed

    Tanimoto, Michiya; Arakawa, Hiroshi; Sanada, Kiyoshi; Miyachi, Motohiko; Ishii, Naokata

    2009-11-01

    Our previous studies showed that relatively low-load (approximately 50-60% 1 repetition maximum [1RM]) resistance training with slow movement and tonic force generation (LST) significantly increased muscle size and strength. However, LST is a very specific movement that differs from natural movements associated with sport activities and activities of daily life, and therefore, it might have some unfavorable effects on dynamic sport movement. We investigated the effects of LST on muscle activity and force generation patterns during cycling movement as a representative dynamic sports movement. Twenty-four healthy young men who were not in the habit of bicycle riding and did not have a history of regular resistance training were randomly assigned to the LST (approximately 60% 1RM load, 3-second lifting, and 3-second lowering movement without a relaxing phase: n = 8), a high-intensity exercise at normal speed (HM) group (85% 1RM load, 1-second lifting, 1-second lowering, and 1-second relaxed movement: n = 8), or sedentary control (CON, n = 8) group. Subjects in the training groups performed vertical squats by the assigned method. Exercise sessions consisted of 3 sets and were performed twice a week for 13 weeks. Pre- and posttraining muscle activation and force generation patterns during the cycling movements were evaluated by the coefficient of variation (CV) of the rectified electromyographic (EMG) wave from the vastus lateralis and CV of pedaling force. Both the CV of the rectified EMG and of pedaling force decreased significantly in the LST group (-21 and -18%, p < 0.05, respectively), whereas there were no significant changes in either the HN or the CON group. This decrease in CV in the LST group could mean that muscle activity and force generation during cycling movement have become more tonic. This result following LST may have an unfavorable effect on cycling movement and other dynamic sports movements. PMID:19826286

  7. Choice reaching with a LEGO arm robot (CoRLEGO): The motor system guides visual attention to movement-relevant information

    PubMed Central

    Strauss, Soeren; Woodgate, Philip J.W.; Sami, Saber A.; Heinke, Dietmar

    2015-01-01

    We present an extension of a neurobiologically inspired robotics model, termed CoRLEGO (Choice reaching with a LEGO arm robot). CoRLEGO models experimental evidence from choice reaching tasks (CRT). In a CRT participants are asked to rapidly reach and touch an item presented on the screen. These experiments show that non-target items can divert the reaching movement away from the ideal trajectory to the target item. This is seen as evidence attentional selection of reaching targets can leak into the motor system. Using competitive target selection and topological representations of motor parameters (dynamic neural fields) CoRLEGO is able to mimic this leakage effect. Furthermore if the reaching target is determined by its colour oddity (i.e. a green square among red squares or vice versa), the reaching trajectories become straighter with repetitions of the target colour (colour streaks). This colour priming effect can also be modelled with CoRLEGO. The paper also presents an extension of CoRLEGO. This extension mimics findings that transcranial direct current stimulation (tDCS) over the motor cortex modulates the colour priming effect (Woodgate et al., 2015). The results with the new CoRLEGO suggest that feedback connections from the motor system to the brain’s attentional system (parietal cortex) guide visual attention to extract movement-relevant information (i.e. colour) from visual stimuli. This paper adds to growing evidence that there is a close interaction between the motor system and the attention system. This evidence contradicts the traditional conceptualization of the motor system as the endpoint of a serial chain of processing stages. At the end of the paper we discuss CoRLEGO’s predictions and also lessons for neurobiologically inspired robotics emerging from this work. PMID:26667353

  8. Choice reaching with a LEGO arm robot (CoRLEGO): The motor system guides visual attention to movement-relevant information.

    PubMed

    Strauss, Soeren; Woodgate, Philip J W; Sami, Saber A; Heinke, Dietmar

    2015-12-01

    We present an extension of a neurobiologically inspired robotics model, termed CoRLEGO (Choice reaching with a LEGO arm robot). CoRLEGO models experimental evidence from choice reaching tasks (CRT). In a CRT participants are asked to rapidly reach and touch an item presented on the screen. These experiments show that non-target items can divert the reaching movement away from the ideal trajectory to the target item. This is seen as evidence attentional selection of reaching targets can leak into the motor system. Using competitive target selection and topological representations of motor parameters (dynamic neural fields) CoRLEGO is able to mimic this leakage effect. Furthermore if the reaching target is determined by its colour oddity (i.e. a green square among red squares or vice versa), the reaching trajectories become straighter with repetitions of the target colour (colour streaks). This colour priming effect can also be modelled with CoRLEGO. The paper also presents an extension of CoRLEGO. This extension mimics findings that transcranial direct current stimulation (tDCS) over the motor cortex modulates the colour priming effect (Woodgate et al., 2015). The results with the new CoRLEGO suggest that feedback connections from the motor system to the brain's attentional system (parietal cortex) guide visual attention to extract movement-relevant information (i.e. colour) from visual stimuli. This paper adds to growing evidence that there is a close interaction between the motor system and the attention system. This evidence contradicts the traditional conceptualization of the motor system as the endpoint of a serial chain of processing stages. At the end of the paper we discuss CoRLEGO's predictions and also lessons for neurobiologically inspired robotics emerging from this work. PMID:26667353

  9. Influence of vibration on mechanical power and electromyogram activity in human arm flexor muscles.

    PubMed

    Bosco, C; Cardinale, M; Tsarpela, O

    1999-03-01

    The aim of this study was to evaluate the influence of vibration on the mechanical properties of arm flexors. A group of 12 international level boxers, all members of the Italian national team, voluntarily participated in the experiment: all were engaged in regular boxing training. At the beginning of the study they were tested whilst performing forearm flexion with an extra load equal to 5% of the subjects' body mass. Following this. one arm was given the experimental treatment (E; mechanical vibration) and the other was the control (no treatment). The E treatment consisted of five repetitions lasting 1-min each of mechanical vibration applied during arm flexion in isometric conditions with 1 min rest between them. Further tests were performed 5 min immediately after the treatment on both limbs. The results showed statistically significant enhancement of the average power in the arm treated with vibrations. The root mean square electromyogram (EMGrms) had not changed following the treatment but, when divided by mechanical power, (P) as an index of neural efficiency, it showed statistically significant increases. It was concluded that mechanical vibrations enhanced muscle P and decreased the related EMG/P relationship in elite athletes. Moreover, the analysis of EMGrms recorded before the treatment and during the treatment itself showed an enormous increase in neural activity during vibration up to more than twice the baseline values. This would indicate that this type of treatment is able to stimulate the neuromuscular system more than other treatments used to improve neuromuscular properties. PMID:10090628

  10. The activation of the cortical hand area by toe tapping in two bilateral upper-extremities amputees with extraordinary foot movement skill.

    PubMed

    Yu, Xiaojing; Zhang, Shizheng; Liu, Hai; Chen, Yizhang

    2006-01-01

    Functional reorganization of the human brain after an arm amputation has been documented in several investigations, but as far as we know, there has been no report on amputees with skilled foot movement ability. To further assess the power of functional reorganization of the brain after an amputation, we investigated two bilateral upper-extremities amputees who were professional sculptors and painters with their feet. Performance tests showed that they possessed high foot movement ability. Functional MRI data indicated that toe tapping of the amputees not only activated the classical foot primary motor cortex, but also activated the hand area. In the T1-weighted MRI, the central sulci of both amputees kept their characteristic shape. Our study suggests that there is a remarkable power of neural plasticity in the motor cortex, and the maturation of the cortex develops in response to daily practice. The possible mechanisms of the reorganization are tentatively discussed. PMID:16410177

  11. Cortical Activity during a Highly-Trained Resistance Exercise Movement Emphasizing Force, Power or Volume

    PubMed Central

    Flanagan, Shawn D.; Dunn-Lewis, Courtenay; Comstock, Brett A.; Maresh, Carl M.; Volek, Jeff S.; Denegar, Craig R.; Kraemer, William J.

    2012-01-01

    Cortical activity is thought to reflect the biomechanical properties of movement (e.g., force or velocity of movement), but fatigue and movement familiarity are important factors that require additional consideration in electrophysiological research. The purpose of this within-group quantitative electroencephalogram (EEG) investigation was to examine changes in cortical activity amplitude and location during four resistance exercise movement protocols emphasizing rate (PWR), magnitude (FOR), or volume (VOL) of force production, while accounting for movement familiarity and fatigue. EEG signals were recorded during each complete repetition and were then grouped by functional region, processed to eliminate artifacts, and averaged to compare overall differences in the magnitude and location of cortical activity between protocols over the course of six sets. Biomechanical, biochemical, and exertional data were collected to contextualize electrophysiological data. The most fatiguing protocols were accompanied by the greatest increases in cortical activity. Furthermore, despite non-incremental loading and lower force levels, VOL displayed the largest increases in cortical activity over time and greatest motor and sensory activity overall. Our findings suggest that cortical activity is strongly related to aspects of fatigue during a high intensity resistance exercise movement. PMID:24961265

  12. Adaptability and Prediction of Anticipatory Muscular Activity Parameters to Different Movements in the Sitting Position.

    PubMed

    Chikh, Soufien; Watelain, Eric; Faupin, Arnaud; Pinti, Antonio; Jarraya, Mohamed; Garnier, Cyril

    2016-08-01

    Voluntary movement often causes postural perturbation that requires an anticipatory postural adjustment to minimize perturbation and increase the efficiency and coordination during execution. This systematic review focuses specifically on the relationship between the parameters of anticipatory muscular activities and movement finality in sitting position among adults, to study the adaptability and predictability of anticipatory muscular activities parameters to different movements and conditions in sitting position in adults. A systematic literature search was performed using PubMed, Science Direct, Web of Science, Springer-Link, Engineering Village, and EbscoHost. Inclusion and exclusion criteria were applied to retain the most rigorous and specific studies, yielding 76 articles, Seventeen articles were excluded at first reading, and after the application of inclusion and exclusion criteria, 23 were retained. In a sitting position, central nervous system activity precedes movement by diverse anticipatory muscular activities and shows the ability to adapt anticipatory muscular activity parameters to the movement direction, postural stability, or charge weight. In addition, these parameters could be adapted to the speed of execution, as found for the standing position. Parameters of anticipatory muscular activities (duration, order, and amplitude of muscle contractions constituting the anticipatory muscular activity) could be used as a predictive indicator of forthcoming movement. In addition, this systematic review may improve methodology in empirical studies and assistive technology for people with disabilities. PMID:27440765

  13. Coordination of multiple robot arms

    NASA Technical Reports Server (NTRS)

    Barker, L. K.; Soloway, D.

    1987-01-01

    Kinematic resolved-rate control from one robot arm is extended to the coordinated control of multiple robot arms in the movement of an object. The structure supports the general movement of one axis system (moving reference frame) with respect to another axis system (control reference frame) by one or more robot arms. The grippers of the robot arms do not have to be parallel or at any pre-disposed positions on the object. For multiarm control, the operator chooses the same moving and control reference frames for each of the robot arms. Consequently, each arm then moves as though it were carrying out the commanded motions by itself.

  14. Analysis of neck muscle activity and comparison of head movement and body movement during rotational motion.

    PubMed

    Sirikantharajah, Shahini; Valter McConville, Kristiina M; Zolfaghari, Nika

    2015-08-01

    The neck is a very delicate part of the body that is highly prone to whiplash injuries, during jerk. A lot of the research relating to whiplash injuries performed to date has been tested in environments with linear motions and have mostly applied their work to car collisions. Whiplash injuries can also affect disabled individuals during falls, bed transfers, and while travelling in wheelchairs. The primary objective of this paper was to focus on neck and body behaviour during rotational motion, rather than linear motion which has been often associated with car collisions. This paper takes the current motion signal processing technique a step further by computing the differential between head and body motion. Neck electromyogram (EMG) and angular velocity data of the head and body were acquired simultaneously from 20 subjects, as they were rotated 45 degrees in the forward pitch plane, with and without visual input, in a motion simulator. The centre of rotation (COR) on the simulator was located behind the subject Results showed that neck muscle behaviour was affected by the forward rotations, as well as visual input. Anterior neck muscles were most active during forward rotations and trials including VR. Maximum effective muscle power and activity of 10.54% and 55.72 (mV/mV)·s were reached respectively. Furthermore, during forward rotations the motion profiles started off with dominance in body motion, followed by dominance in head motion. PMID:26737049

  15. Validity of a small low-cost triaxial accelerometer with integrated logger for uncomplicated measurements of postures and movements of head, upper back and upper arms.

    PubMed

    Dahlqvist, Camilla; Hansson, Gert-Åke; Forsman, Mikael

    2016-07-01

    Repetitive work and work in constrained postures are risk factors for developing musculoskeletal disorders. Low-cost, user-friendly technical methods to quantify these risks are needed. The aims were to validate inclination angles and velocities of one model of the new generation of accelerometers with integrated data loggers against a previously validated one, and to compare meaurements when using a plain reference posture with that of a standardized one. All mean (n = 12 subjects) angular RMS-differences in 4 work tasks and 4 body parts were <2.5° and all mean median angular velocity differences <5.0 °/s. The mean correlation between the inclination signal-pairs was 0.996. This model of the new generation of triaxial accelerometers proved to be comparable to the validated accelerometer using a data logger. This makes it well-suited, for both researchers and practitioners, to measure postures and movements during work. Further work is needed for validation of the plain reference posture for upper arms. PMID:26995040

  16. Extraction and Classification of Multichannel Electromyographic Activation Trajectories for Hand Movement Recognition.

    PubMed

    AbdelMaseeh, Meena; Chen, Tsu-Wei; Stashuk, Daniel W

    2016-06-01

    This paper proposes a system for hand movement recognition using multichannel electromyographic (EMG) signals obtained from the forearm surface. This system can be used to control prostheses or to provide inputs for a wide range of human computer interface systems. In this work, the hand movement recognition problem is formulated as a multi-class distance based classification of multi-dimensional sequences. More specifically, the extraction of multi-channel EMG activation trajectories underlying hand movements, and classifying the extracted trajectories using a metric based on multi-dimensional dynamic time warping are investigated. The developed methods are evaluated using the publicly available NINAPro database comprised of 40 different hand movements performed by 40 subjects. The average movement error rate obtained across the 40 subjects is 0.09±0.047. The low error rate demonstrates the efficacy of the proposed trajectory extraction method and the discriminability of the utilized distance metric. PMID:26099148

  17. Prediction of switching time between movement preparation and execution by neural activity in monkey premotor cortex.

    PubMed

    Li, Hongbao; Liao, Yuxi; Wang, Yiwen; Zhang, Qiaosheng; Zhang, Shaomin; Zheng, Xiaoxiang

    2015-01-01

    Premotor cortex is a higher level cortex than primary motor cortex in movement controlling hierarchy, which contributes to the motor preparation and execution simultaneously during the planned movement. The mediation mechanism from movement preparation to execution has attracted many scientists' attention. Gateway hypothesis is one possible explanation that some neurons act as "gating" to release the movement intention at the "on-go" cue. We propose to utilize a local-learning based feature extraction method to target the neurons in premotor cortex, which functionally contribute mostly to the discrimination between motor preparation and execution without tuning information to either target or movement trajectory. Then the support vector machine is utilized to predict the single trial switching time. With top three functional "gating" neurons, the prediction accuracy rate of the switching time is above 90%, which indicates the potential of asynchronous BMI control using premotor cortical activity. PMID:26736827

  18. [A clinical study on the relationship between chewing movements and masticatory muscle activities].

    PubMed

    Higashi, K

    1989-06-01

    Chewing movement is one of the most important functional and physiological jaw movements, and it is coordinated by the three elements of the functional occlusion system (teeth, TMJs and masticatory muscles). However, the relationship between chewing movement and these elements has not been clarified. The purpose of this study was to investigate the relationship between chewing movement and the activity of the masticatory muscles which directly control jaw movements. 25 subjects with normal stomatognathic function, 5 patients with MPD syndrome (muscle dysfunction group) and 5 patients with unilateral TMJ internal derangement (TMJ dysfunction group) were selected. 6 gums with different hardness were used as the test bolus. Sirognathograph Electromyograph Analysing System was used to simultaneously record chewing movements and electromyograms of the right and left masseter, anterior temporal, posterior temporal and anterior belly of digastric muscles. Using the analysing software which was developed for this study, chewing movements and muscle activities were analysed. The results were as follow; A. In normal subjects 1. Gum hardness influenced durations of the closing and occluding phases, maximum opening and closing speed, opening degree and deviation of opening and closing path. 2. Gum hardness influenced muscle activities except of the time factors of digastric bursts. 3. Durations of the closing and occluding phases were found to be related with the elevator muscle activities. Maximum closing speed was related with the masseter and anterior temporal muscle activities. Deviation of closing path was related with the anterior and posterior temporal muscle activities. B. In abnormal subjects 1. The changes mainly observed in the muscle activities were found to be significantly different between the muscle dysfunction group and normal group. Similarly, the changes mainly observed in the chewing movements were different between the TMJ dysfunction group and normal

  19. Contribution of the cerebellar flocculus to gaze control during active head movements

    NASA Technical Reports Server (NTRS)

    Belton, T.; McCrea, R. A.; Peterson, B. W. (Principal Investigator)

    1999-01-01

    The flocculus and ventral paraflocculus are adjacent regions of the cerebellar cortex that are essential for controlling smooth pursuit eye movements and for altering the performance of the vestibulo-ocular reflex (VOR). The question addressed in this study is whether these regions of the cerebellum are more globally involved in controlling gaze, regardless of whether eye or active head movements are used to pursue moving visual targets. Single-unit recordings were obtained from Purkinje (Pk) cells in the floccular region of squirrel monkeys that were trained to fixate and pursue small visual targets. Cell firing rate was recorded during smooth pursuit eye movements, cancellation of the VOR, combined eye-head pursuit, and spontaneous gaze shifts in the absence of targets. Pk cells were found to be much less sensitive to gaze velocity during combined eye-head pursuit than during ocular pursuit. They were not sensitive to gaze or head velocity during gaze saccades. Temporary inactivation of the floccular region by muscimol injection compromised ocular pursuit but had little effect on the ability of monkeys to pursue visual targets with head movements or to cancel the VOR during active head movements. Thus the signals produced by Pk cells in the floccular region are necessary for controlling smooth pursuit eye movements but not for coordinating gaze during active head movements. The results imply that individual functional modules in the cerebellar cortex are less involved in the global organization and coordination of movements than with parametric control of movements produced by a specific part of the body.

  20. Fundamental Movement Skills and Physical Activity among Children with and without Cerebral Palsy

    ERIC Educational Resources Information Center

    Capio, Catherine M.; Sit, Cindy H. P.; Abernethy, Bruce; Masters, Rich S. W.

    2012-01-01

    Fundamental movement skills (FMS) proficiency is believed to influence children's physical activity (PA), with those more proficient tending to be more active. Children with cerebral palsy (CP), who represent the largest diagnostic group treated in pediatric rehabilitation, have been found to be less active than typically developing children. This…

  1. Tracking performance of unbalanced QPSK demodulators. II - Biphase Costas loop with active arm filters

    NASA Technical Reports Server (NTRS)

    Simon, M. K.

    1978-01-01

    In a Costas loop study for biphase modulation conducted by Simon and Lindsey (1977), it was demonstrated that considerable improvement in tracking performance could be obtained by employing active arm filters of the integrate-and-dump type as opposed to passive arm filters. An investigation is conducted concerning the possibility to obtain a similar performance improvement for an unbalanced quadriphase-shift-keying (QPSK) modulation. It is found that the biphase Costas loop can be used as an efficient demodulator of QPSK in cases in which the ratio of data rates is of the same order of magnitude as the inverse of the power ratio. These cases involve approximately equal signal energies in the two channels.

  2. Phasic motor activity reduction occurring with horizontal rapid eye movements during active sleep in human.

    PubMed

    Kohyama, J; Shimohira, M; Hasegawa, T; Kouji, T; Iwakawa, Y

    1995-01-01

    We describe the phasic reduction of motor activity occurring with horizontal rapid eye movements (REMs) during active sleep in 15 children (12 healthy children and 3 patients with severe brain damage). A REM-related decrease in intercostal muscle activity was demonstrated by averaging integrated surface electromyograms. In the healthy subjects, this reduction had a mean latency from the REM onset of 37.1 ms and a duration of 225.9 ms. This phenomenon was also observed in the 3 patients who had lost cerebral function. We hypothesized a brainstem origin for the effect. A REM-related mentalis muscle activity loss, detected by averaging mentalis muscle twitches, was observed in 10 healthy children among the subjects. This loss began at 59.1 ms before the onset of REMs and lasted for 230.2 ms on average. In addition, a transient decrease in integrated REM activity surrounding mentalis muscle twitches (a twitch-related reduction of REMs) was observed. We discuss the similarity between REM-related phasic reduction of muscle activity obtained for intercostal and mentalis muscles and pontogeniculo-occipital (PGO) wave-related inhibitory postsynaptic potentials reported for feline lumbar and trigeminal motoneurons, respectively. We then assume the presence of a phasic event generator, functioning during active sleep in healthy humans, which triggers at least three generators; that is, the generator of PGO waves (or REMs), motor inhibition, and of motor excitation including muscle twitches. PMID:8751071

  3. Neostriatal Neuronal Activity Correlates Better with Movement Kinematics under Certain Rewards.

    PubMed

    Opris, Ioan; Lebedev, Mikhail A; Nelson, Randall J

    2016-01-01

    This study investigated how the activity of neostriatal neurons is related to the kinematics of movement when monkeys performed visually and vibratory cued wrist extensions and flexions. Single-unit recordings of 142/236 neostriatal neurons showed pre-movement activity (PMA) in a reaction time task with unpredictable reward. Monkeys were pseudo-randomly (75%) rewarded for correct performance. A regression model was used to determine whether the correlation between neostriatal neuronal activity and the kinematic variables (position, velocity, and acceleration) of wrist movement changes as a function of reward contingency, sensory cues, and movement direction. The coefficients of determination (CoD) representing the proportion of the variance in neuronal activity explained by the regression model on a trial by trial basis, together with their temporal occurrences (time of best regression/correlation, ToC) were compared across sensory modality, movement direction, and reward contingency. The best relationship (correlation) between neuronal activity and movement kinematic variables, given by the average coefficient of determination (CoD), was: (a) greater during trials in which rewards were certain, called "A" trials, as compared with those in which reward was uncertain called ("R") trials, (b) greater during flexion (Flex) trials as compared with extension (Ext) trials, and (c) greater during visual (VIS) cued trials than during vibratory (VIB) cued trials, for the same type of trial and the same movement direction. These results are consistent with the hypothesis that predictability of reward for correct performance is accompanied by faster linkage between neostriatal PMA and the vigor of wrist movement kinematics. Furthermore, the results provide valuable insights for building an upper-limb neuroprosthesis. PMID:27579022

  4. Neostriatal Neuronal Activity Correlates Better with Movement Kinematics under Certain Rewards

    PubMed Central

    Opris, Ioan; Lebedev, Mikhail A.; Nelson, Randall J.

    2016-01-01

    This study investigated how the activity of neostriatal neurons is related to the kinematics of movement when monkeys performed visually and vibratory cued wrist extensions and flexions. Single-unit recordings of 142/236 neostriatal neurons showed pre-movement activity (PMA) in a reaction time task with unpredictable reward. Monkeys were pseudo-randomly (75%) rewarded for correct performance. A regression model was used to determine whether the correlation between neostriatal neuronal activity and the kinematic variables (position, velocity, and acceleration) of wrist movement changes as a function of reward contingency, sensory cues, and movement direction. The coefficients of determination (CoD) representing the proportion of the variance in neuronal activity explained by the regression model on a trial by trial basis, together with their temporal occurrences (time of best regression/correlation, ToC) were compared across sensory modality, movement direction, and reward contingency. The best relationship (correlation) between neuronal activity and movement kinematic variables, given by the average coefficient of determination (CoD), was: (a) greater during trials in which rewards were certain, called “A” trials, as compared with those in which reward was uncertain called (“R”) trials, (b) greater during flexion (Flex) trials as compared with extension (Ext) trials, and (c) greater during visual (VIS) cued trials than during vibratory (VIB) cued trials, for the same type of trial and the same movement direction. These results are consistent with the hypothesis that predictability of reward for correct performance is accompanied by faster linkage between neostriatal PMA and the vigor of wrist movement kinematics. Furthermore, the results provide valuable insights for building an upper-limb neuroprosthesis. PMID:27579022

  5. Cortical activity prior to, and during, observation and execution of sequential finger movements.

    PubMed

    Calmels, Claire; Holmes, Paul; Jarry, Gilbert; Lévèque, Jean-Michel; Hars, Magaly; Stam, Cornelis J

    2006-01-01

    The aim of this study was to provide further evidence for the existence of a mirror neuron system in humans using electroencephalography during the observation and execution of non-object-related movements. Event-related desynchronization and synchronization (ERD/ERS) were used to characterize brain activity prior to, and during, observation and execution of a finger movement in four frequency bands (7-10 Hz, 10-13 Hz, 13-20 Hz, and 20-30 Hz). Electroencephalograms (EEGs) were recorded from 19 electrode sites in eight participants. In all the frequency bands and electrode sites, results revealed that there was no significant differences in EEG cortical activity between the observation condition and the execution conditions. Comparison of the two stages of the movement (i.e., pre-movement and movement) in the observation and execution conditions showed, in most cases, that pre-movement ERD values were less than movement ERD values. Whilst there was not an identical match of EEG cortical indices, this study provides further support for the existence of a mirror neuron system in humans. The incomplete congruence may be explained by the different behaviors, the nature of the task and factors in the observed action coded by the mirror system. PMID:17136468

  6. From sedentary to active: Shifting the movement paradigm in workplaces.

    PubMed

    Das, Bhibha M; Mailey, Emily; Murray, Kate; Phillips, Siobhan M; Torres, Cam; King, Abby C

    2016-06-01

    Increased sedentary behavior and reduced physical activity are risk factors for morbidity and mortality. As adults spend a significant portion of their time at work where the default is to spend the majority of the day sitting, shifting workplace norms to decrease sedentary time and increase active time could have a public health impact. Workplaces offer a unique setting for multi-level interventions that can reach diverse populations. Traditional worksite wellness initiatives have produced equivocal results in terms of increasing physical activity. One reason for this may be the focus on corporate-fitness type programs and health education with little change in workplace culture. More innovative approaches combining theory-based worksite wellness components with behavioral economics approaches promoting incidental physical activity at the workplace to make activity the default may be necessary. This article discusses strategies to shift the workplace paradigm from being sedentary to more active using a range of approaches. PMID:27286083

  7. Phasic activity in the human erector spinae during repetitive hand movements.

    PubMed Central

    Zedka, M; Prochazka, A

    1997-01-01

    1. Phasic activity in the human back muscle erector spinae (ES) was studied during repetitive hand movements. The hand movements were elicited voluntarily by the subject or induced passively by the experimenter through a servomotor or through cyclical electrical stimulation of muscles acting about the wrist. The aim of the study was to determine whether the rhythmical activation of ES was of supraspinal, intersegmental or segmental origin. 2. When voluntary rhythmical hand movements were performed as fast as possible, cyclical ES EMG bursts occurred at the same frequency. This frequency was significantly higher than that reached when the task was to contract the back muscles as rapidly as possible. This suggests that the ES activity during the fast hand movements was not generated by direct commands descending to the ES muscles from the motor area of the cerebral cortex responsible for voluntary back muscle activation. 3. During imposed rhythmical hand movements, ES EMG bursts remained entrained to the hand movements, even when movement frequencies far exceeded those attainable voluntarily either for the hand or the back. This showed that ES EMG responses could be evoked by the hand movements even when these were not generated by descending neural commands. Two alternative mechanisms of ES activation were considered: (a) propriospinal transmission of afferent input entering the spinal cord from the upper extremity; (b) afferent input from ES and other trunk muscles, responding to local oscillations transmitted mechanically from the hand to the lower back. 4. Activation of ES via proprioceptive signals from the forearm was unlikely since (a) simultaneous electrical stimulation of wrist extensor and wrist flexor muscles did not result in repetitive ES EMG bursting; (b) cyclical vibration of the wrist extensors did not evoke ES EMG bursting; (c) when the forearm was constrained and the hand was moved passively, the lower trunk accelerations and cyclical ES EMG both

  8. Development of Junior High School Students' Fundamental Movement Skills and Physical Activity in a Naturalistic Physical Education Setting

    ERIC Educational Resources Information Center

    Kalaja, Sami Pekka; Jaakkola, Timo Tapio; Liukkonen, Jarmo Olavi; Digelidis, Nikolaos

    2012-01-01

    Background: There is evidence showing that fundamental movement skills and physical activity are related with each other. The ability to perform a variety of fundamental movement skills increases the likelihood of children participating in different physical activities throughout their lives. However, no fundamental movement skill interventions…

  9. Movement and Learning: Integrating Physical Activity into the Classroom

    ERIC Educational Resources Information Center

    Reeves, Emily; Miller, Stacia; Chavez, Crystal

    2016-01-01

    We know the benefits of physical activity, and yet recess and physical education classes are being cut or scaled back to make room for meeting academic standards. Is cutting recess and physical education really benefiting academics? A look at some recent studies suggests that it is not. Integrating physical activity into the classroom may increase…

  10. Young School Children's Recess Physical Activity: Movement Patterns and Preferences

    ERIC Educational Resources Information Center

    Woods, Amelia M.; Graber, Kim C.; Daum, David N.; Gentry, Chris

    2015-01-01

    This study examined physical activity (PA) variables related to recess PA patterns of kindergarten, first and second grade children, and the social preferences and individuals influencing their PA. Data collected (N = 147) used the System of Observing Children's Activity and Relationships during Play (SOCARP) instrument. Children were interviewed.…

  11. Using Movement and Intentions to Understand Human Activity

    ERIC Educational Resources Information Center

    Zacks, Jeffrey M.; Kumar, Shawn; Abrams, Richard A.; Mehta, Ritesh

    2009-01-01

    During perception, people segment continuous activity into discrete events. They do so in part by monitoring changes in features of an ongoing activity. Characterizing these features is important for theories of event perception and may be helpful for designing information systems. The three experiments reported here asked whether the body…

  12. Hindlimb movement modulates the activity of rostral fastigial nucleus neurons that process vestibular input

    PubMed Central

    McCall, Andrew A; Miller, Daniel J; Catanzaro, Michael F; Cotter, Lucy A; Yates, Bill J

    2015-01-01

    Integration of vestibular and proprioceptive afferent information within the central nervous system is a critical component of postural regulation. We recently demonstrated that labyrinthine and hindlimb signals converge onto vestibular nucleus neurons, such that hindlimb movement modulates the activity of these cells. However, it is unclear whether similar convergence of hindlimb and vestibular signals also occurs upstream from the vestibular nuclei, particularly in the rostral fastigial nucleus (rFN). We tested the hypothesis that rFN neurons have similar responses to hindlimb movement as vestibular nucleus neurons. Recordings were obtained from 53 rFN neurons that responded to hindlimb movement in decerebrate cats. In contrast to vestibular nucleus neurons, which commonly encoded the direction of hindlimb movement (81% of neurons), few rFN neurons (21%) that responded to leg movement encoded such information. Instead, most rFN neurons responded to both limb flexion and extension. Half of the rFN neurons whose activity was modulated by hindlimb movement received convergent vestibular inputs. These results show that rFN neurons receive somatosensory inputs from the hindlimb, and that a subset of rFN neurons integrates vestibular and hindlimb signals. Such rFN neurons likely perform computations that participate in maintenance of balance during upright stance and movement. Although vestibular nucleus neurons are interconnected with the rFN, the dissimilarity of responses of neurons sensitive to hindlimb movement in the two regions suggest that they play different roles in coordinating postural responses during locomotion and other movements which entail changes in limb position. PMID:25976518

  13. Hindlimb movement modulates the activity of rostral fastigial nucleus neurons that process vestibular input.

    PubMed

    McCall, Andrew A; Miller, Daniel J; Catanzaro, Michael F; Cotter, Lucy A; Yates, Bill J

    2015-08-01

    Integration of vestibular and proprioceptive afferent information within the central nervous system is a critical component of postural regulation. We recently demonstrated that labyrinthine and hindlimb signals converge onto vestibular nucleus neurons, such that hindlimb movement modulates the activity of these cells. However, it is unclear whether similar convergence of hindlimb and vestibular signals also occurs upstream from the vestibular nuclei, particularly in the rostral fastigial nucleus (rFN). We tested the hypothesis that rFN neurons have similar responses to hindlimb movement as vestibular nucleus neurons. Recordings were obtained from 53 rFN neurons that responded to hindlimb movement in decerebrate cats. In contrast to vestibular nucleus neurons, which commonly encoded the direction of hindlimb movement (81 % of neurons), few rFN neurons (21 %) that responded to leg movement encoded such information. Instead, most rFN neurons responded to both limb flexion and extension. Half of the rFN neurons whose activity was modulated by hindlimb movement received convergent vestibular inputs. These results show that rFN neurons receive somatosensory inputs from the hindlimb and that a subset of rFN neurons integrates vestibular and hindlimb signals. Such rFN neurons likely perform computations that participate in maintenance of balance during upright stance and movement. Although vestibular nucleus neurons are interconnected with the rFN, the dissimilarity of responses of neurons sensitive to hindlimb movement in the two regions suggests that they play different roles in coordinating postural responses during locomotion and other movements which entail changes in limb position. PMID:25976518

  14. A Visual Analytics Approach to Structured Data Analysis to Enhance Nonproliferation and Arms Control Verification Activities

    SciTech Connect

    Gillen, David S.

    2014-08-07

    Analysis activities for Nonproliferation and Arms Control verification require the use of many types of data. Tabular structured data, such as Excel spreadsheets and relational databases, have traditionally been used for data mining activities, where specific queries are issued against data to look for matching results. The application of visual analytics tools to structured data enables further exploration of datasets to promote discovery of previously unknown results. This paper discusses the application of a specific visual analytics tool to datasets related to the field of Arms Control and Nonproliferation to promote the use of visual analytics more broadly in this domain. Visual analytics focuses on analytical reasoning facilitated by interactive visual interfaces (Wong and Thomas 2004). It promotes exploratory analysis of data, and complements data mining technologies where known patterns can be mined for. Also with a human in the loop, they can bring in domain knowledge and subject matter expertise. Visual analytics has not widely been applied to this domain. In this paper, we will focus on one type of data: structured data, and show the results of applying a specific visual analytics tool to answer questions in the Arms Control and Nonproliferation domain. We chose to use the T.Rex tool, a visual analytics tool developed at PNNL, which uses a variety of visual exploration patterns to discover relationships in structured datasets, including a facet view, graph view, matrix view, and timeline view. The facet view enables discovery of relationships between categorical information, such as countries and locations. The graph tool visualizes node-link relationship patterns, such as the flow of materials being shipped between parties. The matrix visualization shows highly correlated categories of information. The timeline view shows temporal patterns in data. In this paper, we will use T.Rex with two different datasets to demonstrate how interactive exploration of

  15. State-based decoding of hand and finger kinematics using neuronal ensemble and LFP activity during dexterous reach-to-grasp movements

    PubMed Central

    Mollazadeh, Mohsen; Davidson, Adam G.; Schieber, Marc H.; Thakor, Nitish V.

    2013-01-01

    The performance of brain-machine interfaces (BMIs) that continuously control upper limb neuroprostheses may benefit from distinguishing periods of posture and movement so as to prevent inappropriate movement of the prosthesis. Few studies, however, have investigated how decoding behavioral states and detecting the transitions between posture and movement could be used autonomously to trigger a kinematic decoder. We recorded simultaneous neuronal ensemble and local field potential (LFP) activity from microelectrode arrays in primary motor cortex (M1) and dorsal (PMd) and ventral (PMv) premotor areas of two male rhesus monkeys performing a center-out reach-and-grasp task, while upper limb kinematics were tracked with a motion capture system with markers on the dorsal aspect of the forearm, hand, and fingers. A state decoder was trained to distinguish four behavioral states (baseline, reaction, movement, hold), while a kinematic decoder was trained to continuously decode hand end point position and 18 joint angles of the wrist and fingers. LFP amplitude most accurately predicted transition into the reaction (62%) and movement (73%) states, while spikes most accurately decoded arm, hand, and finger kinematics during movement. Using an LFP-based state decoder to trigger a spike-based kinematic decoder [r = 0.72, root mean squared error (RMSE) = 0.15] significantly improved decoding of reach-to-grasp movements from baseline to final hold, compared with either a spike-based state decoder combined with a spike-based kinematic decoder (r = 0.70, RMSE = 0.17) or a spike-based kinematic decoder alone (r = 0.67, RMSE = 0.17). Combining LFP-based state decoding with spike-based kinematic decoding may be a valuable step toward the realization of BMI control of a multifingered neuroprosthesis performing dexterous manipulation. PMID:23536714

  16. Analysis of upper arm muscle activation using surface electromyography signals during drum playing.

    PubMed

    Chong, Hyun Ju; Kwon, Chun-Ki; Kang, Hyun-Joo; Kim, Soo Ji

    2016-06-01

    This study measured surface electromyography of the biceps brachii and triceps brachii during repeated drum playing with and without a drumstick to better understand activation of the upper arm muscles and inform the use of instrument playing for motor rehabilitation. A total of 40 healthy college students participated in this study. All participants were asked to strike a drum with their hand and with a drumstick at three different levels of stroke: soft, medium, and strong. The stroke order was randomly assigned to participants. A sound level meter was used to record the intensity of the drum playing. Surface electromyography signals were recorded at every hit during drum playing both with and without the drumstick in each of the three stroke conditions. The results demonstrated that the highest muscle activation was observed in both biceps brachii and triceps brachii with strong drum playing with and without the drumstick. A two-way repeated measures analysis of variance showed that there was a significant main effect for stroke intensity in muscle activation and produced sound level. While higher activation of the triceps brachii was observed for drum playing without a drumstick, no significant differences were found between the biceps brachii and sound level. This study demonstrated via surface electromyography data that greater muscle activation of the biceps brachii and triceps brachii does not occur with the use of drumsticks in drum playing. With the drum sound controlled, drum playing by hand can be an effective therapeutic intervention for the upper arm muscles. PMID:27419114

  17. Analysis of upper arm muscle activation using surface electromyography signals during drum playing

    PubMed Central

    Chong, Hyun Ju; Kwon, Chun-Ki; Kang, Hyun-Joo; Kim, Soo Ji

    2016-01-01

    This study measured surface electromyography of the biceps brachii and triceps brachii during repeated drum playing with and without a drumstick to better understand activation of the upper arm muscles and inform the use of instrument playing for motor rehabilitation. A total of 40 healthy college students participated in this study. All participants were asked to strike a drum with their hand and with a drumstick at three different levels of stroke: soft, medium, and strong. The stroke order was randomly assigned to participants. A sound level meter was used to record the intensity of the drum playing. Surface electromyography signals were recorded at every hit during drum playing both with and without the drumstick in each of the three stroke conditions. The results demonstrated that the highest muscle activation was observed in both biceps brachii and triceps brachii with strong drum playing with and without the drumstick. A two-way repeated measures analysis of variance showed that there was a significant main effect for stroke intensity in muscle activation and produced sound level. While higher activation of the triceps brachii was observed for drum playing without a drumstick, no significant differences were found between the biceps brachii and sound level. This study demonstrated via surface electromyography data that greater muscle activation of the biceps brachii and triceps brachii does not occur with the use of drumsticks in drum playing. With the drum sound controlled, drum playing by hand can be an effective therapeutic intervention for the upper arm muscles. PMID:27419114

  18. The contribution of active body movement to visual development in evolutionary robots.

    PubMed

    Suzuki, Mototaka; Floreano, Dario; Di Paolo, Ezequiel A

    2005-01-01

    Inspired by the pioneering work by Held and Hein (1963) on the development of kitten visuo-motor systems, we explore the role of active body movement in the developmental process of the visual system by using robots. The receptive fields in an evolved mobile robot are developed during active or passive movement with a Hebbian learning rule. In accordance to experimental observations in kittens, we show that the receptive fields and behavior of the robot developed under active condition significantly differ from those developed under passive condition. A possible explanation of this difference is derived by correlating receptive field formation and behavioral performance in the two conditions. PMID:16112555

  19. The Association Between Eye Movements and Cerebellar Activation in a Verbal Working Memory Task.

    PubMed

    Peterburs, Jutta; Cheng, Dominic T; Desmond, John E

    2016-09-01

    It has been argued that cerebellar activations during cognitive tasks may masquerade as cognition, while actually reflecting processes related to movement planning or motor learning. The present study investigated whether the cerebellar load effect for verbal working memory, that is, increased activations in lobule VI/Crus I and lobule VIIB/VIIIA, is related to eye movements and oculomotor processing. Fifteen participants performed an fMRI-based Sternberg verbal working memory task. Oculomotor and cognitive task demands were manipulated by using closely and widely spaced stimuli, and high and low cognitive load. Trial-based quantitative eye movement parameters were obtained from concurrent eye tracking. Conventional MRI analysis replicated the cerebellar load effect in lobules VI and VIIB/VIIIa. With quantitative eye movement parameters as regressors, analysis yielded very similar activation patterns. While load effect and eye regressor generally recruited spatially distinct neocortical and cerebellar regions, conjunction analysis showed that a small subset of prefrontal areas implicated in the load effect also responded to the eye regressor. The present results indicate that cognitive load-dependent activations in lateral superior and posteroinferior cerebellar regions in the Sternberg task are independent of eye movements occurring during stimulus encoding. This is inconsistent with the notion that cognitive load-dependent cerebellar activations merely reflect oculomotor processing. PMID:26286918

  20. Immobilization of pectinase on silica-based supports: Impacts of particle size and spacer arm on the activity.

    PubMed

    Alagöz, Dilek; Tükel, S Seyhan; Yildirim, Deniz

    2016-06-01

    The pectinase was separately immobilized onto Florisil and nano silica supports through both glutaraldehyde and 3-glyoxypropyltrietoxysilane spacer arms. The effects of spacer arm, particle size of support and ionic liquids on the activities of pectinase preparations were investigated. The immobilization of pectinase onto Florisil and nano silica through 3-glyoxypropyltrietoxysilane spacer arm completely led to inactivation of enzyme; however, 10 and 75% pectinase activity were retained when it was immobilized through glutaraldehyde spacer arm onto Florisil and nano silica, respectively. The pectinase immobilized onto nano silica through glutaraldehyde spacer arm showed 6.3-fold higher catalytic efficiency than that of the pectinase immobilized onto Florisil through same spacer arm. A 2.3-fold increase in thermal stability of pectinase was provided upon immobilization onto nano silica at 35°C. The effects of IL/buffer mixture and volume ratio of IL/buffer mixture on the catalytic activities of free and immobilized pectinase preparations were also tested. All the pectinase preparations showed highest activity in 10% (v/v) 1-butyl-3-methylimidazolium hexafluorophosphate containing medium and their activities significantly affected from the concentration of 1-butyl-3-methylimidazolium hexafluorophosphate. PMID:26964525

  1. Self-Administered, Home-Based SMART (Sensorimotor Active Rehabilitation Training) Arm Training: A Single-Case Report.

    PubMed

    Hayward, Kathryn S; Neibling, Bridee A; Barker, Ruth N

    2015-01-01

    This single-case, mixed-method study explored the feasibility of self-administered, home-based SMART (sensorimotor active rehabilitation training) Arm training for a 57-yr-old man with severe upper-limb disability after a right frontoparietal hemorrhagic stroke 9 mo earlier. Over 4 wk of self-administered, home-based SMART Arm training, the participant completed 2,100 repetitions unassisted. His wife provided support for equipment set-up and training progressions. Clinically meaningful improvements in arm impairment (strength), activity (arm and hand tasks), and participation (use of arm in everyday tasks) occurred after training (at 4 wk) and at follow-up (at 16 wk). Areas for refinement of SMART Arm training derived from thematic analysis of the participant's and researchers' journals focused on enabling independence, ensuring home and user friendliness, maintaining the motivation to persevere, progressing toward everyday tasks, and integrating practice into daily routine. These findings suggest that further investigation of self-administered, home-based SMART Arm training is warranted for people with stroke who have severe upper-limb disability. PMID:26114456

  2. Children's Recess Physical Activity: Movement Patterns and Preferences

    ERIC Educational Resources Information Center

    Woods, Amelia Mays; Graber, Kim C.; Daum, David Newman

    2012-01-01

    The benefits of recess can be reaped by all students regardless of socioeconomic status, race, or gender and at relatively little cost. The purpose of this study was to examine physical activity (PA) variables related to the recess PA patterns of third and fourth grade children and the social preferences and individuals influencing their PA…

  3. Movement Activity Levels on Traditional and Contemporary Playground Structures.

    ERIC Educational Resources Information Center

    Gabbard, Carl P.; LeBlanc, Elizabeth

    This study investigated playground activity levels of children in grades K-4 and compared levels of use of traditional and creative playground apparatus. The traditional playground area consisted of climbing bars, slides, ladders, chin bars, swings, see saws, and a merry-go-round. The creative playground contained tire hurdles, tire walk, tire…

  4. 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…

  5. Self-Schemata for Movement Activities: The Influence of Race and Gender.

    ERIC Educational Resources Information Center

    Harrison, Louis, Jr.; And Others

    This study investigated the influence of race and gender on students' self-schema for movement activities. Study participants were 168 male and female seventh- and eighth-grade students, both African American and Euro American, from a semi-rural school in a Southeastern state. The Physical Activity Schema Analysis (PASA) was administered to…

  6. Brainstem glycinergic neurons and their activation during active (rapid eye movement) sleep in the cat.

    PubMed

    Morales, F R; Sampogna, S; Rampon, C; Luppi, P H; Chase, M H

    2006-09-29

    It is well established that, during rapid eye movement (REM) sleep, somatic motoneurons are subjected to a barrage of inhibitory synaptic potentials that are mediated by glycine. However, the source of this inhibition, which is crucial for the maintenance and preservation of REM sleep, has not been identified. Consequently, the present study was undertaken to determine in cats the location of the glycinergic neurons, that are activated during active sleep, and are responsible for the postsynaptic inhibition of motoneurons that occurs during this state. For this purpose, a pharmacologically-induced state of active sleep (AS-carbachol) was employed. Antibodies against glycine-conjugated proteins were used to identify glycinergic neurons and immunocytochemical techniques to label the Fos protein were employed to identify activated neurons. Two distinct populations of glycinergic neurons that expressed c-fos were distinguished. One population was situated within the nucleus reticularis gigantocellularis (NRGc) and nucleus magnocellularis (Mc) in the rostro-ventral medulla; this group of neurons extended caudally to the ventral portion of the nucleus paramedianus reticularis (nPR). Forty percent of the glycinergic neurons in the NRGc and Mc and 25% in the nPR expressed c-fos during AS-carbachol. A second population was located in the caudal medulla adjacent to the nucleus ambiguus (nAmb), wherein 40% of the glycinergic cells expressed c-fos during AS-carbachol. Neither population of glycinergic cells expressed c-fos during quiet wakefulness or quiet (non-rapid eye movement) sleep. We suggest that the population of glycinergic neurons in the NRGc, Mc, and nPR participates in the inhibition of somatic brainstem motoneurons during active sleep. These neurons may also be responsible for the inhibition of sensory and other processes during this state. It is likely that the group of glycinergic neurons adjacent to the nucleus ambiguus (nAmb) is responsible for the active

  7. Movement-related parameters modulate cortical activity during imaginary isometric plantar-flexions.

    PubMed

    do Nascimento, Omar Feix; Nielsen, Kim Dremstrup; Voigt, Michael

    2006-05-01

    A multitude of studies have demonstrated a clear activation of the motor cortex during imagination of various motor tasks; however, it is still unclear if movement-related parameters (movement direction, range of motion, speed, force level and rate of force development) specifically modulate cortical activation as they do during the execution of actual motor tasks. Accordingly, this study examined whether the rate of torque development (RTD) and/or the torque amplitude modulates cortical potentials generated during imaginary motor tasks. Fifteen subjects imagined four different left-sided isometric plantar-flexion tasks, while EEG and EMG recordings were being performed. The averaged EEG activity was analyzed in terms of movement-related potentials (MRPs), consisting of readiness potential (RP), motor potential (MP) and movement-monitoring potential (MMP). It was demonstrated that RTD and torque amplitude indeed modulate cortical activity during imaginary motor tasks. Information concerning movement-related parameters for imaginary plantar-flexion tasks seems to be encoded in the supplementary motor area (SMA) and the primary motor cortex (M1). A comparison between MRPs of imaginary and actual motor tasks revealed that early MRPs were morphologically similar, but differed significantly in amplitude. One of the possible suggestions to explain such a difference may be an "abortion" of ongoing motor programs. PMID:16320044

  8. Role of Synchronous Activation of Cerebellar Purkinje Cell Ensembles in Multi-joint Movement Control

    PubMed Central

    Hoogland, Tycho M.; De Gruijl, Jornt R.; Witter, Laurens; Canto, Cathrin B.; De Zeeuw, Chris I.

    2015-01-01

    Summary It is a longstanding question in neuroscience how elaborate multi-joint movements are coordinated coherently. Microzones of cerebellar Purkinje cells (PCs) are thought to mediate this coordination by controlling the timing of particular motor domains. However, it remains to be elucidated to what extent motor coordination deficits can be correlated with abnormalities in coherent activity within these microzones and to what extent artificially evoked synchronous activity within PC ensembles can elicit multi-joint motor behavior. To study PC ensemble correlates of limb, trunk, and tail movements, we developed a transparent disk treadmill that allows quantitative readout of locomotion and posture parameters in head-fixed mice and simultaneous cellular-resolution imaging and/or optogenetic manipulation. We show that PC ensembles in the ataxic and dystonic mouse mutant tottering have a reduced level of complex spike co-activation, which is delayed relative to movement onset and co-occurs with prolonged swing duration and reduced phase coupling of limb movements as well as with enlarged deflections of body-axis and tail movements. Using optogenetics to increase simple spike rate in PC ensembles, we find that preferred locomotion and posture patterns can be elicited or perturbed depending on the behavioral state. At rest, preferred sequences of limb movements can be elicited, whereas during locomotion, preferred gait-inhibition patterns are evoked. Our findings indicate that synchronous activation of PC ensembles can facilitate initiation and coordination of limb and trunk movements, presumably by tuning downstream systems involved in the execution of behavioral patterns. PMID:25843032

  9. Eye Movements and Abducens Motoneuron Behavior after Cholinergic Activation of the Nucleus Reticularis Pontis Caudalis

    PubMed Central

    Márquez-Ruiz, Javier; Escudero, Miguel

    2010-01-01

    Study Objectives: The aim of this work was to characterize eye movements and abducens (ABD) motoneuron behavior after cholinergic activation of the nucleus reticularis pontis caudalis (NRPC). Methods: Six female adult cats were prepared for chronic recording of eye movements (using the scleral search-coil technique), electroencephalography, electromyography, ponto-geniculo-occipital (PGO) waves in the lateral geniculate nucleus, and ABD motoneuron activities after microinjections of the cholinergic agonist carbachol into the NRPC. Results: Unilateral microinjections of carbachol in the NRPC induced tonic and phasic phenomena in the oculomotor system. Tonic effects consisted of ipsiversive rotation to the injected side, convergence, and downward rotation of the eyes. Phasic effects consisted of bursts of rhythmic rapid eye movements directed contralaterally to the injected side along with PGO-like waves in the lateral geniculate and ABD nuclei. Although tonic effects were dependent on the level of drowsiness, phasic effects were always present and appeared along with normal saccades when the animal was vigilant. ABD motoneurons showed phasic activities associated with ABD PGO-like waves during bursts of rapid eye movements, and tonic and phasic activities related to eye position and velocity during alertness. Conclusion The cholinergic activation of the NRPC induces oculomotor phenomena that are somewhat similar to those described during REM sleep. A precise comparison of the dynamics and timing of the eye movements further suggests that a temporal organization of both NRPCs is needed to reproduce the complexity of the oculomotor behavior during REM sleep. Citation: Márquez-Ruiz J; Escudero M. Eye movements and abducens motoneuron behavior after cholinergic activation of the nucleus reticularis pontis caudalis. SLEEP 2010;33(11):1517-1527. PMID:21102994

  10. Protest, Performance and Politics: The Use of "Nano-Media" in Social Movement Activism in South Africa

    ERIC Educational Resources Information Center

    Dawson, Marcelle C.

    2012-01-01

    Considering the lack of coverage in the mass media of certain kinds of social movement activity, many movements make use of smaller scale, independent media to publicise their struggles. From the vantage point of social movements in South Africa, this paper addresses what Mojca Pajnik and John Downing call "nano-media". Based on interviews with…

  11. Recovery of post stroke proximal arm function, driven by complex neuroplastic bilateral brain activation patterns and predicted by baseline motor dysfunction severity

    PubMed Central

    Pundik, Svetlana; McCabe, Jessica P.; Hrovat, Ken; Fredrickson, Alice Erica; Tatsuoka, Curtis; Feng, I Jung; Daly, Janis J.

    2015-01-01

    Objectives: Neuroplastic changes that drive recovery of shoulder/elbow function after stroke have been poorly understood. The purpose of this study was to determine the relationship between neuroplastic brain changes related to shoulder/elbow movement control in response to treatment and recovery of arm motor function in chronic stroke survivors.Methods: Twenty-three chronic stroke survivors were treated with 12 weeks of arm rehabilitation. Outcome measures included functional Magnetic Resonance Imaging (fMRI) for the shoulder/elbow components of reach and a skilled motor function test (Arm Motor Abilities Test, AMAT), collected before and after treatment.Results: We observed two patterns of neuroplastic changes that were associated with gains in motor function: decreased or increased task-related brain activation. Those with significantly better motor function at baseline exhibited a decrease in brain activation in response to treatment, evident in the ipsilesional primary motor and contralesional supplementary motor regions; in contrast, those with greater baseline motor impairment, exhibited increased brain activation in response to treatment. There was a linear relationship between greater functional gain (AMAT) and increased activation in bilateral primary motor, contralesional primary and secondary sensory regions, and contralesional lateral premotor area, after adjusting for baseline AMAT, age, and time since stroke.Conclusions: Recovery of functional reach involves recruitment of several contralesional and bilateral primary motor regions. In response to intensive therapy, the direction of functional brain change (i.e., increase or decrease in task-related brain recruitment) for shoulder/elbow reach components depends on baseline level of motor function and may represent either different phases of recovery or different patterns of neuroplasticity that drive functional recovery. PMID:26257623

  12. Chronic neck pain alters muscle activation patterns to sudden movements.

    PubMed

    Boudreau, Shellie A; Falla, Deborah

    2014-06-01

    The aim of this study was to assess the activation of the sternocleidomastoid (SCM) and splenius capitis (SC) muscles in response to unanticipated, full body perturbations in individuals with chronic neck pain (NP) and age-matched healthy controls (HC). Individuals with NP had a history of NP for 8.9 ± 7.8 years, rated the intensity of NP as 4.2 ± 2.0 (score out of 10), and scored 15.3 ± 6.5 on the Neck Disability Index. Participants stood on a moveable platform during which 32 randomized postural perturbations (eight repetitions of four perturbation types: 8 cm forward slide (FS), 8 cm backward slides, 10° forward tilt, and 10° backward tilt) with varying inter-perturbation time intervals were performed over a period of 5 min. Bilateral surface electromyography (EMG) from the SCM and SC was recorded, and the onset time and the average rectified value of the EMG signal was determined for epochs of 100 ms; starting 100 ms prior to and 500 ms after the perturbation onset. Individuals with NP, as compared to HC, demonstrated delayed onset times and reduced EMG amplitude of the SCM and SC muscles in response to all postural perturbations. Such findings were most pronounced following the FS postural perturbation (healthy vs. NP for SCM 83.3 ± 8.0 vs. 86.3 ± 4.4 and SC 75.6 ± 3.5 vs. 89.3 ± 4.2), which was also associated with the greatest change (expressed in % relative to baseline) in EMG amplitude (healthy vs. NP for SCM 206.6 ± 50.4 vs. 115.9 ± 15.7 and SC 83.4 ± 19.2 vs. 69.2 ± 10.9) across all postural perturbations types. Individuals with NP display altered neural control of the neck musculature in response to rapid, unanticipated full body postural perturbations. Although the relative timing of neck musculature activity in individuals with NP appears to be intact, simultaneous co-activation of the neck musculature emerges for unanticipated anterior-posterior postural perturbations. PMID:24632836

  13. Brain Activity during Lower-Limb Movement with Manual Facilitation: An fMRI Study

    PubMed Central

    de Almeida, Patrícia Maria Duarte; Vieira, Ana Isabel Correia Matos de Ferreira; Canário, Nádia Isabel Silva; Castelo-Branco, Miguel; de Castro Caldas, Alexandre Lemos

    2015-01-01

    Brain activity knowledge of healthy subjects is an important reference in the context of motor control and reeducation. While the normal brain behavior for upper-limb motor control has been widely explored, the same is not true for lower-limb control. Also the effects that different stimuli can evoke on movement and respective brain activity are important in the context of motor potentialization and reeducation. For a better understanding of these processes, a functional magnetic resonance imaging (fMRI) was used to collect data of 10 healthy subjects performing lower-limb multijoint functional movement under three stimuli: verbal stimulus, manual facilitation, and verbal + manual facilitation. Results showed that, with verbal stimulus, both lower limbs elicit bilateral cortical brain activation; with manual facilitation, only the left lower limb (LLL) elicits bilateral activation while the right lower limb (RLL) elicits contralateral activation; verbal + manual facilitation elicits bilateral activation for the LLL and contralateral activation for the RLL. Manual facilitation also elicits subcortical activation in white matter, the thalamus, pons, and cerebellum. Deactivations were also found for lower-limb movement. Manual facilitation is stimulus capable of generating brain activity in healthy subjects. Stimuli need to be specific for bilateral activation and regarding which brain areas we aim to activate. PMID:25722890

  14. Consistent abnormalities in metabolic network activity in idiopathic rapid eye movement sleep behaviour disorder

    PubMed Central

    Wu, Ping; Yu, Huan; Peng, Shichun; Dauvilliers, Yves; Wang, Jian; Ge, Jingjie; Zhang, Huiwei; Eidelberg, David

    2014-01-01

    Rapid eye movement sleep behaviour disorder has been evaluated using Parkinson’s disease-related metabolic network. It is unknown whether this disorder is itself associated with a unique metabolic network. 18F-fluorodeoxyglucose positron emission tomography was performed in 21 patients (age 65.0 ± 5.6 years) with idiopathic rapid eye movement sleep behaviour disorder and 21 age/gender-matched healthy control subjects (age 62.5 ± 7.5 years) to identify a disease-related pattern and examine its evolution in 21 hemi-parkinsonian patients (age 62.6 ± 5.0 years) and 16 moderate parkinsonian patients (age 56.9 ± 12.2 years). We identified a rapid eye movement sleep behaviour disorder-related metabolic network characterized by increased activity in pons, thalamus, medial frontal and sensorimotor areas, hippocampus, supramarginal and inferior temporal gyri, and posterior cerebellum, with decreased activity in occipital and superior temporal regions. Compared to the healthy control subjects, network expressions were elevated (P < 0.0001) in the patients with this disorder and in the parkinsonian cohorts but decreased with disease progression. Parkinson’s disease-related network activity was also elevated (P < 0.0001) in the patients with rapid eye movement sleep behaviour disorder but lower than in the hemi-parkinsonian cohort. Abnormal metabolic networks may provide markers of idiopathic rapid eye movement sleep behaviour disorder to identify those at higher risk to develop neurodegenerative parkinsonism. PMID:25338949

  15. Direction-dependent activation of the insular cortex during vertical and horizontal hand movements.

    PubMed

    Rousseau, C; Fautrelle, L; Papaxanthis, C; Fadiga, L; Pozzo, T; White, O

    2016-06-14

    The planning of any motor action requires a complex multisensory processing by the brain. Gravity - immutable on Earth - has been shown to be a key input to these mechanisms. Seminal fMRI studies performed during visual perception of falling objects and self-motion demonstrated that humans represent the action of gravity in parts of the cortical vestibular system; in particular, the insular cortex and the cerebellum. However, little is known as to whether a specific neural network is engaged when processing non-visual signals relevant to gravity. We asked participants to perform vertical and horizontal hand movements without visual control, while lying in a 3T-MRI scanner. We highlighted brain regions activated in the processing of vertical movements, for which the effects of gravity changed during execution. Precisely, the left insula was activated in vertical movements and not in horizontal movements. Moreover, the network identified by contrasting vertical and horizontal movements overlapped with neural correlates previously associated to the processing of simulated self-motion and visual perception of the vertical direction. Interestingly, we found that the insular cortex activity is direction-dependent which suggests that this brain region processes the effects of gravity on the moving limbs through non-visual signals. PMID:27001175

  16. The relationship between adolescents' physical activity, fundamental movement skills and weight status.

    PubMed

    O' Brien, Wesley; Belton, Sarahjane; Issartel, Johann

    2016-06-01

    The aim of this study was to determine if a potential relationship among physical activity (PA), fundamental movement skills and weight status exists amongst early adolescent youth. Participants were a sample of 85 students; 54 boys (mean age = 12.94 ± 0.33 years) and 31 girls (mean age = 12.75 ± 0.43 years). Data gathered during physical education class included PA (accelerometry), fundamental movement skills and anthropometric measurements. Standard multiple regression revealed that PA and total fundamental movement skill proficiency scores explained 16.5% (P < 0.001) of the variance in the prediction of body mass index. Chi-square tests for independence further indicated that compared with overweight or obese adolescents, a significantly higher proportion of adolescents classified as normal weight achieved mastery/near-mastery in fundamental movement skills. Results from the current investigation indicate that weight status is an important correlate of fundamental movement skill proficiency during adolescence. Aligned with most recent research, school- and community-based programmes that include developmentally structured learning experiences delivered by specialists can significantly improve fundamental movement skill proficiency in youth. PMID:26437119

  17. Firing behavior of vestibular neurons during active and passive head movements: vestibulo-spinal and other non-eye-movement related neurons

    NASA Technical Reports Server (NTRS)

    McCrea, R. A.; Gdowski, G. T.; Boyle, R.; Belton, T.; Peterson, B. W. (Principal Investigator)

    1999-01-01

    The firing behavior of 51 non-eye movement related central vestibular neurons that were sensitive to passive head rotation in the plane of the horizontal semicircular canal was studied in three squirrel monkeys whose heads were free to move in the horizontal plane. Unit sensitivity to active head movements during spontaneous gaze saccades was compared with sensitivity to passive head rotation. Most units (29/35 tested) were activated at monosynaptic latencies following electrical stimulation of the ipsilateral vestibular nerve. Nine were vestibulo-spinal units that were antidromically activated following electrical stimulation of the ventromedial funiculi of the spinal cord at C1. All of the units were less sensitive to active head movements than to passive whole body rotation. In the majority of cells (37/51, 73%), including all nine identified vestibulo-spinal units, the vestibular signals related to active head movements were canceled. The remaining units (n = 14, 27%) were sensitive to active head movements, but their responses were attenuated by 20-75%. Most units were nearly as sensitive to passive head-on-trunk rotation as they were to whole body rotation; this suggests that vestibular signals related to active head movements were cancelled primarily by subtraction of a head movement efference copy signal. The sensitivity of most units to passive whole body rotation was unchanged during gaze saccades. A fundamental feature of sensory processing is the ability to distinguish between self-generated and externally induced sensory events. Our observations suggest that the distinction is made at an early stage of processing in the vestibular system.

  18. Precise Control of Movement Kinematics by Optogenetic Inhibition of Purkinje Cell Activity

    PubMed Central

    Heiney, Shane A.; Kim, Jinsook; Augustine, George J.

    2014-01-01

    Purkinje cells (PCs) of the cerebellar cortex are necessary for controlling movement with precision, but a mechanistic explanation of how the activity of these inhibitory neurons regulates motor output is still lacking. We used an optogenetic approach in awake mice to show for the first time that transiently suppressing spontaneous activity in a population of PCs is sufficient to cause discrete movements that can be systematically modulated in size, speed, and timing depending on how much and how long PC firing is suppressed. We further demonstrate that this fine control of movement kinematics is mediated by a graded disinhibition of target neurons in the deep cerebellar nuclei. Our results prove a long-standing model of cerebellar function and provide the first demonstration that suppression of inhibitory signals can act as a powerful mechanism for the precise control of behavior. PMID:24501371

  19. Lateralization of brain activity pattern during unilateral movement in Parkinson's disease.

    PubMed

    Wu, Tao; Hou, Yanan; Hallett, Mark; Zhang, Jiarong; Chan, Piu

    2015-05-01

    We investigated the lateralization of brain activity pattern during performance of unilateral movement in drug-naïve Parkinson's disease (PD) patients with only right hemiparkinsonian symptoms. Functional MRI was obtained when the subjects performed strictly unilateral right hand movement. A laterality index was calculated to examine the lateralization. Patients had decreased activity in the left putamen and left supplementary motor area, but had increased activity in the right primary motor cortex, right premotor cortex, left postcentral gyrus, and bilateral cerebellum. The laterality index was significantly decreased in PD patients compared with controls (0.41 ± 0.14 vs. 0.84 ± 0.09). The connectivity from the left putamen to cortical motor regions and cerebellum was decreased, while the interactions between the cortical motor regions, cerebellum, and right putamen were increased. Our study demonstrates that in early PD, the lateralization of brain activity during unilateral movement is significantly reduced. The dysfunction of the striatum-cortical circuit, decreased transcallosal inhibition, and compensatory efforts from cortical motor regions, cerebellum, and the less affected striatum are likely reasons contributing to the reduced motor lateralization. The disruption of the lateralized brain activity pattern might be a reason underlying some motor deficits in PD, like mirror movements or impaired bilateral motor coordination. PMID:25644527

  20. Neuromuscular control of the point to point and oscillatory movements of a sagittal arm with the actor-critic reinforcement learning method.

    PubMed

    Golkhou, Vahid; Parnianpour, Mohamad; Lucas, Caro

    2005-04-01

    In this study, we have used a single link system with a pair of muscles that are excited with alpha and gamma signals to achieve both point to point and oscillatory movements with variable amplitude and frequency.The system is highly nonlinear in all its physical and physiological attributes. The major physiological characteristics of this system are simultaneous activation of a pair of nonlinear muscle-like-actuators for control purposes, existence of nonlinear spindle-like sensors and Golgi tendon organ-like sensor, actions of gravity and external loading. Transmission delays are included in the afferent and efferent neural paths to account for a more accurate representation of the reflex loops.A reinforcement learning method with an actor-critic (AC) architecture instead of middle and low level of central nervous system (CNS), is used to track a desired trajectory. The actor in this structure is a two layer feedforward neural network and the critic is a model of the cerebellum. The critic is trained by state-action-reward-state-action (SARSA) method. The critic will train the actor by supervisory learning based on the prior experiences. Simulation studies of oscillatory movements based on the proposed algorithm demonstrate excellent tracking capability and after 280 epochs the RMS error for position and velocity profiles were 0.02, 0.04 rad and rad/s, respectively. PMID:16154874

  1. Mirrored, imagined and executed movements differentially activate sensorimotor cortex in amputees with and without phantom limb pain.

    PubMed

    Diers, Martin; Christmann, Christoph; Koeppe, Caroline; Ruf, Matthias; Flor, Herta

    2010-05-01

    Extended viewing of movements of the intact hand in a mirror as well as motor imagery has been shown to decrease pain in phantom pain patients. We used functional magnetic resonance imaging to assess the neural correlates of mirrored, imagined and executed hand movements in 14 upper extremity amputees - 7 with phantom limb pain (PLP) and 7 without phantom limb pain (non-PLP) and 9 healthy controls (HC). Executed movement activated the contralateral sensorimotor area in all three groups but ipsilateral cortex was only activated in the non-PLP and HC group. Mirrored movements activated the sensorimotor cortex contralateral to the hand seen in the mirror in the non-PLP and the HC but not in the PLP. Imagined movement activated the supplementary motor area in all groups and the contralateral primary sensorimotor cortex in the non-PLP and HC but not in the PLP. Mirror- and movement-related activation in the bilateral sensorimotor cortex in the mirror movement condition and activation in the sensorimotor cortex ipsilateral to the moved hand in the executed movement condition were significantly negatively correlated with the magnitude of phantom limb pain in the amputee group. Further research must identify the causal mechanisms related to mirror treatment, imagined movements or movements of the other hand and associated changes in pain perception. PMID:20359825

  2. Self-organization in the movement activity of social insects (Hymenoptera: Formicidae)

    NASA Astrophysics Data System (ADS)

    Neves, Felipe Marcel; Pie, Marcio Roberto; Viana, Ricardo Luiz

    2012-09-01

    Social insects present behavioral, morphologic and social variation, which bring ideal situations to study emergent temporal-spatial patterns. In this study, we observe the self-organization in the movement activity of social insects in different species and densities. In our preliminary results, all the species observed present a pattern more complex in higher densities and with structural differences between them.

  3. Passive Joint Forces Are Tuned to Limb Use in Insects and Drive Movements without Motor Activity

    PubMed Central

    Ache, Jan M.; Matheson, Thomas

    2013-01-01

    Summary Background Limb movements are generally driven by active muscular contractions working with and against passive forces arising in muscles and other structures. In relatively heavy limbs, the effects of gravity and inertia predominate, whereas in lighter limbs, passive forces intrinsic to the limb are of greater consequence. The roles of passive forces generated by muscles and tendons are well understood, but there has been little recognition that forces originating within joints themselves may also be important, and less still that these joint forces may be adapted through evolution to complement active muscle forces acting at the same joint. Results We examined the roles of passive joint forces in insect legs with different arrangements of antagonist muscles. We first show that passive forces modify actively generated movements of a joint across its working range, and that they can be sufficiently strong to generate completely passive movements that are faster than active movements observed in natural behaviors. We further demonstrate that some of these forces originate within the joint itself. In legs of different species adapted to different uses (walking, jumping), these passive joint forces complement the balance of strength of the antagonist muscles acting on the joint. We show that passive joint forces are stronger where they assist the weaker of two antagonist muscles. Conclusions In limbs where the dictates of a key behavior produce asymmetry in muscle forces, passive joint forces can be coadapted to provide the balance needed for the effective generation of other behaviors. PMID:23871240

  4. Attending to Eye Movements and Retinal Eccentricity: Evidence for the Activity Distribution Model of Attention Reconsidered

    ERIC Educational Resources Information Center

    Turk-Browne, Nicholas B.; Pratt, Jay

    2005-01-01

    When testing between spotlight and activity distribution models of visual attention, D. LaBerge, R. L. Carlson, J. K. Williams, and B. G. Bunney (1997) used an experimental paradigm in which targets are embedded in 3 brief displays. This paradigm, however, may be confounded by retinal eccentricity effects and saccadic eye movements. When the…

  5. Social Media and the Idle No More Movement: Citizenship, Activism and Dissent in Canada

    ERIC Educational Resources Information Center

    Tupper, Jennifer

    2014-01-01

    This paper, informed by a critique of traditional understandings of citizenship and civic education, explores the use of social media as a means of fostering activism and dissent. Specifically, the paper explores the ways in which the Idle No More Movement, which began in Canada in 2012 marshalled social media to educate about and protest Bill…

  6. It's Your Move: Expressive Movement Activities for the Language Arts Class.

    ERIC Educational Resources Information Center

    Blatt, Gloria T.; Cunningham, Jean

    Noting that children can best respond to literature through the arts--drawing, acting, writing, or dancing--this book provides teachers with a variety of activities for developing and using physical movement in the context of the language arts and literature curricula in the elementary school. Following a brief introduction examining expressive…

  7. Does Weight Status Influence Associations between Children's Fundamental Movement Skills and Physical Activity?

    ERIC Educational Resources Information Center

    Hume, Clare; Okely, Anthony; Bagley, Sarah; Telford, Amanda; Booth, Michael; Crawford, David; Salmon, Jo

    2008-01-01

    This study sought to determine whether weight status influences the association among children's fundamental movement skills (FMS) and physical activity (PA). Two hundred forty-eight children ages 9-12 years participated. Proficiency in three object-control skills and two locomotor skills was examined. Accelerometers objectively assessed physical…

  8. Hand-Arm Coordinated Manipulation Using Active Body-Environment Contact

    NASA Astrophysics Data System (ADS)

    Sugaiwa, Taisuke; Iwata, Hiroyasu; Sugano, Shigeki

    Human-symbiotic humanoid robots that can perform tasks dexterously with their hands are needed in our homes, welfare facilities, and other places. To improve their performance of tasks, we propose a scheme of controlling motion aimed at appropriately coordinated hand and arm motions. By observing human manual tasks, we identify an active body-environment contact as a kind of human manual skills and devise a motion control scheme based on it. We also analyze the effectiveness of the combination of the active body-environment contact and our proposed scheme in example tasks of the adding/removing constraint task. We validate our motion control scheme through actual tests on a prototype human-symbiotic humanoid robot.

  9. Posture and Movement

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Session TP3 includes short reports on: (1) Modification of Goal-Directed Arm Movements During Inflight Adaptation to Microgravity; (2) Quantitative Analysis of Motion control in Long Term Microgravity; (3) Does the Centre of Gravity Remain the Stabilised Reference during Complex Human Postural Equilibrium Tasks in Weightlessness?; and (4) Arm End-Point Trajectories Under Normal and Microgravity Environments.

  10. Activation of the motor cortex during phasic rapid eye movement sleep.

    PubMed

    De Carli, Fabrizio; Proserpio, Paola; Morrone, Elisa; Sartori, Ivana; Ferrara, Michele; Gibbs, Steve Alex; De Gennaro, Luigi; Lo Russo, Giorgio; Nobili, Lino

    2016-02-01

    When dreaming during rapid eye movement (REM) sleep, we can perform complex motor behaviors while remaining motionless. How the motor cortex behaves during this state remains unknown. Here, using intracerebral electrodes sampling the human motor cortex in pharmacoresistant epileptic patients, we report a pattern of electroencephalographic activation during REM sleep similar to that observed during the performance of a voluntary movement during wakefulness. This pattern is present during phasic REM sleep but not during tonic REM sleep, the latter resembling relaxed wakefulness. This finding may help clarify certain phenomenological aspects observed in REM sleep behavior disorder. PMID:26575212

  11. Rapid eye movement-related brain activation in human sleep: a functional magnetic resonance imaging study.

    PubMed

    Wehrle, Renate; Czisch, Michael; Kaufmann, Christian; Wetter, Thomas C; Holsboer, Florian; Auer, Dorothee P; Pollmächer, Thomas

    2005-05-31

    In animal models, ponto-geniculo-occipital waves appear as an early sign of rapid eye movement sleep and may be functionally significant for brain plasticity processes. In this pilot study, we use a combined polysomnographic and functional magnetic resonance imaging approach, and show distinct magnetic resonance imaging signal increases in the posterior thalamus and occipital cortex in close temporal relationship to rapid eye movements during human rapid eye movement sleep. These findings are consistent with cell recordings in animal experiments and demonstrate that functional magnetic resonance imaging can be utilized to detect ponto-geniculo-occipital-like activity in humans. Studying intact neuronal networks underlying sleep regulation is no longer confined to animal models, but has been shown to be feasible in humans by a combined functional magnetic resonance imaging and electroencephalograph approach. PMID:15891584

  12. 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

  13. 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. PMID:26957762

  14. 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.

  15. Cells in the monkey ponto-medullary reticular formation modulate their activity with slow finger movements

    PubMed Central

    Soteropoulos, Demetris S; Williams, Elizabeth R; Baker, Stuart N

    2012-01-01

    Recent work has shown that the primate reticulospinal tract can influence spinal interneurons and motoneurons involved in control of the hand. However, demonstrating connectivity does not reveal whether reticular outputs are modulated during the control of different types of hand movement. Here, we investigated how single unit discharge in the pontomedullary reticular formation (PMRF) modulated during performance of a slow finger movement task in macaque monkeys. Two animals performed an index finger flexion–extension task to track a target presented on a computer screen; single units were recorded both from ipsilateral PMRF (115 cells) and contralateral primary motor cortex (M1, 210 cells). Cells in both areas modulated their activity with the task (M1: 87%, PMRF: 86%). Some cells (18/115 in PMRF; 96/210 in M1) received sensory input from the hand, showing a short-latency modulation in their discharge following a rapid passive extension movement of the index finger. Effects in ipsilateral electromyogram to trains of stimuli were recorded at 45 sites in the PMRF. These responses involved muscles controlling the digits in 13/45 sites (including intrinsic hand muscles, 5/45 sites). We conclude that PMRF may contribute to the control of fine finger movements, in addition to its established role in control of more proximal limb and trunk movements. This finding may be especially important in understanding functional recovery after brain lesions such as stroke. PMID:22641776

  16. Cells in the monkey ponto-medullary reticular formation modulate their activity with slow finger movements.

    PubMed

    Soteropoulos, Demetris S; Williams, Elizabeth R; Baker, Stuart N

    2012-08-15

    Recent work has shown that the primate reticulospinal tract can influence spinal interneurons and motoneurons involved in control of the hand. However, demonstrating connectivity does not reveal whether reticular outputs are modulated during the control of different types of hand movement. Here, we investigated how single unit discharge in the pontomedullary reticular formation (PMRF) modulated during performance of a slow finger movement task in macaque monkeys. Two animals performed an index finger flexion–extension task to track a target presented on a computer screen; single units were recorded both from ipsilateral PMRF (115 cells) and contralateral primary motor cortex (M1, 210 cells). Cells in both areas modulated their activity with the task (M1: 87%, PMRF: 86%). Some cells (18/115 in PMRF; 96/210 in M1) received sensory input from the hand, showing a short-latency modulation in their discharge following a rapid passive extension movement of the index finger. Effects in ipsilateral electromyogram to trains of stimuli were recorded at 45 sites in the PMRF. These responses involved muscles controlling the digits in 13/45 sites (including intrinsic hand muscles, 5/45 sites). We conclude that PMRF may contribute to the control of fine finger movements, in addition to its established role in control of more proximal limb and trunk movements. This finding may be especially important in understanding functional recovery after brain lesions such as stroke. PMID:22641776

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

    PubMed Central

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

    2016-01-01

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

  18. Eye Movements during Auditory Attention Predict Individual Differences in Dorsal Attention Network Activity

    PubMed Central

    Braga, Rodrigo M.; Fu, Richard Z.; Seemungal, Barry M.; Wise, Richard J. S.; Leech, Robert

    2016-01-01

    The neural mechanisms supporting auditory attention are not fully understood. A dorsal frontoparietal network of brain regions is thought to mediate the spatial orienting of attention across all sensory modalities. Key parts of this network, the frontal eye fields (FEF) and the superior parietal lobes (SPL), contain retinotopic maps and elicit saccades when stimulated. This suggests that their recruitment during auditory attention might reflect crossmodal oculomotor processes; however this has not been confirmed experimentally. Here we investigate whether task-evoked eye movements during an auditory task can predict the magnitude of activity within the dorsal frontoparietal network. A spatial and non-spatial listening task was used with on-line eye-tracking and functional magnetic resonance imaging (fMRI). No visual stimuli or cues were used. The auditory task elicited systematic eye movements, with saccade rate and gaze position predicting attentional engagement and the cued sound location, respectively. Activity associated with these separate aspects of evoked eye-movements dissociated between the SPL and FEF. However these observed eye movements could not account for all the activation in the frontoparietal network. Our results suggest that the recruitment of the SPL and FEF during attentive listening reflects, at least partly, overt crossmodal oculomotor processes during non-visual attention. Further work is needed to establish whether the network’s remaining contribution to auditory attention is through covert crossmodal processes, or is directly involved in the manipulation of auditory information. PMID:27242465

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

    PubMed

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

    2014-01-01

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

  20. 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

  1. CCL21/IL21-armed oncolytic adenovirus enhances antitumor activity against TERT-positive tumor cells.

    PubMed

    Li, Yang; Li, Yi-Fei; Si, Chong-Zhan; Zhu, Yu-Hui; Jin, Yan; Zhu, Tong-Tong; Liu, Ming-Yuan; Liu, Guang-Yao

    2016-07-15

    Multigene-armed oncolytic adenoviruses are capable of efficiently generating a productive antitumor immune response. The chemokine (C-C motif) ligand 21 (CCL21) binds to CCR7 on naïve T cells and dendritic cells (DCs) to promote their chemoattraction to the tumor and resultant antitumor activity. Interleukin 21 (IL21) promotes survival of naïve T cells while maintaining their CCR7 surface expression, which increases their capacity to transmigrate in response to CCL21 chemoattraction. IL21 is also involved in NK cell differentiation and B cell activation and proliferation. The generation of effective antitumor immune responses is a complex process dependent upon coordinated interactions of various subsets of effector cells. Using the AdEasy system, we aimed to construct an oncolytic adenovirus co-expressing CCL21 and IL21 that could selectively replicate in TERTp-positive tumor cells (Ad-CCL21-IL21 virus). The E1A promoter of these oncolytic adenoviruses was replaced by telomerase reverse transcriptase promoter (TERTp). Ad-CCL21-IL21 was constructed from three plasmids, pGTE-IL21, pShuttle-CMV-CCL21 and AdEasy-1 and was homologously recombined and propagated in the Escherichia coli strain BJ5183 and the packaging cell line HEK-293, respectively. Our results showed that our targeted and armed oncolytic adenoviruses Ad-CCL21-IL21 can induce apoptosis in TERTp-positive tumor cells to give rise to viral propagation, in a dose-dependent manner. Importantly, we confirm that these modified oncolytic adenoviruses do not replicate efficiently in normal cells even under high viral loads. Additionally, we investigate the role of Ad-CCL21-IL21 in inducing antitumor activity and tumor specific cytotoxicity of CTLs in vitro. This study suggests that Ad-CCL21-IL21 is a promising targeted tumor-specific oncolytic adenovirus. PMID:27157859

  2. Mirroring activity in the brain and movement determinant in the Rorschach test.

    PubMed

    Porcelli, Piero; Giromini, Luciano; Parolin, Laura; Pineda, Jaime A; Viglione, Donald J

    2013-01-01

    Human movement (M) responses to the Rorschach are related to cognitive sophistication, creativity, and empathy. Recent studies also link Ms to EEG-mu suppression, an index of mirroring activity in the brain. In this article, we further investigate the link between Ms and mu suppression by testing some clinical interpretative distinctions. Previously collected EEG data recorded during the administration of the Rorschach were reanalyzed. We hypothesized that (a) among several responses investigated, only M would be associated with mu suppression, and (b) Ms with active movement, ordinary form quality, or whole human figures would be most strongly associated with mu suppression. Hypothesis 1 was fully confirmed, thus supporting that the traditional interpretation of M has a neurobiological foundation. Hypothesis 2 was partially confirmed; that is, active Ms were associated with mu suppression more strongly than passive Ms (p < .05), but no other significant differences emerged. Clinical implications are discussed. PMID:23495976

  3. Feature Selection in Classification of Eye Movements Using Electrooculography for Activity Recognition

    PubMed Central

    Mala, S.; Latha, K.

    2014-01-01

    Activity recognition is needed in different requisition, for example, reconnaissance system, patient monitoring, and human-computer interfaces. Feature selection plays an important role in activity recognition, data mining, and machine learning. In selecting subset of features, an efficient evolutionary algorithm Differential Evolution (DE), a very efficient optimizer, is used for finding informative features from eye movements using electrooculography (EOG). Many researchers use EOG signals in human-computer interactions with various computational intelligence methods to analyze eye movements. The proposed system involves analysis of EOG signals using clearness based features, minimum redundancy maximum relevance features, and Differential Evolution based features. This work concentrates more on the feature selection algorithm based on DE in order to improve the classification for faultless activity recognition. PMID:25574185

  4. Development of a Kinect Software Tool to Classify Movements during Active Video Gaming.

    PubMed

    Rosenberg, Michael; Thornton, Ashleigh L; Lay, Brendan S; Ward, Brodie; Nathan, David; Hunt, Daniel; Braham, Rebecca

    2016-01-01

    While it has been established that using full body motion to play active video games results in increased levels of energy expenditure, there is little information on the classification of human movement during active video game play in relationship to fundamental movement skills. The aim of this study was to validate software utilising Kinect sensor motion capture technology to recognise fundamental movement skills (FMS), during active video game play. Two human assessors rated jumping and side-stepping and these assessments were compared to the Kinect Action Recognition Tool (KART), to establish a level of agreement and determine the number of movements completed during five minutes of active video game play, for 43 children (m = 12 years 7 months ± 1 year 6 months). During five minutes of active video game play, inter-rater reliability, when examining the two human raters, was found to be higher for the jump (r = 0.94, p < .01) than the sidestep (r = 0.87, p < .01), although both were excellent. Excellent reliability was also found between human raters and the KART system for the jump (r = 0.84, p, .01) and moderate reliability for sidestep (r = 0.6983, p < .01) during game play, demonstrating that both humans and KART had higher agreement for jumps than sidesteps in the game play condition. The results of the study provide confidence that the Kinect sensor can be used to count the number of jumps and sidestep during five minutes of active video game play with a similar level of accuracy as human raters. However, in contrast to humans, the KART system required a fraction of the time to analyse and tabulate the results. PMID:27442437

  5. Development of a Kinect Software Tool to Classify Movements during Active Video Gaming

    PubMed Central

    Rosenberg, Michael; Lay, Brendan S.; Ward, Brodie; Nathan, David; Hunt, Daniel; Braham, Rebecca

    2016-01-01

    While it has been established that using full body motion to play active video games results in increased levels of energy expenditure, there is little information on the classification of human movement during active video game play in relationship to fundamental movement skills. The aim of this study was to validate software utilising Kinect sensor motion capture technology to recognise fundamental movement skills (FMS), during active video game play. Two human assessors rated jumping and side-stepping and these assessments were compared to the Kinect Action Recognition Tool (KART), to establish a level of agreement and determine the number of movements completed during five minutes of active video game play, for 43 children (m = 12 years 7 months ± 1 year 6 months). During five minutes of active video game play, inter-rater reliability, when examining the two human raters, was found to be higher for the jump (r = 0.94, p < .01) than the sidestep (r = 0.87, p < .01), although both were excellent. Excellent reliability was also found between human raters and the KART system for the jump (r = 0.84, p, .01) and moderate reliability for sidestep (r = 0.6983, p < .01) during game play, demonstrating that both humans and KART had higher agreement for jumps than sidesteps in the game play condition. The results of the study provide confidence that the Kinect sensor can be used to count the number of jumps and sidestep during five minutes of active video game play with a similar level of accuracy as human raters. However, in contrast to humans, the KART system required a fraction of the time to analyse and tabulate the results. PMID:27442437

  6. Movement of the Earth pole and the seismic activity in 2001-2012

    NASA Astrophysics Data System (ADS)

    Andreev, Aleksey; Zabbarova, Regina; Lapaeva, Valentina; Nefedyev, Yuri

    2014-05-01

    The relationship between the parameters which characterize the movement of the Earth pole and seismic activity are considered. The correlation of the considered parameters is studied. The discussions about the relationship of poles movement and irregularity in speed of Earth rotation with seismic activity were actively performed in 60- 70th years of last century. Mainly, the influence of seismicity on pole movement was considered in this works. In particular, the question about excitation of a pole by earthquakes chandler's fluctuations was studied. An interest in the similar researches continues till now. The chandler's movements investigations and their relation with rotation of the Earth and seismicity were proceeded. The correlation between appearance of earthquakes and abnormal evasion of time and latitude for the observatories located near an epicenter was also discussed. What changes in position of the Earth pole do occur as a result of the strongest earthquakes? To answer on this question it is necessary to study variations of "an average pole", where the basic periodic components in movement of a pole having amplitude 0.1"-0.3" are accepted. To perform the analysis of the pole co-ordinates (X and Y) the International service of the Earth rotation for 1995-2012 have been considered. Linear Orlov-Saharov transformation has been applied to an exception of the periodic movement. On the basis of this positions changes of an average pole (aperiodicity displacement and long periodical variations of an axis of rotation in a Earth body) have been calculated with an interval of 0.1 years. Was found the changes of position of an average pole of the Earth was preceded the most considerable seismic events of the beginning of 21 century. As a whole, the increase of seismic activity has begun after 2002 only. For example, there were 2 strong earthquakes with magnitude 7 and more (Salvador, India) in 2001 , 2 earthquakes (Tajikistan, Taiwan) occurred in 2002, and 5

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

    PubMed Central

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

    2012-01-01

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

  8. 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. PMID:25092272

  9. Enhanced activation of motor execution networks using action observation combined with imagination of lower limb movements.

    PubMed

    Villiger, Michael; Estévez, Natalia; Hepp-Reymond, Marie-Claude; Kiper, Daniel; Kollias, Spyros S; Eng, Kynan; Hotz-Boendermaker, Sabina

    2013-01-01

    The combination of first-person observation and motor imagery, i.e. first-person observation of limbs with online motor imagination, is commonly used in interactive 3D computer gaming and in some movie scenes. These scenarios are designed to induce a cognitive process in which a subject imagines himself/herself acting as the agent in the displayed movement situation. Despite the ubiquity of this type of interaction and its therapeutic potential, its relationship to passive observation and imitation during observation has not been directly studied using an interactive paradigm. In the present study we show activation resulting from observation, coupled with online imagination and with online imitation of a goal-directed lower limb movement using functional MRI (fMRI) in a mixed block/event-related design. Healthy volunteers viewed a video (first-person perspective) of a foot kicking a ball. They were instructed to observe-only the action (O), observe and simultaneously imagine performing the action (O-MI), or imitate the action (O-IMIT). We found that when O-MI was compared to O, activation was enhanced in the ventralpremotor cortex bilaterally, left inferior parietal lobule and left insula. The O-MI and O-IMIT conditions shared many activation foci in motor relevant areas as confirmed by conjunction analysis. These results show that (i) combining observation with motor imagery (O-MI) enhances activation compared to observation-only (O) in the relevant foot motor network and in regions responsible for attention, for control of goal-directed movements and for the awareness of causing an action, and (ii) it is possible to extensively activate the motor execution network using O-MI, even in the absence of overt movement. Our results may have implications for the development of novel virtual reality interactions for neurorehabilitation interventions and other applications involving training of motor tasks. PMID:24015241

  10. Enhanced Activation of Motor Execution Networks Using Action Observation Combined with Imagination of Lower Limb Movements

    PubMed Central

    Villiger, Michael; Estévez, Natalia; Hepp-Reymond, Marie-Claude; Kiper, Daniel; Kollias, Spyros S.; Eng, Kynan; Hotz-Boendermaker, Sabina

    2013-01-01

    The combination of first-person observation and motor imagery, i.e. first-person observation of limbs with online motor imagination, is commonly used in interactive 3D computer gaming and in some movie scenes. These scenarios are designed to induce a cognitive process in which a subject imagines himself/herself acting as the agent in the displayed movement situation. Despite the ubiquity of this type of interaction and its therapeutic potential, its relationship to passive observation and imitation during observation has not been directly studied using an interactive paradigm. In the present study we show activation resulting from observation, coupled with online imagination and with online imitation of a goal-directed lower limb movement using functional MRI (fMRI) in a mixed block/event-related design. Healthy volunteers viewed a video (first-person perspective) of a foot kicking a ball. They were instructed to observe-only the action (O), observe and simultaneously imagine performing the action (O-MI), or imitate the action (O-IMIT). We found that when O-MI was compared to O, activation was enhanced in the ventralpremotor cortex bilaterally, left inferior parietal lobule and left insula. The O-MI and O-IMIT conditions shared many activation foci in motor relevant areas as confirmed by conjunction analysis. These results show that (i) combining observation with motor imagery (O-MI) enhances activation compared to observation-only (O) in the relevant foot motor network and in regions responsible for attention, for control of goal-directed movements and for the awareness of causing an action, and (ii) it is possible to extensively activate the motor execution network using O-MI, even in the absence of overt movement. Our results may have implications for the development of novel virtual reality interactions for neurorehabilitation interventions and other applications involving training of motor tasks. PMID:24015241

  11. Comparison of laterality index of upper and lower limb movement using brain activated fMRI

    NASA Astrophysics Data System (ADS)

    Harirchian, Mohammad Hossein; Oghabian, Mohammad Ali; Rezvanizadeh, Alireza; Bolandzadeh, Niousha

    2008-03-01

    Asymmetry of bilateral cerebral function, i.e. laterality, is an important phenomenon in many brain actions such as motor functions. This asymmetry maybe altered in some clinical conditions such as Multiple Sclerosis (MS). The aim of this study was to delineate the laterality differences for upper and lower limbs in healthy subjects to compare this pattern with subjects suffering from MS in advance. Hence 9 Male healthy subjects underwent fMRI assessment, while they were asked to move their limbs in a predetermined pattern. The results showed that hands movement activates the brain with a significant lateralization in pre-motor cortex in comparison with lower limb. Also, dominant hands activate brain more lateralized than the non-dominant hand. In addition, Left basal ganglia were observed to be activated regardless of the hand used, While, These patterns of Brain activation was not detected in lower limbs. We hypothesize that this difference might be attributed to this point that hand is usually responsible for precise and fine voluntary movements, whereas lower limb joints are mainly responsible for locomotion, a function integrating voluntary and automatic bilateral movements.

  12. Adaptation to visual and proprioceptive rearrangement - Origin of the differential effectiveness of active and passive movements

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.

    1977-01-01

    Experiments were conducted to measure and compare the accuracy with which subjects pointed to visual targets before and after an exposure period in which they received systematic proprioceptive misinformation about the locations of visual targets. The crucial factor determining whether adaptation will be elicited is shown to be the presence of a discordance in the positional information being conveyed over two different sensory modalities. Another experiment was carried out to study the effectiveness of active and passive movements in eliciting adaptation when the subjects were exposed to a systematic discordance between the visual and proprioceptive locations of external targets without being permitted sight of their hands. Superiority of active over passive movements in producing adaptation to visual rearrangement is due to the greater accuracy of position sense information about voluntarily moved limbs, partly derived from the contribution of muscle afferent signals.

  13. Why do movements drift in the dark? Passive versus active mechanisms of error accumulation.

    PubMed

    Cameron, Brendan D; de la Malla, Cristina; López-Moliner, Joan

    2015-07-01

    When vision of the hand is unavailable, movements drift systematically away from their targets. It is unclear, however, why this drift occurs. We investigated whether drift is an active process, in which people deliberately modify their movements based on biased position estimates, causing the real hand to move away from the real target location, or a passive process, in which execution error accumulates because people have diminished sensory feedback and fail to adequately compensate for the execution error. In our study participants reached back and forth between two targets when vision of the hand, targets, or both the hand and targets was occluded. We observed the most drift when hand vision and target vision were occluded and equivalent amounts of drift when either hand vision or target vision was occluded. In a second experiment, we observed movement drift even when no visual target was ever present, providing evidence that drift is not driven by a visual-proprioceptive discrepancy. The observed drift in both experiments was consistent with a model of passive error accumulation in which the amount of drift is determined by the precision of the sensory estimate of movement error. PMID:25925317

  14. Movement Preparation and Bilateral Modulation of Beta Activity in Aging and Parkinson’s Disease

    PubMed Central

    Meziane, Hadj Boumediene; Moisello, Clara; Perfetti, Bernardo; Kvint, Svetlana; Isaias, Ioannis Ugo; Quartarone, Angelo; Di Rocco, Alessandro; Ghilardi, Maria Felice

    2015-01-01

    In previous studies of young subjects performing a reaction-time reaching task, we found that faster reaction times are associated with increased suppression of beta power over primary sensorimotor areas just before target presentation. Here we ascertain whether such beta decrease similarly occurs in normally aging subjects and also in patients with Parkinson’s disease (PD), where deficits in movement execution and abnormalities of beta power are usually present. We found that in both groups, beta power decreased during the motor task in the electrodes over the two primary sensorimotor areas. However, before target presentation, beta decreases in PD were significantly smaller over the right than over the left areas, while they were symmetrical in controls. In both groups, functional connectivity between the two regions, measured with imaginary coherence, increased before the target appearance; however, in PD, it decreased immediately after, while in controls, it remained elevated throughout motor planning. As in previous studies with young subjects, the degree of beta power before target appearance correlated with reaction time. The values of coherence during motor planning, instead, correlated with movement time, peak velocity and acceleration. We conclude that planning of prompt and fast movements partially depends on coordinated beta activity of both sensorimotor areas, already at the time of target presentation. The delayed onset of beta decreases over the right region observed in PD is possibly related to a decreased functional connectivity between the two areas, and this might account for deficits in force programming, movement duration and velocity modulation. PMID:25635777

  15. Relationships between fundamental movement skills and objectively measured physical activity in preschool children.

    PubMed

    Cliff, Dylan P; Okely, Anthony D; Smith, Leif M; McKeen, Kim

    2009-11-01

    Gender differences in cross-sectional relationships between fundamental movement skill (FMS) subdomains (locomotor skills, object-control skills) and physical activity were examined in preschool children. Forty-six 3- to 5-year-olds (25 boys) had their FMS video assessed (Test of Gross Motor Development II) and their physical activity objectively monitored (Actigraph 7164 accelerometers). Among boys, object-control skills were associated with physical activity and explained 16.9% (p = .024) and 13.7% (p = .049) of the variance in percent of time in moderate-to-vigorous physical activity (MVPA) and total physical activity, respectively, after controlling for age, SES and z-BMI. Locomotor skills were inversely associated with physical activity among girls, and explained 19.2% (p = .023) of the variance in percent of time in MVPA after controlling for confounders. Gender and FMS subdomain may influence the relationship between FMS and physical activity in preschool children. PMID:20128363

  16. Arm swing in human walking: what is their drive?

    PubMed

    Goudriaan, Marije; Jonkers, Ilse; van Dieen, Jaap H; Bruijn, Sjoerd M

    2014-06-01

    Although previous research has studied arm swing during walking, to date, it remains unclear what the contribution of passive dynamics versus active muscle control to arm swing is. In this study, we measured arm swing kinematics with 3D-motion analysis. We used a musculoskeletal model in OpenSim and generated dynamic simulations of walking with and without upper limb muscle excitations. We then compared arm swing amplitude and relative phase during both simulations to verify the extent to which passive dynamics contribute to arm swing. The results confirm that passive dynamics are partly responsible for arm swing during walking. However, without muscle activity, passive swing amplitude and relative phase decrease significantly (both p<0.05), the latter inducing a more in-phase swing pattern of the arms. Therefore, we conclude that muscle activity is needed to increase arm swing amplitude and modify relative phase during human walking to obtain an out-phase movement relative to the legs. PMID:24865637

  17. Effect of Tendon Vibration on Hemiparetic Arm Stability in Unstable Workspaces

    PubMed Central

    Conrad, Megan O.; Gadhoke, Bani; Scheidt, Robert A.; Schmit, Brian D.

    2015-01-01

    Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic arm. At the end of each movement, the robot applied destabilizing forces. During some trials, 70 Hz vibration was applied to the forearm flexor muscle tendons. 70 Hz was used as the stimulus frequency as it lies within the range of optimal frequencies that activate the muscle spindles at the highest response rate. Endpoint position, velocity, muscle activity and grip force data were compared before, during and after vibration. Stability at the endpoint was quantified as the magnitude of oscillation about the target position, calculated from the power of the tangential velocity data. Prior to vibration, subjects produced unstable, oscillating hand movements about the target location due to the applied force field. Stability increased during vibration, as evidenced by decreased oscillation in hand tangential velocity. PMID:26633892

  18. Effect of Tendon Vibration on Hemiparetic Arm Stability in Unstable Workspaces.

    PubMed

    Conrad, Megan O; Gadhoke, Bani; Scheidt, Robert A; Schmit, Brian D

    2015-01-01

    Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic arm. At the end of each movement, the robot applied destabilizing forces. During some trials, 70 Hz vibration was applied to the forearm flexor muscle tendons. 70 Hz was used as the stimulus frequency as it lies within the range of optimal frequencies that activate the muscle spindles at the highest response rate. Endpoint position, velocity, muscle activity and grip force data were compared before, during and after vibration. Stability at the endpoint was quantified as the magnitude of oscillation about the target position, calculated from the power of the tangential velocity data. Prior to vibration, subjects produced unstable, oscillating hand movements about the target location due to the applied force field. Stability increased during vibration, as evidenced by decreased oscillation in hand tangential velocity. PMID:26633892

  19. Changes in Cortical Activity During Real and Imagined Movements: an ERP Study

    PubMed Central

    Machado, Sergio; Arias-Carrión, Oscar; Paes, Flávia; Ribeiro, Pedro; Cagy, Mauricio; Piedade, Roberto; Almada, Leonardo Ferreira; Anghinah, Renato; Basile, Luis; Moro, Maria Francesca; Orsini, Marco; Silva, Julio Guilherme; Silva, Adriana Cardoso; Nardi, Antonio E.

    2013-01-01

    This study aims to compare the topographic distribution of cortical activation between real and imagined movement through event-related potential (ERP). We are specifically interested in identifying, the topographic distribution of activated areas, the intensity of activated areas, and the temporal occurrence of these activations on preparation and motor response phases. Twelve healthy and right handed subjects were instructed to perform a task under real and imagery conditions. The task was performed simultaneously to electroencephalographic (EEG) recording. When compared the conditions, we found a statistically significant difference in favor of real condition revealed by performing an unpaired t-test with multiple corrections of Bonferroni, demonstrating negative activity on electrode C3 and positive activity on the electrode C4 only in motor response phase. These findings revealed similar functional connections established during real and imagery conditions, suggesting that there are common neural substrate and similar properties of functional integration shared by conditions. PMID:24358049

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  2. Differential effects of mental load on proximal and distal arm muscle activity.

    PubMed

    Bloemsaat, Jules G; Meulenbroek, Ruud G J; Van Galen, Gerard P

    2005-12-01

    Work-related upper extremity disorders (WRUEDs) that result from keyboarding tasks are prevalent and costly. Although the precise mechanisms causing the disorder are not yet fully understood, several risk factors have been proposed. These include the repetitive nature of the motor task and the associated sustained static working postures, but also more psychological factors such as mental load. Epidemiological surveys have shown that WRUEDs are more prone to develop in the postural muscles of the neck/shoulder area than in the executive muscles controlling the hand. The present study investigated whether the activation patterns of these two muscle types are differentially affected by an additional mental load during the performance of a repetitive tapping task. Participants tapped various keying patterns with their dominant index finger at two prescribed tempi. Mental load was manipulated by means of an auditory short-term memory task. We recorded the EMG activity of two neck/shoulder muscles (trapezius and deltoid), two upper arm muscles (biceps and triceps), and four forearm muscles (flexor digitorum superficialis, extensor digitorum, extensor carpi radialis longus and extensor carpi ulnaris) and analyzed the kinematics and impact forces of the index finger. The results confirmed that the upper limb has two functions. Specifically, activity of the executive distal musculature was increased during tapping at the higher pace, while the activity of the postural upper limb musculature was elevated due to the memory task. We argue that continuously increased muscular activity can lead to fatigue and thus eventually cause musculoskeletal complaints. The results are discussed with respect to biomechanical adaptation strategies that deal with the consequences of increased noise in the neuromotor system due to enhanced mental processing. PMID:16078028

  3. Activation of Visuomotor Systems during Visually Guided Movements: A Functional MRI Study

    NASA Astrophysics Data System (ADS)

    Ellermann, Jutta M.; Siegal, Joel D.; Strupp, John P.; Ebner, Timothy J.; Ugurbil, Kâmil

    1998-04-01

    The dorsal stream is a dominant visuomotor pathway that connects the striate and extrastriate cortices to posterior parietal areas. In turn, the posterior parietal areas send projections to the frontal primary motor and premotor areas. This cortical pathway is hypothesized to be involved in the transformation of a visual input into the appropriate motor output. In this study we used functional magnetic resonance imaging (fMRI) of the entire brain to determine the patterns of activation that occurred while subjects performed a visually guided motor task. In nine human subjects, fMRI data were acquired on a 4-T whole-body MR system equipped with a head gradient coil and a birdcage RF coil using aT*2-weighted EPI sequence. Functional activation was determined for three different tasks: (1) a visuomotor task consisting of moving a cursor on a screen with a joystick in relation to various targets, (2) a hand movement task consisting of moving the joystick without visual input, and (3) a eye movement task consisting of moving the eyes alone without visual input. Blood oxygenation level-dependent (BOLD) contrast-based activation maps of each subject were generated using period cross-correlation statistics. Subsequently, each subject's brain was normalized to Talairach coordinates, and the individual maps were compared on a pixel by pixel basis. Significantly activated pixels common to at least four out of six subjects were retained to construct the final functional image. The pattern of activation during visually guided movements was consistent with the flow of information from striate and extrastriate visual areas, to the posterior parietal complex, and then to frontal motor areas. The extensive activation of this network and the reproducibility among subjects is consistent with a role for the dorsal stream in transforming visual information into motor behavior. Also extensively activated were the medial and lateral cerebellar structures, implicating the cortico

  4. The Actively Caring for People Movement at Virginia Tech and Beyond: Cultivating Compassion and Relationships in Residence Halls

    ERIC Educational Resources Information Center

    McCarty, Shane M.; Mullins, Taris G.; Geller, E. Scott; Shushok, Frank, Jr.

    2013-01-01

    A professor and a group of student leaders initiated the Actively Caring for People (AC4P) Movement to establish a more civil, compassionate, and inclusive culture by inspiring intentional acts of kindness. This article explores the AC4P Movement in a first-year residence hall at Virginia Tech and a second-year residence hall at University of…

  5. Active-Arm Passive-Leg Exercise Improves Cardiovascular Function in Spinal Cord Injury.

    PubMed

    West, Christopher R; Currie, Katharine D; Gee, Cameron; Krassioukov, Andrei V; Borisoff, Jaimie

    2015-11-01

    In a 43-yr-old male subject with a chronic T3 AIS A spinal cord injury, the acute cardiorespiratory responses to active upper-extremity exercise alone and combined active-arm passive-leg exercise (AAPLE) were investigated, along with the cardiorespiratory, cardiac, vascular, and body composition responses to a 6-wk AAPLE interval training intervention. AAPLE elicited superior acute maximal cardiorespiratory responses compared with upper-extremity exercise alone. In response to a 6-wk interval training regimen, AAPLE caused a 25% increase in peak oxygen uptake, a 10% increase in resting stroke volume, and a 4-fold increase in brachial artery blood flow. Conversely, there were no changes in femoral arterial function, body composition, or bone mineral density in response to training. As a potential clinical intervention, AAPLE may be advantageous over other forms of currently available exercise, owing to the minimal setup time and cost involved and the nonreliance on specialized equipment that is required for other exercise modalities. PMID:26259052

  6. Faster than their prey: new insights into the rapid movements of active carnivorous plants traps.

    PubMed

    Poppinga, Simon; Masselter, Tom; Speck, Thomas

    2013-07-01

    Plants move in very different ways and for different reasons, but some active carnivorous plants perform extraordinary motion: Their snap-, catapult- and suction traps perform very fast and spectacular motions to catch their prey after receiving mechanical stimuli. Numerous investigations have led to deeper insights into the physiology and biomechanics of these trapping devices, but they are far from being fully understood. We review concisely how plant movements are classified and how they follow principles that bring together speed, actuation and architecture of the moving organ. In particular, we describe and discuss how carnivorous plants manage to execute fast motion. We address open questions and assess the prospects for future studies investigating potential universal mechanisms that could be the basis of key characteristic features in plant movement such as stimulus transduction, post-stimulatory mechanical answers, and organ formation. PMID:23613360

  7. Detecting the movement and spawning activity of bigheaded carps with environmental DNA

    USGS Publications Warehouse

    Erickson, Richard A.; Rees, Christopher B.; Coulter, Alison A.; Merkes, Christopher; McCalla, Sunnie; Touzinsky, Katherine F; Walleser, Liza R.; Goforth, Reuben R.; Amberg, Jon

    2016-01-01

    Bigheaded carps are invasive fishes threatening to invade the Great Lakes basin and establish spawning populations, and have been monitored using environmental DNA (eDNA). Not only does eDNA hold potential for detecting the presence of species, but may also allow for quantitative comparisons like relative abundance of species across time or space. We examined the relationships among bigheaded carp movement, hydrography, spawning and eDNA on the Wabash River, IN, USA. We found positive relationships between eDNA and movement and eDNA and hydrography. We did not find a relationship between eDNA and spawning activity in the form of drifting eggs. Our first finding demonstrates how eDNA may be used to monitor species abundance, whereas our second finding illustrates the need for additional research into eDNA methodologies. Current applications of eDNA are widespread, but the relatively new technology requires further refinement.

  8. Detecting the movement and spawning activity of bigheaded carps with environmental DNA.

    PubMed

    Erickson, Richard A; Rees, Christopher B; Coulter, Alison A; Merkes, Christopher M; McCalla, Sunnie G; Touzinsky, Katherine F; Walleser, Liza; Goforth, Reuben R; Amberg, Jon J

    2016-07-01

    Bigheaded carps are invasive fishes threatening to invade the Great Lakes basin and establish spawning populations, and have been monitored using environmental DNA (eDNA). Not only does eDNA hold potential for detecting the presence of species, but may also allow for quantitative comparisons like relative abundance of species across time or space. We examined the relationships among bigheaded carp movement, hydrography, spawning and eDNA on the Wabash River, IN, USA. We found positive relationships between eDNA and movement and eDNA and hydrography. We did not find a relationship between eDNA and spawning activity in the form of drifting eggs. Our first finding demonstrates how eDNA may be used to monitor species abundance, whereas our second finding illustrates the need for additional research into eDNA methodologies. Current applications of eDNA are widespread, but the relatively new technology requires further refinement. PMID:27087387

  9. Human activities recognition by head movement using partial recurrent neural network

    NASA Astrophysics Data System (ADS)

    Tan, Henry C. C.; Jia, Kui; De Silva, Liyanage C.

    2003-06-01

    Traditionally, human activities recognition has been achieved mainly by the statistical pattern recognition methods or the Hidden Markov Model (HMM). In this paper, we propose a novel use of the connectionist approach for the recognition of ten simple human activities: walking, sitting down, getting up, squatting down and standing up, in both lateral and frontal views, in an office environment. By means of tracking the head movement of the subjects over consecutive frames from a database of different color image sequences, and incorporating the Elman model of the partial recurrent neural network (RNN) that learns the sequential patterns of relative change of the head location in the images, the proposed system is able to robustly classify all the ten activities performed by unseen subjects from both sexes, of different race and physique, with a recognition rate as high as 92.5%. This demonstrates the potential of employing partial RNN to recognize complex activities in the increasingly popular human-activities-based applications.

  10. Differences in corticospinal excitability to the biceps brachii between arm cycling and tonic contraction are not evident at the immediate onset of movement.

    PubMed

    Forman, Davis A; Philpott, Devin T G; Button, Duane C; Power, Kevin E

    2016-08-01

    This is the first study to examine changes in corticospinal excitability to the biceps brachii during the onset of arm cycling from a resting position to a point when steady-state arm cycling was obtained. Supraspinal and spinal excitability were assessed using motor-evoked potentials (MEPs) elicited via transcranial magnetic stimulation and cervicomedullary evoked potentials (CMEPs) elicited via transmastoid electrical stimulation, respectively. Evoked responses were recorded from the biceps brachii during elbow flexion (6 o'clock relative to a clock face) for both arm cycling and an intensity-matched tonic contraction at three separate periods: (1) immediately at the onset of motor output and after completion of the (2) 4th revolution and (3) 9th revolution. There was no difference during initiation between tasks for MEP (P = 0.79) or CMEP amplitudes (P = 0.57). However, MEP amplitudes were significantly larger during arm cycling than an intensity-matched tonic contraction after the completion of the 4th (Cycling 76.48 ± 17.35 % of M max, Tonic 63.45 ± 18.45 % of M max, P < 0.05) and 9th revolutions (Cycling 72.37 ± 15.96 % of M max, Tonic 58.1 ± 24.23 % of M max, P < 0.05). There were no differences between conditions in CMEP amplitudes at the 4th (Cycling 49.6 ± 25.4 % of M max, Tonic 41.6 ± 11.2 % of M max, P = 0.31) or the 9th revolution (Cycling 47.2 ± 17.0 % of M max, Tonic 40.8 ± 13.6 % of M max, P = 0.29). These results demonstrate that corticospinal excitability is not different between arm cycling and a tonic contraction at motor output onset, but supraspinal excitability is enhanced during steady-state arm cycling. This suggests a similarity in the way the corticospinal tract initiates motor outputs in humans, regardless of the differences that present themselves in the later, steady-state stages. PMID:27038204

  11. The Pediatric Motor Activity Log-Revised: Assessing Real-world Arm Use in Children with Cerebral Palsy

    PubMed Central

    Uswatte, Gitendra; Taub, Edward; Griffin, Angi; Vogtle, Laura; Rowe, Jan; Barman, Joydip

    2012-01-01

    Objective Widely accepted models of disability suggest that actual use of an impaired upper-extremity in everyday life frequently deviates from its motor capacity, as measured by laboratory tests. Yet, direct measures of real-world use of an impaired upper-extremity are rare in pediatric neurorehabilitation. This paper examines how well the Pediatric Motor Activity Log-Revised (PMAL-R) measures this parameter, when the PMAL-R is administered as a structured interview as originally designed. Design Parents of sixty children between 2–8 years with upper-extremity hemiparesis due to cerebral palsy (CP) completed the PMAL-R twice. Additionally, the children were videotaped during play structured to elicit spontaneous arm use. More-affected arm use was scored by masked raters; it was thought to reflect everyday activity since no cues were given about which arm to employ. Testing sessions were separated by 3 weeks, during which 29 children received upper-extremity rehabilitation and 31 did not. Results The PMAL-R had high internal consistency (Cronbach's α = .93) and test-retest reliability (r = .89). Convergent validity was supported by a strong correlation between changes in PMAL-R scores and more-affected arm use during play, r(53) = .5, p < .001. Conclusions The PMAL-R interview is a reliable and valid measure of upper-extremity pediatric neurorehabilitation outcome. PMID:22686553

  12. How vertical hand movements impact brain activity elicited by literally and metaphorically related words: an ERP study of embodied metaphor

    PubMed Central

    Bardolph, Megan; Coulson, Seana

    2014-01-01

    Embodied metaphor theory suggests abstract concepts are metaphorically linked to more experientially basic ones and recruit sensorimotor cortex for their comprehension. To test whether words associated with spatial attributes reactivate traces in sensorimotor cortex, we recorded EEG from the scalp of healthy adults as they read words while performing a concurrent task involving either upward- or downward- directed arm movements. ERPs were time-locked to words associated with vertical space—either literally (ascend, descend) or metaphorically (inspire, defeat)—as participants made vertical movements that were either congruent or incongruent with the words. Congruency effects emerged 200–300 ms after word onset for literal words, but not until after 500 ms post-onset for metaphorically related words. Results argue against a strong version of embodied metaphor theory, but support a role for sensorimotor simulation in concrete language. PMID:25566041

  13. A method to quantify movement activity of groups of animals using automated image analysis

    NASA Astrophysics Data System (ADS)

    Xu, Jianyu; Yu, Haizhen; Liu, Ying

    2009-07-01

    Most physiological and environmental changes are capable of inducing variations in animal behavior. The behavioral parameters have the possibility to be measured continuously in-situ by a non-invasive and non-contact approach, and have the potential to be used in the actual productions to predict stress conditions. Most vertebrates tend to live in groups, herds, flocks, shoals, bands, packs of conspecific individuals. Under culture conditions, the livestock or fish are in groups and interact on each other, so the aggregate behavior of the group should be studied rather than that of individuals. This paper presents a method to calculate the movement speed of a group of animal in a enclosure or a tank denoted by body length speed that correspond to group activity using computer vision technique. Frame sequences captured at special time interval were subtracted in pairs after image segmentation and identification. By labeling components caused by object movement in difference frame, the projected area caused by the movement of every object in the capture interval was calculated; this projected area was divided by the projected area of every object in the later frame to get body length moving distance of each object, and further could obtain the relative body length speed. The average speed of all object can well respond to the activity of the group. The group activity of a tilapia (Oreochromis niloticus) school to high (2.65 mg/L) levels of unionized ammonia (UIA) concentration were quantified based on these methods. High UIA level condition elicited a marked increase in school activity at the first hour (P<0.05) exhibiting an avoidance reaction (trying to flee from high UIA condition), and then decreased gradually.

  14. Single-neuron activity and eye movements during human REM sleep and awake vision.

    PubMed

    Andrillon, Thomas; Nir, Yuval; Cirelli, Chiara; Tononi, Giulio; Fried, Itzhak

    2015-01-01

    Are rapid eye movements (REMs) in sleep associated with visual-like activity, as during wakefulness? Here we examine single-unit activities (n=2,057) and intracranial electroencephalography across the human medial temporal lobe (MTL) and neocortex during sleep and wakefulness, and during visual stimulation with fixation. During sleep and wakefulness, REM onsets are associated with distinct intracranial potentials, reminiscent of ponto-geniculate-occipital waves. Individual neurons, especially in the MTL, exhibit reduced firing rates before REMs as well as transient increases in firing rate immediately after, similar to activity patterns observed upon image presentation during fixation without eye movements. Moreover, the selectivity of individual units is correlated with their response latency, such that units activated after a small number of images or REMs exhibit delayed increases in firing rates. Finally, the phase of theta oscillations is similarly reset following REMs in sleep and wakefulness, and after controlled visual stimulation. Our results suggest that REMs during sleep rearrange discrete epochs of visual-like processing as during wakefulness. PMID:26262924

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

  16. Single-neuron activity and eye movements during human REM sleep and awake vision

    PubMed Central

    Andrillon, Thomas; Nir, Yuval; Cirelli, Chiara; Tononi, Giulio; Fried, Itzhak

    2015-01-01

    Are rapid eye movements (REMs) in sleep associated with visual-like activity, as during wakefulness? Here we examine single-unit activities (n=2,057) and intracranial electroencephalography across the human medial temporal lobe (MTL) and neocortex during sleep and wakefulness, and during visual stimulation with fixation. During sleep and wakefulness, REM onsets are associated with distinct intracranial potentials, reminiscent of ponto-geniculate-occipital waves. Individual neurons, especially in the MTL, exhibit reduced firing rates before REMs as well as transient increases in firing rate immediately after, similar to activity patterns observed upon image presentation during fixation without eye movements. Moreover, the selectivity of individual units is correlated with their response latency, such that units activated after a small number of images or REMs exhibit delayed increases in firing rates. Finally, the phase of theta oscillations is similarly reset following REMs in sleep and wakefulness, and after controlled visual stimulation. Our results suggest that REMs during sleep rearrange discrete epochs of visual-like processing as during wakefulness. PMID:26262924

  17. Semi-circular microgrooves to observe active movements of individual Navicula pavillardii cells.

    PubMed

    Umemura, Kazuo; Haneda, Takahiro; Tanabe, Masashi; Suzuki, Akira; Kumashiro, Yoshikazu; Itoga, Kazuyoshi; Okano, Teruo; Mayama, Shigeki

    2013-03-01

    We performed a trajectory analysis of movements of Navicula pavillardii diatom cells that were confined to semi-circular microgrooves with several different curvature radii. Using the semi-circular micropattern, we succeeded in observing change of velocity of the same cell before and after the stimulation by N,N-dimethyl-p-toluidine (DMT). Because the looped grooves had longer contour length than straight grooves, it was effective to achieve the long term observation of the stimulated active cells. Although average velocity of 150 cells was significantly increased with DMT, the maximum velocity (19 μm/s) of the cells was not increased after the DMT injection. This may suggest that existence of the mechanical limit of the velocity of the diatom cells. Secondly, trajectories of individual cell movements along the walls of the semi-circular microgrooves were analyzed in detail. As a result, the velocity of the cells was not affected by the curvature radii of the grooves although the trajectories indicated an obvious restriction of area of the cell motion. This suggests that the surface of the diatom is effective in minimizing the frictional force between the cell body and the wall of a groove. Finally, a simple model of cell motion in the semi-circular groove was proposed to clarify the relationships among the forces that determine cell movement. PMID:23337812

  18. Measurement of the vestibulo-ocular reflex by magnetometry during active head movement.

    PubMed

    Aldren, C P; FitzGerald, J E; Kelly, P; Birchall, J P; Murray, A

    1996-10-01

    A new method of measuring the vestibulo-ocular reflex (VOR) during active head movements is presented. Subjects sat and attempted to maintain their gaze upon a fixed point whilst turning their heads from side to side in response to an auditory cue, to attain frequencies of head rotation that increased from 1 Hz to 4 Hz during a 24 s period. Head movements were monitored by a small magnetic field detector worn on the subject's forehead and positioned a set distance from a magnetic field transmitter coil. Eye movements were monitored using the corneo-retinal potential. Gain (eye angle/head angle) and phase difference (eye phase-head phase) were calculated to define the VOR. Three repeat measurements were made on 20 normal subjects. Gain decreased significantly (P < 0.0001) with increasing frequency whilst the phase difference remained unchanged. The 95% prediction intervals were narrow for both gain (+/- 0.28) and phase (+/- 11 degrees). These data, together with the speed and ease of performance of the test, suggest that the test can provide valuable information on the performance of the vestibular system. PMID:8922697

  19. Bacterial skin infections, active component, U.S. Armed Forces, 2000-2012.

    PubMed

    2013-12-01

    From 2000 through 2012, health care records of the Military Health System documented 998,671 incident cases of bacterial skin infections among active component members of the U.S. Armed Forces. Most cases (97.3%) were identified from records of outpatient medical encounters rather than hospitalizations. Cellulitis accounted for half (50.9%) of all cases of bacterial skin infection but 96 percent of associated hospital bed days. Of all cases, 42.3 percent were "other" skin infections (i.e., folliculitis, impetigo, pyoderma, pyogenic granuloma, other and unspecified infections). The remainder were attributable to carbuncles/furuncles (6.6%) and erysipelas (0.1%). Rates of infection were higher among female service members except for "other" skin infections. In general, the highest rates were associated with youth, recruit trainee status, and junior enlisted rank; however, rates of erysipelas were highest among those 50 years and older. Annual incidence rates of all bacterial skin infections have increased greatly since 2000. During the entire period, such infections required more than 1.4 million health care encounters and 94,000 hospital bed-days (equivalent to 257 years of lost duty time). The prevention, early diagnosis, and treatment of bacterial skin infections, particularly in high risk settings, deserve continued emphasis. PMID:24428536

  20. Post-Movement Beta Activity in Sensorimotor Cortex Indexes Confidence in the Estimations from Internal Models

    PubMed Central

    Wade, Cian; Brown, Peter

    2016-01-01

    Beta oscillations are a dominant feature of the sensorimotor system. A transient and prominent increase in beta oscillations is consistently observed across the sensorimotor cortical-basal ganglia network after cessation of voluntary movement: the post-movement beta synchronization (PMBS). Current theories about the function of the PMBS have been focused on either the closure of motor response or the processing of sensory afferance. Computational models of sensorimotor control have emphasized the importance of the integration between feedforward estimation and sensory feedback, and therefore the putative motor and sensory functions of beta oscillations may reciprocally interact with each other and in fact be indissociable. Here we show that the amplitude of sensorimotor PMBS is modulated by the history of visual feedback of task-relevant errors, and negatively correlated with the trial-to-trial exploratory adjustment in a sensorimotor adaptation task in young healthy human subjects. The PMBS also negatively correlated with the uncertainty associated with the feedforward estimation, which was recursively updated in light of new sensory feedback, as identified by a Bayesian learning model. These results reconcile the two opposing motor and sensory views of the function of PMBS, and suggest a unifying theory in which PMBS indexes the confidence in internal feedforward estimation in Bayesian sensorimotor integration. Its amplitude simultaneously reflects cortical sensory processing and signals the need for maintenance or adaptation of the motor output, and if necessary, exploration to identify an altered sensorimotor transformation. SIGNIFICANCE STATEMENT For optimal sensorimotor control, sensory feedback and feedforward estimation of a movement's sensory consequences should be weighted by the inverse of their corresponding uncertainties, which require recursive updating in a dynamic environment. We show that post-movement beta activity (13–30 Hz) over sensorimotor

  1. Neural co-activation as a yardstick of implicit motor learning and the propensity for conscious control of movement.

    PubMed

    Zhu, F F; Poolton, J M; Wilson, M R; Maxwell, J P; Masters, R S W

    2011-04-01

    Two studies examined EEG co-activation (coherence) between the verbal-analytical (T3) and motor planning (Fz) regions during a golf putting task. In Study 1, participants with a strong propensity to consciously monitor and control their movements, determined psychometrically by high scores on a movement specific Reinvestment Scale, displayed more alpha2 T3-Fz co-activation than participants with a weak propensity. In Study 2, participants who practiced a golf putting task implicitly (via an errorless learning protocol) displayed less alpha2 T3-Fz co-activation than those who practiced explicitly (by errorful learning). In addition, explicit but not implicit motor learners displayed more T3-Fz co-activation during golf putting under pressure, implying that verbal-analytical processing of putting movements increased under pressure. These findings provide neuropsychological evidence that supports claims that implicit motor learning can be used to limit movement specific reinvestment. PMID:21315795

  2. Active Ankle Movements Prevent Formation of Lower-Extremity Deep Venous Thrombosis After Orthopedic Surgery.

    PubMed

    Li, Ye; Guan, Xiang-Hong; Wang, Rui; Li, Bin; Ning, Bo; Su, Wei; Sun, Tao; Li, Hong-Yan

    2016-01-01

    BACKGROUND The aim of this study was to assess the preventive value of active ankle movements in the formation of lower-extremity deep venous thrombosis (DVT), attempting to develop a new method for rehabilitation nursing after orthopedic surgery. MATERIAL AND METHODS We randomly assigned 193 patients undergoing orthopedic surgery in the lower limbs into a case group (n=96) and a control group (n=97). The control group received routine nursing while the case group performed active ankle movements in addition to receiving routine nursing. Maximum venous outflow (MVO), maximum venous capacity (MVC), and blood rheology were measured and the incidence of DVT was recorded. RESULTS On the 11th and 14th days of the experiment, the case group had significantly higher MVO and MVC than the control group (all P<0.05). The whole-blood viscosity at high shear rate and the plasma viscosity were significantly lower in the case group than in the control group on the 14th day (both P<0.05). During the experiment, a significantly higher overall DVT incidence was recorded in the control group (8 with asymptomatic DVT) compared with the case group (1 with asymptomatic DVT) (P=0.034). During follow-up, the case group presented a significantly lower DVT incidence (1 with symptomatic DVT and 4 with asymptomatic DVT) than in the control group (5 with symptomatic DVT and 10 with asymptomatic DVT) (P=0.031). CONCLUSIONS Through increasing MVO and MVC and reducing blood rheology, active ankle movements may prevent the formation of lower-extremity DVT after orthopedic surgery. PMID:27600467

  3. Mass movements in fjords caused by seismic activity? A case study from Balsfjord, northern Norway.

    NASA Astrophysics Data System (ADS)

    Forwick, M.; Vorren, T. O.

    2003-04-01

    Fjords can provide excellent opportunities for investigating sedimentary processes related to slope failures. Balsfjord is a 46 km long and maximum 5 km wide fjord in northern Norway, about 10 km south of Tromsø. An end moraine divides the fjord into an Inner and Outer Basin. High-resolution seismic data (3.5 kHz penetration echo sounder), as well as two piston cores, one from each basin, were analysed. The objective of this study was to find submarine deposits that could be used to study the regionality and chronology of postglacial mass-movement activity in northern Norway. Various types of gravity flows were identified, i.e. slumps, debris flows and turbidites. Maximum thickness of one debris flow is c. 15 m. Two marked turbidites have a lateral extent of about 10 km. The origins of some slumps and debris flows include slope failure of the end moraine crossing the fjord, as well as in front of a river mouth. The origin of the turbidites will be studied using grain-size distribution. Three mass-movement events in both basins are correlated using radiocarbon dates. Since these events can be identified in both basins, they are suggested to indicate regional avalanche activity. The three events were bracketed between 9400 radiocarbon years BP and 9100 radiocarbon years BP. This time span fits into the period of most rapid postglacial isostatic uplift in areas adjacent to Balsfjord (Corner and Haugane, 1993). A close correlation between a steep uplift gradient and earthquake frequency/magnitude is suggested by several authors (e.g. Bøe et al., 2001). Thus, seismic activity can be regarded as a potential trigger mechanism for mass-movement activity in Balsfjord. References: Bøe, R., Hovland, M., Instanes, A., Rise, L. and Vasshus, S., 2000. Submarine slide scars and mass movements in Karmsundet and Skudenesfjorden, southwestern Norway: morphology and evolution. Marine Geology, 167(1-2): 147-165. Corner, G.D. and Haugane, E., 1993. Marine-lacustrine stratigraphy of

  4. Location of Instability During a Bench Press Alters Movement Patterns and Electromyographical Activity.

    PubMed

    Nairn, Brian C; Sutherland, Chad A; Drake, Janessa D M

    2015-11-01

    Instability training devices with the bench press exercise are becoming increasingly popular. Typically, the instability device is placed at the trunk/upper body (e.g., lying on a Swiss ball); however, a recent product called the Attitube has been developed, which places the location of instability at the hands by users lifting a water-filled tube. Therefore, the purpose of this study was to analyze the effects of different instability devices (location of instability) on kinematic and electromyographical patterns during the bench press exercise. Ten healthy males were recruited and performed 1 set of 3 repetitions for 3 different bench press conditions: Olympic bar on a stable bench (BENCH), Olympic bar on a stability ball (BALL), and Attitube on a stable bench (TUBE). The eccentric and concentric phases were analyzed in 10% intervals while electromyography was recorded from 24 electrode sites, and motion capture was used to track elbow flexion angle and 3-dimensional movement trajectories and vertical velocity of the Bar/Attitube. The prime movers tended to show a reduction in muscle activity during the TUBE trials; however, pectoralis major initially showed increased activation during the eccentric phase of the TUBE condition. The trunk muscle activations were greatest during the TUBE and smallest during the BAR. In addition, the TUBE showed decreased range of elbow flexion and increased medial-lateral movement of the Attitube itself. The results further support the notion that instability devices may be more beneficial for trunk muscles rather than prime movers. PMID:25932979

  5. Prediction of imagined single-joint movements in a person with high-level tetraplegia.

    PubMed

    Ajiboye, A Bolu; Simeral, John D; Donoghue, John P; Hochberg, Leigh R; Kirsch, Robert F

    2012-10-01

    Cortical neuroprostheses for movement restoration require developing models for relating neural activity to desired movement. Previous studies have focused on correlating single-unit activities (SUA) in primary motor cortex to volitional arm movements in able-bodied primates. The extent of the cortical information relevant to arm movements remaining in severely paralyzed individuals is largely unknown. We record intracortical signals using a microelectrode array chronically implanted in the precentral gyrus of a person with tetraplegia, and estimate positions of imagined single-joint arm movements. Using visually guided motor imagery, the participant imagined performing eight distinct single-joint arm movements, while SUA, multispike trains (MSP), multiunit activity, and local field potential time (LFPrms), and frequency signals (LFPstft) were recorded. Using linear system identification, imagined joint trajectories were estimated with 20-60% variance explained, with wrist flexion/extension predicted the best and pronation/supination the poorest. Statistically, decoding of MSP and LFPstft yielded estimates that equaled those of SUA. Including multiple signal types in a decoder increased prediction accuracy in all cases. We conclude that signals recorded from a single restricted region of the precentral gyrus in this person with tetraplegia contained useful information regarding the intended movements of upper extremity joints. PMID:22851229

  6. Arm in Arm

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Backdropped against the blue and white Earth, Mission Specialist (MS) and Payload Commander (PLC) G. David Low and (MS) Peter J.K. Wisoff, wearing Extravehicular Mobility Units (EMUs), simulate handling of large components in space. Above Endeavour's Payload Bay (PLB), Low, anchored by a Portable Foot Restraint (PFR) Manipulator Foot Restraint (MFR) on the Remote Manipulator System (RMS) end effector, maneuvers Wisoff, representing the mass of a large space component. This particular task was rehearsed with eyes toward the servicing of the Hubble Space Telescope (HST) or the assembly and maintenance of Space Station. This Extravehicular Activity (EVA), Detailed Test Objective (DTO) was conducted both with and without intentional disturbances from Endeavour's thrusters and movements of the RMS. The SPACEHAB-01 Commercial Middeck Augmentation Module (CMAM)) is visible in the foreground with the Superfluid Helium On Orbit Transfer (SHOOT) payload liquid helium dewar assembly and the European Retrievable Carrier (EURECA) only partially visible in the aft PLB shadows. The vertical stabilizer and Orbital Maneuvering System (OMS) pods are silhouetted against the Earth's surface.

  7. [Medical support of the Armed Forces of the Russian Federation: results of activity and tasks for 2016].

    PubMed

    Fisun, A Ya

    2016-01-01

    The author gives an analysis of activity of the medical service of the Armed Forces in 2015 concerning development of normative legal basis for the military health care, improvement of the level of operational and mobilization readiness of subunits of army group, and military-medical institutions, improvement of effectiveness of treatment and evacuation measures, health resort treatment, medical stuff training optimization, sanitary-and-epidemiologic support, material and technical support improvement, adoption of advanced scientific achievements focusing on medical care delivery to army group, active development and increase in medical information systems, telehealth. system. The author gives data characterizing state and level of development of medical service of the Armed Forces and its dynamics. Main tasks and parameters of development of the service in 2016 and up to 2020 are formulated. PMID:27120950

  8. Effect of arm swing on single-step balance recovery.

    PubMed

    Cheng, Kuangyou B; Huang, Yi-Chang; Kuo, Shih-Yu

    2014-12-01

    Balance recovery techniques are useful not only in preventing falls but also in many sports activities. The step strategy plays an important role especially under intense perturbations. However, relatively little is known about the effect of arm swing on stepping balance recovery although considerable arm motions have been observed. The purpose of this study was to examine how the arms influence kinematic and kinetic characteristics in single-step balance recovery. Twelve young male adults were released from three forward-lean angles and asked to regain balance by taking a single step under arm swing (AS) and arm constrained (AC) conditions. It was found that unconstrained arms had initial forward motion and later upward motion causing increased moment of inertia of the body, which decreased falling angular velocity and allowed more time for stepping. The lengthened total balance time included weight transfer and stepping time, although duration increase in the latter was significant only at the largest lean angle. In contrast, step length, step velocity, and vertical ground reaction forces on the stepping foot were unaffected by arm swing. Future studies are required to investigate optimal movement strategies for the arms to coordinate with other body segments in balance recovery and injury reduction. PMID:25457416

  9. Voluntary motor commands reveal awareness and control of involuntary movement.

    PubMed

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

    2016-10-01

    The capacity to inhibit actions is central to voluntary motor control. However, the control mechanisms and subjective experience involved in voluntarily stopping an involuntary movement remain poorly understood. Here we examined, in humans, the voluntary inhibition of the Kohnstamm phenomenon, in which sustained voluntary contraction of shoulder abductors is followed by involuntary arm raising. Participants were instructed to stop the involuntary movement, hold the arm in a constant position, and 'release' the inhibition after ∼2s. Participants achieved this by modulating agonist muscle activity, rather than by antagonist contraction. Specifically, agonist muscle activity plateaued during this voluntary inhibition, and resumed its previous increase thereafter. There was no discernible antagonist activation. Thus, some central signal appeared to temporarily counter the involuntary motor drive, without directly affecting the Kohnstamm generator itself. We hypothesise a form of "negative motor command" to account for this novel finding. We next tested the specificity of the negative motor command, by inducing bilateral Kohnstamm movements, and instructing voluntary inhibition for one arm only. The results suggested negative motor commands responsible for inhibition are initially broad, affecting both arms, and then become focused. Finally, a psychophysical investigation found that the perceived force of the aftercontraction was significantly overestimated, relative to voluntary contractions with similar EMG levels. This finding is consistent with the hypothesis that the Kohnstamm generator does not provide an efference copy signal. Our results shed new light on this interesting class of involuntary movement, and provide new information about voluntary inhibition of action. PMID:27399155

  10. Composite body movements modulate numerical cognition: evidence from the motion-numerical compatibility effect.

    PubMed

    Cheng, Xiaorong; Ge, Hui; Andoni, Deljfina; Ding, Xianfeng; Fan, Zhao

    2015-01-01

    A recent hierarchical model of numerical processing, initiated by Fischer and Brugger (2011) and Fischer (2012), suggested that situated factors, such as different body postures and body movements, can influence the magnitude representation and bias numerical processing. Indeed, Loetscher et al. (2008) found that participants' behavior in a random number generation task was biased by head rotations. More small numbers were reported after leftward than rightward head turns, i.e., a motion-numerical compatibility effect. Here, by carrying out two experiments, we explored whether similar motion-numerical compatibility effects exist for movements of other important body components, e.g., arms, and for composite body movements as well, which are basis for complex human activities in many ecologically meaningful situations. In Experiment 1, a motion-numerical compatibility effect was observed for lateral rotations of two body components, i.e., the head and arms. Relatively large numbers were reported after making rightward compared to leftward movements for both lateral head and arm turns. The motion-numerical compatibility effect was observed again in Experiment 2 when participants were asked to perform composite body movements of congruent movement directions, e.g., simultaneous head left turns and arm left turns. However, it disappeared when the movement directions were incongruent, e.g., simultaneous head left turns and arm right turns. Taken together, our results extended Loetscher et al.'s (2008) finding by demonstrating that their effect is effector-general and exists for arm movements. Moreover, our study reveals for the first time that the impact of spatial information on numerical processing induced by each of the two sensorimotor-based situated factors, e.g., a lateral head turn and a lateral arm turn, can cancel each other out. PMID:26594188

  11. Composite body movements modulate numerical cognition: evidence from the motion-numerical compatibility effect

    PubMed Central

    Cheng, Xiaorong; Ge, Hui; Andoni, Deljfina; Ding, Xianfeng; Fan, Zhao

    2015-01-01

    A recent hierarchical model of numerical processing, initiated by Fischer and Brugger (2011) and Fischer (2012), suggested that situated factors, such as different body postures and body movements, can influence the magnitude representation and bias numerical processing. Indeed, Loetscher et al. (2008) found that participants’ behavior in a random number generation task was biased by head rotations. More small numbers were reported after leftward than rightward head turns, i.e., a motion-numerical compatibility effect. Here, by carrying out two experiments, we explored whether similar motion-numerical compatibility effects exist for movements of other important body components, e.g., arms, and for composite body movements as well, which are basis for complex human activities in many ecologically meaningful situations. In Experiment 1, a motion-numerical compatibility effect was observed for lateral rotations of two body components, i.e., the head and arms. Relatively large numbers were reported after making rightward compared to leftward movements for both lateral head and arm turns. The motion-numerical compatibility effect was observed again in Experiment 2 when participants were asked to perform composite body movements of congruent movement directions, e.g., simultaneous head left turns and arm left turns. However, it disappeared when the movement directions were incongruent, e.g., simultaneous head left turns and arm right turns. Taken together, our results extended Loetscher et al.’s (2008) finding by demonstrating that their effect is effector-general and exists for arm movements. Moreover, our study reveals for the first time that the impact of spatial information on numerical processing induced by each of the two sensorimotor-based situated factors, e.g., a lateral head turn and a lateral arm turn, can cancel each other out. PMID:26594188

  12. Activity in descending dopaminergic neurons represents but is not required for leg movements in the fruit fly Drosophila

    PubMed Central

    Tschida, Katherine; Bhandawat, Vikas

    2015-01-01

    Modulatory descending neurons (DNs) that link the brain to body motor circuits, including dopaminergic DNs (DA-DNs), are thought to contribute to the flexible control of behavior. Dopamine elicits locomotor-like outputs and influences neuronal excitability in isolated body motor circuits over tens of seconds to minutes, but it remains unknown how and over what time scale DA-DN activity relates to movement in behaving animals. To address this question, we identified DA-DNs in the Drosophila brain and developed an electrophysiological preparation to record and manipulate the activity of these cells during behavior. We find that DA-DN spike rates are rapidly modulated during a subset of leg movements and scale with the total speed of ongoing leg movements, whether occurring spontaneously or in response to stimuli. However, activating DA-DNs does not elicit leg movements in intact flies, nor do acute bidirectional manipulations of DA-DN activity affect the probability or speed of leg movements over a time scale of seconds to minutes. Our findings indicate that in the context of intact descending control, changes in DA-DN activity are not sufficient to influence ongoing leg movements and open the door to studies investigating how these cells interact with other descending and local neuromodulatory inputs to influence body motor output. PMID:25742959

  13. Electrolocation of objects in fluids by means of active sensor movements based on discrete EEVs.

    PubMed

    Wolf-Homeyer, Sabine; Engelmann, Jacob; Schneider, Axel

    2016-01-01

    Weakly electric fish use self-generated electric fields for communication and for active electrolocation. The sensor part of the biological system consists of a vast amount of electroreceptors which are distributed across the skin of the electric fish. Fish utilise changes of their position and body geometry to aid in the extraction of sensory information. Inspired by the biological model, this study looks for a fixed, minimal scanning strategy compiled of active receptor-system movements that allows unique identification of the positions of objects in the vicinity. The localisation method is based on the superposition of numerical extracted contour-rings of rotated and/or linearly shifted EEVs (Solberg et al 2008 Int. J. Rob. Res. 27 529-48), simulated by means of FEM. For the evaluation of a movement sequence, matrices of unique intersection points and respective contrast functions are introduced. The resultant optimal scanning strategy consists of a combination of a linear shift and a rotation of the original EEV. PMID:27530278

  14. Reduced motor cortex activity during movement preparation following a period of motor skill practice.

    PubMed

    Wright, David J; Holmes, Paul; Di Russo, Francesco; Loporto, Michela; Smith, Dave

    2012-01-01

    Experts in a skill produce movement-related cortical potentials (MRCPs) of smaller amplitude and later onset than novices. This may indicate that, following long-term training, experts require less effort to plan motor skill performance. However, no longitudinal evidence exists to support this claim. To address this, EEG was used to study the effect of motor skill training on cortical activity related to motor planning. Ten non-musicians took part in a 5-week training study learning to play guitar. At week 1, the MRCP was recorded from motor areas whilst participants played the G Major scale. Following a period of practice of the scale, the MRCP was recorded again at week 5. Results showed that the amplitude of the later pre-movement components were smaller at week 5 compared to week 1. This may indicate that, following training, less activity at motor cortex sites is involved in motor skill preparation. This supports claims for a more efficient motor preparation following motor skill training. PMID:23251647

  15. 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.

  16. Transfer of learning between the arms during bimanual reaching.

    PubMed

    Harley, Linda R; Prilutsky, Boris I

    2012-01-01

    This study examined how movement of one arm affects the rate of motor adaptation of the other arm during bimanual reaching in a viscous force-field. Forty healthy adult subjects performed four reaching tasks: (1) by dominant arm, (2) by nondominant arm, (3) by both arms with only dominant arm experiencing force-field and (4) by both arms with only nondominant arm experiencing the force-field. For dominant arm rate of motor adaptation was greater during the bimanual task than the unimanual task. For nondominant arm reaching errors were higher during the bimanual than unimanual task. These results suggest that during bimanual reaching, transfer of learning between arms occur in both directions and movement information transferred depends on arm dominance. PMID:23367487

  17. Multicomponent control strategy underlying production of maximal hand velocity during horizontal arm swing.

    PubMed

    Kim, Young-Kwan; Hinrichs, Richard N; Dounskaia, Natalia

    2009-11-01

    Movement control responsible for generation of maximal hand velocity was studied on the example of horizontal arm swing that is a component of various sports activities. The movement was performed with the nondominant arm in similarity with the baseball bat swing. The task was to generate maximum hand velocity at a target. The movement included trunk long-axis rotation and horizontal shoulder and elbow extension. Kinematics and torque analyses were performed to study the organization of fastest movements and to compare trials representing the best and worst performance in each subject. Results revealed complex control strategy, with the trunk, shoulder, and elbow playing unique roles in generation of maximal hand velocity. The trunk provided a crucial contribution, directly, rotating the entire arm, and indirectly, exerting interaction torque that caused swift elbow extension. The major role of the shoulder was to transfer the mechanical effect of trunk motion to the elbow. However, the shoulder became the primary motion generator when the trunk reached its limits of rotation, revealing sequential organization of control. The role of the elbow was to maximally comply with passive influence of proximal joints. The findings are discussed in light of the leading joint hypothesis that offers a straightforward interpretation of control of horizontal arm swing as well as practically efficient recommendations for increases in movement speed. The revealed role of intersegmental dynamics in production of high movement speed suggests that movement slowness characteristic for some motor disorders may be partially a compensatory strategy that facilitates regulation of interaction torque. PMID:19759324

  18. Multicomponent Control Strategy Underlying Production of Maximal Hand Velocity During Horizontal Arm Swing

    PubMed Central

    Kim, Young-Kwan; Hinrichs, Richard N.

    2009-01-01

    Movement control responsible for generation of maximal hand velocity was studied on the example of horizontal arm swing that is a component of various sports activities. The movement was performed with the nondominant arm in similarity with the baseball bat swing. The task was to generate maximum hand velocity at a target. The movement included trunk long-axis rotation and horizontal shoulder and elbow extension. Kinematics and torque analyses were performed to study the organization of fastest movements and to compare trials representing the best and worst performance in each subject. Results revealed complex control strategy, with the trunk, shoulder, and elbow playing unique roles in generation of maximal hand velocity. The trunk provided a crucial contribution, directly, rotating the entire arm, and indirectly, exerting interaction torque that caused swift elbow extension. The major role of the shoulder was to transfer the mechanical effect of trunk motion to the elbow. However, the shoulder became the primary motion generator when the trunk reached its limits of rotation, revealing sequential organization of control. The role of the elbow was to maximally comply with passive influence of proximal joints. The findings are discussed in light of the leading joint hypothesis that offers a straightforward interpretation of control of horizontal arm swing as well as practically efficient recommendations for increases in movement speed. The revealed role of intersegmental dynamics in production of high movement speed suggests that movement slowness characteristic for some motor disorders may be partially a compensatory strategy that facilitates regulation of interaction torque. PMID:19759324

  19. Octopus-inspired multi-arm robotic swimming.

    PubMed

    Sfakiotakis, M; Kazakidi, A; Tsakiris, D P

    2015-06-01

    The outstanding locomotor and manipulation characteristics of the octopus have recently inspired the development, by our group, of multi-functional robotic swimmers, featuring both manipulation and locomotion capabilities, which could be of significant engineering interest in underwater applications. During its little-studied arm-swimming behavior, as opposed to the better known jetting via the siphon, the animal appears to generate considerable propulsive thrust and rapid acceleration, predominantly employing movements of its arms. In this work, we capture the fundamental characteristics of the corresponding complex pattern of arm motion by a sculling profile, involving a fast power stroke and a slow recovery stroke. We investigate the propulsive capabilities of a multi-arm robotic system under various swimming gaits, namely patterns of arm coordination, which achieve the generation of forward, as well as backward, propulsion and turning. A lumped-element model of the robotic swimmer, which considers arm compliance and the interaction with the aquatic environment, was used to study the characteristics of these gaits, the effect of various kinematic parameters on propulsion, and the generation of complex trajectories. This investigation focuses on relatively high-stiffness arms. Experiments employing a compliant-body robotic prototype swimmer with eight compliant arms, all made of polyurethane, inside a water tank, successfully demonstrated this novel mode of underwater propulsion. Speeds of up to 0.26 body lengths per second (approximately 100 mm s(-1)), and propulsive forces of up to 3.5 N were achieved, with a non-dimensional cost of transport of 1.42 with all eight arms and of 0.9 with only two active arms. The experiments confirmed the computational results and verified the multi-arm maneuverability and simultaneous object grasping capability of such systems. PMID:25970151

  20. Preladenant, a selective A(2A) receptor antagonist, is active in primate models of movement disorders.

    PubMed

    Hodgson, Robert A; Bedard, Paul J; Varty, Geoffrey B; Kazdoba, Tatiana M; Di Paolo, Therese; Grzelak, Michael E; Pond, Annamarie J; Hadjtahar, Abdallah; Belanger, Nancy; Gregoire, Laurent; Dare, Aurelie; Neustadt, Bernard R; Stamford, Andrew W; Hunter, John C

    2010-10-01

    Parkinson's Disease (PD) and Extrapyramidal Syndrome (EPS) are movement disorders that result from degeneration of the dopaminergic input to the striatum and chronic inhibition of striatal dopamine D(2) receptors by antipsychotics, respectively. Adenosine A(2A) receptors are selectively localized in the basal ganglia, primarily in the striatopallidal ("indirect") pathway, where they appear to operate in concert with D(2) receptors and have been suggested to drive striatopallidal output balance. In cases of dopaminergic hypofunction, A(2A) receptor activation contributes to the overdrive of the indirect pathway. A(2A) receptor antagonists, therefore, have the potential to restore this inhibitor imbalance. Consequently, A(2A) receptor antagonists have therapeutic potential in diseases of dopaminergic hypofunction such as PD and EPS. Targeting the A(2A) receptor may also be a way to avoid the issues associated with direct dopamine agonists. Recently, preladenant was identified as a potent and highly selective A(2A) receptor antagonist, and has produced a significant improvement in motor function in rodent models of PD. Here we investigate the effects of preladenant in two primate movement disorder models. In MPTP-treated cynomolgus monkeys, preladenant (1 or 3 mg/kg; PO) improved motor ability and did not evoke any dopaminergic-mediated dyskinetic or motor complications. In Cebus apella monkeys with a history of chronic haloperidol treatment, preladenant (0.3-3.0 mg/kg; PO) delayed the onset of EPS symptoms evoked by an acute haloperidol challenge. Collectively, these data support the use of preladenant for the treatment of PD and antipsychotic-induced movement disorders. PMID:20655910

  1. 3D visualization of movements can amplify motor cortex activation during subsequent motor imagery.

    PubMed

    Sollfrank, Teresa; Hart, Daniel; Goodsell, Rachel; Foster, Jonathan; Tan, Tele

    2015-01-01

    A repetitive movement practice by motor imagery (MI) can influence motor cortical excitability in the electroencephalogram (EEG). This study investigated if a realistic visualization in 3D of upper and lower limb movements can amplify motor related potentials during subsequent MI. We hypothesized that a richer sensory visualization might be more effective during instrumental conditioning, resulting in a more pronounced event related desynchronization (ERD) of the upper alpha band (10-12 Hz) over the sensorimotor cortices thereby potentially improving MI based brain-computer interface (BCI) protocols for motor rehabilitation. The results show a strong increase of the characteristic patterns of ERD of the upper alpha band components for left and right limb MI present over the sensorimotor areas in both visualization conditions. Overall, significant differences were observed as a function of visualization modality (VM; 2D vs. 3D). The largest upper alpha band power decrease was obtained during MI after a 3-dimensional visualization. In total in 12 out of 20 tasks the end-user of the 3D visualization group showed an enhanced upper alpha ERD relative to 2D VM group, with statistical significance in nine tasks.With a realistic visualization of the limb movements, we tried to increase motor cortex activation during subsequent MI. The feedback and the feedback environment should be inherently motivating and relevant for the learner and should have an appeal of novelty, real-world relevance or aesthetic value (Ryan and Deci, 2000; Merrill, 2007). Realistic visual feedback, consistent with the participant's MI, might be helpful for accomplishing successful MI and the use of such feedback may assist in making BCI a more natural interface for MI based BCI rehabilitation. PMID:26347642

  2. 3D visualization of movements can amplify motor cortex activation during subsequent motor imagery

    PubMed Central

    Sollfrank, Teresa; Hart, Daniel; Goodsell, Rachel; Foster, Jonathan; Tan, Tele

    2015-01-01

    A repetitive movement practice by motor imagery (MI) can influence motor cortical excitability in the electroencephalogram (EEG). This study investigated if a realistic visualization in 3D of upper and lower limb movements can amplify motor related potentials during subsequent MI. We hypothesized that a richer sensory visualization might be more effective during instrumental conditioning, resulting in a more pronounced event related desynchronization (ERD) of the upper alpha band (10–12 Hz) over the sensorimotor cortices thereby potentially improving MI based brain-computer interface (BCI) protocols for motor rehabilitation. The results show a strong increase of the characteristic patterns of ERD of the upper alpha band components for left and right limb MI present over the sensorimotor areas in both visualization conditions. Overall, significant differences were observed as a function of visualization modality (VM; 2D vs. 3D). The largest upper alpha band power decrease was obtained during MI after a 3-dimensional visualization. In total in 12 out of 20 tasks the end-user of the 3D visualization group showed an enhanced upper alpha ERD relative to 2D VM group, with statistical significance in nine tasks.With a realistic visualization of the limb movements, we tried to increase motor cortex activation during subsequent MI. The feedback and the feedback environment should be inherently motivating and relevant for the learner and should have an appeal of novelty, real-world relevance or aesthetic value (Ryan and Deci, 2000; Merrill, 2007). Realistic visual feedback, consistent with the participant’s MI, might be helpful for accomplishing successful MI and the use of such feedback may assist in making BCI a more natural interface for MI based BCI rehabilitation. PMID:26347642

  3. Activated STAT1 Transcription Factors Conduct Distinct Saltatory Movements in the Cell Nucleus

    PubMed Central

    Speil, Jasmin; Baumgart, Eugen; Siebrasse, Jan-Peter; Veith, Roman; Vinkemeier, Uwe; Kubitscheck, Ulrich

    2011-01-01

    The activation of STAT transcription factors is a critical determinant of their subcellular distribution and their ability to regulate gene expression. Yet, it is not known how activation affects the behavior of individual STAT molecules in the cytoplasm and nucleus. To investigate this issue, we injected fluorescently labeled STAT1 in living HeLa cells and traced them by single-molecule microscopy. We determined that STAT1 moved stochastically in the cytoplasm and nucleus with very short residence times (<0.03 s) before activation. Upon activation, STAT1 mobility in the cytoplasm decreased ∼2.5-fold, indicating reduced movement of STAT1/importinα/β complexes to the nucleus. In the nucleus, activated STAT1 displayed a distinct saltatory mobility, with residence times of up to 5 s and intermittent diffusive motion. In this manner, activated STAT1 factors can occupy their putative chromatin target sites within ∼2 s. These results provide a better understanding of the timescales on which cellular signaling and regulated gene transcription operate at the single-molecule level. PMID:22261046

  4. Neural activation in cognitive motor processes: comparing motor imagery and observation of gymnastic movements.

    PubMed

    Munzert, Jörn; Zentgraf, Karen; Stark, Rudolf; Vaitl, Dieter

    2008-07-01

    The simulation concept suggested by Jeannerod (Neuroimage 14:S103-S109, 2001) defines the S-states of action observation and mental simulation of action as action-related mental states lacking overt execution. Within this framework, similarities and neural overlap between S-states and overt execution are interpreted as providing the common basis for the motor representations implemented within the motor system. The present brain imaging study compared activation overlap and differential activation during mental simulation (motor imagery) with that while observing gymnastic movements. The fMRI conjunction analysis revealed overlapping activation for both S-states in primary motor cortex, premotor cortex, and the supplementary motor area as well as in the intraparietal sulcus, cerebellar hemispheres, and parts of the basal ganglia. A direct contrast between the motor imagery and observation conditions revealed stronger activation for imagery in the posterior insula and the anterior cingulate gyrus. The hippocampus, the superior parietal lobe, and the cerebellar areas were differentially activated in the observation condition. In general, these data corroborate the concept of action-related S-states because of the high overlap in core motor as well as in motor-related areas. We argue that differential activity between S-states relates to task-specific and modal information processing. PMID:18425505

  5. Movement preparation and execution: differential functional activation patterns after traumatic brain injury.

    PubMed

    Gooijers, Jolien; Beets, Iseult A M; Albouy, Genevieve; Beeckmans, Kurt; Michiels, Karla; Sunaert, Stefan; Swinnen, Stephan P

    2016-09-01

    Years following the insult, patients with traumatic brain injury often experience persistent motor control problems, including bimanual coordination deficits. Previous studies revealed that such deficits are related to brain structural white and grey matter abnormalities. Here, we assessed, for the first time, cerebral functional activation patterns during bimanual movement preparation and performance in patients with traumatic brain injury, using functional magnetic resonance imaging. Eighteen patients with moderate-to-severe traumatic brain injury (10 females; aged 26.3 years, standard deviation = 5.2; age range: 18.4-34.6 years) and 26 healthy young adults (15 females; aged 23.6 years, standard deviation = 3.8; age range: 19.5-33 years) performed a complex bimanual tracking task, divided into a preparation (2 s) and execution (9 s) phase, and executed either in the presence or absence of augmented visual feedback. Performance on the bimanual tracking task, expressed as the average target error, was impaired for patients as compared to controls (P < 0.001) and for trials in the absence as compared to the presence of augmented visual feedback (P < 0.001). At the cerebral level, movement preparation was characterized by reduced neural activation in the patient group relative to the control group in frontal (bilateral superior frontal gyrus, right dorsolateral prefrontal cortex), parietal (left inferior parietal lobe) and occipital (right striate and extrastriate visual cortex) areas (P's < 0.05). During the execution phase, however, the opposite pattern emerged, i.e. traumatic brain injury patients showed enhanced activations compared with controls in frontal (left dorsolateral prefrontal cortex, left lateral anterior prefrontal cortex, and left orbitofrontal cortex), parietal (bilateral inferior parietal lobe, bilateral superior parietal lobe, right precuneus, right primary somatosensory cortex), occipital (right striate and extrastriate visual cortices), and

  6. The effects of task-oriented versus repetitive bilateral arm training on upper limb function and activities of daily living in stroke patients

    PubMed Central

    Song, Gui Bin

    2015-01-01

    [Purpose] The purpose of this study was to investigate the effects of task-oriented bilateral arm training and repetitive bilateral arm training on upper limb function and activities of daily living in stroke patients. [Subjects] Forty patients with hemiplegia resulting from stroke were divided into a task orientied bilateral arm training group (n=20) and a repetitive bilateral arm training group (n=20). [Methods] The task-oriented group underwent bilateral arm training with 5 functional tasks, and the repetitive group underwent bilateral arm training with rhythmin auditory cueing for 30 minutes/day, 5 times/week, for 12 weeks. [Results] The upper limb function and the ability to perform activities of daily living improved significantly in both groups. Although there were significant differences between the groups, the task-oriented group showed greater improvement in upper limb function and activities of daily living. [Conclusion] We recommend bilateral arm training as well as adding functional task training as a clinical intervention to improve upper limb function activities of daily living in patients with hemiplegia. PMID:26157217

  7. Inspiratory muscle fatigue affects latissimus dorsi but not pectoralis major activity during arms only front crawl sprinting.

    PubMed

    Lomax, Mitch; Tasker, Louise; Bostanci, Ozgur

    2014-08-01

    The purpose of this study was to determine whether inspiratory muscle fatigue (IMF) affects the muscle activity of the latissimus dorsi and pectoralis major during maximal arms only front crawl swimming. Eight collegiate swimmers were recruited to perform 2 maximal 20-second arms only front crawl sprints in a swimming flume. Both sprints were performed on the same day, and IMF was induced 30 minutes after the first (control) sprint. Maximal inspiratory and expiratory mouth pressures (PImax and PEmax, respectively) were measured before and after each sprint. The median frequency (MDF) of the electromyographic signal burst was recorded from the latissimus dorsi and pectoralis major during each 20-second sprint along with stroke rate and breathing frequency. Median frequency was assessed in absolute units (Hz) and then referenced to the start of the control sprint for normalization. After IMF inducement, stroke rate increased from 56 ± 4 to 59 ± 5 cycles per minute, and latissimus dorsi MDF fell from 67 ± 11 Hz at the start of the sprint to 61 ± 9 Hz at the end. No change was observed in the MDF of the latissimus dorsi during the control sprint. Conversely, the MDF of the pectoralis major shifted to lower frequencies during both sprints but was unaffected by IMF. As the latter induced fatigue in the latissimus dorsi, which was not otherwise apparent during maximal arms only control sprinting, the presence of IMF affects the activity of the latissimus dorsi during front crawl sprinting. PMID:24402450

  8. Development of Biological Movement Recognition by Interaction between Active Basis Model and Fuzzy Optical Flow Division

    PubMed Central

    Loo, Chu Kiong

    2014-01-01

    Following the study on computational neuroscience through functional magnetic resonance imaging claimed that human action recognition in the brain of mammalian pursues two separated streams, that is, dorsal and ventral streams. It follows up by two pathways in the bioinspired model, which are specialized for motion and form information analysis (Giese and Poggio 2003). Active basis model is used to form information which is different from orientations and scales of Gabor wavelets to form a dictionary regarding object recognition (human). Also biologically movement optic-flow patterns utilized. As motion information guides share sketch algorithm in form pathway for adjustment plus it helps to prevent wrong recognition. A synergetic neural network is utilized to generate prototype templates, representing general characteristic form of every class. Having predefined templates, classifying performs based on multitemplate matching. As every human action has one action prototype, there are some overlapping and consistency among these templates. Using fuzzy optical flow division scoring can prevent motivation for misrecognition. We successfully apply proposed model on the human action video obtained from KTH human action database. Proposed approach follows the interaction between dorsal and ventral processing streams in the original model of the biological movement recognition. The attained results indicate promising outcome and improvement in robustness using proposed approach. PMID:24883361

  9. Development of biological movement recognition by interaction between active basis model and fuzzy optical flow division.

    PubMed

    Yousefi, Bardia; Loo, Chu Kiong

    2014-01-01

    Following the study on computational neuroscience through functional magnetic resonance imaging claimed that human action recognition in the brain of mammalian pursues two separated streams, that is, dorsal and ventral streams. It follows up by two pathways in the bioinspired model, which are specialized for motion and form information analysis (Giese and Poggio 2003). Active basis model is used to form information which is different from orientations and scales of Gabor wavelets to form a dictionary regarding object recognition (human). Also biologically movement optic-flow patterns utilized. As motion information guides share sketch algorithm in form pathway for adjustment plus it helps to prevent wrong recognition. A synergetic neural network is utilized to generate prototype templates, representing general characteristic form of every class. Having predefined templates, classifying performs based on multitemplate matching. As every human action has one action prototype, there are some overlapping and consistency among these templates. Using fuzzy optical flow division scoring can prevent motivation for misrecognition. We successfully apply proposed model on the human action video obtained from KTH human action database. Proposed approach follows the interaction between dorsal and ventral processing streams in the original model of the biological movement recognition. The attained results indicate promising outcome and improvement in robustness using proposed approach. PMID:24883361

  10. Movements, Countermovements and Policy Adoption: The Case of Right-to-Work Activism

    ERIC Educational Resources Information Center

    Dixon, Marc

    2008-01-01

    Research on social movements and public policy has expanded tremendously in recent years, yet little of this work considers the role of movement opponents in the political process or how the movement-countermovement dynamic is influential in contests over policy. This historical study begins to fill this void by analyzing the contestation between…

  11. Adaptive tuning functions arise from visual observation of past movement

    PubMed Central

    Howard, Ian S.; Franklin, David W.

    2016-01-01

    Visual observation of movement plays a key role in action. For example, tennis players have little time to react to the ball, but still need to prepare the appropriate stroke. Therefore, it might be useful to use visual information about the ball trajectory to recall a specific motor memory. Past visual observation of movement (as well as passive and active arm movement) affects the learning and recall of motor memories. Moreover, when passive or active, these past contextual movements exhibit generalization (or tuning) across movement directions. Here we extend this work, examining whether visual motion also exhibits similar generalization across movement directions and whether such generalization functions can explain patterns of interference. Both the adaptation movement and contextual movement exhibited generalization beyond the training direction, with the visual contextual motion exhibiting much broader tuning. A second experiment demonstrated that this pattern was consistent with the results of an interference experiment where opposing force fields were associated with two separate visual movements. Overall, our study shows that visual contextual motion exhibits much broader (and shallower) tuning functions than previously seen for either passive or active movements, demonstrating that the tuning characteristics of past motion are highly dependent on their sensory modality. PMID:27341163

  12. Adaptive tuning functions arise from visual observation of past movement.

    PubMed

    Howard, Ian S; Franklin, David W

    2016-01-01

    Visual observation of movement plays a key role in action. For example, tennis players have little time to react to the ball, but still need to prepare the appropriate stroke. Therefore, it might be useful to use visual information about the ball trajectory to recall a specific motor memory. Past visual observation of movement (as well as passive and active arm movement) affects the learning and recall of motor memories. Moreover, when passive or active, these past contextual movements exhibit generalization (or tuning) across movement directions. Here we extend this work, examining whether visual motion also exhibits similar generalization across movement directions and whether such generalization functions can explain patterns of interference. Both the adaptation movement and contextual movement exhibited generalization beyond the training direction, with the visual contextual motion exhibiting much broader tuning. A second experiment demonstrated that this pattern was consistent with the results of an interference experiment where opposing force fields were associated with two separate visual movements. Overall, our study shows that visual contextual motion exhibits much broader (and shallower) tuning functions than previously seen for either passive or active movements, demonstrating that the tuning characteristics of past motion are highly dependent on their sensory modality. PMID:27341163

  13. Executive control modulates cross-language lexical activation during L2 reading: evidence from eye movements.

    PubMed

    Pivneva, Irina; Mercier, Julie; Titone, Debra

    2014-05-01

    Models of bilingual reading such as Bilingual Interactive Activation Plus (Dijkstra & van Heuven, 2002) do not predict a central role for domain-general executive control during bilingual reading, in contrast with bilingual models from other domains, such as production (e.g., the Inhibitory Control Model; Green, 1998). We thus investigated whether individual differences among bilinguals in domain-general executive control modulate cross-language activation during L2 sentence reading, over and above other factors such as L2 proficiency. Fifty French-English bilinguals read L2-English sentences while their eye movements were recorded, and they subsequently completed a battery of executive control and L2 proficiency tasks. High- and low-constraint sentences contained interlingual homographs (chat = "casual conversation" in English, "a cat" in French), cognates (piano in English and French), or L2-specific control words. The results showed that greater executive control among bilinguals but not L2 proficiency reduced cross-language activation in terms of interlingual homograph interference. In contrast, increased L2 proficiency but not executive control reduced cross-language activation in terms of cognate facilitation. These results suggest that models of bilingual reading must incorporate mechanisms by which domain-general executive control can alter the earliest stages of bilingual lexical activation. PMID:24446754

  14. fNIRS: An Emergent Method to Document Functional Cortical Activity during Infant Movements

    PubMed Central

    Nishiyori, Ryota

    2016-01-01

    The neural basis underlying the emergence of goal-directed actions in infants has been severely understudied, with minimal empirical evidence for hypotheses proposed. This was largely due to the technological constraints of traditional neuroimaging techniques. Recently, functional near-infrared spectroscopy (fNIRS) technology has emerged as a tool developmental scientists are finding useful to examine cortical activity, particularly in young children and infants due to its greater tolerance to movements than other neuroimaging techniques. fNIRS provides an opportunity to finally begin to examine the neural underpinnings as infants develop goal-directed actions. In this methodological paper, I will outline the utility, challenges, and outcomes of using fNIRS to measure the changes in cortical activity as infants reach for an object. I will describe the advantages and limitations of the technology, the setup I used to study primary motor cortex activity during infant reaching, and example steps in the analyses processes. I will present exemplar data to illustrate the feasibility of this technique to quantify changes in hemodynamic activity as infants move. The viability of this research method opens the door to expanding studies of the development of neural activity related to goal-directed actions in infants. I encourage others to share details of techniques used, as well, including analyticals, to help this neuroimaging technology grow as others, such as EEG and fMRI have. PMID:27148141

  15. fNIRS: An Emergent Method to Document Functional Cortical Activity during Infant Movements.

    PubMed

    Nishiyori, Ryota

    2016-01-01

    The neural basis underlying the emergence of goal-directed actions in infants has been severely understudied, with minimal empirical evidence for hypotheses proposed. This was largely due to the technological constraints of traditional neuroimaging techniques. Recently, functional near-infrared spectroscopy (fNIRS) technology has emerged as a tool developmental scientists are finding useful to examine cortical activity, particularly in young children and infants due to its greater tolerance to movements than other neuroimaging techniques. fNIRS provides an opportunity to finally begin to examine the neural underpinnings as infants develop goal-directed actions. In this methodological paper, I will outline the utility, challenges, and outcomes of using fNIRS to measure the changes in cortical activity as infants reach for an object. I will describe the advantages and limitations of the technology, the setup I used to study primary motor cortex activity during infant reaching, and example steps in the analyses processes. I will present exemplar data to illustrate the feasibility of this technique to quantify changes in hemodynamic activity as infants move. The viability of this research method opens the door to expanding studies of the development of neural activity related to goal-directed actions in infants. I encourage others to share details of techniques used, as well, including analyticals, to help this neuroimaging technology grow as others, such as EEG and fMRI have. PMID:27148141

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

    PubMed Central

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

    2016-01-01

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

  17. Designing and testing lightweight shoulder prostheses with hybrid actuators for movements involved in typical activities of daily living and impact absorption

    PubMed Central

    Sekine, Masashi; Kita, Kahori; Yu, Wenwei

    2015-01-01

    Unlike forearm amputees, transhumeral amputees have residual stumps that are too small to provide a sufficient range of operation for their prosthetic parts to perform usual activities of daily living. Furthermore, it is difficult for small residual stumps to provide sufficient impact absorption for safe manipulation in daily living, as intact arms do. Therefore, substitution of upper limb function in transhumeral amputees requires a sufficient range of motion and sufficient viscoelasticity for shoulder prostheses under critical weight and dimension constraints. We propose the use of two different types of actuators, ie, pneumatic elastic actuators (PEAs) and servo motors. PEAs offer high power-to-weight performance and have intrinsic viscoelasticity in comparison with motors or standard industrial pneumatic cylinder actuators. However, the usefulness of PEAs in large working spaces is limited because of their short strokes. Servo motors, in contrast, can be used to achieve large ranges of motion. In this study, the relationship between the force and stroke of PEAs was investigated. The impact absorption of both types of actuators was measured using a single degree-of-freedom prototype to evaluate actuator compliance for safety purposes. Based on the fundamental properties of the actuators identified, a four degree-of-freedom robotic arm is proposed for prosthetic use. The configuration of the actuators and functional parts was designed to achieve a specified range of motion and torque calculated from the results of a simulation of typical movements performed in usual activities of daily living. Our experimental results showed that the requirements for the shoulder prostheses could be satisfied. PMID:26185472

  18. [Prospective planning of activity of the Medical service of the Armed Forces of the Russian Federation for 2016-2020].

    PubMed

    Fisun, A Ya; Kalachev, O V; Redkin, E E; Bershev, M A; Murzo, A V

    2016-04-01

    The article reflects the characteristics of the Plan of activities of the Ministry of Defence of the Russian Federation for 2016-2020--an important long-term planning document of the Armed Forces. It stressed the need for synchronization of activities for chain of command and deadline. Presented structure of the Medical Service Plan Military District operations (fleet) military medical organization. The attention is focused on the content of its sections. For example, a military hospital layouts presented an action plan and a schedule of events. Reflecting the requirements of the Minister of Defense for the development and adjustment plans, indicators of their performance. PMID:27416714

  19. Fear of Movement and Low Self-Efficacy Are Important Barriers in Physical Activity after Renal Transplantation

    PubMed Central

    Zelle, Dorien M.; Corpeleijn, Eva; Klaassen, Gerald; Schutte, Elise; Navis, Gerjan; Bakker, Stephan J. L.

    2016-01-01

    Background Physical activity (PA) and exercise are commonly used as preventive measures for cardiovascular disease in the general population, and could be effective in the management of post-transplantation cardiovascular risk. PA levels are low after renal transplantation and very few renal transplant recipients (RTR) meet the PA guidelines. Identification of barriers to regular PA is important to identify targets for intervention to improve PA levels after renal transplantation. We investigated fear of movement and physical self-efficacy as barriers to PA in RTR. Methods RTR were investigated between 2001–2003. The Tampa Score of Kinesiophobia–Dutch Version (TSK-11) was used to assess fear of movement. Physical self-efficacy was measured with the LIVAS-scale. PA was assessed using validated questionnaires (Tecumseh Occupational Activity Questionnaire and the Minnesota Leisure Time Physical Activity Questionnaire). Results A total of 487 RTR (age 51±12 years, 55% men) were studied. Median score [interquartile range] on TSK-11 was 22 [17–26]. Low physical self-efficacy (Exp B:0.41[0.31–0.54], p<0.001) and history of myocardial infarction, transient ischemic attack and cerebrovascular accident (Exp B:1.30[1.03–1.63],p = 0.03) were independent determinants for fear of movement. Fear of movement was associated with lower daily PA, occupational, sports and leisure time PA. Mediation-analysis showed that a large part (73%) of the effect of fear of movement on PA was explained by low physical self-efficacy. Conclusions This study was the first to examine fear of movement and self-efficacy in relation to PA in RTR. Fear of movement was associated with a low PA level, and the larger part of this relation was mediated by low physical self-efficacy. Both fear of movement and physical self-efficacy level are important targets for intervention during rehabilitation after renal transplantation. PMID:26844883

  20. Multiple EMG activity and intracortical inhibition and facilitation during a fine finger movement under pressure.

    PubMed

    Tanaka, Yoshifumi; Funase, Kozo; Sekiya, Hiroshi; Sasaki, Joyo; Takemoto, Toru

    2011-01-01

    The 1st purpose of this study was to examine multiple electromyography (EMG) during voluntary hand movements. A secondary purpose was to investigate possible effects of pressure on intracortical inhibition (ICI) and intracortical facilitation (ICF) functions of the motor cortex, using paired-pulse transcranial magnetic stimulation. Twelve participants traced a 15-cm diameter target circle using a small laser pointer attached to the right index finger. After 5 acquisition trials, they performed 3 nonpressure trials followed by 3 pressure trials. The results showed that pressure had effects not only on agonist EMG activity but also on multiple muscles, such as synergist. In addition, a decrease in ICI and an increase in ICF were both observed under pressure for muscles other than the agonist. PMID:21218324

  1. Preparatory EMG activity reveals a rapid adaptation pattern in humans performing landing movements in blindfolded condition.

    PubMed

    Magalhães, Fernando Henrique; Goroso, Daniel Gustavo

    2009-10-01

    The main questions addressed in this work were whether and how adaptation to suppression of visual information occurs in a free-fall paradigm, and the extent to which vision availability influences the control of landing movements. The prelanding modulation of EMG timing and amplitude of four lower-limb muscles was investigated. Participants performed six consecutive drop-landings from four different heights in two experimental conditions: with and without vision. Experimental design precluded participants from estimating the height of the drop. Since cues provided by proprioceptive and vestibular information acquired during the first trials were processed, the nervous system rapidly adapted to the lack of visual information, and hence produced a motor output (i.e., prelanding EMG modulation) similar to that observed when performing the activity with vision available. PMID:20038004

  2. Hierarchical clustering of brain activity during human nonrapid eye movement sleep

    PubMed Central

    Boly, Mélanie; Perlbarg, Vincent; Marrelec, Guillaume; Schabus, Manuel; Laureys, Steven; Doyon, Julien; Pélégrini-Issac, Mélanie; Maquet, Pierre; Benali, Habib

    2012-01-01

    Consciousness is reduced during nonrapid eye movement (NREM) sleep due to changes in brain function that are still poorly understood. Here, we tested the hypothesis that impaired consciousness during NREM sleep is associated with an increased modularity of brain activity. Cerebral connectivity was quantified in resting-state functional magnetic resonance imaging times series acquired in 13 healthy volunteers during wakefulness and NREM sleep. The analysis revealed a modification of the hierarchical organization of large-scale networks into smaller independent modules during NREM sleep, independently from EEG markers of the slow oscillation. Such modifications in brain connectivity, possibly driven by sleep ultraslow oscillations, could hinder the brain's ability to integrate information and account for decreased consciousness during NREM sleep. PMID:22451917

  3. Congenital mirror movements.

    PubMed Central

    Schott, G D; Wyke, M A

    1981-01-01

    In this report are described seven patients assessed clinically and neuropsychologically in whom mirror movements affecting predominantly the hands occurred as a congenital disorder. These mirror movements, representing a specific type of abnormal synkinesia, may arise as a hereditary condition, in the presence of a recognisable underlying neurological abnormality, and sporadically, and the seven patients provide more or less satisfactory examples of each of these three groups. Despite the apparent uniformity of the disorder, the heterogeneity and variability may be marked, examples in some of our patients including the pronounced increase in tone that developed with arm movement, and the capacity for modulation of the associated movement by alteration of neck position and bio-feedback. Various possible mechanisms are considered; these include impaired cerebral inhibition of unwanted movements, and functioning of abnormal motor pathways. Emphasis has been placed on the putative role of the direct, crossed corticomotoneurone pathways and on the unilateral and bilateral cerebral events that precede movement. PMID:7288446

  4. 49 CFR 234.255 - Gate arm and gate mechanism.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Gate arm and gate mechanism. 234.255 Section 234... Maintenance, Inspection, and Testing Inspections and Tests § 234.255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall...

  5. 49 CFR 234.255 - Gate arm and gate mechanism.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Gate arm and gate mechanism. 234.255 Section 234....255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall be observed for proper operation at least once each month....

  6. 49 CFR 234.255 - Gate arm and gate mechanism.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Gate arm and gate mechanism. 234.255 Section 234....255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall be observed for proper operation at least once each month....

  7. 49 CFR 234.255 - Gate arm and gate mechanism.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Gate arm and gate mechanism. 234.255 Section 234... Maintenance, Inspection, and Testing Inspections and Tests § 234.255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall...

  8. 49 CFR 234.255 - Gate arm and gate mechanism.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Gate arm and gate mechanism. 234.255 Section 234....255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall be observed for proper operation at least once each month....

  9. Differences in Movement Mechanics, Electromyographic, and Motor Cortex Activity Between Accurate and Nonaccurate Stepping

    PubMed Central

    Farrell, Bradley J.; Sirota, Mikhail G.; Prilutsky, Boris I.

    2010-01-01

    What are the differences in mechanics, muscle, and motor cortex activity between accurate and nonaccurate movements? We addressed this question in relation to walking. We assessed full-body mechanics (229 variables), activity of 8 limb muscles, and activity of 63 neurons from the motor cortex forelimb representation during well-trained locomotion with different demands on the accuracy of paw placement in cats: during locomotion on a continuous surface and along horizontal ladders with crosspieces of different widths. We found that with increasing accuracy demands, cats assumed a more bent-forward posture (by lowering the center of mass, rotating the neck and head down, and by increasing flexion of the distal joints) and stepped on the support surface with less spatial variability. On the ladder, the wrist flexion moment was lower throughout stance, whereas ankle and knee extension moments were higher and hip moment was lower during early stance compared with unconstrained locomotion. The horizontal velocity time histories of paws were symmetric and smooth and did not differ among the tasks. Most of the other mechanical variables also did not depend on accuracy demands. Selected distal muscles slightly enhanced their activity with increasing accuracy demands. However, in a majority of motor cortex cells, discharge rate means, peaks, and depths of stride-related frequency modulation changed dramatically during accurate stepping as compared with simple walking. In addition, in 30% of neurons periods of stride-related elevation in firing became shorter and in 20–25% of neurons activity or depth of frequency modulation increased, albeit not linearly, with increasing accuracy demands. Considering the relatively small changes in locomotor mechanics and substantial changes in motor cortex activity with increasing accuracy demands, we conclude that during practiced accurate stepping the activity of motor cortex reflects other processes, likely those that involve

  10. Differences in movement mechanics, electromyographic, and motor cortex activity between accurate and nonaccurate stepping.

    PubMed

    Beloozerova, Irina N; Farrell, Bradley J; Sirota, Mikhail G; Prilutsky, Boris I

    2010-04-01

    What are the differences in mechanics, muscle, and motor cortex activity between accurate and nonaccurate movements? We addressed this question in relation to walking. We assessed full-body mechanics (229 variables), activity of 8 limb muscles, and activity of 63 neurons from the motor cortex forelimb representation during well-trained locomotion with different demands on the accuracy of paw placement in cats: during locomotion on a continuous surface and along horizontal ladders with crosspieces of different widths. We found that with increasing accuracy demands, cats assumed a more bent-forward posture (by lowering the center of mass, rotating the neck and head down, and by increasing flexion of the distal joints) and stepped on the support surface with less spatial variability. On the ladder, the wrist flexion moment was lower throughout stance, whereas ankle and knee extension moments were higher and hip moment was lower during early stance compared with unconstrained locomotion. The horizontal velocity time histories of paws were symmetric and smooth and did not differ among the tasks. Most of the other mechanical variables also did not depend on accuracy demands. Selected distal muscles slightly enhanced their activity with increasing accuracy demands. However, in a majority of motor cortex cells, discharge rate means, peaks, and depths of stride-related frequency modulation changed dramatically during accurate stepping as compared with simple walking. In addition, in 30% of neurons periods of stride-related elevation in firing became shorter and in 20-25% of neurons activity or depth of frequency modulation increased, albeit not linearly, with increasing accuracy demands. Considering the relatively small changes in locomotor mechanics and substantial changes in motor cortex activity with increasing accuracy demands, we conclude that during practiced accurate stepping the activity of motor cortex reflects other processes, likely those that involve integration

  11. Scapular and rotator cuff muscle activity during arm elevation: A review of normal function and alterations with shoulder impingement

    PubMed Central

    Phadke, V; Camargo, PR; Ludewig, PM

    2009-01-01

    Objective The purpose of this manuscript is to review current knowledge of how muscle activation and force production contribute to shoulder kinematics in healthy subjects and persons with shoulder impingement. Results The middle and lower serratus anterior muscles produce scapular upward rotation, posterior tilting, and external rotation. Upper trapezius produces clavicular elevation and retraction. The middle trapezius is primarily a medial stabilizer of the scapula. The lower trapezius assists in medial stabilization and upward rotation of the scapula. The pectoralis minor is aligned to resist normal rotations of the scapula during arm elevation. The rotator cuff is critical to stabilization and prevention of excess superior translation of the humeral head, as well as production of glenohumeral external rotation during arm elevation. Alterations in activation amplitude or timing have been identified across various investigations of subjects with shoulder impingement as compared to healthy controls. These include decreased activation of the middle or lower serratus anterior and rotator cuff, delayed activation of middle and lower trapezius, and increased activation of the upper trapezius and middle deltoid in impingement subjects. In addition, subjects with a short resting length of the pectoralis minor exhibit altered scapular kinematic patterns similar to those found in persons with shoulder impingement. Conclusion These normal muscle functional capabilities and alterations in patient populations should be considered when planning exercise approaches for the rehabilitation of these patients. PMID:20411160

  12. Valid and reliable instruments for arm-hand assessment at ICF activity level in persons with hemiplegia: a systematic review

    PubMed Central

    2012-01-01

    Background Loss of arm-hand performance due to a hemiparesis as a result of stroke or cerebral palsy (CP), leads to large problems in daily life of these patients. Assessment of arm-hand performance is important in both clinical practice and research. To gain more insight in e.g. effectiveness of common therapies for different patient populations with similar clinical characteristics, consensus regarding the choice and use of outcome measures is paramount. To guide this choice, an overview of available instruments is necessary. The aim of this systematic review is to identify, evaluate and categorize instruments, reported to be valid and reliable, assessing arm-hand performance at the ICF activity level in patients with stroke or cerebral palsy. Methods A systematic literature search was performed to identify articles containing instruments assessing arm-hand skilled performance in patients with stroke or cerebral palsy. Instruments were identified and divided into the categories capacity, perceived performance and actual performance. A second search was performed to obtain information on their content and psychometrics. Results Regarding capacity, perceived performance and actual performance, 18, 9 and 3 instruments were included respectively. Only 3 of all included instruments were used and tested in both patient populations. The content of the instruments differed widely regarding the ICF levels measured, assessment of the amount of use versus the quality of use, the inclusion of unimanual and/or bimanual tasks and the inclusion of basic and/or extended tasks. Conclusions Although many instruments assess capacity and perceived performance, a dearth exists of instruments assessing actual performance. In addition, instruments appropriate for more than one patient population are sparse. For actual performance, new instruments have to be developed, with specific focus on the usability in different patient populations and the assessment of quality of use as well as

  13. The Relationship between Fundamental Movement Skills and Self-Reported Physical Activity during Finnish Junior High School

    ERIC Educational Resources Information Center

    Jaakkola, Timo; Washington, Tracy

    2013-01-01

    Background: Previous studies have shown that fundamental movement skills (FMS) and physical activity are related. Specifically, earlier studies have demonstrated that the ability to perform a variety of FMS increases the likelihood of children participating in a range of physical activities throughout their lives. To date, however, there have not…

  14. A new way of assessing arm function in activity using kinematic Exposure Variation Analysis and portable inertial sensors--A validity study.

    PubMed

    Ertzgaard, Per; Öhberg, Fredrik; Gerdle, Björn; Grip, Helena

    2016-02-01

    Portable motion systems based on inertial motion sensors are promising methods, with the advantage compared to optoelectronic cameras of not being confined to a laboratory setting. A challenge is to develop relevant outcome measures for clinical use. The aim of this study was to characterize elbow and shoulder motion during functional tasks, using portable motion sensors and a modified Exposure Variation Analysis (EVA) and evaluate system accuracy with optoelectronic cameras. Ten healthy volunteers and one participant with sequel after stroke performed standardised functional arm tasks. Motion was registered simultaneously with a custom developed motion sensor system, including gyroscopes and accelerometers, and an optoelectronic camera system. The EVA was applied on elbow and shoulder joints, and angular and angular velocity EVA plots was calculated. The EVA showed characteristic patterns for each arm task in the healthy controls and a distinct difference between the affected and unaffected arm in the participant with sequel after stroke. The accuracy of the portable system was high with a systematic error ranging between -1.2° and 2.0°. The error was direction specific due to a drift component along the gravity vector. Portable motion sensor systems have high potential as clinical tools for evaluation of arm function. EVA effectively illustrates joint angle and joint angle velocity patterns that may capture deficiencies in arm function and movement quality. Next step will be to manage system drift by including magnetometers, to further develop clinically relevant outcome variables and apply this for relevant patient groups. PMID:26456185

  15. Nonspecific Arm Pain

    PubMed Central

    Moradi, Ali; Ebrahimzadeh, Mohammad H; Ring, David

    2013-01-01

    Nonspecific activity-related arm pain is characterized by an absence of objective physical findings and symptoms that do not correspond with objective pathophysiology. Arm pain without strict diagnosis is often related to activity, work-related activity in particular, and is often seen in patients with physically demanding work. Psychological factors such as catastrophic thinking, symptoms of depression, and heightened illness concern determine a substantial percentage of the disability associated with puzzling hand and arm pains. Ergonomic modifications can help to control symptoms, but optimal health may require collaborative management incorporating psychosocial and psychological elements of illness. PMID:25207288

  16. Fluid Movement and Creativity

    ERIC Educational Resources Information Center

    Slepian, Michael L.; Ambady, Nalini

    2012-01-01

    Cognitive scientists describe creativity as fluid thought. Drawing from findings on gesture and embodied cognition, we hypothesized that the physical experience of fluidity, relative to nonfluidity, would lead to more fluid, creative thought. Across 3 experiments, fluid arm movement led to enhanced creativity in 3 domains: creative generation,…

  17. Playing Active Video Games may not develop movement skills: An intervention trial

    PubMed Central

    Barnett, Lisa M.; Ridgers, Nicola D.; Reynolds, John; Hanna, Lisa; Salmon, Jo

    2015-01-01

    Background: To investigate the impact of playing sports Active Video Games on children's actual and perceived object control skills. Methods: Intervention children played Active Video Games for 6 weeks (1 h/week) in 2012. The Test of Gross Motor Development-2 assessed object control skill. The Pictorial Scale of Perceived Movement Skill Competence assessed perceived object control skill. Repeated measurements of object control and perceived object control were analysed for the whole sample, using linear mixed models, which included fixed effects for group (intervention or control) and time (pre and post) and their interaction. The first model adjusted for sex only and the second model also adjusted for age, and prior ball sports experience (yes/no). Seven mixed-gender focus discussions were conducted with intervention children after programme completion. Results: Ninety-five Australian children (55% girls; 43% intervention group) aged 4 to 8 years (M 6.2, SD 0.95) participated. Object control skill improved over time (p = 0.006) but there was no significant difference (p = 0.913) between groups in improvement (predicted means: control 31.80 to 33.53, SED = 0.748; intervention 30.33 to 31.83, SED = 0.835). A similar result held for the second model. Similarly the intervention did not change perceived object control in Model 1 (predicted means: control: 19.08 to 18.68, SED = 0.362; intervention 18.67 to 18.88, SED = 0.406) or Model 2. Children found the intervention enjoyable, but most did not perceive direct equivalence between Active Video Games and ‘real life’ activities. Conclusions: Whilst Active Video Game play may help introduce children to sport, this amount of time playing is unlikely to build skill. PMID:26844136

  18. 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. PMID:26955753

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

    PubMed

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

    2016-08-01

    Fatigue in ballet dancers may lead to injury, particularly in the lower extremities. However, few studies have investigated the effects of fatigue on ballet dancers' performance and movement patterns. Thus, the current study examines the effect of fatigue on the balance, movement pattern, and muscle activities of the lower extremities in ballet dancers. Twenty healthy, female ballet dancers performed releve on demi-pointe before and after fatigue. The trajectory of the whole body movement and the muscle activities of the major lower extremity muscles were recorded continuously during task performance. The results show that fatigue increases the medial-lateral center of mass (COM) displacement and hip and trunk motion, but decreases the COM velocity and ankle motion. Moreover, fatigue reduces the activities of the hamstrings and tibialis anterior, but increases that of the soleus. Finally, greater proximal hip and trunk motions are applied to compensate for the effects of fatigue, leading to a greater COM movement. Overall, the present findings show that fatigue results in impaired movement control and may therefore increase the risk of dance injury. PMID:27622498

  20. Context-Dependent Neural Activation: Internally and Externally Guided Rhythmic Lower Limb Movement in Individuals With and Without Neurodegenerative Disease.

    PubMed

    Hackney, Madeleine E; Lee, Ho Lim; Battisto, Jessica; Crosson, Bruce; McGregor, Keith M

    2015-01-01

    Parkinson's disease is a neurodegenerative disorder that has received considerable attention in allopathic medicine over the past decades. However, it is clear that, to date, pharmacological and surgical interventions do not fully address symptoms of PD and patients' quality of life. As both an alternative therapy and as an adjuvant to conventional approaches, several types of rhythmic movement (e.g., movement strategies, dance, tandem biking, and Tai Chi) have shown improvements to motor symptoms, lower limb control, and postural stability in people with PD (1-6). However, while these programs are increasing in number, still little is known about the neural mechanisms underlying motor improvements attained with such interventions. Studying limb motor control under task-specific contexts can help determine the mechanisms of rehabilitation effectiveness. Both internally guided (IG) and externally guided (EG) movement strategies have evidence to support their use in rehabilitative programs. However, there appears to be a degree of differentiation in the neural substrates involved in IG vs. EG designs. Because of the potential task-specific benefits of rhythmic training within a rehabilitative context, this report will consider the use of IG and EG movement strategies, and observations produced by functional magnetic resonance imaging and other imaging techniques. This review will present findings from lower limb imaging studies, under IG and EG conditions for populations with and without movement disorders. We will discuss how these studies might inform movement disorders rehabilitation (in the form of rhythmic, music-based movement training) and highlight research gaps. We believe better understanding of lower limb neural activity with respect to PD impairment during rhythmic IG and EG movement will facilitate the development of novel and effective therapeutic approaches to mobility limitations and postural instability. PMID:26696952

  1. Context-Dependent Neural Activation: Internally and Externally Guided Rhythmic Lower Limb Movement in Individuals With and Without Neurodegenerative Disease

    PubMed Central

    Hackney, Madeleine E.; Lee, Ho Lim; Battisto, Jessica; Crosson, Bruce; McGregor, Keith M.

    2015-01-01

    Parkinson’s disease is a neurodegenerative disorder that has received considerable attention in allopathic medicine over the past decades. However, it is clear that, to date, pharmacological and surgical interventions do not fully address symptoms of PD and patients’ quality of life. As both an alternative therapy and as an adjuvant to conventional approaches, several types of rhythmic movement (e.g., movement strategies, dance, tandem biking, and Tai Chi) have shown improvements to motor symptoms, lower limb control, and postural stability in people with PD (1–6). However, while these programs are increasing in number, still little is known about the neural mechanisms underlying motor improvements attained with such interventions. Studying limb motor control under task-specific contexts can help determine the mechanisms of rehabilitation effectiveness. Both internally guided (IG) and externally guided (EG) movement strategies have evidence to support their use in rehabilitative programs. However, there appears to be a degree of differentiation in the neural substrates involved in IG vs. EG designs. Because of the potential task-specific benefits of rhythmic training within a rehabilitative context, this report will consider the use of IG and EG movement strategies, and observations produced by functional magnetic resonance imaging and other imaging techniques. This review will present findings from lower limb imaging studies, under IG and EG conditions for populations with and without movement disorders. We will discuss how these studies might inform movement disorders rehabilitation (in the form of rhythmic, music-based movement training) and highlight research gaps. We believe better understanding of lower limb neural activity with respect to PD impairment during rhythmic IG and EG movement will facilitate the development of novel and effective therapeutic approaches to mobility limitations and postural instability. PMID:26696952

  2. A self-centering active probing technique for kinematic parameter identification and verification of articulated arm coordinate measuring machines

    NASA Astrophysics Data System (ADS)

    Santolaria, J.; Brau, A.; Velázquez, J.; Aguilar, J. J.

    2010-05-01

    A crucial task in the procedure of identifying the parameters of a kinematic model of an articulated arm coordinate measuring machine (AACMM) or robot arm is the process of capturing data. In this paper a capturing data method is analyzed using a self-centering active probe, which drastically reduces the capture time and the required number of positions of the gauge as compared to the usual standard and manufacturer methods. The mathematical models of the self-centering active probe and AACMM are explained, as well as the mathematical model that links the AACMM global reference system to the probe reference system. We present a self-calibration method that will allow us to determine a homogeneous transformation matrix that relates the probe's reference system to the AACMM last reference system from the probing of a single sphere. In addition, a comparison between a self-centering passive probe and self-centering active probe is carried out to show the advantages of the latter in the procedures of kinematic parameter identification and verification of the AACMM.

  3. Rhythmic alternating patterns of brain activity distinguish rapid eye movement sleep from other states of consciousness.

    PubMed

    Chow, Ho Ming; Horovitz, Silvina G; Carr, Walter S; Picchioni, Dante; Coddington, Nate; Fukunaga, Masaki; Xu, Yisheng; Balkin, Thomas J; Duyn, Jeff H; Braun, Allen R

    2013-06-18

    Rapid eye movement (REM) sleep constitutes a distinct "third state" of consciousness, during which levels of brain activity are commensurate with wakefulness, but conscious awareness is radically transformed. To characterize the temporal and spatial features of this paradoxical state, we examined functional interactions between brain regions using fMRI resting-state connectivity methods. Supporting the view that the functional integrity of the default mode network (DMN) reflects "level of consciousness," we observed functional uncoupling of the DMN during deep sleep and recoupling during REM sleep (similar to wakefulness). However, unlike either deep sleep or wakefulness, REM was characterized by a more widespread, temporally dynamic interaction between two major brain systems: unimodal sensorimotor areas and the higher-order association cortices (including the DMN), which normally regulate their activity. During REM, these two systems become anticorrelated and fluctuate rhythmically, in reciprocally alternating multisecond epochs with a frequency ranging from 0.1 to 0.01 Hz. This unique spatiotemporal pattern suggests a model for REM sleep that may be consistent with its role in dream formation and memory consolidation. PMID:23733938

  4. An online brain-machine interface using decoding of movement direction from the human electrocorticogram

    NASA Astrophysics Data System (ADS)

    Milekovic, Tomislav; Fischer, Jörg; Pistohl, Tobias; Ruescher, Johanna; Schulze-Bonhage, Andreas; Aertsen, Ad; Rickert, Jörn; Ball, Tonio; Mehring, Carsten

    2012-08-01

    A brain-machine interface (BMI) can be used to control movements of an artificial effector, e.g. movements of an arm prosthesis, by motor cortical signals that control the equivalent movements of the corresponding body part, e.g. arm movements. This approach has been successfully applied in monkeys and humans by accurately extracting parameters of movements from the spiking activity of multiple single neurons. We show that the same approach can be realized using brain activity measured directly from the surface of the human cortex using electrocorticography (ECoG). Five subjects, implanted with ECoG implants for the purpose of epilepsy assessment, took part in our study. Subjects used directionally dependent ECoG signals, recorded during active movements of a single arm, to control a computer cursor in one out of two directions. Significant BMI control was achieved in four out of five subjects with correct directional decoding in 69%-86% of the trials (75% on average). Our results demonstrate the feasibility of an online BMI using decoding of movement direction from human ECoG signals. Thus, to achieve such BMIs, ECoG signals might be used in conjunction with or as an alternative to intracortical neural signals.

  5. Bionic robot arm with compliant actuators

    NASA Astrophysics Data System (ADS)

    Moehl, Bernhard

    2000-10-01

    Traditional robotics uses non-compliant materials for all components involved in the production of movement. Elasticity is avoided as far as possible, because it leads to hazardous oscillations and makes control of precise movements very difficult. Due to this deliberate stiffness, robots are typically heavy and clumsy structures in comparison to their living counterparts (i.e. man and animals). Yet, moving systems in nature cope not only with the difficulties introduced by compliant materials, they also take advantage of the elasticity in muscles and tendons to produce smooth and even rapid movements. It is understood, that elasticity in a multi-jointed moving system requires sophisticated control mechanisms- as provided by a nervous system or a suitably programmed computer. In this contribution I shall describe a two-jointed robot with purpose-built elasticity in its actuators. This is accomplished by spiral springs places in series with a conventional electric motor and a tendon to the arm. It is shown that, with sufficiently soft elasticity, oscillations can be avoided by active oscillation damping. (Such active oscillation damping presumably also governs movement control in man and animals.) Furthermore, once the major problem has been overcome, elasticity is found to offer a wide spectrum of valuable advantages, as far as the most serious problems in traditional robotics are concerned. They are summarized by terms such as less dangerous, position tolerant, lightweight construction, controlled forces, and ballistic movements. These will be explained in detail and presented for discussion.

  6. Human, Nature, Dynamism: The Effects of Content and Movement Perception on Brain Activations during the Aesthetic Judgment of Representational Paintings

    PubMed Central

    Di Dio, Cinzia; Ardizzi, Martina; Massaro, Davide; Di Cesare, Giuseppe; Gilli, Gabriella; Marchetti, Antonella; Gallese, Vittorio

    2016-01-01

    Movement perception and its role in aesthetic experience have been often studied, within empirical aesthetics, in relation to the human body. No such specificity has been defined in neuroimaging studies with respect to contents lacking a human form. The aim of this work was to explore, through functional magnetic imaging (f MRI), how perceived movement is processed during the aesthetic judgment of paintings using two types of content: human subjects and scenes of nature. Participants, untutored in the arts, were shown the stimuli and asked to make aesthetic judgments. Additionally, they were instructed to observe the paintings and to rate their perceived movement in separate blocks. Observation highlighted spontaneous processes associated with aesthetic experience, whereas movement judgment outlined activations specifically related to movement processing. The ratings recorded during aesthetic judgment revealed that nature scenes received higher scored than human content paintings. The imaging data showed similar activation, relative to baseline, for all stimuli in the three tasks, including activation of occipito-temporal areas, posterior parietal, and premotor cortices. Contrast analyses within aesthetic judgment task showed that human content activated, relative to nature, precuneus, fusiform gyrus, and posterior temporal areas, whose activation was prominent for dynamic human paintings. In contrast, nature scenes activated, relative to human stimuli, occipital and posterior parietal cortex/precuneus, involved in visuospatial exploration and pragmatic coding of movement, as well as central insula. Static nature paintings further activated, relative to dynamic nature stimuli, central and posterior insula. Besides insular activation, which was specific for aesthetic judgment, we found a large overlap in the activation pattern characterizing each stimulus dimension (content and dynamism) across observation, aesthetic judgment, and movement judgment tasks. These

  7. Lateral occipitotemporal cortex (LOTC) activity is greatest while viewing dance compared to visualization and movement: learning and expertise effects.

    PubMed

    Di Nota, Paula M; Levkov, Gabriella; Bar, Rachel; DeSouza, Joseph F X

    2016-07-01

    The lateral occipitotemporal cortex (LOTC) is comprised of subregions selectively activated by images of human bodies (extrastriate body area, EBA), objects (lateral occipital complex, LO), and motion (MT+). However, their role in motor imagery and movement processing is unclear, as are the influences of learning and expertise on its recruitment. The purpose of our study was to examine putative changes in LOTC activation during action processing following motor learning of novel choreography in professional ballet dancers. Subjects were scanned with functional magnetic resonance imaging up to four times over 34 weeks and performed four tasks: viewing and visualizing a newly learned ballet dance, visualizing a dance that was not being learned, and movement of the foot. EBA, LO, and MT+ were activated most while viewing dance compared to visualization and movement. Significant increases in activation were observed over time in left LO only during visualization of the unlearned dance, and all subregions were activated bilaterally during the viewing task after 34 weeks of performance, suggesting learning-induced plasticity. Finally, we provide novel evidence for modulation of EBA with dance experience during the motor task, with significant activation elicited in a comparison group of novice dancers only. These results provide a composite of LOTC activation during action processing of newly learned ballet choreography and movement of the foot. The role of these areas is confirmed as primarily subserving observation of complex sequences of whole-body movement, with new evidence for modification by experience and over the course of real world ballet learning. PMID:26960739

  8. On the asynchronously continuous control of mobile robot movement by motor cortical spiking activity.

    PubMed

    Xu, Zhiming; So, Rosa Q; Toe, Kyaw Kyar; Ang, Kai Keng; Guan, Cuntai

    2014-01-01

    This paper presents an asynchronously intracortical brain-computer interface (BCI) which allows the subject to continuously drive a mobile robot. This system has a great implication for disabled patients to move around. By carefully designing a multiclass support vector machine (SVM), the subject's self-paced instantaneous movement intents are continuously decoded to control the mobile robot. In particular, we studied the stability of the neural representation of the movement directions. Experimental results on the nonhuman primate showed that the overt movement directions were stably represented in ensemble of recorded units, and our SVM classifier could successfully decode such movements continuously along the desired movement path. However, the neural representation of the stop state for the self-paced control was not stably represented and could drift. PMID:25570634

  9. Modeling the postural disturbances caused by upper extremity movements.

    PubMed

    Triolo, R J; Werner, K N; Kirsch, R F

    2001-06-01

    This paper describes the design, validation, and application of a dynamic, three-dimensional (3-D) model of the upper extremity for the purpose of estimating postural disturbances generated by movements of the arms. The model consists of two links representing the upper and lower arms, with the shoulder and elbow modeled as gimbal joints to allow three rotational degrees of freedom. With individualized segment inertial parameters based on anthropometric measurements, the model performs inverse dynamic analysis of recorded arm movements to calculate reaction forces and moments acting on the body at the shoulder in three dimensions. The method was validated by comparing the output of the model to estimates obtained from ground reaction loads during stereotypical and free form unilateral movements at various velocities and with different loads carried by human subjects while seated on biomechanical force platforms. The correlation between predicted and measured reaction forces and moments was very good under all conditions and across all subjects, with average rms errors less than 8% of measured peak-to-peak values. The model was then applied to bimanual activities representative of functional movements that would typically be performed while standing at a counter. The resulting estimates were consistent and adequate for the purpose of evaluating postural disturbances caused by upper extremity movements. PMID:11474966

  10. Robotic Mirror Therapy System for Functional Recovery of Hemiplegic Arms.

    PubMed

    Beom, Jaewon; Koh, Sukgyu; Nam, Hyung Seok; Kim, Wonshik; Kim, Yoonjae; Seo, Han Gil; Oh, Byung-Mo; Chung, Sun Gun; Kim, Sungwan

    2016-01-01

    Mirror therapy has been performed as effective occupational therapy in a clinical setting for functional recovery of a hemiplegic arm after stroke. It is conducted by eliciting an illusion through use of a mirror as if the hemiplegic arm is moving in real-time while moving the healthy arm. It can facilitate brain neuroplasticity through activation of the sensorimotor cortex. However, conventional mirror therapy has a critical limitation in that the hemiplegic arm is not actually moving. Thus, we developed a real-time 2-axis mirror robot system as a simple add-on module for conventional mirror therapy using a closed feedback mechanism, which enables real-time movement of the hemiplegic arm. We used 3 Attitude and Heading Reference System sensors, 2 brushless DC motors for elbow and wrist joints, and exoskeletal frames. In a feasibility study on 6 healthy subjects, robotic mirror therapy was safe and feasible. We further selected tasks useful for activities of daily living training through feedback from rehabilitation doctors. A chronic stroke patient showed improvement in the Fugl-Meyer assessment scale and elbow flexor spasticity after a 2-week application of the mirror robot system. Robotic mirror therapy may enhance proprioceptive input to the sensory cortex, which is considered to be important in neuroplasticity and functional recovery of hemiplegic arms. The mirror robot system presented herein can be easily developed and utilized effectively to advance occupational therapy. PMID:27583794

  11. ARM for Platform Application

    NASA Astrophysics Data System (ADS)

    Patte, Mathieu; Poupat, Jean-Luc; Le Meur, Patrick

    2015-09-01

    The activities described in this paper are part of the CNES R&T “Study of a Cortex-R ARM based architecture” performed by Airbus DS Space System & Electronics in 2014. With the support of CNES, Airbus DS has performed the porting of a representative space application software on an ARM based demonstration platform. This paper presents the platform itself, the activities performed at software level and the first results on this evaluation study.

  12. Mapping the spatio-temporal structure of motor cortical LFP and spiking activities during reach-to-grasp movements

    PubMed Central

    Riehle, Alexa; Wirtssohn, Sarah; Grün, Sonja; Brochier, Thomas

    2013-01-01

    Grasping an object involves shaping the hand and fingers in relation to the object’s physical properties. Following object contact, it also requires a fine adjustment of grasp forces for secure manipulation. Earlier studies suggest that the control of hand shaping and grasp force involve partially segregated motor cortical networks. However, it is still unclear how information originating from these networks is processed and integrated. We addressed this issue by analyzing massively parallel signals from population measures (local field potentials, LFPs) and single neuron spiking activities recorded simultaneously during a delayed reach-to-grasp task, by using a 100-electrode array chronically implanted in monkey motor cortex. Motor cortical LFPs exhibit a large multi-component movement-related potential (MRP) around movement onset. Here, we show that the peak amplitude of each MRP component and its latency with respect to movement onset vary along the cortical surface covered by the array. Using a comparative mapping approach, we suggest that the spatio-temporal structure of the MRP reflects the complex physical properties of the reach-to-grasp movement. In addition, we explored how the spatio-temporal structure of the MRP relates to two other measures of neuronal activity: the temporal profile of single neuron spiking activity at each electrode site and the somatosensory receptive field properties of single neuron activities. We observe that the spatial representations of LFP and spiking activities overlap extensively and relate to the spatial distribution of proximal and distal representations of the upper limb. Altogether, these data show that, in motor cortex, a precise spatio-temporal pattern of activation is involved for the control of reach-to-grasp movements and provide some new insight about the functional organization of motor cortex during reaching and object manipulation. PMID:23543888

  13. The Effects of Constraint-Induced Movement Therapy on Activities Important to Independent School Participation of Children with Hemiparesis

    ERIC Educational Resources Information Center

    Carney, Joan

    2012-01-01

    This study investigated the efficacy of constraint-induced movement therapy (CI therapy) on activities important to school participation in children with hemiparesis. Four children, ages 4-0 to 7-10 participated in an intensive CI therapy program in a clinical setting. Constraining casts were worn 24 hours daily. Therapy was delivered 6 hours…

  14. Social Movement Oriented Citizenship in Colombia: The Effects of Curriculum, Pedagogy and Extra-Curricular Activities on Student Orientation

    ERIC Educational Resources Information Center

    Edwards, D. Brent, Jr.

    2012-01-01

    Social movement oriented citizenship (SMOC) centers on peaceful protest, proactive community involvement and participation in activities to support human rights and environmental protection. Research generally on SMOC is extremely limited; even more so is research that analyses the influence of school- and student-level, policy-relevant variables…

  15. Great Lakes Climate and Water Movement. Earth Systems - Education Activities for Great Lakes Schools (ES-EAGLS).

    ERIC Educational Resources Information Center

    Miller, Heidi, Ed.; Sheaffer, Amy L., Ed.

    This activity book is part of a series designed to take a concept or idea from the existing school curriculum and develop it in the context of the Great Lakes using teaching approaches and materials appropriate for students in middle and high school. The theme of this book is Great Lakes climate and water movement. Students learn about land-sea…

  16. Some possible applications of measurements on mu mesons to nuclear safeguards, nonproliferation, and arms control activities

    SciTech Connect

    Kane, W.R.; Vanier, P.E.

    1997-10-01

    In the nuclear safeguards and arms control areas, well-developed methodologies exist for determining the properties of nuclear materials via measurements of the gamma rays and neutrons emitted from these materials, or in the arms control area, by the use of radiography. In certain favorable instances, it may by feasible to perform comparable measurements with the use of a ubiquitous, naturally-occurring radiation--cosmic ray mu mesons (muons). At the earth`s surface these charged particles have a broad energy distribution peaking at about 500 MeV with a flux of approximately 10{sup {minus}2}/cm{sup 2}-sec-steradian. In traversing matter, muons lose energy at a rate of approximately 2 MeV/gram almost independent of atomic number. Muons can readily be detected by either plastic scintillators or wire planes. While the flux is small, a scintillator of one meter area, for example, will register about 20,000 events/min. these particles should have utility in the detection and imaging of objects with sectional densities of a few hundred grams/cm{sup 2}. The degree of intrusiveness of the imaging can be controlled through the detector configuration. Some possible applications include: (1) mass measurements on large UF{sub 6} cylinders, (2) determination of the size of treaty-limited objects, e.g., missiles, in rail cars or other containment; (3) verification of single or multiple warheads or components; (4) the detection of concealed, underground cavities. Examples will be presented.

  17. Modulations of mirroring activity by desire for social connection and relevance of movement.

    PubMed

    Aragón, Oriana R; Sharer, Elizabeth A; Bargh, John A; Pineda, Jaime A

    2014-11-01

    Mirroring neurons fire both when an individual moves and observes another move in kind. This simulation of others' movements is thought to effortlessly and ubiquitously support empathetic connection and social understanding. However, at times this could be maladaptive. How could a boxer mirror a losing opponent's expressions of fatigue, feeling his weariness, precisely when strength is required? Clearly, the boxer must emotionally disconnect from his opponent and those expressions of fatigue must become irrelevant and not mirrored. But, movements that inform of his opponent's intentions to deliver an incoming blow are quite relevant and still should require mirroring. We tested these dimensions of emotional connectedness and relevance of movement in an electroencephalography experiment, where participants' desires to socially connect with a confederate were manipulated. Before manipulation, all participants mirrored the confederate's purely kinematic (a hand opening and closing) and goal-directed (a hand opening and closing around a token that the participant desired) hand movements. After manipulation, unfairly treated subjects ceased to mirror the purely kinematic movements but continued to mirror goal-relevant movements. Those treated fairly continued to mirror all movements. The results suggest that social mirroring can be adaptive in order to meet the demands of a varied social environment. PMID:24194581

  18. Development of a prototype movement assistance system for extravehicular activity gloves

    NASA Astrophysics Data System (ADS)

    Hill, Tyler N.

    Spacesuits utilized a rubberized layer of material to contain a pressurized atmosphere to facilitate respiration and maintain the physiologic functions of the astronaut residing within. However, the elasticity of the material makes it resistant to deformation increasing the amount of work required during movement. This becomes particularly fatiguing for the muscle groups controlling the motion of the hands and fingers. To mitigate this a robotic system was proposed and developed. The system built upon previous concepts and prototypes discovered through research efforts. It utilized electric motors to pull the index, ring, and middle fingers of the right hand closed, ideally overcoming the resistive force posed by the pressurized elastic material. The effect of the system was determined by comparing qualitative and quantitative data obtained during activities conducted with and without it within a glove box. It was found that the system was able to offload some of this elastic force though several characteristics of the design limited the full potential this device offered. None the less, the project was met with success and provides a solid platform for continued research and development.

  19. Coordination of human upper arm and forearm motion in rapid extensions

    NASA Technical Reports Server (NTRS)

    Nahvi, Mahmood

    1991-01-01

    In many movements of the upper limb such as reaching, positioning, and displacing the objects, the hand moves smoothly along a uni-directional planar trajectory with a bell-shaped speed profile. Because of variability of the load, gravitational and velocity interaction forces between its segments, the dynamics of the arm during the motion is very complex. Motion of the upper arm and the forearm are coordinated to produce smooth movements despite such complex dynamics. This coordination constitutes an important organizational feature of arm movement. The present paper describes some experimental results related to the above and interprets their role in producing smooth motion of the hand. Trajectories of the right upper limb in vertical plane and the simultaneous muscles' EMG activities were recorded for extensions of various amplitudes under four loads. The forearm trajectories are smooth with bell-shaped speed profiles. The upper arm trajectories may have bimodal speed profiles and three segments, resembling an inverted 'Z.' Segmentation is sharper for the points near the shoulder joint, and is accentuated by load. As one moves from the central points near the shoulder joint to the peripheral points near the hand, the three segments merge and result in smooth curves with single-peaked speed profiles. The three segments have a coherent time course and can be identified rather accurately and non-ambiguously. The observed trajectories and the EMG patterns reveal an effective coordination strategy which utilizes the structure and the dynamics of the moving arm to produce smooth movement.

  20. Movement Disorders

    MedlinePlus

    ... t want them to. If you have a movement disorder, you experience these kinds of impaired movement. Dyskinesia ... movement and is a common symptom of many movement disorders. Tremors are a type of dyskinesia. Nerve diseases ...

  1. Tectonic Plate Movement.

    ERIC Educational Resources Information Center

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  2. A review of assistive devices for arm balancing.

    PubMed

    Dunning, A G; Herder, J L

    2013-06-01

    Due to neuromuscular disorders (e.g., Duchenne Muscular Dystrophy) people often loose muscle strength and become wheelchair bound. It is important to use muscles as much as possible. To allow this, and to increase independency of patients, an arm orthosis can be used to perform activities of daily life. The orthosis compensates for the gravity force of the arm, allowing people to perform movements with smaller muscle forces. For patients, the aesthetics of the orthosis is one of the critical issues. This paper presents the state-of-the-art in passive and wearable active arm orthoses, and investigates how to proceed towards a suitable structure for a wearable passive arm orthosis, that is able to balance the arm within its natural range of motion and is inconspicuous; in the ideal case it fits underneath the clothes. Existing devices were investigated with respect to the body interface, the volume, and the workspace. According to these evaluation metrics it is investigated to what extent the devices are wearable and inconspicuous. Furthermore, the balancing principle of the devices, the architecture, force transmission through the devices, and alignment with the body joints are investigated. It appears that there is only one wearable passive orthosis presented in literature. This orthosis can perform throughout the natural workspace of the arm, but is still too bulky to be inconspicuous. The other passive orthoses were conspicuous and mounted to the wheelchair. Except one, the wearable active orthoses were all conspicuous and heavy due to a large backpack to enclose the actuators. They also could not achieve the entire natural workspace of the human arm. A future design of an inconspicuous, wearable, passive arm orthoses should stay close to the body, be comfortable to wear, and supports pronation and supination. PMID:24187302

  3. Sensorimotor organization of a sustained involuntary movement

    PubMed Central

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

    2015-01-01

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

  4. A single session of open kinetic chain movements emphasizing speed improves speed of movement and modifies postural control in stroke.

    PubMed

    Gray, Vicki L; Ivanova, Tanya D; Garland, S Jayne

    2016-01-01

    Little attention has been given to training speed of movement, even though functional activities require quick submaximal contractions. Closed kinetic chain (CKC) exercises are considered more functional; however, the best method for training speed is not known. A single bout of open kinetic chain (OKC) exercises emphasizing speed was performed to determine whether movement velocity and muscle activation would improve in a single session and whether the improvements transfer to a physiological balance task. Eleven participants <1 year post-stroke performed an arm raise task before and after a single session of fast OKC exercises. Surface electromyography (EMG) from soleus (SOL), tibialis anterior (TA), biceps femoris (BF) and rectus femoris (RF) muscles, peak velocity and average power were recorded during the OKC exercises. EMG from SOL, TA, BF and RF and center of pressure (COP) velocity were measured during arm raise task. At the end of the OKC exercises, velocity, power and TA, BF and RF EMG area increased. The arm acceleration and BF EMG area increased significantly during the arm raise. The improvements observed at the end of the OKC exercises transferred to the arm raise task. The improvements in balance were comparable to those previously seen after CKC exercises. PMID:26863374

  5. A Systematic Review of the Effectiveness of Physical Education and School Sport Interventions Targeting Physical Activity, Movement Skills and Enjoyment of Physical Activity

    ERIC Educational Resources Information Center

    Dudley, Dean; Okely, Anthony; Pearson, Philip; Cotton, Wayne

    2011-01-01

    This article presents a systematic review of published literature on the effectiveness of physical education in promoting participation in physical activity, enjoyment of physical activity and movement skill proficiency in children and adolescents. The review utilized a literature search, specifically publications listed in Ovid, A+ Education,…

  6. From convenience to hazard: a short history of the emergence of the menstrual activism movement, 1971-1992.

    PubMed

    Bobel, Chris

    2008-08-01

    In this article, I explore the early history of contemporary menstrual activism in the United States by looking through the lens of the first seven editions of the feminist women's health classic, Our Bodies, Ourselves (OBOS). This analysis illustrates the development of a critical menstrual consciousness as three key phases of the emerging movement, offers a representation of the dynamic nature of feminist health consciousness, and highlights the importance of linking current activism to its past. PMID:18663632

  7. Nitrergic ventro-medial medullary neurons activated during cholinergically induced active (rapid eye movement) sleep in the cat.

    PubMed

    Pose, I; Sampogna, S; Chase, M H; Morales, F R

    2011-01-13

    The rostral ventro-medial medullary reticular formation is a complex structure that is involved with a variety of motor functions. It contains glycinergic neurons that are activated during active (rapid eye movement (REM)) sleep (AS); these neurons appear to be responsible for the postsynaptic inhibition of motoneurons that occurs during this state. We have reported that neurons in this same region contain nitric oxide (NO) synthase and that they innervate brainstem motor pools. In the present study we examined the c-fos expression of these neurons after carbachol-induced active sleep (C-AS). Three control and four experimental cats were employed to identify c-fos expressing nitrergic neurons using immunocytochemical techniques to detect the Fos protein together with neuronal nitric oxide synthase (nNOS) or nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase activity. The classical neurotransmitter content of the nitrergic cells in this region was examined through the combination of immunocytochemical techniques for the detection of glutamate, glycine, choline acetyltransferase (ChAT), tyrosine hydroxilase (TH) or GABA together with nNOS. During C-AS, there was a 1074% increase in the number of nitrergic neurons that expressed c-fos. These neurons did not contain glycine, ChAT, TH or GABA, but a subpopulation (15%) of them displayed glutamate-like immunoreactivity. Therefore, some of these neurons contain both an excitatory neurotransmitter (glutamate) and an excitatory neuromodulator (NO); the neurotransmitter content of the rest of them remains to be determined. Because some of the nitrergic neurons innervate brainstem motoneurons it is possible that they participate in the generation of tonic and excitatory phasic motor events that occur during AS. We also suggest that these nitrergic neurons may be involved in autonomic regulation during this state. In addition, because NO has trophic effects on target neurons, the present findings represent the

  8. A new high-speed visual stimulation method for gaze-contingent eye movement and brain activity studies.

    PubMed

    Richlan, Fabio; Gagl, Benjamin; Schuster, Sarah; Hawelka, Stefan; Humenberger, Josef; Hutzler, Florian

    2013-01-01

    Approaches using eye movements as markers of ongoing brain activity to investigate perceptual and cognitive processes were able to implement highly sophisticated paradigms driven by eye movement recordings. Crucially, these paradigms involve display changes that have to occur during the time of saccadic blindness, when the subject is unaware of the change. Therefore, a combination of high-speed eye tracking and high-speed visual stimulation is required in these paradigms. For combined eye movement and brain activity studies (e.g., fMRI, EEG, MEG), fast and exact timing of display changes is especially important, because of the high susceptibility of the brain to visual stimulation. Eye tracking systems already achieve sampling rates up to 2000 Hz, but recent LCD technologies for computer screens reduced the temporal resolution to mostly 60 Hz, which is too slow for gaze-contingent display changes. We developed a high-speed video projection system, which is capable of reliably delivering display changes within the time frame of < 5 ms. This could not be achieved even with the fastest cathode ray tube (CRT) monitors available (< 16 ms). The present video projection system facilitates the realization of cutting-edge eye movement research requiring reliable high-speed visual stimulation (e.g., gaze-contingent display changes, short-time presentation, masked priming). Moreover, this system can be used for fast visual presentation in order to assess brain activity using various methods, such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). The latter technique was previously excluded from high-speed visual stimulation, because it is not possible to operate conventional CRT monitors in the strong magnetic field of an MRI scanner. Therefore, the present video projection system offers new possibilities for studying eye movement-related brain activity using a combination of eye tracking and fMRI. PMID:23847475

  9. Canadian 24-Hour Movement Guidelines for Children and Youth: An Integration of Physical Activity, Sedentary Behaviour, and Sleep.

    PubMed

    Tremblay, Mark S; Carson, Valerie; Chaput, Jean-Philippe; Connor Gorber, Sarah; Dinh, Thy; Duggan, Mary; Faulkner, Guy; Gray, Casey E; Gruber, Reut; Janson, Katherine; Janssen, Ian; Katzmarzyk, Peter T; Kho, Michelle E; Latimer-Cheung, Amy E; LeBlanc, Claire; Okely, Anthony D; Olds, Timothy; Pate, Russell R; Phillips, Andrea; Poitras, Veronica J; Rodenburg, Sophie; Sampson, Margaret; Saunders, Travis J; Stone, James A; Stratton, Gareth; Weiss, Shelly K; Zehr, Lori

    2016-06-01

    Leaders from the Canadian Society for Exercise Physiology convened representatives of national organizations, content experts, methodologists, stakeholders, and end-users who followed rigorous and transparent guideline development procedures to create the Canadian 24-Hour Movement Guidelines for Children and Youth: An Integration of Physical Activity, Sedentary Behaviour, and Sleep. These novel guidelines for children and youth aged 5-17 years respect the natural and intuitive integration of movement behaviours across the whole day (24-h period). The development process was guided by the Appraisal of Guidelines for Research Evaluation (AGREE) II instrument and systematic reviews of evidence informing the guidelines were assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Four systematic reviews (physical activity, sedentary behaviour, sleep, integrated behaviours) examining the relationships between and among movement behaviours and several health indicators were completed and interpreted by expert consensus. Complementary compositional analyses were performed using Canadian Health Measures Survey data to examine the relationships between movement behaviours and health indicators. A stakeholder survey was employed (n = 590) and 28 focus groups/stakeholder interviews (n = 104) were completed to gather feedback on draft guidelines. Following an introductory preamble, the guidelines provide evidence-informed recommendations for a healthy day (24 h), comprising a combination of sleep, sedentary behaviours, light-, moderate-, and vigorous-intensity physical activity. Proactive dissemination, promotion, implementation, and evaluation plans have been prepared in an effort to optimize uptake and activation of the new guidelines. Future research should consider the integrated relationships among movement behaviours, and similar integrated guidelines for other age groups should be developed. PMID:27306437

  10. How ‘arm-twisting’ by the inducer triggers activation of the MalT transcription factor, a typical signal transduction ATPase with numerous domains (STAND)

    PubMed Central

    Danot, Olivier

    2015-01-01

    Signal transduction ATPases with numerous domains (STAND) get activated through inducer-dependent assembly into multimeric platforms. This switch relies on the conversion of their nucleotide-binding oligomerization domain (NOD) from a closed, ADP-bound form to an open, ATP-bound form. The NOD closed form is stabilized by contacts with the arm, a domain that connects the NOD to the inducer-binding domain called the sensor. How the inducer triggers NOD opening remains unclear. Here, I pinpointed the NOD-arm interface of the MalT STAND transcription factor, and I generated a MalT variant in which this interface can be covalently locked on demand, thereby trapping the NOD in the closed state. By characterizing this locked variant, I found that the inducer is recognized in two steps: it first binds to the sole sensor with low affinity, which then triggers the recruitment of the arm to form a high-affinity arm-sensor inducer-binding site. Strikingly, this high-affinity binding step was incompatible with arm-NOD contacts maintaining the NOD closed. Through this toggling between two mutually exclusive states reminiscent of a single-pole double-throw switch, the arm couples inducer binding to NOD opening, shown here to precede nucleotide exchange. This scenario likely holds for other STANDs like mammalian NLR innate immunity receptors. PMID:25740650

  11. PLD1 regulates Xenopus convergent extension movements by mediating Frizzled7 endocytosis for Wnt/PCP signal activation.

    PubMed

    Lee, Hyeyoon; Lee, Seung Joon; Kim, Gun-Hwa; Yeo, Inchul; Han, Jin-Kwan

    2016-03-01

    Phospholipase D (PLD) is involved in the regulation of receptor-associated signaling, cell movement, cell adhesion and endocytosis. However, its physiological role in vertebrate development remains poorly understood. In this study, we show that PLD1 is required for the convergent extension (CE) movements during Xenopus gastrulation by activating Wnt/PCP signaling. Xenopus PLD1 protein is specifically enriched in the dorsal region of Xenopus gastrula embryo and loss or gain-of-function of PLD1 induce defects in gastrulation and CE movements. These defective phenotypes are due to impaired regulation of Wnt/PCP signaling pathway. Biochemical and imaging analysis using Xenopus tissues reveal that PLD1 is required for Fz7 receptor endocytosis upon Wnt11 stimulation. Moreover, we show that Fz7 endocytosis depends on dynamin and regulation of GAP activity of dynamin by PLD1 via its PX domain is crucial for this process. Taken together, our results suggest that PLD1 acts as a new positive mediator of Wnt/PCP signaling by promoting Wnt11-induced Fz7 endocytosis for precise regulation of Xenopus CE movements. PMID:26806705

  12. Brain activation is related to smoothness of upper limb movements after stroke.

    PubMed

    Buma, Floor E; van Kordelaar, Joost; Raemaekers, Matthijs; van Wegen, Erwin E H; Ramsey, Nick F; Kwakkel, Gert

    2016-07-01

    It is unclear whether additionally recruited sensorimotor areas in the ipsilesional and contralesional hemisphere and the cerebellum can compensate for lost neuronal functions after stroke. The objective of this study was to investigate how increased recruitment of secondary sensorimotor areas is associated with quality of motor control after stroke. In seventeen patients (three females, fourteen males; age: 59.9 ± 12.6 years), cortical activation levels were determined with functional magnetic resonance imaging (fMRI) in 12 regions of interest during a finger flexion-extension task in weeks 6 and 29 after stroke. At the same time points and by using 3D kinematics, the quality of motor control was assessed by smoothness of the grasp aperture during a reach-to-grasp task, quantified by normalized jerk. Ipsilesional premotor cortex, insula and cerebellum, as well as the contralesional supplementary motor area, insula and cerebellum, correlated significantly and positively with the normalized jerk of grasp aperture at week 6 after stroke. A positive trend towards this correlation was observed in week 29. This study suggests that recruitment of secondary motor areas at 6 weeks after stroke is highly associated with increased jerk during reaching and grasping. As jerk represents the change in acceleration, the recruitment of additional sensorimotor areas seems to reflect a type of control in which deviations from an optimal movement pattern are continuously corrected. This relationship suggests that additional recruitment of sensorimotor areas after stroke may not correspond to restitution of motor function, but more likely to adaptive motor learning strategies to compensate for motor impairments. PMID:26979435

  13. Head movements suggest canal and otolith projections are activated during galvanic vestibular stimulation.

    PubMed

    Kim, J

    2013-12-01

    Three-dimensional changes in the angular orientation of the head were monitored during galvanic vestibular stimulation (GVS) delivered through electrodes implanted bilaterally in the tensor tympani muscle of the guinea-pig middle ear. Bilateral GVS was delivered by passing current between both ears with the anode situated in one ear and the cathode in the other ear. Unilateral GVS was also delivered between one ear and an indifferent electrode on the skull. Constant-current stimulation caused the head to tilt predominantly within the roll and yaw planes toward an ear stimulated with anodal current and away from an ear stimulated with cathodal current. No significant head tilt in the pitch plane was observed with either bilateral or unilateral GVS. Bilateral GVS was found to induce significantly greater roll head tilt (RHT) and yaw head tilt (YHT) than the same intensity of unilateral anodal or cathodal GVS, but not the sum of responses induced by the two polarities of unilateral GVS. Significant asymmetries were observed in the responses of YHT and RHT for unilateral anodal and cathodal GVS; unilateral cathodal stimulation generated greater head deviation compared with the same intensity of unilateral anodal stimulation. These asymmetric responses are consistent with activation of irregularly discharging afferents, which have been shown previously to exhibit asymmetric responses for anodal and cathodal GVS (Kim and Curthoys, 2004). Together with the observations of previous guinea-pig studies, the results suggest that head movements induced by GVS may be mediated by irregularly discharging afferents innervating the otoliths, and possibly the horizontal semicircular canals. PMID:24021920

  14. Snowballing movement. Legislators are now active advocates regarding population and development.

    PubMed

    De Leon, B D

    1992-08-01

    Newly industrializing economies (NIEs) in East Asia have demonstrated that the population programs were part of their economic success, such as in Thailand and Indonesia where family planning (FP) was made a way of life. The population growth in the Philippines has put pressure on the environment by migration to uplands where slash-and-burn agriculture adds to deforestation. The Global Committee of Parliamentarians of Population and Development headquartered in New York serves as a liaison for 56 legislative groups sponsoring meetings and seminars. In October 1981 the Asian Conference on Parliamentarians on Population and Development was held in Beijing with the participation of legislators from 19 countries. It set up the Asian Forum for Parliamentarians on Population and Development to contribute and promote activities that facilitate population and development, and to improve the living standards and welfare of people in Asia. The Secretariat is located in Bangkok, Thailand. In October 1987 in Beijing and in October 1990 follow-up regional conferences were organized. The latter was attended by 21 Asian parliamentarians who endorsed the stabilization of population growth to achieve a 1% growth rate for Asia by 2000. The Philippine population numbered 63.9 million in mid-1992 with an annual growth rate of 2.3%. The Philippine House of Representatives started an inquiry about the disturbing demographic trends with implications on economic growth. In 1987 a movement commenced that hosted the Philippine Parliamentarians Conference on Human Survival, Population and Development (PARLCON '88) in Manila. It focused on sustainable development, the conditions of women and children, the environment, and the promotion of FP which was adopted by the House and involved a major segment of legislators. PMID:12343890

  15. Changes in force associated with the amount of aligner activation and lingual bodily movement of the maxillary central incisor

    PubMed Central

    Li, Xiaowei; Ren, Chaochao; Wang, Zheyao; Zhao, Pai; Wang, Hongmei

    2016-01-01

    Objective The purposes of this study were to measure the orthodontic forces generated by thermoplastic aligners and investigate the possible influences of different activations for lingual bodily movements on orthodontic forces, and their attenuation. Methods Thermoplastic material of 1.0-mm in thickness was used to manufacture aligners for 0.2, 0.3, 0.4, 0.5, and 0.6 mm activations for lingual bodily movements of the maxillary central incisor. The orthodontic force in the lingual direction delivered by the thermoplastic aligners was measured using a micro-stress sensor system for the invisible orthodontic technique, and was monitored for 2 weeks. Results Orthodontic force increased with the amount of activation of the aligner in the initial measurements. The attenuation speed in the 0.6 mm group was faster than that of the other groups (p < 0.05). All aligners demonstrated rapid relaxation in the first 8 hours, which then decreased slowly and plateaued on day 4 or 5. Conclusions The amount of activation had a substantial influence on the orthodontic force imparted by the aligners. The results suggest that the activation of lingual bodily movement of the maxillary central incisor should not exceed 0.5 mm. The initial 4 or 5 days is important with respect to orthodontic treatment incorporating an aligner. PMID:27019820

  16. A model for learning human reaching movements.

    PubMed

    Karniel, A; Inbar, G F

    1997-09-01

    Reaching movement is a fast movement towards a given target. The main characteristics of such a movement are straight path and a bell-shaped speed profile. In this work a mathematical model for the control of the human arm during ballistic reaching movements is presented. The model of the arm contains a 2 degrees of freedom planar manipulator, and a Hill-type, non-linear mechanical model of six muscles. The arm model is taken from the literature with minor changes. The nervous system is modeled as an adjustable pattern generator that creates the control signals to the muscles. The control signals in this model are rectangular pulses activated at various amplitudes and timings, that are determined according to the given target. These amplitudes and timings are the parameters that should be related to each target and initial conditions in the work-space. The model of the nervous system consists of an artificial neural net that maps any given target to the parameter space of the pattern generator. In order to train this net, the nervous system model includes a sensitivity model that transforms the error from the arm end-point coordinates to the parameter coordinates. The error is assessed only at the termination of the movement from knowledge of the results. The role of the non-linearity in the muscle model and the performance of the learning scheme are analysed, illustrated in simulations and discussed. The results of the present study demonstrate the central nervous system's (CNS) ability to generate typical reaching movements with a simple feedforward controller that controls only the timing and amplitude of rectangular excitation pulses to the muscles and adjusts these parameters based on knowledge of the results. In this scheme, which is based on the adjustment of only a few parameters instead of the whole trajectory, the dimension of the control problem is reduced significantly. It is shown that the non-linear properties of the muscles are essential to achieve

  17. Motor Cortical Correlates of Arm Resting in the Context of a Reaching Task and Implications for Prosthetic Control

    PubMed Central

    Kennedy, Scott D.; Schwartz, Andrew B.; Whitford, Andrew S.; Sohn, Jeong-Woo; McMorland, Angus J.C.

    2014-01-01

    Prosthetic devices are being developed to restore movement for motor-impaired individuals. A robotic arm can be controlled based on models that relate motor-cortical ensemble activity to kinematic parameters. The models are typically built and validated on data from structured trial periods during which a subject actively performs specific movements, but real-world prosthetic devices will need to operate correctly during rest periods as well. To develop a model of motor cortical modulation during rest, we trained monkeys (Macaca mulatta) to perform a reaching task with their own arm while recording motor-cortical single-unit activity. When a monkey spontaneously put its arm down to rest between trials, our traditional movement decoder produced a nonzero velocity prediction, which would cause undesired motion when applied to a prosthetic arm. During these rest periods, a marked shift was found in individual units' tuning functions. The activity pattern of the whole population during rest (Idle state) was highly distinct from that during reaching movements (Active state), allowing us to predict arm resting from instantaneous firing rates with 98% accuracy using a simple classifier. By cascading this state classifier and the movement decoder, we were able to predict zero velocity correctly, which would avoid undesired motion in a prosthetic application. Interestingly, firing rates during hold periods followed the Active pattern even though hold kinematics were similar to those during rest with near-zero velocity. These findings expand our concept of motor-cortical function by showing that population activity reflects behavioral context in addition to the direct parameters of the movement itself. PMID:24760860

  18. Physiological modules for generating discrete and rhythmic movements: action identification by a dynamic recurrent neural network

    PubMed Central

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

    2014-01-01

    In this study we employed a dynamic recurrent neural network (DRNN) in a novel fashion to reveal characteristics of control modules underlying the generation of muscle activations when drawing figures with the outstretched arm. We asked healthy human subjects to perform four different figure-eight movements in each of two workspaces (frontal plane and sagittal plane). We then trained a DRNN to predict the movement of the wrist from information in the EMG signals from seven different muscles. We trained different instances of the same network on a single movement direction, on all four movement directions in a single movement plane, or on all eight possible movement patterns and looked at the ability of the DRNN to generalize and predict movements for trials that were not included in the training set. Within a single movement plane, a DRNN trained on one movement direction was not able to predict movements of the hand for trials in the other three directions, but a DRNN trained simultaneously on all four movement directions could generalize across movement directions within the same plane. Similarly, the DRNN was able to reproduce the kinematics of the hand for both movement planes, but only if it was trained on examples performed in each one. As we will discuss, these results indicate that there are important dynamical constraints on the mapping of EMG to hand movement that depend on both the time sequence of the movement and on the anatomical constraints of the musculoskeletal system. In a second step, we injected EMG signals constructed from different synergies derived by the PCA in order to identify the mechanical significance of each of these components. From these results, one can surmise that discrete-rhythmic movements may be constructed from three different fundamental modules, one regulating the co-activation of all muscles over the time span of the movement and two others elliciting patterns of reciprocal activation operating in orthogonal directions

  19. Enhancing activities of daily living of chronic stroke patients in primary health care by modified constraint-induced movement therapy (HOMECIMT): study protocol for a cluster randomized controlled trial

    PubMed Central

    2013-01-01

    Background Stroke leads to constant rehabilitation needs even at the chronic stage. However, although many stroke patients receive physical or occupational therapy in primary health care, treatment prescriptions do not generally specify therapeutic goals; in particular, participation is not established as an explicit therapeutic goal in the ambulatory setting. The primary aim of this study is to evaluate the efficacy of a therapy regimen for chronic stroke patients (modified ‘constraint-induced movement therapy (CIMT) at home’) with impaired hand or arm function with regard to the prerequisites of participation in everyday activities: a sufficient arm and hand function. ‘CIMT at home’ will be compared with conventional physical and occupational therapy (‘therapy as usual’). Methods/design The study is a parallel cluster randomized controlled trial with therapy practices as clusters (n = 48). After written consent from the patients (n = 144), the therapists will be randomly assigned to treat either the intervention or the control group. Blinded external assessors will evaluate the patients using standardized outcome measures before and after the intervention, and six months later. The two coprimary endpoint assessments of arm and hand function as prerequisites for participation (defined as equal involvement in activities of daily living) are the motor activity log (quality of arm and hand use) and the Wolf motor function test (arm and hand function). These assessments are made four weeks post-treatment and relativized to baseline performance. Changes in primary outcomes will be analyzed with mixed models, which consider the hierarchical structure of the data and will be adjusted to the baseline measurements and sex. The primary analysis will be the comparison of the two randomized groups, with respect to the adjusted averages for each of the two coprimary endpoints. To keep an overall significance level of 5%, the two endpoints will be tested at the

  20. Robotic Arm Manipulator Using Active Control for Sample Acquisition and Transfer, and Passive Mode for Surface Compliance

    NASA Technical Reports Server (NTRS)

    Liu, Jun; Underhill, Michael L.; Trease, Brian P.; Lindemann, Randel A.

    2010-01-01

    A robotic arm that consists of three joints with four degrees of freedom (DOF) has been developed. It can carry an end-effector to acquire and transfer samples by using active control and comply with surface topology in a passive mode during a brief surface contact. The three joints are arranged in such a way that one joint of two DOFs is located at the shoulder, one joint of one DOF is located at the elbow, and one joint of one DOF is located at the wrist. Operationally, three DOFs are moved in the same plane, and the remaining one on the shoulder is moved perpendicular to the other three for better compliance with ground surface and more flexibility of sample handling. Three out of four joints are backdriveable, making the mechanism less complex and more cost effective

  1. Whisker Movements Reveal Spatial Attention: A Unified Computational Model of Active Sensing Control in the Rat

    PubMed Central

    Mitchinson, Ben; Prescott, Tony J.

    2013-01-01

    Spatial attention is most often investigated in the visual modality through measurement of eye movements, with primates, including humans, a widely-studied model. Its study in laboratory rodents, such as mice and rats, requires different techniques, owing to the lack of a visual fovea and the particular ethological relevance of orienting movements of the snout and the whiskers in these animals. In recent years, several reliable relationships have been observed between environmental and behavioural variables and movements of the whiskers, but the function of these responses, as well as how they integrate, remains unclear. Here, we propose a unifying abstract model of whisker movement control that has as its key variable the region of space that is the animal's current focus of attention, and demonstrate, using computer-simulated behavioral experiments, that the model is consistent with a broad range of experimental observations. A core hypothesis is that the rat explicitly decodes the location in space of whisker contacts and that this representation is used to regulate whisker drive signals. This proposition stands in contrast to earlier proposals that the modulation of whisker movement during exploration is mediated primarily by reflex loops. We go on to argue that the superior colliculus is a candidate neural substrate for the siting of a head-centred map guiding whisker movement, in analogy to current models of visual attention. The proposed model has the potential to offer a more complete understanding of whisker control as well as to highlight the potential of the rodent and its whiskers as a tool for the study of mammalian attention. PMID:24086120

  2. Mapping phantom movement representations in the motor cortex of amputees.

    PubMed

    Mercier, Catherine; Reilly, Karen T; Vargas, Claudia D; Aballea, Antoine; Sirigu, Angela

    2006-08-01

    Limb amputation results in plasticity of connections between the brain and muscles, with the cortical motor representation of the missing limb seemingly shrinking, to the presumed benefit of remaining body parts that have cortical representations adjacent to the now-missing limb. Surprisingly, the corresponding perceptual representation does not suffer a similar fate but instead persists as a phantom limb endowed with sensory and motor qualities. How can cortical reorganization after amputation be reconciled with the maintenance of a motor representation of the phantom limb in the brain? In an attempt to answer this question we explored the relationship between the cortical representation of the remaining arm muscles and that of phantom movements. Using transcranial magnetic stimulation (TMS) we systematically mapped phantom movement perceptions while simultaneously recording stump muscle activity in three above-elbow amputees. TMS elicited sensations of movement in the phantom hand when applied over the presumed hand area of the motor cortex. In one subject the amplitude of the perceived movement was positively correlated with the intensity of stimulation. Interestingly, phantom limb movements that the patient could not produce voluntarily were easily triggered by TMS, suggesting that the inability to voluntarily move the phantom is not equivalent to a loss of the corresponding movement representation. We suggest that hand movement representations survive in the reorganized motor area of amputees even when these cannot be directly accessed. The activation of these representations is probably necessary for the experience of phantom movement. PMID:16844715

  3. Decoding the individual finger movements from single-trial functional magnetic resonance imaging recordings of human brain activity.

    PubMed

    Shen, Guohua; Zhang, Jing; Wang, Mengxing; Lei, Du; Yang, Guang; Zhang, Shanmin; Du, Xiaoxia

    2014-06-01

    Multivariate pattern classification analysis (MVPA) has been applied to functional magnetic resonance imaging (fMRI) data to decode brain states from spatially distributed activation patterns. Decoding upper limb movements from non-invasively recorded human brain activation is crucial for implementing a brain-machine interface that directly harnesses an individual's thoughts to control external devices or computers. The aim of this study was to decode the individual finger movements from fMRI single-trial data. Thirteen healthy human subjects participated in a visually cued delayed finger movement task, and only one slight button press was performed in each trial. Using MVPA, the decoding accuracy (DA) was computed separately for the different motor-related regions of interest. For the construction of feature vectors, the feature vectors from two successive volumes in the image series for a trial were concatenated. With these spatial-temporal feature vectors, we obtained a 63.1% average DA (84.7% for the best subject) for the contralateral primary somatosensory cortex and a 46.0% average DA (71.0% for the best subject) for the contralateral primary motor cortex; both of these values were significantly above the chance level (20%). In addition, we implemented searchlight MVPA to search for informative regions in an unbiased manner across the whole brain. Furthermore, by applying searchlight MVPA to each volume of a trial, we visually demonstrated the information for decoding, both spatially and temporally. The results suggest that the non-invasive fMRI technique may provide informative features for decoding individual finger movements and the potential of developing an fMRI-based brain-machine interface for finger movement. PMID:24661456

  4. Compensatory Versus Noncompensatory Shoulder Movements Used for Reaching in Stroke.

    PubMed

    Levin, Mindy F; Liebermann, Dario G; Parmet, Yisrael; Berman, Sigal

    2016-08-01

    Background The extent to which the upper-limb flexor synergy constrains or compensates for arm motor impairment during reaching is controversial. This synergy can be quantified with a minimal marker set describing movements of the arm-plane. Objectives To determine whether and how (a) upper-limb flexor synergy in patients with chronic stroke contributes to reaching movements to different arm workspace locations and (b) reaching deficits can be characterized by arm-plane motion. Methods Sixteen post-stroke and 8 healthy control subjects made unrestrained reaching movements to targets located in ipsilateral, central, and contralateral arm workspaces. Arm-plane, arm, and trunk motion, and their temporal and spatial linkages were analyzed. Results Individuals with moderate/severe stroke used greater arm-plane movement and compensatory trunk movement compared to those with mild stroke and control subjects. Arm-plane and trunk movements were more temporally coupled in stroke compared with controls. Reaching accuracy was related to different segment and joint combinations for each target and group: arm-plane movement in controls and mild stroke subjects, and trunk and elbow movements in moderate/severe stroke subjects. Arm-plane movement increased with time since stroke and when combined with trunk rotation, discriminated between different subject groups for reaching the central and contralateral targets. Trunk movement and arm-plane angle during target reaches predicted the subject group. Conclusions The upper-limb flexor synergy was used adaptively for reaching accuracy by patients with mild, but not moderate/severe stroke. The flexor synergy, as parameterized by the amount of arm-plane motion, can be used by clinicians to identify levels of motor recovery in patients with stroke. PMID:26510934

  5. Spinal Motion and Muscle Activity during Active Trunk Movements – Comparing Sheep and Humans Adopting Upright and Quadrupedal Postures

    PubMed Central

    Valentin, Stephanie; Licka, Theresia F.

    2016-01-01

    Sheep are used as models for the human spine, yet comparative in vivo data necessary for validation is limited. The purpose of this study was therefore to compare spinal motion and trunk muscle activity during active trunk movements in sheep and humans. Three-dimensional kinematic data as well as surface electromyography (sEMG) of spinal flexion and extension was compared in twenty-four humans in upright (UR) and 4-point kneeling (KN) postures and in 17 Austrian mountain sheep. Kinematic markers were attached over the sacrum, posterior iliac spines, and spinous and transverse processes of T5, T8, T11, L2 and L5 in humans and over the sacrum, tuber sacrale, T5, T8, T12, L3 and L7 in sheep. The activity of erector spinae (ES), rectus abdominis (RA), obliquus externus (OE), and obliquus internus (OI) were collected. Maximum sEMG (MOE) was identified for each muscle and trial, and reported as a percentage (MOE%) of the overall maximally observed sEMG from all trials. Spinal range of motion was significantly smaller in sheep compared to humans (UR / KN) during flexion (sheep: 6–11°; humans 12–34°) and extension (sheep: 4°; humans: 11–17°). During extension, MOE% of ES was greater in sheep (median: 77.37%) than UR humans (24.89%), and MOE% of OE and OI was greater in sheep (OE 76.20%; OI 67.31%) than KN humans (OE 21.45%; OI 19.34%), while MOE% of RA was lower in sheep (21.71%) than UR humans (82.69%). During flexion, MOE% of RA was greater in sheep (83.09%) than humans (KN 47.42%; UR 41.38%), and MOE% of ES in sheep (45.73%) was greater than KN humans (14.45%), but smaller than UR humans (72.36%). The differences in human and sheep spinal motion and muscle activity suggest that caution is warranted when ovine data are used to infer human spine biomechanics. PMID:26741136

  6. Continuous neuronal ensemble control of simulated arm reaching by a human with tetraplegia

    NASA Astrophysics Data System (ADS)

    Chadwick, E. K.; Blana, D.; Simeral, J. D.; Lambrecht, J.; Kim, S. P.; Cornwell, A. S.; Taylor, D. M.; Hochberg, L. R.; Donoghue, J. P.; Kirsch, R. F.

    2011-06-01

    Functional electrical stimulation (FES), the coordinated electrical activation of multiple muscles, has been used to restore arm and hand function in people with paralysis. User interfaces for such systems typically derive commands from mechanically unrelated parts of the body with retained volitional control, and are unnatural and unable to simultaneously command the various joints of the arm. Neural interface systems, based on spiking intracortical signals recorded from the arm area of motor cortex, have shown the ability to control computer cursors, robotic arms and individual muscles in intact non-human primates. Such neural interface systems may thus offer a more natural source of commands for restoring dexterous movements via FES. However, the ability to use decoded neural signals to control the complex mechanical dynamics of a reanimated human limb, rather than the kinematics of a computer mouse, has not been demonstrated. This study demonstrates the ability of an individual with long-standing tetraplegia to use cortical neuron recordings to command the real-time movements of a simulated dynamic arm. This virtual arm replicates the dynamics associated with arm mass and muscle contractile properties, as well as those of an FES feedback controller that converts user commands into the required muscle activation patterns. An individual with long-standing tetraplegia was thus able to control a virtual, two-joint, dynamic arm in real time using commands derived from an existing human intracortical interface technology. These results show the feasibility of combining such an intracortical interface with existing FES systems to provide a high-performance, natural system for restoring arm and hand function in individuals with extensive paralysis. This paper was originally submitted for the special issue containing contributions from the Fourth International Brain-Computer Interface Meeting.

  7. Common neural correlates of real and imagined movements contributing to the performance of brain–machine interfaces

    PubMed Central

    Sugata, Hisato; Hirata, Masayuki; Yanagisawa, Takufumi; Matsushita, Kojiro; Yorifuji, Shiro; Yoshimine, Toshiki

    2016-01-01

    The relationship between M1 activity representing motor information in real and imagined movements have not been investigated with high spatiotemporal resolution using non-invasive measurements. We examined the similarities and differences in M1 activity during real and imagined movements. Ten subjects performed or imagined three types of right upper limb movements. To infer the movement type, we used 40 virtual channels in the M1 contralateral to the movement side (cM1) using a beamforming approach. For both real and imagined movements, cM1 activities increased around response onset, after which their intensities were significantly different. Similarly, although decoding accuracies surpassed the chance level in both real and imagined movements, these were significantly different after the onset. Single virtual channel-based analysis showed that decoding accuracy significantly increased around the hand and arm areas during real and imagined movements and that these are spatially correlated. The temporal correlation of decoding accuracy significantly increased around the hand and arm areas, except for the period immediately after response onset. Our results suggest that cM1 is involved in similar neural activities related to the representation of motor information during real and imagined movements, except for presence or absence of sensory–motor integration induced by sensory feedback. PMID:27090735

  8. Long-range movement of humpback whales and their overlap with anthropogenic activity in the South Atlantic Ocean.

    PubMed

    Rosenbaum, Howard C; Maxwell, Sara M; Kershaw, Francine; Mate, Bruce

    2014-04-01

    Humpback whales (Megaptera novaeangliae) are managed by the International Whaling Commission as 7 primary populations that breed in the tropics and migrate to 6 feeding areas around the Antarctic. There is little information on individual movements within breeding areas or migratory connections to feeding grounds. We sought to better understand humpback whale habitat use and movements at breeding areas off West Africa, and during the annual migration to Antarctic feeding areas. We also assessed potential overlap between whale habitat and anthropogenic activities. We used Argos satellite-monitored radio tags to collect data on 13 animals off Gabon, a primary humpback whale breeding area. We quantified habitat use for 3 cohorts of whales and used a state-space model to determine transitions in the movement behavior of individuals. We developed a spatial metric of overlap between whale habitat and models of cumulative human activities, including oil platforms, toxicants, and shipping. We detected strong heterogeneity in movement behavior over time that is consistent with previous genetic evidence of multiple populations in the region. Breeding areas for humpback whales in the eastern Atlantic were extensive and extended north of Gabon late in the breeding season. We also observed, for the first time, direct migration between West Africa and sub-Antarctic feeding areas. Potential overlap of whale habitat with human activities was the highest in exclusive economic zones close to shore, particularly in areas used by both individual whales and the hydrocarbon industry. Whales potentially overlapped with different activities during each stage of their migration, which makes it difficult to implement mitigation measures over their entire range. Our results and existing population-level data may inform delimitation of populations and actions to mitigate potential threats to whales as part of local, regional, and international management of highly migratory marine species

  9. Learning Dictionaries of Sparse Codes of 3D Movements of Body Joints for Real-Time Human Activity Understanding

    PubMed Central

    Qi, Jin; Yang, Zhiyong

    2014-01-01

    Real-time human activity recognition is essential for human-robot interactions for assisted healthy independent living. Most previous work in this area is performed on traditional two-dimensional (2D) videos and both global and local methods have been used. Since 2D videos are sensitive to changes of lighting condition, view angle, and scale, researchers begun to explore applications of 3D information in human activity understanding in recently years. Unfortunately, features that work well on 2D videos usually don't perform well on 3D videos and there is no consensus on what 3D features should be used. Here we propose a model of human activity recognition based on 3D movements of body joints. Our method has three steps, learning dictionaries of sparse codes of 3D movements of joints, sparse coding, and classification. In the first step, space-time volumes of 3D movements of body joints are obtained via dense sampling and independent component analysis is then performed to construct a dictionary of sparse codes for each activity. In the second step, the space-time volumes are projected to the dictionaries and a set of sparse histograms of the projection coefficients are constructed as feature representations of the activities. Finally, the sparse histograms are used as inputs to a support vector machine to recognize human activities. We tested this model on three databases of human activities and found that it outperforms the state-of-the-art algorithms. Thus, this model can be used for real-time human activity recognition in many applications. PMID:25473850

  10. Learning dictionaries of sparse codes of 3D movements of body joints for real-time human activity understanding.

    PubMed

    Qi, Jin; Yang, Zhiyong

    2014-01-01

    Real-time human activity recognition is essential for human-robot interactions for assisted healthy independent living. Most previous work in this area is performed on traditional two-dimensional (2D) videos and both global and local methods have been used. Since 2D videos are sensitive to changes of lighting condition, view angle, and scale, researchers begun to explore applications of 3D information in human activity understanding in recently years. Unfortunately, features that work well on 2D videos usually don't perform well on 3D videos and there is no consensus on what 3D features should be used. Here we propose a model of human activity recognition based on 3D movements of body joints. Our method has three steps, learning dictionaries of sparse codes of 3D movements of joints, sparse coding, and classification. In the first step, space-time volumes of 3D movements of body joints are obtained via dense sampling and independent component analysis is then performed to construct a dictionary of sparse codes for each activity. In the second step, the space-time volumes are projected to the dictionaries and a set of sparse histograms of the projection coefficients are constructed as feature representations of the activities. Finally, the sparse histograms are used as inputs to a support vector machine to recognize human activities. We tested this model on three databases of human activities and found that it outperforms the state-of-the-art algorithms. Thus, this model can be used for real-time human activity recognition in many applications. PMID:25473850

  11. Is Two Better than One? Limb Activation Treatment Combined with Contralesional Arm Vibration to Ameliorate Signs of Left Neglect

    PubMed Central

    Pitteri, Marco; Arcara, Giorgio; Passarini, Laura; Meneghello, Francesca; Priftis, Konstantinos

    2013-01-01

    In the present study, we evaluated the effects of the Limb Activation Treatment (LAT) alone and in combination with the Contralateral Arm Vibration (CAV) on left neglect (LN) rehabilitation. We conceived them as techniques that both prompt the activation of the lesioned right hemisphere because of the activation (with the LAT as an active technique) and the stimulation (with the CAV as a passive technique) of the left hemibody. To test the effect of the simultaneous use of these two techniques (i.e., LAT and CAV) on visuo-spatial aspects of LN, we described the case of an LN patient (GR), who showed high intra-individual variability (IIV) in performance. Given the high IIV of GR, we used an ABAB repeated-measures design to better define the effectiveness of the combined application of LAT and CAV, as a function of time. The results showed an improvement of GR’s performance on the Bells test following the combined application of LAT and CAV, with respect to the application of LAT alone. We did not find, however, significant effects of treatment on two other LN tests (i.e., Line bisection and Picture scanning). We propose that the combined application of LAT and CAV can be beneficial for some aspects of LN. PMID:23966926

  12. Eye-Movement Analysis of Students' Active Examination Strategy and Its Transfer in Visuospatial Representations

    ERIC Educational Resources Information Center

    Kim, Kinam; Kim, Minsung; Shin, Jungyeop; Ryu, Jaemyong

    2015-01-01

    This article examined the role of task demand and its effects on transfer in geographic learning. Student performance was measured through eye-movement analysis in two related experiments. In Experiment 1, the participants were told that they would travel through an area depicted in photographs either driving an automobile or observing the…

  13. Using Constraints to Design Developmentally Appropriate Movement Activities for Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Pope, Michelle; Breslin, Casey M.; Getchell, Nancy; Liu, Ting

    2012-01-01

    Some of the characteristics and behaviors of children with autism spectrum disorder (ASD), such as difficulty with social interactions and sensory integration, make physical education instruction difficult. Children with ASD also encounter movement difficulties, such as motor-planning and anticipatory deficits. One way to enhance the ability of…

  14. "But Aren't Cults Bad?": Active Learning, Productive Chaos, and Teaching New Religious Movements

    ERIC Educational Resources Information Center

    Zeller, Benjamin E.

    2015-01-01

    This article considers the challenges inherent when teaching about new religious movements ("cults"), how successful instructors have surmounted them, and how teacher-scholars in other fields of religious studies can benefit from a discussion of the successful teaching of new religions. I note that student-centered pedagogies are crucial…

  15. Sequential control signals determine arm and trunk contributions to hand transport during reaching in humans.

    PubMed

    Rossi, Elena; Mitnitski, Arnold; Feldman, Anatol G

    2002-01-15

    When reaching towards objects placed outside the arm workspace, the trunk assumes an active role in transport of the hand by contributing to the extent of movement while simultaneously maintaining the direction of reach. We investigated the spatial-temporal aspects of the integration of the trunk motion into reaching. Specifically, we tested the hypothesis that the efficiency ('gain') of the arm-trunk co-ordination determining the contribution of the trunk to the extent of hand movement may vary substantially with the phase of reaching. Sitting subjects made fast pointing movements towards ipsi- and a contralateral targets placed beyond the reach of the right arm so that a forward trunk motion was required to assist in transporting the hand to the target. Sight of the arm and target was blocked before the movement onset. In randomly selected trials, the trunk motion was unexpectedly prevented by an electromagnet. Subjects were instructed to make stereotypical movements whether or not the trunk was arrested. In non-perturbed trials, most subjects began to move the hand and trunk simultaneously. In trunk-blocked trials, it was impossible for the hand to cover the whole pointing distance but the hand trajectory and velocity profile initially matched those from the trials in which the trunk motion was free, approximately until the hand reached its peak velocity. The arm inter-joint co-ordination substantially changed in response to the trunk arrest at a minimal latency of 40 ms after the perturbation onset. The results suggest that when the trunk was free, the influence of the trunk motion on the hand trajectory and velocity profile was initially neutralized by appropriate changes in the arm joint angles. Only after the hand had reached its peak velocity did the trunk contribute to the extent of pointing. Previous studies suggested that the central commands underlying the transport component of arm movements are completed when the hand reaches peak velocity. These

  16. Recommendations for Standardizing Validation Procedures Assessing Physical Activity of Older Persons by Monitoring Body Postures and Movements

    PubMed Central

    Lindemann, Ulrich; Zijlstra, Wiebren; Aminian, Kamiar; Chastin, Sebastien F.M.; de Bruin, Eling D.; Helbostad, Jorunn L.; Bussmann, Johannes B.J.

    2014-01-01

    Physical activity is an important determinant of health and well-being in older persons and contributes to their social participation and quality of life. Hence, assessment tools are needed to study this physical activity in free-living conditions. Wearable motion sensing technology is used to assess physical activity. However, there is a lack of harmonisation of validation protocols and applied statistics, which make it hard to compare available and future studies. Therefore, the aim of this paper is to formulate recommendations for assessing the validity of sensor-based activity monitoring in older persons with focus on the measurement of body postures and movements. Validation studies of body-worn devices providing parameters on body postures and movements were identified and summarized and an extensive inter-active process between authors resulted in recommendations about: information on the assessed persons, the technical system, and the analysis of relevant parameters of physical activity, based on a standardized and semi-structured protocol. The recommended protocols can be regarded as a first attempt to standardize validity studies in the area of monitoring physical activity. PMID:24434881

  17. Effects of task-oriented robot training on arm function, activity, and quality of life in chronic stroke patients: a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Over fifty percent of stroke patients experience chronic arm hand performance problems, compromising independence in daily life activities and quality of life. Task-oriented training may improve arm hand performance after stroke, whereby augmented therapy may lead to a better treatment outcome. Technology-supported training holds opportunities for increasing training intensity. However, the effects of robot-supported task-oriented training with real life objects in stroke patients are not known to date. The aim of the present study was to investigate the effectiveness and added value of the Haptic Master robot combined with task-oriented arm hand training in chronic stroke patients. Methods In a single-blind randomized controlled trial, 22 chronic stroke patients were randomly allocated to receive either task-oriented robot-assisted arm-hand training (experimental group) or task-oriented non-robotic arm-hand training (control group). For training, the T-TOAT (Technology-supported Task-Oriented Arm Training) method was applied. Training was provided during 8 weeks, 4 times/week, 2× 30 min/day. Results A significant improvement after training on the Action Research Arm Test (ARAT) was demonstrated in the experimental group (p = 0.008). Results were maintained until 6 months after cessation of the training. On the perceived performance measure (Motor Activity Log (MAL)), both, the experimental and control group improved significantly after training (control group p = 0.008; experimental group p = 0.013). The improvements on MAL in both groups were maintained until 6 months after cessation of the training. With regard to quality of life, only in the control group a significant improvement after training was found (EuroQol-5D p = 0.015, SF-36 physical p = 0.01). However, the improvement on SF-36 in the control group was not maintained (p = 0.012). No between-group differences could be demonstrated on any of the outcome measures

  18. Supplemental Feeding for Ecotourism Reverses Diel Activity and Alters Movement Patterns and Spatial Distribution of the Southern Stingray, Dasyatis americana

    PubMed Central

    Corcoran, Mark J.; Wetherbee, Bradley M.; Shivji, Mahmood S.; Potenski, Matthew D.; Chapman, Demian D.; Harvey, Guy M.

    2013-01-01

    Southern stingrays, Dasyatis americana, have been provided supplemental food in ecotourism operations at Stingray City Sandbar (SCS), Grand Cayman since 1986, with this site becoming one of the world’s most famous and heavily visited marine wildlife interaction venues. Given expansion of marine wildlife interactive tourism worldwide, there are questions about the effects of such activities on the focal species and their ecosystems. We used a combination of acoustic telemetry and tag-recapture efforts to test the hypothesis that human-sourced supplemental feeding has altered stingray activity patterns and habitat use at SCS relative to wild animals at control sites. Secondarily, we also qualitatively estimated the population size of stingrays supporting this major ecotourism venue. Tag-recapture data indicated that a population of at least 164 stingrays, over 80% female, utilized the small area at SCS for prolonged periods of time. Examination of comparative movements of mature female stingrays at SCS and control sites revealed strong differences between the two groups: The fed animals demonstrated a notable inversion of diel activity, being constantly active during the day with little movement at night compared to the nocturnally active wild stingrays; The fed stingrays utilized significantly (p<0.05) smaller 24 hour activity spaces compared to wild conspecifics, staying in close proximity to the ecotourism site; Fed stingrays showed a high degree of overlap in their core activity spaces compared to wild stingrays which were largely solitary in the spaces utilized (72% vs. 3% overlap respectively). Supplemental feeding has strikingly altered movement behavior and spatial distribution of the stingrays, and generated an atypically high density of animals at SCS which could have downstream fitness costs for individuals and potentially broader ecosystem effects. These findings should help environmental managers plan mitigating measures for existing operations, and

  19. Supplemental feeding for ecotourism reverses diel activity and alters movement patterns and spatial distribution of the southern stingray, Dasyatis americana.

    PubMed

    Corcoran, Mark J; Wetherbee, Bradley M; Shivji, Mahmood S; Potenski, Matthew D; Chapman, Demian D; Harvey, Guy M

    2013-01-01

    Southern stingrays, Dasyatis americana, have been provided supplemental food in ecotourism operations at Stingray City Sandbar (SCS), Grand Cayman sin