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Sample records for proprioceptive deafferentation slows

  1. A neuroplastic deafferentation hypothesis for bipolar disorder

    PubMed Central

    Rogers, Jonathan; Mirams, Jamie; Patel, Rashmi

    2015-01-01

    Bipolar disorder, characterised by extreme cyclical variations in mood between depression and mania, is a common, debilitating and sometimes fatal psychiatric condition with an unclear aetiology. In this paper we propose a hypothesis for the development of bipolar disorder through which neuroplastic changes in response to an index depressive episode leads to the amplification of subthreshold pleasurable stimuli that then drive conversion into a manic state. This ‘pleasure deafferentation hypothesis’ is reached through a discussion of the neuroscientific basis of deafferentation at the level of the neuron and its role in the development of various neurological and psychiatric phenomena before a case for deafferentation as applied to bipolar disorder is justified and its implications discussed. PMID:26459976

  2. Role of proprioception and vision in handwriting.

    PubMed

    Hepp-Reymond, Marie-Claude; Chakarov, Vihren; Schulte-Mönting, Jürgen; Huethe, Frank; Kristeva, Rumyana

    2009-08-14

    The objective of this study is to better understand the role of proprioception in handwriting and test earlier conclusions stating that the automated shaping of letters was not impaired by the removal of visual control in deafferentation. To this aim we compared the performance of the deafferented patient GL, who suffers from a complete loss of cutaneous and proprioceptive sensation, with that of eight healthy age- and sex-matched subjects. The word "Parallele", written within a short sentence with and without visual control, was quantified using a digital writing tablet. Three of the 13 analyzed parameters were strikingly different in patient GL compared to healthy subjects, both with and without vision: increase of number of pen touches, increase in number of inversions in velocity, and decrease of mean stroke frequency. The changes in these three parameters indicate a strong impairment in automated behaviour in the absence of proprioception and touch. This impairment is also supported by the significantly longer movement duration, which is also significantly increased by the removal of visual control. The present study provides for the first time a quantification of handwriting in a completely deafferented patient and reveals the central role of proprioception for the storage, updating, and maintenance of skilled motor programs. The fact that the deficits are already present with visual feedback suggests that the role of vision in handwriting is only secondary.

  3. Role of proprioception and vision in handwriting.

    PubMed

    Hepp-Reymond, Marie-Claude; Chakarov, Vihren; Schulte-Mönting, Jürgen; Huethe, Frank; Kristeva, Rumyana

    2009-08-14

    The objective of this study is to better understand the role of proprioception in handwriting and test earlier conclusions stating that the automated shaping of letters was not impaired by the removal of visual control in deafferentation. To this aim we compared the performance of the deafferented patient GL, who suffers from a complete loss of cutaneous and proprioceptive sensation, with that of eight healthy age- and sex-matched subjects. The word "Parallele", written within a short sentence with and without visual control, was quantified using a digital writing tablet. Three of the 13 analyzed parameters were strikingly different in patient GL compared to healthy subjects, both with and without vision: increase of number of pen touches, increase in number of inversions in velocity, and decrease of mean stroke frequency. The changes in these three parameters indicate a strong impairment in automated behaviour in the absence of proprioception and touch. This impairment is also supported by the significantly longer movement duration, which is also significantly increased by the removal of visual control. The present study provides for the first time a quantification of handwriting in a completely deafferented patient and reveals the central role of proprioception for the storage, updating, and maintenance of skilled motor programs. The fact that the deficits are already present with visual feedback suggests that the role of vision in handwriting is only secondary. PMID:19463909

  4. Proprioception Is Necessary for Body Schema Plasticity: Evidence from a Deafferented Patient

    PubMed Central

    Cardinali, Lucilla; Brozzoli, Claudio; Luauté, Jacques; Roy, Alice C.; Farnè, Alessandro

    2016-01-01

    The ability of using a large variety of tools is important in our daily life. Behind human tool-use abilities lays the brain capacity to incorporate tools into the body representation for action (Body Schema, BS), thought to rely mainly on proprioceptive information. Here, we tested whether tool incorporation is possible in absence of proprioception by studying a patient with right upper-limb deafferentation. We adopted a paradigm sensitive to changes of the BS and analyzed the kinematics of free-hand movements before and after tool-use, in three sessions over a period of 2 years. In the first session, before tool-use, the kinematics of the deafferented hand was disrupted. Similarly, the first movements with the tool (a mechanical grabber elongating the arm by ~40 cm) showed an abnormal profile that tended to normalize at the end of the session. Subsequent free-hand movements were also normalized. At session 2, 6 months later, the patient exhibited normal free-hand kinematic profiles, additionally showing changes in grasping kinematics after tool-use, but no sign of tool incorporation. A follow-up 2 years later, further confirmed the normalized kinematic profile but the absence of tool incorporation. This first description of tool-use in absence of proprioception shows the fundamental role of proprioception in the update of the BS. These results provide an important further step in understanding human motor control and have implications for future development of rehabilitation programs for patients with sensory deficits. PMID:27378879

  5. Proprioception Is Necessary for Body Schema Plasticity: Evidence from a Deafferented Patient.

    PubMed

    Cardinali, Lucilla; Brozzoli, Claudio; Luauté, Jacques; Roy, Alice C; Farnè, Alessandro

    2016-01-01

    The ability of using a large variety of tools is important in our daily life. Behind human tool-use abilities lays the brain capacity to incorporate tools into the body representation for action (Body Schema, BS), thought to rely mainly on proprioceptive information. Here, we tested whether tool incorporation is possible in absence of proprioception by studying a patient with right upper-limb deafferentation. We adopted a paradigm sensitive to changes of the BS and analyzed the kinematics of free-hand movements before and after tool-use, in three sessions over a period of 2 years. In the first session, before tool-use, the kinematics of the deafferented hand was disrupted. Similarly, the first movements with the tool (a mechanical grabber elongating the arm by ~40 cm) showed an abnormal profile that tended to normalize at the end of the session. Subsequent free-hand movements were also normalized. At session 2, 6 months later, the patient exhibited normal free-hand kinematic profiles, additionally showing changes in grasping kinematics after tool-use, but no sign of tool incorporation. A follow-up 2 years later, further confirmed the normalized kinematic profile but the absence of tool incorporation. This first description of tool-use in absence of proprioception shows the fundamental role of proprioception in the update of the BS. These results provide an important further step in understanding human motor control and have implications for future development of rehabilitation programs for patients with sensory deficits.

  6. Proprioception Is Necessary for Body Schema Plasticity: Evidence from a Deafferented Patient.

    PubMed

    Cardinali, Lucilla; Brozzoli, Claudio; Luauté, Jacques; Roy, Alice C; Farnè, Alessandro

    2016-01-01

    The ability of using a large variety of tools is important in our daily life. Behind human tool-use abilities lays the brain capacity to incorporate tools into the body representation for action (Body Schema, BS), thought to rely mainly on proprioceptive information. Here, we tested whether tool incorporation is possible in absence of proprioception by studying a patient with right upper-limb deafferentation. We adopted a paradigm sensitive to changes of the BS and analyzed the kinematics of free-hand movements before and after tool-use, in three sessions over a period of 2 years. In the first session, before tool-use, the kinematics of the deafferented hand was disrupted. Similarly, the first movements with the tool (a mechanical grabber elongating the arm by ~40 cm) showed an abnormal profile that tended to normalize at the end of the session. Subsequent free-hand movements were also normalized. At session 2, 6 months later, the patient exhibited normal free-hand kinematic profiles, additionally showing changes in grasping kinematics after tool-use, but no sign of tool incorporation. A follow-up 2 years later, further confirmed the normalized kinematic profile but the absence of tool incorporation. This first description of tool-use in absence of proprioception shows the fundamental role of proprioception in the update of the BS. These results provide an important further step in understanding human motor control and have implications for future development of rehabilitation programs for patients with sensory deficits. PMID:27378879

  7. Body inversion effect without body sense: insights from deafferentation.

    PubMed

    Bosbach, Simone; Knoblich, Guenther; Reed, Catherine L; Cole, Jonathan; Prinz, Wolfgang

    2006-01-01

    Like faces, human bodies are recognized via the configuration of their parts; their recognition is impaired by inversion. Processing of configural relations has been shown to depend on perceptual expertise with certain classes of objects. Because people see their own body and others' bodies frequently, humans are experts in the visual processing of human body postures. In addition, the observer's own on-line, multimodal body representation which heavily relies on current proprioception may play a crucial role in recognizing human body postures. We investigated whether static body posture recognition relied on current proprioceptive inputs or whether visual familiarity and stored body representations were sufficient. IW, who is deafferented (lost cutaneous touch and proprioception from his body), was tested on the recognition of upright and inverted human body postures, faces, and houses. As controls, IW showed an inversion effect for abstract, common, and rare human body postures as well as faces, but not houses. Results rule out a strong contribution of current afferent inputs to the recognition of human postures. The findings are discussed in terms of the role of the body schema in body posture recognition and how other contributions from one's own body may be involved in the visual processing of human bodies.

  8. Patterns of olfactory bulb neurogenesis in the adult zebrafish are altered following reversible deafferentation.

    PubMed

    Trimpe, Darcy M; Byrd-Jacobs, Christine A

    2016-09-01

    Adult brain plasticity can be investigated using reversible methods that remove afferent innervation but allow return of sensory input. Repeated intranasal irrigation with Triton X-100 in adult zebrafish diminishes innervation to the olfactory bulb, resulting in a number of alterations in bulb structure and function, and cessation of the treatment allows for reinnervation and recovery. Using bromodeoxyuridine, Hu, and caspase-3 immunoreactivity we examined cell proliferation, differentiation, migration, and survival under conditions of acute and chronic deafferentation and reafferentation. Cell proliferation within the olfactory bulb was not influenced by acute or chronic deafferentation or reafferentation, but cell fate (including differentiation, migration, and/or survival of newly formed cells) was affected. We found that chronic deafferentation caused a bilateral increase in the number of newly formed cells that migrated into the bulb, although the amount of cell death of these new cells was significantly increased compared to untreated fish. Reafferentation also increased the number of newly formed cells migrating into both bulbs, suggesting that the deafferentation effect on cell fate was maintained. Reafferentation resulted in a decrease in newly formed cells that became neurons and, although death of newly formed cells was not altered from control levels, survival was reduced in relation to that seen in chronically deafferented fish. The potential effect of age on cell genesis was also examined. While the amount of cell migration into the olfactory bulbs was not affected by fish age, more of the newly formed cells became neurons in older fish. Younger fish displayed more cell death under conditions of chronic deafferentation. In sum, our results show that reversible deafferentation affects several aspects of cell fate, including cell differentiation, migration, and survival, and age of the fish influences the response to deafferentation. PMID:27343831

  9. Gray-matter atrophy after chronic complete unilateral vestibular deafferentation.

    PubMed

    Hüfner, Katharina; Stephan, Thomas; Hamilton, Derek A; Kalla, Roger; Glasauer, Stefan; Strupp, Michael; Brandt, Thomas

    2009-05-01

    It has been shown in blind patients that the abolition of sensory input can lead to changes in white- and cortical gray-matter volumes. Here the white- and gray-matter changes found with whole brain voxel-based morphometry in 16 patients with complete chronic unilateral vestibular deafferentation (UVD) due to vestibular schwannoma removal several years prior are reported on. Subtle deficits in spatial memory and navigation were previously shown in patients with right UVD. Images of the brains of right-UVD patients were flipped, standard preprocessing steps were performed, and the data were modulated. Patients showed a gray-matter volume reduction in the cerebellum due to schwannoma removal, in the supramarginal gyrus ipsilateral to the lesion, as well as in the postcentral and superior temporal gyrus, areas involved in the vestibular cortical network, and in the motion-sensitive area MT/V5. There was no correlation with behavioral navigational abilities. No gray-matter atrophy was found in the insular cortical vestibular region or the hippocampus, both of which receive bilateral vestibular projections. The thalamus and tegmentum of the mesencephalon showed gray-matter reduction on the opposite side; this was possibly due to reduced auditory input, which is known to cross at this level. In comparison to healthy controls, no regional increases in gray-matter volume were seen. No white-matter changes were detected at the selected threshold.

  10. Proprioceptive contribution to distance estimation by motion parallax in a praying mantid

    PubMed

    Pabst; Kral

    1998-05-01

    The behavioural experiments described here examined, in the praying mantis Tenodera sinensis, the manner in which the proprioceptive cervical hair plate sensilla are involved in the measurement of the distance to a jump target with the aid of motion parallax actively produced by translatory head motion. Various combinations of surgical deafferentation of the cervical hair plate sensilla had no influence on the linearisation of head motion. However, the measurement of relative and absolute distance and the jump frequency were impaired by these interventions. From the results, it is concluded that the cervical hair plate sensilla are involved in the distance measurement mechanism, probably by allowing the nervous system to compare retinal image motion with head motion.

    PMID:9547327

  11. Electrical Vestibular Stimulation after Vestibular Deafferentation and in Vestibular Schwannoma

    PubMed Central

    Aw, Swee Tin; Todd, Michael John; Lehnen, Nadine; Aw, Grace Elizabeth; Weber, Konrad Peter; Eggert, Thomas; Halmagyi, Gabor Michael

    2013-01-01

    Background Vestibular reflexes, evoked by human electrical (galvanic) vestibular stimulation (EVS), are utilized to assess vestibular function and investigate its pathways. Our study aimed to investigate the electrically-evoked vestibulo-ocular reflex (eVOR) output after bilateral and unilateral vestibular deafferentations to determine the characteristics for interpreting unilateral lesions such as vestibular schwannomas. Methods EVOR was recorded with dual-search coils as binocular three-dimensional eye movements evoked by bipolar 100 ms-step at EVS intensities of [0.9, 2.5, 5.0, 7.5, 10.0]mA and unipolar 100 ms-step at 5 mA EVS intensity. Five bilateral vestibular deafferented (BVD), 12 unilateral vestibular deafferented (UVD), four unilateral vestibular schwannoma (UVS) patients and 17 healthy subjects were tested with bipolar EVS, and five UVDs with unipolar EVS. Results After BVD, bipolar EVS elicited no eVOR. After UVD, bipolar EVS of one functioning ear elicited bidirectional, excitatory eVOR to cathodal EVS with 9 ms latency and inhibitory eVOR to anodal EVS, opposite in direction, at half the amplitude with 12 ms latency, exhibiting an excitatory-inhibitory asymmetry. The eVOR patterns from UVS were consistent with responses from UVD confirming the vestibular loss on the lesion side. Unexpectedly, unipolar EVS of the UVD ear, instead of absent response, evoked one-third the bipolar eVOR while unipolar EVS of the functioning ear evoked half the bipolar response. Conclusions The bidirectional eVOR evoked by bipolar EVS from UVD with an excitatory-inhibitory asymmetry and the 3 ms latency difference between normal and lesion side may be useful for detecting vestibular lesions such as UVS. We suggest that current spread could account for the small eVOR to 5 mA unipolar EVS of the UVD ear. PMID:24349188

  12. Shoulder proprioception in baseball pitchers.

    PubMed

    Safran, M R; Borsa, P A; Lephart, S M; Fu, F H; Warner, J J

    2001-01-01

    We examined proprioceptive differences between the dominant and nondominant shoulders of 21 collegiate baseball pitchers without a history of shoulder instability or surgery. A proprioceptive testing device was used to measure kinesthesia and joint position sense. Joint position sense was significantly (P =.05) more accurate in the nondominant shoulder than in the dominant shoulder when starting at 75% of maximal external rotation and moving into internal rotation. There were no significant differences for proprioception in the other measured positions or with kinesthesia testing. Six pitchers with recent shoulder pain had a significant (P =.04) kinesthetic deficit in the symptomatic dominant shoulder compared with the asymptomatic shoulder, as measured in neutral rotation moving into internal rotation. The net effect of training, exercise-induced laxity, and increased external rotation in baseball pitchers does not affect proprioception, although shoulder pain, possibly due to rotator cuff inflammation or tendinitis, is associated with reduced kinesthetic sensation.

  13. Bilateral consequences of chronic unilateral deafferentation in the auditory system of the cricket Gryllus bimaculatus.

    PubMed

    Horch, Hadley Wilson; Sheldon, Elizabeth; Cutting, Claire C; Williams, Claire R; Riker, Dana M; Peckler, Hannah R; Sangal, Rohit B

    2011-01-01

    The auditory system of the cricket has the unusual ability to respond to deafferentation by compensatory growth and synapse formation. Auditory interneurons such as ascending neuron 2 (AN-2) in the cricket Gryllus bimaculatus possess a dendritic arbor that normally grows up to, but not over, the midline of the prothoracic ganglion. After chronic deafferentation throughout larval development, however, the AN-2 dendritic arbor changes dramatically, and medial dendrites sprout across the midline where they form compensatory synapses with the auditory afferents from the contralateral ear. We quantified the extent of the effects of chronic, unilateral deafferentation by measuring several cellular parameters of 3 different neuronal components of the auditory system: the deafferented AN-2, the contralateral (or nondeafferented) AN-2 and the contralateral auditory afferents. Neuronal tracers and confocal microscopy were used to visualize neurons, and double-label experiments were performed to examine the cellular relationship between pairs of cells. Dendritic complexity was quantified using a modified Sholl analysis, and the length and volume of processes and presynaptic varicosities were assessed under control and deafferented conditions. Chronic deafferentation significantly influenced the morphology of all 3 neuronal components examined. The overall dendritic complexity of the deafferented AN-2 dendritic arbor was reduced, while both the contralateral AN-2 dendritic arbor and the remaining, intact, auditory afferents grew longer. We found no significant changes in the volume or density of varicosities after deafferentation. These complex cellular changes after deafferentation are interpreted in the light of the reported differential regulation of vesicle-associated membrane protein and semaphorin 2a.

  14. Proprioceptive information processing in schizophrenia.

    PubMed

    Arnfred, Sidse M H

    2012-03-01

    This doctoral thesis focuses on brain activity in response to proprioceptive stimulation in schizophrenia. The works encompass methodological developments substantiated by investigations of healthy volunteers and two clinical studies of schizophrenia spectrum patients. American psychiatrist Sandor Rado (1890-1972) suggested that one of two un-reducible deficits in schizophrenia was a disorder of proprioception. Exploration of proprioceptive information processing is possible through the measurement of evoked and event related potentials. Event related EEG can be analyzed as conventional time-series averages or as oscillatory averages transformed into the frequency domain. Gamma activity evoked by electricity or by another type of somatosensory stimulus has not been reported before in schizophrenia. Gamma activity is considered to be a manifestation of perceptual integration. A new load stimulus was constructed that stimulated the proprioceptive dimension of recognition of applied force. This load stimulus was tested both in simple and several types of more complex stimulus paradigms, with and without tasks, in total in 66 healthy volunteers. The evoked potential (EP) resulting from the load stimulus was named the proprioceptive EP. The later components of the proprioceptive EP (> 150 ms) were modulated similarly to previously reported electrical somatosensory EPs by repetition and cognitive task. The earlier activity was further investigated through decomposition of the time-frequency transformed data by a new non-negative matrix analysis, and previous research and visual inspection validated these results. Several time-frequency components emerged in the proprioceptive EP. The contra-lateral parietal gamma component (60-70 ms; 30-41 Hz) had not previously been described in the somatosensory modality without electrical stimulation. The parietal beta component (87-103 ms; 19-22 Hz) was increased when the proprioceptive stimulus appeared in a predictable sequence in

  15. Proprioceptive information processing in schizophrenia.

    PubMed

    Arnfred, Sidse M H

    2012-03-01

    This doctoral thesis focuses on brain activity in response to proprioceptive stimulation in schizophrenia. The works encompass methodological developments substantiated by investigations of healthy volunteers and two clinical studies of schizophrenia spectrum patients. American psychiatrist Sandor Rado (1890-1972) suggested that one of two un-reducible deficits in schizophrenia was a disorder of proprioception. Exploration of proprioceptive information processing is possible through the measurement of evoked and event related potentials. Event related EEG can be analyzed as conventional time-series averages or as oscillatory averages transformed into the frequency domain. Gamma activity evoked by electricity or by another type of somatosensory stimulus has not been reported before in schizophrenia. Gamma activity is considered to be a manifestation of perceptual integration. A new load stimulus was constructed that stimulated the proprioceptive dimension of recognition of applied force. This load stimulus was tested both in simple and several types of more complex stimulus paradigms, with and without tasks, in total in 66 healthy volunteers. The evoked potential (EP) resulting from the load stimulus was named the proprioceptive EP. The later components of the proprioceptive EP (> 150 ms) were modulated similarly to previously reported electrical somatosensory EPs by repetition and cognitive task. The earlier activity was further investigated through decomposition of the time-frequency transformed data by a new non-negative matrix analysis, and previous research and visual inspection validated these results. Several time-frequency components emerged in the proprioceptive EP. The contra-lateral parietal gamma component (60-70 ms; 30-41 Hz) had not previously been described in the somatosensory modality without electrical stimulation. The parietal beta component (87-103 ms; 19-22 Hz) was increased when the proprioceptive stimulus appeared in a predictable sequence in

  16. Proprioceptive Factors in Operative Timing.

    ERIC Educational Resources Information Center

    Ellis, M. J.

    Time estimation is improved when the interval is filled with a motor response, with the proprioceptive feedback (PFB) presumably acting as a mediator. Altering the resistive dynamics of a handle moved 60 centimeters to fill a two-second interval manipulated the PFB from the response. Spelling aloud 2-, 3-, and 4-letter words during the motor…

  17. Perception of stochastically undersampled sound waveforms: a model of auditory deafferentation

    PubMed Central

    Lopez-Poveda, Enrique A.; Barrios, Pablo

    2013-01-01

    Auditory deafferentation, or permanent loss of auditory nerve afferent terminals, occurs after noise overexposure and aging and may accompany many forms of hearing loss. It could cause significant auditory impairment but is undetected by regular clinical tests and so its effects on perception are poorly understood. Here, we hypothesize and test a neural mechanism by which deafferentation could deteriorate perception. The basic idea is that the spike train produced by each auditory afferent resembles a stochastically digitized version of the sound waveform and that the quality of the waveform representation in the whole nerve depends on the number of aggregated spike trains or auditory afferents. We reason that because spikes occur stochastically in time with a higher probability for high- than for low-intensity sounds, more afferents would be required for the nerve to faithfully encode high-frequency or low-intensity waveform features than low-frequency or high-intensity features. Deafferentation would thus degrade the encoding of these features. We further reason that due to the stochastic nature of nerve firing, the degradation would be greater in noise than in quiet. This hypothesis is tested using a vocoder. Sounds were filtered through ten adjacent frequency bands. For the signal in each band, multiple stochastically subsampled copies were obtained to roughly mimic different stochastic representations of that signal conveyed by different auditory afferents innervating a given cochlear region. These copies were then aggregated to obtain an acoustic stimulus. Tone detection and speech identification tests were performed by young, normal-hearing listeners using different numbers of stochastic samplers per frequency band in the vocoder. Results support the hypothesis that stochastic undersampling of the sound waveform, inspired by deafferentation, impairs speech perception in noise more than in quiet, consistent with auditory aging effects. PMID:23882176

  18. Effect of deafferentation of the rat tongue on plasma corticosterone, aldosterone, angiotensin and ACTH levels

    SciTech Connect

    Polyntsev, Yu.V.; Serova, O.N.

    1987-09-01

    The effect of deafferentation of the tongue on the plasma level of hormones involved in regulation of the sodium ion level -- aldosterone, corticosterone, ACTH, and angiotensin -- was studied. Plasma hormone levels were determined by radioimmunoassay. The results indicate the important role of orosensory and taste perception in the processes of regulation of the sodium balance in the body. The experiments in this study were conducted on rats.

  19. Stochastic undersampling steepens auditory threshold/duration functions: implications for understanding auditory deafferentation and aging

    PubMed Central

    Marmel, Frédéric; Rodríguez-Mendoza, Medardo A.; Lopez-Poveda, Enrique A.

    2015-01-01

    It has long been known that some listeners experience hearing difficulties out of proportion with their audiometric losses. Notably, some older adults as well as auditory neuropathy patients have temporal-processing and speech-in-noise intelligibility deficits not accountable for by elevated audiometric thresholds. The study of these hearing deficits has been revitalized by recent studies that show that auditory deafferentation comes with aging and can occur even in the absence of an audiometric loss. The present study builds on the stochastic undersampling principle proposed by Lopez-Poveda and Barrios (2013) to account for the perceptual effects of auditory deafferentation. Auditory threshold/duration functions were measured for broadband noises that were stochastically undersampled to various different degrees. Stimuli with and without undersampling were equated for overall energy in order to focus on the changes that undersampling elicited on the stimulus waveforms, and not on its effects on the overall stimulus energy. Stochastic undersampling impaired the detection of short sounds (<20 ms). The detection of long sounds (>50 ms) did not change or improved, depending on the degree of undersampling. The results for short sounds show that stochastic undersampling, and hence presumably deafferentation, can account for the steeper threshold/duration functions observed in auditory neuropathy patients and older adults with (near) normal audiometry. This suggests that deafferentation might be diagnosed using pure-tone audiometry with short tones. It further suggests that the auditory system of audiometrically normal older listeners might not be “slower than normal”, as is commonly thought, but simply less well afferented. Finally, the results for both short and long sounds support the probabilistic theories of detectability that challenge the idea that auditory threshold occurs by integration of sound energy over time. PMID:26029098

  20. Temporary deafferentation evoked by cutaneous anesthesia: behavioral and electrophysiological findings in healthy subjects.

    PubMed

    Sehle, Aida; Büsching, Imke; Vogt, Eva; Liepert, Joachim

    2016-05-01

    Motor function and motor excitability can be modulated by changes of somatosensory input. Here, we performed a randomized single-blind trial to investigate behavioral and neurophysiological changes during temporary deafferentation of left upper arm and forearm in 31 right-handed healthy adults. Lidocaine cream was used to anesthetize the skin from wrist to shoulder, sparing the hand. As control condition, on a different day, a neutral cream was applied to the same skin area. The sequence (first Lidocaine, then placebo or vice versa) was randomized. Behavioral measures included the Grating Orientation Task, the Von Frey hair testing and the Nine-hole-peg-test. Transcranial magnetic stimulation was used to investigate short-interval intracortical inhibition, stimulus response curves, motor evoked potential amplitudes during pre-innervation and the cortical silent period (CSP). Recordings were obtained from left first dorsal interosseous muscle and from left flexor carpi radialis muscle. During deafferentation, the threshold of touch measured at the forearm was significantly worse. Other behavioral treatment-related changes were not found. The CSP showed a significant interaction between treatment and time in first dorsal interosseous muscle. CSP duration was longer during Lidocaine application and shorter during placebo exposure. We conclude that, in healthy subjects, temporary cutaneous deafferentation of upper and lower arm may have minor effects on motor inhibition, but not on sensory or motor function for the adjacent non-anesthetized hand. PMID:26983925

  1. Do Adolescent Idiopathic Scoliosis (AIS) Neglect Proprioceptive Information in Sensory Integration of Postural Control?

    PubMed Central

    Assaiante, Christine; Mallau, Sophie; Jouve, Jean-Luc; Bollini, Gérard; Vaugoyeau, Marianne

    2012-01-01

    Introduction It has been reported that AIS rely much more on ankle proprioception to control the amplitude of the balance control commands as compared to age-matched healthy adolescents. Our hypothesis was that AIS do not neglect proprioceptive information to control posture probably because of their vestibular deficits. We investigated the proprioceptive contribution to postural control in AIS which expresses spinal deformity during a crucial transitional period of ontogenesis. Methods 10 adolescents with idiopathic scoliosis (AIS) with moderate spinal deformity (10° < Cobb Angle >35°) and 10 control adolescents (CA) had to maintain vertical stance while very slow oscillations in the frontal plane (below the detection threshold of the semicircular canal system) were applied to the support with the eyes open and closed. Postural orientation and segmental stabilisation were analysed at head, shoulder, trunk and pelvis levels. Results Scoliosis did not affect vertical orientation control and segmental stabilization strategies. Vision improves postural control in both CA and AIS, which seem more dependent on visual cues than adults. Conclusions AIS as CA were unable to control efficiently their postural orientation on the basis of the proprioceptive cues, the only sensory information available in the EC situation, whereas in the same condition healthy young adults present no difficulty to achieve the postural control. This suggests that AIS as CA transitory neglect proprioceptive information to control their posture. These results and previous studies suggest the existence of different afferent pathways for proprioceptive information subserving different parts in sensory integration of postural control. We conclude that the static proprioceptive system is not affected by the idiopathic scoliosis, while the dynamic proprioceptive system would be mainly affected. PMID:22815779

  2. Defining proprioceptive behaviors for autonomous mobile robots

    NASA Astrophysics Data System (ADS)

    Overholt, James L.; Hudas, Greg R.; Gerhart, Grant R.

    2002-07-01

    Proprioception is a sense of body position and movement that supports the control of many automatic motor functions such as posture and locomotion. This concept, normally relegated to the fields of neural physiology and kinesiology, is being utilized in the field of unmanned mobile robotics. This paper looks at developing proprioceptive behaviors for use in controlling an unmanned ground vehicle. First, we will discuss the field of behavioral control of mobile robots. Next, a discussion of proprioception and the development of proprioceptive sensors will be presented. We will then focus on the development of a unique neural-fuzzy architecture that will be used to incorporate the control behaviors coming directly from the proprioceptive sensors. Finally we will present a simulation experiment where a simple multi-sensor robot, utilizing both external and proprioceptive sensors, is presented with the task of navigating an unknown terrain to a known target position. Results of the mobile robot utilizing this unique fusion methodology will be discussed.

  3. Update on proprioception: considerations for dance education.

    PubMed

    Batson, Glenna

    2009-01-01

    Proprioception is a topic of interest within the larger scope of dance pedagogy, science, and rehabilitation. As the science of proprioception changes, approaches to proprioceptive training also change. Thus, proprioceptive training in dance medicine has expanded to include balance protocols. A key concept within these protocols for treatment of lower extremity injuries is perturbation. Perturbation training is designed to evoke focal neuromuscular control at injured joint sites, as well as more global postural responses for overall balance and coordination. This article provides an update on the science of proprioception within the framework of postural control and balance. Specific practices from rehabilitation that integrate balance exercises into proprioceptive training are considered. Further research is needed to test the efficacy and utility of these exercises within the context of the dance studio.

  4. Extending human proprioception to cyber-physical systems

    NASA Astrophysics Data System (ADS)

    Keller, Kevin; Robinson, Ethan; Dickstein, Leah; Hahn, Heidi A.; Cattaneo, Alessandro; Mascareñas, David

    2016-04-01

    Despite advances in computational cognition, there are many cyber-physical systems where human supervision and control is desirable. One pertinent example is the control of a robot arm, which can be found in both humanoid and commercial ground robots. Current control mechanisms require the user to look at several screens of varying perspective on the robot, then give commands through a joystick-like mechanism. This control paradigm fails to provide the human operator with an intuitive state feedback, resulting in awkward and slow behavior and underutilization of the robot's physical capabilities. To overcome this bottleneck, we introduce a new human-machine interface that extends the operator's proprioception by exploiting sensory substitution. Humans have a proprioceptive sense that provides us information on how our bodies are configured in space without having to directly observe our appendages. We constructed a wearable device with vibrating actuators on the forearm, where frequency of vibration corresponds to the spatial configuration of a robotic arm. The goal of this interface is to provide a means to communicate proprioceptive information to the teleoperator. Ultimately we will measure the change in performance (time taken to complete the task) achieved by the use of this interface.

  5. The Effects of Cryotherapy on Proprioception System

    PubMed Central

    Furmanek, Mariusz Paweł; Słomka, Kajetan; Juras, Grzegorz

    2014-01-01

    Proprioception plays an important role in the complex mechanism of joint control. Contemporary sport activities impose extremely high physical demands on athletes. Winter sports are played in areas with excessively low temperatures. Moreover, many athletes are subjected to treatments that involve local lowering of the body temperature before, during, and after physical activity. This work reviews the current knowledge regarding the influence of local cryotherapy on the proprioception system. The reviewed literature identified several tests that evaluate different aspects of proprioception. There is no universally agreed protocol, or clear set of criteria for test conditions. The outcomes of different tests and assessments of cryotherapy procedures using different cold modalities are poorly correlated. In general, the published results on the mechanism of cryotherapy effects on proprioception are not uniquely conclusive and are frequently contradictory. Additional high-quality research is required to explicitly answer the following questions: (1) whether local cryotherapy influences all aspects of proprioception; (2) whether the current methods of evaluation are adequate for the exploration of the relationship between cryotherapy and proprioception; and (3) whether the application of local cryotherapy is safe for athletes regarding proprioception. The review clearly showed that there is no comprehensive model relating cryotherapy and proprioception. PMID:25478573

  6. Eyelid Opening with Trigeminal Proprioceptive Activation Regulates a Brainstem Arousal Mechanism.

    PubMed

    Matsuo, Kiyoshi; Ban, Ryokuya; Hama, Yuki; Yuzuriha, Shunsuke

    2015-01-01

    Eyelid opening stretches mechanoreceptors in the supratarsal Müller muscle to activate the proprioceptive fiber supplied by the trigeminal mesencephalic nucleus. This proprioception induces reflex contractions of the slow-twitch fibers in the levator palpebrae superioris and frontalis muscles to sustain eyelid and eyebrow positions against gravity. The cell bodies of the trigeminal proprioceptive neurons in the mesencephalon potentially make gap-junctional connections with the locus coeruleus neurons. The locus coeruleus is implicated in arousal and autonomic function. Due to the relationship between arousal, ventromedial prefrontal cortex, and skin conductance, we assessed whether upgaze with trigeminal proprioceptive evocation activates sympathetically innervated sweat glands and the ventromedial prefrontal cortex. Specifically, we examined whether 60° upgaze induces palmar sweating and hemodynamic changes in the prefrontal cortex in 16 subjects. Sweating was monitored using a thumb-mounted perspiration meter, and prefrontal cortex activity was measured with 45-channel, functional near-infrared spectroscopy (fNIRS) and 2-channel NIRS at Fp1 and Fp2. In 16 subjects, palmar sweating was induced by upgaze and decreased in response to downgaze. Upgaze activated the ventromedial prefrontal cortex with an accumulation of integrated concentration changes in deoxyhemoglobin, oxyhemoglobin, and total hemoglobin levels in 12 subjects. Upgaze phasically and degree-dependently increased deoxyhemoglobin level at Fp1 and Fp2, whereas downgaze phasically decreased it in 16 subjects. Unilateral anesthetization of mechanoreceptors in the supratarsal Müller muscle used to significantly reduce trigeminal proprioceptive evocation ipsilaterally impaired the increased deoxyhemoglobin level by 60° upgaze at Fp1 or Fp2 in 6 subjects. We concluded that upgaze with strong trigeminal proprioceptive evocation was sufficient to phasically activate sympathetically innervated sweat glands

  7. Eyelid Opening with Trigeminal Proprioceptive Activation Regulates a Brainstem Arousal Mechanism.

    PubMed

    Matsuo, Kiyoshi; Ban, Ryokuya; Hama, Yuki; Yuzuriha, Shunsuke

    2015-01-01

    Eyelid opening stretches mechanoreceptors in the supratarsal Müller muscle to activate the proprioceptive fiber supplied by the trigeminal mesencephalic nucleus. This proprioception induces reflex contractions of the slow-twitch fibers in the levator palpebrae superioris and frontalis muscles to sustain eyelid and eyebrow positions against gravity. The cell bodies of the trigeminal proprioceptive neurons in the mesencephalon potentially make gap-junctional connections with the locus coeruleus neurons. The locus coeruleus is implicated in arousal and autonomic function. Due to the relationship between arousal, ventromedial prefrontal cortex, and skin conductance, we assessed whether upgaze with trigeminal proprioceptive evocation activates sympathetically innervated sweat glands and the ventromedial prefrontal cortex. Specifically, we examined whether 60° upgaze induces palmar sweating and hemodynamic changes in the prefrontal cortex in 16 subjects. Sweating was monitored using a thumb-mounted perspiration meter, and prefrontal cortex activity was measured with 45-channel, functional near-infrared spectroscopy (fNIRS) and 2-channel NIRS at Fp1 and Fp2. In 16 subjects, palmar sweating was induced by upgaze and decreased in response to downgaze. Upgaze activated the ventromedial prefrontal cortex with an accumulation of integrated concentration changes in deoxyhemoglobin, oxyhemoglobin, and total hemoglobin levels in 12 subjects. Upgaze phasically and degree-dependently increased deoxyhemoglobin level at Fp1 and Fp2, whereas downgaze phasically decreased it in 16 subjects. Unilateral anesthetization of mechanoreceptors in the supratarsal Müller muscle used to significantly reduce trigeminal proprioceptive evocation ipsilaterally impaired the increased deoxyhemoglobin level by 60° upgaze at Fp1 or Fp2 in 6 subjects. We concluded that upgaze with strong trigeminal proprioceptive evocation was sufficient to phasically activate sympathetically innervated sweat glands

  8. Losing One's Hand: Visual-Proprioceptive Conflict Affects Touch Perception

    PubMed Central

    Folegatti, Alessia; de Vignemont, Frédérique; Pavani, Francesco; Rossetti, Yves; Farnè, Alessandro

    2009-01-01

    Background While the sense of bodily ownership has now been widely investigated through the rubber hand illusion (RHI), very little is known about the sense of disownership. It has been hypothesized that the RHI also affects the ownership feelings towards the participant's own hand, as if the rubber hand replaced the participant's actual hand. Somatosensory changes observed in the participants' hand while experiencing the RHI have been taken as evidence for disownership of their real hand. Here we propose a theoretical framework to disambiguate whether such somatosensory changes are to be ascribed to the disownership of the real hand or rather to the anomalous visuo-proprioceptive conflict experienced by the participant during the RHI. Methodology/Principal Findings In experiment 1, reaction times (RTs) to tactile stimuli delivered to the participants' hand slowed down following the establishment of the RHI. In experiment 2, the misalignment of visual and proprioceptive inputs was obtained via prismatic displacement, a situation in which ownership of the seen hand was doubtless. This condition slowed down the participants' tactile RTs. Thus, similar effects on touch perception emerged following RHI and prismatic displacement. Both manipulations also induced a proprioceptive drift, toward the fake hand in the first experiment and toward the visual position of the participants' hand in the second experiment. Conclusions/Significance These findings reveal that somatosensory alterations in the experimental hand resulting from the RHI result from cross-modal mismatch between the seen and felt position of the hand. As such, they are not necessarily a signature of disownership. PMID:19738900

  9. Neuromechanical models for insect locomotion: Stability, maneuverability, and proprioceptive feedback

    NASA Astrophysics Data System (ADS)

    Kukillaya, R.; Proctor, J.; Holmes, P.

    2009-06-01

    We describe a hierarchy of models for legged locomotion, emphasizing relationships among feedforward (preflexive) stability, maneuverability, and reflexive feedback. We focus on a hexapedal geometry representative of insect locomotion in the ground plane that includes a neural central pattern generator circuit, nonlinear muscles, and a representative proprioceptive sensory pathway. Although these components of the model are rather complex, neglect of leg mass yields a neuromechanical system with only three degrees of freedom, and numerical simulations coupled with a Poincaré map analysis shows that the feedforward dynamics is strongly stable, apart from one relatively slow mode and a neutral mode in body yaw angle. These modes moderate high frequency perturbations, producing slow heading changes that can be corrected by a stride-to-stride steering strategy. We show that the model's response to a lateral impulsive perturbation closely matches that of a cockroach subject to a similar impulse. We also describe preliminary studies of proprioceptive leg force feedback, showing how a reflexive pathway can reinforce the preflexive stability inherent in the system.

  10. On the bimanual integration of proprioceptive information.

    PubMed

    Kuehn, Esther; De Havas, Jack; Silkoset, Emilie; Gomi, Hiroaki; Haggard, Patrick

    2015-04-01

    Proprioception can be defined as the sense for body movement and position. While most sensory information can be successfully integrated across hemispheres, little is known about the bilateral integration of proprioceptive information. In two behavioural experiments, we investigated whether estimates of the position of one hand are influenced by simultaneous proprioceptive information from the other hand. We further investigated whether such putative bimanual proprioceptive integration would differ between expert dancers and non-dancer controls. Either one hand or both hands were passively moved to novel positions, and participants indicated the perceived location of the index finger tip of the designated target hand, by orienting a visible laser beam mounted on a cap. Synchronized bimanual movements compared to unimanual movements significantly improved proprioceptive position sense. In particular, we found a bias reduction to perceive the target hand's index finger tip as shifted away from the midline in the bimanual condition, compared to the unimanual condition. Expert dancers, in contrast, did not show this change in proprioceptive position sense after bimanual movements. We suggest that bimanual movements may improve proprioception due to interhemispheric integration in controls, but not in expert dancers.

  11. Subdiaphragmatic vagal deafferentation fails to block the anorectic effect of hydroxycitrate.

    PubMed

    Leonhardt, Monika; Hrupka, Brian J; Langhans, Wolfgang

    2004-09-15

    We investigated the neural mediation of the feeding suppression through orally administered hydroxycitrate (HCA) in male rats that were fed a high-glucose diet (about 48% glucose). Ten-day ad libitum food intake and body weight regain after previous body weight loss (13% of initial body weight) due to restrictive feeding were measured in rats with sham deafferentation (SHAM; n = 6), subdiaphragmatic vagal deafferentation (SDA; n = 7), and SDA plus celiac-superior mesenteric ganglionectomy (SDA/CGX; n = 9). HCA suppressed the 10-day cumulative food intake in all surgical groups and body weight regain in SDA and SDA/CGX groups. Independent of HCA, SDA and SDA/CGX rats consumed less food and gained less weight compared to SHAM rats. These results demonstrate that all vagal afferents from below the diaphragm and vagal efferents of the dorsal trunk as well as splanchnic nerves (afferents and efferents) are not necessary for the feeding-suppressive effect of HCA in this animal model. Vagal afferents, however, appear to play a role in the control of intake when a high-glucose diet is consumed after a period of restrictive feeding. PMID:15276787

  12. Relationship between chronic pain and brain reorganization after deafferentation: A systematic review of functional MRI findings☆

    PubMed Central

    Jutzeler, C.R.; Curt, A.; Kramer, J.L.K.

    2015-01-01

    Background Mechanisms underlying the development of phantom limb pain and neuropathic pain after limb amputation and spinal cord injury, respectively, are poorly understood. The goal of this systematic review was to assess the robustness of evidence in support of “maladaptive plasticity” emerging from applications of advanced functional magnetic resonance imaging (MRI). Methods Using MeSH heading search terms in PubMed and SCOPUS, a systematic review was performed querying published manuscripts. Results From 146 candidate publications, 10 were identified as meeting the inclusion criteria. Results from fMRI investigations provided some level of support for maladaptive cortical plasticity, including longitudinal studies that demonstrated a change in functional organization related to decreases in pain. However, a number of studies have reported no relationship between reorganization, pain and deafferentation, and emerging evidence has also suggested the opposite — that is, chronic pain is associated with preserved cortical function. Conclusion Based solely on advanced functional neuroimaging results, there is only limited evidence for a relationship between chronic pain intensity and reorganization after deafferentation. The review demonstrates the need for additional neuroimaging studies to clarify the relationship between chronic pain and reorganization. PMID:26740913

  13. Strength Training and Shoulder Proprioception

    PubMed Central

    Salles, José Inácio; Velasques, Bruna; Cossich, Victor; Nicoliche, Eduardo; Ribeiro, Pedro; Amaral, Marcus Vinicius; Motta, Geraldo

    2015-01-01

    Context: Proprioception is essential to motor control and joint stability during daily and sport activities. Recent studies demonstrated that athletes have better joint position sense (JPS) when compared with controls matched for age, suggesting that physical training could have an effect on proprioception. Objective: To evaluate the result of an 8-week strength-training program on shoulder JPS and to verify whether using training intensities that are the same or divergent for the shoulder's dynamic-stabilizer muscles promote different effects on JPS. Design: Randomized controlled clinical trial. Setting: We evaluated JPS in a research laboratory and conducted training in a gymnasium. Patients or Other Participants: A total of 90 men, right handed and asymptomatic, with no history of any type of injury or shoulder instability. Intervention(s): For 8 weeks, the participants performed the strength-training program 3 sessions per week. We used 4 exercises (bench press, lat pull down, shoulder press, and seated row), with 2 sets each. Main Outcome Measure(s): We measured shoulder JPS acuity by calculating the absolute error. Results: We found an interaction between group and time. To examine the interaction, we conducted two 1-way analyses of variance comparing groups at each time. The groups did not differ at pretraining; however, a difference among groups was noted posttraining. Conclusions: Strength training using exercises at the same intensity produced an improvement in JPS compared with exercises of varying intensity, suggesting that the former resulted in improvements in the sensitivity of muscle spindles and, hence, better neuromuscular control in the shoulder. PMID:25594912

  14. Falls study: Proprioception, postural stability, and slips.

    PubMed

    Sohn, Jeehoon; Kim, Sukwon

    2015-01-01

    The present study evaluated effects of exercise training on the proprioception sensitivity, postural stability, and the likelihood of slip-induced falls. Eighteen older adults (6 in balance, 6 in weight, and 6 in control groups) participated in this study. Three groups met three times per week over the course of eight weeks. Ankle and knee proprioception sensitivities and postural stability were measured. Slip-induced events were introduced for all participants before and after training. The results indicated that, overall, strength and postural stability were improved only in the training group, although proprioception sensitivity was improved in all groups. Training for older adults resulted in decreased likelihood of slip-induced falls. The study suggested that proprioception can be improved by simply being active, however, the results suggested that training would aid older adults in reducing the likelihood of slip-induced falls.

  15. Falls study: Proprioception, postural stability, and slips.

    PubMed

    Sohn, Jeehoon; Kim, Sukwon

    2015-01-01

    The present study evaluated effects of exercise training on the proprioception sensitivity, postural stability, and the likelihood of slip-induced falls. Eighteen older adults (6 in balance, 6 in weight, and 6 in control groups) participated in this study. Three groups met three times per week over the course of eight weeks. Ankle and knee proprioception sensitivities and postural stability were measured. Slip-induced events were introduced for all participants before and after training. The results indicated that, overall, strength and postural stability were improved only in the training group, although proprioception sensitivity was improved in all groups. Training for older adults resulted in decreased likelihood of slip-induced falls. The study suggested that proprioception can be improved by simply being active, however, the results suggested that training would aid older adults in reducing the likelihood of slip-induced falls. PMID:26406065

  16. Minimally assistive robot training for proprioception enhancement.

    PubMed

    Casadio, Maura; Morasso, Pietro; Sanguineti, Vittorio; Giannoni, Psiche

    2009-04-01

    In stroke survivors, motor impairment is frequently associated with degraded proprioceptive and/or somatosensory functions. Here we address the question of how to use robots to improve proprioception in these patients. We used an 'assist-as-needed' protocol, in which robot assistance was kept to a minimum and was continuously adjusted during exercise. To specifically train proprioceptive functions, we alternated blocks of trials with and without vision. A total of nine chronic stroke survivors participated in the study, which consisted of a total of ten 1-h exercise sessions. We used a linear mixed-effects statistical model to account for the effects of exercise, vision and the degree of assistance on the overall performance, and to capture both the systematic effects and the individual variations. Although there was not always a complete recovery of autonomous movements, all subjects exhibited an increased amount of voluntary control. Moreover, training with closed eyes appeared to be beneficial for patients with abnormal proprioception. Our results indicate that training by alternating vision and no-vision blocks may improve the ability to use proprioception as well as the ability to integrate it with vision. We suggest that the approach may be useful in the more general case of motor skill acquisition, in which enhancing proprioception may improve the ability to physically interact with the external world. PMID:19139867

  17. Minimally assistive robot training for proprioception enhancement.

    PubMed

    Casadio, Maura; Morasso, Pietro; Sanguineti, Vittorio; Giannoni, Psiche

    2009-04-01

    In stroke survivors, motor impairment is frequently associated with degraded proprioceptive and/or somatosensory functions. Here we address the question of how to use robots to improve proprioception in these patients. We used an 'assist-as-needed' protocol, in which robot assistance was kept to a minimum and was continuously adjusted during exercise. To specifically train proprioceptive functions, we alternated blocks of trials with and without vision. A total of nine chronic stroke survivors participated in the study, which consisted of a total of ten 1-h exercise sessions. We used a linear mixed-effects statistical model to account for the effects of exercise, vision and the degree of assistance on the overall performance, and to capture both the systematic effects and the individual variations. Although there was not always a complete recovery of autonomous movements, all subjects exhibited an increased amount of voluntary control. Moreover, training with closed eyes appeared to be beneficial for patients with abnormal proprioception. Our results indicate that training by alternating vision and no-vision blocks may improve the ability to use proprioception as well as the ability to integrate it with vision. We suggest that the approach may be useful in the more general case of motor skill acquisition, in which enhancing proprioception may improve the ability to physically interact with the external world.

  18. Effect of auditory deafferentation on the synaptic connectivity of a pair of identified interneurons in adult field crickets.

    PubMed

    Brodfuehrer, P D; Hoy, R R

    1988-01-01

    In adult crickets, Teleogryllus oceanicus, unilateral auditory deafferentation causes the medial dendrites of an afferent-deprived, identified auditory interneuron (Int-1) in the prothoracic ganglion to sprout and form new functional connections in the contralateral auditory neuropil. The establishment of these new functional connections by the deafferented Int-1, however, does not appear to affect the physiological responses of Int-1's homolog on the intact side of the prothoracic ganglion which also innervates this auditory neuropil. Thus it appears that the sprouting dendrites of the deafferented Int-1 are not functionally competing with those of the intact Int-1 for synaptic connections in the remaining auditory neuropil following unilateral deafferentation in adult crickets. Moreover, we demonstrate that auditory function is restored to the afferent-deprived Int-1 within 4-6 days following deafferentation, when few branches of Int-1's medial dendrites can be seen to have sprouted. The strength of the physiological responses and extent of dendritic sprouting in the deafferented Int-1 progressively increase with time following deafferentation. By 28 days following deafferentation, most of the normal physiological responses of Int-1 to auditory stimuli have been restored in the deafferented Int-1, and the medial dendrites of the deafferented Int-1 have clearly sprouted and grown across into the contralateral auditory afferent field. The strength of the physiological responses of the deafferented Int-1 to auditory stimuli and extent of dendritic sprouting in the deafferented Int-1 are greater in crickets deafferented as juveniles than as adults. Thus, neuronal plasticity persists in Int-1 following sensory deprivation from the earliest juvenile stages through adulthood.

  19. Lithium increases bcl-2 expression in chick cochlear nucleus and protects against deafferentation-induced cell death.

    PubMed

    Bush, A L; Hyson, R L

    2006-01-01

    Approximately 20-30% of neurons in the avian cochlear nucleus (nucleus magnocellularis) die following deafferentation (i.e. deafness produced by cochlea removal) and the remaining neurons show a decrease in soma size. Cell death is generally accepted to be a highly regulated process involving various pro-survival and pro-death molecules. One treatment that has been shown to modify the expression of these molecules is chronic administration of lithium. The present experiments examined whether lithium treatment can protect neurons from deafferentation-induced cell death. Post-hatch chicks were treated with LiCl or saline for 17 consecutive days, beginning on the day of hatching. On the 17th day, a unilateral cochlea ablation was performed. Five days following surgery, the nucleus magnocellularis neurons were counted stereologically on opposite sides of the same brains. Lithium reduced deafferentation-induced cell death by more than 50% (9.8% cell death as compared with 22.4% in saline-treated subjects). Lithium did not affect cell number on the intact side of the brain. Lithium also did not prevent the deafferentation-induced decrease in soma size, suggesting a dissociation between the mechanisms involved in the afferent control of soma size and those involved in the afferent control of cell viability. A possible mechanism for lithium's neuroprotective influence was examined in a second set of subjects. Previous studies suggest that the pro-survival molecule, bcl-2, may play a role in regulating cell death following deafferentation. Tissues from lithium- and saline-treated subjects were examined using immunocytochemistry. Chronic administration of lithium dramatically increased the expression of bcl-2 protein in nucleus magnocellularis neurons. These data suggest that lithium may impart its neuroprotective effect by altering the expression of molecules that regulate cell death.

  20. Basal dendritic length is reduced in the rat hippocampus following bilateral vestibular deafferentation.

    PubMed

    Balabhadrapatruni, Sangeeta; Zheng, Yiwen; Napper, Ruth; Smith, Paul F

    2016-05-01

    Some previous studies in humans have shown that bilateral loss of vestibular function is associated with a significant bilateral atrophy of the hippocampus, which correlated with the patients' spatial memory deficits. By contrast, studies in rats have failed to detect any changes in hippocampal volume following bilateral vestibular loss. Therefore, in this study we investigated whether bilateral vestibular deafferentation (BVD) might result in more subtle morphological changes in the rat hippocampus, involving alterations in dendritic intersections, using Golgi staining and Sholl analysis. We found that at 1month following BVD, there was a significant decrease in basal (P⩽0.0001) but not apical dendritic intersections in the CA1 region of the hippocampus compared to sham-operated animals and anaesthetic controls. However, dendritic branching was not significantly affected. These results suggest that the rat hippocampus does undergo subtle morphological changes following bilateral vestibular loss, and that they may be in the form of alterations in dendritic structure. PMID:26976094

  1. Activation of the hypothalamic-pituitary-adrenal axis following vestibular deafferentation in pigmented guinea pig.

    PubMed

    Gliddon, Catherine M; Darlington, Cynthia L; Smith, Paul F

    2003-02-28

    Twelve male pigmented guinea pigs underwent either a unilateral vestibular deafferentation (UVD) (n=6) or sham operation (n=6). Compared to the pre-operated salivary cortisol concentrations, the UVD operation resulted in a significant increase in night cortisol concentrations (P<0.05) and a significant interaction between the night cortisol concentration and time (P<0.05). There was no significant difference between the pre- and post-UVD morning salivary cortisol concentrations; nor between the pre- and post-sham morning or night salivary cortisol concentrations. This study suggests that the ocular-motor and postural syndrome is causing the activation of the hypothalamic-pituitary-adrenal (HPA) axis. PMID:12576192

  2. Experimental tonic hand pain modulates the corticospinal plasticity induced by a subsequent hand deafferentation.

    PubMed

    Mavromatis, N; Gagné, M; Voisin, J I A V; Reilly, K T; Mercier, C

    2016-08-25

    Sensorimotor reorganization is believed to play an important role in the development and maintenance of phantom limb pain, but pain itself might modulate sensorimotor plasticity induced by deafferentation. Clinical and basic research support this idea, as pain prior to amputation increases the risk of developing post-amputation pain. The aim of this study was to examine the influence of experimental tonic cutaneous hand pain on the plasticity induced by temporary ischemic hand deafferentation. Sixteen healthy subjects participated in two experimental sessions (Pain, No Pain) in which transcranial magnetic stimulation was used to assess corticospinal excitability in two forearm muscles (flexor carpi radialis and flexor digitorum superficialis) before (T0, T10, T20, and T40) and after (T60 and T75) inflation of a cuff around the wrist. The cuff was inflated at T45 in both sessions and in the Pain session capsaicin cream was applied on the dorsum of the hand at T5. Corticospinal excitability was significantly greater during the Post-inflation phase (p=0.002) and increased similarly in both muscles (p=0.861). Importantly, the excitability increase in the Post-inflation phase was greater for the Pain than the No-Pain condition (p=0.006). Post-hoc analyses revealed a significant difference between the two conditions during the Post-inflation phase (p=0.030) but no difference during the Pre-inflation phase (p=0.601). In other words, the corticospinal facilitation was greater when pain was present prior to cuff inflation. These results indicate that pain can modulate the plasticity induced by another event, and could partially explain the sensorimotor reorganization often reported in chronic pain populations. PMID:27291642

  3. Olfactory bulb recovery following reversible deafferentation with repeated detergent application in the adult zebrafish.

    PubMed

    Paskin, T R; Iqbal, T R; Byrd-Jacobs, C A

    2011-11-24

    The neuroplasticity and regenerative properties of the olfactory system make it a useful model for studying the ability of the nervous system to recover from damage. We have developed a novel method for examining the effects of long-term deafferentation and regeneration of the olfactory organ and resulting influence on the olfactory bulb in adult zebrafish. To test the hypothesis that repeated damage to the olfactory epithelium causes reduced olfactory bulb afferent input and cessation of treatment allows recovery, we chronically ablated the olfactory organ every 2-3 days for 3 weeks with the detergent Triton X-100 while another group was allowed 3 weeks of recovery following treatment. Animals receiving chronic treatment showed severe morphological disruption of the olfactory organ, although small pockets of epithelium remained. These pockets were labeled by anti-calretinin, indicating the presence of mature olfactory sensory neurons (OSNs). Following a recovery period, the epithelium was more extensive and neuronal labeling increased, with three different morphologies of sensory neurons observed. Repeated peripheral exposure to Triton X-100 also affected the olfactory bulb. Bulb volumes and anti-tyrosine hydroxylase-like immunoreactivity, which is an indicator of afferent activity, were diminished in the olfactory bulb of the chronically treated group compared to the control side. In the recovery group, there was little difference in bulb volume or antibody staining. These results suggest that repeated, long-term nasal irrigation with Triton X-100 eliminates a substantial number of mature OSNs and reduces afferent input to the olfactory bulb. It also appears that these effects are reversible and regeneration will occur in both the peripheral olfactory organ and the olfactory bulb when given time to recover following cessation of treatment. We report here a new method that allows observation not only of the effects of deafferentation on the olfactory bulb but also

  4. Impaired vertical postural control and proprioceptive integration deficits in Parkinson's disease.

    PubMed

    Vaugoyeau, M; Viel, S; Assaiante, C; Amblard, B; Azulay, J P

    2007-05-11

    The aim of the present study was to investigate how the orientation and stabilization components of postural control may be affected as the result of the impaired proprioceptive integration possibly occurring in Parkinson's disease. To determine the proprioceptive contribution to postural control, parkinsonian patients and control subjects were asked to maintain vertical stance while very slow sinusoidal oscillations were being applied in the lateral and antero-posterior planes to the platform on which they were standing. The amplitude and frequency of their movements were kept below the semicircular canal perception threshold. Data were collected with the ELITE automatic motion analyzer and the two postural components (orientation and segmental stabilization) were analyzed at head and trunk levels while the subjects were performing the task with their eyes open and closed. The results show that 1) the parkinsonian groups' performances were affected in terms of both the postural orientation and stabilization components in comparison with the control group, 2) the use of vision improved the parkinsonian patients' postural performances, and 3) both parkinsonian patients and control subjects achieved better postural performances when antero-posterior perturbations rather than lateral perturbations were applied to the foot support. These results suggest that Parkinson's disease is associated with proprioceptive impairment, which may be an important factor contributing to these patients' postural deficits. On the basis of these results, the visual dependence observed in parkinsonian patients is re-defined as an adaptive strategy partly compensating for the impaired proprioception.

  5. Artificial proprioceptive feedback for myoelectric control.

    PubMed

    Pistohl, Tobias; Joshi, Deepak; Ganesh, Gowrishankar; Jackson, Andrew; Nazarpour, Kianoush

    2015-05-01

    The typical control of myoelectric interfaces, whether in laboratory settings or real-life prosthetic applications, largely relies on visual feedback because proprioceptive signals from the controlling muscles are either not available or very noisy. We conducted a set of experiments to test whether artificial proprioceptive feedback, delivered noninvasively to another limb, can improve control of a two-dimensional myoelectrically-controlled computer interface. In these experiments, participants were required to reach a target with a visual cursor that was controlled by electromyogram signals recorded from muscles of the left hand, while they were provided with an additional proprioceptive feedback on their right arm by moving it with a robotic manipulandum. Provision of additional artificial proprioceptive feedback improved the angular accuracy of their movements when compared to using visual feedback alone but did not increase the overall accuracy quantified with the average distance between the cursor and the target. The advantages conferred by proprioception were present only when the proprioceptive feedback had similar orientation to the visual feedback in the task space and not when it was mirrored, demonstrating the importance of congruency in feedback modalities for multi-sensory integration. Our results reveal the ability of the human motor system to learn new inter-limb sensory-motor associations; the motor system can utilize task-related sensory feedback, even when it is available on a limb distinct from the one being actuated. In addition, the proposed task structure provides a flexible test paradigm by which the effectiveness of various sensory feedback and multi-sensory integration for myoelectric prosthesis control can be evaluated.

  6. Delayed early proprioceptive information processing in schizophrenia.

    PubMed

    Arnfred, Sidse M; Hemmingsen, Ralf P; Parnas, Josef

    2006-12-01

    It was first suggested that disordered proprioception was a core feature of schizophrenia by Sandor Rado in 1953. Using a recently designed proprioceptive event-related potential paradigm based on a change of load, we studied 12 unmedicated male out-patients with schizophrenia and 24 controls. In the patients, the early contralateral parietal activity was delayed and later central activity had increased amplitude, but gating was unaffected. The results could be understood within the "deficiency of corollary discharge" model of schizophrenia but not within the "filtering" theory. Further studies, including psychiatric controls, are necessary to verify the specificity of the abnormality.

  7. Proprioceptive versus Visual Control in Autistic Children.

    ERIC Educational Resources Information Center

    Masterton, B. A.; Biederman, G. B.

    1983-01-01

    The autistic children's presumed preference for proximal over distal sensory input was studied by requiring that "autistic," retarded, and "normal" children (7-15 years old) adapt to lateral displacement of the visual field. Only autistic Ss demonstrated transfer of adaptation to the nonadapted hand, indicating reliance on proprioception rather…

  8. Dynamic Flexibility and Proprioceptive Neuromuscular Facilitation.

    ERIC Educational Resources Information Center

    Hardy, Lew; Jones, David

    1986-01-01

    Two experiments are described which investigated whether results obtained in studies of static flexibility tranfer to dynamic flexibility. In both experiments, subjects were assigned to a group receiving proprioceptive neuromuscular facilitation training, ballistic stretching technique training or a control group. Results are presented and…

  9. Cooling Does Not Affect Knee Proprioception

    PubMed Central

    Ozmun, John C.; Thieme, Heather A.; Ingersoll, Christopher D.; Knight, Kenneth L.

    1996-01-01

    The effect of cooling on proprioception of the knee has not been studied extensively. In this study, we investigated the movement reproduction (timing and accuracy) aspect of proprioception. Subjects were tested under two conditions: a 20-minute application of ice and control. Proprioceptive accuracy and timing were measured by passively moving the knee, then comparing the subject's active reproduction of the passive movement. Subjects were blindfolded, then tested in three sectors of the knee's range of motion: 90° to 60°, 60° to 30°, and 30° to full extension. Ice application had no apparent effect on the subject's ability to perform accurate movement reproductions in the sectors tested. However, accuracy of the subject's final angle reproduction varied between the sectors as did the total time of the movement. One possible explanation for the difference between sectors is that different receptors are active at different points in the knee's range of motion. We conclude that cooling the knee joint for 20 minutes does not have an adverse effect on proprioception. PMID:16558379

  10. Compensatory saccades benefit from prediction during head impulse testing in early recovery from vestibular deafferentation.

    PubMed

    Mantokoudis, Georgios; Agrawal, Yuri; Newman-Toker, David E; Xie, Li; Saber Tehrani, Ali S; Wong, Aaron; Schubert, Michael C

    2016-06-01

    The head impulse test (HIT) can identify a deficient vestibulo-ocular reflex (VOR) by the compensatory saccade (CS) generated once the head stops moving. The inward HIT is considered safer than the outward HIT, yet might have an oculomotor advantage given that the subject would presumably know the direction of head rotation. Here, we compare CS latencies following inward (presumed predictable) and outward (more unpredictable) HITs after acute unilateral vestibular nerve deafferentation. Seven patients received inward and outward HITs delivered at six consecutive postoperative days (POD) and again at POD 30. All head impulses were recorded by portable video-oculography. CS included those occurring during (covert) or after (overt) head rotation. Inward HITs included mean CS latencies (183.48 ms ± 4.47 SE) that were consistently shorter than those generated during outward HITs in the first 6 POD (p = 0.0033). Inward HITs induced more covert saccades compared to outward HITs, acutely. However, by POD 30 there were no longer any differences in latencies or proportions of CS and direction of head rotation. Patients with acute unilateral vestibular loss likely use predictive cues of head direction to elicit early CS to keep the image centered on the fovea. In acute vestibular hypofunction, inwardly applied HITs may risk a preponderance of covert saccades, yet this difference largely disappears within 30 days. Advantages of inwardly applied HITs are discussed and must be balanced against the risk of a false-negative HIT interpretation.

  11. Cell bodies of the trigeminal proprioceptive neurons that transmit reflex contraction of the levator muscle are located in the mesencephalic trigeminal nucleus in rats.

    PubMed

    Fujita, Kenya; Matsuo, Kiyoshi; Yuzuriha, Shunsuke; Kawagishi, Kyutaro; Moriizumi, Tetsuji

    2012-12-01

    Since the levator and frontalis muscles lack interior muscle spindles despite being antigravity mixed muscles to involuntarily sustain eyelid opening and eyebrow lifting, this study has proposed a hypothetical mechanism to compensate for this anatomical defect. The voluntary contraction of fast-twitch fibres of the levator muscle stretches the mechanoreceptors in Müller's muscle to evoke proprioception, which continuously induces reflex contraction of slow-twitch fibres of the levator and frontalis muscles. This study confirmed the presence of cell bodies of the trigeminal proprioceptive neurons that transmit reflex contraction of the levator and frontalis muscles. After confirming that severing the trigeminal proprioceptive fibres that innervate the mechanoreceptors in Müller's muscle induced ipsilateral eyelid ptosis, Fluorogold was applied as a tracer to the proximal stump of the trigeminal proprioceptive nerve in rats. Fluorogold labelled the cell bodies of the trigeminal proprioceptive neurons, not in any regions of the rat brain including the trigeminal ganglion, but in the ipsilateral mesencephalic trigeminal nucleus neighbouring the locus ceruleus. Some Fluorogold particles accumulated in the area of the locus ceruleus. The trigeminal proprioceptive neurons could be considered centrally displaced ganglion cells to transmit afferent signal from the mechanoreceptors in Müller's muscle to the mesencephalon, where they may be able to make excitatory synaptic connections with both the oculomotor neurons and the frontalis muscle motoneurons for the involuntary coordination of the eyelid and eyebrow activities, and potentially to the locus ceruleus.

  12. Effect of unilateral vestibular deafferentation on the initial human vestibulo-ocular reflex to surge translation

    PubMed Central

    Tian, Jun-Ru; Ishiyama, Akira; Demer, Joseph L.

    2007-01-01

    Transient whole-body surge (fore-aft) translation at 0.5 G peak acceleration was administered to six subjects with unilateral vestibular deafferentation (UVD), and eight age-matched controls. Subjects viewed eccentric targets to determine if linear vestibulo-ocular reflex (LVOR) asymmetry might lateralize otolith deficits. Eye rotation was measured using magnetic search coils. Immediately before surge, subjects viewed a luminous target 50 cm away, centered or displaced 10° horizontally or vertically. The target was extinguished during randomly directed surges. LVOR gain relative to ideal velocity in subjects with UVD for the contralesional horizontally eccentric target (0.59 ± 0.08, mean ± SEM) did not differ significantly from normal (0.50 ± 0.04), but gain for the ipsilesional eccentric target (0.35 ± 0.02) was significantly less than normal (0.48 ± 0.03, P < 0.05). Normal subjects had mean gain asymmetry for horizontally eccentric targets of 0.17 ± 0.03, but asymmetry in UVD was significantly increased to 0.35 ± 0.05 (P < 0.05). Four of six subjects with UVD had maximum gain asymmetry outside normal 95% confidence limits. Asymmetry did not correlate with UVD duration. Gain for 10° vertically eccentric targets averaged 0.38 ± 0.14 for subjects with UVD, insignificantly lower than the normal value of 0.75 ± 0.15 (P > 0.05). Surge LVOR latency was symmetrical in UVD, and did not differ significantly from normal. There was no significant difference in response between dark and visible target conditions until 200 ms after surge onset. Chronic human UVD, on average, significantly impairs the surge LVOR for horizontally eccentric targets placed ipsilesionally, but this asymmetry is small relative to interindividual variation. PMID:16900361

  13. The consequences of gustatory deafferentation on body mass and feeding patterns in the rat

    PubMed Central

    Colbert, Connie L.; Garcea, Mircea; Smith, James C.; Spector, Alan C.

    2012-01-01

    The contribution of orosensory signals, especially taste, on body mass, and feeding and drinking patterns in the rat was examined. Gustatory deafferentation was produced by bilateral transection of the chorda tympani, glossopharyngeal, and greater superficial petrosal nerves. Total calories consumed from sweetened-milk diet and oil-chow mash by the nerve-transected rats significantly decreased relative to sham-operated controls, mostly attributable to decreases in bout number, but not size. Nevertheless, caloric intake steadily increased over the postsurgical observation period, but body mass remained below both presurgical baseline and control levels and did not significantly increase over this time. After the sweetened-milk diet/oil-chow mash phase, rats received a series of sucrose preference tests. Interestingly, the nerve-transected rats preferred sucrose, and intake did not differ from controls, likely due to the stimulus sharing some nontaste chemosensory properties with the sweetened-milk diet. The neurotomized rats initiated a greater number of sucrose-licking bouts that were smaller in size and slower in licking rate, compared with control rats, and, unlike in control rats, the latter two bout parameters did not vary across concentration. Thus, in the absence of gustatory neural input, body mass is more stable compared with the progressive trajectory of weight gain seen in intact rats, and caloric intake initially decreases but recovers. The consequences of gustatory neurotomy on processes that determine meal initiation (bout number) and meal termination (bout size) are not fixed and appear to be influenced by presurgical experience with food stimuli coupled with its nongustatory chemosensory properties. PMID:22785426

  14. Wrist Proprioception: Amplitude or Position Coding?

    PubMed Central

    Marini, Francesca; Squeri, Valentina; Morasso, Pietro; Masia, Lorenzo

    2016-01-01

    This work examines physiological mechanisms underlying the position sense of the wrist, namely, the codification of proprioceptive information related to pointing movements of the wrist toward kinesthetic targets. Twenty-four healthy subjects participated to a robot-aided assessment of their wrist proprioceptive acuity to investigate if the sensorimotor transformation involved in matching targets located by proprioceptive receptors relies on amplitude or positional cues. A joint position matching test was performed in order to explore such dichotomy. In this test, the wrist of a blindfolded participant is passively moved by a robotic device to a preset target position and, after a removal movement from this position, the participant has to actively replicate and match it as accurately as possible. The test involved two separate conditions: in the first, the matching movements started from the same initial location; in the second one, the initial location was randomly assigned. Target matching accuracy, precision, and bias in the two conditions were then compared. Overall results showed a consistent higher performance in the former condition than in the latter, thus supporting the hypothesis that the joint position sense is based on vectorial or amplitude coding rather than positional. PMID:27807417

  15. The Effect of Chronic Deafferentation on Mental Imagery: A Case Study

    PubMed Central

    ter Horst, Arjan C.; Cole, Jonathan; van Lier, Rob; Steenbergen, Bert

    2012-01-01

    Visual- and motor imagery rely primarily on perceptual and motor processes, respectively. In healthy controls, the type of imagery used to solve a task depends on personal preference, task instruction, and task properties. But how does the chronic loss of proprioceptive and tactile sensory inputs from the body periphery influence mental imagery? In a unique case study, we investigated the imagery capabilities of the chronically deafferented patient IW when he was performing a mental rotation task. We found that IW's motor imagery processes were impaired and that visual imagery processes were enhanced compared to controls. These results suggest that kinaesthetic afferent signals from the body periphery play a crucial role in enabling and maintaining central sensorimotor representations and hence the ability to incorporate kinaesthetic information into the imagery processes. PMID:22880095

  16. The Effects of Patellar Taping on Knee Joint Proprioception

    PubMed Central

    Callaghan, Michael J.; Selfe, James; Bagley, Pam J.; Oldham, Jacqueline A.

    2002-01-01

    Objective: To evaluate the effects of patellar taping on knee joint proprioception. Design and Setting: In a research unit, 3 proprioceptive tests were performed. For each of the tests, a standardized patellar taping technique was applied in random order. Subjects: Fifty-two healthy volunteers (27 women, 25 men; age, 23.2 ± 4.6 years; body mass index, 23.3 ± 3.7). Measurements: We measured active angle reproduction, passive angle reproduction, and threshold to detection of passive movement on an isokinetic dynamometer. Results: We found no significant differences between the tape and no-tape conditions in any of the 3 proprioceptive tests (P > .05). However, when the subjects' results for active angle reproduction and passive angle reproduction were graded as good (≤5°) and poor (>5°), taping was found to improve significantly those with poor proprioceptive ability (P < .01). Conclusions: Subjects with good proprioception did not benefit from patellar taping. However, in those healthy subjects with poor proprioceptive ability as measured by active and passive ankle reproduction, patellar taping provided proprioceptive enhancement. Further studies are needed to investigate the effect of patellar taping on the proprioceptive status of patients with patellofemoral pain syndrome. PMID:12937439

  17. Visual-Proprioceptive Intermodal Perception Using Point Light Displays.

    ERIC Educational Resources Information Center

    Schmuckler, Mark A.; Fairhall, Jennifer L.

    2001-01-01

    Three experiments explored 5- and 7-month-olds' intermodal coordination of proprioceptive information produced by leg movements and visual movement information specifying these same motions. Results suggested that coordination of visual and proprioceptive inputs is constrained by infants' information processing of the displays and have…

  18. Evaluation of Knee Proprioception and Factors Related to Parkinson's Disease.

    PubMed

    Ribeiro Artigas, Nathalie; Eltz, Giovana Duarte; do Pinho, Alexandre Severo; Torman, Vanessa Bielefeldt Leotti; Hilbig, Arlete; Rieder, Carlos R M

    2016-01-01

    Background. Changes in proprioception may contribute to postural instability in individuals with neurological disorders. Objectives. Evaluate proprioception in the lower limbs of patients with Parkinson's disease (PD) and the association between proprioception and cognitive ability, motor symptoms, postural instability, and disease severity. Methods. This is a cross-sectional, controlled study that evaluated proprioception in PD patients and healthy age- and sex-matched individuals. Kinetic postural proprioception of the knee was evaluated using an isokinetic dynamometer (Biodex® Multi-Joint System 4 Pro). Participants were evaluated using the Montreal Cognitive Assessment (MoCA), the Hoehn and Yahr rating scale and postural instability (pull test and stabilometric analysis), and motor function (UPDRS-III) tests. Results. A total of 40 individuals were enrolled in the study: 20 PD patients and 20 healthy controls (CG). The PD patients had higher angular errors on the proprioceptive ratings than the CG participants (p = 0.002). Oscillations of the center of pressure (p = 0.002) were higher in individuals with PD than in the controls. Proprioceptive errors in the PD patients were associated with the presence of tremors as the dominant symptom and more impaired motor performance. Conclusion. These findings show that individuals with PD have proprioceptive deficits, which are related to decreased cognitive ability and impaired motor symptoms. PMID:27672650

  19. Evaluation of Knee Proprioception and Factors Related to Parkinson's Disease

    PubMed Central

    Eltz, Giovana Duarte; Torman, Vanessa Bielefeldt Leotti

    2016-01-01

    Background. Changes in proprioception may contribute to postural instability in individuals with neurological disorders. Objectives. Evaluate proprioception in the lower limbs of patients with Parkinson's disease (PD) and the association between proprioception and cognitive ability, motor symptoms, postural instability, and disease severity. Methods. This is a cross-sectional, controlled study that evaluated proprioception in PD patients and healthy age- and sex-matched individuals. Kinetic postural proprioception of the knee was evaluated using an isokinetic dynamometer (Biodex® Multi-Joint System 4 Pro). Participants were evaluated using the Montreal Cognitive Assessment (MoCA), the Hoehn and Yahr rating scale and postural instability (pull test and stabilometric analysis), and motor function (UPDRS-III) tests. Results. A total of 40 individuals were enrolled in the study: 20 PD patients and 20 healthy controls (CG). The PD patients had higher angular errors on the proprioceptive ratings than the CG participants (p = 0.002). Oscillations of the center of pressure (p = 0.002) were higher in individuals with PD than in the controls. Proprioceptive errors in the PD patients were associated with the presence of tremors as the dominant symptom and more impaired motor performance. Conclusion. These findings show that individuals with PD have proprioceptive deficits, which are related to decreased cognitive ability and impaired motor symptoms.

  20. Evaluation of Knee Proprioception and Factors Related to Parkinson's Disease

    PubMed Central

    Eltz, Giovana Duarte; Torman, Vanessa Bielefeldt Leotti

    2016-01-01

    Background. Changes in proprioception may contribute to postural instability in individuals with neurological disorders. Objectives. Evaluate proprioception in the lower limbs of patients with Parkinson's disease (PD) and the association between proprioception and cognitive ability, motor symptoms, postural instability, and disease severity. Methods. This is a cross-sectional, controlled study that evaluated proprioception in PD patients and healthy age- and sex-matched individuals. Kinetic postural proprioception of the knee was evaluated using an isokinetic dynamometer (Biodex® Multi-Joint System 4 Pro). Participants were evaluated using the Montreal Cognitive Assessment (MoCA), the Hoehn and Yahr rating scale and postural instability (pull test and stabilometric analysis), and motor function (UPDRS-III) tests. Results. A total of 40 individuals were enrolled in the study: 20 PD patients and 20 healthy controls (CG). The PD patients had higher angular errors on the proprioceptive ratings than the CG participants (p = 0.002). Oscillations of the center of pressure (p = 0.002) were higher in individuals with PD than in the controls. Proprioceptive errors in the PD patients were associated with the presence of tremors as the dominant symptom and more impaired motor performance. Conclusion. These findings show that individuals with PD have proprioceptive deficits, which are related to decreased cognitive ability and impaired motor symptoms. PMID:27672650

  1. The Effects of Patellar Taping on Knee Joint Proprioception.

    PubMed

    Callaghan, Michael J; Selfe, James; Bagley, Pam J; Oldham, Jacqueline A

    2002-03-01

    OBJECTIVE: To evaluate the effects of patellar taping on knee joint proprioception. DESIGN AND SETTING: In a research unit, 3 proprioceptive tests were performed. For each of the tests, a standardized patellar taping technique was applied in random order. SUBJECTS: Fifty-two healthy volunteers (27 women, 25 men; age, 23.2 +/- 4.6 years; body mass index, 23.3 +/- 3.7). MEASUREMENTS: We measured active angle reproduction, passive angle reproduction, and threshold to detection of passive movement on an isokinetic dynamometer. RESULTS: We found no significant differences between the tape and no-tape conditions in any of the 3 proprioceptive tests (P >.05). However, when the subjects' results for active angle reproduction and passive angle reproduction were graded as good (5 degrees ), taping was found to improve significantly those with poor proprioceptive ability (P <.01). CONCLUSIONS: Subjects with good proprioception did not benefit from patellar taping. However, in those healthy subjects with poor proprioceptive ability as measured by active and passive ankle reproduction, patellar taping provided proprioceptive enhancement. Further studies are needed to investigate the effect of patellar taping on the proprioceptive status of patients with patellofemoral pain syndrome.

  2. Visual and proprioceptive interaction in patients with bilateral vestibular loss.

    PubMed

    Cutfield, Nicholas J; Scott, Gregory; Waldman, Adam D; Sharp, David J; Bronstein, Adolfo M

    2014-01-01

    Following bilateral vestibular loss (BVL) patients gradually adapt to the loss of vestibular input and rely more on other sensory inputs. Here we examine changes in the way proprioceptive and visual inputs interact. We used functional magnetic resonance imaging (fMRI) to investigate visual responses in the context of varying levels of proprioceptive input in 12 BVL subjects and 15 normal controls. A novel metal-free vibrator was developed to allow vibrotactile neck proprioceptive input to be delivered in the MRI system. A high level (100 Hz) and low level (30 Hz) control stimulus was applied over the left splenius capitis; only the high frequency stimulus generates a significant proprioceptive stimulus. The neck stimulus was applied in combination with static and moving (optokinetic) visual stimuli, in a factorial fMRI experimental design. We found that high level neck proprioceptive input had more cortical effect on brain activity in the BVL patients. This included a reduction in visual motion responses during high levels of proprioceptive input and differential activation in the midline cerebellum. In early visual cortical areas, the effect of high proprioceptive input was present for both visual conditions but in lateral visual areas, including V5/MT, the effect was only seen in the context of visual motion stimulation. The finding of a cortical visuo-proprioceptive interaction in BVL patients is consistent with behavioural data indicating that, in BVL patients, neck afferents partly replace vestibular input during the CNS-mediated compensatory process. An fMRI cervico-visual interaction may thus substitute the known visuo-vestibular interaction reported in normal subject fMRI studies. The results provide evidence for a cortical mechanism of adaptation to vestibular failure, in the form of an enhanced proprioceptive influence on visual processing. The results may provide the basis for a cortical mechanism involved in proprioceptive substitution of vestibular

  3. Lower-limb proprioceptive awareness in professional ballet dancers.

    PubMed

    Kiefer, Adam W; Riley, Michael A; Shockley, Kevin; Sitton, Candace A; Hewett, Timothy E; Cummins-Sebree, Sarah; Haas, Jacqui G

    2013-09-01

    Enhanced proprioceptive feedback strengthens synergistic muscle groups and stabilizes the coordination of limbs, thus contributing to the movement efficiency of ballet dancers. The present study compared lower-limb proprioceptive awareness in professional ballet dancers to matched controls who had no dance training. Two assessment methods were used to test the hypothesis that ballet dancers would demonstrate increased proprioceptive awareness in the ankle, knee, and hip: 1. a joint-position matching task to assess static proprioceptive joint awareness, and 2. an eyes-closed, quiet standing task to assess both static and dynamic proprioceptive awareness through measures of center of pressure (COP) variability. Results of the matching task indicated that the dancers exhibited greater proprioceptive awareness than controls for all three joints (p < 0.001). Also, dancers were equally aware of the positioning of their ankle, knee, and hip joints (p > 0.05), whereas controls were less aware of their ankle position compared to their knee and hip joints (p < 0.001). Measures indexing COP variability during quiet standing did not differ between groups and thus failed to reflect increased proprioceptive awareness in dancers (all p > 0.05). This indicates that quiet stance may have limited value as a means for evaluating proprioception. These findings provide preliminary evidence that enhanced proprioceptive awareness of lower limb joints should be considered as an evaluative criterion for dancers' ability to learn complex ballet skills. They also indicate that quiet standing tasks may not provide sufficient challenge for dancers' enhanced proprioceptive awareness to manifest. PMID:24069947

  4. Deafferentation causes a loss of presynaptic bombesin receptors and supersensitivity of substance P receptors in the dorsal horn of the cat spinal cord.

    PubMed

    Massari, V J; Shults, C W; Park, C H; Tizabi, Y; Moody, T W; Chronwall, B M; Culver, M; Chase, T N

    1985-09-23

    Bombesin (BN)- and substance P (SP)-containing neurons are found in the dorsal root ganglia, and project to the dorsal horn of the spinal cord. The present study was undertaken to determine if chronic deafferentation of the cat spinal cord would affect BN or SP receptors in the spinal cord. Ten and 30 days after a unilateral lumbosacral dorsal rhizotomy, BN and SP receptor binding was evaluated autoradiographically using iodinated ligands to bind to these receptors in vitro. The normal distribution of BN receptors detected by this method was restricted to the head of the dorsal horn. Deafferentation caused a 38% and 22% decline in BN receptor binding in laminae I-IV at 10 or 30 days postoperatively, respectively. These data suggest that 'presynaptic' BN receptors are found on the central nervous system terminals of primary sensory afferents. Normal SP receptor distribution was most dense in lamina X, not in the superficial laminae of the dorsal horn. Deafferentation caused an initial decline in SP receptor binding in laminae I-II, followed by a 14% increase at 30 days in comparison to the unoperated side of the spinal cord. This delayed supersensitivity of SP receptors was confirmed in a separate experiment using a homogenate binding assay. These data are discussed with respect to the potential roles of receptor supersensitivity or subsensitivity in the development of deafferentation-induced changes in reactivity of dorsal horn neurons to nociceptive and non-nociceptive stimuli. PMID:2413960

  5. Proprioceptive feedback determines visuomotor gain in Drosophila

    PubMed Central

    Bartussek, Jan; Lehmann, Fritz-Olaf

    2016-01-01

    Multisensory integration is a prerequisite for effective locomotor control in most animals. Especially, the impressive aerial performance of insects relies on rapid and precise integration of multiple sensory modalities that provide feedback on different time scales. In flies, continuous visual signalling from the compound eyes is fused with phasic proprioceptive feedback to ensure precise neural activation of wing steering muscles (WSM) within narrow temporal phase bands of the stroke cycle. This phase-locked activation relies on mechanoreceptors distributed over wings and gyroscopic halteres. Here we investigate visual steering performance of tethered flying fruit flies with reduced haltere and wing feedback signalling. Using a flight simulator, we evaluated visual object fixation behaviour, optomotor altitude control and saccadic escape reflexes. The behavioural assays show an antagonistic effect of wing and haltere signalling on visuomotor gain during flight. Compared with controls, suppression of haltere feedback attenuates while suppression of wing feedback enhances the animal’s wing steering range. Our results suggest that the generation of motor commands owing to visual perception is dynamically controlled by proprioception. We outline a potential physiological mechanism based on the biomechanical properties of WSM and sensory integration processes at the level of motoneurons. Collectively, the findings contribute to our general understanding how moving animals integrate sensory information with dynamically changing temporal structure. PMID:26909184

  6. Proprioceptive Actuation Design for Dynamic Legged locomotion

    NASA Astrophysics Data System (ADS)

    Kim, Sangbae; Wensing, Patrick; Biomimetic Robotics Lab Team

    Designing an actuator system for highly-dynamic legged locomotion exhibited by animals has been one of the grand challenges in robotics research. Conventional actuators designed for manufacturing applications have difficulty satisfying challenging requirements for high-speed locomotion, such as the need for high torque density and the ability to manage dynamic physical interactions. It is critical to introduce a new actuator design paradigm and provide guidelines for its incorporation in future mobile robots for research and industry. To this end, we suggest a paradigm called proprioceptive actuation, which enables highly- dynamic operation in legged machines. Proprioceptive actuation uses collocated force control at the joints to effectively control contact interactions at the feet under dynamic conditions. In the realm of legged machines, this paradigm provides a unique combination of high torque density, high-bandwidth force control, and the ability to mitigate impacts through backdrivability. Results show that the proposed design provides an impact mitigation factor that is comparable to other quadruped designs with series springs to handle impact. The paradigm is shown to enable the MIT Cheetah to manage the application of contact forces during dynamic bounding, with results given down to contact times of 85ms and peak forces over 450N. As a result, the MIT Cheetah achieves high-speed 3D running up to 13mph and jumping over an 18-inch high obstacle. The project is sponsored by DARPA M3 program.

  7. Age-related differences in EEG beta activity during an assessment of ankle proprioception.

    PubMed

    Toledo, Diana R; Barela, José A; Manzano, Gilberto M; Kohn, André F

    2016-05-27

    The aim of this work was to compare cortical beta oscillatory activity between young (YA) and older (OA) adults during the assessment of ankle proprioception. We analyzed the response time (RT) to kinesthetic perception and beta event-related desynchronization/synchronization (ERD/ERS) in response to passive ankle movement applied at a slow speed, 0.5°/s. The relationship between ERD/ERS and RT was investigated by classifying the signals into fast-, medium-, and slow-RT. The results showed a temporal relationship between beta oscillation changes and RT for both groups, i.e., earlier ERD and ERS were obtained for trials with faster response time. ERD was larger and delayed in OA compared to the YA, and beta ERS was present only for OA. These findings suggest that a less efficient proprioceptive signaling reaching the brain of OA requires a higher level of brain processing and hence the differences in ERD potentials between YA and OA. Furthermore, the occurrence of ERS in OA might represent a compensatory strategy of active cortical resetting for adequate sensorimotor behavior due to the age-related reduced peripheral input and neuromuscular impairments. Altered balance between excitatory and inhibitory intracortical activity in older adults presumably explains the changes in beta oscillations. PMID:27085535

  8. Refining rehabilitation with proprioception training: expediting return to play.

    PubMed

    Laskowski, E R; Newcomer-Aney, K; Smith, J

    1997-10-01

    Although definitions of proprioception sense of joint position may vary, its importance in preventing and rehabilitating athletic injury remains constant: Restoring it after injury allows the body to maintain stability and orientation during static and dynamic activities. Any type of joint injury can interrupt position sense. Proprioceptive programs need to be tailored to the individual patient, but exercises can include balance training, closed-kinetic-chain exercises such as the leg press or single-leg hops, back-strengtheners, and quadruped stabilization. Sport-specific training is also crucial in regaining proprioception; an example is defensive slide drills in basketball.

  9. Motor output variability, deafferentation, and putative deficits in kinesthetic reafference in Parkinson’s disease

    PubMed Central

    Torres, Elizabeth B.; Cole, Jonathan; Poizner, Howard

    2014-01-01

    Parkinson’s disease (PD) is a neurodegenerative disorder defined by motor impairments that include rigidity, systemic slowdown of movement (bradykinesia), postural problems, and tremor. While the progressive decline in motor output functions is well documented, less understood are impairments linked to the continuous kinesthetic sensation emerging from the flow of motions. There is growing evidence in recent years that kinesthetic problems are also part of the symptoms of PD, but objective methods to readily quantify continuously unfolding motions across different contexts have been lacking. Here we present evidence from a deafferented subject (IW) and a new statistical platform that enables new analyses of motor output variability measured as a continuous flow of kinesthetic reafferent input. Systematic increasing similarities between the patterns of motor output variability in IW and the participants with increasing degrees of PD severity suggest potential deficits in kinesthetic sensing in PD. We propose that these deficits may result from persistent, noisy, and random motor patterns as the disorder progresses. The stochastic signatures from the unfolding motions revealed levels of noise in the motor output fluctuations of these patients bound to decrease the kinesthetic signal’s bandwidth. The results are interpreted in light of the concept of kinesthetic reafference ( Von Holst and Mittelstaedt, 1950). In this context, noisy motor output variability from voluntary movements in PD leads to a returning stream of noisy afference caused, in turn, by those faulty movements themselves. Faulty efferent output re-enters the CNS as corrupted sensory motor input. We find here that severity level in PD leads to the persistence of such patterns, thus bringing the statistical signatures of the subjects with PD systematically closer to those of the subject without proprioception. PMID:25374524

  10. The role of proprioception and neuromuscular stability in carpal instabilities.

    PubMed

    Hagert, E; Lluch, A; Rein, S

    2016-01-01

    Carpal stability has traditionally been defined as dependent on the articular congruity of joint surfaces, the static stability maintained by intact ligaments, and the dynamic stability caused by muscle contractions resulting in a compression of joint surfaces. In the past decade, a fourth factor in carpal stability has been proposed, involving the neuromuscular and proprioceptive control of joints. The proprioception of the wrist originates from afferent signals elicited by sensory end organs (mechanoreceptors) in ligaments and joint capsules that elicit spinal reflexes for immediate joint stability, as well as higher order neuromuscular influx to the cerebellum and sensorimotor cortices for planning and executing joint control. The aim of this review is to provide an understanding of the role of proprioception and neuromuscular control in carpal instabilities by delineating the sensory innervation and the neuromuscular control of the carpus, as well as descriptions of clinical applications of proprioception in carpal instabilities. PMID:26115684

  11. Untangling visual and proprioceptive contributions to hand localisation over time.

    PubMed

    Bellan, Valeria; Gilpin, Helen R; Stanton, Tasha R; Newport, Roger; Gallace, Alberto; Moseley, G Lorimer

    2015-06-01

    Previous studies showed that self-localisation ability involves both vision and proprioception, integrated into a single percept, with the tendency to rely more heavily on visual than proprioceptive cues. Despite the increasing evidence for the importance of vision in localising the hands, the time course of the interaction between vision and proprioception during visual occlusion remains unclear. In particular, we investigated how the brain weighs visual and proprioceptive information in hand localisation over time when the visual cues do not reflect the real position of the hand. We tested three hypotheses: Self-localisations are less accurate when vision and proprioception are incongruent; under the same conditions of incongruence, people first rely on vision and gradually revert to proprioception; if vision is removed immediately prior to hand localisation, accuracy increases. Sixteen participants viewed a video of their hands, under three conditions each undertaken with eyes open or closed: Incongruent conditions (right hand movement seen: inward, right hand real movement: outward), Congruent conditions (movement seen congruent to real movement). The right hand was then hidden from view and participants performed a localisation task whereby a moving vertical arrow was stopped when aligned with the felt position of their middle finger. A second experiment used identical methodology, but with the direction of the arrow switched. Our data showed that, in the Incongruent conditions (both with eyes open and closed), participants perceived their right hand close to its last seen position. Over time, the perceived position of the hand shifted towards the physical position. Closing the eyes before the localisation task increased the accuracy in the Incongruent condition. Crucially, Experiment 2 confirmed the findings and showed that the direction of arrow movement had no effect on hand localisation. Our hypotheses were supported: When vision and proprioception were

  12. Prism adaptation changes the subjective proprioceptive localization of the hands.

    PubMed

    Scarpina, Federica; Van der Stigchel, Stefan; Nijboer, Tanja Cornelia Wilhelmina; Dijkerman, Hendrik Christiaan

    2015-03-01

    Prism adaptation involves a proprioceptive, a visual and a motor component. As the existing paradigms are not able to distinguish between these three components, the contribution of the proprioceptive component remains unclear. In the current study, a proprioceptive judgement task, in the absence of motor responses, was used to investigate how prism adaptation would specifically influences the felt position of the hands in healthy participants. The task was administered before and after adaptation to left and right displacing prisms using either the left or the right hand during the adaptation procedure. The results appeared to suggest that the prisms induced a drift in the felt position of the hands, although the after-effect depended on the combination of the pointing hand and the visual deviation induced by prisms. The results are interpreted as in line with the hypothesis of an asymmetrical neural architecture of somatosensory processing. Moreover, the passive proprioception of the hand position revealed different effects of proprioceptive re-alignment compared to active pointing straight ahead: different mechanisms about how visuo-proprioceptive discrepancy is resolved were hypothesized.

  13. EDITORIAL: Slow light Slow light

    NASA Astrophysics Data System (ADS)

    Boyd, Robert; Hess, Ortwin; Denz, Cornelia; Paspalakis, Emmanuel

    2010-10-01

    Research into slow light began theoretically in 1880 with the paper [1] of H A Lorentz, who is best known for his work on relativity and the speed of light. Experimental work started some 60 years later with the work of S L McCall and E L Hahn [2] who explored non-linear self-induced transparency in ruby. This field of research has burgeoned in the last 10 years, starting with the work of L Vestergaard Hau and coworkers on slow light via electromagnetically induced transparency in a Bose-Einstein condensate [3]. Many groups are now able to slow light down to a few metres per second or even stop the motion of light entirely [4]. Today, slow light - or more often `slow and fast light' - has become its own vibrant field with a strongly increasing number of publications. In broad scope, slow light research can be categorized in terms of the sort of physical mechanism used to slow down the light. One sort of slow light makes use of material dispersion. This dispersion can be the natural dispersion of the ordinary refractive index or can be the frequency dependence of some nonlinear optical process, such as electromagnetically induced transparency, coherent population oscillations, stimulated light scattering, or four-wave mixing processes. The second sort of slow light makes use of the wavelength dependence of artificially structured materials, such as photonic crystals, optical waveguides, and collections of microresonators. Material systems in which slow light has been observed include metal vapours, rare-earth-doped materials, Raman and Brillioun gain media, photonic crystals, microresonators and, more recently, metamaterials. A common feature of all of these schemes is the presence of a sharp single resonance or multiple resonances produced by an atomic transition, a resonance in a photonic structure, or in a nonlinear optical process. Current applications of slow light include a series of attractive topics in optical information processing, such as optical data

  14. Reactive Neurogenesis and Down-Regulation of the Potassium-Chloride Cotransporter KCC2 in the Cochlear Nuclei after Cochlear Deafferentation.

    PubMed

    Tighilet, Brahim; Dutheil, Sophie; Siponen, Marina I; Noreña, Arnaud J

    2016-01-01

    While many studies have been devoted to investigating the homeostatic plasticity triggered by cochlear hearing loss, the cellular and molecular mechanisms involved in these central changes remain elusive. In the present study, we investigated the possibility of reactive neurogenesis after unilateral cochlear nerve section in the cochlear nucleus (CN) of cats. We found a strong cell proliferation in all the CN sub-divisions ipsilateral to the lesion. Most of the newly generated cells survive up to 1 month after cochlear deafferentation in all cochlear nuclei (except the dorsal CN) and give rise to a variety of cell types, i.e., microglial cells, astrocytes, and neurons. Interestingly, many of the newborn neurons had an inhibitory (GABAergic) phenotype. This result is intriguing since sensory deafferentation is usually accompanied by enhanced excitation, consistent with a reduction in central inhibition. The membrane potential effect of GABA depends, however, on the intra-cellular chloride concentration, which is maintained at low levels in adults by the potassium chloride co-transporter KCC2. The KCC2 density on the plasma membrane of neurons was then assessed after cochlear deafferentation in the cochlear nuclei ipsilateral and contralateral to the lesion. Cochlear deafferentation is accompanied by a strong down-regulation of KCC2 ipsilateral to the lesion at 3 and 30 days post-lesion. This study suggests that reactive neurogenesis and down-regulation of KCC2 is part of the vast repertoire involved in homeostatic plasticity triggered by hearing loss. These central changes may also play a role in the generation of tinnitus and hyperacusis. PMID:27630564

  15. Reactive Neurogenesis and Down-Regulation of the Potassium-Chloride Cotransporter KCC2 in the Cochlear Nuclei after Cochlear Deafferentation

    PubMed Central

    Tighilet, Brahim; Dutheil, Sophie; Siponen, Marina I.; Noreña, Arnaud J.

    2016-01-01

    While many studies have been devoted to investigating the homeostatic plasticity triggered by cochlear hearing loss, the cellular and molecular mechanisms involved in these central changes remain elusive. In the present study, we investigated the possibility of reactive neurogenesis after unilateral cochlear nerve section in the cochlear nucleus (CN) of cats. We found a strong cell proliferation in all the CN sub-divisions ipsilateral to the lesion. Most of the newly generated cells survive up to 1 month after cochlear deafferentation in all cochlear nuclei (except the dorsal CN) and give rise to a variety of cell types, i.e., microglial cells, astrocytes, and neurons. Interestingly, many of the newborn neurons had an inhibitory (GABAergic) phenotype. This result is intriguing since sensory deafferentation is usually accompanied by enhanced excitation, consistent with a reduction in central inhibition. The membrane potential effect of GABA depends, however, on the intra-cellular chloride concentration, which is maintained at low levels in adults by the potassium chloride co-transporter KCC2. The KCC2 density on the plasma membrane of neurons was then assessed after cochlear deafferentation in the cochlear nuclei ipsilateral and contralateral to the lesion. Cochlear deafferentation is accompanied by a strong down-regulation of KCC2 ipsilateral to the lesion at 3 and 30 days post-lesion. This study suggests that reactive neurogenesis and down-regulation of KCC2 is part of the vast repertoire involved in homeostatic plasticity triggered by hearing loss. These central changes may also play a role in the generation of tinnitus and hyperacusis. PMID:27630564

  16. Reactive Neurogenesis and Down-Regulation of the Potassium-Chloride Cotransporter KCC2 in the Cochlear Nuclei after Cochlear Deafferentation

    PubMed Central

    Tighilet, Brahim; Dutheil, Sophie; Siponen, Marina I.; Noreña, Arnaud J.

    2016-01-01

    While many studies have been devoted to investigating the homeostatic plasticity triggered by cochlear hearing loss, the cellular and molecular mechanisms involved in these central changes remain elusive. In the present study, we investigated the possibility of reactive neurogenesis after unilateral cochlear nerve section in the cochlear nucleus (CN) of cats. We found a strong cell proliferation in all the CN sub-divisions ipsilateral to the lesion. Most of the newly generated cells survive up to 1 month after cochlear deafferentation in all cochlear nuclei (except the dorsal CN) and give rise to a variety of cell types, i.e., microglial cells, astrocytes, and neurons. Interestingly, many of the newborn neurons had an inhibitory (GABAergic) phenotype. This result is intriguing since sensory deafferentation is usually accompanied by enhanced excitation, consistent with a reduction in central inhibition. The membrane potential effect of GABA depends, however, on the intra-cellular chloride concentration, which is maintained at low levels in adults by the potassium chloride co-transporter KCC2. The KCC2 density on the plasma membrane of neurons was then assessed after cochlear deafferentation in the cochlear nuclei ipsilateral and contralateral to the lesion. Cochlear deafferentation is accompanied by a strong down-regulation of KCC2 ipsilateral to the lesion at 3 and 30 days post-lesion. This study suggests that reactive neurogenesis and down-regulation of KCC2 is part of the vast repertoire involved in homeostatic plasticity triggered by hearing loss. These central changes may also play a role in the generation of tinnitus and hyperacusis.

  17. Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants.

    PubMed

    Bastien, Renaud; Bohr, Tomas; Moulia, Bruno; Douady, Stéphane

    2013-01-01

    Gravitropism, the slow reorientation of plant growth in response to gravity, is a key determinant of the form and posture of land plants. Shoot gravitropism is triggered when statocysts sense the local angle of the growing organ relative to the gravitational field. Lateral transport of the hormone auxin to the lower side is then enhanced, resulting in differential gene expression and cell elongation causing the organ to bend. However, little is known about the dynamics, regulation, and diversity of the entire bending and straightening process. Here, we modeled the bending and straightening of a rod-like organ and compared it with the gravitropism kinematics of different organs from 11 angiosperms. We show that gravitropic straightening shares common traits across species, organs, and orders of magnitude. The minimal dynamic model accounting for these traits is not the widely cited gravisensing law but one that also takes into account the sensing of local curvature, what we describe here as a graviproprioceptive law. In our model, the entire dynamics of the bending/straightening response is described by a single dimensionless "bending number" B that reflects the ratio between graviceptive and proprioceptive sensitivities. The parameter B defines both the final shape of the organ at equilibrium and the timing of curving and straightening. B can be estimated from simple experiments, and the model can then explain most of the diversity observed in experiments. Proprioceptive sensing is thus as important as gravisensing in gravitropic control, and the B ratio can be measured as phenotype in genetic studies.

  18. Identified proprioceptive afferents and motor rhythm entrainment in the crayfish walking system.

    PubMed

    Elson, R C; Sillar, K T; Bush, B M

    1992-03-01

    1. In crayfish, Pacifastacus leniusculus, remotion of a walking leg stretches the thoraco-coxal (TC) muscle receptor organ (TCMRO), located at the leg's articulation with the thorax. In vitro, alternate stretch and release of the fourth leg's TCMRO entrained the centrally generated rhythmic motor output to that leg, with the remotor phase of the rhythm entraining to TCMRO stretch, the promoter phase to release. This coordination of motor bursts to afferent input corresponds to that of active, rhythmic movements in vivo. 2. Entrainment was rapid in onset (stable coordination resulting within the first or second stimulus cycle) and was relatively phase-constant (whatever the stimulus frequency, during 1:1 entrainment, remotor bursts began near the onset of stretch and promotor bursts began near the onset of release). Outside the range of 1:1 entrainment, 2:1, 1:2, and 1:3 coordination ratios (rhythm:stimulus) were encountered. Resetting by phasic stimulation of the TCMRO was complete and probabilistic: effective stimuli triggered rapid transitions between the two burst phases. 3. The TCMRO is innervated by two afferents, the nonspiking S and T fibers, which generate graded depolarizing receptor potentials in response to stretch. During proprioceptive entrainment, the more phasic T fiber depolarized and hyperpolarized more rapidly or in advance of the more tonic S fiber. These receptor potentials were modified differently in the two afferents by interaction with central synaptic inputs that were phase-locked to the entrained motor rhythm. 4. Injecting slow sinusoidal current into either afferent alone could entrain motor rhythms: promoter phase bursts were entrained to depolarization of the S fiber or hyperpolarization of the T fiber, whereas the converse response was obtained for remotor phase bursts. 5. During proprioceptive entrainment, tonic hyperpolarization of the S fiber weakened entrained promotor bursts and allowed remotor burst durations to increase

  19. Neglect and extinction in kinesthesia and thesesthesia: understanding proprioceptive inattention.

    PubMed

    Karageorgiou, Elissaios

    2016-01-01

    This paper describes a new observation of neglect and extinction of kinesthesia and thesesthesia (movement and position imperception), jointly reflecting proprioceptive inattention, in a series of patients with parietal lesions. A prototypical case is discussed in detail and unaddressed aspects of proprioceptive inattention are discussed through findings from four additional cases. Thesesthetic and kinesthetic extinction were tested through simultaneous antidromic vertical displacement of index fingers, while having patients report on finger proprioceptive perception with eyes closed. Patients had variable degrees of proprioceptive inattention affecting a specific limb, but without pallesthetic inattention or somatoagnosia, whereas symptoms often resolved with visual feedback or active limb movements. Findings support that kinesthesia and thesesthesia (a) are subserved by near-identical brain networks, (b) relate more to tactile perception than pallesthesia in higher order cortical areas, and (c) have a somatotopic cortical organization even in association brain areas. Furthermore, proprioceptive extinction and neglect involve (i) "attention network" structures, (ii) either hemisphere, (iii) gray or subcortical white matter damage, (iv) defective vigilance mechanisms possibly through premature habituation of spatiotemporally saturated neural capacitor circuits, and (v) are not the result of somatoagnosia, while (vi) their resolution is observed through reafferent motor-sensory or visual feedback.

  20. Wrist proprioceptive acuity: A comprehensive robot-aided assessment.

    PubMed

    Cappello, Leonardo; Contu, Sara; Konczak, Juergen; Masia, Lorenzo

    2015-08-01

    Proprioception is the sense of the body awareness. Proprioceptive deficits represent frequent consequences of several neurological conditions like stroke, Parkinson's disease and others. The assessment of such somatosensory function is crucial, although the available clinical tests are not sensitive enough. The human wrist is a crucial joint for many activities of daily living and to address the lack of its characterization in terms of proprioceptive acuity the authors in previous studies proposed a novel method that combined the use of a 3-DoF robot and a threshold haunting paradigm. Further experiments were performed to characterize the proprioceptive acuity of the dominant wrist for adduction, extension, pronation and supination by using a 2-alternative-forced-choice test. The acuity thresholds obtained from six subjects (mean values ± standard deviation of 1.65±0.39 for extension, 1.13±0.34 for adduction, 1.90±0.58 for pronation and 1.70±0.30 for supination) were finally combined with the ones harvested in the previous studies for flexion and abduction in order to build the first comprehensive database of human wrist proprioceptive acuity.

  1. The Effects of Complete Vestibular Deafferentation on Spatial Memory and the Hippocampus in the Rat: The Dunedin Experience.

    PubMed

    Smith, Paul F; Darlington, Cynthia L; Zhen, Yiwen

    2015-01-01

    Our studies conducted over the last 14 years have demonstrated that a complete bilateral vestibular deafferentation (BVD) in rats results in spatial memory deficits in a variety of behavioural tasks, such as the radial arm maze, the foraging task and the spatial T maze, as well as deficits in other tasks such as the five-choice serial reaction time task (5-CSRT task) and object recognition memory task. These deficits persist long after the BVD, and are not simply attributable to ataxia, anxiety, hearing loss or hyperactivity. In tasks such as the foraging task, the spatial memory deficits are evident in darkness when vision is not required to perform the task. The deficits in the radial arm maze, the foraging task and the spatial T maze, in particular, suggest hippocampal dysfunction following BVD, and this is supported by the finding that both hippocampal place cells and theta rhythm are dysfunctional in BVD rats. Now that it is clear that the hippocampus is adversely affected by BVD, the next challenge is to determine what vestibular information is transmitted to it and how that information is used by the hippocampus and the other brain structures with which it interacts.

  2. Piezo2 is the principal mechanotransduction channel for proprioception

    PubMed Central

    Woo, Seung-Hyun; Lukacs, Viktor; de Nooij, Joriene C.; Zaytseva, Dasha; Criddle, Connor R.; Francisco, Allain; Jessell, Thomas M.; Wilkinson, Katherine A.; Patapoutian, Ardem

    2015-01-01

    Proprioception, the perception of body and limb position, is mediated by proprioceptors, specialized mechanosensory neurons that convey information about the stretch and tension experienced by muscles, tendons, skin, and joints. In mammals, the molecular identity of the stretch-sensitive channel that mediates proprioception is unknown. Here we show that the mechanically activated (MA) nonselective cation channel Piezo2 is expressed in sensory endings of proprioceptors innervating muscle spindles and Golgi tendon organs in mice. Two independent mouse lines that lack Piezo2 in proprioceptive neurons show severely uncoordinated body movements and abnormal limb positions. Moreover, the mechanosensitivity of Pvalb+ neurons that predominantly mark proprioceptors are dependent on Piezo2 in vitro, and the stretch-induced firing of proprioceptors in muscle-nerve recordings is dramatically reduced in Piezo2-deficient mice. Together, our results indicate that Piezo2 is the major mechanotransducer of mammalian proprioceptors. PMID:26551544

  3. Piezo2 is the principal mechanotransduction channel for proprioception.

    PubMed

    Woo, Seung-Hyun; Lukacs, Viktor; de Nooij, Joriene C; Zaytseva, Dasha; Criddle, Connor R; Francisco, Allain; Jessell, Thomas M; Wilkinson, Katherine A; Patapoutian, Ardem

    2015-12-01

    Proprioception, the perception of body and limb position, is mediated by proprioceptors, specialized mechanosensory neurons that convey information about the stretch and tension experienced by muscles, tendons, skin and joints. In mammals, the molecular identity of the stretch-sensitive channel that mediates proprioception is unknown. We found that the mechanically activated nonselective cation channel Piezo2 was expressed in sensory endings of proprioceptors innervating muscle spindles and Golgi tendon organs in mice. Two independent mouse lines that lack Piezo2 in proprioceptive neurons showed severely uncoordinated body movements and abnormal limb positions. Moreover, the mechanosensitivity of parvalbumin-expressing neurons that predominantly mark proprioceptors was dependent on Piezo2 expression in vitro, and the stretch-induced firing of proprioceptors in muscle-nerve recordings was markedly reduced in Piezo2-deficient mice. Together, our results indicate that Piezo2 is the major mechanotransducer of mammalian proprioceptors. PMID:26551544

  4. Interactions between tactile and proprioceptive representations in haptics.

    PubMed

    Rincon-Gonzalez, L; Naufel, S N; Santos, V J; Helms Tillery, S

    2012-01-01

    Neuroprosthetic limbs, regardless of their sophisticated motor control, require sensory feedback to viably interact with the environment. Toward that aim, the authors examined interrelationships between tactile and proprioceptive sensations. Through human psychophysics experiments, they evaluated error patterns of subjects estimating hand location in a horizontal 2-dimensional workspace under 3 tactile conditions. While tactile cues did not significantly affect the structure of the pattern of errors, touching the workspace reduced estimation errors. During neurophysiological experiments, a macaque grasped textured objects using 2 hand postures. Sensory coding showed dependence on both roughness of the manipulandum and posture. In summary, the authors suggest that tactile sensations underlying haptics are processed in a stable spatial reference frame provided by a proprioceptive system, and that tactile and proprioceptive inputs can be encoded simultaneously by individual cells. Such insights will be useful for providing stable, adaptive sensory feedback for neuroprosthetics.

  5. Proprioceptive target matching asymmetries in left-handed individuals.

    PubMed

    Goble, Daniel J; Noble, Brittany C; Brown, Susan H

    2009-08-01

    In right-handers, the ability to reproduce proprioceptive targets has been shown to be asymmetric, favoring the non-preferred left arm. The present study sought to determine whether a similar arm/hemisphere asymmetry exists for left-handers. Ten strong left-handed adults used the left or right arm to perform proprioceptive target matching tasks that varied in processing demands (i.e., need for memory, interhemispheric transfer) and target amplitude (20, 40 degrees). Similar to right-handers, left-handed individuals had smaller total errors when matching with the non-preferred arm. This asymmetry was greatest in conditions with increased processing demands and larger amplitude targets. These results provide the first evidence to date of right arm/left hemisphere dominance for proprioceptive target matching in left-handers that is the "mirror image" of right-handers.

  6. Slow Antihydrogen

    SciTech Connect

    Gabrielse, G.; Speck, A.; Storry, C.H.; Le Sage, D.; Guise, N.; Larochelle, P.C.; Grzonka, D.; Oelert, W.; Schepers, G.; Sefzick, T.; Pittner, H.; Herrmann, M.; Walz, J.; Haensch, T.W.

    2004-10-20

    Slow antihydrogen is now produced by two different production methods. In Method I, large numbers of H atoms are produced during positron-cooling of antiprotons within a nested Penning trap. In a just-demonstrated Method II, lasers control the production of antihydrogen atoms via charge exchange collisions. Field ionization detection makes it possible to probe the internal structure of the antihydrogen atoms being produced - most recently revealing atoms that are too tightly bound to be well described by the guiding center atom approximation. The speed of antihydrogen atoms has recently been measured for the first time. After the requested overview, the recent developments are surveyed.

  7. Proprioceptive rehabilitation of upper limb dysfunction in movement disorders: a clinical perspective.

    PubMed

    Abbruzzese, Giovanni; Trompetto, Carlo; Mori, Laura; Pelosin, Elisa

    2014-01-01

    Movement disorders (MDs) are frequently associated with sensory abnormalities. In particular, proprioceptive deficits have been largely documented in both hypokinetic (Parkinson's disease) and hyperkinetic conditions (dystonia), suggesting a possible role in their pathophysiology. Proprioceptive feedback is a fundamental component of sensorimotor integration allowing effective planning and execution of voluntary movements. Rehabilitation has become an essential element in the management of patients with MDs, and there is a strong rationale to include proprioceptive training in rehabilitation protocols focused on mobility problems of the upper limbs. Proprioceptive training is aimed at improving the integration of proprioceptive signals using "task-intrinsic" or "augmented feedback." This perspective article reviews the available evidence on the effects of proprioceptive stimulation in improving upper limb mobility in patients with MDs and highlights the emerging innovative approaches targeted to maximizing the benefits of exercise by means of enhanced proprioception.

  8. Proprioceptive Rehabilitation of Upper Limb Dysfunction in Movement Disorders: A Clinical Perspective

    PubMed Central

    Abbruzzese, Giovanni; Trompetto, Carlo; Mori, Laura; Pelosin, Elisa

    2014-01-01

    Movement disorders (MDs) are frequently associated with sensory abnormalities. In particular, proprioceptive deficits have been largely documented in both hypokinetic (Parkinson’s disease) and hyperkinetic conditions (dystonia), suggesting a possible role in their pathophysiology. Proprioceptive feedback is a fundamental component of sensorimotor integration allowing effective planning and execution of voluntary movements. Rehabilitation has become an essential element in the management of patients with MDs, and there is a strong rationale to include proprioceptive training in rehabilitation protocols focused on mobility problems of the upper limbs. Proprioceptive training is aimed at improving the integration of proprioceptive signals using “task-intrinsic” or “augmented feedback.” This perspective article reviews the available evidence on the effects of proprioceptive stimulation in improving upper limb mobility in patients with MDs and highlights the emerging innovative approaches targeted to maximizing the benefits of exercise by means of enhanced proprioception. PMID:25505402

  9. The Role of Ankle Proprioception for Balance Control in relation to Sports Performance and Injury

    PubMed Central

    Han, Jia; Anson, Judith; Waddington, Gordon; Adams, Roger; Liu, Yu

    2015-01-01

    Balance control improvement is one of the most important goals in sports and exercise. Better balance is strongly positively associated with enhanced athletic performance and negatively associated with lower limb sports injuries. Proprioception plays an essential role in balance control, and ankle proprioception is arguably the most important. This paper reviews ankle proprioception and explores synergies with balance control, specifically in a sporting context. Central processing of ankle proprioceptive information, along with other sensory information, enables integration for balance control. When assessing ankle proprioception, the most generalizable findings arise from methods that are ecologically valid, allow proprioceptive signals to be integrated with general vision in the central nervous system, and reflect the signal-in-noise nature of central processing. Ankle proprioceptive intervention concepts driven by such a central processing theory are further proposed and discussed for the improvement of balance control in sport. PMID:26583139

  10. The Role of Ankle Proprioception for Balance Control in relation to Sports Performance and Injury.

    PubMed

    Han, Jia; Anson, Judith; Waddington, Gordon; Adams, Roger; Liu, Yu

    2015-01-01

    Balance control improvement is one of the most important goals in sports and exercise. Better balance is strongly positively associated with enhanced athletic performance and negatively associated with lower limb sports injuries. Proprioception plays an essential role in balance control, and ankle proprioception is arguably the most important. This paper reviews ankle proprioception and explores synergies with balance control, specifically in a sporting context. Central processing of ankle proprioceptive information, along with other sensory information, enables integration for balance control. When assessing ankle proprioception, the most generalizable findings arise from methods that are ecologically valid, allow proprioceptive signals to be integrated with general vision in the central nervous system, and reflect the signal-in-noise nature of central processing. Ankle proprioceptive intervention concepts driven by such a central processing theory are further proposed and discussed for the improvement of balance control in sport.

  11. Tentonin 3/TMEM150c Confers Distinct Mechanosensitive Currents in Dorsal-Root Ganglion Neurons with Proprioceptive Function.

    PubMed

    Hong, Gyu-Sang; Lee, Byeongjun; Wee, Jungwon; Chun, Hyeyeon; Kim, Hyungsup; Jung, Jooyoung; Cha, Joo Young; Riew, Tae-Ryong; Kim, Gyu Hyun; Kim, In-Beom; Oh, Uhtaek

    2016-07-01

    Touch sensation or proprioception requires the transduction of mechanical stimuli into electrical signals by mechanoreceptors in the periphery. These mechanoreceptors are equipped with various transducer channels. Although Piezo1 and 2 are mechanically activated (MA) channels with rapid inactivation, MA molecules with other inactivation kinetics have not been identified. Here we report that heterologously expressed Tentonin3 (TTN3)/TMEM150C is activated by mechanical stimuli with distinctly slow inactivation kinetics. Genetic ablation of Ttn3/Tmem150c markedly reduced slowly adapting neurons in dorsal-root ganglion neurons. The MA TTN3 currents were inhibited by known blockers of mechanosensitive ion channels. Moreover, TTN3 was localized in muscle spindle afferents. Ttn3-deficient mice exhibited the loss of coordinated movements and abnormal gait. Thus, TTN3 appears to be a component of a mechanosensitive channel with a slow inactivation rate and contributes to motor coordination. Identification of this gene advances our understanding of the various types of mechanosensations, including proprioception. PMID:27321926

  12. Proprioceptive precision is impaired in Ehlers-Danlos syndrome.

    PubMed

    Clayton, Holly A; Jones, Stephanie A H; Henriques, Denise Y P

    2015-01-01

    It has been suggested that people with Ehlers-Danlos syndrome (EDS), or other similar connective tissue disorders, may have proprioceptive impairments, the reason for which is still unknown. We recently found that EDS patients were less precise than healthy controls when estimating their felt hand's position relative to visible peripheral reference locations, and that this deficit was positively correlated with the severity of joint hypermobility. We further explore proprioceptive abilities in EDS by having patients localize their non-dominant left hand at a greater number of workspace locations than in our previous study. Additionally, we explore the relationship between chronic pain and proprioceptive sensitivity. We found that, although patients were just as accurate as controls, they were not as precise. Patients showed twice as much scatter than controls at all locations, but the degree of scatter did not positively correlate with chronic pain scores. This further supports the idea that a proprioceptive impairment pertaining to precision is present in EDS, but may not relate to the magnitude of chronic pain.

  13. Proprioceptive recalibration arises slowly compared to reach adaptation.

    PubMed

    Zbib, Basel; Henriques, Denise Y P; Cressman, Erin K

    2016-08-01

    When subjects reach in a novel visuomotor environment (e.g. while viewing a cursor representing their hand that is rotated from their hand's actual position), they typically adjust their movements (i.e. bring the cursor to the target), thus reducing reaching errors. Additionally, research has shown that reaching with altered visual feedback of the hand results in sensory changes, such that proprioceptive estimates of hand position are shifted in the direction of the visual feedback experienced (Cressman and Henriques in J Neurophysiol 102:3505-3518, 2009). This study looked to establish the time course of these sensory changes. Additionally, the time courses of implicit sensory and motor changes were compared. Subjects reached to a single visual target while seeing a cursor that was either aligned with their hand position (50 trials) or rotated 30° clockwise relative to their hand (150 trials). Reach errors and proprioceptive estimates of felt hand position were assessed following the aligned reach training trials and at seven different times during the rotated reach training trials by having subjects reach to the target without visual feedback, and provide estimates of their hand relative to a visual reference marker, respectively. Results revealed a shift in proprioceptive estimates throughout the rotated reach training trials; however, significant sensory changes were not observed until after 70 trials. In contrast, results showed a greater change in reaches after a limited number of reach training trials with the rotated cursor. These findings suggest that proprioceptive recalibration arises more slowly than reach adaptation.

  14. PROPRIOCEPTION, BODY BALANCE AND FUNCTIONALITY IN INDIVIDUALS WITH ACL RECONSTRUCTION

    PubMed Central

    Furlanetto, Tássia Silveira; Peyré-Tartaruga, Leonardo Alexandre; do Pinho, Alexandre Severo; Bernardes, Emanuele da Silva; Zaro, Milton Antonio

    2016-01-01

    Objective : To evaluate and compare proprioception, body balance and knee functionality of individuals with or without unilateral anterior cruciate ligament (ACL) reconstruction. Methods : Forty individuals were divided in two groups: Experimental group, 20 individuals with ACL reconstruction at six months postoperative, and control group, 20 individuals with no history of lower limb pathologies. In the experimental group, we assessed lower limbs with reconstructed ACL and contralateral limb; in the control group the dominant and the non-dominant lower limbs were assessed. All subjects were submitted to joint position sense test to evaluate proprioception, postural control measure in single-limb, and step up and down (SUD) test for functional assessment. Results : There were no deficits in proprioception and postural control. In the SUD test, a 5% decrease in lift up force was found in reconstructed ACL lower limbs, however, a statistically not significant difference. The impact and step down force during the course of test were 30% greater in anatomic ACL than in control lower limbs. Conclusion : The individuals with ACL reconstruction at six months postoperative did not show changes in proprioception and postural control, but showed motor control changes, influencing knee functionality. Level of Evidence IV, Prognostic Studies. PMID:26981038

  15. Proprioceptive precision is impaired in Ehlers-Danlos syndrome.

    PubMed

    Clayton, Holly A; Jones, Stephanie A H; Henriques, Denise Y P

    2015-01-01

    It has been suggested that people with Ehlers-Danlos syndrome (EDS), or other similar connective tissue disorders, may have proprioceptive impairments, the reason for which is still unknown. We recently found that EDS patients were less precise than healthy controls when estimating their felt hand's position relative to visible peripheral reference locations, and that this deficit was positively correlated with the severity of joint hypermobility. We further explore proprioceptive abilities in EDS by having patients localize their non-dominant left hand at a greater number of workspace locations than in our previous study. Additionally, we explore the relationship between chronic pain and proprioceptive sensitivity. We found that, although patients were just as accurate as controls, they were not as precise. Patients showed twice as much scatter than controls at all locations, but the degree of scatter did not positively correlate with chronic pain scores. This further supports the idea that a proprioceptive impairment pertaining to precision is present in EDS, but may not relate to the magnitude of chronic pain. PMID:26180743

  16. Differences in Sensorimotor Processing of Visual and Proprioceptive Stimuli

    ERIC Educational Resources Information Center

    Kamen, Gary and Morris, Harold H.

    1988-01-01

    A paradox in studying sensory perception is that people often attend to a stimulus which provides the least optimal information. Usually, this is a visual stimulus. The study sought to lessen this reliance on vision by training subjects to respond to proprioceptive stimuli. Results are discussed. (Author/JL)

  17. Finger opening in an overarm throw is not triggered by proprioceptive feedback from elbow extension or wrist flexion.

    PubMed

    Hore, J; Ritchie, R; Watts, S

    1999-04-01

    Accuracy in an overarm throw requires great precision in the timing of finger opening. We tested the hypothesis that finger opening in an overarm throw is triggered by proprioceptive feedback from elbow extension or wrist flexion. The hypothesis was tested in two ways: first, by unexpectedly perturbing elbow extension or slowing wrist flexion and determining whether changes occurred in finger opening, and second, by measuring the latency from the start of these joint rotations to the start of finger opening. Subjects threw balls fast and accurately from a sitting or standing position while joint rotations were recorded with the search-coil technique. Elbow extension was unexpectedly blocked near the start of forward motion of the hand by a rope attached to the wrist that passed through a catch mechanism located behind the subject. In spite of a slowing or complete block of elbow extension, and in some cases a replacement of elbow extension by elbow flexion, finger opening always occurred and at the same latency as for normal throws. Wrist flexion was slowed in seven of eight subjects when subjects changed from throwing with a light ball (14 g, 70 mm diam.) to a heavy ball (210 g, 65 mm diam.). For the first throw with the heavy ball, this slowing was neither fully anticipated by the subject nor compensated for by the changed proprioceptive feedback associated with the slowing. Consequently, the timing of finger opening was unchanged and (to the surprise of the thrower) the ball went high. Furthermore, in unperturbed throws with tennis balls, the latency from onset of wrist flexion or elbow extension to onset of finger opening was too short for either to have triggered finger opening (across subjects means were 4 ms for wrist flexion and 21 ms for elbow extension). In additional analysis, no relation was found between the time of onset of earlier occurring rotations at the shoulder and the time of onset of finger opening. We concluded that, although a role for all

  18. Haptic interaction of touch and proprioception: implications for neuroprosthetics.

    PubMed

    Rincon-Gonzalez, Liliana; Warren, Jay P; Meller, David M; Tillery, Stephen Helms

    2011-10-01

    Somatosensation is divided into multiple discrete modalities that we think of separably: e.g., tactile, proprioceptive, and temperature sensation. However, in processes such as haptics,those modalities all interact. If one intended to artificially generate a sensation that could be used for stereognosis, for example, it would be crucial to understand these interactions. We are presently examining the relationship between tactile and proprioceptive modalities in this context. In this overview of some of our recent work, we show that signals that would normally be attributed to two of these systems separately, tactile contact and self-movement, interact both perceptually and physiologically in ways that complicate the understanding of haptic processing. In the first study described here, we show that a tactile illusion on the fingertips, the cutaneous rabbit effect, can be abolished by changing the posture of the fingers. We then discuss activity in primary somatosensory cortical neurons illustrating the interrelationship of tactile and postural signals. In this study, we used a robot-enhanced virtual environment to show that many neurons in primary somatosensory cortex with cutaneous receptive fields encode elements both of tactile contact and self-motion. We then show the results of studies examining the structure of the process which extracts the spatial location of the hand from proprioceptive signals. The structure of the spatial errors in these maps indicates that the proprioceptive-spatial map is stable but individually constructed.These seemingly disparate studies lead us to suggest that tactile sensation is encoded in a 2-D map, but one which undergoes continual dynamic modification by an underlying proprioceptive map. Understanding how the disparate signals that comprise the somatosensory system are processed to produce sensation is an important step in realizing the kind of seamless integration aspired to in neuroprosthetics. PMID:21984518

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

    PubMed

    Matsuo, Kiyoshi; Osada, Yoshiro; Ban, Ryokuya

    2013-02-01

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

  20. A comparison of assisted and unassisted proprioceptive neuromuscular facilitation techniques and static stretching.

    PubMed

    Maddigan, Meaghan E; Peach, Ashley A; Behm, David G

    2012-05-01

    A comparison of assisted and unassisted proprioceptive neuromuscular facilitation techniques and static stretching. J Strength Cond Res 26(5): 1238-1244, 2012-Proprioceptive neuromuscular facilitation (PNF) stretching often requires a partner. Straps are available allowing an individual to perform PNF stretching alone. It is not known if a strap provides similar improvements in the range of motion (ROM) as partner-assisted PNF or static stretching. The purpose of this study was to compare assisted and unassisted (with a strap) PNF stretching and static stretching. Hip joint ROM, reaction time (RT), and movement time (MT) were measured prestretching and poststretching. Thirteen recreationally active adults participated in this study. The participants were subjected to 5 different stretch interventions in a random order on separate days. Stretch conditions included unassisted PNF stretching using (a) isometric, (b) concentric, and (c) eccentric contractions with a stretch strap, (d) partner-assisted isometric PNF, and (e) static stretching. The RT, MT, dynamic, active, passive hip flexion angle, and angular velocity with dynamic hip flexion were measured before and after the intervention. The ROM improved (p < 0.05) 2.6, 2.7, and 5.4%, respectively, with dynamic, active static, and passive static ROM, but there was no significant difference between the stretching protocols. There was a main effect for time (p < 0.05) with all stretching conditions negatively impacting dynamic angular velocity (9.2%). Although there was no significant effect on RT, MT showed a negative main effect for time (p < 0.05) slowing 3.4%. In conclusion, it was found that all 3 forms of active stretching provided similar improvements in the ROM and poststretching performance decrements in MT and angular velocity. Thus, individuals can implement PNF stretching techniques with a partner or alone with a strap to improve ROM, but athletes should not use these techniques before important

  1. Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants

    PubMed Central

    Bastien, Renaud; Bohr, Tomas; Moulia, Bruno; Douady, Stéphane

    2013-01-01

    Gravitropism, the slow reorientation of plant growth in response to gravity, is a key determinant of the form and posture of land plants. Shoot gravitropism is triggered when statocysts sense the local angle of the growing organ relative to the gravitational field. Lateral transport of the hormone auxin to the lower side is then enhanced, resulting in differential gene expression and cell elongation causing the organ to bend. However, little is known about the dynamics, regulation, and diversity of the entire bending and straightening process. Here, we modeled the bending and straightening of a rod-like organ and compared it with the gravitropism kinematics of different organs from 11 angiosperms. We show that gravitropic straightening shares common traits across species, organs, and orders of magnitude. The minimal dynamic model accounting for these traits is not the widely cited gravisensing law but one that also takes into account the sensing of local curvature, what we describe here as a graviproprioceptive law. In our model, the entire dynamics of the bending/straightening response is described by a single dimensionless “bending number” B that reflects the ratio between graviceptive and proprioceptive sensitivities. The parameter B defines both the final shape of the organ at equilibrium and the timing of curving and straightening. B can be estimated from simple experiments, and the model can then explain most of the diversity observed in experiments. Proprioceptive sensing is thus as important as gravisensing in gravitropic control, and the B ratio can be measured as phenotype in genetic studies. PMID:23236182

  2. Slow Pseudotachylites

    NASA Astrophysics Data System (ADS)

    Pec, M.; Stunitz, H.; Heilbronner, R.

    2011-12-01

    Tectonic pseudotachylites as solidified, friction induced melts are believed to be the only unequivocal evidence for paleo-earthquakes. Earthquakes occur when fast slip (1 - 3 m/s) propagates on a localized failure plane and are always related with stress drops. The mechanical work expended, together with the rock composition and the efficiency of thermal dissipation, controls whether the temperature increase on a localized slip plane will be sufficient to induce fusion. We report the formation of pseudotachylites during steady-state plastic flow at slow bulk shear strain rates (~10^-3 to ~10^-5 /s corresponding to slip rates of ~10^-6 to ~10^-8 m/s) in experiments performed at high confining pressures (500 MPa) and temperatures (300°C) corresponding to a depth of ~15 km. Crushed granitioid rock (Verzasca gneiss), grain size ≤ 200 μm, with 0.2 wt% water added was placed between alumina forcing blocks pre-cut at 45°, weld-sealed in platinum jackets and deformed with a constant displacement rate in a solid medium deformation apparatus (modified Griggs rig). Microstructural observations show the development of a S-C-C' fabric with C' slip zones being the dominant feature. Strain hardening in the beginning of the experiment is accompanied with compaction which is achieved by closely spaced R1 shears pervasively cutting the whole gouge zone and containing fine-grained material (d < 100 nm). The peak strength is achieved at γ ~ 2 at shear stress levels of 1350-1450 MPa when compaction ceases. During further deformation, large local displacements (γ > 10) are localized in less densely spaced, ~10 μm thick C'-C slip zones which develop predominantly in feldspars and often contain micas. In TEM, they appear to have no porosity consisting of partly amorphous material and small crystalline fragments with the average grain size of 20 nm. After the peak strength, the samples weaken by ~20 MPa and continue deforming up to γ ~ 4 without any stress drops. Strain

  3. Proprioceptive gait and speed selection in a slender inertial swimmer

    NASA Astrophysics Data System (ADS)

    Argentina, Mederic; Gazzola, Mattia; Mahadevan, L.

    2014-11-01

    We study the dynamics of a slender inertial swimmer accounting for hydrodynamics, mechanics, muscle activity and sensory feedbacks. Our theory elucidates how elastic properties and proprioception contribute to selecting swimming speed and locomotion gait. Swimmers are shown to take advantage of resonance phenomena to enhance speed and efficiency. Furthermore, we demonstrate how a minimal proprioceptive model, in which the local muscle activation is function of body curvature, is sufficient to exploit hydro-mechanic properties and drive elastic instabilities associated with thrust production. Our results quantitatively agree with live fish experiments and provide a mechanistic basis for the relation U/L ~ f between the swimmer's speed U, length L and tail beat frequency f determined empirically by Bainbridge more than half a century ago.

  4. Proprioceptive-Visual Integration and Embodied Cognition: A Developmental Perspective.

    PubMed

    Manoel, Edison de J; Viana Felicio, Pedro Fernando; Makida-Dionísio, Cristiane; Nascimento Soares, Rafael Do; Freitas, Alessandro; Gimenez, Roberto

    2016-10-01

    The present study addressed whether a spatial matching task relying on inter-sensory judgments might be influenced by the transition between egocentric and decentered mode of thinking. Thirty-six children aged 5, 7, or 9 years performed a paramedian correspondence task with conditions requiring inter-sensory integration (visual-proprioceptive) and a problem-solving task. The visual information was given through a mirror that perturbed the sensory judgments in the paramedian correspondence task. The results did not corroborate the hypotheses; nevertheless, the increasing importance of proprioception in the perceptual judgments for older children suggests that although younger children may be body centered (egocentric mode of thinking), older children seemed more able to use body to mediate their perceptual judgments.

  5. Proprioceptive-Visual Integration and Embodied Cognition: A Developmental Perspective.

    PubMed

    Manoel, Edison de J; Viana Felicio, Pedro Fernando; Makida-Dionísio, Cristiane; Nascimento Soares, Rafael Do; Freitas, Alessandro; Gimenez, Roberto

    2016-10-01

    The present study addressed whether a spatial matching task relying on inter-sensory judgments might be influenced by the transition between egocentric and decentered mode of thinking. Thirty-six children aged 5, 7, or 9 years performed a paramedian correspondence task with conditions requiring inter-sensory integration (visual-proprioceptive) and a problem-solving task. The visual information was given through a mirror that perturbed the sensory judgments in the paramedian correspondence task. The results did not corroborate the hypotheses; nevertheless, the increasing importance of proprioception in the perceptual judgments for older children suggests that although younger children may be body centered (egocentric mode of thinking), older children seemed more able to use body to mediate their perceptual judgments. PMID:27597780

  6. Proprioception and Tension Receptors in Crab Limbs: Student Laboratory Exercises

    PubMed Central

    Majeed, Zana R.; Titlow, Josh; Hartman, H. Bernard; Cooper, Robin

    2013-01-01

    The primary purpose of these procedures is to demonstrate for teaching and research purposes how to record the activity of living primary sensory neurons responsible for proprioception as they are detecting joint position and movement, and muscle tension. Electrical activity from crustacean proprioceptors and tension receptors is recorded by basic neurophysiological instrumentation, and a transducer is used to simultaneously measure force that is generated by stimulating a motor nerve. In addition, we demonstrate how to stain the neurons for a quick assessment of their anatomical arrangement or for permanent fixation. Staining reveals anatomical organization that is representative of chordotonal organs in most crustaceans. Comparing the tension nerve responses to the proprioceptive responses is an effective teaching tool in determining how these sensory neurons are defined functionally and how the anatomy is correlated to the function. Three staining techniques are presented allowing researchers and instructors to choose a method that is ideal for their laboratory. PMID:24192613

  7. Integration of vestibular and proprioceptive signals for spatial updating.

    PubMed

    Frissen, Ilja; Campos, Jennifer L; Souman, Jan L; Ernst, Marc O

    2011-07-01

    Spatial updating during self-motion typically involves the appropriate integration of both visual and non-visual cues, including vestibular and proprioceptive information. Here, we investigated how human observers combine these two non-visual cues during full-stride curvilinear walking. To obtain a continuous, real-time estimate of perceived position, observers were asked to continuously point toward a previously viewed target in the absence of vision. They did so while moving on a large circular treadmill under various movement conditions. Two conditions were designed to evaluate spatial updating when information was largely limited to either proprioceptive information (walking in place) or vestibular information (passive movement). A third condition evaluated updating when both sources of information were available (walking through space) and were either congruent or in conflict. During both the passive movement condition and while walking through space, the pattern of pointing behavior demonstrated evidence of accurate egocentric updating. In contrast, when walking in place, perceived self-motion was underestimated and participants always adjusted the pointer at a constant rate, irrespective of changes in the rate at which the participant moved relative to the target. The results are discussed in relation to the maximum likelihood estimation model of sensory integration. They show that when the two cues were congruent, estimates were combined, such that the variance of the adjustments was generally reduced. Results also suggest that when conflicts were introduced between the vestibular and proprioceptive cues, spatial updating was based on a weighted average of the two inputs. PMID:21590262

  8. Effect of ankle proprioceptive training on static body balance.

    PubMed

    Karakaya, Mehmet Gürhan; Rutbİl, Hilal; Akpinar, Ercan; Yildirim, Alİ; Karakaya, İlkİm Çitak

    2015-10-01

    [Purpose] This study aimed to investigate the effect of ankle proprioceptive training on static body balance. [Subjects and Methods] In this randomized-controlled, single-blind study, 59 university students (35 females, 24 males) were randomized into study (n=29) and control (n=30) groups. The study group received a foot and ankle proprioceptive exercise program including stretching, strengthening (plantar and dorsi-flexors, invertor and evertor muscles), and balance board exercises, each with 10 repetitions per session, 5 days a week, for a total of 10 sessions. The control group did not receive any intervention. Static body balance was evaluated by a kinesthetic ability trainer, which showed the balance index scores under both single foot and both feet conditions. This evaluation was repeated at the end of two weeks for both groups. [Results] Outcome measures of the groups were similar at the baseline. Balance index scores of both groups improved at the end of two weeks, and the study group had significantly lower index scores than those of the control group, indicating better balance. [Conclusion] Ankle proprioceptive training had positive effects on static body balance parameters in healthy individuals, and it is worth investigating the effects of this type of training in patients with balance disorders. PMID:26644697

  9. Effect of ankle proprioceptive training on static body balance.

    PubMed

    Karakaya, Mehmet Gürhan; Rutbİl, Hilal; Akpinar, Ercan; Yildirim, Alİ; Karakaya, İlkİm Çitak

    2015-10-01

    [Purpose] This study aimed to investigate the effect of ankle proprioceptive training on static body balance. [Subjects and Methods] In this randomized-controlled, single-blind study, 59 university students (35 females, 24 males) were randomized into study (n=29) and control (n=30) groups. The study group received a foot and ankle proprioceptive exercise program including stretching, strengthening (plantar and dorsi-flexors, invertor and evertor muscles), and balance board exercises, each with 10 repetitions per session, 5 days a week, for a total of 10 sessions. The control group did not receive any intervention. Static body balance was evaluated by a kinesthetic ability trainer, which showed the balance index scores under both single foot and both feet conditions. This evaluation was repeated at the end of two weeks for both groups. [Results] Outcome measures of the groups were similar at the baseline. Balance index scores of both groups improved at the end of two weeks, and the study group had significantly lower index scores than those of the control group, indicating better balance. [Conclusion] Ankle proprioceptive training had positive effects on static body balance parameters in healthy individuals, and it is worth investigating the effects of this type of training in patients with balance disorders.

  10. Intrathecal rimantadine induces motor, proprioceptive, and nociceptive blockades in rats.

    PubMed

    Tzeng, Jann-Inn; Wang, Jieh-Neng; Wang, Jhi-Joung; Chen, Yu-Wen; Hung, Ching-Hsia

    2016-04-01

    The purpose of the experiment was to evaluate the local anesthetic effect of rimantadine in spinal anesthesia. Rimantadine in a dose-dependent fashion was constructed after intrathecally injecting the rats with four different doses. The potency and duration of rimantadine were compared with that of the local anesthetic lidocaine at producing spinal motor, nociceptive, and proprioceptive blockades. We demonstrated that intrathecal rimantadine dose-dependently produced spinal motor, nociceptive, and proprioceptive blockades. On the 50% effective dose (ED50) basis, the ranks of potencies at inducing spinal motor, nociceptive, and proprioceptive blockades was lidocaine>rimantadine (P<0.01). Rimantadine exhibited more nociceptive block (ED50) than motor block (P<0.05). At equi-anesthetic doses (ED25, ED50, and ED75), the spinal block duration produced by rimantadine was longer than that produced by lidocaine (P<0.01). Furthermore, rimantadine (26.52μmol/kg) prolonged the nociceptive nerve block more than the motor block (P<0.001). Our preclinical data showed that rimantadine, with a more sensory-selective action over motor block, was less potent than lidocaine. Rimantadine produced longer duration in spinal anesthesia when compared with lidocaine.

  11. Effect of ankle proprioceptive training on static body balance

    PubMed Central

    Karakaya, Mehmet Gürhan; Rutbİl, Hİlal; Akpinar, Ercan; Yildirim, Alİ; Karakaya, İlkİm Çitak

    2015-01-01

    [Purpose] This study aimed to investigate the effect of ankle proprioceptive training on static body balance. [Subjects and Methods] In this randomized-controlled, single-blind study, 59 university students (35 females, 24 males) were randomized into study (n=29) and control (n=30) groups. The study group received a foot and ankle proprioceptive exercise program including stretching, strengthening (plantar and dorsi-flexors, invertor and evertor muscles), and balance board exercises, each with 10 repetitions per session, 5 days a week, for a total of 10 sessions. The control group did not receive any intervention. Static body balance was evaluated by a kinesthetic ability trainer, which showed the balance index scores under both single foot and both feet conditions. This evaluation was repeated at the end of two weeks for both groups. [Results] Outcome measures of the groups were similar at the baseline. Balance index scores of both groups improved at the end of two weeks, and the study group had significantly lower index scores than those of the control group, indicating better balance. [Conclusion] Ankle proprioceptive training had positive effects on static body balance parameters in healthy individuals, and it is worth investigating the effects of this type of training in patients with balance disorders. PMID:26644697

  12. Proprioception and palisade endings in extraocular eye muscles.

    PubMed

    Eberhorn, Andreas C; Horn, Anja K E; Fischer, Petra; Büttner-Ennever, Jean A

    2005-04-01

    Palisade endings occur only in extraocular muscles, and their function is unknown. They form a cuff of nerve terminals around the tips of muscle fibers. We describe here the advantages of using antibodies to a synaptosomal-associated protein (SNAP-25) to study properties of palisade endings in man, monkey, and rat. The stain can be combined readily with other immunofluorescence procedures, and results suggest that the synapses of palisade endings do not bind alpha-bungarotoxin (i.e., are not motor), nor do they contain substance P. These double-labeling data support the hypothesis that palisade endings are non-nociceptive sensory receptors, and could serve a proprioceptive function. With SNAP-25 immunolabeling, palisade endings were identified in the rat for the first time. Thus, palisade endings appear to be present in all vertebrate extraocular muscles studied to date. Their apparent universality, which contrasts with the more variable manifestation of extraocular muscle spindles and Golgi tendon organs, would be expected if proprioceptive feedback is necessary to the function of the ocular motor system, and if palisade endings are the critical proprioceptive structure.

  13. Chlorpheniramine produces spinal motor, proprioceptive and nociceptive blockades in rats.

    PubMed

    Tzeng, Jann-Inn; Lin, Heng-Teng; Chen, Yu-Wen; Hung, Ching-Hsia; Wang, Jhi-Joung

    2015-04-01

    This study aimed to assess the local anesthetic effects of chlorpheniramine in spinal anesthesia and is compared with mepivacaine, a widely-used local anesthetic. Spinal anesthesia with chlorpheniramine and mepivacaine was constructed in a dosage-dependent fashion after the rats were injected intrathecally. The spinal block effect of chlorpheniramine in motor function, nociception, and proprioception was compared to that of mepivacaine. We revealed that intrathecal chlorpheniramine and mepivacaine exhibited a dose-dependent spinal block of motor function, nociception, and proprioception. On the 50% effective dose (ED50) basis, the ranks of potencies in motor function, nociception, and proprioception were chlorpheniramine>mepivacaine (P<0.01 for the differences). On the equianesthetic basis (ED25, ED50, ED75), the duration of spinal anesthesia with chlorpheniramine was greater than that of mepivacaine (P<0.01 for the differences). Instead of mepivacaine, chlorpheniramine produced a greater duration of sensory blockade than the motor blockade. These preclinical data showed that chlorpheniramine has a better sensory-selective action over motor block to produce more potent and long-lasting spinal anesthesia than mepivacaine.

  14. A prospective study on knee proprioception after meniscal allograft transplantation.

    PubMed

    Thijs, Y; Witvrouw, E; Evens, B; Coorevits, P; Almqvist, F; Verdonk, R

    2007-06-01

    The meniscus plays an important role in the proprioceptive ability of the knee joint. The aim of this prospective study was to assess the short-term influence of a meniscus replacement on the proprioception of the knee. Fourteen patients who had undergone a fresh meniscal allograft transplantation between May 2001 and June 2003 were tested pre-operatively and 6 months post-operatively. Disability regarding pain, stiffness and functionality of the affected knee during daily activities was measured by the Western Ontario and McMaster Universities Arthritis (WOMAC) scale. The knee joint position sense was assessed using the Biodex System 3 isokinetic dynamometer. The results of the WOMAC scale showed no significant differences concerning pain, stiffness or knee function between the pre- and post-operative condition of the knee. Assessment of the knee joint position sense at a reference point of 70 degrees of knee flexion revealed a significant improvement of the proprioception of the operated knee at 6 months after surgery compared with the pre-operative condition. The results of this study suggest that although no significant improvement of pain and functionality of the operated knee occurred at this short-term follow-up period, a meniscal allograft transplantation seems to have a significant positive effect on the joint position sense of the previously meniscectomised knee.

  15. Shoulder proprioception is not related to throwing speed or accuracy in elite adolescent male baseball players.

    PubMed

    Freeston, Jonathan; Adams, Roger D; Rooney, Kieron

    2015-01-01

    Understanding factors that influence throwing speed and accuracy is critical to performance in baseball. Shoulder proprioception has been implicated in the injury risk of throwing athletes, but no such link has been established with performance outcomes. The purpose of this study was to describe any relationship between shoulder proprioception acuity and throwing speed or accuracy. Twenty healthy elite adolescent male baseball players (age, 19.6 ± 2.6 years), who had represented the state of New South Wales in the past 18 months, were assessed for bilateral active shoulder proprioception (shoulder rotation in 90° of arm abduction moving toward external rotation using the active movement extent discrimination apparatus), maximal throwing speed (MTS, meters per second measured via a radar gun), and accuracy (total error in centimeters determined by video analysis) at 80 and 100% of MTS. Although proprioception in the dominant and nondominant arms was significantly correlated with each other (r = 0.54, p < 0.01), no relationship was found between shoulder proprioception and performance. Shoulder proprioception was not a significant determinant of throwing performance such that high levels of speed and accuracy were achieved without a high degree of proprioception. There is no evidence to suggest therefore that this particular method of shoulder proprioception measurement should be implemented in clinical practice. Consequently, clinicians are encouraged to consider proprioception throughout the entire kinetic chain rather than the shoulder joint in isolation as a determining factor of performance in throwing athletes. PMID:24936898

  16. Shoulder proprioception is not related to throwing speed or accuracy in elite adolescent male baseball players.

    PubMed

    Freeston, Jonathan; Adams, Roger D; Rooney, Kieron

    2015-01-01

    Understanding factors that influence throwing speed and accuracy is critical to performance in baseball. Shoulder proprioception has been implicated in the injury risk of throwing athletes, but no such link has been established with performance outcomes. The purpose of this study was to describe any relationship between shoulder proprioception acuity and throwing speed or accuracy. Twenty healthy elite adolescent male baseball players (age, 19.6 ± 2.6 years), who had represented the state of New South Wales in the past 18 months, were assessed for bilateral active shoulder proprioception (shoulder rotation in 90° of arm abduction moving toward external rotation using the active movement extent discrimination apparatus), maximal throwing speed (MTS, meters per second measured via a radar gun), and accuracy (total error in centimeters determined by video analysis) at 80 and 100% of MTS. Although proprioception in the dominant and nondominant arms was significantly correlated with each other (r = 0.54, p < 0.01), no relationship was found between shoulder proprioception and performance. Shoulder proprioception was not a significant determinant of throwing performance such that high levels of speed and accuracy were achieved without a high degree of proprioception. There is no evidence to suggest therefore that this particular method of shoulder proprioception measurement should be implemented in clinical practice. Consequently, clinicians are encouraged to consider proprioception throughout the entire kinetic chain rather than the shoulder joint in isolation as a determining factor of performance in throwing athletes.

  17. Movement - uncontrolled or slow

    MedlinePlus

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

  18. Prolactin secretion after hypothalamic deafferentation in beef calves: response to haloperidol, alpha-methyl-rho-tyrosine, thyrotropin-releasing hormone and ovariectomy.

    PubMed

    Benoit, Allison M; Molina, Jose R; Lkhagvadorj, Sender; Anderson, Lloyd L

    2009-03-01

    In ruminant species photoperiod regulates prolactin (PRL) secretion. It is hypothesized that the inhibition of PRL secretion resides in dopaminergic neurons of the medial basal hypothalamus (MBH). To test this hypothesis, anterior (AHD), posterior (PHD) and complete (CHD) hypothalamic deafferentation and sham operation control (SOC) surgeries were carried out during May (long-day photoperiod) in beef heifer calves (6-8 mo old) to measure basal PRL secretion and PRL secretion as affected by intravenous secretagogues. On the day of surgery (day 0), PRL secretion reflected stress of anesthesia and surgery in all groups. Thyrotropin-releasing hormone (TRH), alpha-methyl-rho-tyrosine (alphaMrhoT), and haloperidol (HAL) was iv injected on days 11, 13 and 15, respectively. AHD, PHD, CHD, and SOC calves responded to TRH (100 microg) with an acute increase in PRL that peaked within 20 min. All heifers responded to alphaMrhoT (10 mg/kg BW) with an acute elevation in PRL within 10 min and remaining elevated for 3 h. HAL (0.1 mg/kg BW) induced an acute increase in PRL secretion in all groups, peaking within 15-30 min. Seven months later (December, short-day photoperiod) these heifers were ovariectomized. Basal plasma PRL levels were seasonally low, PRL secretion in AHD, PHD and CHD animals abruptly increased within 15 min to iv injection of 100 microg TRH to a greater amount than seen in SOC heifers. Although a biphasic effect on PRL secretion entrains under long-day and short-day photoperiods, hypothalamic deafferentation in cattle did not affect the pituitary gland's responsiveness to secretagogues.

  19. No Proprioceptive Deficits in Autism despite Movement-Related Sensory and Execution Impairments

    ERIC Educational Resources Information Center

    Fuentes, Christina T.; Mostofsky, Stewart H.; Bastian, Amy J.

    2011-01-01

    Autism spectrum disorder (ASD) often involves sensory and motor problems, yet the proprioceptive sense of limb position has not been directly assessed. We used three tasks to assess proprioception in adolescents with ASD who had motor and sensory perceptual abnormalities, and compared them to age- and IQ-matched controls. Results showed no group…

  20. Deficits in the Ability to Use Proprioceptive Feedback in Children with Hemiplegic Cerebral Palsy

    ERIC Educational Resources Information Center

    Goble, Daniel J.; Hurvitz, Edward A.; Brown, Susan H.

    2009-01-01

    Compared with motor impairment in children with hemiplegic cerebral palsy (CP), less attention has been paid to sensory feedback processing deficits. This includes, especially, proprioceptive information regarding arm position. This study examined the ability of children with hemiplegic CP to use proprioceptive feedback during a goal-directed…

  1. Upper Extremity Proprioception in Healthy Aging and Stroke Populations, and the Effects of Therapist- and Robot-Based Rehabilitation Therapies on Proprioceptive Function

    PubMed Central

    Hughes, Charmayne Mary Lee; Tommasino, Paolo; Budhota, Aamani; Campolo, Domenico

    2015-01-01

    The world’s population is aging, with the number of people ages 65 or older expected to surpass 1.5 billion people, or 16% of the global total. As people age, there are notable declines in proprioception due to changes in the central and peripheral nervous systems. Moreover, the risk of stroke increases with age, with approximately two-thirds of stroke-related hospitalizations occurring in people over the age of 65. In this literature review, we first summarize behavioral studies investigating proprioceptive deficits in normally aging older adults and stroke patients, and discuss the differences in proprioceptive function between these populations. We then provide a state of the art review the literature regarding therapist- and robot-based rehabilitation of the upper extremity proprioceptive dysfunction in stroke populations and discuss avenues of future research. PMID:25784872

  2. Neck proprioceptive training for balance function in patients with chronic poststroke hemiparesis: a case series.

    PubMed

    Kim, Gyoung-Mo; Oh, Duck-Won

    2014-10-01

    [Purpose] This study investigated the effects of neck proprioceptive training on the balance of patients with chronic poststroke hemiparesis. [Subjects] Three patients with chronic stroke were recruited for this study. [Methods] The subjects underwent neck proprioceptive training using the red light of a laser pointer (30 min daily, five times per week for 4 weeks). Outcome measures included the stability and weight distribution indices measured with a Tetrax system and Timed Up and Go (TUG) and proprioception tests. [Results] For all subjects, the stability and weight distribution indices increased by 1.87-9.66% in the eyes-open and eyes-closed conditions, and the TUG and proprioception test scores improved by 2.49-15.27%. [Conclusion] Neck proprioceptive training may be a good option for improving the balance function of patients with chronic poststroke hemiparesis.

  3. Generalization of force-field adaptation in proprioceptively-deafferented subjects.

    PubMed

    Lefumat, Hannah Z; Miall, R Chris; Cole, Jonathan D; Bringoux, Lionel; Bourdin, Christophe; Vercher, Jean-Louis; Sarlegna, Fabrice R

    2016-03-11

    Humans have the remarkable ability to adapt their motor behaviour to changes in body properties and/or environmental conditions, based on sensory feedback such as vision and proprioception. The role of proprioception has been highlighted for the adaptation to new upper-limb dynamics, which is known to generalize to the opposite, non-adapted limb in healthy individuals. Such interlimb transfer seems to depend on sensory feedback, and the present study assessed whether the chronic loss of proprioception precludes interlimb transfer of dynamic adaptation by testing two well-characterized proprioceptively-deafferented subjects. These had to reach toward visual targets with vision of the limb. For both deafferented subjects, we observed adaptation of the dominant arm to Coriolis forces and after-effects on non-dominant arm movements in different movement directions, thus indicating interlimb transfer. Overall, our findings show that motor learning can generalize across limbs and movement directions despite the loss of proprioceptive afferents.

  4. THE WORKING MEMORY BENEFITS OF PROPRIOCEPTIVELY DEMANDING TRAINING: A PILOT STUDY (.).

    PubMed

    Alloway, Ross G; Alloway, Tracy Packiam

    2015-06-01

    The aim of this study was to investigate the effect of proprioception on working memory. It was also of interest whether an acute and highly intensive period of exercise would yield working memory gains. The training group completed a series of proprioceptively demanding exercises. There were also control classroom and yoga groups. Working memory was measured using a backward digit recall test. The data indicated that active, healthy adults who undertook acute, proprioceptively demanding training improved working memory scores compared to the classroom and yoga groups. One possible reason that the training yielded significant working memory gains could be that the training was proprioceptively dynamic, requiring proprioception and at least one other factor-such as locomotion or navigation-at the same time, which may have contributed to the improvements in working memory performance.

  5. Generalization of force-field adaptation in proprioceptively-deafferented subjects.

    PubMed

    Lefumat, Hannah Z; Miall, R Chris; Cole, Jonathan D; Bringoux, Lionel; Bourdin, Christophe; Vercher, Jean-Louis; Sarlegna, Fabrice R

    2016-03-11

    Humans have the remarkable ability to adapt their motor behaviour to changes in body properties and/or environmental conditions, based on sensory feedback such as vision and proprioception. The role of proprioception has been highlighted for the adaptation to new upper-limb dynamics, which is known to generalize to the opposite, non-adapted limb in healthy individuals. Such interlimb transfer seems to depend on sensory feedback, and the present study assessed whether the chronic loss of proprioception precludes interlimb transfer of dynamic adaptation by testing two well-characterized proprioceptively-deafferented subjects. These had to reach toward visual targets with vision of the limb. For both deafferented subjects, we observed adaptation of the dominant arm to Coriolis forces and after-effects on non-dominant arm movements in different movement directions, thus indicating interlimb transfer. Overall, our findings show that motor learning can generalize across limbs and movement directions despite the loss of proprioceptive afferents. PMID:26826606

  6. THE WORKING MEMORY BENEFITS OF PROPRIOCEPTIVELY DEMANDING TRAINING: A PILOT STUDY (.).

    PubMed

    Alloway, Ross G; Alloway, Tracy Packiam

    2015-06-01

    The aim of this study was to investigate the effect of proprioception on working memory. It was also of interest whether an acute and highly intensive period of exercise would yield working memory gains. The training group completed a series of proprioceptively demanding exercises. There were also control classroom and yoga groups. Working memory was measured using a backward digit recall test. The data indicated that active, healthy adults who undertook acute, proprioceptively demanding training improved working memory scores compared to the classroom and yoga groups. One possible reason that the training yielded significant working memory gains could be that the training was proprioceptively dynamic, requiring proprioception and at least one other factor-such as locomotion or navigation-at the same time, which may have contributed to the improvements in working memory performance. PMID:26029969

  7. Head-controlled assistive telerobot with extended physiological proprioception capability

    NASA Astrophysics Data System (ADS)

    Salganicoff, Marcos; Rahman, Tariq; Mahoney, Ricardo; Pino, D.; Jayachandran, Vijay; Kumar, Vijay; Chen, Shoupu; Harwin, William S.

    1995-12-01

    People with disabilities such as quadriplegia can use mouth-sticks and head-sticks as extension devices to perform desired manipulations. These extensions provide extended proprioception which allows users to directly feel forces and other perceptual cues such as texture present at the tip of the mouth-stick. Such devices are effective for two principle reasons: because of their close contact with the user's tactile and proprioceptive sensing abilities; and because they tend to be lightweight and very stiff, and can thus convey tactile and kinesthetic information with high-bandwidth. Unfortunately, traditional mouth-sticks and head-sticks are limited in workspace and in the mechanical power that can be transferred because of user mobility and strength limitations. We describe an alternative implementation of the head-stick device using the idea of a virtual head-stick: a head-controlled bilateral force-reflecting telerobot. In this system the end-effector of the slave robot moves as if it were at the tip of an imaginary extension of the user's head. The design goal is for the system is to have the same intuitive operation and extended proprioception as a regular mouth-stick effector but with augmentation of workspace volume and mechanical power. The input is through a specially modified six DOF master robot (a PerForceTM hand-controller) whose joints can be back-driven to apply forces at the user's head. The manipulation tasks in the environment are performed by a six degree-of-freedom slave robot (the Zebra-ZEROTM) with a built-in force sensor. We describe the prototype hardware/software implementation of the system, control system design, safety/disability issues, and initial evaluation tasks.

  8. Somatosensory evoked potentials following proprioceptive stimulation of finger in man.

    PubMed

    Mima, T; Terada, K; Maekawa, M; Nagamine, T; Ikeda, A; Shibasaki, H

    1996-09-01

    Brisk passive flexion of the proximal interphalangeal joint of the middle finger, produced by using a newly devised instrument, elicited evoked potentials on the scalp. The present study carefully excluded the possible contribution of sensory modalities other than proprioception. The initial part of cortical response was a positive deflexion at the contralateral central area (P1 at 34.6 ms after the stimulus). This was followed by a midfrontal negative wave (N1 at 44.8 ms) and a clear positivity at the contralateral centroparietal area (P2 at 48.0 ms). The evoked responses persisted in spite of the abolition of cutaneous and joint afferents of the finger caused by ischemic anesthesia, but they were lost by ischemic anesthesia of the forearm. Thus, the cortical evoked responses obtained in this study most probably reflect muscle afferent inputs. The scalp distribution of P1 suggested that its cortical generator source was different from that of the N20-P20 components of evoked potentials to electrical median nerve stimulation. Brodmann areas 2 and 3a of human brain, which are known to receive deep receptor inputs, are the most plausible generator sites for the early components of the proprioception-related evoked responses. The amplitude of P2 was related to the velocity but not to the magnitude of movement. In conclusion, the present study established a method for recording the evoked responses to the brisk passive movement of the finger joint, which mainly reflect the dynamic aspects of proprioception mediated through muscle afferent. PMID:8891653

  9. Proprioceptive feedback and brain computer interface (BCI) based neuroprostheses.

    PubMed

    Ramos-Murguialday, Ander; Schürholz, Markus; Caggiano, Vittorio; Wildgruber, Moritz; Caria, Andrea; Hammer, Eva Maria; Halder, Sebastian; Birbaumer, Niels

    2012-01-01

    Brain computer interface (BCI) technology has been proposed for motor neurorehabilitation, motor replacement and assistive technologies. It is an open question whether proprioceptive feedback affects the regulation of brain oscillations and therefore BCI control. We developed a BCI coupled on-line with a robotic hand exoskeleton for flexing and extending the fingers. 24 healthy participants performed five different tasks of closing and opening the hand: (1) motor imagery of the hand movement without any overt movement and without feedback, (2) motor imagery with movement as online feedback (participants see and feel their hand, with the exoskeleton moving according to their brain signals, (3) passive (the orthosis passively opens and closes the hand without imagery) and (4) active (overt) movement of the hand and rest. Performance was defined as the difference in power of the sensorimotor rhythm during motor task and rest and calculated offline for different tasks. Participants were divided in three groups depending on the feedback receiving during task 2 (the other tasks were the same for all participants). Group 1 (n = 9) received contingent positive feedback (participants' sensorimotor rhythm (SMR) desynchronization was directly linked to hand orthosis movements), group 2 (n = 8) contingent "negative" feedback (participants' sensorimotor rhythm synchronization was directly linked to hand orthosis movements) and group 3 (n = 7) sham feedback (no link between brain oscillations and orthosis movements). We observed that proprioceptive feedback (feeling and seeing hand movements) improved BCI performance significantly. Furthermore, in the contingent positive group only a significant motor learning effect was observed enhancing SMR desynchronization during motor imagery without feedback in time. Furthermore, we observed a significantly stronger SMR desynchronization in the contingent positive group compared to the other groups during active and passive

  10. Conducting polymer actuators: From basic concepts to proprioceptive systems

    NASA Astrophysics Data System (ADS)

    Martinez Gil, Jose Gabriel

    Designers and engineers have been dreaming for decades of motors sensing, by themselves, working and surrounding conditions, as biological muscles do originating proprioception. Here bilayer full polymeric artificial muscles were checked up to very high cathodic potential limits (-2.5 V) in aqueous solution by cyclic voltammetry. The electrochemical driven exchange of ions from the conducting polymer film, and the concomitant Faradaic bending movement of the muscle, takes place in the full studied potential range. The presence of trapped counterion after deep reduction was corroborated by EDX determinations giving quite high electronic conductivity to the device. The large bending movement was used as a tool to quantify the amount of water exchanged per reaction unit (exchanged electron or ion). The potential evolutions of self-supported films of conducting polymers or conducting polymers (polypyrrole, polyaniline) coating different microfibers, during its oxidation/reduction senses working mechanical, thermal, chemical or electrical variables. The evolution of the muscle potential from electrochemical artificial muscles based on electroactive materials such as intrinsically conducting polymers and driven by constant currents senses, while working, any variation of the mechanical (trailed mass, obstacles, pressure, strain or stress), thermal or chemical conditions of work. One physically uniform artificial muscle includes one electrochemical motor and several sensors working simultaneously under the same driving reaction. Actuating (current and charge) and sensing (potential and energy) magnitudes are present, simultaneously, in the only two connecting wires and can be read by the computer at any time. From basic polymeric, mechanical and electrochemical principles a physicochemical equation describing artificial proprioception has been developed. It includes and describes, simultaneously, the evolution of the muscle potential during actuation as a function of the

  11. Associations between Proprioceptive Neural Pathway Structural Connectivity and Balance in People with Multiple Sclerosis.

    PubMed

    Fling, Brett W; Dutta, Geetanjali Gera; Schlueter, Heather; Cameron, Michelle H; Horak, Fay B

    2014-01-01

    Mobility and balance impairments are a hallmark of multiple sclerosis (MS), affecting nearly half of patients at presentation and resulting in decreased activity and participation, falls, injuries, and reduced quality of life. A growing body of work suggests that balance impairments in people with mild MS are primarily the result of deficits in proprioception, the ability to determine body position in space in the absence of vision. A better understanding of the pathophysiology of balance disturbances in MS is needed to develop evidence-based rehabilitation approaches. The purpose of the current study was to (1) map the cortical proprioceptive pathway in vivo using diffusion-weighted imaging and (2) assess associations between proprioceptive pathway white matter microstructural integrity and performance on clinical and behavioral balance tasks. We hypothesized that people with MS (PwMS) would have reduced integrity of cerebral proprioceptive pathways, and that reduced white matter microstructure within these tracts would be strongly related to proprioceptive-based balance deficits. We found poorer balance control on proprioceptive-based tasks and reduced white matter microstructural integrity of the cortical proprioceptive tracts in PwMS compared with age-matched healthy controls (HC). Microstructural integrity of this pathway in the right hemisphere was also strongly associated with proprioceptive-based balance control in PwMS and controls. Conversely, while white matter integrity of the right hemisphere's proprioceptive pathway was significantly correlated with overall balance performance in HC, there was no such relationship in PwMS. These results augment existing literature suggesting that balance control in PwMS may become more dependent upon (1) cerebellar-regulated proprioceptive control, (2) the vestibular system, and/or (3) the visual system.

  12. The effectiveness of proprioceptive training for improving motor function: a systematic review

    PubMed Central

    Aman, Joshua E.; Elangovan, Naveen; Yeh, I-Ling; Konczak, Jürgen

    2015-01-01

    Objective: Numerous reports advocate that training of the proprioceptive sense is a viable behavioral therapy for improving impaired motor function. However, there is little agreement of what constitutes proprioceptive training and how effective it is. We therefore conducted a comprehensive, systematic review of the available literature in order to provide clarity to the notion of training the proprioceptive system. Methods: Four major scientific databases were searched. The following criteria were subsequently applied: (1) A quantified pre- and post-treatment measure of proprioceptive function. (2) An intervention or training program believed to influence or enhance proprioceptive function. (3) Contained at least one form of treatment or outcome measure that is indicative of somatosensory function. From a total of 1284 articles, 51 studies fulfilled all criteria and were selected for further review. Results: Overall, proprioceptive training resulted in an average improvement of 52% across all outcome measures. Applying muscle vibration above 30 Hz for longer durations (i.e., min vs. s) induced outcome improvements of up to 60%. Joint position and target reaching training consistently enhanced joint position sense (up to 109%) showing an average improvement of 48%. Cortical stroke was the most studied disease entity but no clear evidence indicated that proprioceptive training is differentially beneficial across the reported diseases. Conclusions: There is converging evidence that proprioceptive training can yield meaningful improvements in somatosensory and sensorimotor function. However, there is a clear need for further work. Those forms of training utilizing both passive and active movements with and without visual feedback tended to be most beneficial. There is also initial evidence suggesting that proprioceptive training induces cortical reorganization, reinforcing the notion that proprioceptive training is a viable method for improving sensorimotor function

  13. Knee joint proprioception in ballet dancers and non-dancers.

    PubMed

    Dieling, Simone; van der Esch, Martin; Janssen, Thomas W J

    2014-01-01

    The aim of this study was to evaluate the influence of upper-leg muscle fatigue on knee joint proprioception in 13 ballet dancers and 13 non-dancer controls. Proprioception acuity, expressed as position and motion sense, was measured with an isokinetic dynamometer. The position and motion sense assessments were prior to and immediately after an isokinetic upper-leg muscle fatigue protocol. Participants wore blindfolds for both tasks to eliminate vision, an inflated air splint on their lower leg to neutralize cutaneous sensation, and headphones with white noise during the motion sense task to eliminate auditory cues. Results showed no significant differences in position and motion sense between dancers and controls in the non-fatigued state. In the fatigued state no significant differences were found in position sense between dancers and controls, while controls increased significantly in motion sense error (p = 0.030) and ballet dancers showed no change in motion sense. It is concluded that position sense and motion sense acuity are not affected by muscle fatigue in dancers, but motion sense is affected by muscle fatigue in non-dancers. PMID:25474293

  14. Proprioceptive body illusions modulate the visual perception of reaching distance.

    PubMed

    Petroni, Agustin; Carbajal, M Julia; Sigman, Mariano

    2015-01-01

    The neurobiology of reaching has been extensively studied in human and non-human primates. However, the mechanisms that allow a subject to decide-without engaging in explicit action-whether an object is reachable are not fully understood. Some studies conclude that decisions near the reach limit depend on motor simulations of the reaching movement. Others have shown that the body schema plays a role in explicit and implicit distance estimation, especially after motor practice with a tool. In this study we evaluate the causal role of multisensory body representations in the perception of reachable space. We reasoned that if body schema is used to estimate reach, an illusion of the finger size induced by proprioceptive stimulation should propagate to the perception of reaching distances. To test this hypothesis we induced a proprioceptive illusion of extension or shrinkage of the right index finger while participants judged a series of LEDs as reachable or non-reachable without actual movement. Our results show that reach distance estimation depends on the illusory perceived size of the finger: illusory elongation produced a shift of reaching distance away from the body whereas illusory shrinkage produced the opposite effect. Combining these results with previous findings, we suggest that deciding if a target is reachable requires an integration of body inputs in high order multisensory parietal areas that engage in movement simulations through connections with frontal premotor areas.

  15. Restoring tactile and proprioceptive sensation through a brain interface.

    PubMed

    Tabot, Gregg A; Kim, Sung Shin; Winberry, Jeremy E; Bensmaia, Sliman J

    2015-11-01

    Somatosensation plays a critical role in the dexterous manipulation of objects, in emotional communication, and in the embodiment of our limbs. For upper-limb neuroprostheses to be adopted by prospective users, prosthetic limbs will thus need to provide sensory information about the position of the limb in space and about objects grasped in the hand. One approach to restoring touch and proprioception consists of electrically stimulating neurons in somatosensory cortex in the hopes of eliciting meaningful sensations to support the dexterous use of the hands, promote their embodiment, and perhaps even restore the affective dimension of touch. In this review, we discuss the importance of touch and proprioception in everyday life, then describe approaches to providing artificial somatosensory feedback through intracortical microstimulation (ICMS). We explore the importance of biomimicry--the elicitation of naturalistic patterns of neuronal activation--and that of adaptation--the brain's ability to adapt to novel sensory input, and argue that both biomimicry and adaptation will play a critical role in the artificial restoration of somatosensation. We also propose that the documented re-organization that occurs after injury does not pose a significant obstacle to brain interfaces. While still at an early stage of development, sensory restoration is a critical step in transitioning upper-limb neuroprostheses from the laboratory to the clinic.

  16. Proprioceptive body illusions modulate the visual perception of reaching distance.

    PubMed

    Petroni, Agustin; Carbajal, M Julia; Sigman, Mariano

    2015-01-01

    The neurobiology of reaching has been extensively studied in human and non-human primates. However, the mechanisms that allow a subject to decide-without engaging in explicit action-whether an object is reachable are not fully understood. Some studies conclude that decisions near the reach limit depend on motor simulations of the reaching movement. Others have shown that the body schema plays a role in explicit and implicit distance estimation, especially after motor practice with a tool. In this study we evaluate the causal role of multisensory body representations in the perception of reachable space. We reasoned that if body schema is used to estimate reach, an illusion of the finger size induced by proprioceptive stimulation should propagate to the perception of reaching distances. To test this hypothesis we induced a proprioceptive illusion of extension or shrinkage of the right index finger while participants judged a series of LEDs as reachable or non-reachable without actual movement. Our results show that reach distance estimation depends on the illusory perceived size of the finger: illusory elongation produced a shift of reaching distance away from the body whereas illusory shrinkage produced the opposite effect. Combining these results with previous findings, we suggest that deciding if a target is reachable requires an integration of body inputs in high order multisensory parietal areas that engage in movement simulations through connections with frontal premotor areas. PMID:26110274

  17. Proprioception and Neuromuscular Control of the Shoulder After Muscle Fatigue

    PubMed Central

    Myers, Joseph B.; Guskiewicz, Kevin M.; Schneider, Robert A.; Prentice, William E.

    1999-01-01

    Objective: To examine the effects of fatigue on proprioception and neuromuscular control of the shoulder. Design and Setting: Subjects were randomly assigned to either an experimental group or control group. Subjects were tested using either the active angle-reproduction or the single- arm dynamic stability test. The subjects were then fatigued using a dynamometer performing continuous, concentric rotation exercises of the shoulder. Once fatigued, the subjects were posttested using the same test. One week later, the subjects returned and were pretested, fatigued, and posttested using the other test. Subjects: Thirty-two college-age (18 to 25 years) subjects (16 males, 16 females) with no history of glenohumeral instability or upper extremity injury volunteered for this study. Measurements: Absolute angular error was measured using an electrogoniometer present within the isokinetic dynamometer, while sway velocity was measured using a force-plate system. Results: Repeated-measures analysis of variance revealed a significant difference between the pretest and posttest values for absolute angular error in the experimental group, whereas no significant difference was revealed between pretest and posttest sway velocity for either the control or experimental group. Conclusions: Fatigue of the internal and external rotators of the shoulder decreased proprioception of the shoulder, while having no significant effect on neuromuscular control. ImagesFigure 1.Figure 2.Figure 3. PMID:16558590

  18. Restoring tactile and proprioceptive sensation through a brain interface.

    PubMed

    Tabot, Gregg A; Kim, Sung Shin; Winberry, Jeremy E; Bensmaia, Sliman J

    2015-11-01

    Somatosensation plays a critical role in the dexterous manipulation of objects, in emotional communication, and in the embodiment of our limbs. For upper-limb neuroprostheses to be adopted by prospective users, prosthetic limbs will thus need to provide sensory information about the position of the limb in space and about objects grasped in the hand. One approach to restoring touch and proprioception consists of electrically stimulating neurons in somatosensory cortex in the hopes of eliciting meaningful sensations to support the dexterous use of the hands, promote their embodiment, and perhaps even restore the affective dimension of touch. In this review, we discuss the importance of touch and proprioception in everyday life, then describe approaches to providing artificial somatosensory feedback through intracortical microstimulation (ICMS). We explore the importance of biomimicry--the elicitation of naturalistic patterns of neuronal activation--and that of adaptation--the brain's ability to adapt to novel sensory input, and argue that both biomimicry and adaptation will play a critical role in the artificial restoration of somatosensation. We also propose that the documented re-organization that occurs after injury does not pose a significant obstacle to brain interfaces. While still at an early stage of development, sensory restoration is a critical step in transitioning upper-limb neuroprostheses from the laboratory to the clinic. PMID:25201560

  19. Contributions of visual and proprioceptive information to travelled distance estimation during changing sensory congruencies.

    PubMed

    Campos, Jennifer L; Butler, John S; Bülthoff, Heinrich H

    2014-10-01

    Recent research has provided evidence that visual and body-based cues (vestibular, proprioceptive and efference copy) are integrated using a weighted linear sum during walking and passive transport. However, little is known about the specific weighting of visual information when combined with proprioceptive inputs alone, in the absence of vestibular information about forward self-motion. Therefore, in this study, participants walked in place on a stationary treadmill while dynamic visual information was updated in real time via a head-mounted display. The task required participants to travel a predefined distance and subsequently match this distance by adjusting an egocentric, in-depth target using a game controller. Travelled distance information was provided either through visual cues alone, proprioceptive cues alone or both cues combined. In the combined cue condition, the relationship between the two cues was manipulated by either changing the visual gain across trials (0.7×, 1.0×, 1.4×; Exp. 1) or the proprioceptive gain across trials (0.7×, 1.0×, 1.4×; Exp. 2). Results demonstrated an overall higher weighting of proprioception over vision. These weights were scaled, however, as a function of which sensory input provided more stable information across trials. Specifically, when visual gain was constantly manipulated, proprioceptive weights were higher than when proprioceptive gain was constantly manipulated. These results therefore reveal interesting characteristics of cue-weighting within the context of unfolding spatio-temporal cue dynamics.

  20. Emotional proprioception: Treatment of depression with afferent facial feedback.

    PubMed

    Finzi, Eric; Rosenthal, Norman E

    2016-09-01

    We develop the concept of emotional proprioception, whereby the muscles of facial expression play a central role in encoding and transmitting information to the brain's emotional circuitry, and describe its underlying neuroanatomy. We explore the role of facial expression in both reflecting and influencing depressed mood. The circuitry involved in this latter effect is a logical target for treatment with botulinum toxin, and we review the evidence in support of this strategy. Clinical trial data suggest that botulinum toxin is effective in treating depression. We discuss the clinical and theoretical implications of these data. This novel treatment approach is just one example of the potential importance of the cranial nerves in the treatment of depression. PMID:27344227

  1. Proprioceptive bimanual test in intrinsic and extrinsic coordinates.

    PubMed

    Iandolo, Riccardo; Squeri, Valentina; De Santis, Dalia; Giannoni, Psiche; Morasso, Pietro; Casadio, Maura

    2015-01-01

    Is there any difference between matching the position of the hands by asking the subjects to move them to the same spatial location or to mirror-symmetric locations with respect to the body midline? If the motion of the hands were planned in the extrinsic space, the mirror-symmetric task would imply an additional challenge, because we would need to flip the coordinates of the target on the other side of the workspace. Conversely, if the planning were done in intrinsic coordinates, in order to move both hands to the same spot in the workspace, we should compute different joint angles for each arm. Even if both representations were available to the subjects, the two tasks might lead to different results, providing some cue on the organization of the "body schema". In order to answer such questions, the middle fingertip of the non-dominant hand of a population of healthy subjects was passively moved by a manipulandum to 20 different target locations. Subjects matched these positions with the middle fingertip of their dominant hand. For most subjects, the matching accuracy was higher in the extrinsic modality both in terms of systematic error and variability, even for the target locations in which the configuration of the arms was the same for both modalities. This suggests that the matching performance of the subjects could be determined not only by proprioceptive information but also by the cognitive representation of the task: expressing the goal as reaching for the physical location of the hand in space is apparently more effective than requiring to match the proprioceptive representation of joint angles.

  2. Can textured insoles improve ankle proprioception and performance in dancers?

    PubMed

    Steinberg, Nili; Waddington, Gordon; Adams, Roger; Karin, Janet; Begg, Rezaul; Tirosh, Oren

    2016-08-01

    With the aim of determining both the acute and the chronic effects of textured insoles on the ankle discrimination and performance ability of dancers, 60 ballet dancers from the Australian Ballet School, aged 14-19 years, were divided into three groups (two intervention groups and a control group), age- and level-matched. In the first 5 weeks (weeks 1 to 5), the first intervention group (GRP1) was asked to wear textured insoles in their ballet shoes and the second intervention group (GRP2) was not given textured insoles to wear. In the next 5 weeks (weeks 6 to 10), GRP2 was asked to wear the same type of textured insoles and GRP1 did not wear the textured insoles. The control group (CTRL) did not wear textured insoles during the whole 10 weeks. All participants were tested preintervention, after 5 weeks and after 10 weeks for ankle discrimination score (AUC scores). Dance performance was assessed by 5-7 dance teachers. Pre-to-post change in AUC scores was significantly greater for the groups wearing insoles than for the controls (P = .046) and the size of pre-to-post changes did not differ between the two intervention groups (P = .834). Significant correlation was found between ankle discrimination score and performance scores, using the textured insoles (r = .412; P = .024). In conclusion, the stimulation to the proprioceptive system arising from textured insoles worn for five weeks was sufficient to improve the proprioceptive ability and performance ability of ballet dancers.

  3. Kinesthetic information facilitates saccades towards proprioceptive-tactile targets.

    PubMed

    Voudouris, Dimitris; Goettker, Alexander; Mueller, Stefanie; Fiehler, Katja

    2016-05-01

    Saccades to somatosensory targets have longer latencies and are less accurate and precise than saccades to visual targets. Here we examined how different somatosensory information influences the planning and control of saccadic eye movements. Participants fixated a central cross and initiated a saccade as fast as possible in response to a tactile stimulus that was presented to either the index or the middle fingertip of their unseen left hand. In a static condition, the hand remained at a target location for the entire block of trials and the stimulus was presented at a fixed time after an auditory tone. Therefore, the target location was derived only from proprioceptive and tactile information. In a moving condition, the hand was first actively moved to the same target location and the stimulus was then presented immediately. Thus, in the moving condition additional kinesthetic information about the target location was available. We found shorter saccade latencies in the moving compared to the static condition, but no differences in accuracy or precision of saccadic endpoints. In a second experiment, we introduced variable delays after the auditory tone (static condition) or after the end of the hand movement (moving condition) in order to reduce the predictability of the moment of the stimulation and to allow more time to process the kinesthetic information. Again, we found shorter latencies in the moving compared to the static condition but no improvement in saccade accuracy or precision. In a third experiment, we showed that the shorter saccade latencies in the moving condition cannot be explained by the temporal proximity between the relevant event (auditory tone or end of hand movement) and the moment of the stimulation. Our findings suggest that kinesthetic information facilitates planning, but not control, of saccadic eye movements to proprioceptive-tactile targets.

  4. Morphologic Indication for Proprioception in the Human Ciliary Muscle

    PubMed Central

    Flügel-Koch, Cassandra; Neuhuber, Winfried L.; Kaufman, Paul L.; Lütjen-Drecoll, Elke

    2009-01-01

    Purpose To search for proprioceptive nerve terminals in human ciliary muscle. Methods In 48 human donor eyes, histologic and ultrathin sections cut in different planes and wholemounts of the ciliary muscle were studied. Immunohistochemical staining with antibodies against pan-neuronal antigens and antigens reported as markers for sensory terminals in other organs was performed. Results Among the markers for proprioceptive terminals, only calretinin was present in the ciliary body. Calretinin-immunoreactive (IR) nerve terminals surrounded the posterior and reticular ciliary muscle tips and their elastic tendons. Terminals in that region contained mitochondria and neurofilaments. At the anterior tips larger terminals with numerous membrane-filled vesicles were located between the muscle fibers. The most elaborate network of calretinin-IR nerve fibers was present in the ground plate covering the circular muscle portion. Here calretinin-IR neurons with morphologic features of mechanoreception were present. Within the circular muscle portion numerous calretinin-IR ganglion cells were found. Their processes were connected to the calretinin-IR network but also surrounded ciliary muscle cells and NADPH-diaphorase-positive ganglion cells. Conclusions These morphologic findings indicate that there are proprioreceptors in the ciliary muscle that morphologically and presumably functionally differ at different locations. At the posterior muscle tips, the receptors could measure stretch of the tendons, whereas the large receptor organs located at the anterior muscle tips morphologically resemble mechanoreceptors measuring shear stress. The presence of the numerous intrinsic nerve cells indicates that contraction of the circular muscle portion can be modulated locally via a self-contained reflex arc. PMID:19578020

  5. Proprioceptive Bimanual Test in Intrinsic and Extrinsic Coordinates

    PubMed Central

    Iandolo, Riccardo; Squeri, Valentina; De Santis, Dalia; Giannoni, Psiche; Morasso, Pietro; Casadio, Maura

    2015-01-01

    Is there any difference between matching the position of the hands by asking the subjects to move them to the same spatial location or to mirror-symmetric locations with respect to the body midline? If the motion of the hands were planned in the extrinsic space, the mirror-symmetric task would imply an additional challenge, because we would need to flip the coordinates of the target on the other side of the workspace. Conversely, if the planning were done in intrinsic coordinates, in order to move both hands to the same spot in the workspace, we should compute different joint angles for each arm. Even if both representations were available to the subjects, the two tasks might lead to different results, providing some cue on the organization of the “body schema”. In order to answer such questions, the middle fingertip of the non-dominant hand of a population of healthy subjects was passively moved by a manipulandum to 20 different target locations. Subjects matched these positions with the middle fingertip of their dominant hand. For most subjects, the matching accuracy was higher in the extrinsic modality both in terms of systematic error and variability, even for the target locations in which the configuration of the arms was the same for both modalities. This suggests that the matching performance of the subjects could be determined not only by proprioceptive information but also by the cognitive representation of the task: expressing the goal as reaching for the physical location of the hand in space is apparently more effective than requiring to match the proprioceptive representation of joint angles. PMID:25741268

  6. The Right Supramarginal Gyrus Is Important for Proprioception in Healthy and Stroke-Affected Participants: A Functional MRI Study

    PubMed Central

    Ben-Shabat, Ettie; Matyas, Thomas A.; Pell, Gaby S.; Brodtmann, Amy; Carey, Leeanne M.

    2015-01-01

    Human proprioception is essential for motor control, yet its central processing is still debated. Previous studies of passive movements and illusory vibration have reported inconsistent activation patterns related to proprioception, particularly in high-order sensorimotor cortices. We investigated brain activation specific to proprioception, its laterality, and changes following stroke. Twelve healthy and three stroke-affected individuals with proprioceptive deficits participated. Proprioception was assessed clinically with the Wrist Position Sense Test, and participants underwent functional magnetic resonance imaging scanning. An event-related study design was used, where each proprioceptive stimulus of passive wrist movement was followed by a motor response of mirror ­copying with the other wrist. Left (LWP) and right (RWP) wrist proprioception were tested separately. Laterality indices (LIs) were calculated for the main cortical regions activated during proprioception. We found proprioception-related brain activation in high-order sensorimotor cortices in healthy participants especially in the supramarginal gyrus (SMG LWP z = 4.51, RWP z = 4.24) and the dorsal premotor cortex (PMd LWP z = 4.10, RWP z = 3.93). Right hemispheric dominance was observed in the SMG (LI LWP mean 0.41, SD 0.22; RWP 0.29, SD 0.20), and to a lesser degree in the PMd (LI LWP 0.34, SD 0.17; RWP 0.13, SD 0.25). In stroke-affected participants, the main difference in proprioception-related brain activation was reduced laterality in the right SMG. Our findings indicate that the SMG and PMd play a key role in proprioception probably due to their role in spatial processing and motor control, respectively. The findings from stroke-­affected individuals suggest that decreased right SMG function may be associated with decreased proprioception. We recommend that clinicians pay particular attention to the assessment and rehabilitation of proprioception following right hemispheric

  7. Degradation of mouse locomotor pattern in the absence of proprioceptive sensory feedback

    PubMed Central

    Akay, Turgay; Tourtellotte, Warren G.; Arber, Silvia; Jessell, Thomas M.

    2014-01-01

    Mammalian locomotor programs are thought to be directed by the actions of spinal interneuron circuits collectively referred to as “central pattern generators.” The contribution of proprioceptive sensory feedback to the coordination of locomotor activity remains less clear. We have analyzed changes in mouse locomotor pattern under conditions in which proprioceptive feedback is attenuated genetically and biomechanically. We find that locomotor pattern degrades upon elimination of proprioceptive feedback from muscle spindles and Golgi tendon organs. The degradation of locomotor pattern is manifest as the loss of interjoint coordination and alternation of flexor and extensor muscles. Group Ia/II sensory feedback from muscle spindles has a predominant influence in patterning the activity of flexor muscles, whereas the redundant activities of group Ia/II and group Ib afferents appear to determine the pattern of extensor muscle firing. These findings establish a role for proprioceptive feedback in the control of fundamental aspects of mammalian locomotor behavior. PMID:25389309

  8. A critical role for Piezo2 channels in the mechanotransduction of mouse proprioceptive neurons

    PubMed Central

    Florez-Paz, Danny; Bali, Kiran Kumar; Kuner, Rohini; Gomis, Ana

    2016-01-01

    Proprioceptors are responsible for the conscious sensation of limb position and movement, muscle tension or force, and balance. Recent evidence suggests that Piezo2 is a low threshold mechanosensory receptor in the peripheral nervous system, acting as a transducer for touch sensation and proprioception. Thus, we characterized proprioceptive neurons in the mesencephalic trigeminal nucleus that are involved in processing proprioceptive information from the face and oral cavity. This is a specific population of neurons that produce rapidly adapting mechanically-activated currents that are fully dependent on Piezo2. As such, we analyzed the deficits in balance and coordination caused by the selective deletion of the channel in proprioceptors (conditional knockout). The data clearly shows that Piezo2 fulfills a critical role in a defined homogeneous population of proprioceptor neurons that innervate the head muscles, demonstrating that this ion channel is essential for mammalian proprioceptive mechanotransduction. PMID:27184818

  9. A critical role for Piezo2 channels in the mechanotransduction of mouse proprioceptive neurons.

    PubMed

    Florez-Paz, Danny; Bali, Kiran Kumar; Kuner, Rohini; Gomis, Ana

    2016-05-17

    Proprioceptors are responsible for the conscious sensation of limb position and movement, muscle tension or force, and balance. Recent evidence suggests that Piezo2 is a low threshold mechanosensory receptor in the peripheral nervous system, acting as a transducer for touch sensation and proprioception. Thus, we characterized proprioceptive neurons in the mesencephalic trigeminal nucleus that are involved in processing proprioceptive information from the face and oral cavity. This is a specific population of neurons that produce rapidly adapting mechanically-activated currents that are fully dependent on Piezo2. As such, we analyzed the deficits in balance and coordination caused by the selective deletion of the channel in proprioceptors (conditional knockout). The data clearly shows that Piezo2 fulfills a critical role in a defined homogeneous population of proprioceptor neurons that innervate the head muscles, demonstrating that this ion channel is essential for mammalian proprioceptive mechanotransduction.

  10. Degradation of mouse locomotor pattern in the absence of proprioceptive sensory feedback.

    PubMed

    Akay, Turgay; Tourtellotte, Warren G; Arber, Silvia; Jessell, Thomas M

    2014-11-25

    Mammalian locomotor programs are thought to be directed by the actions of spinal interneuron circuits collectively referred to as "central pattern generators." The contribution of proprioceptive sensory feedback to the coordination of locomotor activity remains less clear. We have analyzed changes in mouse locomotor pattern under conditions in which proprioceptive feedback is attenuated genetically and biomechanically. We find that locomotor pattern degrades upon elimination of proprioceptive feedback from muscle spindles and Golgi tendon organs. The degradation of locomotor pattern is manifest as the loss of interjoint coordination and alternation of flexor and extensor muscles. Group Ia/II sensory feedback from muscle spindles has a predominant influence in patterning the activity of flexor muscles, whereas the redundant activities of group Ia/II and group Ib afferents appear to determine the pattern of extensor muscle firing. These findings establish a role for proprioceptive feedback in the control of fundamental aspects of mammalian locomotor behavior.

  11. [Syndrome of partial cholinergic deafferentation of the cortical mantle--a concept for describing the brain-behavior relationship in dementia diseases].

    PubMed

    Arendt, T

    1991-03-01

    The identification of morphological and biochemical changes in neurodegenerative disorders with both common and different patterns of neuropsychological dysfunction may help to define the neurobiological substrate of amnesic and dementing disorders, and, furthermore, will give some insight into the neuronal organisation of memory processes. The concept of "subcortical and cortical dementia" and the "cholinergic hypothesis of memory dysfunction" reflect two different theoretical approaches which relate psychopathological disturbances in Alzheimer's disease, Parkinson's disease, Korsakoff's psychosis and related conditions either to structurally or to chemically defined systems of the brain. In order to overcome limitations arising from this dichotomy of structural and chemical approaches to the brain-behaviour-relationship, the concept of a "syndrome of partial cholinergic deafferentation of the cortical mantle" is suggested in the present paper. This concept is supported by evidence derived from the biochemical, morphological and behavioural sequelae of acute and chronic experimental interference with the cholinergic afferentation of the cortical mantle by the application of neurotoxins, by pharmacological intervention and by neurotransplantation in rat. Regarding the cholinergic projection neurons of the basal forebrain and upper brainstem as components of the reticular activating system, the involvement of the cholinergic afferentation of the cortical mantle in the mediation of memory processes and their dysfunction under the conditions of neurodegenerative disorders can be explained on the basis of the "Hippocampal Memory Indexing Theory" of Teyler and DiScenna. PMID:2050315

  12. Cortical Auditory Deafferentation Induces Long-Term Plasticity in the Inferior Colliculus of Adult Rats: Microarray and qPCR Analysis

    PubMed Central

    Clarkson, Cheryl; Herrero-Turrión, M. Javier; Merchán, Miguel A.

    2012-01-01

    The cortico-collicular pathway is a bilateral excitatory projection from the cortex to the inferior colliculus (IC). It is asymmetric and predominantly ipsilateral. Using microarrays and RT-qPCR we analyzed changes in gene expression in the IC after unilateral lesions of the auditory cortex, comparing the ICs ipsi- and contralateral to the lesioned side. At 15 days after surgery there were mainly changes in gene expression in the IC ipsilateral to the lesion. Regulation primarily involved inflammatory cascade genes, suggesting a direct effect of degeneration rather than a neuronal plastic reorganization. Ninety days after the cortical lesion the ipsilateral IC showed a significant up-regulation of genes involved in apoptosis and axonal regeneration combined with a down-regulation of genes involved in neurotransmission, synaptic growth, and gap junction assembly. In contrast, the contralateral IC at 90 days post-lesion showed an up-regulation in genes primarily related to neurotransmission, cell proliferation, and synaptic growth. There was also a down-regulation in autophagy and neuroprotection genes. These findings suggest that the reorganization in the IC after descending pathway deafferentation is a long-term process involving extensive changes in gene expression regulation. Regulated genes are involved in many different neuronal functions, and the number and gene rearrangement profile seems to depend on the density of loss of the auditory cortical inputs. PMID:23233834

  13. Modeling fall propensity in Parkinson's disease: deficits in the attentional control of complex movements in rats with cortical-cholinergic and striatal-dopaminergic deafferentation.

    PubMed

    Kucinski, Aaron; Paolone, Giovanna; Bradshaw, Marc; Albin, Roger L; Sarter, Martin

    2013-10-16

    Cognitive symptoms, complex movement deficits, and increased propensity for falls are interrelated and levodopa-unresponsive symptoms in patients with Parkinson's disease (PD). We developed a test system for the assessment of fall propensity in rats and tested the hypothesis that interactions between loss of cortical cholinergic and striatal dopaminergic afferents increase fall propensity. Rats were trained to traverse stationary and rotating rods, placed horizontally or at inclines, and while exposed to distractors. Rats also performed an operant Sustained Attention Task (SAT). Partial cortical cholinergic and/or caudate dopaminergic deafferentation were produced by bilateral infusions of 192 IgG-saporin (SAP) into the basal forebrain and/or 6-hydroxydopamine (6-OHDA) into the caudate nucleus, respectively, modeling the lesions seen in early PD. Rats with dual cholinergic-dopaminergic lesions (DL) fell more frequently than SAP or 6-OHDA rats. Falls in DL rats were associated with incomplete rebalancing after slips and low traversal speed. Ladder rung walking and pasta handling performance did not indicate sensorimotor deficits. SAT performance was impaired in DL and SAP rats; however, SAT performance and falls were correlated only in DL rats. Furthermore, in DL rats, but not in rats with only dopaminergic lesions, the placement and size of dopaminergic lesion correlated significantly with fall rates. The results support the hypothesis that after dual cholinergic-dopaminergic lesions, attentional resources can no longer be recruited to compensate for diminished striatal control of complex movement, thereby "unmasking" impaired striatal control of complex movements and yielding falls. PMID:24133257

  14. Degeneration of proprioceptive sensory nerve endings in mice harboring amyotrophic lateral sclerosis-causing mutations.

    PubMed

    Vaughan, Sydney K; Kemp, Zachary; Hatzipetros, Theo; Vieira, Fernando; Valdez, Gregorio

    2015-12-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that primarily targets the motor system. Although much is known about the effects of ALS on motor neurons and glial cells, little is known about its effect on proprioceptive sensory neurons. This study examines proprioceptive sensory neurons in mice harboring mutations associated with ALS, in SOD1(G93A) and TDP43(A315T) transgenic mice. In both transgenic lines, we found fewer proprioceptive sensory neurons containing fluorescently tagged cholera toxin in their soma five days after injecting this retrograde tracer into the tibialis anterior muscle. We asked whether this is due to neuronal loss or selective degeneration of peripheral nerve endings. We found no difference in the total number and size of proprioceptive sensory neuron soma between symptomatic SOD1(G93A) and control mice. However, analysis of proprioceptive nerve endings in muscles revealed early and significant alterations at Ia/II proprioceptive nerve endings in muscle spindles before the symptomatic phase of the disease. Although these changes occur alongside those at α-motor axons in SOD1(G93A) mice, Ia/II sensory nerve endings degenerate in the absence of obvious alterations in α-motor axons in TDP43(A315T) transgenic mice. We next asked whether proprioceptive nerve endings are similarly affected in the spinal cord and found that nerve endings terminating on α-motor neurons are affected during the symptomatic phase and after peripheral nerve endings begin to degenerate. Overall, we show that Ia/II proprioceptive sensory neurons are affected by ALS-causing mutations, with pathological changes starting at their peripheral nerve endings.

  15. Proprioception rehabilitation training system for stroke patients using virtual reality technology.

    PubMed

    Kim, Sun I; Song, In-Ho; Cho, Sangwoo; Kim, In Young; Ku, Jeonghun; Kang, Youn Joo; Jang, Dong Pyo

    2013-01-01

    We investigated a virtual reality (VR) proprioceptive rehabilitation system that could manipulate the visual feedback of upper-limb during training and could do training by relying on proprioception feedback only. Virtual environments were designed in order to switch visual feedback on/off during upper-limb training. Two types of VR training tasks were designed for evaluating the effect of the proprioception focused training compared to the training with visual feedback. In order to evaluate the developed proprioception feedback virtual environment system, we recruited ten stroke patients (age: 54.7± 7.83years, on set: 3.29± 3.83 years). All patients performed three times PFVE task in order to check the improvement of proprioception function just before training session, after one week training, and after all training. In a comparison between FMS score and PFVE, the FMS score had a significant relationship with the error distance(r = -.662, n=10, p = .037) and total movement distance(r = -.726, n=10, p = .018) in PFVE. Comparing the training effect between in virtual environment with visual feedback and with proprioception, the click count, error distance and total error distance was more reduced in PFVE than VFVE. (Click count: p = 0.005, error distance: p = 0.001, total error distance: p = 0.007). It suggested that the proprioception feedback rather than visual feedback could be effective means to enhancing motor control during rehabilitation training. The developed VR system for rehabilitation has been verified in that stroke patients improved motor control after VR proprioception feedback training.

  16. Disruption in proprioception from long-term thalamic deep brain stimulation: a pilot study

    PubMed Central

    Semrau, Jennifer A.; Herter, Troy M.; Kiss, Zelma H.; Dukelow, Sean P.

    2015-01-01

    Deep brain stimulation (DBS) is an excellent treatment for tremor and is generally thought to be reversible by turning off stimulation. For tremor, DBS is implanted in the ventrointermedius (Vim) nucleus of the thalamus, a region that relays proprioceptive information for movement sensation (kinaesthesia). Gait disturbances have been observed with bilateral Vim DBS, but the long-term effects on proprioceptive processing are unknown. We aimed to determine whether Vim DBS surgical implantation or stimulation leads to proprioceptive deficits in the upper limb. We assessed two groups of tremor subjects on measures of proprioception (kinaesthesia, position sense) and motor function using a robotic exoskeleton. In the first group (Surgery), we tested patients before and after implantation of Vim DBS, but before DBS was turned on to determine if proprioceptive deficits were inherent to tremor or caused by DBS implantation. In the second group (Stim), we tested subjects with chronically implanted Vim DBS ON and OFF stimulation. Compared to controls, there were no proprioceptive deficits before or after DBS implantation in the Surgery group. Surprisingly, those that received chronic long-term stimulation (LT-stim, 3–10 years) displayed significant proprioceptive deficits ON and OFF stimulation not present in subjects with chronic short-term stimulation (ST-stim, 0.5–2 years). LT-stim had significantly larger variability and reduced workspace area during the position sense assessment. During the kinesthetic assessment, LT-stim made significantly larger directional errors and consistently underestimated the speed of the robot, despite generating normal movement speeds during motor assessment. Chronic long-term Vim DBS may potentially disrupt proprioceptive processing, possibly inducing irreversible plasticity in the Vim nucleus and/or its network connections. Our findings in the upper limb may help explain some of the gait disturbances seen by others following Vim DBS

  17. Preliminary analysis of non-dominant proprioceptive acuity and interlimb asymmetry in the human wrist.

    PubMed

    Contu, Sara; Cappello, Leonardo; Konczak, Jurgen; Masia, Lorenzo

    2015-08-01

    Proprioception provides information about limb configuration which are essential for planning and controlling its posture and movement. Asymmetries in the way dominant and non-dominant limbs exploit proprioceptive information have been previously evaluated, with contradictory results due to the difference in the employed methodology. A measure of proprioceptive acuity that does not reflect the influence of one limb on the other consists in the evaluation of the psychophysical threshold. This metric, evaluated separately for each limb and involving only passive movements, reflects a reliable measure of proprioceptive acuity. The aim of this work is to first evaluate the proprioceptive acuity of the non-dominant wrist joint in flexion/extension and adduction/abduction and to compare these results to the acuity of the dominant wrist. Data were collected during a unidirectional 2-alternative-forcedchoice test performed by six right-handed subjects. We found acuity of 1.31°, 1.26°, 1.33° and 1.63° respectively for abduction, adduction, extension and flexion of the non-dominant wrist. Acuity of the dominant wrist was assessed for five of the subjects for abduction and flexion and resulted lower (mean values were respectively 1.64° and 2.14°). The preliminary results suggest a leading role of the non-dominant wrist in the processing of the proprioceptive feedback.

  18. Robot-Aided Mapping of Wrist Proprioceptive Acuity across a 3D Workspace.

    PubMed

    Marini, Francesca; Squeri, Valentina; Morasso, Pietro; Konczak, Jürgen; Masia, Lorenzo

    2016-01-01

    Proprioceptive signals from peripheral mechanoreceptors form the basis for bodily perception and are known to be essential for motor control. However we still have an incomplete understanding of how proprioception differs between joints, whether it differs among the various degrees-of-freedom (DoFs) within a particular joint, and how such differences affect motor control and learning. We here introduce a robot-aided method to objectively measure proprioceptive function: specifically, we systematically mapped wrist proprioceptive acuity across the three DoFs of the wrist/hand complex with the aim to characterize the wrist position sense. Thirty healthy young adults performed an ipsilateral active joint position matching task with their dominant wrist using a haptic robotic exoskeleton. Our results indicate that the active wrist position sense acuity is anisotropic across the joint, with the abduction/adduction DoF having the highest acuity (the error of acuity for flexion/extension is 4.64 ± 0.24°; abduction/adduction: 3.68 ± 0.32°; supination/pronation: 5.15 ± 0.37°) and they also revealed that proprioceptive acuity decreases for smaller joint displacements. We believe this knowledge is imperative in a clinical scenario when assessing proprioceptive deficits and for understanding how such sensory deficits relate to observable motor impairments.

  19. Robot-Aided Mapping of Wrist Proprioceptive Acuity across a 3D Workspace.

    PubMed

    Marini, Francesca; Squeri, Valentina; Morasso, Pietro; Konczak, Jürgen; Masia, Lorenzo

    2016-01-01

    Proprioceptive signals from peripheral mechanoreceptors form the basis for bodily perception and are known to be essential for motor control. However we still have an incomplete understanding of how proprioception differs between joints, whether it differs among the various degrees-of-freedom (DoFs) within a particular joint, and how such differences affect motor control and learning. We here introduce a robot-aided method to objectively measure proprioceptive function: specifically, we systematically mapped wrist proprioceptive acuity across the three DoFs of the wrist/hand complex with the aim to characterize the wrist position sense. Thirty healthy young adults performed an ipsilateral active joint position matching task with their dominant wrist using a haptic robotic exoskeleton. Our results indicate that the active wrist position sense acuity is anisotropic across the joint, with the abduction/adduction DoF having the highest acuity (the error of acuity for flexion/extension is 4.64 ± 0.24°; abduction/adduction: 3.68 ± 0.32°; supination/pronation: 5.15 ± 0.37°) and they also revealed that proprioceptive acuity decreases for smaller joint displacements. We believe this knowledge is imperative in a clinical scenario when assessing proprioceptive deficits and for understanding how such sensory deficits relate to observable motor impairments. PMID:27536882

  20. The role of differential delays in integrating transient visual and proprioceptive information

    PubMed Central

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

    2014-01-01

    Many actions involve limb movements toward a target. Visual and proprioceptive estimates are available online, and by optimally combining (Ernst and Banks, 2002) both modalities during the movement, the system can increase the precision of the hand estimate. The notion that both sensory modalities are integrated is also motivated by the intuition that we do not consciously perceive any discrepancy between the felt and seen hand's positions. This coherence as a result of integration does not necessarily imply realignment between the two modalities (Smeets et al., 2006). For example, the two estimates (visual and proprioceptive) might be different without either of them (e.g., proprioception) ever being adjusted after recovering the other (e.g., vision). The implication that the felt and seen positions might be different has a temporal analog. Because the actual feedback from the hand at a given instantaneous position reaches brain areas at different times for proprioception and vision (shorter for proprioception), the corresponding instantaneous unisensory position estimates will be different, with the proprioceptive one being ahead of the visual one. Based on the assumption that the system integrates optimally and online the available evidence from both senses, we introduce a temporal mechanism that explains the reported overestimation of hand positions when vision is occluded for active and passive movements (Gritsenko et al., 2007) without the need to resort to initial feedforward estimates (Wolpert et al., 1995). We set up hypotheses to test the validity of the model, and we contrast simulation-based predictions with empirical data. PMID:24550870

  1. Robot-Aided Mapping of Wrist Proprioceptive Acuity across a 3D Workspace

    PubMed Central

    Marini, Francesca; Squeri, Valentina; Morasso, Pietro; Konczak, Jürgen; Masia, Lorenzo

    2016-01-01

    Proprioceptive signals from peripheral mechanoreceptors form the basis for bodily perception and are known to be essential for motor control. However we still have an incomplete understanding of how proprioception differs between joints, whether it differs among the various degrees-of-freedom (DoFs) within a particular joint, and how such differences affect motor control and learning. We here introduce a robot-aided method to objectively measure proprioceptive function: specifically, we systematically mapped wrist proprioceptive acuity across the three DoFs of the wrist/hand complex with the aim to characterize the wrist position sense. Thirty healthy young adults performed an ipsilateral active joint position matching task with their dominant wrist using a haptic robotic exoskeleton. Our results indicate that the active wrist position sense acuity is anisotropic across the joint, with the abduction/adduction DoF having the highest acuity (the error of acuity for flexion/extension is 4.64 ± 0.24°; abduction/adduction: 3.68 ± 0.32°; supination/pronation: 5.15 ± 0.37°) and they also revealed that proprioceptive acuity decreases for smaller joint displacements. We believe this knowledge is imperative in a clinical scenario when assessing proprioceptive deficits and for understanding how such sensory deficits relate to observable motor impairments. PMID:27536882

  2. Increasing cutaneous afferent feedback improves proprioceptive accuracy at the knee in patients with sensory ataxia.

    PubMed

    Macefield, Vaughan G; Norcliffe-Kaufmann, Lucy; Goulding, Niamh; Palma, Jose-Alberto; Fuente Mora, Cristina; Kaufmann, Horacio

    2016-02-01

    Hereditary sensory and autonomic neuropathy type III (HSAN III) features disturbed proprioception and a marked ataxic gait. We recently showed that joint angle matching error at the knee is positively correlated with the degree of ataxia. Using intraneural microelectrodes, we also documented that these patients lack functional muscle spindle afferents but have preserved large-diameter cutaneous afferents, suggesting that patients with better proprioception may be relying more on proprioceptive cues provided by tactile afferents. We tested the hypothesis that enhancing cutaneous sensory feedback by stretching the skin at the knee joint using unidirectional elasticity tape could improve proprioceptive accuracy in patients with a congenital absence of functional muscle spindles. Passive joint angle matching at the knee was used to assess proprioceptive accuracy in 25 patients with HSAN III and 9 age-matched control subjects, with and without taping. Angles of the reference and indicator knees were recorded with digital inclinometers and the absolute error, gradient, and correlation coefficient between the two sides calculated. Patients with HSAN III performed poorly on the joint angle matching test [mean matching error 8.0 ± 0.8° (±SE); controls 3.0 ± 0.3°]. Following application of tape bilaterally to the knee in an X-shaped pattern, proprioceptive performance improved significantly in the patients (mean error 5.4 ± 0.7°) but not in the controls (3.0 ± 0.2°). Across patients, but not controls, significant increases in gradient and correlation coefficient were also apparent following taping. We conclude that taping improves proprioception at the knee in HSAN III, presumably via enhanced sensory feedback from the skin.

  3. Robot-Assisted Proprioceptive Training with Added Vibro-Tactile Feedback Enhances Somatosensory and Motor Performance

    PubMed Central

    Cuppone, Anna Vera; Squeri, Valentina; Semprini, Marianna; Masia, Lorenzo; Konczak, Jürgen

    2016-01-01

    This study examined the trainability of the proprioceptive sense and explored the relationship between proprioception and motor learning. With vision blocked, human learners had to perform goal-directed wrist movements relying solely on proprioceptive/haptic cues to reach several haptically specified targets. One group received additional somatosensory movement error feedback in form of vibro-tactile cues applied to the skin of the forearm. We used a haptic robotic device for the wrist and implemented a 3-day training regimen that required learners to make spatially precise goal-directed wrist reaching movements without vision. We assessed whether training improved the acuity of the wrist joint position sense. In addition, we checked if sensory learning generalized to the motor domain and improved spatial precision of wrist tracking movements that were not trained. The main findings of the study are: First, proprioceptive acuity of the wrist joint position sense improved after training for the group that received the combined proprioceptive/haptic and vibro-tactile feedback (VTF). Second, training had no impact on the spatial accuracy of the untrained tracking task. However, learners who had received VTF significantly reduced their reliance on haptic guidance feedback when performing the untrained motor task. That is, concurrent VTF was highly salient movement feedback and obviated the need for haptic feedback. Third, VTF can be also provided by the limb not involved in the task. Learners who received VTF to the contralateral limb equally benefitted. In conclusion, somatosensory training can significantly enhance proprioceptive acuity within days when learning is coupled with vibro-tactile sensory cues that provide feedback about movement errors. The observable sensory improvements in proprioception facilitates motor learning and such learning may generalize to the sensorimotor control of the untrained motor tasks. The implications of these findings for

  4. The co-constitution of the self and the world: action and proprioceptive coupling

    PubMed Central

    Gapenne, Olivier

    2014-01-01

    This article proposes a theoretical reflection on the conditions for the constitution of a distinction between the self and the world by a cognitive system. The main hypothesis is the following: proprioception, as a sensory system that is habitually dedicated essentially to experience of the body, is conceived here as a coupling which is necessary for the dual and concomitant constitution of a bodily self and of a distal perceptual field. After recalling the singular characteristics of proprioceptive coupling, three lines of thought are developed. The first, which is notably inspired by research on sensory substitution, aims at emphasizing the indispensable role of action in the context of such perceptual learning. In a second part, this hypothesis is tested against opposing arguments. In particular, we shall discuss, in the context of what Braitenberg called a synthetic psychology, the emergence of oriented behaviors in simple robots that can be regulated by sensory regulations which are strictly external, since these robots do not have any form of “proprioception.” In the same vein, this part also provides the opportunity to discuss the argument concerning a bijective relation between action and proprioception; it has been argued by others that because of this strict bijection it is not possible for proprioception to be the basis for the constitution of an exteriority. The third part, which is more prospective, suggests that it is important to take the measure of the phylogenetic history of this exteriority, starting from unicellular organisms. Taking into account the literature which attests the existence of proprioception even amongst the most elementary living organisms, this leads us to propose that the coupling of proprioception to action is very primitive, and that the role we propose for it in the co-constitution of an exteriority and self is probably already at work in the simplest living organisms. PMID:24971073

  5. Modelling muscle spindle dynamics for a proprioceptive prosthesis.

    PubMed

    Williams, Ian; Constandinou, Timothy G

    2013-01-01

    Muscle spindles are found throughout our skeletal muscle tissue and continuously provide us with a sense of our limbs' position and motion (proprioception). This paper advances a model for generating artificial muscle spindle signals for a prosthetic limb, with the aim of one day providing amputees with a sense of feeling in their artificial limb. By utilising the Opensim biomechanical modelling package the relationship between a joint's angle and the length of surrounding muscles is estimated for a prosthetic limb. This is then applied to the established Mileusnic model to determine the associated muscle spindle firing pattern. This complete system model is then reduced to allow for a computationally efficient hardware implementation. This reduction is achieved with minimal impact on accuracy by selecting key mono-articular muscles and fitting equations to relate joint angle to muscle length. Parameter values fitting the Mileusnic model to human spindles are then proposed and validated against previously published human neural recordings. Finally, a model for fusimotor signals is also proposed based on data previously recorded from reduced animal experiments.

  6. Proprioception in the extraocular muscles of mammals and man.

    PubMed

    Blumer, Roland; Konacki, Kadriye Zeynep; Streicher, Johannes; Hoetzenecker, Wolfram; Blumer, Michael Josef Franz; Lukas, Julius-Robert

    2006-06-01

    This article summarizes the authors' previous studies on proprioceptors in extraocular muscles (EOMs) of mammals and man. They report on muscle spindles in the EOMs of man, Golgi tendon organs in the EOMs of even-toed ungulates, and palisade endings in the EOMs of the cat. Muscle spindles: Muscle spindles are present in the EOMs of some mammals and in the EOMs of man. Compared with muscle spindles in other skeletal muscles, those in human EOMs exhibit structural differences. These structural differences may indicate a special function. Golgi tendon organs: Golgi tendon organs are absent in human EOMs. Golgi tendon organs exhibiting a specific morphology are present in the EOMs of even-toed ungulates. Their high number and rich innervation indicate functional importance. Palisade endings: Palisade endings are nervous end organs confined to the EOMs of mammals and man. It is assumed that these organs have a proprioceptive function. The authors show that palisade endings are immunoreactive for antibodies against choline acetyltransferase. Neuromuscular contacts, if present in palisade endings, are alpha -bungarotoxin positive as well. Taken together, these results show that palisade endings exhibit molecular characteristics of effector organs.

  7. Development of a BIONic muscle spindle for prosthetic proprioception.

    PubMed

    Sachs, Nicholas A; Loeb, Gerald E

    2007-06-01

    The replacement of proprioceptive function, whether for conscious sensation or feedback control, is likely to be an important aspect of neural prosthetic restoration of limb movements. Thus far, however, it has been hampered by the absence of unobtrusive sensors. We propose a method whereby fully implanted, telemetrically operated BIONs monitor muscle movement, and thereby detect changes in joint angle(s) and/or limb posture without requiring the use of secondary components attached to limb segments or external reference frames. The sensor system is designed to detect variations in the electrical coupling between devices implanted in neighboring muscles that result from changes in their relative position as the muscles contract and stretch with joint motion. The goal of this study was to develop and empirically validate mathematical models of the sensing scheme and to use computer simulations to provide an early proof of concept and inform design of the overall sensor system. Results from experiments using paired dipoles in a saline bath and finite element simulations have given insight into the current distribution and potential gradients exhibited within bounded anisotropic environments similar to a human limb segment and demonstrated an anticipated signal to noise ratio of at least 8:1 for submillimeter resolution of relative implant movement over a range of implant displacements up to 15 cm.

  8. Proprioceptive Training and Injury Prevention in a Professional Men's Basketball Team: A Six-Year Prospective Study

    PubMed Central

    Bianchi, Roberto; Rocca, Flavio; Mamo, Carlo

    2016-01-01

    Abstract Riva, D, Bianchi, R, Rocca, F, and Mamo, C. Proprioceptive training and injury prevention in a professional men's basketball team: A six-year prospective study. J Strength Cond Res 30(2): 461–475, 2016—Single limb stance instability is a risk factor for lower extremity injuries. Therefore, the development of proprioception may play an important role in injury prevention. This investigation considered a professional basketball team for 6 years, integrating systematic proprioceptive activity in the training routine. The purpose was to assess the effectiveness of proprioceptive training programs based on quantifiable instability, to reduce ankle sprains, knee sprains, and low back pain through developing refined and long-lasting proprioceptive control. Fifty-five subjects were studied. In the first biennium (2004–2006), the preventive program consisted of classic proprioceptive exercises. In the second biennium (2006–2008), the proprioceptive training became quantifiable and interactive by means of electronic proprioceptive stations. In the third biennium (2008–2010), the intensity and the training volume increased while the session duration became shorter. Analysis of variance was used to analyze the differences in proprioceptive control between groups, years, and bienniums. Injury rates and rate ratios of injury during practices and games were estimated. The results showed a statistically significant reduction in the occurrence of ankle sprains by 81% from the first to the third biennium (p < 0.001). Low back pain showed similar results with a reduction of 77.8% (p < 0.005). The reduction in knee sprains was 64.5% (not significant). Comparing the third biennium with the level of all new entry players, proprioceptive control improved significantly by 72.2% (p < 0.001). These findings indicate that improvements in proprioceptive control in single stance may be a key factor for an effective reduction in ankle sprains, knee sprains, and low back pain

  9. Computationally efficient modeling of proprioceptive signals in the upper limb for prostheses: a simulation study

    PubMed Central

    Williams, Ian; Constandinou, Timothy G.

    2014-01-01

    Accurate models of proprioceptive neural patterns could 1 day play an important role in the creation of an intuitive proprioceptive neural prosthesis for amputees. This paper looks at combining efficient implementations of biomechanical and proprioceptor models in order to generate signals that mimic human muscular proprioceptive patterns for future experimental work in prosthesis feedback. A neuro-musculoskeletal model of the upper limb with 7 degrees of freedom and 17 muscles is presented and generates real time estimates of muscle spindle and Golgi Tendon Organ neural firing patterns. Unlike previous neuro-musculoskeletal models, muscle activation and excitation levels are unknowns in this application and an inverse dynamics tool (static optimization) is integrated to estimate these variables. A proprioceptive prosthesis will need to be portable and this is incompatible with the computationally demanding nature of standard biomechanical and proprioceptor modeling. This paper uses and proposes a number of approximations and optimizations to make real time operation on portable hardware feasible. Finally technical obstacles to mimicking natural feedback for an intuitive proprioceptive prosthesis, as well as issues and limitations with existing models, are identified and discussed. PMID:25009463

  10. Manual aiming in healthy aging: does proprioceptive acuity make the difference?

    PubMed

    Helsen, Werner F; Van Halewyck, Florian; Levin, Oron; Boisgontier, Matthieu P; Lavrysen, Ann; Elliott, Digby

    2016-04-01

    The present study examines whether non-active older adults are more dependent on visual information when executing aiming movements and whether age-related declines in proprioception play a mediating role herein. Young (N = 40) and older adults (N = 38) were divided into physically active and non-active subgroups based on self-reported sports participation levels. In experiment 1, participants executed wrist-aiming movements with and without visual feedback. In experiment 2, passive proprioceptive acuity was assessed using wrist motion detection and position matching tests. Results showed similar aiming accuracy across age groups both with and without visual feedback, but older adults exhibited longer movement times, prolonged homing-in phase, and made more corrective submovements. Passive proprioceptive acuity was significantly affected by physical activity level and age, with participants in the active group scoring better than their non-active peers. However, these declines did not predict performance changes on the aiming task. Taken together, our observations suggest that decline in proprioceptive acuity did not predict performance changes on the aiming task and older adults were able to compensate for their decreased motion and position sense when allowed sufficient time. In line with these observations, we proposed that older adults are able to compensate for their decline in proprioception by increasing their reliance on predictive models.

  11. Proprioceptive impairments associated with knee osteoarthritis are not generalized to the ankle and elbow joints.

    PubMed

    Shanahan, Camille J; Wrigley, Tim V; Farrell, Michael J; Bennell, Kim L; Hodges, Paul W

    2015-06-01

    The mechanisms for proprioceptive changes associated with knee osteoarthritis (OA) remain elusive. Observations of proprioceptive changes in both affected knees and other joints imply more generalized mechanisms for proprioceptive impairment. However, evidence for a generalized effect remains controversial. This study examined whether joint repositioning proprioceptive deficits are localized to the diseased joint (knee) or generalized across other joints (elbow and ankle) in people with knee OA. Thirty individuals with right knee OA (17 female, 66±7 [mean±SD] years) of moderate/severe radiographic disease severity and 30 healthy asymptomatic controls of comparable age (17 female, 65±8years) performed active joint repositioning tests of the knee, ankle and elbow in randomised order in supine. Participants with knee OA had a larger relative error for joint repositioning of the knee than the controls (OA: 2.7±2.1°, control: 1.6±1.7°, p=.03). Relative error did not differ between groups for the ankle (OA: 2.2±2.5°, control: 1.9±1.3°, p=.50) or elbow (OA: 2.5±3.3°, control: 2.9±2.8°, p=.58). These results are consistent with a mechanism for proprioceptive change that is localized to the knee joint. This could be mediated by problems with mechanoreceptors, processing/relay of somatosensory input to higher centers, or joint-specific interference with cognitive processes by pain.

  12. Preserved motor learning after stroke is related to the degree of proprioceptive deficit

    PubMed Central

    Vidoni, Eric D; Boyd, Lara A

    2009-01-01

    Background Most motor learning theories posit that proprioceptive sensation serves an important role in acquiring and performing movement patterns. However, we recently demonstrated that experimental disruption of proprioception peripherally altered motor performance but not motor learning in humans. Little work has considered humans with central nervous system damage. The purpose of the present study was to specifically consider the relationship between proprioception and motor learning at the level of the central nervous system in humans. Methods Individuals with chronic (> 6mo) stroke and similarly aged healthy participants performed a continuous tracking task with an embedded repeating segment over two days and returned on a third day for retention testing. A limb-position matching task was used to quantify proprioception. Results Individuals with chronic stroke demonstrated the ability to learn to track a repeating segment; however, the magnitude of behavioral change associated with repeated segment-specific learning was directly related to the integrity of central proprioceptive processing as indexed by our limb-position matching task. Conclusion These results support the importance of central sensory processing for motor learning. The confirmation of central sensory processing dependent motor learning in humans is discussed in the context of our prior report of preserved motor learning when sensation is disrupted peripherally. PMID:19715593

  13. A quantitative and standardized robotic method for the evaluation of arm proprioception after stroke.

    PubMed

    Simo, Lucia S; Ghez, Claude; Botzer, Lior; Scheidt, Robert A

    2011-01-01

    Stroke often results in both motor and sensory deficits, which may interact in the manifested functional impairment. Proprioception is known to play important roles in the planning and control of limb posture and movement; however, the impact of proprioceptive deficits on motor function has been difficult to elucidate due in part to the qualitative nature of available clinical tests. We present a quantitative and standardized method for evaluating proprioception in tasks directly relevant to those used to assess motor function. Using a robotic manipulandum that exerted controlled displacements of the hand, stroke participants were evaluated, and compared with a control group, in their ability to detect such displacements in a 2-alternative, forced-choice paradigm. A psychometric function parameterized the decision process underlying the detection of the hand displacements. The shape of this function was determined by a signal detection threshold and by the variability of the response about this threshold. Our automatic procedure differentiates between participants with and without proprioceptive deficits and quantifies functional proprioceptive sensation on a magnitude scale that is meaningful for ongoing studies of degraded motor function in comparable horizontal movements.

  14. Do voluntary strength, proprioception, range of motion, or postural sway predict occurrence of lateral ankle sprain?

    PubMed Central

    de Noronha, M; Refshauge, K M; Herbert, R D; Kilbreath, S L

    2006-01-01

    Prevention of ankle sprain, the most common sporting injury, is only possible once risk factors have been identified. Voluntary strength, proprioception, postural sway, and range of motion are possible risk factors. A systematic review was carried out to investigate these possiblities. Eligible studies were those with longitudinal design investigating ankle sprain in subjects aged ⩾15 years. The studies had to have measured range of motion, voluntary strength, proprioception, or postural sway before monitoring incidence of lateral ankle sprain. Dorsiflexion range strongly predicted risk of ankle sprain. Postural sway and possibly proprioception were also predictors. Therefore the preliminary evidence suggests that people with reduced ankle dorsiflexion range may be at increased risk of ankle sprain. PMID:16920769

  15. A method to reversibly degrade proprioceptive feedback in research on human motor control.

    PubMed

    Bock, Otmar; Pipereit, Katja; Mierau, Andreas

    2007-03-15

    In research on human motor skills, it is often desirable to manipulate proprioceptive feedback in order to determine its contribution towards subjects' performance. Here we evaluate an easy-to-use, non-invasive method to temporarily reduce proprioceptive responsiveness. Two physiotherapy vibrators contacted the distal end of the subjects' forearm on the flexor and extensor side; they were either turned off, or they vibrated at 80 Hz with an amplitude of 1mm. We found that vibration substantially impaired subjects' ability to use their hand in an angle matching, a force production and a haptic shape perception task. We also found that vibration strongly attenuated the H-reflex of the ipsilateral M. flexor carpi radialis. These results suggest that agonist-antagonist vibration is a useful method to degrade proprioceptive responsiveness for research on higher motor functions.

  16. Deficits in the ability to use proprioceptive feedback in children with hemiplegic cerebral palsy.

    PubMed

    Goble, Daniel J; Hurvitz, Edward A; Brown, Susan H

    2009-09-01

    Compared with motor impairment in children with hemiplegic cerebral palsy (CP), less attention has been paid to sensory feedback processing deficits. This includes, especially, proprioceptive information regarding arm position. This study examined the ability of children with hemiplegic CP to use proprioceptive feedback during a goal-directed target-matching task. Eight children with hemiplegic CP and eight typically developing children performed proprioceptively guided matching of elbow position with either arm. Between groups, it was found that matching errors were significantly greater for the affected arm of children with hemiplegic CP. With respect to the side of brain injury, deficits were only seen for children with right hemisphere damage. These results provide valuable information that may assist in the development of more effective sensorimotor rehabilitation and training paradigms. PMID:19318973

  17. Posing for awareness: proprioception modulates access to visual consciousness in a continuous flash suppression task.

    PubMed

    Salomon, Roy; Lim, Melanie; Herbelin, Bruno; Hesselmann, Guido; Blanke, Olaf

    2013-06-03

    The rules governing the selection of which sensory information reaches consciousness are yet unknown. Of our senses, vision is often considered to be the dominant sense, and the effects of bodily senses, such as proprioception, on visual consciousness are frequently overlooked. Here, we demonstrate that the position of the body influences visual consciousness. We induced perceptual suppression by using continuous flash suppression. Participants had to judge the orientation a target stimulus embedded in a task-irrelevant picture of a hand. The picture of the hand could either be congruent or incongruent with the participants' actual hand position. When the viewed and the real hand positions were congruent, perceptual suppression was broken more rapidly than during incongruent trials. Our findings provide the first evidence of a proprioceptive bias in visual consciousness, suggesting that proprioception not only influences the perception of one's own body and self-consciousness, but also visual consciousness.

  18. Self-Supervised Learning of Terrain Traversability from Proprioceptive Sensors

    NASA Technical Reports Server (NTRS)

    Bajracharya, Max; Howard, Andrew B.; Matthies, Larry H.

    2009-01-01

    Robust and reliable autonomous navigation in unstructured, off-road terrain is a critical element in making unmanned ground vehicles a reality. Existing approaches tend to rely on evaluating the traversability of terrain based on fixed parameters obtained via testing in specific environments. This results in a system that handles the terrain well that it trained in, but is unable to process terrain outside its test parameters. An adaptive system does not take the place of training, but supplements it. Whereas training imprints certain environments, an adaptive system would imprint terrain elements and the interactions amongst them, and allow the vehicle to build a map of local elements using proprioceptive sensors. Such sensors can include velocity, wheel slippage, bumper hits, and accelerometers. Data obtained by the sensors can be compared to observations from ranging sensors such as cameras and LADAR (laser detection and ranging) in order to adapt to any kind of terrain. In this way, it could sample its surroundings not only to create a map of clear space, but also of what kind of space it is and its composition. By having a set of building blocks consisting of terrain features, a vehicle can adapt to terrain that it has never seen before, and thus be robust to a changing environment. New observations could be added to its library, enabling it to infer terrain types that it wasn't trained on. This would be very useful in alien environments, where many of the physical features are known, but some are not. For example, a seemingly flat, hard plain could actually be soft sand, and the vehicle would sense the sand and avoid it automatically.

  19. Changes in sensory reweighting of proprioceptive information during standing balance with age and disease.

    PubMed

    Pasma, J H; Engelhart, D; Maier, A B; Schouten, A C; van der Kooij, H; Meskers, C G M

    2015-12-01

    With sensory reweighting, reliable sensory information is selected over unreliable information during balance by dynamically combining this information. We used system identification techniques to show the weight and the adaptive process of weight change of proprioceptive information during standing balance with age and specific diseases. Ten healthy young subjects (aged between 20 and 30 yr) and 44 elderly subjects (aged above 65 yr) encompassing 10 healthy elderly, 10 with cataract, 10 with polyneuropathy, and 14 with impaired balance, participated in the study. During stance, proprioceptive information of the ankles was disturbed by rotation of the support surface with specific frequency content where disturbance amplitude increased over trials. Body sway and reactive ankle torque were measured to determine sensitivity functions of these responses to the disturbance amplitude. Model fits resulted in a proprioceptive weight (changing over trials), time delay, force feedback, reflexive stiffness, and damping. The proprioceptive weight was higher in healthy elderly compared with young subjects and higher in elderly subjects with cataract and with impaired balance compared with healthy elderly subjects. Proprioceptive weight decreased with increasing disturbance amplitude; decrease was similar in all groups. In all groups, the time delay was higher and the reflexive stiffness was lower compared with young or healthy elderly subjects. In conclusion, proprioceptive information is weighted more with age and in patients with cataract and impaired balance. With age and specific diseases the time delay was higher and reflexive stiffness was lower. These results illustrate the opportunity to detect the underlying cause of impaired balance in the elderly with system identification.

  20. Manually controlled human balancing using visual, vestibular and proprioceptive senses involves a common, low frequency neural process

    PubMed Central

    Lakie, Martin; Loram, Ian D

    2006-01-01

    Ten subjects balanced their own body or a mechanically equivalent unstable inverted pendulum by hand, through a compliant spring linkage. Their balancing process was always characterized by repeated small reciprocating hand movements. These bias adjustments were an observable sign of intermittent alterations in neural output. On average, the adjustments occurred at intervals of ∼400 ms. To generate appropriate stabilizing bias adjustments, sensory information about body or load movement is needed. Subjects used visual, vestibular or proprioceptive sensation alone and in combination to perform the tasks. We first ask, is the time between adjustments (bias duration) sensory specific? Vision is associated with slow responses. Other senses involved with balance are known to be faster. Our second question is; does bias duration depend on sensory abundance? An appropriate bias adjustment cannot occur until unplanned motion is unambiguously perceived (a sensory threshold). The addition of more sensory data should therefore expedite action, decreasing the mean bias adjustment duration. Statistical analysis showed that (1) the mean bias adjustment duration was remarkably independent of the sensory modality and (2) the addition of one or two sensory modalities made a small, but significant, decrease in the mean bias adjustment duration. Thus, a threshold effect can alter only a very minor part of the bias duration. The bias adjustment duration in manual balancing must reflect something more than visual sensation and perceptual thresholds; our suggestion is that it is a common central motor planning process. We predict that similar processes may be identified in the control of standing. PMID:16959857

  1. Proprioceptive Training and Injury Prevention in a Professional Men's Basketball Team: A Six-Year Prospective Study.

    PubMed

    Riva, Dario; Bianchi, Roberto; Rocca, Flavio; Mamo, Carlo

    2016-02-01

    Single limb stance instability is a risk factor for lower extremity injuries. Therefore, the development of proprioception may play an important role in injury prevention. This investigation considered a professional basketball team for 6 years, integrating systematic proprioceptive activity in the training routine. The purpose was to assess the effectiveness of proprioceptive training programs based on quantifiable instability, to reduce ankle sprains, knee sprains, and low back pain through developing refined and long-lasting proprioceptive control. Fifty-five subjects were studied. In the first biennium (2004-2006), the preventive program consisted of classic proprioceptive exercises. In the second biennium (2006-2008), the proprioceptive training became quantifiable and interactive by means of electronic proprioceptive stations. In the third biennium (2008-2010), the intensity and the training volume increased while the session duration became shorter. Analysis of variance was used to analyze the differences in proprioceptive control between groups, years, and bienniums. Injury rates and rate ratios of injury during practices and games were estimated. The results showed a statistically significant reduction in the occurrence of ankle sprains by 81% from the first to the third biennium (p < 0.001). Low back pain showed similar results with a reduction of 77.8% (p < 0.005). The reduction in knee sprains was 64.5% (not significant). Comparing the third biennium with the level of all new entry players, proprioceptive control improved significantly by 72.2% (p < 0.001). These findings indicate that improvements in proprioceptive control in single stance may be a key factor for an effective reduction in ankle sprains, knee sprains, and low back pain.

  2. Slow light beam splitter.

    PubMed

    Xiao, Yanhong; Klein, Mason; Hohensee, Michael; Jiang, Liang; Phillips, David F; Lukin, Mikhail D; Walsworth, Ronald L

    2008-07-25

    We demonstrate a slow light beam splitter using rapid coherence transport in a wall-coated atomic vapor cell. We show that particles undergoing random and undirected classical motion can mediate coherent interactions between two or more optical modes. Coherence, written into atoms via electromagnetically induced transparency using an input optical signal at one transverse position, spreads out via ballistic atomic motion, is preserved by an antirelaxation wall coating, and is then retrieved in outgoing slow light signals in both the input channel and a spatially-separated second channel. The splitting ratio between the two output channels can be tuned by adjusting the laser power. The slow light beam splitter may improve quantum repeater performance and be useful as an all-optical dynamically reconfigurable router.

  3. Slowing heterosexual HIV transmission.

    PubMed

    Ronald, A R

    1995-06-01

    HIV-1 is spreading rapidly through heterosexual intercourse in many societies. Slowing the transmission of this virus is the most urgent global public health priority. Our understanding of the biologic differences between societies that account for most vacancies in heterosexual HIV transmission are now understood. Effective interventions to slow transmission must be designed, implemented, and evaluated. Human and fiscal resources must be provided through a shared global effort. The consequences of failing to do so will lead to a world catastrophe of unprecedented magnitude. PMID:7673667

  4. Proprioceptive acuity predicts muscle co-contraction of the tibialis anterior and gastrocnemius medialis in older adults' dynamic postural control.

    PubMed

    Craig, C E; Goble, D J; Doumas, M

    2016-05-13

    Older adults use a different muscle strategy to cope with postural instability, in which they 'co-contract' the muscles around the ankle joint. It has been suggested that this is a compensatory response to age-related proprioceptive decline however this view has never been assessed directly. The current study investigated the association between proprioceptive acuity and muscle co-contraction in older adults. We compared muscle activity, by recording surface electromyography (EMG) from the bilateral tibialis anterior (TA) and gastrocnemius medialis (GM) muscles, in young (aged 18-34) and older adults (aged 65-82) during postural assessment on a fixed and sway-referenced surface at age-equivalent levels of sway. We performed correlations between muscle activity and proprioceptive acuity, which was assessed using an active contralateral matching task. Despite successfully inducing similar levels of sway in the two age groups, older adults still showed higher muscle co-contraction. A stepwise regression analysis showed that proprioceptive acuity measured using variable error was the best predictor of muscle co-contraction in older adults. However, despite suggestions from previous research, proprioceptive error and muscle co-contraction were negatively correlated in older adults, suggesting that better proprioceptive acuity predicts more co-contraction. Overall, these results suggest that although muscle co-contraction may be an age-specific strategy used by older adults, it is not to compensate for age-related proprioceptive deficits.

  5. Proprioceptive acuity predicts muscle co-contraction of the tibialis anterior and gastrocnemius medialis in older adults' dynamic postural control.

    PubMed

    Craig, C E; Goble, D J; Doumas, M

    2016-05-13

    Older adults use a different muscle strategy to cope with postural instability, in which they 'co-contract' the muscles around the ankle joint. It has been suggested that this is a compensatory response to age-related proprioceptive decline however this view has never been assessed directly. The current study investigated the association between proprioceptive acuity and muscle co-contraction in older adults. We compared muscle activity, by recording surface electromyography (EMG) from the bilateral tibialis anterior (TA) and gastrocnemius medialis (GM) muscles, in young (aged 18-34) and older adults (aged 65-82) during postural assessment on a fixed and sway-referenced surface at age-equivalent levels of sway. We performed correlations between muscle activity and proprioceptive acuity, which was assessed using an active contralateral matching task. Despite successfully inducing similar levels of sway in the two age groups, older adults still showed higher muscle co-contraction. A stepwise regression analysis showed that proprioceptive acuity measured using variable error was the best predictor of muscle co-contraction in older adults. However, despite suggestions from previous research, proprioceptive error and muscle co-contraction were negatively correlated in older adults, suggesting that better proprioceptive acuity predicts more co-contraction. Overall, these results suggest that although muscle co-contraction may be an age-specific strategy used by older adults, it is not to compensate for age-related proprioceptive deficits. PMID:26905952

  6. Immediate effect of stretching and ultrasound on hamstring flexibility and proprioception.

    PubMed

    Cho, Sung-Hak; Kim, Soo-Han

    2016-06-01

    [Purpose] This research explored the positive effects of self-myofascial release on hamstring muscular flexibility and proprioception and investigated the effectiveness of the stretch combined with therapeutic ultrasound. [Subjects and Methods] This study included 30 healthy university students with no history of pain in the Achilles tendon or hamstring within the recent 6 months. Each participant completed two experiments. In the first experiment (MS), they completed self-myofascial stretching using a foam roller for 7 days. In the second experiment (MSU), the same participants performed the self-myofascial stretching after the 15-minute application of ultrasound. This study involved a pre- and post-test on hamstring muscle flexibility and hip joint proprioception. [Results] The use of self-myofascial stretching in the MS experiment had a significant effect on hamstring muscle flexibility and hip joint proprioception. However, the addition of ultrasound in the MSU experiment had no additive effect. [Conclusion] Self-myofascial stretching immediately increased hamstring muscle flexibility and improved hip joint proprioception, but the addition of pre-stretch ultra sound provided no further benefit.

  7. Immediate effect of stretching and ultrasound on hamstring flexibility and proprioception

    PubMed Central

    Cho, Sung-Hak; Kim, Soo-Han

    2016-01-01

    [Purpose] This research explored the positive effects of self-myofascial release on hamstring muscular flexibility and proprioception and investigated the effectiveness of the stretch combined with therapeutic ultrasound. [Subjects and Methods] This study included 30 healthy university students with no history of pain in the Achilles tendon or hamstring within the recent 6 months. Each participant completed two experiments. In the first experiment (MS), they completed self-myofascial stretching using a foam roller for 7 days. In the second experiment (MSU), the same participants performed the self-myofascial stretching after the 15-minute application of ultrasound. This study involved a pre- and post-test on hamstring muscle flexibility and hip joint proprioception. [Results] The use of self-myofascial stretching in the MS experiment had a significant effect on hamstring muscle flexibility and hip joint proprioception. However, the addition of ultrasound in the MSU experiment had no additive effect. [Conclusion] Self-myofascial stretching immediately increased hamstring muscle flexibility and improved hip joint proprioception, but the addition of pre-stretch ultra sound provided no further benefit. PMID:27390420

  8. Different Effects of Numerical Magnitude on Visual and Proprioceptive Reference Frames

    PubMed Central

    Blini, Elvio; Cattaneo, Zaira; Vallar, Giuseppe

    2013-01-01

    This study assessed whether numerical magnitude affects the setting of basic spatial coordinates and reference frames, namely the subjective straight ahead. Three tasks were given to 24 right-handed healthy participants: a proprioceptive and a visuo-proprioceptive task, requiring pointing to the subjective straight ahead, and a visual task, requiring a perceptual judgment about the straight ahead position of a light moving left-to-right, or right-to-left. A control task, requiring the bisection of rods of different lengths, was also given. The four tasks were performed under conditions of passive auditory numerical (i.e., listening to small, “2,” and large, “8,” numbers), and neutral auditory-verbal (“blah”) stimulation. Numerical magnitude modulated the participants’ deviations in the visual straight ahead task, when the movement of the light was from left-to-right, with the small number bringing about a leftward deviation, the large number a rightward deviation. A similar directional modulation was found in the rod bisection task, in line with previous evidence. No effects of numerical magnitude were found on the proprioceptive and visuo-proprioceptive straight ahead tasks. These results suggest that the spatial effects induced by the activation of the mental number line extend to an egocentric frame of reference but only when a portion of horizontal space has to be “actively” explored. PMID:23616777

  9. Immediate effect of stretching and ultrasound on hamstring flexibility and proprioception.

    PubMed

    Cho, Sung-Hak; Kim, Soo-Han

    2016-06-01

    [Purpose] This research explored the positive effects of self-myofascial release on hamstring muscular flexibility and proprioception and investigated the effectiveness of the stretch combined with therapeutic ultrasound. [Subjects and Methods] This study included 30 healthy university students with no history of pain in the Achilles tendon or hamstring within the recent 6 months. Each participant completed two experiments. In the first experiment (MS), they completed self-myofascial stretching using a foam roller for 7 days. In the second experiment (MSU), the same participants performed the self-myofascial stretching after the 15-minute application of ultrasound. This study involved a pre- and post-test on hamstring muscle flexibility and hip joint proprioception. [Results] The use of self-myofascial stretching in the MS experiment had a significant effect on hamstring muscle flexibility and hip joint proprioception. However, the addition of ultrasound in the MSU experiment had no additive effect. [Conclusion] Self-myofascial stretching immediately increased hamstring muscle flexibility and improved hip joint proprioception, but the addition of pre-stretch ultra sound provided no further benefit. PMID:27390420

  10. Upper Limb Asymmetries in the Perception of Proprioceptively Determined Dynamic Position Sense

    ERIC Educational Resources Information Center

    Goble, Daniel J.; Brown, Susan H.

    2010-01-01

    Recent studies of position-related proprioceptive sense have provided evidence of a nonpreferred left arm advantage in right-handed individuals. The present study sought to determine whether similar asymmetries might exist in "dynamic position" sense. Thirteen healthy, right-handed adults were blindfolded and seated with arms placed on…

  11. Developmental changes in the visual-proprioceptive integration threshold of children.

    PubMed

    Jaime, Mark; Longard, Julie; Moore, Chris

    2014-09-01

    The ability to detect artificially induced visual-proprioceptive asynchrony reflects an awareness of the first-person experience of self-generated movement. The current study assessed children's (5- to 8-year-olds) and adults' ability to integrate asynchronous visual and proprioceptive stimulation by delaying the visual feedback of self-generated action in videos. Children and adults observed a monitor showing their movements of a joystick at varying delay durations and were then asked to make judgments on whether their movements appeared to be delayed or live. Children demonstrated age-related differences in their reporting of delay judgments across all delay conditions. Adults' performances on the same task exceeded those of children. The results of this study provide a mapping of visual-proprioceptive integration abilities in 5 to 8 year old children. The age-related increase in sensitivity to visual-proprioceptive asynchrony is suggestive of increasing sensitivity to the temporal properties of multisensory feedback of self-generated movement with development.

  12. Infant Reactivity to Redundant Proprioceptive and Auditory Stimulation: A Twin Study.

    ERIC Educational Resources Information Center

    Van den Daele, Leland D.

    The role of genetic factors in infant response to redundancy was evaluated through observation of the behavior of three sets of same-sex fraternal twins and six sets of same-sex identical twins to combinations of redundant proprioceptive and auditory stimulation. The twins ranged in age from 6 weeks to 24 weeks. One member of each twin set was…

  13. Proprioceptive Neuromuscular Facilitation Flexibility Techniques: Acute Effects on Arterial Blood Pressure.

    ERIC Educational Resources Information Center

    Cornelius, William L.; Craft-Hamm, Kelley

    1988-01-01

    The effects of stretching techniques on arterial blood pressure (ABP) were studied in three groups of 20 men each. Each group performed one of three proprioceptive neuromuscular facilitation (PNF) techniques. Results are presented. The study indicates that the benefits of stretching may outweigh the risk of elevated ABP. (JL)

  14. The mirror illusion: does proprioceptive drift go hand in hand with sense of agency?

    PubMed

    Tajima, Daisuke; Mizuno, Tota; Kume, Yuichiro; Yoshida, Takako

    2015-01-01

    Vection can be regarded as the illusion of "whole-body" position perception. In contrast, the mirror illusion is that of "body-part" position perception. When participants viewed their left hands in a mirror positioned along the midsaggital axis while moving both hands synchronously, they hardly noticed the spatial offset between the hand in the mirror and the obscured real right hand. This illusion encompasses two phenomena: proprioceptive drift and sense of agency. Proprioceptive drift represented a perceptual change in the position of the obscured hand relative to that of the hand in the mirror. Sense of agency referred to the participants' subjective sense of controlling body image as they would their own bodies. We examined the spatial offset between these two phenomena. Participants responded to a two-alternative forced choice (2AFC) question regarding the subjective position of their right hands and questionnaires regarding sense of agency at various positions of the right hand. We analyzed the 2AFC data using a support vector machine and compared its classification result and the questionnaire results. Our data analysis suggested that the two phenomena were observed in concentric space, but the estimated range of the proprioceptive drift was slightly narrower than the range of agency. Although this outcome can be attributed to differences in measurement or analysis, to our knowledge, this is the first report to suggest that proprioceptive drift and sense of agency are concentric and almost overlap.

  15. Mobile Phone-Based Joint Angle Measurement for Functional Assessment and Rehabilitation of Proprioception

    PubMed Central

    Mourcou, Quentin; Fleury, Anthony; Diot, Bruno; Franco, Céline; Vuillerme, Nicolas

    2015-01-01

    Assessment of joint functional and proprioceptive abilities is essential for balance, posture, and motor control rehabilitation. Joint functional ability refers to the capacity of movement of the joint. It may be evaluated thereby measuring the joint range of motion (ROM). Proprioception can be defined as the perception of the position and of the movement of various body parts in space. Its role is essential in sensorimotor control for movement acuity, joint stability, coordination, and balance. Its clinical evaluation is commonly based on the assessment of the joint position sense (JPS). Both ROM and JPS measurements require estimating angles through goniometer, scoliometer, laser-pointer, and bubble or digital inclinometer. With the arrival of Smartphones, these costly clinical tools tend to be replaced. Beyond evaluation, maintaining and/or improving joint functional and proprioceptive abilities by training with physical therapy is important for long-term management. This review aims to report Smartphone applications used for measuring and improving functional and proprioceptive abilities. It identifies that Smartphone applications are reliable for clinical measurements and are mainly used to assess ROM and JPS. However, there is lack of studies on Smartphone applications which can be used in an autonomous way to provide physical therapy exercises at home. PMID:26583101

  16. The Rubber Hand Illusion Reveals Proprioceptive and Sensorimotor Differences in Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Paton, Bryan; Hohwy, Jakob; Enticott, Peter G.

    2012-01-01

    Autism spectrum disorder (ASD) is characterised by differences in unimodal and multimodal sensory and proprioceptive processing, with complex biases towards local over global processing. Many of these elements are implicated in versions of the rubber hand illusion (RHI), which were therefore studied in high-functioning individuals with ASD and a…

  17. Effects of proprioception training with exercise imagery on balance ability of stroke patients

    PubMed Central

    Lee, Hyungjin; Kim, Heesoo; Ahn, Myunghwan; You, Youngyoul

    2015-01-01

    [Purpose] The purpose of the present study was to examine and compare the effects of proprioceptive training accompanied by motor imagery training and general proprioceptive training on the balance of stroke patients. [Subjects and Methods] Thirty-six stroke patients were randomly assigned to either an experimental group of 18 patients or a control group of 18 patients. The experimental group was given motor imagery training for 5 minutes and proprioceptive training for 25 minutes, while the control group was given proprioceptive training for 30 minutes. Each session and training program was implemented 5 times a week for 8 weeks. The Korean version of the Berg Balance Scale (K-BBS), Timed Up and Go test (TUG), weight bearing ratio (AFA-50, Alfoots, Republic of Korea), and joint position sense error (Dualer IQ Inclinometer, JTECH Medical, USA) were measured. [Results] Both groups showed improvements in K-BBS, TUG, weight bearing ratio, and joint position sense error. The measures of the experimental group showed greater improvement than the control group. [Conclusion] Motor imagery training, which is not subject to time restrictions, is not very risky and can be used as an effective treatment method for improving the balance ability of stroke patients. PMID:25642023

  18. Changes in proprioception and pain in patients with neck pain after upper thoracic manipulation

    PubMed Central

    Yang, Jinmo; Lee, Byoungkwon; Kim, Changbeom

    2015-01-01

    [Purpose] The purpose of this study was to conduct cervical stability training and upper thoracic manipulation for patients with chronic neck pain and then investigate the changes of cervical proprioception and pain. [Subjects and Methods] Subjects were 30 workers with mechanical neck pain, who were randomly divided into an upper thoracic manipulation group and a cervical stability training group. Upper thoracic manipulation after cervical stability training was conducted for the upper thoracic manipulation group, and only stability training was conducted for the cervical stability training group. The intervention period was six weeks, and consisted of three sessions a week, each of which lasted for 30 minutes. For proprioception measurement, an electro-goniometer was used to measure reposition sense before and after the intervention. The visual analogue scale was used to assess pain. [Results] After the intervention, the error angle was significantly smaller in flexion and right left side-bending, and pain was significantly reduced in the upper thoracic manipulation group. According to the post intervention comparison of the two groups, there were significant differences in the proprioception and pain values. [Conclusion] Conducting both cervical stability training and upper thoracic manipulation for patients with chronic neck pain was more helpful for the improvement of proprioception and pain than cervical stability training alone. PMID:25931733

  19. Development of the Comprehensive Observations of Proprioception (COP): Validity, Reliability, and Factor Analysis

    PubMed Central

    Blanche, Erna Imperatore; Bodison, Stefanie; Chang, Megan C.; Reinoso, Gustavo

    2013-01-01

    OBJECTIVE We developed an observational tool, the Comprehensive Observations of Proprioception (COP), for identifying proprioceptive processing issues in children with developmental disabilities. METHOD Development of the COP underwent three phases. First, we developed items representing proprioceptive functions on the basis of an extensive literature review and consultation with occupational therapists. We then established interrater reliability and content, construct, and criterion validity. Finally, we completed a factor analysis of COP ratings of 130 children with known developmental disabilities. RESULTS Adequate validity and reliability were established. Factor analysis revealed a four-factor model that explained the underlying structure of the measure as it was hypothesized. CONCLUSION The COP is a valid criterion-referenced short observational tool that structures the clinician’s observations by linking a child’s behaviors to areas identified in the literature as relevant to proprioceptive processing. It takes 15 min to administer and can be used in a variety of contexts, such as the home, clinic, and school. PMID:23106989

  20. Time Course of Reach Adaptation and Proprioceptive Recalibration during Visuomotor Learning

    PubMed Central

    Ruttle, Jennifer E.; Cressman, Erin K.; ’t Hart, Bernard Marius; Henriques, Denise Y. P.

    2016-01-01

    Training to reach with rotated visual feedback results in adaptation of hand movements, which persist when the perturbation is removed (reach aftereffects). Training also leads to changes in felt hand position, which we refer to as proprioceptive recalibration. The rate at which motor and proprioceptive changes develop throughout training is unknown. Here, we aim to determine the timescale of these changes in order to gain insight into the processes that may be involved in motor learning. Following six rotated reach training trials (30° rotation), at three radially located targets, we measured reach aftereffects and perceived hand position (proprioceptive guided reaches). Participants trained with opposing rotations one week apart to determine if the original training led to any retention or interference. Results suggest that both motor and proprioceptive recalibration occurred in as few as six rotated-cursor training trials (7.57° & 3.88° respectively), with no retention or interference present one week after training. Despite the rapid speed of both motor and sensory changes, these shifts do not saturate to the same degree. Thus, different processes may drive these changes and they may not constitute a single implicit process. PMID:27732595

  1. Micro movements of the upper limb in fibromyalgia: The relation to proprioceptive accuracy and visual feedback.

    PubMed

    Bardal, Ellen Marie; Roeleveld, Karin; Ihlen, Espen; Mork, Paul Jarle

    2016-02-01

    The purpose of this study was to explore the role of visual and proprioceptive feedback in upper limb posture control in fibromyalgia (FM) and to assess the coherence between acceleration measurements of upper limb micro movements and surface electromyography (sEMG) of shoulder muscle activity (upper trapezius and deltoid). Twenty-five female FM patients and 25 age- and sex-matched healthy controls (HCs) performed three precision motor tasks: (1) maintain a steady shoulder abduction angle of 45° while receiving visual feedback about upper arm position and supporting external loads (0.5, 1, or 2kg), (2) maintain the same shoulder abduction angle without visual feedback (eyes closed) and no external loading, and (3) a joint position sense test (i.e., assessment of proprioceptive accuracy). Patients had more extensive increase in movement variance than HCs when visual feedback was removed (P<0.03). Proprioceptive accuracy was related to movement variance in HCs (R⩾0.59, P⩽0.002), but not in patients (R⩽0.25, P⩾0.24). There was no difference between patients and HCs in coherence between sEMG and acceleration data. These results may indicate that FM patients are more dependent on visual feedback and less reliant on proprioceptive information for upper limb posture control compared to HCs.

  2. Mobile Phone-Based Joint Angle Measurement for Functional Assessment and Rehabilitation of Proprioception.

    PubMed

    Mourcou, Quentin; Fleury, Anthony; Diot, Bruno; Franco, Céline; Vuillerme, Nicolas

    2015-01-01

    Assessment of joint functional and proprioceptive abilities is essential for balance, posture, and motor control rehabilitation. Joint functional ability refers to the capacity of movement of the joint. It may be evaluated thereby measuring the joint range of motion (ROM). Proprioception can be defined as the perception of the position and of the movement of various body parts in space. Its role is essential in sensorimotor control for movement acuity, joint stability, coordination, and balance. Its clinical evaluation is commonly based on the assessment of the joint position sense (JPS). Both ROM and JPS measurements require estimating angles through goniometer, scoliometer, laser-pointer, and bubble or digital inclinometer. With the arrival of Smartphones, these costly clinical tools tend to be replaced. Beyond evaluation, maintaining and/or improving joint functional and proprioceptive abilities by training with physical therapy is important for long-term management. This review aims to report Smartphone applications used for measuring and improving functional and proprioceptive abilities. It identifies that Smartphone applications are reliable for clinical measurements and are mainly used to assess ROM and JPS. However, there is lack of studies on Smartphone applications which can be used in an autonomous way to provide physical therapy exercises at home. PMID:26583101

  3. Perceptual distortion of intrapersonal and near-personal space sensed by proprioception.

    PubMed

    Naito, Eiichi

    2002-04-01

    It is known that the illusory displacement of a vibrated limb can be transferred to a nonvibrated contacted limb. The purpose of this study was to quantify and compare the transferred illusory displacements occurring in the intrapersonal and near-personal space. In two tasks, 8 male and 8 female blindfolded subjects estimated (1) the height of the left elbow and (2) the height of an external object located at the same height as the left elbow, by the proprioception of the right arm which was Subject to illusory displacement. If the internal representation of the left elbow in one's body schema could provide precise information of its static position independently of the proprioception of the right arm, the perceived displacement of the right arm might be smaller when influenced by proprioceptive information from the static left arm, than when in contrast instead with an object which is not a body part. There was no difference in the estimation of illusory displacement between male and female subjects and between right and left arms. No significant difference was observed between transferred displacements of the left elbow and the object. This means that the perception of limb position sensed by the proprioception of another limb can be distorted as easily as the perception of location of an external object. This suggests that the internal representation of static limb position is not enough to provide the correct information of current limb position in the absence of vision.

  4. Do Gravity-Related Sensory Information Enable the Enhancement of Cortical Proprioceptive Inputs When Planning a Step in Microgravity?

    PubMed Central

    Saradjian, Anahid H.; Paleressompoulle, Dany; Louber, Didier; Coyle, Thelma; Blouin, Jean; Mouchnino, Laurence

    2014-01-01

    We recently found that the cortical response to proprioceptive stimulation was greater when participants were planning a step than when they stood still, and that this sensory facilitation was suppressed in microgravity. The aim of the present study was to test whether the absence of gravity-related sensory afferents during movement planning in microgravity prevented the proprioceptive cortical processing to be enhanced. We reestablished a reference frame in microgravity by providing and translating a horizontal support on which the participants were standing and verified whether this procedure restored the proprioceptive facilitation. The slight translation of the base of support (lateral direction), which occurred prior to step initiation, stimulated at least cutaneous and vestibular receptors. The sensitivity to proprioceptive stimulation was assessed by measuring the amplitude of the cortical somatosensory-evoked potential (SEP, over the Cz electrode) following the vibration of the leg muscle. The vibration lasted 1 s and the participants were asked to either initiate a step at the vibration offset or to remain still. We found that the early SEP (90–160 ms) was smaller when the platform was translated than when it remained stationary, revealing the existence of an interference phenomenon (i.e., when proprioceptive stimulation is preceded by the stimulation of different sensory modalities evoked by the platform translation). By contrast, the late SEP (550 ms post proprioceptive stimulation onset) was greater when the translation preceded the vibration compared to a condition without pre-stimulation (i.e., no translation). This suggests that restoring a body reference system which is impaired in microgravity allowed a greater proprioceptive cortical processing. Importantly, however, the late SEP was similarly increased when participants either produced a step or remained still. We propose that the absence of step-induced facilitation of proprioceptive cortical

  5. Do gravity-related sensory information enable the enhancement of cortical proprioceptive inputs when planning a step in microgravity?

    PubMed

    Saradjian, Anahid H; Paleressompoulle, Dany; Louber, Didier; Coyle, Thelma; Blouin, Jean; Mouchnino, Laurence

    2014-01-01

    We recently found that the cortical response to proprioceptive stimulation was greater when participants were planning a step than when they stood still, and that this sensory facilitation was suppressed in microgravity. The aim of the present study was to test whether the absence of gravity-related sensory afferents during movement planning in microgravity prevented the proprioceptive cortical processing to be enhanced. We reestablished a reference frame in microgravity by providing and translating a horizontal support on which the participants were standing and verified whether this procedure restored the proprioceptive facilitation. The slight translation of the base of support (lateral direction), which occurred prior to step initiation, stimulated at least cutaneous and vestibular receptors. The sensitivity to proprioceptive stimulation was assessed by measuring the amplitude of the cortical somatosensory-evoked potential (SEP, over the Cz electrode) following the vibration of the leg muscle. The vibration lasted 1 s and the participants were asked to either initiate a step at the vibration offset or to remain still. We found that the early SEP (90-160 ms) was smaller when the platform was translated than when it remained stationary, revealing the existence of an interference phenomenon (i.e., when proprioceptive stimulation is preceded by the stimulation of different sensory modalities evoked by the platform translation). By contrast, the late SEP (550 ms post proprioceptive stimulation onset) was greater when the translation preceded the vibration compared to a condition without pre-stimulation (i.e., no translation). This suggests that restoring a body reference system which is impaired in microgravity allowed a greater proprioceptive cortical processing. Importantly, however, the late SEP was similarly increased when participants either produced a step or remained still. We propose that the absence of step-induced facilitation of proprioceptive cortical

  6. Knee-joint proprioception during 30-day 6 degrees head-down bed rest with isotonic and isokinetic exercise training

    NASA Technical Reports Server (NTRS)

    Bernauer, E. M.; Walby, W. F.; Ertl, A. C.; Dempster, P. T.; Bond, M.; Greenleaf, J. E.

    1994-01-01

    To determine if daily isotonic exercise or isokinetic exercise training coupled with daily leg proprioceptive training, would influence leg proprioceptive tracking responses during bed rest (BR), 19 men (36 +/- SD 4 years, 178 +/- 7 cm, 76.8 +/- 7.8 kg) were allocated into a no-exercise (NOE) training control group (n = 5), and isotonic exercise (ITE, n = 7) and isokinetic exercise (IKE, n = 7) training groups. Exercise training was conducted during BR for two 30-min periods.d-1, 5 d.week-1. Only the IKE group performed proprioceptive training using a new isokinetic procedure with each lower extremity for 2.5 min before and after the daily exercise training sessions; proprioceptive testing occurred weekly for all groups. There were no significant differences in proprioceptive tracking scores, expressed as a percentage of the perfect score of 100, in the pre-BR ambulatory control period between the three groups. Knee extension and flexion tracking responses were unchanged with NOE during BR, but were significantly greater (*p < 0.05) at the end of BR in both exercise groups when compared with NOE responses (extension: NOE 80.7 +/- 0.7%, ITE 82.9* +/- 0.6%, IKE 86.5* +/- 0.7%; flexion: NOE 77.6 +/- 1.5%, ITE 80.0 +/- 0.8% (NS), IKE 83.6* +/- 0.8%). Although proprioceptive tracking was unchanged during BR with NOE, both isotonic exercise training (without additional proprioceptive training) and especially isokinetic exercise training when combined with daily proprioceptive training, significantly improved knee proprioceptive tracking responses after 30 d of BR.

  7. The effect of visuomotor adaptation on proprioceptive localization: the contributions of perceptual and motor changes.

    PubMed

    Clayton, Holly A; Cressman, Erin K; Henriques, Denise Y P

    2014-07-01

    Reaching movements are rapidly adapted following training with rotated visual feedback of the hand (motor recalibration). Our laboratory has also found that visuomotor adaptation results in changes in estimates of felt hand position (proprioceptive recalibration) in the direction of the visuomotor distortion (Cressman and Henriques 2009, 2010; Cressman et al. 2010). In the present study, we included an additional method for measuring hand proprioception [specifically, proprioceptive-guided reaches of the unadapted (left) hand to the robot-guided adapted (right) hand-target] and compared this with our original perceptual task (estimating the felt hand position of the adapted hand relative to visual reference markers/the body midline), as well as to no-cursor reaches with the adapted hand (reaching to visual and midline-targets), to better identify whether changes in reaching following adaptation to a 50° rightward-rotated cursor reflect sensory or motor processes. Results for the proprioceptive estimation task were consistent with previous findings; subjects felt their hand to be aligned with a reference marker when it was shifted approximately 4° more in the direction of the visuomotor distortion following adaptation compared with baseline conditions. Moreover, we found similar changes in the proprioceptive-guided reaching task such that subjects misreached 5° in the direction of the cursor rotation. However, these results were true only for proprioceptive-guided reaches to the adapted hand, as reaches to the body midline were not affected by adaptation. This suggests that proprioceptive recalibration is restricted to the adapted hand and does not generalize to the rest of the body; this truly reflects a change in the sensory representation of the hand rather than changes in the motor program. This is in contrast to no-cursor reaches made with the adapted hand, which show reach after-effects for both visual targets and the midline, suggesting that reaches with

  8. The Role of Limb Torque, Muscle Action and Proprioception During Closed Kinetic Chain Rehabilitation of The Lower Extremity

    PubMed Central

    Bunton, Edwin E.; Pitney, William A.; Cappaert, Thomas A.; Kane, Alexander W.

    1993-01-01

    This paper defines the differences between open and closed kinetic chain exercise and explains the role of limb torque, muscle action, and proprioception during rehabilitation of the lower extremity. Closed kinetic chain rehabilitation is shown to decrease shear forces, increase proprioception, and increase muscle group coordination through examples of progressive exercises. The authors conclude that closed kinetic chain rehabilitation is an economical, efficient, and effective means of rehabilitation, with the ultimate goal of enhancing proprioception, thus gaining lower extremity joint stability. ImagesFig 9a-b.Fig 1.Fig 2.Fig 3a-b.Fig 4a-b.Fig 5.Fig 6.Fig 7.Fig 8. PMID:16558197

  9. Putative proprioceptive function of the pelvic ligaments: biomechanical and histological studies.

    PubMed

    Varga, Endre; Dudas, Bertalan; Tile, Marvin

    2008-08-01

    The sacrospinous (SS) and sacrotuberous (ST) ligaments of the pelvic ring are known as mechanical stabilisers of the pelvic girdle, primarily against rotational forces in the sagittal and horizontal planes. Earlier studies, however, raised the possibility that ST/SS ligaments possess significant proprioceptive function, while the mechanical role of these ligaments in maintaining the structural integrity of the pelvis is of less importance. The aim of this study is to determine whether the function of these ligaments is strictly to provide mechanical stability or if they have any additional functional properties, i.e., proprioception. In order to reveal the function of the SS/ST ligaments, biomechanical studies of cadaver pelvis were used along with the histological analysis of the ligaments. Following measurements to determine the accurate mechanical role of the pelvic ligaments, the strength of these ligaments was significantly less than we earlier expected. For this reason other functions of the SS/ST ligaments were considered, including the proprioceptive role. Indeed, histological studies revealed ramifying nerve terminals in the SS/ST ligaments. These terminals may represent the morphological substrate of the proprioceptive function associated with the ligaments. Our studies revealed that SS/ST ligaments might have a significant proprioceptive function providing information of the position of the pelvis. Consequently, the mechanical role of the ligaments in maintaining the structural integrity of the pelvis may be significantly less than previously assumed. Understanding the function of the SS/ST ligaments is crucial for providing more precise guidelines for patient management with injuries to the posterior pelvic region.

  10. Quantitative analysis of locomotor defects in neonatal mice lacking proprioceptive feedback

    PubMed Central

    Dallman, Marisela A.; Ladle, David R.

    2013-01-01

    Proprioceptive feedback derived from specialized receptors in skeletal muscle is critical in forming an accurate map of limb position in space, and is used by the central nervous system to plan future movements and to determine accuracy of executed movements. Knockout mouse strains for genes expressed by proprioceptive sensory neurons have been generated that result in generalized motor deficits, but these deficits have not been quantitatively characterized. Here we characterize a conditional knockout mouse model where proprioceptive sensory neuron synaptic transmission has been blocked by selective ablation of munc18-1, a synaptic vesicle associated protein required for fusion of synaptic vesicles with the plasma membrane. Proprioceptive munc18-1 conditional mutants are impaired in surface righting—a dynamic postural adjustment task—and display several specific deficits in pivoting, an early locomotor behavior. Before the emergence of forward locomotion during postnatal development, animals explore their surroundings through pivoting, or rotating the upper torso around the relatively immobile base of the hind limbs. 3-D kinematic analysis was used to quantitatively describe this pivoting behavior at postnatal days 5 and 8 in control and munc18-1 conditional mutants. Mutant animals also pivot, but demonstrate alterations in movement strategy and in postural placement of the forelimbs during pivoting when compared to controls. In addition, brief forelimb stepping movements associated with pivoting are altered in mutant animals. Step duration and step height is increased in mutant animals. These results underscore the importance of proprioceptive feedback even at early stages in postnatal development. PMID:23911806

  11. Reliable and Rapid Robotic Assessment of Wrist Proprioception Using a Gauge Position Matching Paradigm

    PubMed Central

    Rinderknecht, Mike D.; Popp, Werner L.; Lambercy, Olivier; Gassert, Roger

    2016-01-01

    Quantitative assessments of position sense are essential for the investigation of proprioception, as well as for diagnosis, prognosis and treatment planning for patients with somatosensory deficits. Despite the development and use of various paradigms and robotic tools, their clinimetric properties are often poorly evaluated and reported. A proper evaluation of the latter is essential to compare results between different studies and to identify the influence of possible confounds on outcome measures. The aim of the present study was to perform a comprehensive evaluation of a rapid robotic assessment of wrist proprioception using a passive gauge position matching task. Thirty-two healthy subjects undertook six test-retests of proprioception of the right wrist on two different days. The constant error (CE) was 0.87°, the absolute error (AE) was 5.87°, the variable error (VE) was 4.59° and the total variability (E) was 6.83° in average for the angles presented in the range from 10° to 30°. The intraclass correlation analysis provided an excellent reliability for CE (0.75), good reliability for AE (0.68) and E (0.68), and fair reliability for VE (0.54). Tripling the assessment length had negligible effects on the reliabilities. Additional analysis revealed significant trends of larger overestimation (constant errors), as well as larger absolute and variable errors with increased flexion angles. No proprioceptive learning occurred, despite increased familiarity with the task, which was reflected in significantly decreased assessment duration by 30%. In conclusion, the proposed automated assessment can provide sensitive and reliable information on proprioceptive function of the wrist with an administration time of around 2.5 min, demonstrating the potential for its application in research or clinical settings. Moreover, this study highlights the importance of reporting the complete set of errors (CE, AE, VE, and E) in a matching experiment for the identification of

  12. Proprioceptive deficits of the lower limb following anterior cruciate ligament deficiency affect whole body steering control.

    PubMed

    Reed-Jones, Rebecca J; Vallis, Lori Ann

    2007-09-01

    The role of lower limb proprioception in the steering control of locomotion is still unclear. The purpose of the current study was to determine whether steering control is altered in individuals with reduced lower limb proprioception. Anterior cruciate ligament deficiency (ACLD) results in a decrease in proprioceptive information from the injured knee joint (Barrack et al. 1989). Therefore the whole body kinematics were recorded for eight unilateral ACLD individuals and eight CONTROL individuals during the descent of a 20 degrees incline ramp followed by either a redirection using a side or cross cutting maneuver or a continuation straight ahead. Onset of head and trunk yaw, mediolateral displacement of a weighted center of mass (COM(HT)) and mediolateral displacement of the swing foot were analyzed to evaluate differences in the steering control. Timing analyses revealed that ACLD individuals delayed the reorientation of body segments compared to CONTROL individuals. In addition, ACLD did not use a typical steering synergy where the head leads whole body reorientation; rather ACLD individuals reoriented the head, trunk and COM(HT) in the new direction at the same time. These results suggest that when lower limb proprioceptive information is reduced, the central nervous system (CNS) may delay whole body reorientation to the new travel direction, perhaps in order to integrate existing sensory information (vision, vestibular and proprioception) with the reduced information from the injured knee joint. This control strategy is maintained when visual information is present or reduced in a low light environment. Additionally, the CNS may move the head and trunk segments as, effectively, one segment to decrease the number of degrees of freedom that must be controlled and increase whole body stability during the turning task.

  13. Effects of proprioceptive circuit exercise on knee joint pain and muscle function in patients with knee osteoarthritis.

    PubMed

    Ju, Sung-Bum; Park, Gi Duck; Kim, Sang-Soo

    2015-08-01

    [Purpose] This study applied proprioceptive circuit exercise to patients with degenerative knee osteoarthritis and examined its effects on knee joint muscle function and the level of pain. [Subjects] In this study, 14 patients with knee osteoarthritis in two groups, a proprioceptive circuit exercise group (n = 7) and control group (n = 7), were examined. [Methods] IsoMed 2000 (D&R Ferstl GmbH, Hemau, Germany) was used to assess knee joint muscle function, and a Visual Analog Scale was used to measure pain level. [Results] In the proprioceptive circuit exercise group, knee joint muscle function and pain levels improved significantly, whereas in the control group, no significant improvement was observed. [Conclusion] A proprioceptive circuit exercise may be an effective way to strengthen knee joint muscle function and reduce pain in patients with knee osteoarthritis.

  14. Quantum gravity slows inflation

    SciTech Connect

    Tsamis, N.C. |; Woodard, R.P.

    1996-02-01

    We consider the quantum gravitational back-reaction on an initially inflating, homogeneous and isotropic universe whose topology is T{sup 3} {times} {Re}. Although there is no secular effect at one loop, an explicit calculation shows that two-loop processes act to slow the rate of expansion by an amount which becomes non-pertubatively large at late times. By exploiting Feynman`s tree theorem we show that all higher loops act in the same sense. 18 refs., 1 fig.

  15. Go, Slow, and Whoa Foods

    MedlinePlus

    ... quick tips for seasonal health, safety and fun Go, Slow, and Whoa Foods Past Issues / Summer 2007 ... of California and Flaghouse, Inc. 2002 Food Group GO Almost anytime foods SLOW Sometimes foods WHOA Once ...

  16. The effect of instability training on knee joint proprioception and core strength.

    PubMed

    Cuğ, Mutlu; Ak, Emre; Ozdemir, Recep Ali; Korkusuz, Feza; Behm, David G

    2012-01-01

    Although there are many studies demonstrating increased trunk activation under unstable conditions, it is not known whether this increased activation would translate into meaningful trunk strength with a prolonged training program. Additionally, while balance-training programs have been shown to improve stability, their effect on specific joint proprioception is not clear. Thus the objective of this study was to examine training adaptations associated with a 10-week instability-training program. Participants were tested pre- and post-training for trunk extension and flexion strength and knee proprioception. Forty-three participants participated in either a 10-week (3 days per week) instability-training program using Swiss balls and body weight as resistance or a control group (n = 17). The trained group increased (p < 0. 05) trunk extension peak torque/body weight (23.6%) and total work output (20.1%) from pre- to post-training while the control group decreased by 6.8% and 6.7% respectively. The exercise group increased their trunk flexion peak torque/body weight ratios by 18.1% while the control group decreased by 0.4%. Knee proprioception (combined right and left joint repositioning) improved 44.7% from pre- to post-training (p = 0.0006) and persisted (21.5%) for 9 months post-training. In addition there was a side interaction with the position sense of the right knee at 9 months showing 32.1% (p = 0.03) less deviation from the reference angle than the right knee during pre-testing. An instability-training program using Swiss balls with body weight as resistance can provide prolonged improvements in joint proprioception and core strength in previously untrained individuals performing this novel training stress which would contribute to general health. Key pointsAlthough traditional free weight resistance exercises have been recommended as most beneficial for improving strength and power in athletes (Behm et al., 2010b), an IT program using Swiss balls and body

  17. Striatal and thalamic GABA level concentrations play differential roles for the modulation of response selection processes by proprioceptive information.

    PubMed

    Dharmadhikari, Shalmali; Ma, Ruoyun; Yeh, Chien-Lin; Stock, Ann-Kathrin; Snyder, Sandy; Zauber, S Elizabeth; Dydak, Ulrike; Beste, Christian

    2015-10-15

    The selection of appropriate responses is a complex endeavor requiring the integration of many different sources of information in fronto-striatal-thalamic circuits. An often neglected but relevant piece of information is provided by proprioceptive inputs about the current position of our limbs. This study examines the importance of striatal and thalamic GABA levels in these processes using GABA-edited magnetic resonance spectroscopy (GABA-MRS) and a Simon task featuring proprioception-induced interference in healthy subjects. As a possible model of deficits in the processing of proprioceptive information, we also included Parkinson's disease (PD) patients in this study. The results show that proprioceptive information about unusual postures complicates response selection processes in controls, but not in PD patients. The well-known deficits of PD patients in processing proprioceptive information can turn into a benefit when altered proprioceptive information would normally complicate response selection processes. Striatal and thalamic GABA levels play dissociable roles in the modulation of response selection processes by proprioceptive information: Striatal GABA levels seem to be important for the general speed of responding, most likely because striatal GABA promotes response selection. In contrast, the modulation of response conflict by proprioceptive information is closely related to thalamic GABA concentrations with higher concentration being related to a smaller response conflict effect. The most likely explanation for this finding is that the thalamus is involved in the integration of sensorimotor, attentional, and cognitive information for the purpose of response formation. Yet, this effect in the thalamus vanishes when controls and PD patients were analyzed separately.

  18. Striatal and thalamic GABA level concentrations play differential roles for the modulation of response selection processes by proprioceptive information.

    PubMed

    Dharmadhikari, Shalmali; Ma, Ruoyun; Yeh, Chien-Lin; Stock, Ann-Kathrin; Snyder, Sandy; Zauber, S Elizabeth; Dydak, Ulrike; Beste, Christian

    2015-10-15

    The selection of appropriate responses is a complex endeavor requiring the integration of many different sources of information in fronto-striatal-thalamic circuits. An often neglected but relevant piece of information is provided by proprioceptive inputs about the current position of our limbs. This study examines the importance of striatal and thalamic GABA levels in these processes using GABA-edited magnetic resonance spectroscopy (GABA-MRS) and a Simon task featuring proprioception-induced interference in healthy subjects. As a possible model of deficits in the processing of proprioceptive information, we also included Parkinson's disease (PD) patients in this study. The results show that proprioceptive information about unusual postures complicates response selection processes in controls, but not in PD patients. The well-known deficits of PD patients in processing proprioceptive information can turn into a benefit when altered proprioceptive information would normally complicate response selection processes. Striatal and thalamic GABA levels play dissociable roles in the modulation of response selection processes by proprioceptive information: Striatal GABA levels seem to be important for the general speed of responding, most likely because striatal GABA promotes response selection. In contrast, the modulation of response conflict by proprioceptive information is closely related to thalamic GABA concentrations with higher concentration being related to a smaller response conflict effect. The most likely explanation for this finding is that the thalamus is involved in the integration of sensorimotor, attentional, and cognitive information for the purpose of response formation. Yet, this effect in the thalamus vanishes when controls and PD patients were analyzed separately. PMID:26142275

  19. Knee-Joint Proprioception During 30-Day 6 deg Head-Down Bed Rest with Isotonic and Isokinetic Exercise Training

    NASA Technical Reports Server (NTRS)

    Bernauer, E. M.; Walby, W. F.; Ertl, A. C.; Dempster, P. T.; Bond, M.; Greenleaf, J. E.

    1994-01-01

    To determine if daily isotonic exercise or isokinetic exercise training coupled with daily log proprioceptive training, would influence log proprioceptive tracking responses during Bed Rest (BR), 19 men (36 +/- SD 4 years, 178 +/- 7 cm, 76.8 +/- 7.8 kg) were allocated into a NO-Exercise (NOE) training control group (n = 5), and IsoTanic Exercise (ITE, n = 7) and IsoKinetic Exercise (IKE, n = 7) training groups. Exercise training was conducted during BR for two 30-min period / d, 5 d /week. Only the IKE group performed proprioceptive training using a now isokinetic procedure with each lower extremity for 2.5 min before and after the daily exercise training sessions; proprioceptive testing occurred weekly for all groups. There were no significant differences in proprioceptive tracking scores, expressed as a percentage of the perfect score of 100, in the pro-BR ambulatory control period between the three groups. Knee extension and flexion tracking responses were unchanged with NOE during BR, but were significantly greater (*p less than 0.05) at the end of BR in both exercise groups when compared with NOE responses (extension: NOE 80.7 +/- 0.7%, ITE 82.9 +/- 0.6%, IKE 86.5* +/- 0.7%; flexion: NOE 77.6 +/- 1.50, ITE 80.0 +/- 0.8% (NS), IKE 83.6* +/- 0.8%). Although proprioceptive tracking was unchanged during BR with NOE, both lsotonic exercise training (without additional propriaceptive training) and especially isokinetic exercise training when combined with daily proprioceptive training, significantly improved knee proprioceptive tracking responses after 30 d of BR.

  20. Relationship between paraspinal muscle cross-sectional area and relative proprioceptive weighting ratio of older persons with lumbar spondylosis.

    PubMed

    Ito, Tadashi; Sakai, Yoshihito; Nakamura, Eishi; Yamazaki, Kazunori; Yamada, Ayaka; Sato, Noritaka; Morita, Yoshifumi

    2015-07-01

    [Purpose] The purpose of this study was to examine the relationship between the paraspinal muscle cross-sectional area and the relative proprioceptive weighting ratio during local vibratory stimulation of older persons with lumbar spondylosis in an upright position. [Subjects] In all, 74 older persons hospitalized for lumbar spondylosis were included. [Methods] We measured the relative proprioceptive weighting ratio of postural sway using a Wii board while vibratory stimulations of 30, 60, or 240 Hz were applied to the subjects' paraspinal or gastrocnemius muscles. Back strength, abdominal muscle strength, and erector spinae muscle (L1/L2, L4/L5) and lumbar multifidus (L1/L2, L4/L5) cross-sectional areas were evaluated. [Results] The erector spinae muscle (L1/L2) cross-sectional area was associated with the relative proprioceptive weighting ratio during 60Hz stimulation. [Conclusion] These findings show that the relative proprioceptive weighting ratio compared to the erector spinae muscle (L1/L2) cross-sectional area under 60Hz proprioceptive stimulation might be a good indicator of trunk proprioceptive sensitivity.

  1. Slow Transit Constipation.

    PubMed

    Wald, Arnold

    2002-08-01

    The diagnosis of slow transit functional constipation is based upon diagnostic testing of patients with idiopathic constipation who responded poorly to conservative measures such as fiber supplements, fluids, and stimulant laxatives. These tests include barium enema or colonoscopy, colonic transit of radio-opaque markers, anorectal manometry, and expulsion of a water-filled balloon. Plain abdominal films can identify megacolon, which can be further characterized by barium or gastrografin studies. Colonic transit of radio-opaque markers identifies patients with slow transit with stasis of markers in the proximal colon. However, anorectal function should be characterized to exclude outlet dysfunction, which may coexist with colonic inertia. Because slow colonic transit is defined by studies during which patients consume a high-fiber diet, fiber supplements are generally not effective, nor are osmotic laxatives that consist of unabsorbed sugars. Stimulant laxatives are considered first-line therapy, although studies often show a diminished colonic motor response to such agents. There is no evidence to suggest that chronic use of such laxatives is harmful if they are used two to three times per week. Polyethylene glycol with or without electrolytes may be useful in a minority of patients, often combined with misoprostol. I prefer to start with misoprostol 200 mg every other morning and increase to tolerance or efficacy. I see no advantage in prescribing misoprostol on a TID or QID basis or even daily because it increases cramping unnecessarily. This drug is not acceptable in young women who wish to become pregnant. An alternative may be colchicine, which is reported to be effective when given as 0.6 mg TID. Long-term efficacy has not been studied. Finally, biofeedback is a risk-free approach that has been reported as effective in approximately 60% of patients with slow transit constipation in the absence of outlet dysfunction. Although difficult to understand

  2. Knee joint proprioception in normal volunteers and patients with anterior cruciate ligament tears, taking special account of the effect of a knee bandage.

    PubMed

    Jerosch, J; Prymka, M

    1996-01-01

    Proprioception of the knee joint was tested in 30 healthy volunteers with clinically inconspicuous knee joints. To examine proprioception, an angle reproduction test was performed. We could not document any differences between the left and the right knee joint or between men and women. At the mid-range, proprioception was worse compared with the end range of motion. In addition, 25 patients with an isolated rupture of the anterior cruciate ligament were evaluated, 14 before and 11 after operative anterior cruciate ligament (ACL) reconstruction. Preoperatively, there was a significant deterioration of proprioception compared with the control group. We were able to show a positive influence of a knee bandage on the proprioception of the injured knee. Patients after ACL reconstruction showed no significantly better proprioception compared with the preoperative group.

  3. 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.

  4. A model of a flexible anguilliform swimmer driven by a central pattern generator with proprioceptive feedback

    NASA Astrophysics Data System (ADS)

    Hamlet, Christina; Tytell, Eric; Hoffman, Kathleen; Fauci, Lisa

    2015-11-01

    The swimming of a simple vertebrate, the lamprey, can shed light on how a flexible body can couple with a fluid environment to swim rapidly and efficiently. Animals use proprioceptive sensory information to sense how their bodies are bending, and then adjust the neural signals to their muscles to improve performance. We will present recent progress in the development of a computational model of a lamprey swimming in a Navier-Stokes fluid where a simple central pattern generator model, based on phase oscillators, is coupled to the evolving body dynamics of the swimmer through curvature and curvature derivative feedback. Such feedback can be positive (frequency decreasing), negative (frequency increasing), or mixed (positive to one side of the body and negative to the other, or vice versa). We will examine how the emergent swimming behavior and cost of transport depends upon these functional forms of proprioceptive feedback chosen in the model.

  5. Agency elicits body-ownership: proprioceptive drift toward a synchronously acting external proxy.

    PubMed

    Asai, Tomohisa

    2016-05-01

    Awareness of our own bodies (sense of body-ownership) and actions (sense of agency) is fundamental for self-consciousness. In the rubber hand illusion, watching a rubber hand being stroked synchronously as one's own unseen hand is also stroked causes the observer to attribute the rubber hand to their own body. The findings of the series of experiments reported here suggest that body-ownership, measured using proprioceptive drift, is elicited by the external acting proxy that drives the sense of agency. While participants clasped and unclasped their left hand for 60 s, they focused on video feedback on a monitor in front of them. Proprioceptive drift was observed only under the conditions, including synchronized conditions, where the sense of agency for the acting proxy occurred, suggesting an essential interaction between body-ownership and agency.

  6. Defensive activation during the rubber hand illusion: Ownership versus proprioceptive drift.

    PubMed

    Riemer, Martin; Bublatzky, Florian; Trojan, Jörg; Alpers, Georg W

    2015-07-01

    A strong link between body perception and emotional experience has been proposed. To examine the interaction between body perception and anticipatory anxiety, two well-established paradigms were combined: The rubber hand illusion (RHI) and the threat-of-shock paradigm. An artificial hand and the participants' own hand (hidden from sight) were touched synchronously or asynchronously, while either threat-of-shock or safety was cued. Potentiated startle reflexes and enhanced skin conductance responses were observed during threat as compared to safety conditions, but threat conditions did not interact with illusory body perceptions. Thus, defense system activation was not modulated by altered body representations. Physiological responses increased with the sense of ownership for the artificial limb, but not with proprioceptive drift towards its location. The results indicate that ownership ratings and proprioceptive drift capture different aspects of the RHI. The study presents a new approach to investigate the relationship between body representations and emotional states.

  7. Effects of altered afferent articular input on sensation, proprioception, muscle tone and sympathetic reflex responses.

    PubMed

    Slosberg, M

    1988-10-01

    The influence of afferent articular and periarticular input on muscle tone, joint mobility, proprioception and pain is of considerable interest to practitioners using manipulation. It has long been hypothesized that dysfunctional articulations may generate altered patterns of afferent input. This article reviews the relevant studies that have investigated the impact of articular input on efferent activity under normal conditions and under conditions of altered joint function. The findings suggest that sensory input does have a substantial effect on efferent function and sensation. Furthermore, the studies indicate that the pattern of articular input may be significantly modified by joint inflammation, trauma and effusion and result in changes of muscle tone, joint mobility, proprioception and pain. PMID:3069947

  8. Sarcomeres Pattern Proprioceptive Sensory Dendritic Endings through UNC-52/Perlecan in C. elegans.

    PubMed

    Liang, Xing; Dong, Xintong; Moerman, Donald G; Shen, Kang; Wang, Xiangming

    2015-05-26

    Sensory dendrites innervate peripheral tissues through cell-cell interactions that are poorly understood. The proprioceptive neuron PVD in C. elegans extends regular terminal dendritic branches between muscle and hypodermis. We found that the PVD branch pattern was instructed by adhesion molecule SAX-7/L1CAM, which formed regularly spaced stripes on the hypodermal cell. The regularity of the SAX-7 pattern originated from the repeated and regularly spaced dense body of the sarcomeres in the muscle. The extracellular proteoglycan UNC-52/Perlecan linked the dense body to the hemidesmosome on the hypodermal cells, which in turn instructed the SAX-7 stripes and PVD dendrites. Both UNC-52 and hemidesmosome components exhibited highly regular stripes that interdigitated with the SAX-7 stripe and PVD dendrites, reflecting the striking precision of subcellular patterning between muscle, hypodermis, and dendrites. Hence, the muscular contractile apparatus provides the instructive cues to pattern proprioceptive dendrites. PMID:25982673

  9. Believing what you feel: using proprioceptive feedback to reduce unilateral neglect.

    PubMed

    Robertson, I H; Nico, D; Hood, B M

    1997-01-01

    Unilateral spatial neglect declines when participants reach to grip the center of long metal rods compared with when they point to the perceived center, suggesting that visuomotor control systems are less affected by neglect than other representational systems (I. H. Robertson, D. Nico, & B. Hood, 1995). In this study, 16 participants with unilateral left neglect actually picked up rods, and we predicted short-term improvements in neglect because of induced conflict between a phenomenally symmetrical visual world on the one hand and a proprioceptively conveyed rightward-biased world on the other. With participants serving as their own controls, significant short-term improvements in neglect were found on 2 out of 4 neglect tasks after participants experienced proprioceptive feedback discrepant from the judgments they made on the basis of visual information alone.

  10. Defensive activation during the rubber hand illusion: Ownership versus proprioceptive drift.

    PubMed

    Riemer, Martin; Bublatzky, Florian; Trojan, Jörg; Alpers, Georg W

    2015-07-01

    A strong link between body perception and emotional experience has been proposed. To examine the interaction between body perception and anticipatory anxiety, two well-established paradigms were combined: The rubber hand illusion (RHI) and the threat-of-shock paradigm. An artificial hand and the participants' own hand (hidden from sight) were touched synchronously or asynchronously, while either threat-of-shock or safety was cued. Potentiated startle reflexes and enhanced skin conductance responses were observed during threat as compared to safety conditions, but threat conditions did not interact with illusory body perceptions. Thus, defense system activation was not modulated by altered body representations. Physiological responses increased with the sense of ownership for the artificial limb, but not with proprioceptive drift towards its location. The results indicate that ownership ratings and proprioceptive drift capture different aspects of the RHI. The study presents a new approach to investigate the relationship between body representations and emotional states. PMID:25960069

  11. Effects of Massage on Muscular Strength and Proprioception After Exercise-Induced Muscle Damage.

    PubMed

    Shin, Mal-Soon; Sung, Yun-Hee

    2015-08-01

    Exercise-induced muscle damage (EIMD), which is commonly associated with eccentric exercise, unaccustomed exercise, and resistance training, may lead to delayed onset muscle soreness, swelling, decreased muscle strength, and range of motion. Many researchers have evaluated various interventions to treat the signs and symptoms of EIMD. However, the effects of massage after EIMD are unclear. Here, we investigated the effect of massage on muscle strength and proprioception after EIMD. All subjects randomly were divided into an EIMD-treated control group (n = 10) and a massage-treated after EIMD experimental group (n = 11). Exercise-induced muscle damage was induced by repeated exercise. Massage treatment was provided by physiotherapist for 15 minutes. It consists of light stroking, milking, friction, and skin rolling. Lactate was evaluated by Lactate Pro analyzer in pre- and postexercise. Surface electromyography (muscle activity) and sonography (muscle thickness) were used to confirm the muscular characteristics. Proprioception was investigated by dual inclinometer. As a result, massage treatment on the gastrocnemius after EIMD increased activation of the medial gastrocnemius during contraction (p ≤ 0.05). In the lateral and medial gastrocnemius, the θs, which is the angle between muscle fibers and superficial aponeurosis, showed a significant change (p ≤ 0.05). However, there are no differences in the θd, which is the angle between muscle fibers and deep aponeurosis. We also found that proprioceptive acuity in the ankle joint was significantly greater in the massage-treated experimental group compared with that in the control group (p ≤ 0.05). These findings suggest that massage of the gastrocnemius after EIMD can improve muscle strength and proprioception by influencing the superficial layer of the gastrocnemius. PMID:25226328

  12. Impaired Varus-Valgus Proprioception and Neuromuscular Stabilization in Medial Knee Osteoarthritis

    PubMed Central

    Chang, Alison H.; Lee, Song Joo; Zhao, Heng; Ren, Yupeng; Zhang, Li-Qun

    2014-01-01

    Impaired proprioception and poor muscular stabilization in the frontal plane may lead to knee instability during functional activities, a common complaint in persons with knee osteoarthritis (KOA). Understanding these frontal plane neuromechanical properties in KOA will help elucidate the factors contributing to knee instability and aid in the development of targeted intervention strategies. The study objectives were to compare knee varus-valgus proprioception, isometric muscle strength, and active muscular contribution to stability between persons with medial KOA and healthy controls. We evaluated knee frontal plane neuromechanical parameters in 14 participants with medial KOA and 14 age- and gender-matched controls, using a joint driving device (JDD) with a customized motor and a 6-axis force sensor. Analysis of covariance with BMI as a covariate was used to test the differences in varus-valgus neuromechanical parameters between these two groups. The KOA group had impaired varus proprioception acuity (1.08 ± 0.59° vs. 0.69 ± 0.49°, p < 0.05), decreased normalized varus muscle strength (1.31 ± 0.75% vs. 1.79 ± 0.84% body weight, p < 0.05), a trend toward decreased valgus strength (1.29 ± 0.67% vs. 1.88 ± 0.99%, p = 0.054), and impaired ability to actively stabilize the knee in the frontal plane during external perturbation (4.67 ± 2.86 vs. 8.26 ± 5.95 Nm/degree, p < 0.05). The knee frontal plane sensorimotor control system is compromised in persons with medial KOA. Our findings suggest varus-valgus control deficits in both the afferent input (proprioceptive acuity) and muscular effectors (muscle strength and capacity to stabilize the joint). PMID:24321442

  13. Short-term effects of proprioceptive training with unstable platform on athletes' stabilometry.

    PubMed

    Romero-Franco, Natalia; Martínez-López, Emilio J; Lomas-Vega, Rafael; Hita-Contreras, Fidel; Osuna-Pérez, M Catalina; Martínez-Amat, Antonio

    2013-08-01

    The purpose of this study was to determine the short-term stabilometric effects of proprioceptive training in athletes by using a BOSU ball and a Swiss ball as unstable platforms. Thirty-seven athletes from a variety of disciplines were divided into a control group (n = 17) and an experimental group (n = 20). Both performed a warm-up, and in addition, the experimental group carried out a proprioceptive exercise session after the warm-up. Proprioceptive exercise session consisted of six 25-minute exercise sessions with the BOSU ball and the Swiss ball as unstable platforms. Bipedal stabilometry was assessed before the training session (M0), immediately after training (M1), 30 minutes later (M2), 1 hour after training (M3), 6 hours after training (M4), and 24 hours after training (M5). Analysis of variance (α = 0.05) revealed significant differences immediately after training (M1) in speed (p = 0.022) and length covered by the center of pressure (p = 0.021) in the experimental group. These differences were even more acute 6 hours later (M4; p = 0.021). In fact, the same group exhibited significant differences in mediolateral position after 30 minutes (M2; p = 0.001) compared with the baseline measure and the control group. Apart from these, no other significant differences were found. A proprioceptive exercise session using a BOSU ball and a Swiss ball as unstable platforms induced short-term negative effects on the stabilometry of athletes. Likewise, an immediate trend to improvement was apparent in the stabilometry of the control group after the warm-up.

  14. Abnormal spatial localization in patients with herpes zoster ophthalmicus. Evidence for the presence of proprioceptive information.

    PubMed

    Campos, E C; Chiesi, C; Bolzani, R

    1986-08-01

    Patients with herpes zoster of the ophthalmic branch of the trigeminal nerve and normal ocular motility were examined. They were asked to point to targets without the sight of their own hand. Significant errors were found on the affected side. Proprioceptive information of the extraocular muscles is assumed to travel in the trigeminal nerve, and these results thus suggest the existence of peripheral afferent signals influencing eye-hand coordination.

  15. Generalization patterns for reach adaptation and proprioceptive recalibration differ after visuomotor learning.

    PubMed

    Cressman, Erin K; Henriques, Denise Y P

    2015-07-01

    Visuomotor learning results in changes in both motor and sensory systems (Cressman EK, Henriques DY. J Neurophysiol 102: 3505-3518, 2009), such that reaches are adapted and sense of felt hand position recalibrated after reaching with altered visual feedback of the hand. Moreover, visuomotor learning has been shown to generalize such that reach adaptation achieved at a trained target location can influence reaches to novel target directions (Krakauer JW, Pine ZM, Ghilardi MF, Ghez C. J Neurosci 20: 8916-8924, 2000). We looked to determine whether proprioceptive recalibration also generalizes to novel locations. Moreover, we looked to establish the relationship between reach adaptation and changes in sense of felt hand position by determining whether proprioceptive recalibration generalizes to novel targets in a similar manner as reach adaptation. On training trials, subjects reached to a single target with aligned or misaligned cursor-hand feedback, in which the cursor was either rotated or scaled in extent relative to hand movement. After reach training, subjects reached to the training target and novel targets (including targets from a second start position) without visual feedback to assess generalization of reach adaptation. Subjects then performed a proprioceptive estimation task, in which they indicated the position of their hand relative to visual reference markers placed at similar locations as the trained and novel reach targets. Results indicated that shifts in hand position generalized across novel locations, independent of reach adaptation. Thus these distinct sensory and motor generalization patterns suggest that reach adaptation and proprioceptive recalibration arise from independent error signals and that changes in one system cannot guide adjustments in the other.

  16. Mixed body- and gaze-centered coding of proprioceptive reach targets after effector movement.

    PubMed

    Mueller, Stefanie; Fiehler, Katja

    2016-07-01

    Previous studies demonstrated that an effector movement intervening between encoding and reaching to a proprioceptive target determines the underlying reference frame: proprioceptive reach targets are represented in a gaze-independent reference frame if no movement occurs but are represented with respect to gaze after an effector movement (Mueller and Fiehler, 2014a). The present experiment explores whether an effector movement leads to a switch from a gaze-independent, body-centered reference frame to a gaze-dependent reference frame or whether a gaze-dependent reference frame is employed in addition to a gaze-independent, body-centered reference frame. Human participants were asked to reach in complete darkness to an unseen finger (proprioceptive target) of their left target hand indicated by a touch. They completed 2 conditions in which the target hand remained either stationary at the target location (stationary condition) or was actively moved to the target location, received a touch and was moved back before reaching to the target (moved condition). We dissociated the location of the movement vector relative to the body midline and to the gaze direction. Using correlation and regression analyses, we estimated the contribution of each reference frame based on horizontal reach errors in the stationary and moved conditions. Gaze-centered coding was only found in the moved condition, replicating our previous results. Body-centered coding dominated in the stationary condition while body- and gaze-centered coding contributed equally strong in the moved condition. Our results indicate a shift from body-centered to combined body- and gaze-centered coding due to an effector movement before reaching towards proprioceptive targets.

  17. Robot-Assisted Training of the Kinesthetic Sense: Enhancing Proprioception after Stroke

    PubMed Central

    De Santis, Dalia; Zenzeri, Jacopo; Casadio, Maura; Masia, Lorenzo; Riva, Assunta; Morasso, Pietro; Squeri, Valentina

    2015-01-01

    Proprioception has a crucial role in promoting or hindering motor learning. In particular, an intact position sense strongly correlates with the chances of recovery after stroke. A great majority of neurological patients present both motor dysfunctions and impairments in kinesthesia, but traditional robot and virtual reality training techniques focus either in recovering motor functions or in assessing proprioceptive deficits. An open challenge is to implement effective and reliable tests and training protocols for proprioception that go beyond the mere position sense evaluation and exploit the intrinsic bidirectionality of the kinesthetic sense, which refers to both sense of position and sense of movement. Modulated haptic interaction has a leading role in promoting sensorimotor integration, and it is a natural way to enhance volitional effort. Therefore, we designed a preliminary clinical study to test a new proprioception-based motor training technique for augmenting kinesthetic awareness via haptic feedback. The feedback was provided by a robotic manipulandum and the test involved seven chronic hemiparetic subjects over 3 weeks. The protocol included evaluation sessions that consisted of a psychometric estimate of the subject’s kinesthetic sensation, and training sessions, in which the subject executed planar reaching movements in the absence of vision and under a minimally assistive haptic guidance made by sequences of graded force pulses. The bidirectional haptic interaction between the subject and the robot was optimally adapted to each participant in order to achieve a uniform task difficulty over the workspace. All the subjects consistently improved in the perceptual scores as a consequence of training. Moreover, they could minimize the level of haptic guidance in time. Results suggest that the proposed method is effective in enhancing kinesthetic acuity, but the level of impairment may affect the ability of subjects to retain their improvement in time

  18. Effects of Massage on Muscular Strength and Proprioception After Exercise-Induced Muscle Damage.

    PubMed

    Shin, Mal-Soon; Sung, Yun-Hee

    2015-08-01

    Exercise-induced muscle damage (EIMD), which is commonly associated with eccentric exercise, unaccustomed exercise, and resistance training, may lead to delayed onset muscle soreness, swelling, decreased muscle strength, and range of motion. Many researchers have evaluated various interventions to treat the signs and symptoms of EIMD. However, the effects of massage after EIMD are unclear. Here, we investigated the effect of massage on muscle strength and proprioception after EIMD. All subjects randomly were divided into an EIMD-treated control group (n = 10) and a massage-treated after EIMD experimental group (n = 11). Exercise-induced muscle damage was induced by repeated exercise. Massage treatment was provided by physiotherapist for 15 minutes. It consists of light stroking, milking, friction, and skin rolling. Lactate was evaluated by Lactate Pro analyzer in pre- and postexercise. Surface electromyography (muscle activity) and sonography (muscle thickness) were used to confirm the muscular characteristics. Proprioception was investigated by dual inclinometer. As a result, massage treatment on the gastrocnemius after EIMD increased activation of the medial gastrocnemius during contraction (p ≤ 0.05). In the lateral and medial gastrocnemius, the θs, which is the angle between muscle fibers and superficial aponeurosis, showed a significant change (p ≤ 0.05). However, there are no differences in the θd, which is the angle between muscle fibers and deep aponeurosis. We also found that proprioceptive acuity in the ankle joint was significantly greater in the massage-treated experimental group compared with that in the control group (p ≤ 0.05). These findings suggest that massage of the gastrocnemius after EIMD can improve muscle strength and proprioception by influencing the superficial layer of the gastrocnemius.

  19. Robot-assisted training of the kinesthetic sense: enhancing proprioception after stroke.

    PubMed

    De Santis, Dalia; Zenzeri, Jacopo; Casadio, Maura; Masia, Lorenzo; Riva, Assunta; Morasso, Pietro; Squeri, Valentina

    2014-01-01

    Proprioception has a crucial role in promoting or hindering motor learning. In particular, an intact position sense strongly correlates with the chances of recovery after stroke. A great majority of neurological patients present both motor dysfunctions and impairments in kinesthesia, but traditional robot and virtual reality training techniques focus either in recovering motor functions or in assessing proprioceptive deficits. An open challenge is to implement effective and reliable tests and training protocols for proprioception that go beyond the mere position sense evaluation and exploit the intrinsic bidirectionality of the kinesthetic sense, which refers to both sense of position and sense of movement. Modulated haptic interaction has a leading role in promoting sensorimotor integration, and it is a natural way to enhance volitional effort. Therefore, we designed a preliminary clinical study to test a new proprioception-based motor training technique for augmenting kinesthetic awareness via haptic feedback. The feedback was provided by a robotic manipulandum and the test involved seven chronic hemiparetic subjects over 3 weeks. The protocol included evaluation sessions that consisted of a psychometric estimate of the subject's kinesthetic sensation, and training sessions, in which the subject executed planar reaching movements in the absence of vision and under a minimally assistive haptic guidance made by sequences of graded force pulses. The bidirectional haptic interaction between the subject and the robot was optimally adapted to each participant in order to achieve a uniform task difficulty over the workspace. All the subjects consistently improved in the perceptual scores as a consequence of training. Moreover, they could minimize the level of haptic guidance in time. Results suggest that the proposed method is effective in enhancing kinesthetic acuity, but the level of impairment may affect the ability of subjects to retain their improvement in time.

  20. Slow Scan Telemedicine

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Originally developed under contract for NASA by Ball Bros. Research Corporation for acquiring visual information from lunar and planetary spacecraft, system uses standard closed circuit camera connected to a device called a scan converter, which slows the stream of images to match an audio circuit, such as a telephone line. Transmitted to its destination, the image is reconverted by another scan converter and displayed on a monitor. In addition to assist scans, technique allows transmission of x-rays, nuclear scans, ultrasonic imagery, thermograms, electrocardiograms or live views of patient. Also allows conferencing and consultation among medical centers, general practitioners, specialists and disease control centers. Commercialized by Colorado Video, Inc., major employment is in business and industry for teleconferencing, cable TV news, transmission of scientific/engineering data, security, information retrieval, insurance claim adjustment, instructional programs, and remote viewing of advertising layouts, real estate, construction sites or products.

  1. Slow change deafness.

    PubMed

    Neuhoff, John G; Wayand, Joseph; Ndiaye, Mamoudou C; Berkow, Ann B; Bertacchi, Breanna R; Benton, Catherine A

    2015-05-01

    In four experiments, we demonstrated a new phenomenon called "slow-change deafness." In Experiment 1 we presented listeners with continuous speech that changed three semitones in pitch over time, and we found that nearly 50 % failed to notice the change. Experiments 2 and 3 replicated the finding, demonstrated that the changes in the stimuli were well above threshold, and showed that when listeners were alerted to the possibility of a change, detection rates improved dramatically. Experiment 4 showed that increasing the magnitude of the change that occurred in the stimulus decreased the rate of change deafness. Our results are consistent with previous work that had shown that cueing listeners to potential auditory changes can significantly reduce change deafness. These findings support an account of change deafness that is dependent on both the magnitude of a stimulus change and listener expectations.

  2. Single Stance Stability and Proprioceptive Control in Older Adults Living at Home: Gender and Age Differences

    PubMed Central

    Riva, Dario; Mamo, Carlo; Fanì, Mara; Saccavino, Patrizia; Rocca, Flavio; Momenté, Manuel; Fratta, Marianna

    2013-01-01

    In developed countries, falls in older people represent a rising problem. As effective prevention should start before the risk becomes evident, an early predictor is needed. Single stance instability would appear as a major risk factor. Aims of the study were to describe single stance stability, its sensory components, and their correlation with age and gender. A random sample of 597 older adults (319 men, 278 women) living at home, aged 65–84, was studied. Stability tests were performed with an electronic postural station. The single stance test showed the impairment of single stance stability in older individuals (75–84 yrs). The significant decline of stability in the older subjects may be explained by the impairment of proprioceptive control together with the decrease in compensatory visual stabilization and emergency responses. Younger subjects (65–74 yrs) exhibited better, but still inadequate, proprioceptive control with compensatory visual stabilization. Gender differences appeared in older subjects: women were significantly less stable than men. The measurement of the sensory components of single stance stability could aid in the early detection of a decay in antigravity movements many years before the risk of falling becomes evident. Adequate proprioceptive control could mitigate the effects of all other risks of falling. PMID:23984068

  3. Importance of Proprioceptive Information for Postural Control in Children with Strabismus before and after Strabismus Surgery.

    PubMed

    Bucci, Maria P; Soufi, Hayette; Villeneuve, Philippe; Colleville, Lucile; Bui-Quoc, Emmanuel; Lions, Cynthia

    2016-01-01

    The objective of this study is to examine the role of proprioception in postural balance in children with strabismus before and after realignment of their visual axes by eye surgery. Postural recordings were made with the TechnoConcept® force platform in 23 children. Several conditions were studied, whether the subjects had both eyes open, or either the dominant or the non-dominant eye open, without and with foam pads of 4 mm underfoot. Recordings were performed before and after strabismus surgery. The surface area, the length and the mean speed of the center of pressure (CoP) were analyzed. Before strabismus surgery, all children showed better stability with both eyes open with respect to the condition with the non-dominant eye open; furthermore postural stability improved in the presence of foam pads. After surgery, the surface area of CoP decreased significantly, especially in the non-dominant eye viewing condition. We suggest that strabismic children use mainly proprioceptive information in order to control their posture, but also visual inputs, which are important for obtaining a good postural stability. The alignment of the visual axes after surgery provides enhanced postural stability, suggesting, again the major role of visual inputs in the control of posture. Proprioceptive plasticity after strabismus surgery may allow better visual rehabilitation. PMID:27656133

  4. Effects of proprioceptive training program on core stability and center of gravity control in sprinters.

    PubMed

    Romero-Franco, Natalia; Martínez-López, Emilio; Lomas-Vega, Rafael; Hita-Contreras, Fidel; Martínez-Amat, Antonio

    2012-08-01

    The purpose of this study was to determinate the effect of a 6-week specific-sprinter proprioceptive training program on core stability and gravity center control in sprinters. Thirty-three athletes (age = 21.82 ± 4.84 years, height = 1.76 ± 0.07 m, weight = 67.82 ± 08.04 kg, body mass index = 21.89 ± 2.37 kg · m(-2)) from sprint disciplines were divided into a control (n = 17) and experimental (n = 16) groups. A 30-minute proprioceptive training program was included in the experimental group training sessions, and it was performed for 6 weeks, 3 times each week. This program included 5 exercises with the BOSU and Swiss ball as unstable training tools that were designed to reproduce different moments of the technique of a sprint race. Stability with eyes open (EO) and eyes closed, postural stability, and gravity center control were assessed before and after the training program. Analyses of covariance (α = 0.05) revealed significant differences in stability in the medial-lateral plane with EO, gravity center control in the right direction and gravity center control in the back direction after the exercise intervention in the experimental athletes. Nevertheless, no other significant differences were demonstrated. A sprinter-specific proprioceptive training program provided postural stability with EO and gravity center control measures improvements, although it is not clear if the effect of training would transfer to the general population.

  5. Visual and proprioceptive contributions to postural control of upright stance in unilateral vestibulopathy.

    PubMed

    Eysel-Gosepath, Katrin; McCrum, Christopher; Epro, Gaspar; Brüggemann, Gert-Peter; Karamanidis, Kiros

    2016-06-01

    Preserving upright stance requires central integration of the sensory systems and appropriate motor output from the neuromuscular system to keep the centre of pressure (COP) within the base of support. Unilateral peripheral vestibular disorder (UPVD) causes diminished stance stability. The aim of this study was to determine the limits of stability and to examine the contribution of multiple sensory systems to upright standing in UPVD patients and healthy subjects. We hypothesized that closure of the eyes and Achilles tendon vibration during upright stance will augment the postural sway in UPVD patients more than in healthy subjects. Seventeen UPVD patients and 17 healthy subjects performed six tasks on a force plate: forwards and backwards leaning, to determine limits of stability, and upright standing with and without Achilles tendon vibration, each with eyes open and closed (with blackout glasses). The COP displacement of the patients was significantly greater in the vibration tasks than the controls and came closer to the posterior base of support boundary than the controls in all tasks. Achilles tendon vibration led to a distinctly more backward sway in both subject groups. Five of the patients could not complete the eyes closed with vibration task. Due to the greater reduction in stance stability when the proprioceptive, compared with the visual, sensory system was disturbed, we suggest that proprioception may be more important for maintaining upright stance than vision. UPVD patients, in particular, showed more difficulty in controlling postural stability in the posterior direction with visual and proprioceptive sensory disturbance.

  6. The combined effects of action observation and passive proprioceptive training on adaptive motor learning.

    PubMed

    Lei, Yuming; Bao, Shancheng; Wang, Jinsung

    2016-09-01

    Sensorimotor adaptation can be induced by action observation, and also by passive training. Here, we investigated the effect of a protocol that combined action observation and passive training on visuomotor adaptation, by comparing it with the effect of action observation or passive training alone. Subjects were divided into five conditions during the training session: (1) action observation, in which the subjects watched a video of a model who adapted to a novel visuomotor rotation; (2) proprioceptive training, in which the subject's arm was moved passively to target locations that were associated with desired trajectories; (3) combined training, in which the subjects watched the video of a model during a half of the session and experienced passive movements during the other half; (4) active training, in which the subjects adapted actively to the rotation; and (5) a control condition, in which the subjects did not perform any task. Following that session, all subjects adapted to the same visuomotor rotation. Results showed that the subjects in the combined training condition adapted to the rotation significantly better than those in the observation or proprioceptive training condition, although their performance was not as good as that of those who adapted actively. These findings suggest that although a protocol that combines action observation and passive training consists of all the processes involved in active training (error detection and correction, effector-specific and proprioceptively based reaching movements), these processes in that protocol may work differently as compared to a protocol in which the same processes are engaged actively.

  7. Importance of Proprioceptive Information for Postural Control in Children with Strabismus before and after Strabismus Surgery

    PubMed Central

    Bucci, Maria P.; Soufi, Hayette; Villeneuve, Philippe; Colleville, Lucile; Bui-Quoc, Emmanuel; Lions, Cynthia

    2016-01-01

    The objective of this study is to examine the role of proprioception in postural balance in children with strabismus before and after realignment of their visual axes by eye surgery. Postural recordings were made with the TechnoConcept® force platform in 23 children. Several conditions were studied, whether the subjects had both eyes open, or either the dominant or the non-dominant eye open, without and with foam pads of 4 mm underfoot. Recordings were performed before and after strabismus surgery. The surface area, the length and the mean speed of the center of pressure (CoP) were analyzed. Before strabismus surgery, all children showed better stability with both eyes open with respect to the condition with the non-dominant eye open; furthermore postural stability improved in the presence of foam pads. After surgery, the surface area of CoP decreased significantly, especially in the non-dominant eye viewing condition. We suggest that strabismic children use mainly proprioceptive information in order to control their posture, but also visual inputs, which are important for obtaining a good postural stability. The alignment of the visual axes after surgery provides enhanced postural stability, suggesting, again the major role of visual inputs in the control of posture. Proprioceptive plasticity after strabismus surgery may allow better visual rehabilitation. PMID:27656133

  8. The influence of proprioceptive state on learning control of reach dynamics.

    PubMed

    Green, Andrea M; Labelle, Jean-Philippe

    2015-10-01

    The motor system shows a remarkable capacity to generalize learned behavior to new contexts while simultaneously permitting learning of multiple and sometimes conflicting skills. To examine the influence of proprioceptive state on this capacity, we compared the effectiveness of changes in workspace location and limb orientation (horizontal vs. parasagittal plane posture) in facilitating learning of opposing dynamic force-field perturbations. When opposing fields were encountered in similar workspace positions and limb orientations, subjects failed to learn the two tasks. In contrast, differences in initial limb proprioceptive state were sufficient for significant learning to take place. The extent of learning was similar when the two fields were encountered in different arm orientations in a similar workspace location as compared to when learning took place in spatially separated workspace locations, consistent with the generalization of learning mainly in intrinsic joint coordinates. In keeping with these observations, examination of how trial-to-trial adaptation generalized showed that generalization tended to be greater across similar limb postures. However, when the two fields were encountered in distinct spatial locations, the extent of generalization of adaptation to one field depended on the limb orientation in which the other field was encountered. These results suggest that three-dimensional proprioceptive limb state plays an important role in modulating generalization patterns so as to permit the best compromise between broad generalization and the simultaneous learning of conflicting skills.

  9. Isolating Visual and Proprioceptive Components of Motor Sequence Learning in ASD.

    PubMed

    Sharer, Elizabeth A; Mostofsky, Stewart H; Pascual-Leone, Alvaro; Oberman, Lindsay M

    2016-05-01

    In addition to defining impairments in social communication skills, individuals with autism spectrum disorder (ASD) also show impairments in more basic sensory and motor skills. Development of new skills involves integrating information from multiple sensory modalities. This input is then used to form internal models of action that can be accessed when both performing skilled movements, as well as understanding those actions performed by others. Learning skilled gestures is particularly reliant on integration of visual and proprioceptive input. We used a modified serial reaction time task (SRTT) to decompose proprioceptive and visual components and examine whether patterns of implicit motor skill learning differ in ASD participants as compared with healthy controls. While both groups learned the implicit motor sequence during training, healthy controls showed robust generalization whereas ASD participants demonstrated little generalization when visual input was constant. In contrast, no group differences in generalization were observed when proprioceptive input was constant, with both groups showing limited degrees of generalization. The findings suggest, when learning a motor sequence, individuals with ASD tend to rely less on visual feedback than do healthy controls. Visuomotor representations are considered to underlie imitative learning and action understanding and are thereby crucial to social skill and cognitive development. Thus, anomalous patterns of implicit motor learning, with a tendency to discount visual feedback, may be an important contributor in core social communication deficits that characterize ASD. Autism Res 2016, 9: 563-569. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

  10. Importance of Proprioceptive Information for Postural Control in Children with Strabismus before and after Strabismus Surgery

    PubMed Central

    Bucci, Maria P.; Soufi, Hayette; Villeneuve, Philippe; Colleville, Lucile; Bui-Quoc, Emmanuel; Lions, Cynthia

    2016-01-01

    The objective of this study is to examine the role of proprioception in postural balance in children with strabismus before and after realignment of their visual axes by eye surgery. Postural recordings were made with the TechnoConcept® force platform in 23 children. Several conditions were studied, whether the subjects had both eyes open, or either the dominant or the non-dominant eye open, without and with foam pads of 4 mm underfoot. Recordings were performed before and after strabismus surgery. The surface area, the length and the mean speed of the center of pressure (CoP) were analyzed. Before strabismus surgery, all children showed better stability with both eyes open with respect to the condition with the non-dominant eye open; furthermore postural stability improved in the presence of foam pads. After surgery, the surface area of CoP decreased significantly, especially in the non-dominant eye viewing condition. We suggest that strabismic children use mainly proprioceptive information in order to control their posture, but also visual inputs, which are important for obtaining a good postural stability. The alignment of the visual axes after surgery provides enhanced postural stability, suggesting, again the major role of visual inputs in the control of posture. Proprioceptive plasticity after strabismus surgery may allow better visual rehabilitation.

  11. Evaluation of knee joint proprioception and balance of young female volleyball players: a pilot study

    PubMed Central

    Şahin, Neşe; Bianco, Antonino; Patti, Antonino; Paoli, Antonio; Palma, Antonio; Ersöz, Gülfem

    2015-01-01

    [Purpose] The main purpose of our study was the evaluation of the effects of long-term volleyball practice on knee joint proprioception and balance of young female athletes. [Subjects and Methods] An observational case-control study was performed. The study enrolled 19 female volleyball players in the experimental group and 19 sedentary counterparts as controls. A Biodex balance system and dynamometer were used for the evaluations. The paired t-test was used to determine the significance of differences between the performance of athletes and controls. [Results] The knee proprioception analysis showed a significant difference at 60° joint position in active and passive tests. A similar trend, but without significance, was found for the 20° joint position. In the postural stability tests both groups showed similar results with no significant differences between them. [Conclusion] In conclusion, the results indicate a significant influence on joint proprioception is elicited by long-term exposure to a team sport like volleyball. However, the postural stability indexes showed similar trends in both groups, highlighting the analogous ontogenesis of the subjects investigated and the low influence of volleyball practice on postural stability. PMID:25729185

  12. Chronic physical activity preserves efficiency of proprioception in postural control in older women.

    PubMed

    Maitre, Julien; Jully, Jean-Louis; Gasnier, Yannick; Paillard, Thierry

    2013-01-01

    The purpose of this study was to compare the effects of proprioceptive disruption on postural control for participants of different ages according to their physical and/or sport activity levels. Two groups of young and old participants who practiced chronic physical and/or sport activities (young active [n = 17; average age 20.5 +/- 1.1 yr] and old active [n = 17; average age 74.0 +/- 3.8 yr]) and two groups of young and old participants who did not practice physical and/or sport activities (young sedentary [n = 17; average age 20.0 +/- 1.3 yr] and old sedentary [n = 17; average age 74.7 +/- 6.3 yr]) participated in the study. They were compared in a bipedal quiet stance reference condition and a bilateral Achilles tendon vibration condition. Center of foot pressure displacements and frequency analysis were compared between the groups. The results indicated that when proprioceptive information was disrupted, the postural control disturbance was more important for the old sedentary group than for the other groups. There were no differences between the old active group and the young sedentary group. Postural control was less altered for the young active group than for the other groups. Aging decreases the efficiency of postural control regardless of the assessment conditions. Physical and sport activities may compensate for the disturbing effects of proprioceptive perturbation through a better use of sensory information whatever the age of the participants.

  13. The Effect of Repetitive Passive and Active Movements on Proprioception Ability in Forearm Supination

    PubMed Central

    Kwon, OhSung; Lee, SeungWon; Lee, YoungWoo; Seo, DongKwon; Jung, SangWoo; Choi, WonJae

    2013-01-01

    [Purpose] This study was conducted in order to investigate the effect of repetitive passive movement and repetitive active movement on proprioception in forearm supination. [Subjects] This study had a cross-sectional design. Twenty-three right-handed healthy subjects were recruited. All subjects randomly received both repetitive passive movement and repetitive active movement (repetitive passive/active movement at 120°/s with 60 repetitions over a 0–80° range). Active and passive joint repositioning of all subjects was measured using the error score for position sense, both before and after repositioning intervention. [Results] In the repetitive passive movement test, there was a statistically significant decrease in the pre- versus post-repositioning error scores in the active and passive angle examinations. In the repetitive active movement test, there was a statistically significant increase in pre- versus post-repositioning error scores in the active and passive angle examinations. In the comparison of position sense, there was a statistically significant decrease in both active and passive angle repositioning error scores in repetitive passive movement versus repetitive active movement. [Conclusion] Repetitive passive movement improved the proprioception results for forearm supination, compared to repetitive active movement. Results of this study indicate that repetitive passive movement can be recommended to clinicians for rehabilitation therapy as it provides greater proprioception benefits. PMID:24259808

  14. Skill level, vision, and proprioception in simple one-hand catching.

    PubMed

    Fischman, M G; Schneider, T

    1985-06-01

    Two experiments examined the interaction of vision and articular proprioception in simple one-hand catching. In Experiment 1 (N = 18) skilled baseball and softball players used the left and right hands to catch slowly moving tennis balls, while Experiment 2 (N = 16) used novice catchers as subjects. In half the trials, sight of the catching hand was prevented by placing a screen alongside the subjects' face. Results of Experiment 1 revealed that the screen caused minimal disruption of the positioning phase of the catch, with moderate disruption of the grasping phase. However, for the unskilled subjects of Experiment 2, the screen caused considerable disruption of positioning. The data provide only minimal support for Smyth and Marriott' (1982) contention that limb position is inadequately specified by articular proprioception. It is argued that skill level serves as a mediator in the ability to use proprioception for limb positioning, but vision appears necessary to control the precise temporal organization of the grasp phase of one-hand catching.

  15. Thoracolumbar fascia does not influence proprioceptive signaling from lumbar paraspinal muscle spindles in the cat

    PubMed Central

    Cao, Dong-Yuan; Pickar, Joel G

    2009-01-01

    The thoracolumbar fascia attaches to the lumbar spinous processes and encloses the paraspinal muscles to form a muscle compartment. Because muscle spindles can respond to transverse forces applied at a muscle’s surface, we were interested in the mechanical effects this fascia may have on proprioceptive signaling from lumbar paraspinal muscles during vertebral movement. The discharge of paraspinal muscle spindles at rest and in response to muscle history were investigated in the presence and absence of the thoracolumbar fascia in anesthetized cats. Muscle-history was induced by positioning the L6 vertebra in conditioning directions that lengthened and shortened the paraspinal muscles. The vertebra was then returned to an intermediate position for testing the spindles. Neither resting discharge (P= 0.49) nor the effects of muscle history (P>0.30) was significantly different with the fascia intact vs. removed. Our data showed that the thoracolumbar fascia did not influence proprioceptive signaling from lumbar paraspinal muscles spindles during small passive vertebral movements in cats. In addition, comparison of the transverse threshold pressures needed to stimulate our sample of muscle spindles in the cat with the thoracolumbar fascia compartmental pressures measured in humans during previous studies suggests that the thoracolumbar fascia likely does not affect proprioceptive signaling from lumbar paraspinal muscle spindles in humans. PMID:19627391

  16. Isolating Visual and Proprioceptive Components of Motor Sequence Learning in ASD.

    PubMed

    Sharer, Elizabeth A; Mostofsky, Stewart H; Pascual-Leone, Alvaro; Oberman, Lindsay M

    2016-05-01

    In addition to defining impairments in social communication skills, individuals with autism spectrum disorder (ASD) also show impairments in more basic sensory and motor skills. Development of new skills involves integrating information from multiple sensory modalities. This input is then used to form internal models of action that can be accessed when both performing skilled movements, as well as understanding those actions performed by others. Learning skilled gestures is particularly reliant on integration of visual and proprioceptive input. We used a modified serial reaction time task (SRTT) to decompose proprioceptive and visual components and examine whether patterns of implicit motor skill learning differ in ASD participants as compared with healthy controls. While both groups learned the implicit motor sequence during training, healthy controls showed robust generalization whereas ASD participants demonstrated little generalization when visual input was constant. In contrast, no group differences in generalization were observed when proprioceptive input was constant, with both groups showing limited degrees of generalization. The findings suggest, when learning a motor sequence, individuals with ASD tend to rely less on visual feedback than do healthy controls. Visuomotor representations are considered to underlie imitative learning and action understanding and are thereby crucial to social skill and cognitive development. Thus, anomalous patterns of implicit motor learning, with a tendency to discount visual feedback, may be an important contributor in core social communication deficits that characterize ASD. Autism Res 2016, 9: 563-569. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. PMID:26442448

  17. Bimanual proprioceptive performance differs for right- and left-handed individuals.

    PubMed

    Han, Jia; Waddington, Gordon; Adams, Roger; Anson, Judith

    2013-05-10

    It has been proposed that asymmetry between the upper limbs in the utilization of proprioceptive feedback arises from functional differences in the roles of the preferred and non-preferred hands during bimanual tasks. The present study investigated unimanual and bimanual proprioceptive performance in right- and left-handed young adults with an active finger pinch movement discrimination task. With visual information removed, participants were required to make absolute judgments about the extent of pinch movements made to physical stops, either by one hand, or by both hands concurrently, with the sequence of presented movement extents varied randomly. Discrimination accuracy scores were derived from participants' responses using non-parametric signal detection analysis. Consistent with previous findings, a non-dominant hand/hemisphere superiority effect was observed, where the non-dominant hands of right- and left-handed individuals performed overall significantly better than their dominant hands. For all participants, bimanual movement discrimination scores were significantly lower than scores obtained in the unimanual task. However, the magnitude of the performance reduction, from the unimanual to the bimanual task, was significantly greater for left-handed individuals. The effect whereby bimanual proprioception was disproportionately affected in left-handed individuals could be due to enhanced neural communication between hemispheres in left-handed individuals leading to less distinctive separation of information obtained from the two hands in the cerebral cortex.

  18. Hip proprioceptive feedback influences the control of mediolateral stability during human walking

    PubMed Central

    Roden-Reynolds, Devin C.; Walker, Megan H.; Wasserman, Camille R.

    2015-01-01

    Active control of the mediolateral location of the feet is an important component of a stable bipedal walking pattern, although the roles of sensory feedback in this process are unclear. In the present experiments, we tested whether hip abductor proprioception influenced the control of mediolateral gait motion. Participants performed a series of quiet standing and treadmill walking trials. In some trials, 80-Hz vibration was applied intermittently over the right gluteus medius (GM) to evoke artificial proprioceptive feedback. During walking, the GM was vibrated during either right leg stance (to elicit a perception that the pelvis was closer mediolaterally to the stance foot) or swing (to elicit a perception that the swing leg was more adducted). Vibration during quiet standing evoked leftward sway in most participants (13 of 16), as expected from its predicted perceptual effects. Across the 13 participants sensitive to vibration, stance phase vibration caused the contralateral leg to be placed significantly closer to the midline (by ∼2 mm) at the end of the ongoing step. In contrast, swing phase vibration caused the vibrated leg to be placed significantly farther mediolaterally from the midline (by ∼2 mm), whereas the pelvis was held closer to the stance foot (by ∼1 mm). The estimated mediolateral margin of stability was thus decreased by stance phase vibration but increased by swing phase vibration. Although the observed effects of vibration were small, they were consistent with humans monitoring hip proprioceptive feedback while walking to maintain stable mediolateral gait motion. PMID:26289467

  19. Proprioceptive ability at the lips and jaw measured using the same psychophysical discrimination task.

    PubMed

    Frayne, Ellie; Coulson, Susan; Adams, Roger; Croxson, Glen; Waddington, Gordon

    2016-06-01

    In the human face, the muscles and joints that generate movement have different properties. Whereas the jaw is a conventional condyle joint, the facial musculature has neither distinct origin nor insertion points, and the muscles do not contain muscle spindle proprioceptors. This current study aims to compare the proprioceptive ability at the orofacial muscles with that of the temporomandibular joint (TMJ) in 21 neuro-typical people aged between 18 and 65 years. A novel psychophysical task was devised for use with both structures that involved a fixed 30.5 mm start separation followed by closure onto stimuli of 5, 6, 7, 8 mm diameter. The mean proprioceptive score when using the lips was 0.84 compared to 0.79 at the jaw (p < 0.001), and response error was lower by 0.1 mm. The greater accuracy in discrimination of lip movement is significant because, unlike the muscles controlling the TMJ, the orbicularis oris muscle controlling the lips inserts on to connective tissue and other muscle, and contains no muscle spindles, implying a different more effective, proprioceptive mechanism. Additionally, unlike the lack of correlation previously observed between joints in the upper and lower limbs, at the face the scores from performing the task with the two different structures were significantly correlated (r = 0.5, p = 0.018). These data extend the understanding of proprioception being correlated for the same left and right joints and correlated within the same structure (e.g. ankle dorsiflexion and inversion), to include use-dependant proprioception, with performance in different structures being correlated through extended coordinated use. At the lips and jaw, it is likely that this arises from extensive coordinated use. This informs clinical assessment and suggests a potential for coordinated post-injury training of the lips and jaw, as well as having the potential to predict premorbid function via measurement of the uninjured structure, when monitoring

  20. Proprioceptive ability at the lips and jaw measured using the same psychophysical discrimination task.

    PubMed

    Frayne, Ellie; Coulson, Susan; Adams, Roger; Croxson, Glen; Waddington, Gordon

    2016-06-01

    In the human face, the muscles and joints that generate movement have different properties. Whereas the jaw is a conventional condyle joint, the facial musculature has neither distinct origin nor insertion points, and the muscles do not contain muscle spindle proprioceptors. This current study aims to compare the proprioceptive ability at the orofacial muscles with that of the temporomandibular joint (TMJ) in 21 neuro-typical people aged between 18 and 65 years. A novel psychophysical task was devised for use with both structures that involved a fixed 30.5 mm start separation followed by closure onto stimuli of 5, 6, 7, 8 mm diameter. The mean proprioceptive score when using the lips was 0.84 compared to 0.79 at the jaw (p < 0.001), and response error was lower by 0.1 mm. The greater accuracy in discrimination of lip movement is significant because, unlike the muscles controlling the TMJ, the orbicularis oris muscle controlling the lips inserts on to connective tissue and other muscle, and contains no muscle spindles, implying a different more effective, proprioceptive mechanism. Additionally, unlike the lack of correlation previously observed between joints in the upper and lower limbs, at the face the scores from performing the task with the two different structures were significantly correlated (r = 0.5, p = 0.018). These data extend the understanding of proprioception being correlated for the same left and right joints and correlated within the same structure (e.g. ankle dorsiflexion and inversion), to include use-dependant proprioception, with performance in different structures being correlated through extended coordinated use. At the lips and jaw, it is likely that this arises from extensive coordinated use. This informs clinical assessment and suggests a potential for coordinated post-injury training of the lips and jaw, as well as having the potential to predict premorbid function via measurement of the uninjured structure, when monitoring

  1. Slow frictional waves

    NASA Astrophysics Data System (ADS)

    Viswanathan, Koushik; Sundaram, Narayan; Chandrasekar, Srinivasan

    Stick-slip, manifest as intermittent tangential motion between two dry solid surfaces, is a friction instability that governs diverse phenomena from automobile brake squeals to earthquakes. We show, using high-speed in situ imaging of an adhesive polymer interface, that low velocity stick-slip is fundamentally of three kinds, corresponding to passage of three different surface waves -- separation pulses, slip pulses and the well-known Schallamach waves. These waves, traveling much slower than elastic waves, have clear distinguishing properties. Separation pulses and Schallamach waves involve local interface separation, and propagate in opposite directions while slip pulses are characterized by a sharp stress front and do not display any interface detachment. A change in the stick-slip mode from separation to slip pulse is effected simply by increasing the normal force. Together, these three waves constitute all possible stick-slip modes in adhesive friction and are shown to have direct analogues in muscular locomotory waves in soft bodied invertebrates. A theory for slow wave propagation is also presented which is capable of explaining the attendant interface displacements, velocities and stresses.

  2. Slow launch for HGH.

    PubMed

    Gilden, D

    1995-05-01

    The human growth hormone (HGH) expanded access program for people with AIDS wasting syndrome is now in its fourth month. Enrollment has been slow, largely due to cost. Since HGH falls under the Food and Drug Administration's (FDA) Treatment Investigational New Drug (TIND) regulations, patients are required to pay for the drug--at a cost of about $150 per day, or more than $1,000 per week. Few insurance companies will compensate for the cost of HGH, and no state Medicaid or AIDS Drug Assistance Programs have agreed to cover the compound. Serono Laboratories, the manufacturer, is operating an indigent program that provides free or discount HGH for individuals who cannot purchase the drug any other way. There are only 25 slots available in this program. Lack of available data on how and when to use the drug creates obstacles for physicians. Most of the public data available comes from a single, twelve-week, placebo-controlled study involving 178 participants. However, there are alternative treatments for wasting syndrome. A regimen of testosterone and synthetic anabolic steroids, given to men, has provided positive results on an anecdotal basis. Wasting syndrome comes from a metabolic change which occurs with chronic HIV infection. Rather than first using stores of fat, the body breaks down protein to meet its energy requirements.

  3. Can ageing be slowed?

    PubMed Central

    Gaman, L; Stoian, I; Atanasiu, V

    2011-01-01

    Redox metabolism has long been considered to play important roles in aging and the development of age-related diseases. Both dietary and pharmacological manipulations of redox metabolism have been associated with the extension of lifespan. Increasing new evidence s also suggests that the process of aging may derive from imperfect clearance of oxidatively damaged material. The accumulation of this molecular “garbage”, relatively indigestible, further hinders cellular functions, induces progressive failure of maintenance and repair and increases the probability of death. One important trend in anti–aging strategy is, therefore, to prevent or even revert the accumulation of these oxidatively altered molecules by stimulating the maintenance and repair systems through hormesis. A promising approach for slowing down ageing and achieving a healthy senescence is represented by repeated exposure to various mild stresses (caloric restriction, moderate exercise, nutritional or pharmacological hormetins). This article reviews the potential therapeutic tools available to date for increasing longevity and obtaining and successful ageing from the redox and hormetic perspective. PMID:22514565

  4. The Kinematic Control During the Backward Gait and Knee Proprioception: Insights from Lesions of the Anterior Cruciate Ligament

    PubMed Central

    Viggiano, Davide; Corona, Katia; Cerciello, Simone; Vasso, Michele; Schiavone-Panni, Alfredo

    2014-01-01

    An already existing large volume of work on kinematics documents a reduction of step length during unusual gaits, such as backward walking. This is mainly explained in terms of modifications of some biomechanical properties. In the present study, we propose that the proprioceptive information from the knee may be involved in this change of motor strategy. Specifically, we show that a non-automated condition such as backward walking can elicit different motor strategies in subjects with reduced proprioceptive feedback after anterior cruciate ligament lesion (ACL). For this purpose, the kinematic parameters during forward and backward walking in subjects with ACL deficit were compared to two control groups: a group with intact ACL and a group with surgically reconstructed ACL. The knee proprioception was tested measuring the threshold for detection of passive knee motion. Subjects were asked to walk on a level treadmill at five different velocities (1–5km/h) in forward and backward direction, thereby calculating the cadence and step length. Results showed that forward walking parameters were largely unaffected in subjects with ACL damage. However, they failed to reduce step length during backward walking, a correction that was normally observed in all control subjects and in subjects with normal proprioceptive feedback after ACL reconstruction. The main result of the present study is that knee proprioception is an important signal used by the brain to reduce step length during the backward gait. This can have a significant impact on clinical evaluation and rehabilitation. PMID:25114731

  5. Source modeling sleep slow waves

    PubMed Central

    Murphy, Michael; Riedner, Brady A.; Huber, Reto; Massimini, Marcello; Ferrarelli, Fabio; Tononi, Giulio

    2009-01-01

    Slow waves are the most prominent electroencephalographic (EEG) feature of sleep. These waves arise from the synchronization of slow oscillations in the membrane potentials of millions of neurons. Scalp-level studies have indicated that slow waves are not instantaneous events, but rather they travel across the brain. Previous studies of EEG slow waves were limited by the poor spatial resolution of EEGs and by the difficulty of relating scalp potentials to the activity of the underlying cortex. Here we use high-density EEG (hd-EEG) source modeling to show that individual spontaneous slow waves have distinct cortical origins, propagate uniquely across the cortex, and involve unique subsets of cortical structures. However, when the waves are examined en masse, we find that there are diffuse hot spots of slow wave origins centered on the lateral sulci. Furthermore, slow wave propagation along the anterior−posterior axis of the brain is largely mediated by a cingulate highway. As a group, slow waves are associated with large currents in the medial frontal gyrus, the middle frontal gyrus, the inferior frontal gyrus, the anterior cingulate, the precuneus, and the posterior cingulate. These areas overlap with the major connectional backbone of the cortex and with many parts of the default network. PMID:19164756

  6. Evaluation of the relative contribution of peripheral and focal vision to proprioceptive differentiation of underfoot inversion angles in young elite athletes.

    PubMed

    Witchalls, Jeremy; Waddington, Gordon; Adams, Roger; Blanch, Peter

    2013-12-01

    Different visual conditions during proprioceptive testing have the potential to mask clinically meaningful differences in proprioceptive acuity, and must be understood in order to improve testing accuracy. This study compared the proprioceptive acuity achieved in estimating underfoot surface angles when looking ahead vs looking down during an active stepping task. 40 athletes from national development squads (23 male, 17 female, M age = 16 yr.) judged the inversion angle of a footplate when stepping onto and across it. 19 participants were permitted to briefly look down and see the footplate before stepping onto it, while 21 looked ahead and saw the footplate only in peripheral vision as they walked across. Looking down before stepping contributed to higher proprioceptive acuity scores. These results indicate that during a stepping task, a short opportunity to assess ground angle with focal vision supports the peripheral sensory receptors in proprioceptive acuity to a greater extent than peripheral vision alone.

  7. [The influence of proprioceptive insoles (Bourdiol) on the sagittal curvature and inclination of the trunk].

    PubMed

    Müller-Gliemann, C; Drerup, B; Osada, N; Wetz, H H

    2006-11-01

    Proprioceptive insoles rely on the concept of Réné-Jaques Bourdiol, a French neurologist. The aim is to modulate plantar surface sensibility and to influence posture and statics of patients: it is hypothesized that the effect of modified afferent sensory input through proprioceptive stimulation of terminal muscle chains will have either a relaxing or stimulating effect on the whole body, which may be realized by affecting the posture. Small pads with a thickness of typically 1-3 mm are embedded into the insole to provide a specific stimulation. In fitting the insoles selectively to the individual patient the effect of the insoles on the trunk posture is taken as a feedback. This study investigates the influence of proprioceptive insoles on the sagittal curve in 20 selected patients. The protocol used a repeated measures research design. The measures of the sagittal curve were obtained using raster stereography. The four different conditions were: (1) barefoot, (2) convenient shoes without the insoles, (3) the same shoes with a placebo insole, and (4) the same shoes with neurological insoles. Evaluation of raster stereographs provided the kyphotic angle between T4 and T12 and lordotic angle between T12 and S1. Statistical evaluation was performed with the t-test for paired measurements. No significant differences were found in the sagittal profile. Only trunk inclination in normal posture was found to yield a significant difference (0.38 degrees) between placebo and neurological insoles. However, no clear statement on the efficiency of neurological insoles can be made.

  8. Correlation study of knee joint proprioception test results using common test methods

    PubMed Central

    Li, Lin; Ji, Zhong-Qiu; Li, Yan-Xia; Liu, Wei-Tong

    2016-01-01

    [Purpose] To study the correlation of the results obtained from different proprioception test methods, namely, the joint angle reset method, the motion minimum threshold measurement method, and the force sense reproduction method, performed on the same subjects’ knees. [Subjects and Methods] Different proprioception test methods, the joint angle reset method, the motion minimum threshold measurement method and the force sense reproduction method were used to test the knees of 30 healthy young men. [Results] Correlations were found in the following descending order from strong to weak: the correlation between the joint angle reset method and the force sense reproduction method (correlation coefficient of 0.41), the correlation between the joint angle reset method and the motion minimum threshold measurement method (correlation coefficient of 0.29), the correlation between the motion minimum threshold measurement method and the force sense reproduce method (correlation coefficient of 0.15). [Conclusion] No correlation was found among the results obtained using the joint angle reset method, the motion minimum threshold measurement method and the force sense reproduction method. Therefore, no correlation was found among the position sense, the motion sense and the force sense represented by these methods. Using the results of only one of the test methods to represent proprioception is one-sided. Force sensation depends more on the sensory input of information from the Golgi tendon organs, motion sense depends more on the input information of the muscle spindles, and position sense relies on the double input information of the muscle spindles and the Golgi tendon organs. PMID:27065533

  9. Proprioceptive role for palisade endings in extraocular muscles: evidence from the Jendrassik Maneuver.

    PubMed

    Niechwiej-Szwedo, E; González, E; Bega, S; Verrier, M C; Wong, A M; Steinbach, M J

    2006-07-01

    A proprioceptive hypothesis for the control of eye movements has been recently proposed based on neuroanatomical tracing studies. It has been suggested that the non-twitch motoneurons could be involved in modulating the gain of sensory feedback from the eye muscles analogous to the gamma (gamma) motoneurons which control the gain of proprioceptive feedback in skeletal muscles. We conducted behavioral and psychophysical experiments to test the above hypothesis using the Jendrassik Maneuver (JM) to alter the activity of gamma motoneurons. It was hypothesized that the JM would alter the proprioceptive feedback from the eye muscles which would result in misregistration of eye position and mislocalization of targets. In the first experiment, vergence eye movements and pointing responses were examined. Data showed that the JM affected the localization responses but not the actual eye position. Perceptual judgments were tested in the second experiment, and the results showed that targets were perceived as farther when the afferent feedback was altered by the JM. Overall, the results from the two experiments showed that eye position was perceived as more divergent with the JM, but the actual eye movements were not affected. We tested this further in Experiment 3 by examining the effect of JM on the amplitude and velocity of saccadic eye movements. As expected, there were no significant differences in saccadic parameters between the control and experimental conditions. Overall, the present study provides novel insight into the mechanism which may be involved in the use of sensory feedback from the eye muscles. Data from the first two experiments support the hypothesis that the JM alters the registered eye position, as evidenced by the localization errors. We propose that the altered eye position signal is due to the effect of the JM which changes the gain of the sensory feedback from the eye muscles, possibly via the activity of non-twitch motoneurons.

  10. Processing of proprioceptive and vestibular body signals and self-transcendence in Ashtanga yoga practitioners

    PubMed Central

    Fiori, Francesca; David, Nicole; Aglioti, Salvatore M.

    2014-01-01

    In the rod and frame test (RFT), participants are asked to set a tilted visual linear marker (i.e., a rod), embedded in a square, to the subjective vertical, irrespective of the surrounding frame. People not influenced by the frame tilt are defined as field-independent, while people biased in their rod verticality perception are field-dependent. Performing RFT requires the integration of proprioceptive, vestibular and visual signals with the latter accounting for field-dependency. Studies indicate that motor experts in body-related, balance-improving disciplines tend to be field-independent, i.e., better at verticality perception, suggesting that proprioceptive and vestibular expertise acquired by such exercise may weaken the influence of irrelevant visual signals. What remains unknown is whether the effect of body-related expertise in weighting perceptual information might also be mediated by personality traits, in particular those indexing self-focusing abilities. To explore this issue, we tested field-dependency in a class of body experts, namely yoga practitioners and in non-expert participants. Moreover we explored any link between performance on RFT and self-transcendence (ST), a complex personality construct, which refers to tendency to experience spiritual feelings and ideas. As expected, yoga practitioners (i) were more accurate in assessing the rod's verticality on the RFT, and (ii) expressed significantly higher ST. Interestingly, the performance in these two tests was negatively correlated. More specifically, when asked to provide verticality judgments, highly self-transcendent yoga practitioners were significantly less influenced by a misleading visual context. Our results suggest that being highly self-transcendent may enable yoga practitioners to optimize verticality judgment tasks by relying more on internal (vestibular and proprioceptive) signals coming from their own body, rather than on exteroceptive, visual cues. PMID:25278866

  11. On the contributions of vision and proprioception to the representation of hand-near targets

    PubMed Central

    Marlin, Matthew C.; Morrow, Sarah

    2014-01-01

    Performance is often improved when targets are presented in space near the hands rather than far from the hands. Performance in hand-near space may be improved because participants can use proprioception from the nearby limb and hand to provide a narrower and more resolute frame of reference. An equally compelling alternative is that targets appearing near the hand fall within the receptive fields of visual-tactile bimodal cells, recruiting them to assist in the visual representation of targets that appear near but not far from the hand. We distinguished between these two alternatives by capitalizing on research showing that vision and proprioception have differential effects on the precision of target representation (van Beers RJ, Sittig AC, Denier van der Gon JJ. Exp Brain Res 122: 367–377, 1998). Participants performed an in-to-center reaching task to an array of central target locations with their right hand, while their left hand rested near (beneath) or far from the target array. Reaching end-point accuracy, variability, time, and speed were assessed. We predicted that if proprioception contributes to the representation of hand-near targets, then error variability in depth will be smaller in the hand-near condition than in the hand-far condition. By contrast, if vision contributes to the representation of hand-near targets, then error variability along the lateral dimension will be smaller in the hand-near than in the hand-far condition. Our results showed that the placement of the hand near the targets reduced end-point error variability along the lateral dimension only. The results suggest that hand-near targets are represented with greater visual resolution than far targets. PMID:25339706

  12. Ankle proprioceptive acuity is associated with objective as well as self-report measures of balance, mobility, and physical function.

    PubMed

    Deshpande, Nandini; Simonsick, Eleanor; Metter, E Jeffrey; Ko, Seunguk; Ferrucci, Luigi; Studenski, Stephanie

    2016-06-01

    Ankle proprioceptive information is integrated by the central nervous system to generate and modulate muscle contractions for maintaining standing balance. This study evaluated the association of ankle joint proprioception with objective and self-report measures of balance, mobility, and physical function across the adult life span. Seven hundred and ninety participants (age range 24-97 years, 362 women) who completed ankle proprioception assessment between 2010 and 2014 were included in the present study from the population-based cohort of the Baltimore Longitudinal Study of Aging (BLSA), USA. Outcome measures included ankle joint proprioception measured as threshold for perception of passive movement (TPPM); single leg stance time; perceived difficulty for standing balance; usual, fastest, and narrow-path gait speed; walking index; short physical performance battery score; and self-reported activity restriction due to fear of falling. Descriptive variables included age, sex, body mass index, education, strength, and cognition. Analyses of covariance (ANCOVA) in general linear model (GLM) or multinomial logistic regression analyses were performed, as appropriate, to test the hypothesis that balance, mobility, and physical function were significantly different according to TPPM quintiles even after adjusting for relevant covariates. Those with TPPM >2.2° consistently demonstrated poor balance, mobility, and physical function. However, with increase in challenge (single leg stance, fastest walking speed, and SPPB), TPPM >1.4° was associated with significantly worse performance. In conclusion, ankle proprioceptive acuity has an overall graded relationship with objective and self-report measures of balance, mobility, and physical function. However, the cutoff proprioceptive acuity associated with substantial decline or inability to perform could depend on the challenge induced.

  13. Trigger Point Dry Needling and Proprioceptive Exercises for the Management of Chronic Ankle Instability: A Randomized Clinical Trial.

    PubMed

    Salom-Moreno, Jaime; Ayuso-Casado, Blanca; Tamaral-Costa, Beatriz; Sánchez-Milá, Zacarías; Fernández-de-Las-Peñas, César; Alburquerque-Sendín, Francisco

    2015-01-01

    Objective. To compare the effects of combined trigger point dry needling (TrP-DN) and proprioceptive/strengthening exercises to proprioceptive/strengthening exercises on pain and function in ankle instability. Methods. Twenty-seven (44% female, mean age: 33 ± 3 years) individuals with unilateral ankle instability were randomly assigned to an experimental group who received proprioceptive/strengthening exercises combined with TrP-DN into the lateral peroneus muscle and a comparison group receiving the same proprioceptive/strengthening exercise program alone. Outcome included function assessed with the Foot and Ankle Ability Measure (FAAM) and ankle pain intensity assessed with a numerical pain rate scale (NPRS). They were captured at baseline and 1-month follow-up after the intervention. Results. The ANOVAs found significant Group ∗ Time Interactions for both subscales of the FAAM (ADL: F = 8.211; P = 0.008; SPORTS: F = 13.943; P < 0.001) and for pain (F = 44.420; P < 0.001): patients receiving TrP-DN plus proprioceptive/strengthening exercises experienced greater improvements in function and pain than those receiving the exercise program alone. Between-groups effect sizes were large in all outcomes (SMD > 2.1) in favor of the TrP-DN group. Conclusions. This study provides evidence that the inclusion of TrP-DN within the lateral peroneus muscle into a proprioceptive/strengthening exercise program resulted in better outcomes in pain and function 1 month after the therapy in ankle instability. PMID:26064172

  14. Ankle proprioceptive acuity is associated with objective as well as self-report measures of balance, mobility, and physical function.

    PubMed

    Deshpande, Nandini; Simonsick, Eleanor; Metter, E Jeffrey; Ko, Seunguk; Ferrucci, Luigi; Studenski, Stephanie

    2016-06-01

    Ankle proprioceptive information is integrated by the central nervous system to generate and modulate muscle contractions for maintaining standing balance. This study evaluated the association of ankle joint proprioception with objective and self-report measures of balance, mobility, and physical function across the adult life span. Seven hundred and ninety participants (age range 24-97 years, 362 women) who completed ankle proprioception assessment between 2010 and 2014 were included in the present study from the population-based cohort of the Baltimore Longitudinal Study of Aging (BLSA), USA. Outcome measures included ankle joint proprioception measured as threshold for perception of passive movement (TPPM); single leg stance time; perceived difficulty for standing balance; usual, fastest, and narrow-path gait speed; walking index; short physical performance battery score; and self-reported activity restriction due to fear of falling. Descriptive variables included age, sex, body mass index, education, strength, and cognition. Analyses of covariance (ANCOVA) in general linear model (GLM) or multinomial logistic regression analyses were performed, as appropriate, to test the hypothesis that balance, mobility, and physical function were significantly different according to TPPM quintiles even after adjusting for relevant covariates. Those with TPPM >2.2° consistently demonstrated poor balance, mobility, and physical function. However, with increase in challenge (single leg stance, fastest walking speed, and SPPB), TPPM >1.4° was associated with significantly worse performance. In conclusion, ankle proprioceptive acuity has an overall graded relationship with objective and self-report measures of balance, mobility, and physical function. However, the cutoff proprioceptive acuity associated with substantial decline or inability to perform could depend on the challenge induced. PMID:27146830

  15. Effects of Patellar Taping on Brain Activity During Knee Joint Proprioception Tests Using Functional Magnetic Resonance Imaging

    PubMed Central

    McKie, Shane; Richardson, Paul; Oldham, Jacqueline A.

    2012-01-01

    Background Patellar taping is a common treatment modality for physical therapists managing patellofemoral pain. However, the mechanisms of action remain unclear, with much debate as to whether its efficacy is due to a change in patellar alignment or an alteration in sensory input. Objective The purpose of this study was to investigate the sensory input hypothesis using functional magnetic resonance imaging when taping was applied to the knee joint during a proprioception task. Design This was an observational study with patellar taping intervention. Methods Eight male volunteers who were healthy and right-leg dominant participated in a motor block design study. Each participant performed 2 right knee extension repetitive movement tasks: one simple and one proprioceptive. These tasks were performed with and without patellar taping and were auditorally paced for 400 seconds at 72 beats/min (1.2 Hz). Results The proprioception task without patellar taping caused a positive blood oxygenation level–dependant (BOLD) response bilaterally in the medial supplementary motor area, the cingulate motor area, the basal ganglion, and the thalamus and medial primary sensory motor cortex. For the proprioception task with patellar taping, there was a decreased BOLD response in these regions. In the lateral primary sensory cortex, there was a negative BOLD response with less activity for the proprioception task with taping. Limitations This study may have been limited by the small sample size, a possible learning effect due to a nonrandom order of tasks, and use of a single-joint knee extension task. Conclusions This study demonstrated that patellar taping modulates brain activity in several areas of the brain during a proprioception knee movement task. PMID:22282771

  16. Trigger Point Dry Needling and Proprioceptive Exercises for the Management of Chronic Ankle Instability: A Randomized Clinical Trial.

    PubMed

    Salom-Moreno, Jaime; Ayuso-Casado, Blanca; Tamaral-Costa, Beatriz; Sánchez-Milá, Zacarías; Fernández-de-Las-Peñas, César; Alburquerque-Sendín, Francisco

    2015-01-01

    Objective. To compare the effects of combined trigger point dry needling (TrP-DN) and proprioceptive/strengthening exercises to proprioceptive/strengthening exercises on pain and function in ankle instability. Methods. Twenty-seven (44% female, mean age: 33 ± 3 years) individuals with unilateral ankle instability were randomly assigned to an experimental group who received proprioceptive/strengthening exercises combined with TrP-DN into the lateral peroneus muscle and a comparison group receiving the same proprioceptive/strengthening exercise program alone. Outcome included function assessed with the Foot and Ankle Ability Measure (FAAM) and ankle pain intensity assessed with a numerical pain rate scale (NPRS). They were captured at baseline and 1-month follow-up after the intervention. Results. The ANOVAs found significant Group ∗ Time Interactions for both subscales of the FAAM (ADL: F = 8.211; P = 0.008; SPORTS: F = 13.943; P < 0.001) and for pain (F = 44.420; P < 0.001): patients receiving TrP-DN plus proprioceptive/strengthening exercises experienced greater improvements in function and pain than those receiving the exercise program alone. Between-groups effect sizes were large in all outcomes (SMD > 2.1) in favor of the TrP-DN group. Conclusions. This study provides evidence that the inclusion of TrP-DN within the lateral peroneus muscle into a proprioceptive/strengthening exercise program resulted in better outcomes in pain and function 1 month after the therapy in ankle instability.

  17. Trigger Point Dry Needling and Proprioceptive Exercises for the Management of Chronic Ankle Instability: A Randomized Clinical Trial

    PubMed Central

    Salom-Moreno, Jaime; Ayuso-Casado, Blanca; Tamaral-Costa, Beatriz; Sánchez-Milá, Zacarías; Fernández-de-las-Peñas, César; Alburquerque-Sendín, Francisco

    2015-01-01

    Objective. To compare the effects of combined trigger point dry needling (TrP-DN) and proprioceptive/strengthening exercises to proprioceptive/strengthening exercises on pain and function in ankle instability. Methods. Twenty-seven (44% female, mean age: 33 ± 3 years) individuals with unilateral ankle instability were randomly assigned to an experimental group who received proprioceptive/strengthening exercises combined with TrP-DN into the lateral peroneus muscle and a comparison group receiving the same proprioceptive/strengthening exercise program alone. Outcome included function assessed with the Foot and Ankle Ability Measure (FAAM) and ankle pain intensity assessed with a numerical pain rate scale (NPRS). They were captured at baseline and 1-month follow-up after the intervention. Results. The ANOVAs found significant Group ∗ Time Interactions for both subscales of the FAAM (ADL: F = 8.211; P = 0.008; SPORTS: F = 13.943; P < 0.001) and for pain (F = 44.420; P < 0.001): patients receiving TrP-DN plus proprioceptive/strengthening exercises experienced greater improvements in function and pain than those receiving the exercise program alone. Between-groups effect sizes were large in all outcomes (SMD > 2.1) in favor of the TrP-DN group. Conclusions. This study provides evidence that the inclusion of TrP-DN within the lateral peroneus muscle into a proprioceptive/strengthening exercise program resulted in better outcomes in pain and function 1 month after the therapy in ankle instability. PMID:26064172

  18. Design and development of proprioceptive sensors to be used for mobile robot localization

    NASA Astrophysics Data System (ADS)

    Ferrand, Andre

    Proprioceptive sensors designed for use in the localization functions of mobile robots are described. The robots for which the sensors are designed may be required to climb small obstacles or small inclined planes. The sensor system is designed to provide five localization parameters, namely three attitude angles, yaw, roll and pitch, and two parameters of position on a horizontal plane. For this purpose, an odometer with inertial sensors is used along with a gyroscope and accelerometers. The odometer works independently of the robot locomotion. The gyroscope controls the odometer's measurements during the climbing of an obstacle and, when necessary, rectifies them.

  19. Palisade endings and proprioception in extraocular muscles: a comparison with skeletal muscles.

    PubMed

    Lienbacher, Karoline; Horn, Anja K E

    2012-12-01

    This article describes current views on motor and sensory control of extraocular muscles (EOMs) based on anatomical data. The special morphology of EOMs, including their motor innervation, is described in comparison to classical skeletal limb and trunk muscles. The presence of proprioceptive organs is reviewed with emphasis on the palisade endings (PEs), which are unique to EOMs, but the function of which is still debated. In consideration of the current new anatomical data about the location of cell bodies of PEs, a hypothesis on the function of PEs in EOMs and the multiply innervated muscle fibres they are attached to is put forward.

  20. Single-subject-based whole-brain MEG slow-wave imaging approach for detecting abnormality in patients with mild traumatic brain injury.

    PubMed

    Huang, Ming-Xiong; Nichols, Sharon; Baker, Dewleen G; Robb, Ashley; Angeles, Annemarie; Yurgil, Kate A; Drake, Angela; Levy, Michael; Song, Tao; McLay, Robert; Theilmann, Rebecca J; Diwakar, Mithun; Risbrough, Victoria B; Ji, Zhengwei; Huang, Charles W; Chang, Douglas G; Harrington, Deborah L; Muzzatti, Laura; Canive, Jose M; Christopher Edgar, J; Chen, Yu-Han; Lee, Roland R

    2014-01-01

    Traumatic brain injury (TBI) is a leading cause of sustained impairment in military and civilian populations. However, mild TBI (mTBI) can be difficult to detect using conventional MRI or CT. Injured brain tissues in mTBI patients generate abnormal slow-waves (1-4 Hz) that can be measured and localized by resting-state magnetoencephalography (MEG). In this study, we develop a voxel-based whole-brain MEG slow-wave imaging approach for detecting abnormality in patients with mTBI on a single-subject basis. A normative database of resting-state MEG source magnitude images (1-4 Hz) from 79 healthy control subjects was established for all brain voxels. The high-resolution MEG source magnitude images were obtained by our recent Fast-VESTAL method. In 84 mTBI patients with persistent post-concussive symptoms (36 from blasts, and 48 from non-blast causes), our method detected abnormalities at the positive detection rates of 84.5%, 86.1%, and 83.3% for the combined (blast-induced plus with non-blast causes), blast, and non-blast mTBI groups, respectively. We found that prefrontal, posterior parietal, inferior temporal, hippocampus, and cerebella areas were particularly vulnerable to head trauma. The result also showed that MEG slow-wave generation in prefrontal areas positively correlated with personality change, trouble concentrating, affective lability, and depression symptoms. Discussion is provided regarding the neuronal mechanisms of MEG slow-wave generation due to deafferentation caused by axonal injury and/or blockages/limitations of cholinergic transmission in TBI. This study provides an effective way for using MEG slow-wave source imaging to localize affected areas and supports MEG as a tool for assisting the diagnosis of mTBI. PMID:25009772

  1. Slow motion increases perceived intent.

    PubMed

    Caruso, Eugene M; Burns, Zachary C; Converse, Benjamin A

    2016-08-16

    To determine the appropriate punishment for a harmful action, people must often make inferences about the transgressor's intent. In courtrooms and popular media, such inferences increasingly rely on video evidence, which is often played in "slow motion." Four experiments (n = 1,610) involving real surveillance footage from a murder or broadcast replays of violent contact in professional football demonstrate that viewing an action in slow motion, compared with regular speed, can cause viewers to perceive an action as more intentional. This slow motion intentionality bias occurred, in part, because slow motion video caused participants to feel like the actor had more time to act, even when they knew how much clock time had actually elapsed. Four additional experiments (n = 2,737) reveal that allowing viewers to see both regular speed and slow motion replay mitigates the bias, but does not eliminate it. We conclude that an empirical understanding of the effect of slow motion on mental state attribution should inform the life-or-death decisions that are currently based on tacit assumptions about the objectivity of human perception.

  2. Slow motion increases perceived intent

    PubMed Central

    Caruso, Eugene M.; Burns, Zachary C.; Converse, Benjamin A.

    2016-01-01

    To determine the appropriate punishment for a harmful action, people must often make inferences about the transgressor’s intent. In courtrooms and popular media, such inferences increasingly rely on video evidence, which is often played in “slow motion.” Four experiments (n = 1,610) involving real surveillance footage from a murder or broadcast replays of violent contact in professional football demonstrate that viewing an action in slow motion, compared with regular speed, can cause viewers to perceive an action as more intentional. This slow motion intentionality bias occurred, in part, because slow motion video caused participants to feel like the actor had more time to act, even when they knew how much clock time had actually elapsed. Four additional experiments (n = 2,737) reveal that allowing viewers to see both regular speed and slow motion replay mitigates the bias, but does not eliminate it. We conclude that an empirical understanding of the effect of slow motion on mental state attribution should inform the life-or-death decisions that are currently based on tacit assumptions about the objectivity of human perception. PMID:27482091

  3. Slow motion increases perceived intent.

    PubMed

    Caruso, Eugene M; Burns, Zachary C; Converse, Benjamin A

    2016-08-16

    To determine the appropriate punishment for a harmful action, people must often make inferences about the transgressor's intent. In courtrooms and popular media, such inferences increasingly rely on video evidence, which is often played in "slow motion." Four experiments (n = 1,610) involving real surveillance footage from a murder or broadcast replays of violent contact in professional football demonstrate that viewing an action in slow motion, compared with regular speed, can cause viewers to perceive an action as more intentional. This slow motion intentionality bias occurred, in part, because slow motion video caused participants to feel like the actor had more time to act, even when they knew how much clock time had actually elapsed. Four additional experiments (n = 2,737) reveal that allowing viewers to see both regular speed and slow motion replay mitigates the bias, but does not eliminate it. We conclude that an empirical understanding of the effect of slow motion on mental state attribution should inform the life-or-death decisions that are currently based on tacit assumptions about the objectivity of human perception. PMID:27482091

  4. Does Wearing Textured Insoles during Non-class Time Improve Proprioception in Professional Dancers?

    PubMed

    Steinberg, N; Tirosh, O; Adams, R; Karin, J; Waddington, G

    2015-11-01

    This study sought to determine whether textured insoles inserted in the sports shoes of young dancers improved their inversion and eversion ankle movement discrimination. 26 ballet dancers (14 female, 12 male) from the Australian Ballet School, ages 14-19 years, were divided into 2 groups according to sex and class levels. During the first 4 weeks, the first intervention group (GRP1) was asked to wear textured insoles in their sports shoes during non-class periods, and the second intervention group (GRP2) followed standard practice. In the next 4 weeks, GRP2 was asked to wear the textured insoles and GRP1 did not wear the textured insoles. Participants were tested pre-intervention, after 4 weeks, and at 8 weeks for both inversion and eversion ankle discrimination. In both inversion and eversion testing positions, interaction was found between the 2 groups and the 3 testing times (p<0.001), with significant differences between the first testing and the second testing (p=0.038 and p=0.019, respectively), and between the third testing and the second testing (p=0.003 and p=0.029, respectively). In conclusion, the stimulation to the proprioceptive system arising from textured insoles worn for 4 weeks was sufficient to improve the ankle proprioception of ballet dancers, in both inversion and eversion movements.

  5. Memantine elicits spinal blockades of motor function, proprioception, and nociception in rats.

    PubMed

    Chen, Yu-Wen; Chiu, Chong-Chi; Liu, Kuo-Sheng; Hung, Ching-Hsia; Wang, Jhi-Joung

    2015-12-01

    Although memantine blocks sodium currents and produces local skin anesthesia, spinal anesthesia with memantine is unknown. The purpose of the study was to evaluate the local anesthetic effect of memantine in spinal anesthesia and its comparison with a widely used local anesthetic lidocaine. After intrathecally injecting the rats with five doses of each drug, the dose-response curves of memantine and lidocaine were constructed. The potencies of the drugs and durations of spinal anesthetic effects on motor function, proprioception, and nociception were compared with those of lidocaine. We showed that memantine produced dose-dependent spinal blockades in motor function, proprioception, and nociception. On a 50% effective dose (ED50 ) basis, the rank of potency was lidocaine greater than memantine (P < 0.05 for the differences). At the equipotent doses (ED25 , ED50 , ED75 ), the block duration produced by memantine was longer than that produced by lidocaine (P < 0.05 for the differences). Memantine, but not lidocaine, displayed more sensory/nociceptive block than motor block. The preclinical data demonstrated that memantine is less potent than lidocaine, whereas memantine produces longer duration of spinal anesthesia than lidocaine. Memantine shows a more sensory-selective action over motor blockade. PMID:26301611

  6. The hip strength:ankle proprioceptive threshold ratio predicts falls and injury in diabetic neuropathy

    PubMed Central

    Richardson, James K.; DeMott, Trina; Allet, Lara; Kim; Ashton-Miller, James A.

    2014-01-01

    Introduction We determined lower limb neuromuscular capacities associated with falls and fall-related injuries in older people with declining peripheral nerve function. Methods Thirty-two subjects (67.4 ± 13.4 years; 19 with type 2 diabetes), representing a spectrum of peripheral neurologic function, were evaluated with frontal plane proprioceptive thresholds at the ankle, frontal plane motor function at the ankle and hip, and prospective follow-up for 1 year. Results Falls and fall-related injuries were reported by 20 (62.5%) and 14 (43.8%) subjects, respectively. The ratio of hip adductor rate of torque development to ankle proprioceptive threshold (HipSTR/AnkPRO) predicted falls (pseudo-R2 = .726) and injury (pseudo-R2 = .382). No other variable maintained significance in the presence of HipSTR/AnkPRO. Discussion Fall and injury risk in the population studied is related inversely to HipSTR/AnkPRO. Increasing rapidly available hip strength in patients with neuropathic ankle sensory impairment may decrease risk of falls and related injuries. PMID:24282041

  7. Memantine elicits spinal blockades of motor function, proprioception, and nociception in rats.

    PubMed

    Chen, Yu-Wen; Chiu, Chong-Chi; Liu, Kuo-Sheng; Hung, Ching-Hsia; Wang, Jhi-Joung

    2015-12-01

    Although memantine blocks sodium currents and produces local skin anesthesia, spinal anesthesia with memantine is unknown. The purpose of the study was to evaluate the local anesthetic effect of memantine in spinal anesthesia and its comparison with a widely used local anesthetic lidocaine. After intrathecally injecting the rats with five doses of each drug, the dose-response curves of memantine and lidocaine were constructed. The potencies of the drugs and durations of spinal anesthetic effects on motor function, proprioception, and nociception were compared with those of lidocaine. We showed that memantine produced dose-dependent spinal blockades in motor function, proprioception, and nociception. On a 50% effective dose (ED50 ) basis, the rank of potency was lidocaine greater than memantine (P < 0.05 for the differences). At the equipotent doses (ED25 , ED50 , ED75 ), the block duration produced by memantine was longer than that produced by lidocaine (P < 0.05 for the differences). Memantine, but not lidocaine, displayed more sensory/nociceptive block than motor block. The preclinical data demonstrated that memantine is less potent than lidocaine, whereas memantine produces longer duration of spinal anesthesia than lidocaine. Memantine shows a more sensory-selective action over motor blockade.

  8. The robot hand illusion: inducing proprioceptive drift through visuo-motor congruency.

    PubMed

    Romano, Daniele; Caffa, Elisa; Hernandez-Arieta, Alejandro; Brugger, Peter; Maravita, Angelo

    2015-04-01

    The representation of one's own body sets the border of the self, but also shapes the space where we interact with external objects. Under particular conditions, such as in the rubber hand illusion external objects can be incorporated in one's own body representation, following congruent visuo-tactile stroking of one's own and a fake hand. This procedure induces an illusory sense of ownership for the fake hand and a shift of proprioceptive localization of the own hand towards the fake hand. Here we investigated whether pure visuo-motor, instead of visuo-tactile, congruency between one's own hand and a detached myoelectric-controlled robotic hand can induce similar embodiment effects. We found a shift of proprioceptive hand localization toward the robot hand, only following synchronized real hand/robot hand movements. Notably, no modulation was found of the sense of ownership following either synchronous or asynchronous-movement training. Our findings suggest that visuo-motor synchrony can drive the localization of one's own body parts in space, even when somatosensory input is kept constant and the experience of body ownership is maintained.

  9. Somatic experiencing: using interoception and proprioception as core elements of trauma therapy

    PubMed Central

    Payne, Peter; Levine, Peter A.; Crane-Godreau, Mardi A.

    2015-01-01

    Here we present a theory of human trauma and chronic stress, based on the practice of Somatic Experiencing® (SE), a form of trauma therapy that emphasizes guiding the client's attention to interoceptive, kinesthetic, and proprioceptive experience. SE™ claims that this style of inner attention, in addition to the use of kinesthetic and interoceptive imagery, can lead to the resolution of symptoms resulting from chronic and traumatic stress. This is accomplished through the completion of thwarted, biologically based, self-protective and defensive responses, and the discharge and regulation of excess autonomic arousal. We present this theory through a composite case study of SE treatment; based on this example, we offer a possible neurophysiological rationale for the mechanisms involved, including a theory of trauma and chronic stress as a functional dysregulation of the complex dynamical system formed by the subcortical autonomic, limbic, motor and arousal systems, which we term the core response network (CRN). We demonstrate how the methods of SE help restore functionality to the CRN, and we emphasize the importance of taking into account the instinctive, bodily based protective reactions when dealing with stress and trauma, as well as the effectiveness of using attention to interoceptive, proprioceptive and kinesthetic sensation as a therapeutic tool. Finally, we point out that SE and similar somatic approaches offer a supplement to cognitive and exposure therapies, and that mechanisms similar to those discussed in the paper may also be involved in the benefits of meditation and other somatic practices. PMID:25699005

  10. Abnormal Pressure Pain, Touch Sensitivity, Proprioception, and Manual Dexterity in Children with Autism Spectrum Disorders

    PubMed Central

    Riquelme, Inmaculada; Hatem, Samar M.

    2016-01-01

    Children with autism spectrum disorders (ASD) often display an abnormal reactivity to tactile stimuli, altered pain perception, and lower motor skills than healthy children. Nevertheless, these motor and sensory deficits have been mostly assessed by using clinical observation and self-report questionnaires. The present study aims to explore somatosensory and motor function in children with ASD by using standardized and objective testing procedures. Methods. Tactile and pressure pain thresholds in hands and lips, stereognosis, proprioception, and fine motor performance of the upper limbs were assessed in high-functioning children with ASD (n = 27) and compared with typically developing peers (n = 30).  Results. Children with ASD showed increased pain sensitivity, increased touch sensitivity in C-tactile afferents innervated areas, and diminished fine motor performance and proprioception compared to healthy children. No group differences were observed for stereognosis. Conclusion. Increased pain sensitivity and increased touch sensitivity in areas classically related to affective touch (C-tactile afferents innervated areas) may explain typical avoiding behaviors associated with hypersensitivity. Both sensory and motor impairments should be assessed and treated in children with ASD. PMID:26881091

  11. The effect of interventional proprioceptive training on static balance and gait in deaf children.

    PubMed

    Majlesi, Mahdi; Farahpour, Nader; Azadian, Elaheh; Amini, Mahdi

    2014-12-01

    Children with hearing impairment have balance and motor deficits primarily due to concomitant damage to the vestibular structures. Although early intervention focused on the development of communication skills, investigations of intervention for the amelioration of balance deficits in children with hearing loss have been minimal and inconclusive. Therefore, using an experimental design, the present study investigated the effect of a 12-session exercise balance program based on proprioception training on balance and gait in deaf as compared with hearing schoolchildren. The subjects, 10 deaf and 10 typically developing children were assigned to an experimental and a control group respectively. Taking up the initial differences between the groups through a pretest under different conditions, the participants in the experimental group went through a 12-session intervention program including static and dynamic training with emphasis on proprioceptive system. After this, the participants were tested again. The data obtained was analyzed using repeated measure. A comparison between the control and experimental groups revealed that the intervention program had not significantly increased gait velocity while it had significantly decreased the amount of sway. Thus, it was concluded that an exercise program that enhances somatosensory ability can result in improved balance in deaf children.

  12. [Cervicogenic proprioceptive vertigo: etiopathogenesis, clinical manifestations, diagnosis and therapy with special emphasis on manual therapy].

    PubMed

    Grgić, Vjekoslav

    2006-01-01

    Cervical proprioceptive system (CPS) consisting of mechanoreceptors of cervical intervertebral joints, mechanoreceptors of neck muscles and ligament's insertions, muscle spindles located in deep short muscles of cervical spine and sensitive fibers connecting neck's proprioceptors with neurons of cornu posteriori of spinal cord, plays an essential part in maintaining bodily balance. CPS, via tractus spinovestibularis, is connected to vestibular nuclei. Clinical and neurophysiological studies have shown that functional disorders and/or organic lesions of CPS cause identical symptoms as vestibular diseases: vertigo, nystagmus and balance disorders. Dysfunction (functional blockade) of craniocervical joints is the most frequent cause of cervicogenic proprioceptive vertigo (CPV). The constant tension of the capsule of a blocked joint irritates mechanoreceptors protecting the joint's capsules. The increased activity of mechanoreceptors results in confusion of vestibular system. That is, the impulses from the blocked craniocervical joints do not correspond to the impulses from the vestibular organ and other sensory systems that take part in maintaining bodily balance. The disharmony of impulses results in an inadequate vestibulo-spinal and vestibulo-ocular reaction manifesting as vertigo and nystagmus. Hyperactivity of craniocervical mechanoreceptors also causes disturbances in reflex regulation of postural muscle tonus manifesting as "general instability". Knowledge of CPV as a separate clinical entity is important from diagnostical and therapeutical aspect. As it concerns a peripheral vestibular disorder still unknown to a wider circle of physicians, the article describes etiopathogenesis, clinical manifestations, diagnosis and therapy of CPV with special emphasis on manual therapy.

  13. Effect of Time after Anterior Cruciate Ligament Tears on Proprioception and Postural Stability

    PubMed Central

    Lee, Dae-Hee; Lee, Jin-Hyuck; Ahn, Sung-Eun; Park, Min-Ji

    2015-01-01

    This study was designed to compare proprioception and postural stability in patients with acute (time from injury ≤ 3 months) and chronic (time from injury > 3 months) ACL tears, and to evaluate the correlation between time interval after ACL injury and proprioception. Thigh muscle strength, postural stability, and joint position sense were compared in 48 patients with acute ACL tears and in 28 with chronic ACL tears. Maximal torque (60°/sec) of the quadriceps and hamstring was evaluated using an isokinetic testing device. Postural stability was determined from the anterior-posterior (APSI), medial-lateral (MLSI), and overall (OSI) stability indices using stabilometry. Joint position sense was also tested by reproduction of passive positioning (RPP). Muscle strengths and stability indices on both the involved and uninvolved sides were similar in the acute and chronic ACL tear groups. RPP on the involved side was significantly greater in the chronic than in the acute ACL tear group (7.8° vs. 5.6°, P = 0.041). Two of three stability indices (APSI, OSI) and RPP were significantly greater on the involved than the uninvolved side in the chronic ACL tear group. PMID:26422800

  14. Postural muscle atrophy prevention and recovery and bone remodelling through high frequency proprioception for astronauts

    NASA Astrophysics Data System (ADS)

    Riva, Dario; Rossitto, Franco; Battocchio, Luciano

    2009-09-01

    The difficulty in applying active exercises during space flights increases the importance of passive countermeasures, but coupling load and instability remains indispensable for generating high frequency (HF) proprioceptive flows and preventing muscle atrophy and osteoporosis. The present study, in microgravity conditions during a parabolic flight, verified whether an electronic system, composed of a rocking board, a postural reader and a bungee-cord loading apparatus creates HF postural instability comparable to that reachable on the Earth. Tracking the subject, in single stance, to real-time visual signals is necessary to obtain HF instability situations. The bungee-cord loading apparatus allowed the subject to manage the 81.5% body weight load (100% could easily be exceeded). A preliminary training programme schedule on the Earth and in space is suggested. Comparison with a pathological muscle atrophy is presented. The possibility of generating HF proprioceptive flows could complement current countermeasures for the prevention and recovery of muscle atrophy and osteoporosis in terrestrial and space environments. These exercises combine massive activation of spindles and joint receptors, applying simultaneously HF variations of pressure to different areas of the sole of the foot. This class of exercises could improve the effectiveness of current countermeasures, reducing working time and fatigue.

  15. Origin of a Non-Clarke's Column Division of the Dorsal Spinocerebellar Tract and the Role of Caudal Proprioceptive Neurons in Motor Function.

    PubMed

    Yuengert, Rachel; Hori, Kei; Kibodeaux, Erin E; McClellan, Jacob X; Morales, Justin E; Huang, Teng-Wei P; Neul, Jeffrey L; Lai, Helen C

    2015-11-10

    Proprioception, the sense of limb and body position, is essential for generating proper movement. Unconscious proprioceptive information travels through cerebellar-projecting neurons in the spinal cord and medulla. The progenitor domain defined by the basic-helix-loop-helix (bHLH) transcription factor, ATOH1, has been implicated in forming these cerebellar-projecting neurons; however, their precise contribution to proprioceptive tracts and motor behavior is unknown. Significantly, we demonstrate that Atoh1-lineage neurons in the spinal cord reside outside Clarke's column (CC), a main contributor of neurons relaying hindlimb proprioception, despite giving rise to the anatomical and functional correlate of CC in the medulla, the external cuneate nucleus (ECu), which mediates forelimb proprioception. Elimination of caudal Atoh1-lineages results in mice with relatively normal locomotion but unable to perform coordinated motor tasks. Altogether, we reveal that proprioceptive nuclei in the spinal cord and medulla develop from more than one progenitor source, suggesting an avenue to uncover distinct proprioceptive functions.

  16. Acute effect of scapular proprioceptive neuromuscular facilitation (PNF) techniques and classic exercises in adhesive capsulitis: a randomized controlled trial.

    PubMed

    Balcı, Nilay Comuk; Yuruk, Zeliha Ozlem; Zeybek, Aslican; Gulsen, Mustafa; Tekindal, Mustafa Agah

    2016-04-01

    [Purpose] The aim of our study was to compare the initial effects of scapular proprioceptive neuromuscular facilitation techniques and classic exercise interventions with physiotherapy modalities on pain, scapular dyskinesis, range of motion, and function in adhesive capsulitis. [Subjects and Methods] Fifty-three subjects were allocated to 3 groups: scapular proprioceptive neuromuscular facilitation exercies and physiotherapy modalities, classic exercise and physiotherapy modalities, and only physiotherapy modalities. The intervention was applied in a single session. The Visual Analog Scale, Lateral Scapular Slide Test, range of motion and Simple Shoulder Test were evaluated before and just after the one-hour intervention in the same session (all in one session). [Results] All of the groups showed significant differences in shoulder flexion and abduction range of motion and Simple Shoulder Test scores. There were statistically significant differences in Visual Analog Scale scores in the proprioceptive neuromuscular facilitation and control groups, and no treatment method had significant effect on the Lateral Scapular Slide Test results. There were no statistically significant differences between the groups before and after the intervention. [Conclusion] Proprioceptive neuromuscular facilitation, classic exercise, and physiotherapy modalities had immediate effects on adhesive capsulitis in our study. However, there was no additional benefit of exercises in one session over physiotherapy modalities. Also, an effective treatment regimen for shoulder rehabilitation of adhesive capsulitis patients should include scapular exercises.

  17. The Relative Efficacy of Vestibular-Proprioceptive Stimulation and the Upright Position in Enhancing Visual Pursuit in Neonates

    ERIC Educational Resources Information Center

    Gregg, Claudette L.; And Others

    1976-01-01

    Forty-eight neonates were randomly assigned to view a moving stimulus either in the horizontal or the upright position, with or without added vestibular stimulation and with or without pacifier sucking. Results indicate that vestibular proprioceptive stimulation, provided horizontally or semi-vertically, significantly enhanced visual tracking.…

  18. Effects of age and non-oropharyngeal proprioceptive and exteroceptive sensation on the magnitude of anticipatory mouth opening during eating.

    PubMed

    Shune, S E; Moon, J B

    2016-09-01

    To best prevent and treat eating/swallowing problems, it is essential to understand how components of oral physiology contribute to the preservation and/or degradation of eating/swallowing in healthy ageing. Anticipatory, pre-swallow motor movements may be critical to safe and efficient eating/swallowing, particularly for older adults. However, the nature of these responses is relatively unknown. This study compared the magnitude of anticipatory mouth opening during eating in healthy older (aged 70-85) and younger (aged 18-30) adults under four eating conditions: typical self-feeding, typical assisted feeding (being fed by a research assistant resulting in proprioceptive loss), sensory loss self-feeding (wearing blindfold/headphones resulting in exteroceptive loss) and sensory loss assisted feeding (proprioceptive and exteroceptive loss). Older adults opened their mouths wider than younger adults in anticipation of food intake under both typical and most non-oropharyngeal sensory loss conditions. Further, the loss of proprioceptive and exteroceptive cues resulted in decreased anticipatory mouth opening for all participants. Greater mouth opening in older adults may be a protective compensation, contributing to the preservation of function associated with healthy ageing. Our finding that the loss of non-oropharyngeal sensory cues resulted in decreased anticipatory mouth opening highlights how important proprioception, vision, and hearing are in pre-swallow behaviour. Age- and disease-related changes in vision, hearing, and the ability to self-feed may reduce the effectiveness of these pre-swallow strategies. PMID:27377757

  19. Acute effect of scapular proprioceptive neuromuscular facilitation (PNF) techniques and classic exercises in adhesive capsulitis: a randomized controlled trial

    PubMed Central

    Balcı, Nilay Comuk; Yuruk, Zeliha Ozlem; Zeybek, Aslican; Gulsen, Mustafa; Tekindal, Mustafa Agah

    2016-01-01

    [Purpose] The aim of our study was to compare the initial effects of scapular proprioceptive neuromuscular facilitation techniques and classic exercise interventions with physiotherapy modalities on pain, scapular dyskinesis, range of motion, and function in adhesive capsulitis. [Subjects and Methods] Fifty-three subjects were allocated to 3 groups: scapular proprioceptive neuromuscular facilitation exercies and physiotherapy modalities, classic exercise and physiotherapy modalities, and only physiotherapy modalities. The intervention was applied in a single session. The Visual Analog Scale, Lateral Scapular Slide Test, range of motion and Simple Shoulder Test were evaluated before and just after the one-hour intervention in the same session (all in one session). [Results] All of the groups showed significant differences in shoulder flexion and abduction range of motion and Simple Shoulder Test scores. There were statistically significant differences in Visual Analog Scale scores in the proprioceptive neuromuscular facilitation and control groups, and no treatment method had significant effect on the Lateral Scapular Slide Test results. There were no statistically significant differences between the groups before and after the intervention. [Conclusion] Proprioceptive neuromuscular facilitation, classic exercise, and physiotherapy modalities had immediate effects on adhesive capsulitis in our study. However, there was no additional benefit of exercises in one session over physiotherapy modalities. Also, an effective treatment regimen for shoulder rehabilitation of adhesive capsulitis patients should include scapular exercises. PMID:27190456

  20. Effects of age and non-oropharyngeal proprioceptive and exteroceptive sensation on the magnitude of anticipatory mouth opening during eating.

    PubMed

    Shune, S E; Moon, J B

    2016-09-01

    To best prevent and treat eating/swallowing problems, it is essential to understand how components of oral physiology contribute to the preservation and/or degradation of eating/swallowing in healthy ageing. Anticipatory, pre-swallow motor movements may be critical to safe and efficient eating/swallowing, particularly for older adults. However, the nature of these responses is relatively unknown. This study compared the magnitude of anticipatory mouth opening during eating in healthy older (aged 70-85) and younger (aged 18-30) adults under four eating conditions: typical self-feeding, typical assisted feeding (being fed by a research assistant resulting in proprioceptive loss), sensory loss self-feeding (wearing blindfold/headphones resulting in exteroceptive loss) and sensory loss assisted feeding (proprioceptive and exteroceptive loss). Older adults opened their mouths wider than younger adults in anticipation of food intake under both typical and most non-oropharyngeal sensory loss conditions. Further, the loss of proprioceptive and exteroceptive cues resulted in decreased anticipatory mouth opening for all participants. Greater mouth opening in older adults may be a protective compensation, contributing to the preservation of function associated with healthy ageing. Our finding that the loss of non-oropharyngeal sensory cues resulted in decreased anticipatory mouth opening highlights how important proprioception, vision, and hearing are in pre-swallow behaviour. Age- and disease-related changes in vision, hearing, and the ability to self-feed may reduce the effectiveness of these pre-swallow strategies.

  1. Slow rupture of frictional interfaces

    NASA Astrophysics Data System (ADS)

    Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

    2012-02-01

    The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

  2. Effects of 12-week proprioception training program on postural stability, gait, and balance in older adults: a controlled clinical trial.

    PubMed

    Martínez-Amat, Antonio; Hita-Contreras, Fidel; Lomas-Vega, Rafael; Caballero-Martínez, Isabel; Alvarez, Pablo J; Martínez-López, Emilio

    2013-08-01

    The purpose of this study was to evaluate the effect of a 12-week-specific proprioceptive training program on postural stability, gait, balance, and fall prevention in adults older than 65 years. The present study was a controlled clinical trial. Forty-four community dwelling elderly subjects (61-90 years; mean age, 78.07 ± 5.7 years) divided into experimental (n = 20) and control (n = 24) groups. The participants performed the Berg balance test before and after the training program, and we assessed participants' gait, balance, and the risk of falling, using the Tinetti scale. Medial-lateral plane and anterior-posterior plane displacements of the center of pressure, Sway area, length and speed, and the Romberg quotient about surface, speed, and distance were calculated in static posturography analysis (EPS pressure platform) under 2 conditions: eyes open and eyes closed. After a first clinical evaluation, patients were submitted to 12 weeks proprioception training program, 2 sessions of 50 minutes every week. This program includes 6 exercises with the BOSU and Swiss ball as unstable training tools that were designed to program proprioceptive training. The training program improved postural balance of older adults in mediolateral plane with eyes open (p < 0.05) and anterior-posterior plane with eyes closed (p < 0.01). Significant improvements were observed in Romberg quotient about surface (p < 0.05) and speed (p < 0.01) but not about distance (p > 0.05). After proprioception training, gait (Tinetti), and balance (Berg) test scores improved 14.66% and 11.47% respectively. These results show that 12 weeks proprioception training program in older adults is effective in postural stability, static, and dynamic balance and could lead to an improvement in gait and balance capacity, and to a decrease in the risk of falling in adults aged 65 years and older.

  3. FEL on slow cyclotron wave

    SciTech Connect

    Silivra, A.

    1995-12-31

    A physical mechanism of interaction of fast electromagnetic wave with slow cyclotron wave of relativistic electron beam in a FEL with helical wiggler field is described. It is shown that: (1) interaction is possible for both group of steady state electron trajectories (2) positive gain is achieved within certain interval of guide field strength (3) operation wavelength for group 1 trajectories ({Omega}{sub 0}/{gamma} < k{omega}{upsilon}{parallel}) is shorter than for the conventional FEL synchronism. A nonlinear analysis shows that efficiency of slow cyclotron FEL is restricted mainly by a breakdown of a single electron synchronism due to dependence of (modified) electron cyclotron frequency on an energy of electron. Nevertheless, as numerical simulation shows, typical efficiency of 15 % order is achieved in millimeter wavelength band for the midrelativistic ({gamma}= 3 {divided_by} 4) slow cyclotron wave FEL. Tapering of magnetic field results in a substantial increase of efficiency.

  4. The role of vestibular and support-tactile-proprioceptive inputs in visual-manual tracking

    NASA Astrophysics Data System (ADS)

    Kornilova, Ludmila; Naumov, Ivan; Glukhikh, Dmitriy; Khabarova, Ekaterina; Pavlova, Aleksandra; Ekimovskiy, Georgiy; Sagalovitch, Viktor; Smirnov, Yuriy; Kozlovskaya, Inesa

    Sensorimotor disorders in weightlessness are caused by changes of functioning of gravity-dependent systems, first of all - vestibular and support. The question arises, what’s the role and the specific contribution of the support afferentation in the development of observed disorders. To determine the role and effects of vestibular, support, tactile and proprioceptive afferentation on characteristics of visual-manual tracking (VMT) we conducted a comparative analysis of the data obtained after prolonged spaceflight and in a model of weightlessness - horizontal “dry” immersion. Altogether we examined 16 Russian cosmonauts before and after prolonged spaceflights (129-215 days) and 30 subjects who stayed in immersion bath for 5-7 days to evaluate the state of the vestibular function (VF) using videooculography and characteristics of the visual-manual tracking (VMT) using electrooculography & joystick with biological visual feedback. Evaluation of the VF has shown that both after immersion and after prolonged spaceflight there were significant decrease of the static torsional otolith-cervical-ocular reflex (OCOR) and simultaneous significant increase of the dynamic vestibular-cervical-ocular reactions (VCOR) with a revealed negative correlation between parameters of the otoliths and canals reactions, as well as significant changes in accuracy of perception of the subjective visual vertical which correlated with changes in OCOR. Analyze of the VMT has shown that significant disorders of the visual tracking (VT) occurred from the beginning of the immersion up to 3-4 day after while in cosmonauts similar but much more pronounced oculomotor disorders and significant changes from the baseline were observed up to R+9 day postflight. Significant changes of the manual tracking (MT) were revealed only for gain and occurred on 1 and 3 days in immersion while after spaceflight such changes were observed up to R+5 day postflight. We found correlation between characteristics

  5. Development of Proprioceptive Acuity in Typically Developing Children: Normative Data on Forearm Position Sense.

    PubMed

    Holst-Wolf, Jessica M; Yeh, I-Ling; Konczak, Jürgen

    2016-01-01

    This study mapped the development of proprioception in healthy, typically developing children by objectively measuring forearm position sense acuity. We assessed position sense acuity in a cross-sectional sample of 308 children (5-17 years old; M/F = 127/181) and a reference group of 26 healthy adults (18-25 years old; M/F = 12/14) using a body-scalable bimanual manipulandum that allowed forearm flexion/extension in the horizontal plane. The non-dominant forearm was passively displaced to one of three target positions. Then participants actively matched the target limb position with their dominant forearm. Each of three positions was matched five times. Position error (PE), calculated as the mean difference between the angular positions of the matching and reference arms, measured position sense bias or systematic error. The respective standard deviation of the differences between the match and reference arm angular positions (SDPdiff) indicated position sense precision or random error. The main results are as follows: First, systematic error, measured by PE, did not change significantly from early childhood to late adolescence (Median PE at 90° target: -2.85° in early childhood; -2.28° in adolescence; and 1.30° in adults). Second, response variability as measured by SDPdiff significantly decreased with age (Median SDPdiff at 90° target: 9.66° in early childhood; 5.30° in late adolescence; and 3.97° in adults). The data of this large cross-sectional sample of children document that proprioceptive development in typically developing children is characterized as an age-related improvement in precision, not as a development or change in bias. In other words, it is the reliability of the perceptual response that improves between early childhood and adulthood. This study provides normative data against which position sense acuity in pediatric patient populations can be compared. The underlying neurophysiological processes that could explain the observed

  6. Development of Proprioceptive Acuity in Typically Developing Children: Normative Data on Forearm Position Sense

    PubMed Central

    Holst-Wolf, Jessica M.; Yeh, I-Ling; Konczak, Jürgen

    2016-01-01

    This study mapped the development of proprioception in healthy, typically developing children by objectively measuring forearm position sense acuity. We assessed position sense acuity in a cross-sectional sample of 308 children (5–17 years old; M/F = 127/181) and a reference group of 26 healthy adults (18–25 years old; M/F = 12/14) using a body-scalable bimanual manipulandum that allowed forearm flexion/extension in the horizontal plane. The non-dominant forearm was passively displaced to one of three target positions. Then participants actively matched the target limb position with their dominant forearm. Each of three positions was matched five times. Position error (PE), calculated as the mean difference between the angular positions of the matching and reference arms, measured position sense bias or systematic error. The respective standard deviation of the differences between the match and reference arm angular positions (SDPdiff) indicated position sense precision or random error. The main results are as follows: First, systematic error, measured by PE, did not change significantly from early childhood to late adolescence (Median PE at 90° target: −2.85° in early childhood; −2.28° in adolescence; and 1.30° in adults). Second, response variability as measured by SDPdiff significantly decreased with age (Median SDPdiff at 90° target: 9.66° in early childhood; 5.30° in late adolescence; and 3.97° in adults). The data of this large cross-sectional sample of children document that proprioceptive development in typically developing children is characterized as an age-related improvement in precision, not as a development or change in bias. In other words, it is the reliability of the perceptual response that improves between early childhood and adulthood. This study provides normative data against which position sense acuity in pediatric patient populations can be compared. The underlying neurophysiological processes that could explain the observed

  7. Development of Proprioceptive Acuity in Typically Developing Children: Normative Data on Forearm Position Sense

    PubMed Central

    Holst-Wolf, Jessica M.; Yeh, I-Ling; Konczak, Jürgen

    2016-01-01

    This study mapped the development of proprioception in healthy, typically developing children by objectively measuring forearm position sense acuity. We assessed position sense acuity in a cross-sectional sample of 308 children (5–17 years old; M/F = 127/181) and a reference group of 26 healthy adults (18–25 years old; M/F = 12/14) using a body-scalable bimanual manipulandum that allowed forearm flexion/extension in the horizontal plane. The non-dominant forearm was passively displaced to one of three target positions. Then participants actively matched the target limb position with their dominant forearm. Each of three positions was matched five times. Position error (PE), calculated as the mean difference between the angular positions of the matching and reference arms, measured position sense bias or systematic error. The respective standard deviation of the differences between the match and reference arm angular positions (SDPdiff) indicated position sense precision or random error. The main results are as follows: First, systematic error, measured by PE, did not change significantly from early childhood to late adolescence (Median PE at 90° target: −2.85° in early childhood; −2.28° in adolescence; and 1.30° in adults). Second, response variability as measured by SDPdiff significantly decreased with age (Median SDPdiff at 90° target: 9.66° in early childhood; 5.30° in late adolescence; and 3.97° in adults). The data of this large cross-sectional sample of children document that proprioceptive development in typically developing children is characterized as an age-related improvement in precision, not as a development or change in bias. In other words, it is the reliability of the perceptual response that improves between early childhood and adulthood. This study provides normative data against which position sense acuity in pediatric patient populations can be compared. The underlying neurophysiological processes that could explain the observed

  8. Uniform silicon slow light waveguide

    NASA Astrophysics Data System (ADS)

    Jiang, C.

    2011-01-01

    An uniform silicon waveguide is proposed featuring ultralow-dispersion slow light. The core of the waveguide consists of one silicon trip and two pairs of air/silicon strip and the cladding is composed of several alternative silicon and air strips, which form a transverse band gap to confine propagating light in the core. The waveguide has several nearly linear photonic bands in a large frequency range, which can support broadband slow modes with a group velocity of 0.03-0.08 c and tolerable group velocity dispersion.

  9. Slow Images and Entangled Photons

    SciTech Connect

    Swordy, Simon

    2007-06-20

    I will discuss some recent experiments using slow light and entangled photons. We recently showed that it was possible to map a two dimensional image onto very low light level signals, slow them down in a hot atomic vapor while preserving the amplitude and phase of the images. If time remains, I will discuss some of our recent work with time-energy entangled photons for quantum cryptography. We were able to show that we could have a measurable state space of over 1000 states for a single pair of entangled photons in fiber.

  10. Slow Crack Growth of Germanium

    NASA Technical Reports Server (NTRS)

    Salem, Jon

    2016-01-01

    The fracture toughness and slow crack growth parameters of germanium supplied as single crystal beams and coarse grain disks were measured. Although germanium is anisotropic (A=1.7), it is not as anisotropic as SiC, NiAl, or Cu, as evidence by consistent fracture toughness on the 100, 110, and 111 planes. Germanium does not exhibit significant slow crack growth in distilled water. (n=100). Practical values for engineering design are a fracture toughness of 0.7 MPam and a Weibull modulus of m=6+/-2. For well ground and reasonable handled coupons, fracture strength should be greater than 30 MPa.

  11. Slow beams of massive molecules

    NASA Astrophysics Data System (ADS)

    Deachapunya, S.; Fagan, P. J.; Major, A. G.; Reiger, E.; Ritsch, H.; Stefanov, A.; Ulbricht, H.; Arndt, M.

    2008-02-01

    Slow beams of neutral molecules are of great interest for a wide range of applications, from cold chemistry through precision measurements to tests of the foundations of quantum mechanics. We report on the quantitative observation of thermal beams of perfluorinated macromolecules with masses up to 6000 amu, reaching velocities down to 11 m/s. Such slow, heavy and neutral molecular beams are of importance for a new class of experiments in matter-wave interferometry and we also discuss the requirements for further manipulation and cooling schemes with molecules in this unprecedented mass range.

  12. Slow shocks around the sun

    NASA Technical Reports Server (NTRS)

    Whang, Y. C.

    1982-01-01

    It is inferred from this study that magnetohydrodynamic slow shocks can exist in the vicinity of the sun. The study uses a two-hole corona model, the sub-Alfvenic streams originating from the edge of the polar open-field regions are forced to turn towards equator in coronal space following the curved boundary of the closed field region. When the streamlines from the opposite poles merge at a neutral point, their directions become parallel to the neutral sheet. An oblique slow shock can develop near or at the neutral point, the shock extends polewards to form a surface of discontinuity around the sun.

  13. Stochastic dynamics on slow manifolds

    NASA Astrophysics Data System (ADS)

    Constable, George W. A.; McKane, Alan J.; Rogers, Tim

    2013-07-01

    The theory of slow manifolds is an important tool in the study of deterministic dynamical systems, giving a practical method by which to reduce the number of relevant degrees of freedom in a model, thereby often resulting in a considerable simplification. In this paper we demonstrate how the same basic methodology may also be applied to stochastic dynamical systems, by examining the behaviour of trajectories conditioned on the event that they do not depart the slow manifold. We apply the method to two models: one from ecology and one from epidemiology, achieving a reduction in model dimension and illustrating the high quality of the analytical approximations.

  14. Correlation between head posture and proprioceptive function in the cervical region

    PubMed Central

    Yong, Min-Sik; Lee, Hae-Yong; Lee, Mi-Young

    2016-01-01

    [Purpose] The aim of the present study was to investigate correlation between head posture and proprioceptive function in the cervical region. [Subjects and Methods] Seventy-two subjects (35 males and 37 females) participated in this study. For measurement of head posture, the craniovertebral angle was calculated based on the angle between a horizontal line passing through C7 and a line extending from the tragus of the ear to C7. The joint position sense was evaluated using a dual digital inclinometer (Acumar, Lafayette Instrument, Lafayette, IN, USA), which was used to measure the joint position error for cervical flexion and extension. [Results] A significant negative correlation was observed between the craniovertebral angle and position sense error for flexion and extension. [Conclusion] Forward head posture is correlated with greater repositioning error than a more upright posture, and further research is needed to determine whether correction of forward head posture has any impact on repositioning error. PMID:27134372

  15. Differences in proprioceptive senses between children with diplegic and children with hemiplegic cerebral palsy.

    PubMed

    Ryu, Hyo Jeong; Song, Gui-Bin

    2016-01-01

    [Purpose] In the present study, in order to examine the differences in proprioceptive senses between children with diplegic CP and children with hemiplegic CP, neck reposition errors were measured. [Subjects and Methods] Head reposition senses were measured after neck flexion, extension, and left-right rotation, using head repositioning accuracy tests. These tests were done with 12 children with diplegic CP and nine children with hemiplegic CP. [Results] The results indicated that children with diplegic CP had poorer head repositioning senses after movements in all directions compared to children with hemiplegic CP. [Conclusion] The results indicated that children with diplegic CP had poorer head repositioning senses after movements in all directions as compared to children with hemiplegic CP.

  16. Differences in proprioceptive senses between children with diplegic and children with hemiplegic cerebral palsy

    PubMed Central

    Ryu, Hyo Jeong; Song, Gui-bin

    2016-01-01

    [Purpose] In the present study, in order to examine the differences in proprioceptive senses between children with diplegic CP and children with hemiplegic CP, neck reposition errors were measured. [Subjects and Methods] Head reposition senses were measured after neck flexion, extension, and left-right rotation, using head repositioning accuracy tests. These tests were done with 12 children with diplegic CP and nine children with hemiplegic CP. [Results] The results indicated that children with diplegic CP had poorer head repositioning senses after movements in all directions compared to children with hemiplegic CP. [Conclusion] The results indicated that children with diplegic CP had poorer head repositioning senses after movements in all directions as compared to children with hemiplegic CP. PMID:27065559

  17. Reading and the Slow Learner.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Advocates of high standards and expectations usually believe that gaps in reading achievement can be eliminated with good teaching, but slow readers need a specially designed reading curriculum. The teacher first needs to use an informal reading inventory to determine the student's reading level. Functioning generally on a higher level than…

  18. Fast wandering of slow birds

    NASA Astrophysics Data System (ADS)

    Toner, John

    2011-12-01

    I study a single slow bird moving with a flock of birds of a different and faster (or slower) species. I find that every species of flocker has a characteristic speed γ≠v0, where v0 is the mean speed of the flock such that if the speed vs of the slow bird equals γ, it will randomly wander transverse to the mean direction of flock motion far faster than the other birds will: Its mean-squared transverse displacement will grow in d=2 with time t like t5/3, in contrast to t4/3 for the other birds. In d=3, the slow bird's mean-squared transverse displacement grows like t5/4, in contrast to t for the other birds. If vs≠γ, the mean-squared displacement of the slow bird crosses over from t5/3 to t4/3 scaling in d=2 and from t5/4 to t scaling in d=3 at a time tc that scales according to tc∝|vs-γ|-2.

  19. Haptic stabilization of posture: changes in arm proprioception and cutaneous feedback for different arm orientations

    NASA Technical Reports Server (NTRS)

    Rabin, E.; Bortolami, S. B.; DiZio, P.; Lackner, J. R.

    1999-01-01

    Postural sway during quiet stance is attenuated by actively maintained contact of the index finger with a stationary surface, even if the level of applied force (<1 N) cannot provide mechanical stabilization. In this situation, changes in force level at the fingertip lead changes in center of foot pressure by approximately 250 ms. These and related findings indicate that stimulation of the fingertip combined with proprioceptive information about the hand and arm can serve as an active sensor of body position relative to the point of contact. A geometric analysis of the relationship between hand and torso displacement during body sway led to the prediction that arm and hand proprioceptive and finger somatosensory information about body sway would be maximized with finger contact in the plane of body sway. Therefore, the most postural stabilization should be possible with such contact. To test this analysis, subjects touched a laterally versus anteriorly placed surface while in each of two stances: the heel-to-toe tandem Romberg stance that reduces medial-lateral stability and the heel-to-heel, toes-outward, knees-bent, "duck stance" that reduces fore-aft stability. Postural sway was always least with finger contact in the unstable plane: for the tandem stance, lateral fingertip contact was significantly more effective than frontal contact, and, for the duck stance, frontal contact was more effective than lateral fingertip contact. Force changes at the fingertip led changes in center of pressure of the feet by approximately 250 ms for both fingertip contact locations for both test stances. These results support the geometric analysis, which showed that 1) arm joint angles change by the largest amount when fingertip contact is maintained in the plane of greatest sway, and 2) the somatosensory cues at the fingertip provide both direction and amplitude information about sway when the finger is contacting a surface in the unstable plane.

  20. Cortico-muscular synchronization by proprioceptive afferents from the tongue muscles during isometric tongue protrusion.

    PubMed

    Maezawa, Hitoshi; Mima, Tatsuya; Yazawa, Shogo; Matsuhashi, Masao; Shiraishi, Hideaki; Funahashi, Makoto

    2016-03-01

    Tongue movements contribute to oral functions including swallowing, vocalizing, and breathing. Fine tongue movements are regulated through efferent and afferent connections between the cortex and tongue. It has been demonstrated that cortico-muscular coherence (CMC) is reflected at two frequency bands during isometric tongue protrusions: the beta (β) band at 15-35Hz and the low-frequency band at 2-10Hz. The CMC at the β band (β-CMC) reflects motor commands from the primary motor cortex (M1) to the tongue muscles through hypoglossal motoneuron pools. However, the generator mechanism of the CMC at the low-frequency band (low-CMC) remains unknown. Here, we evaluated the mechanism of low-CMC during isometric tongue protrusion using magnetoencephalography (MEG). Somatosensory evoked fields (SEFs) were also recorded following electrical tongue stimulation. Significant low-CMC and β-CMC were observed over both hemispheres for each side of the tongue. Time-domain analysis showed that the MEG signal followed the electromyography signal for low-CMC, which was contrary to the finding that the MEG signal preceded the electromyography signal for β-CMC. The mean conduction time from the tongue to the cortex was not significantly different between the low-CMC (mean, 80.9ms) and SEFs (mean, 71.1ms). The cortical sources of low-CMC were located significantly posterior (mean, 10.1mm) to the sources of β-CMC in M1, but were in the same area as tongue SEFs in the primary somatosensory cortex (S1). These results reveal that the low-CMC may be driven by proprioceptive afferents from the tongue muscles to S1, and that the oscillatory interaction was derived from each side of the tongue to both hemispheres. Oscillatory proprioceptive feedback from the tongue muscles may aid in the coordination of sophisticated tongue movements in humans.

  1. Sensory reweighting dynamics following removal and addition of visual and proprioceptive cues.

    PubMed

    Assländer, Lorenz; Peterka, Robert J

    2016-08-01

    Removing or adding sensory cues from one sensory system during standing balance causes a change in the contribution of the remaining sensory systems, a process referred to as sensory reweighting. While reweighting changes have been described in many studies under steady-state conditions, less is known about the temporal dynamics of reweighting following sudden transitions to different sensory conditions. The present study changed sensory conditions by periodically adding or removing visual (lights On/Off) or proprioceptive cues (surface sway referencing On/Off) in 12 young, healthy subjects. Evidence for changes in sensory contributions to balance was obtained by measuring the time course of medial-lateral sway responses to a constant-amplitude 0.56-Hz sinusoidal stimulus, applied as support surface tilt (proprioceptive contribution), as visual scene tilt (visual contribution), or as binaural galvanic vestibular stimulation (vestibular contribution), and by analyzing the time course of sway variability. Sine responses and variability of body sway velocity showed significant changes following transitions and were highly correlated under steady-state conditions. A dependence of steady-state responses on upcoming transitions was observed, suggesting that knowledge of impending changes can influence sensory weighting. Dynamic changes in sway in the period immediately following sensory transitions were very inhomogeneous across sway measures and in different experimental tests. In contrast to steady-state results, sway response and variability measures were not correlated with one another in the dynamic transition period. Several factors influence sway responses following addition or removal of sensory cues, partly instigated by but also obscuring the effects of reweighting dynamics.

  2. Central syntropic effects elicited by trigeminal proprioceptive equilibrium in Alzheimer’s disease: a case report

    PubMed Central

    2012-01-01

    Introduction The presented patient, affected by Alzheimer’s disease, underwent neuropsychological evaluation and functional magnetic resonance imaging investigation under occlusal proprioceptive un-balance and re-balance conditions. Saccadic and pupillometric video-oculographic examinations were performed in order to detect connected trigeminal proprioceptive motor patterns able to interfere with reticular formation cerebellum functions linked to visual and procedural processes prematurely altered in Alzheimer’s disease. Case presentation A 66-year-old Caucasian man, affected by Alzheimer’s disease and with a neuropsychological evaluation issued by the Alzheimer’s Evaluation Unit, underwent an electromyographic investigation of the masseter muscles in order to assess their functional balance. The patient showed a bilateral lack of all inferior molars. The extreme myoelectric asymmetry in dental occlusion suggested the rebalancing of masseter muscular functions through concurrent transcutaneous stimulation of the trigeminal nerve supramandibular and submandibular motor branches. The above-mentioned method allows detection of symmetric craniomandibular muscular relation that can be kept constant through the use of a cusp bite modeled on the inferior dental arch, called orthotic-syntropic bite. A few days later, the patient underwent a new neuropsychological investigation, together with a functional magnetic resonance imaging study, and saccadic, pupillometric video-oculographic examinations in occlusal un-balance and re-balance conditions. Conclusions Comparative data analysis has shown that a re-balanced occlusal condition can improve a patient’s cognitive-attentive functions. Moreover, the saccadic and pupillometric video-oculographic investigations have proven useful both in analyzing reticulo-cerebellar subcortical systems, prematurely altered in Alzheimer’s disease, and in implementing neurological evaluations. PMID:22734831

  3. Proprioceptive Localization of the Hand Changes When Skin Stretch around the Elbow Is Manipulated

    PubMed Central

    Kuling, Irene A.; Brenner, Eli; Smeets, Jeroen B. J.

    2016-01-01

    Cutaneous information has been shown to influence proprioceptive position sense when subjects had to judge or match the posture of their limbs. In the present study, we tested whether cutaneous information also affects proprioceptive localization of the hand when moving it to a target. In an explorative study, we manipulated the skin stretch around the elbow by attaching elastic sports tape to one side of the arm. Subjects were asked to move the unseen manipulated arm to visually presented targets. We found that the tape induced a significant shift of the end-points of these hand movements. Surprisingly, this shift corresponded with an increase in elbow extension, irrespective of the side of the arm that was taped. A control experiment showed that this cannot be explained by how the skin stretches, because the skin near the elbow stretches to a similar extent on the inside and outside of the arm when the elbow angle increases and decreases, respectively. A second control experiment reproduced and extended the results of the main experiment for tape on the inside of the arm, and showed that the asymmetry was not just a consequence of the tape originally being applied slightly differently to the outside of the arm. However, the way in which the tape was applied does appear to matter, because applying the tape in the same way to the outside of the arm as to the inside of the arm influenced different subjects quite differently, suggesting that the relationship between skin stretch and sensed limb posture is quite complex. We conclude that the way the skin is stretched during a goal-directed movement provides information that helps guide the hand toward the target.

  4. Visual, motor and attentional influences on proprioceptive contributions to perception of hand path rectilinearity during reaching

    PubMed Central

    Scheidt, Robert A.; Lillis, Kyle P.; Emerson, Scott J.

    2010-01-01

    We examined how proprioceptive contributions to perception of hand path straightness are influenced by visual, motor and attentional sources of performance variability during horizontal planar reaching. Subjects held the handle of a robot that constrained goal-directed movements of the hand to paths of controlled curvature. Subjects attempted to detect the presence of hand path curvature during both active (subject-driven) and passive (robot-driven) movements that either required active muscle force production or not. Subjects were less able to discriminate curved from straight paths when actively reaching for a target vs. when the robot moved their hand through the same curved paths. This effect was especially evident during robot-driven movements requiring concurrent activation of lengthening but not shortening muscles. Subjects were less likely to report curvature and were more variable in reporting when movements appeared straight in a novel “visual channel” condition previously shown to block adaptive updating of motor commands in response to deviations from a straight-line hand path. Similarly compromised performance was obtained when subjects simultaneously performed a distracting secondary task (key pressing with the contralateral hand). The effects compounded when these last two treatments were combined. It is concluded that environmental, intrinsic and attentional factors all impact the ability to detect deviations from a rectilinear hand path during goal-directed movement by decreasing proprioceptive contributions to limb state estimation. In contrast, response variability increased only in experimental conditions thought to impose additional attentional demands on the observer. Implications of these results for perception and other sensorimotor behaviors are discussed. PMID:20532489

  5. Visuo-proprioceptive interactions in degenerative cervical spine diseases requiring surgery.

    PubMed

    Freppel, S; Bisdorff, A; Colnat-Coulbois, S; Ceyte, H; Cian, C; Gauchard, G; Auque, J; Perrin, P

    2013-01-01

    Cervical proprioception plays a key role in postural control, but its specific contribution is controversial. Postural impairment was shown in whiplash injuries without demonstrating the sole involvement of the cervical spine. The consequences of degenerative cervical spine diseases are underreported in posture-related scientific literature in spite of their high prevalence. No report has focused on the two different mechanisms underlying cervicobrachial pain: herniated discs and spondylosis. This study aimed to evaluate postural control of two groups of patients with degenerative cervical spine diseases with or without optokinetic stimulation before and after surgical treatment. Seventeen patients with radiculopathy were recruited and divided into two groups according to the spondylotic or discal origin of the nerve compression. All patients and a control population of 31 healthy individuals underwent a static posturographic test with 12 recordings; the first four recordings with the head in 0° position: eyes closed, eyes open without optokinetic stimulation, with clockwise and counter clockwise optokinetic stimulations. These four sensorial situations were repeated with the head rotated 30° to the left and to the right. Patients repeated these 12 recordings 6weeks postoperatively. None of the patients reported vertigo or balance disorders before or after surgery. Prior to surgery, in the eyes closed condition, the herniated disc group was more stable than the spondylosis group. After surgery, the contribution of visual input to postural control in a dynamic visual environment was reduced in both cervical spine diseases whereas in a stable visual environment visual contribution was reduced only in the spondylosis group. The relative importance of visual and proprioceptive inputs to postural control varies according to the type of pathology and surgery tends to reduce visual contribution mostly in the spondylosis group.

  6. Multisensory Tracking of Objects in Darkness: Capture of Positive Afterimages by the Tactile and Proprioceptive Senses

    PubMed Central

    Stone, Brian W.; Tinker, Jessica

    2016-01-01

    This paper reports on three experiments investigating the contribution of different sensory modalities to the tracking of objects moved in total darkness. Participants sitting in the dark were exposed to a brief, bright flash which reliably induced a positive visual afterimage of the scene so illuminated. If the participants subsequently move their hand in the darkness, the visual afterimage of that hand fades or disappears; this is presumably due to conflict between the illusory visual afterimage (of the hand in its original location) and other information (e.g., proprioceptive) from a general mechanism for tracking body parts. This afterimage disappearance effect also occurs for held objects which are moved in the dark, and some have argued that this represents a case of body schema extension, i.e. the rapid incorporation of held external objects into the body schema. We demonstrate that the phenomenon is not limited to held objects and occurs in conditions where incorporation into the body schema is unlikely. Instead, we propose that the disappearance of afterimages of objects moved in darkness comes from a general mechanism for object tracking which integrates input from multiple sensory systems. This mechanism need not be limited to tracking body parts, and thus we need not invoke body schema extension to explain the afterimage disappearance. In this series of experiments, we test whether auditory feedback of object movement can induce afterimage disappearance, demonstrate that the disappearance effect scales with the magnitude of proprioceptive feedback, and show that tactile feedback alone is sufficient for the effect. Together, these data demonstrate that the visual percept of a positive afterimage is constructed not just from visual input of the scene when light reaches the eyes, but in conjunction with input from multiple other senses. PMID:26959233

  7. A Single-Session Preliminary Evaluation of an Affordable BCI-Controlled Arm Exoskeleton and Motor-Proprioception Platform.

    PubMed

    Elnady, Ahmed Mohamed; Zhang, Xin; Xiao, Zhen Gang; Yong, Xinyi; Randhawa, Bubblepreet Kaur; Boyd, Lara; Menon, Carlo

    2015-01-01

    Traditional, hospital-based stroke rehabilitation can be labor-intensive and expensive. Furthermore, outcomes from rehabilitation are inconsistent across individuals and recovery is hard to predict. Given these uncertainties, numerous technological approaches have been tested in an effort to improve rehabilitation outcomes and reduce the cost of stroke rehabilitation. These techniques include brain-computer interface (BCI), robotic exoskeletons, functional electrical stimulation (FES), and proprioceptive feedback. However, to the best of our knowledge, no studies have combined all these approaches into a rehabilitation platform that facilitates goal-directed motor movements. Therefore, in this paper, we combined all these technologies to test the feasibility of using a BCI-driven exoskeleton with FES (robotic training device) to facilitate motor task completion among individuals with stroke. The robotic training device operated to assist a pre-defined goal-directed motor task. Because it is hard to predict who can utilize this type of technology, we considered whether the ability to adapt skilled movements with proprioceptive feedback would predict who could learn to control a BCI-driven robotic device. To accomplish this aim, we developed a motor task that requires proprioception for completion to assess motor-proprioception ability. Next, we tested the feasibility of robotic training system in individuals with chronic stroke (n = 9) and found that the training device was well tolerated by all the participants. Ability on the motor-proprioception task did not predict the time to completion of the BCI-driven task. Both participants who could accurately target (n = 6) and those who could not (n = 3), were able to learn to control the BCI device, with each BCI trial lasting on average 2.47 min. Our results showed that the participants' ability to use proprioception to control motor output did not affect their ability to use the BCI-driven exoskeleton

  8. A Single-Session Preliminary Evaluation of an Affordable BCI-Controlled Arm Exoskeleton and Motor-Proprioception Platform

    PubMed Central

    Elnady, Ahmed Mohamed; Zhang, Xin; Xiao, Zhen Gang; Yong, Xinyi; Randhawa, Bubblepreet Kaur; Boyd, Lara; Menon, Carlo

    2015-01-01

    Traditional, hospital-based stroke rehabilitation can be labor-intensive and expensive. Furthermore, outcomes from rehabilitation are inconsistent across individuals and recovery is hard to predict. Given these uncertainties, numerous technological approaches have been tested in an effort to improve rehabilitation outcomes and reduce the cost of stroke rehabilitation. These techniques include brain–computer interface (BCI), robotic exoskeletons, functional electrical stimulation (FES), and proprioceptive feedback. However, to the best of our knowledge, no studies have combined all these approaches into a rehabilitation platform that facilitates goal-directed motor movements. Therefore, in this paper, we combined all these technologies to test the feasibility of using a BCI-driven exoskeleton with FES (robotic training device) to facilitate motor task completion among individuals with stroke. The robotic training device operated to assist a pre-defined goal-directed motor task. Because it is hard to predict who can utilize this type of technology, we considered whether the ability to adapt skilled movements with proprioceptive feedback would predict who could learn to control a BCI-driven robotic device. To accomplish this aim, we developed a motor task that requires proprioception for completion to assess motor-proprioception ability. Next, we tested the feasibility of robotic training system in individuals with chronic stroke (n = 9) and found that the training device was well tolerated by all the participants. Ability on the motor-proprioception task did not predict the time to completion of the BCI-driven task. Both participants who could accurately target (n = 6) and those who could not (n = 3), were able to learn to control the BCI device, with each BCI trial lasting on average 2.47 min. Our results showed that the participants’ ability to use proprioception to control motor output did not affect their ability to use the BCI

  9. Microstructural Integrity of the Superior Cerebellar Peduncle Is Associated with an Impaired Proprioceptive Weighting Capacity in Individuals with Non-Specific Low Back Pain

    PubMed Central

    Pijnenburg, Madelon; Caeyenberghs, Karen; Janssens, Lotte; Goossens, Nina; Swinnen, Stephan P.; Sunaert, Stefan; Brumagne, Simon

    2014-01-01

    Introduction Postural control is a complex sensorimotor task that requires an intact network of white matter connections. The ability to weight proprioceptive signals is crucial for postural control. However, research into central processing of proprioceptive signals for postural control is lacking. This is specifically of interest in individuals with non-specific low back pain (NSLBP), because impairments in postural control have been observed as possible underlying mechanisms of NSLBP. Therefore, the objective was to investigate potential differences in sensorimotor white matter microstructure between individuals with NSLBP and healthy controls, and to determine whether the alterations in individuals with NSLBP are associated with the capacity to weight proprioceptive signals for postural control. Methods The contribution of proprioceptive signals from the ankle and back muscles to postural control was evaluated by local muscle vibration in 18 individuals with NSLBP and 18 healthy controls. Center of pressure displacement in response to muscle vibration was determined during upright standing on a stable and unstable support surface. Diffusion magnetic resonance imaging was applied to examine whether this proprioceptive contribution was associated with sensorimotor white matter microstructure. Results Individuals with NSLBP showed a trend towards a reduced fractional anisotropy along the left superior cerebellar peduncle compared to healthy controls (p = 0.039). The impaired microstructural integrity of the superior cerebellar peduncle in individuals with NSLBP was significantly correlated with the response to ankle muscle vibration (p<0.003). Conclusions In individuals with NSLBP, a decreased integrity of the superior cerebellar peduncle was associated with an increased reliance on ankle muscle proprioception, even on unstable support surface, which implies an impaired proprioceptive weighting capacity. Our findings emphasize the importance of the superior

  10. Sex-specific age associations of ankle proprioception test performance in older adults: results from the Baltimore Longitudinal Study of Aging

    PubMed Central

    Ko, Seung-Uk; Simonsick, Eleanor; Deshpande, Nandini; Ferrucci, Luigi

    2015-01-01

    Objectives: this study was aimed to test the hypothesis that ankle proprioception assessed by custom-designed proprioception testing equipment changes with ageing in men and women. Methods: ankle proprioception was assessed in 289 participants (131 women) of the Baltimore Longitudinal Study of Aging (BLSA); the participants aged 51–95 years and were blinded during testing. Results: the average minimum perceived ankle rotation was 1.11° (SE = 0.07) in women and 1.00° (SE = 0.06) in men, and it increased with ageing in both sexes (P < 0.001, for both). Ankle tracking performance, which is the ability to closely follow with the left ankle, a rotational movement induced on the right ankle by a torque motor, declines with ageing in both men and women (P = 0.018 and P = 0.011, respectively). Conclusions: a simple, standardised method for assessing ankle proprioception was introduced in this study using a customized test instrument, software and test protocol. Age-associated reduction in ankle proprioception was confirmed from two subtests of threshold and tracking separately for women and men. Findings in this study prompt future studies to determine whether these age-associated differences in the threshold for passive motion detection and movement tracking are evident in longitudinal study and how these specific deficits in ankle proprioception are related to age-associated chronic conditions such as knee or hip osteoarthritis and type II diabetes and affect daily activities such as gait. PMID:25637144

  11. Slow-roll thawing quintessence

    SciTech Connect

    Chiba, Takeshi

    2009-04-15

    We derive slow-roll conditions for thawing quintessence. We solve the equation of motion of {phi} for a Taylor expanded potential (up to the quadratic order) in the limit where the equation of state w is close to -1 to derive the equation of state as a function of the scale factor. We find that the evolution of {phi} and hence w are described by only two parameters. The expression for w(a), which can be applied to general thawing models, coincides precisely with that derived recently by Dutta and Scherrer for hilltop quintessence. The consistency conditions of |w+1|<<1 are derived. The slow-roll conditions for freezing quintessence are also derived.

  12. Slow extraction at the SSC

    SciTech Connect

    Colton, E.P.

    1985-01-01

    Resonant slow extraction at the SSC will permit fixed-target operation. Stochastic extraction appears to be a promising technique for achieving spill times of the order of 1000 s. However, systematic sextupole error fields in the SSC dipoles must be reduced a factor of twenty from the design values; otherwise the extraction process will be perturbed or suppressed. In addition, good regulation of the SSC power supplies is essential for smooth extraction over the spill period. 10 refs., 1 fig.

  13. Slow Conduction in Cardiac Muscle

    PubMed Central

    Lieberman, Melvyn; Kootsey, J. Mailen; Johnson, Edward A.; Sawanobori, Tohru

    1973-01-01

    Mechanisms of slow conduction in cardiac muscle are categorized and the most likely identified. Propagating action potentials were obtained experimentally from a synthetically grown strand of cardiac muscle (around 50 μm by 30 mm) and theoretically from a one-dimensional cable model that incorporated varying axial resistance and membrane properties along its length. Action potentials propagated at about 0.3 m/s, but in some synthetic strands there were regions (approximately 100 μm in length) where the velocity decreased to 0.002 m/s. The electrophysiological behavior associated with this slow conduction was similar to that associated with slow conduction in naturally occurring cardiac muscle (notches, Wenckebach phenomena, and block). Theoretically, reasonable changes in specific membrane capacitance, membrane activity, and various changes in geometry were insufficient to account for the observed slow conduction velocities. Conduction velocities as low as 0.009 m/s, however, could be obtained by increasing the resistance (ri) of connections between the cells in the cable; velocities as low as 0.0005 m/s could be obtained by a further increase in ri made possible by a reduction in membrane activity by one-fourth, which in itself decreased conduction velocity by only a factor of 1/1.4. As a result of these findings, several of the mechanisms that have been postulated, previously, are shown to be incapable of accounting for delays such as those which occur in the synthetic strand as well as in the atrioventricular (VA) node. ImagesFIGURE 1FIGURE 2FIGURE 3FIGURE 4 PMID:4709519

  14. Slow-roll extended quintessence

    SciTech Connect

    Chiba, Takeshi; Siino, Masaru; Yamaguchi, Masahide

    2010-04-15

    We derive the slow-roll conditions for a nonminimally coupled scalar field (extended quintessence) during the radiation/matter dominated era extending our previous results for thawing quintessence. We find that the ratio {phi}e/3H{phi} becomes constant but negative, in sharp contrast to the ratio for the minimally coupled scalar field. We also find that the functional form of the equation of state of the scalar field asymptotically approaches that of the minimally coupled thawing quintessence.

  15. Slow light and saturable absorption

    NASA Astrophysics Data System (ADS)

    Selden, A. C.

    2009-06-01

    Quantitative analysis of slow light experiments utilising coherent population oscillation (CPO) in a range of saturably absorbing media, including ruby and alexandrite, Er3+:Y2SiO5, bacteriorhodopsin, semiconductor quantum devices and erbium-doped optical fibres, shows that the observations may be more simply interpreted as saturable absorption phenomena. A basic two-level model of a saturable absorber displays all the effects normally associated with slow light, namely phase shift and modulation gain of the transmitted signal, hole burning in the modulation frequency spectrum and power broadening of the spectral hole, each arising from the finite response time of the non-linear absorption. Only where hole-burning in the optical spectrum is observed (using independent pump and probe beams), or pulse delays exceeding the limits set by saturable absorption are obtained, can reasonable confidence be placed in the observation of slow light in such experiments. Superluminal (“fast light”) phenomena in media with reverse saturable absorption (RSA) may be similarly explained.

  16. The effects of prone bridge exercise on the Oswestry disability index and proprioception of patients with chronic low back pain.

    PubMed

    Kong, Yong-Soo; Jang, Gwon-Uk; Park, Seol

    2015-09-01

    [Purpose] The purpose of this study was to investigate the effect of bridge exercises on the Oswestry disability index (ODI) scores and proprioception among patients with chronic low back pain (CLBP). [Subjects and Methods] A total of 38 patients participated in this study. After eight weeks of bridge exercise, the joint position angle of the body trunk was measured and the ODI was used in survey form to investigate the intensity of the patients' low back pain. [Results] After eight weeks of exercise, the ODI showed significant differences in all three groups. Subjects' joint position sense of the trunk in both lumbar flexion and extension was also significantly different after completing the exercise program; this was true for all three groups. [Conclusion] Performing the prone bridge exercise for eight weeks improved proprioceptive function and reduced pain and impediment of activity, showing it a more effective exercise than other bridge exercises.

  17. Comparison of the effects of hamstring stretching using proprioceptive neuromuscular facilitation with prior application of cryotherapy or ultrasound therapy.

    PubMed

    Magalhães, Francisco Elezier Xavier; Junior, Arlindo Rodrigues de Mesquita; Meneses, Harnold's Tyson de Sousa; Moreira Dos Santos, Rayele Pricila; Rodrigues, Ezaine Costa; Gouveia, Samara Sousa Vasconcelos; Gouveia, Guilherme Pertinni de Morais; Orsini, Marco; Bastos, Victor Hugo do Vale; Machado, Dionis de Castro Dutra

    2015-05-01

    [Purpose] Stretching using proprioceptive neuromuscular facilitation involve physiological reflex mechanisms through submaximal contraction of agonists which activate Golgi organ, promoting the relaxation reflex. The aim of this study was to evaluate the effects of proprioceptive neuromuscular facilitation alone and with prior application of cryotherapy and thermotherapy on hamstring stretching. [Subjects and Methods] The sample comprised of 32 young subjects with hamstring retraction of the right limb. The subjects were randomly allocated to four groups: the control, flexibility PNF, flexibility PNF associated with cryotherapy, flexibility PNF in association with ultrasound therapy. [Results] After 12 stretching sessions, experimental groups showed significant improvements compared to the control group. Moreover, we did not find any significant differences among the experimental groups indicating PNF stretching alone elicits similar results to PNF stretching with prior administration of cryotherapy or thermotherapy. [Conclusion] PNF without other therapy may be a more practical and less expensive choice for clinical care.

  18. Visual discrimination of delayed self-generated movement reveals the temporal limit of proprioceptive-visual intermodal integration.

    PubMed

    Jaime, Mark; O'Driscoll, Kelly; Moore, Chris

    2016-07-01

    This study examined the intermodal integration of visual-proprioceptive feedback via a novel visual discrimination task of delayed self-generated movement. Participants performed a goal-oriented task in which visual feedback was available only via delayed videos displayed on two monitors-each with different delay durations. During task performance, delay duration was varied for one of the videos in the pair relative to a standard delay, which was held constant. Participants were required to identify and use the video with the lesser delay to perform the task. Visual discrimination of the lesser-delayed video was examined under four conditions in which the standard delay was increased for each condition. A temporal limit for proprioceptive-visual intermodal integration of 3-5s was revealed by subjects' inability to reliably discriminate video pairs.

  19. The effects of prone bridge exercise on the Oswestry disability index and proprioception of patients with chronic low back pain.

    PubMed

    Kong, Yong-Soo; Jang, Gwon-Uk; Park, Seol

    2015-09-01

    [Purpose] The purpose of this study was to investigate the effect of bridge exercises on the Oswestry disability index (ODI) scores and proprioception among patients with chronic low back pain (CLBP). [Subjects and Methods] A total of 38 patients participated in this study. After eight weeks of bridge exercise, the joint position angle of the body trunk was measured and the ODI was used in survey form to investigate the intensity of the patients' low back pain. [Results] After eight weeks of exercise, the ODI showed significant differences in all three groups. Subjects' joint position sense of the trunk in both lumbar flexion and extension was also significantly different after completing the exercise program; this was true for all three groups. [Conclusion] Performing the prone bridge exercise for eight weeks improved proprioceptive function and reduced pain and impediment of activity, showing it a more effective exercise than other bridge exercises. PMID:26504285

  20. The effects of prone bridge exercise on the Oswestry disability index and proprioception of patients with chronic low back pain

    PubMed Central

    Kong, Yong-Soo; Jang, Gwon-Uk; Park, Seol

    2015-01-01

    [Purpose] The purpose of this study was to investigate the effect of bridge exercises on the Oswestry disability index (ODI) scores and proprioception among patients with chronic low back pain (CLBP). [Subjects and Methods] A total of 38 patients participated in this study. After eight weeks of bridge exercise, the joint position angle of the body trunk was measured and the ODI was used in survey form to investigate the intensity of the patients’ low back pain. [Results] After eight weeks of exercise, the ODI showed significant differences in all three groups. Subjects’ joint position sense of the trunk in both lumbar flexion and extension was also significantly different after completing the exercise program; this was true for all three groups. [Conclusion] Performing the prone bridge exercise for eight weeks improved proprioceptive function and reduced pain and impediment of activity, showing it a more effective exercise than other bridge exercises. PMID:26504285

  1. Comparison of the effects of hamstring stretching using proprioceptive neuromuscular facilitation with prior application of cryotherapy or ultrasound therapy

    PubMed Central

    Magalhães, Francisco Elezier Xavier; Junior, Arlindo Rodrigues de Mesquita; Meneses, Harnold’s Tyson de Sousa; Moreira dos Santos, Rayele Pricila; Rodrigues, Ezaine Costa; Gouveia, Samara Sousa Vasconcelos; Gouveia, Guilherme Pertinni de Morais; Orsini, Marco; Bastos, Victor Hugo do Vale; Machado, Dionis de Castro Dutra

    2015-01-01

    [Purpose] Stretching using proprioceptive neuromuscular facilitation involve physiological reflex mechanisms through submaximal contraction of agonists which activate Golgi organ, promoting the relaxation reflex. The aim of this study was to evaluate the effects of proprioceptive neuromuscular facilitation alone and with prior application of cryotherapy and thermotherapy on hamstring stretching. [Subjects and Methods] The sample comprised of 32 young subjects with hamstring retraction of the right limb. The subjects were randomly allocated to four groups: the control, flexibility PNF, flexibility PNF associated with cryotherapy, flexibility PNF in association with ultrasound therapy. [Results] After 12 stretching sessions, experimental groups showed significant improvements compared to the control group. Moreover, we did not find any significant differences among the experimental groups indicating PNF stretching alone elicits similar results to PNF stretching with prior administration of cryotherapy or thermotherapy. [Conclusion] PNF without other therapy may be a more practical and less expensive choice for clinical care. PMID:26157261

  2. Target Selection of Proprioceptive and Motor Axon Synapses on Neonatal V1-Derived Ia Inhibitory Interneurons and Renshaw Cells

    PubMed Central

    Siembab, Valerie C.; Smith, Courtney A.; Zagoraiou, Laskaro; Berrocal, Maria C.; Mentis, George Z.; Alvarez, Francisco J.

    2011-01-01

    The diversity of premotor interneurons in the mammalian spinal cord is generated from a few phylogenetically conserved embryonic classes of interneurons (V0, V1, V2, V3). Their mechanisms of diversification remain unresolved, although these are clearly important to understand motor circuit assembly in the spinal cord. Some Ia inhibitory interneurons (IaINs) and all Renshaw cells (RCs) derive from embryonic V1 interneurons; however, in adult they display distinct functional properties and synaptic inputs, for example proprioceptive inputs preferentially target IaINs, while motor axons target RCs. Previously, we found that both inputs converge on RCs in neonates, raising the possibility that proprioceptive (VGLUT1-positive) and motor axon synapses (VAChT-positive) initially target several different V1 interneurons populations and then become selected or deselected postnatally. Alternatively, specific inputs might precisely connect only with predefined groups of V1 interneurons. To test these hypotheses we analyzed synaptic development on V1-derived IaINs and compared them to RCs of the same age and spinal cord levels. V1-interneurons were labeled using genetically encoded lineage markers in mice. The results show that although neonatal V1-derived IaINs and RCs are competent to receive proprioceptive synapses, these synapses preferentially target the proximal somato-dendritic regions of IaINs and postnatally proliferate on IaINs, but not on RCs. In contrast, cholinergic synapses on RCs are specifically derived from motor axons, while on IaINs they originate from Pitx2 V0c interneurons. Thus, motor, proprioceptive, and even some interneuron inputs are biased toward specific subtypes of V1-interneurons. Postnatal strengthening of these inputs is later superimposed on this initial preferential targeting. PMID:20963823

  3. Sensorimotor control of gait: a novel approach for the study of the interplay of visual and proprioceptive feedback.

    PubMed

    Frost, Ryan; Skidmore, Jeffrey; Santello, Marco; Artemiadis, Panagiotis

    2015-01-01

    Sensorimotor control theories propose that the central nervous system exploits expected sensory consequences generated by motor commands for movement planning, as well as online sensory feedback for comparison with expected sensory feedback for monitoring and correcting, if needed, ongoing motor output. In our study, we tested this theoretical framework by quantifying the functional role of expected vs. actual proprioceptive feedback for planning and regulation of gait in humans. We addressed this question by using a novel methodological approach to deliver fast perturbations of the walking surface stiffness, in conjunction with a virtual reality system that provided visual feedback of upcoming changes of surface stiffness. In the "predictable" experimental condition, we asked subjects to learn associating visual feedback of changes in floor stiffness (sand patch) during locomotion to quantify kinematic and kinetic changes in gait prior to and during the gait cycle. In the "unpredictable" experimental condition, we perturbed floor stiffness at unpredictable instances during the gait to characterize the gait-phase dependent strategies in recovering the locomotor cycle. For the "unpredictable" conditions, visual feedback of changes in floor stiffness was absent or inconsistent with tactile and proprioceptive feedback. The investigation of these perturbation-induced effects on contralateral leg kinematics revealed that visual feedback of upcoming changes in floor stiffness allows for both early (preparatory) and late (post-perturbation) changes in leg kinematics. However, when proprioceptive feedback is not available, the early responses in leg kinematics do not occur while the late responses are preserved although in a, slightly attenuated form. The methods proposed in this study and the preliminary results of the kinematic response of the contralateral leg open new directions for the investigation of the relative role of visual, tactile, and proprioceptive feedback

  4. Impact of altered lower limb proprioception produced by tendon vibration on adaptation to split-belt treadmill walking.

    PubMed

    Layne, Charles S; Chelette, Amber M; Pourmoghaddam, Amir

    2015-01-01

    It has been proposed that proprioceptive input is essential to the development of a locomotor body schema that is used to guide the assembly of successful walking. Proprioceptive information is used to signal the need for, and promotion of, locomotor adaptation in response to environmental or internal modifications. The purpose of this investigation was to determine if tendon vibration applied to either the hamstrings or quadriceps of participants experiencing split-belt treadmill walking modified lower limb kinematics during the early adaptation period. Modifications in the adaptive process in response to vibration would suggest that the sensory-motor system had been unsuccessful in down weighting the disruptive proprioceptive input resulting from vibration. Ten participants experienced split-belt walking, with and without vibration, while gait kinematics were obtained with a 12-camera collection system. Bilateral hip, knee, and ankle joint angles were calculated and the first five strides after the split were averaged for each subject to create joint angle waveforms for each of the assessed joints, for each experimental condition. The intralimb variables of stride length, percent stance time, and relative timing between various combinations of peak joint angles were assessed using repeated measures MANOVA. Results indicate that vibration had very little impact on the split-belt walking adaptive process, although quadriceps vibration did significantly reduce percent stance time by 1.78% relative to the no vibration condition. The data suggest that the perceptual-motor system was able to down weight the disrupted proprioceptive input such that the locomotor body schema was able to effectively manage the lower limb patterns of motion necessary to adapt to the changing belt speed. Complementary explanations for the current findings are also discussed.

  5. Sensorimotor control of gait: a novel approach for the study of the interplay of visual and proprioceptive feedback

    PubMed Central

    Frost, Ryan; Skidmore, Jeffrey; Santello, Marco; Artemiadis, Panagiotis

    2015-01-01

    Sensorimotor control theories propose that the central nervous system exploits expected sensory consequences generated by motor commands for movement planning, as well as online sensory feedback for comparison with expected sensory feedback for monitoring and correcting, if needed, ongoing motor output. In our study, we tested this theoretical framework by quantifying the functional role of expected vs. actual proprioceptive feedback for planning and regulation of gait in humans. We addressed this question by using a novel methodological approach to deliver fast perturbations of the walking surface stiffness, in conjunction with a virtual reality system that provided visual feedback of upcoming changes of surface stiffness. In the “predictable” experimental condition, we asked subjects to learn associating visual feedback of changes in floor stiffness (sand patch) during locomotion to quantify kinematic and kinetic changes in gait prior to and during the gait cycle. In the “unpredictable” experimental condition, we perturbed floor stiffness at unpredictable instances during the gait to characterize the gait-phase dependent strategies in recovering the locomotor cycle. For the “unpredictable” conditions, visual feedback of changes in floor stiffness was absent or inconsistent with tactile and proprioceptive feedback. The investigation of these perturbation-induced effects on contralateral leg kinematics revealed that visual feedback of upcoming changes in floor stiffness allows for both early (preparatory) and late (post-perturbation) changes in leg kinematics. However, when proprioceptive feedback is not available, the early responses in leg kinematics do not occur while the late responses are preserved although in a, slightly attenuated form. The methods proposed in this study and the preliminary results of the kinematic response of the contralateral leg open new directions for the investigation of the relative role of visual, tactile, and

  6. The effects of ankle joint muscle strengthening and proprioceptive exercise programs accompanied by functional electrical stimulation on stroke patients’ balance

    PubMed Central

    Kim, Kyunghoon; Lee, Sukmin; Kim, Donghoon; Kim, Kyou Sik

    2015-01-01

    [Purpose] The purpose of the present study was to examine the effects of ankle joint muscle strengthening and proprioceptive exercises accompanied by functional electrical stimulation on stroke patients’ balance ability. [Methods] For six weeks beginning in April 2015, 22 stroke patients receiving physical therapy at K Hospital located in Gyeonggi-do were divided into a functional electrical stimulation (FES), ankle proprioceptive exercise and ankle joint muscle strengthening exercise group (FPS group) of 11 patients and an FES and stretching exercise group (FS group) of 11 patients. The stimulation and exercises were conducted for 30 min per day, five days per week for six weeks. Balance ability was measured using a BioRescue and the Berg balance scale, functional reach test, and the timed up-and-go test were also used as clinical evaluation indices. Repeated measures ANOVA was conducted to examine differences between before the exercises and at three and six weeks after beginning the exercises within each group, and the amounts of change between the two groups were compared. [Results] In the comparison within each group, both groups showed significant differences between before and after the experiment in all the tests and comparison between the groups showed that greater improvement was seen in all values in the FPS group. [Conclusion] In the present study, implementing FES and stretching exercises plus ankle joint muscle strengthening and proprioceptive exercises was more effective at improving stroke patients balance ability than implementing only FES and stretching exercises. PMID:26504337

  7. Young individuals with a more ankle-steered proprioceptive control strategy may develop mild non-specific low back pain.

    PubMed

    Claeys, Kurt; Dankaerts, Wim; Janssens, Lotte; Pijnenburg, Madelon; Goossens, Nina; Brumagne, Simon

    2015-04-01

    Altered proprioceptive postural control has been demonstrated in people with non-specific low back pain (LBP). However, the cause-effect relation remains unclear. Therefore, more prospective studies are necessary. Proprioceptive postural control of 104 subjects was evaluated at baseline using a force plate and with application of vibration stimulation on ankle and back muscles. Spinal postural angles were measured with digital photographs. Psychosocial variables and physical activity were registered using questionnaires. Ninety subjects were followed over two years concerning their LBP status, 14 were lost to follow-up. Four distinct groups were determined after two years based on pain and disability scores: never LBP, no LBP at intake with future mild LBP, mild LBP at intake with no further LBP, LBP at intake with further episodes of mild LBP. Risk factors for developing or sustaining LBP were calculated using logistic regression analysis. A more ankle-steered proprioceptive postural control strategy in upright standing increased the risk for developing or having recurrences of mild LBP within two years (Odds: 3.5; 95% CI: 1.1-10.8; p < 0.05). Increased postural sway, altered spinal postural angles, psychosocial and physical activity outcomes were not identified as risk factors for future mild LBP. These findings could contribute to improving the prevention and rehabilitation of LBP.

  8. The effects of ankle joint muscle strengthening and proprioceptive exercise programs accompanied by functional electrical stimulation on stroke patients' balance.

    PubMed

    Kim, Kyunghoon; Lee, Sukmin; Kim, Donghoon; Kim, Kyou Sik

    2015-09-01

    [Purpose] The purpose of the present study was to examine the effects of ankle joint muscle strengthening and proprioceptive exercises accompanied by functional electrical stimulation on stroke patients' balance ability. [Methods] For six weeks beginning in April 2015, 22 stroke patients receiving physical therapy at K Hospital located in Gyeonggi-do were divided into a functional electrical stimulation (FES), ankle proprioceptive exercise and ankle joint muscle strengthening exercise group (FPS group) of 11 patients and an FES and stretching exercise group (FS group) of 11 patients. The stimulation and exercises were conducted for 30 min per day, five days per week for six weeks. Balance ability was measured using a BioRescue and the Berg balance scale, functional reach test, and the timed up-and-go test were also used as clinical evaluation indices. Repeated measures ANOVA was conducted to examine differences between before the exercises and at three and six weeks after beginning the exercises within each group, and the amounts of change between the two groups were compared. [Results] In the comparison within each group, both groups showed significant differences between before and after the experiment in all the tests and comparison between the groups showed that greater improvement was seen in all values in the FPS group. [Conclusion] In the present study, implementing FES and stretching exercises plus ankle joint muscle strengthening and proprioceptive exercises was more effective at improving stroke patients balance ability than implementing only FES and stretching exercises.

  9. Low back skin sensitivity has minimal impact on active lumbar spine proprioception and stability in healthy adults.

    PubMed

    Beaudette, Shawn M; Larson, Katelyn J; Larson, Dennis J; Brown, Stephen H M

    2016-08-01

    The purpose of the current work was to (1) determine whether low back cutaneous sensitivity could be reduced through the use of a topical lidocaine-prilocaine anesthetic (EMLA(®)) to mirror reductions reported in chronic lower back pain (CLBP) patients, as well as to (2) identify whether reductions in cutaneous sensitivity resulted in decreased lumbar spine proprioception, neuromuscular control and dynamic stability. Twenty-eight healthy participants were divided equally into matched EMLA and PLACEBO treatment groups. Groups completed cutaneous minimum monofilament and two-point discrimination (TPD) threshold tests, as well as tests of sagittal and axial lumbar spine active repositioning error, seated balance and repeated lifting dynamic stability. These tests were administered both before and after the application of an EMLA or PLACEBO treatment. Results show that low back minimum monofilament and TPD thresholds were significantly increased within the EMLA group. Skin sensitivity remained unchanged in the PLACEBO group. In the EMLA group, decreases in low back cutaneous sensitivity had minimal effect on low back proprioception (active sagittal and axial repositioning) and dynamic stability (seated balance and repeated lifting). These findings demonstrate that treating the skin of the low back with an EMLA anesthetic can effectively decrease the cutaneous sensitivity of low back region. Further, these decreases in peripheral cutaneous sensitivity are similar in magnitude to those reported in CLBP patients. Within this healthy population, decreased cutaneous sensitivity of the low back region has minimal influence on active lumbar spine proprioception, neuromuscular control and dynamic stability.

  10. Shift in saccadic direction induced in humans by proprioceptive manipulation: a comparison between memory-guided and visually guided saccades.

    PubMed

    Allin, F; Velay, J L; Bouquerel, A

    1996-08-01

    It is nowadays generally recognized that saccades to remembered targets are planned in a craniotopic frame of reference by combining retinal input with eye position signal. The origin of the eye position signal is still a matter of controversy, however. Does it arise from an efferent copy or is it supplied by the sensory receptors with which the extraocular muscles are endowed? When applied to skeletal muscles, vibration elicits spindle responses simulating a stretching of the vibrated muscle. When vibration is applied to the inferior rectus muscle (IR), it induces the illusion that a stationary fixating point is moving upward. Here we attempted to change the initial eye position signal supplied to the oculomotor system before a memory- or visuo-guided saccade to a 10 degrees left target by applying mechanical vibration to the IR muscle. We wanted to determine whether modifying extraocular proprioceptive cues during the programming phase of a saccade might affect the latter's trajectory. In the memory-guided condition, it was observed that the saccades ended lower down when vibration was applied than in the control condition. Conversely, the visuo-guided saccades were not affected by the vibration. The above results mean first that extraocular proprioceptive cues are used as an initial eye position signal when a memory guided saccade has to be planned. Secondly, they suggest that extraocular proprioception may not be used to produce a visuo-guided saccade, or that this type of saccade is computed solely on the basis of retinal cues. PMID:8871106

  11. Are there any relationships among ankle proprioception acuity, pre-landing ankle muscle responses, and landing impact in man?

    PubMed

    Fu, Siu Ngor; Hui-Chan, Christina Wan Ying

    2007-05-01

    Proprioceptive input has been suggested to contribute to the pre-landing muscle responses associated with drop-landing, but its precise role has yet to be delineated. This study set out to examine the relationships among ankle proprioception, pre-landing muscle responses, and landing impact on drop-landing in healthy man. Fifteen healthy male basketball players aged 18 to 26 participated in this study. Passive ankle joint repositioning errors were used to examine ankle joint proprioception. Pre-landing EMG responses in the ankle muscles and the impact force on landing were recorded while the players performed self-initiated drops from a height of 30 cm. Results demonstrated that averaged ankle repositioning errors were significantly correlated with the co-contraction indexes between left tibialis anterior and medial gastrocnemius muscles (TA/MG CoI) (r=0.67, p=0.006), and showed a trend towards a relationship with the right TA/MG CoI (r=0.47, p=0.079). TA/MG CoI from both ankles were further related to the magnitude of the total impact force on landing (r=0.54 and 0.53, respectively; p<0.05). We concluded that male basketball players with less accurate ankle joint sense adopted greater co-contraction of ankle dorsiflexors and platarflexors, which was in turn associated with greater impact force at the moment of landing.

  12. Development of a Protocol to Test Proprioceptive Utilization as a Predictor for Sensorimotor Adaptability

    NASA Technical Reports Server (NTRS)

    Goel, R.; De Dios, Y. E.; Gadd, N. E.; Caldwell, E. E.; Peters, B. T.; Bloomberg, J. J.; Oddsson, L. I. E.; Mulavara, A. P.

    2016-01-01

    Astronauts returning from space flight show significant inter-subject variations in their abilities to readapt to a gravitational environment because of their innate sensory weighting. The ability to predict the manner and degree to which each individual astronaut will be affected would improve the effectiveness of countermeasure training programs designed to enhance sensorimotor adaptability. We hypothesize participant's ability to utilize individual sensory information (vision, proprioception and vestibular) influences adaptation in sensorimotor performance after space flight. The goal of this study is to develop a reliable protocol to test proprioceptive utilization in a functional postural control task. Subjects "stand" in a supine position while strapped to a backpack frame holding a friction-free device using air-bearings that allow the subject to move freely in the frontal plane, similar to when in upright standing. The frame is attached to a pneumatic cylinder, which can provide different levels of a gravity-like force that the subject must balance against to remain "upright". The supine posture with eyes closed ensures reduced vestibular and visual contribution to postural control suggesting somatosensory and/or non-otolith vestibular inputs will provide relevant information for maintaining balance control in this task. This setup is called the gravity bed. Fourteen healthy subjects carried out three trials each with eyes open alternated with eyes closed, "standing" on their dominant leg in the gravity bed environment while loaded with 60 percent of their body weight. Subjects were instructed to: "use your sense of sway about the ankle and pressure changes under the foot to maintain balance." Maximum length of a trial was 45 seconds. A force plate underneath the foot recorded forces and moments during the trial and an inertial measurement unit (IMU) attached on the backpack's frame near the center of mass of the subject recorded upper body postural

  13. Slow Lévy flights

    NASA Astrophysics Data System (ADS)

    Boyer, Denis; Pineda, Inti

    2016-02-01

    Among Markovian processes, the hallmark of Lévy flights is superdiffusion, or faster-than-Brownian dynamics. Here we show that Lévy laws, as well as Gaussian distributions, can also be the limit distributions of processes with long-range memory that exhibit very slow diffusion, logarithmic in time. These processes are path dependent and anomalous motion emerges from frequent relocations to already visited sites. We show how the central limit theorem is modified in this context, keeping the usual distinction between analytic and nonanalytic characteristic functions. A fluctuation-dissipation relation is also derived. Our results may have important applications in the study of animal and human displacements.

  14. Glut, war slow Mideast activity

    SciTech Connect

    Not Available

    1984-07-20

    Oilpatch activity in the Middle East has been on the slow side recently, and with a heated-up war between Iran and Iraq throwing off violent sparks around the Arabian Gulf, it's difficult to keep one's mind on business-as-usual. The article deals with the rising cost of insurance for shipping because of the war and the effects on drilling, production and the environment (oil spills). The development and production of offshore oil and gas in Egypt, Saudi Arabia, and the United Arab Emirates is also discussed.

  15. Intense source of slow positrons

    NASA Astrophysics Data System (ADS)

    Perez, P.; Rosowsky, A.

    2004-10-01

    We describe a novel design for an intense source of slow positrons based on pair production with a beam of electrons from a 10 MeV accelerator hitting a thin target at a low incidence angle. The positrons are collected with a set of coils adapted to the large production angle. The collection system is designed to inject the positrons into a Greaves-Surko trap (Phys. Rev. A 46 (1992) 5696). Such a source could be the basis for a series of experiments in fundamental and applied research and would also be a prototype source for industrial applications, which concern the field of defect characterization in the nanometer scale.

  16. The contribution of proprioceptive information to postural control in elderly and patients with Parkinson's disease with a history of falls.

    PubMed

    Bekkers, Esther M J; Dockx, Kim; Heremans, Elke; Vercruysse, Sarah; Verschueren, Sabine M P; Mirelman, Anat; Nieuwboer, Alice

    2014-01-01

    Proprioceptive deficits negatively affect postural control but their precise contribution to postural instability in Parkinson's disease (PD) is unclear. We investigated if proprioceptive manipulations differentially affect balance, measured by force plates, during quiet standing in 13 PD patients and 13 age-matched controls with a history of falls. Perceived limits of stability (LoS) were derived from the differences between maximal center of pressure (CoP) displacement in anterior-posterior (AP) and medio-lateral (ML) direction during a maximal leaning task. Task conditions comprised standing with eyes open (EO) and eyes closed (EC): (1) on a stable surface; (2) an unstable surface; and (3) with Achilles tendon vibration. CoP displacements were calculated as a percentage of their respective LoS. Perceived LoS did not differ between groups. PD patients showed greater ML CoP displacement than elderly fallers (EF) across all conditions (p = 0.043) and tended to have higher postural sway in relation to the LoS (p = 0.050). Both groups performed worse on an unstable surface and during tendon vibration compared to standing on a stable surface with EO and even more so with EC. Both PD and EF had more AP sway in all conditions with EC compared to EO (p < 0.001) and showed increased CoP displacements when relying on proprioception only compared to standing with normal sensory input. This implies a similar role of the proprioceptive system in postural control in fallers with and without PD. PD fallers showed higher ML sway after sensory manipulations, as a result of which these values approached their perceived LoS more closely than in EF. We conclude that despite a similar fall history, PD patients showed more ML instability than EF, irrespective of sensory manipulation, but had a similar reliance on ankle proprioception. Hence, we recommend that rehabilitation and fall prevention for PD should focus on motor rather than on sensory aspects.

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

    PubMed

    Brun, C; Guerraz, M

    2015-12-01

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

  18. Slow wave sleep in crayfish.

    PubMed

    Ramón, Fidel; Hernández-Falcón, Jesús; Nguyen, Bao; Bullock, Theodore H

    2004-08-10

    Clear evidence of sleep in invertebrates is still meager. Defined as a distinct state of reduced activity, arousability, attention, and initiative, it is well established in mammals, birds, reptiles, and teleosts. It is commonly defined by additional electroencephalographic criteria that are only well established in mammals and to some extent in birds. Sleep states similar to those in mammals, except for electrical criteria, seem to occur in some invertebrates, based on behavior and some physiological observations. Currently the most compelling evidence for sleep in invertebrates (evidence that meets most standard criteria for sleep) has been obtained in the fruit fly Drosophila melanogaster. However, in mammals, sleep is also characterized by a brain state different from that at rest but awake. The electrophysiological slow wave criterion for this state is not seen in Drosophila or in honey bees. Here, we show that, in crayfish, a behavioral state with elevated threshold for vibratory stimulation is accompanied by a distinctive form of slow wave electrical activity of the brain, quite different from that during waking rest. Therefore, crayfish can attain a sleep state comparable to that of mammals. PMID:15286285

  19. Double Chooz Slow Monitoring System

    NASA Astrophysics Data System (ADS)

    Chang, Pi-Jung; Horton-Smith, Glenn; McKee, David; Shrestha, Deepak; Winslow, Lindley; Conrad, Janet

    2010-02-01

    The Double Chooz experiment aims to measure neutrino flux from two nearly identical detectors with an uncertainty less than 0.6%. The Double Chooz slow monitoring system records conditions of the experiment's environment which can impact the experiment's goals. The slow monitoring system includes temperatures and voltages in electronics, experimental hall environmental conditions, line voltages, liquid temperatures, PMT's magnetic field, radon concentrations, and photo-tube high voltages. This system scans all channels automatically, stores data in a common database, and warns of changes in the two detectors' physical environments. Most functions in this system can be accomplished by 1-Wire products from Dallas Semiconductor. We can use a single master for several functions' controls and operations and the power is derived from a signal bus. Every device has a unique unalterable ID. The sensors monitoring the liquid system, such as liquid thermal meters, are covered by epoxy in order to isolate in the liquid. Their radioactivity can be ignored and will not affect the uncertainty in the system. )

  20. The effect of static, ballistic, and proprioceptive neuromuscular facilitation stretching on vertical jump performance.

    PubMed

    Bradley, Paul S; Olsen, Peter D; Portas, Matthew D

    2007-02-01

    The purpose of this study was to compare the acute effects of different modes of stretching on vertical jump performance. Eighteen male university students (age, 24.3 +/- 3.2 years; height, 181.5 +/- 11.4 cm; body mass, 78.1 +/- 6.4 kg; mean +/- SD) completed 4 different conditions in a randomized order, on different days, interspersed by a minimum of 72 hours of rest. Each session consisted of a standard 5-minute cycle warm-up, accompanied by one of the subsequent conditions: (a) control, (b) 10-minute static stretching, (c) 10-minute ballistic stretching, or (d) 10-minute proprioceptive neuromuscular facilitation (PNF) stretching. The subjects performed 3 trials of static and countermovement jumps prior to stretching and poststretching at 5, 15, 30, 45, and 60 minutes. Vertical jump height decreased after static and PNF stretching (4.0% and 5.1%, p < 0.05) and there was a smaller decrease after ballistic stretching (2.7%, p > 0.05). However, jumping performance had fully recovered 15 minutes after all stretching conditions. In conclusion, vertical jump performance is diminished for 15 minutes if performed after static or PNF stretching, whereas ballistic stretching has little effect on jumping performance. Consequently, PNF or static stretching should not be performed immediately prior to an explosive athletic movement.

  1. Proprioceptive neuropathy affects normalization of the H-reflex by exercise after spinal cord injury

    PubMed Central

    Ollivier-Lanvin, Karen; Keeler, Benjamin E.; Siegfried, Rachel; Houlé, John D.; Lemay, Michel A.

    2009-01-01

    The H-reflex habituates at relatively low frequency (10 Hz) stimulation in the intact spinal cord, but loss of descending inhibition resulting from spinal cord transection reduces this habituation. There is a return towards a normal pattern of low-frequency habituation in the reflex activity with cycling exercise of the affected hind limbs. This implies that repetitive passive stretching of the muscles in spinalized animals and the accompanying stimulation of large (Group I and II) proprioceptive fibers has modulatory effects on spinal cord reflexes after injury. To test this hypothesis, we induced pyridoxine neurotoxicity that preferentially affects large dorsal root ganglia neurons in intact and spinalized rats. Pyridoxine or saline injections were given twice daily (IP) for 6 weeks and half of the spinalized animals were subjected to cycling exercise during that period. After 6 weeks, the tibial nerve was stimulated electrically and recordings of M and H waves were made from interosseous muscles of the hind paw. Results show that pyridoxine treatment completely eliminated the H-reflex in spinal intact animals. In contrast, transection paired with pyridoxine treatment resulted in a reduction of the frequency-dependent habituation of the H-reflex that was not affected by exercise. These results indicate that normal Group I and II afferent input is critical to achieve exercise-based reversal of hyper-reflexia of the H-reflex after spinal cord injury. PMID:19913536

  2. The Change in Fingertip Contact Area as a Novel Proprioceptive Cue

    PubMed Central

    Moscatelli, Alessandro; Bianchi, Matteo; Serio, Alessandro; Terekhov, Alexander; Hayward, Vincent; Ernst, Marc O.; Bicchi, Antonio

    2016-01-01

    Summary Humans, many animals, and certain robotic hands have deformable fingertip pads [1, 2]. Deformable pads have the advantage of conforming to the objects that are being touched, ensuring a stable grasp for a large range of forces and shapes. Pad deformations change with finger displacements during touch. Pushing a finger against an external surface typically provokes an increase of the gross contact area [3], potentially providing a relative motion cue, a situation comparable to looming in vision [4]. The rate of increase of the area of contact also depends on the compliance of the object [5]. Because objects normally do not suddenly change compliance, participants may interpret an artificially induced variation in compliance, which coincides with a change in the gross contact area, as a change in finger displacement, and consequently they may misestimate their finger’s position relative to the touched object. To test this, we asked participants to compare the perceived displacements of their finger while contacting an object varying pseudo-randomly in compliance from trial to trial. Results indicate a bias in the perception of finger displacement induced by the change in compliance, hence in contact area, indicating that participants interpreted the altered cutaneous input as a cue to proprioception. This situation highlights the capacity of the brain to take advantage of knowledge of the mechanical properties of the body and of the external environment. PMID:27068417

  3. Peculiarities of human psychoneuroendocrinology within support deprivation and decreased proprioceptive afferentation

    NASA Astrophysics Data System (ADS)

    Nichiporuk, Igor

    Essentially important circumstance which is necessary for considering in a complex estimation of physical and mental health of the person in the conditions of space flight are interrelation and interference between neurohormoral system and the psychophysiological status. A main objective of research was a study of relationships of psychoneuroendocrine parameters of the person during simulation of microgravity effects via 7-day dry immersion (DI) in healthy male-volunteers 20-35 years old. The individual and typological features, which reflect specificity of behavior and the higher nervous activity in DI, have been revealed as a result of complex checkup consisting of thrice-repeated identical hormonal and psychophysiological measurements (initial, within and recovery). It allowed to define the system of the dominants determining an efficiency of personal activity in the conditions of support deprivation and decreased proprioceptive afferentation (DI’s effects), and also to reveal independent indicators of psychoneuroendocrine state, which define high capacity for work, in particular, properties of temperament, levels of stress, social conformity and emotional maturity, a sharing involvement of simple and complex sensory-motor reactions, balance and activity of thyroid, vago-insular and glucocorticoid systems of human organism.

  4. The Effects of Taping Prior to PNF Treatment on Lower Extremity Proprioception of Hemiplegic Patients

    PubMed Central

    Choi, Yong-Kyu; Nam, Chan-Woo; Lee, Jung-Ho; Park, Young-Han

    2013-01-01

    [Purpose] The purpose of this study was to compare the effects of taping on the articular angle of the knee joint and on the functioning of patients with hemiplegia resulting from stroke. [Subjects] The subjects of this study were 30 patients who were diagnosed with hemiplegia due to stroke. The subjects were randomly assigned to either an experimental group which received proprioceptive neuromuscular facilitation combination patterns and kinesio taping were applied, or a control group which received neurodevelopmental treatment. [Methods] Joint angle was measured at the hip and the ankle for both the paretic and non-paretic sides using a goniometer. Dynamic balance ability was assessed using the Berg Balance Scale. Gait velocity was measured as the 10-m walking time using a stopwatch. [Results] Comparative analysis of the experimental group's pre-test and post-test results showed statistically significant differences in the BBS and 10-m walking test. There were significant differences between the groups in ankle dorsiflexion, BBS, and 10-m walking times. [Conclusion] We judge the application of taping on the knee joint prior to rehabilitation treatment for patients in accordance with nervous system damage positively influences their functional improvement. PMID:24259927

  5. Slow magnetohydrodynamic waves in the solar atmosphere.

    PubMed

    Roberts, B

    2006-02-15

    There is increasingly strong observational evidence that slow magnetoacoustic modes arise in the solar atmosphere, either as propagating or standing waves. Sunspots, coronal plumes and coronal loops all appear to support slow modes. Here we examine theoretically how the slow mode may be extracted from the magnetohydrodynamic equations, considering the special case of a vertical magnetic field in a stratified medium: the slow mode is described by the Klein-Gordon equation. We consider its application to recent observations of slow waves in coronal loops. PMID:16414890

  6. Highly Alfvenic Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Roberts, D. Aaron

    2010-01-01

    It is commonly thought that fast solar wind tends to be highly Alfvenic, with strong correlations between velocity and magnetic fluctuations, but examples have been known for over 20 years in which slow wind is both Alfvenic and has many other properties more typically expected of fast solar wind. This paper will present a search for examples of such flows from more recent data, and will begin to characterize the general characteristics of them. A very preliminary search suggests that such intervals are more common in the rising phase of the solar cycle. These intervals are important for providing constraints on models of solar wind acceleration, and in particular the role waves might or might not play in that process.

  7. Plant domestication slows pest evolution.

    PubMed

    Turcotte, Martin M; Lochab, Amaneet K; Turley, Nash E; Johnson, Marc T J

    2015-09-01

    Agricultural practices such as breeding resistant varieties and pesticide use can cause rapid evolution of pest species, but it remains unknown how plant domestication itself impacts pest contemporary evolution. Using experimental evolution on a comparative phylogenetic scale, we compared the evolutionary dynamics of a globally important economic pest - the green peach aphid (Myzus persicae) - growing on 34 plant taxa, represented by 17 crop species and their wild relatives. Domestication slowed aphid evolution by 13.5%, maintained 10.4% greater aphid genotypic diversity and 5.6% higher genotypic richness. The direction of evolution (i.e. which genotypes increased in frequency) differed among independent domestication events but was correlated with specific plant traits. Individual-based simulation models suggested that domestication affects aphid evolution directly by reducing the strength of selection and indirectly by increasing aphid density and thus weakening genetic drift. Our results suggest that phenotypic changes during domestication can alter pest evolutionary dynamics.

  8. Is cosmic acceleration slowing down?

    SciTech Connect

    Shafieloo, Arman; Sahni, Varun; Starobinsky, Alexei A.

    2009-11-15

    We investigate the course of cosmic expansion in its recent past using the Constitution SN Ia sample, along with baryon acoustic oscillations (BAO) and cosmic microwave background (CMB) data. Allowing the equation of state of dark energy (DE) to vary, we find that a coasting model of the universe (q{sub 0}=0) fits the data about as well as Lambda cold dark matter. This effect, which is most clearly seen using the recently introduced Om diagnostic, corresponds to an increase of Om and q at redshifts z < or approx. 0.3. This suggests that cosmic acceleration may have already peaked and that we are currently witnessing its slowing down. The case for evolving DE strengthens if a subsample of the Constitution set consisting of SNLS+ESSENCE+CfA SN Ia data is analyzed in combination with BAO+CMB data. The effect we observe could correspond to DE decaying into dark matter (or something else)

  9. Effects of proprioceptive neuromuscular facilitation neck pattern exercise on the ability to control the trunk and maintain balance in chronic stroke patients.

    PubMed

    Hwangbo, Pil Neo; Don Kim, Kyoung

    2016-03-01

    [Purpose] The aim of this study was to investigate the effects of proprioceptive neuromuscular facilitation neck pattern exercise on the ability to control the trunk and balance in chronic stroke patients. [Subjects and Methods] A total of 30 study subjects were selected and randomly divided into an experimental group of 15 subjects, who received the proprioceptive neuromuscular facilitation neck pattern exercise, and a control group of 15 subjects, who received a traditional rehabilitation treatment. [Results] Statistically significant changes in all the items of the Trunk Impairment Scale, the Trunk Impairment Scale total score, and the Berg Balance Scale were observed in both the experimental group and the control group. significant between-group differences were found in all items among the subitems of the Trunk Impairment Scale except the static sitting balance. [Conclusion] Proprioceptive neuromuscular facilitation neck pattern exercise was shown to have a positive effect on increasing the ability to control the trunk and maintain balance in chronic stroke patients.

  10. Short-term Effects of a Proprioceptive Training Session with Unstable Platforms on the Monopodal Stabilometry of Athletes

    PubMed Central

    Romero-Franco, Natalia; Martínez-Amat, Antonio; Hita-Contreras, Fidel; Martínez-López, Emilio J

    2014-01-01

    To analyze the short-term effects of a proprioceptive session on the monopodal stabilometry of athletes. [Subjects] Thirty-seven athletes were divided into a control group (n=17) and an experimental group (n=20). [Methods] Both groups performed a conventional warm-up, after which a 25-minute proprioceptive session on ustable platforms was carried out only by the experimental group. Before the training session, all athletes carried out a single-leg stabilometry test which was repeated just after training, 30 minutes, 1 hour, 6 hours and 24 hours later. [Results] Analysis of covariance (α=0.05) revealed that the experimental group had lower values than the control group in length and velocity of center of pressure (CoP) of left-monopodal stance and in velocity of CoP of right-monopodal stance in post-training measurements. Also, the experimental group had values closer to zero for the CoP position in the mediolateral and anteroposterior directions of left-monopodal stance (Xmeanl and Ymeanl) and the anteroposterior direction in on right-monopodal stance (Ymeanr) in post-training measurements. Within-group analysis of Xmeanl and Ymeanl, length and velocity of CoP in right-monopodal stance showed continuous fluctuations of values between sequential measurements in the control group. [Conclusion] Proprioceptive training on unstable platfoms after a warm-up stabilizes the position of CoP in the anteroposterior and mediolateral directions and decreases CoP movements in short-term monopodal stability of athletes. PMID:24567674

  11. Reach and Grasp reconfigurations reveal that proprioception assists reaching and hapsis assists grasping in peripheral vision.

    PubMed

    Hall, Lauren A; Karl, Jenni M; Thomas, Brittany L; Whishaw, Ian Q

    2014-09-01

    The dual visuomotor channel theory proposes that prehension consists of a Reach that transports the hand in relation to an object's extrinsic properties (e.g., location) and a Grasp that shapes the hand to an object's intrinsic properties (e.g., size and shape). In central vision, the Reach and the Grasp are integrated but when an object cannot be seen, the movements can decompose with the Reach first used to locate the object and the Grasp postponed until it is assisted by touch. Reaching for an object in a peripheral visual field is an everyday act, and although it is reported that there are changes in Grasp aperture with target eccentricity, it is not known whether the configuration of the Reach and the Grasp also changes. The present study examined this question by asking participants to reach for food items at 0° or 22.5° and 45° from central gaze. Participants made 15 reaches for a larger round donut ball and a smaller blueberry, and hand movements were analyzed using frame-by-frame video inspection and linear kinematics. Perception of targets was degraded as participants could not identify objects in peripheral vision but did recognize their differential size. The Reach to peripheral targets featured a more dorsal trajectory, a more open hand, and less accurate digit placement. The Grasp featured hand adjustments or target manipulations after contact, which were associated with a prolonged Grasp duration. Thus, Grasps to peripheral vision did not consist only of a simple modification of visually guided reaching but included the addition of somatosensory assistance. The kinematic and behavioral changes argue that proprioception assists the Reach and touch assists the Grasp in peripheral vision, supporting the idea that Reach and Grasp movements are used flexibly in relation to sensory guidance depending upon the salience of target properties.

  12. A physical control interface with proprioceptive feedback and multiple degrees of freedom

    NASA Technical Reports Server (NTRS)

    Creasey, G. H.; Gow, D.; Sloan, Y.; Meadows, B.

    1991-01-01

    The use of the drug thalidomide by pregnant mothers in Britain resulted in a variety of deformities including the birth of children having no arms. Such children were provided with powered artificial arms with up to five degrees of freedom simultaneously controlled in real time by shoulder movement. The physiological sense of proprioception was extended from the user into the device, reducing the need for visual feedback and conscious control. With the banning of thalidomide, this technique fell into disuse but it is now being re-examined as a control mechanism for other artificial limbs and it may have other medical applications to allow patients to control formerly paralyzed limbs moved by electrical stimulation. It may also have commercial applications in robotic manipulation or physical interaction with virtual environments. To allow it to be investigated further, the original pneumatic control system has recently been converted to an electrical analogue to allow interfacing to electronic and computer-assisted systems. A harness incorporates force-sensitive resistors and linear potentiomenters for sensing position and force at the interface with the skin, and miniature electric motors and lead screws for feeding back to the user the position of the robotic arm and the forces applied to it. In the present system, control is applied to four degrees of freedom using elevation/depression and protraction/reaction of each shoulder so that each collar bone emulates a joystick. However, both electrical and mechanical components have been built in modular form to allow rapid replication and testing of a variety of force and position control strategies.

  13. Comparing limb proprioception and oculomotor signals during hand-guided saccades.

    PubMed

    Ren, L; Blohm, G; Crawford, J D

    2007-09-01

    We previously showed that saccades tend to overshoot briefly flashed targets that were manually displaced in the dark (Ren et al. 2006). However it was not clear if the overshoot originated from a sensory error in measuring hand displacement or from a premotor error in saccade programming, because gaze and hand position started at the same central position. Here, we tested between these hypotheses by dissociating the initial eye and hand position. Five hand/target positions (center, far, near, right, left) on a frontally-placed horizontal surface were used in four paradigms: Center or Peripheral Eye-hand Association (CA or PA, both gaze and right hand started from the center or a same peripheral location) and Hand or Eye Dissociation (HD or ED, hand or gaze started from one of three non-target peripheral locations). Subjects never received any visual feedback about the final target location and the subjects' hand displacement. In the CA paradigm, subjects showed the same overshoot that we showed previously. However, changing both initial eye and hand positions relative to the final target (PA) affected the pattern, significantly altering the directions of overshoots. Changing only the initial position of hand (HD) did not have this effect, whereas changing only initial eye position (ED) had the same effect as the PA condition (CA approximately HD, PA approximately ED). Furthermore, multiple regression analysis showed that the direction of the ideal saccade contributed significantly to the endpoint direction error, not the direction of the hand path. These results suggest that these errors do not primarily arise from misestimates of the hand trajectory, but rather from a process of comparing the initial eye position and the limb proprioceptive signal during saccade programming.

  14. Neuromodulation of Limb Proprioceptive Afferents Decreases Apnea of Prematurity and Accompanying Intermittent Hypoxia and Bradycardia

    PubMed Central

    Kesavan, Kalpashri; Frank, Paul; Cordero, Daniella M.; Benharash, Peyman; Harper, Ronald M.

    2016-01-01

    Background Apnea of Prematurity (AOP) is common, affecting the majority of infants born at <34 weeks gestational age. Apnea and periodic breathing are accompanied by intermittent hypoxia (IH). Animal and human studies demonstrate that IH exposure contributes to multiple pathologies, including retinopathy of prematurity (ROP), injury to sympathetic ganglia regulating cardiovascular action, impaired pancreatic islet cell and bone development, cerebellar injury, and neurodevelopmental disabilities. Current standard of care for AOP/IH includes prone positioning, positive pressure ventilation, and methylxanthine therapy; these interventions are inadequate, and not optimal for early development. Objective The objective is to support breathing in premature infants by using a simple, non-invasive vibratory device placed over limb proprioceptor fibers, an intervention using the principle that limb movements trigger reflexive facilitation of breathing. Methods Premature infants (23–34 wks gestational age), with clinical evidence of AOP/IH episodes were enrolled 1 week after birth. Caffeine treatment was not a reason for exclusion. Small vibration devices were placed on one hand and one foot and activated in 6 hour ON/OFF sequences for a total of 24 hours. Heart rate, respiratory rate, oxygen saturation (SpO2), and breathing pauses were continuously collected. Results Fewer respiratory pauses occurred during vibration periods, relative to baseline (p<0.005). Significantly fewer SpO2 declines occurred with vibration (p<0.05), relative to control periods. Significantly fewer bradycardic events occurred during vibration periods, relative to no vibration periods (p<0.05). Conclusions In premature neonates, limb proprioceptive stimulation, simulating limb movement, reduces breathing pauses and IH episodes, and lowers the number of bradycardic events that accompany aberrant breathing episodes. This low-cost neuromodulatory procedure has the potential to provide a non

  15. [Proprioceptive deficit following cruciate lesions--afferent disorder or compensatory mechanism?].

    PubMed

    Hopf, T; Gleitz, M; Hess, T; Mielke, U; Müller, B

    1995-01-01

    It was suggested that the ACL has not only mechanical functions but also acts as proprioceptive organ. In cruciate deficient knees pathological patterns of muscle control were found. These findings could be caused by a disturbed afferent signal from the disrupted ACL or by secondary changes in muscle innervation, which shall protect the instable knee against subluxation. 33 patients with unilateral operative ACL repair (21 cases with primary suture, 12 cases with autogenous ligamentum-patellae-reconstruction; average post op 36.5 yr) were examined clinically and with the KT 1000 arthrometer (MEDMETRIC Inc.). Patients history was evaluated by using the LYSHOLM score. During a cycling task the electromyographic activity was monitored from the thigh muscles (M. vastus lat. and med., lat. and med. hamstrings). In comparison to the ACL deficient patients, we tested 25 healthy subjects of same age and activity level. In the ACL group the following differences to the normals were found: the M. vastus lat. showed a significantly delayed onset, earlier end and shorter duration. M. vastus med. had the same pattern; the delayed begin of activity and the shorter duration were statistically significant. M. biceps femoris showed a significant later onset and shorter duration. So did the medial hamstrings; the differences, however, were not statistically significant. There was no significant difference between operated and healthy leg in the ACL group. By comparing the primary sutures and the ligamentum-patellae-reconstructions no significant differences were found. The instable patients (KT 1000 > 3 mm) of the ACL group showed more distinct differences in the EMG pattern than the patients with stable knee joints.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. The effects of stair gait training using proprioceptive neuromuscular facilitation on stroke patients’ dynamic balance ability

    PubMed Central

    Seo, KyoChul; Park, Seung Hwan; Park, KwangYong

    2015-01-01

    [Purpose] This study aims to examine stroke patients’ changes in dynamic balance ability through stair gait training where in proprioceptive neuromuscular facilitation (PNF) was applied. [Subjects and Methods] In total 30 stroke patients participated in this experiment and were randomly and equally allocated to an experimental group and a control group. The experimental group received exercise treatment for 30 min and stair gait training where in PNF was applied for 30 min and the control group received exercise treatment for 30 min and ground gait training where in PNF was applied for 30 min. For the four weeks of the experiment, each group received training three times per week, for 30 min each time. Berg Balance Scale (BBS) values were measured and a time up and go (TUG) test and a functional reach test (FRT) were performed for a comparison before and after the experiment. [Results] According to the result of the stroke patients’ balance performance through stair gait training, the BBS and FRT results significantly increased and the TUG test result significantly decreased in the experimental group. On the contrary, BBS and FRT results did not significantly increase and the TUG test result did not significantly decrease in the control group. According to the result of comparing differences between before and after training in each group, there was a significant change in the BBS result of the experimental group only. [Conclusions] In conclusion, the gait training group to which PNF was applied saw improvements in their balance ability, and a good result is expected when neurological disease patients receive stair gait training applying PNF. PMID:26157240

  17. Slow myosin in developing rat skeletal muscle

    PubMed Central

    1987-01-01

    Through S1 nuclease mapping using a specific cDNA probe, we demonstrate that the slow myosin heavy-chain (MHC) gene, characteristic of adult soleus, is expressed in bulk hind limb muscle obtained from the 18-d rat fetus. We support these results by use of a monoclonal antibody (mAb) which is highly specific to the adult slow MHC. Immunoblots of MHC peptide maps show the same peptides, uniquely recognized by this antibody in adult soleus, are also identified in 18-d fetal limb muscle. Thus synthesis of slow myosin is an early event in skeletal myogenesis and is expressed concurrently with embryonic myosin. By immunofluorescence we demonstrate that in the 16-d fetus all primary myotubes in future fast and future slow muscles homogeneously express slow as well as embryonic myosin. Fiber heterogeneity arises owing to a developmentally regulated inhibition of slow MHC accumulation as muscles are progressively assembled from successive orders of cells. Assembly involves addition of new, superficial areas of the anterior tibial muscle (AT) and extensor digitorum longus muscle (EDL) in which primary cells initially stain weakly or are unstained with the slow mAb. In the developing AT and EDL, expression of slow myosin is unstable and is progressively restricted as these muscles specialize more and more towards the fast phenotype. Slow fibers persisting in deep portions of the adult EDL and AT are interpreted as vestiges of the original muscle primordium. A comparable inhibition of slow MHC accumulation occurs in the developing soleus but involves secondary, not primary, cells. Our results show that the fate of secondary cells is flexible and is spatially determined. By RIA we show that the relative proportions of slow MHC are fivefold greater in the soleus than in the EDL or AT at birth. After neonatal denervation, concentrations of slow MHC in the soleus rapidly decline, and we hypothesize that, in this muscle, the nerve protects and amplifies initial programs of slow MHC

  18. Head stabilization on a continuously oscillating platform: the effect of a proprioceptive disturbance on the balancing strategy.

    PubMed

    De Nunzio, Alessandro M; Nardone, Antonio; Schieppati, Marco

    2005-08-01

    When standing and balancing on a continuously and predictably moving platform, body equilibrium relies on both anticipatory control and proprioceptive feedback. We have vibrated different postural muscles of the body to assess any effect of confounding the proprioceptive input on balance during such unstable conditions. Low and high platform oscillation frequencies were used, because different strategies are used to withstand the two perturbations. Eyes open (EO) and closed (EC) conditions were also tested, to assess whether the stabilizing effect of vision is independent from the proprioceptive disturbance. Subjects (n = 14) performed two series of trials, EO and EC: (1) quiet erect stance, (2) stance on the platform translating at 0.2 or 0.6 Hz sinusoidally in the anteroposterior (A-P) direction (dynamic conditions). Continuous bilateral vibration (90 Hz) was produced by two vibrators fixed to the following homonymous muscles: dorsal neck, quadriceps, biceps femoris, tibialis anterior, and triceps surae. Acquisition of body segments' displacement began 10 s after the start of platform translation. From markers fixed to head, hip, and malleolus, we computed the A-P oscillation of head and hip, body orientation in space, and cross-correlation (CC) and time-delay between malleolus and head trajectories. The results were (a) the head A-P oscillation was smaller with EO than EC, under both quiet stance and dynamic conditions; (b) vibration of tibialis and triceps surae, but not of other muscles, slightly increased head and body A-P oscillation with EC under dynamic conditions; (c) at 0.2 Hz but not at 0.6 Hz, for all visual and vibration conditions, there was a significant association between head and feet; (d) at 0.2 Hz, EC, neck muscle vibration increased this association, whereas vibration of the other muscles induced a major time delay in the oscillation of head compared with feet; (e) vibration of either neck or tibialis induced forward body leaning, while

  19. Static postural sway, proprioception, and maximal voluntary quadriceps contraction in patients with knee osteoarthritis and normal control subjects

    PubMed Central

    Hassan, B; Mockett, S; Doherty, M

    2001-01-01

    OBJECTIVES—To investigate whether subjects with knee osteoarthritis (OA) have reduced static postural control, knee proprioceptive acuity, and maximal voluntary contraction (MVC) of the quadriceps compared with normal controls, and to determine possible independent predictors of static postural sway.
METHODS—77 subjects with symptomatic and radiographic knee OA (58 women, 19 men; mean age 63.4 years, range 36-82) and 63 controls with asymptomatic and clinically normal knees (45 women, 18 men; mean age 63 years, range 46-85) underwent assessment of static postural sway. 108 subjects (59 patients, 49 controls) also underwent assessment of knee proprioceptive activity and MVC (including calculation of quadriceps activation). In patients with knee OA knee pain, stiffness, and functional disability were assessed using the WOMAC Index. The height (m) and weight (kg) of all subjects was assessed.
RESULTS—Compared with controls, patients with knee OA were heavier (mean difference 15.3 kg, p<0.001), had increased postural lateral sway (controls: median 2.3, interquartile (IQ) range 1.8-2.9; patients: median 4.7, IQ range 1.9-4.7, p<0.001), reduced proprioceptive acuity (controls: mean 7.9, 95% CI 6.9 to 8.9; patients: mean 12.0, 95% CI 10.5 to 13.6, p<0.001), weaker quadriceps strength (controls: mean 22.5, 95% CI 19.9 to 24.6; patients: mean 14.7, 95% CI 12.5 to 16.9, p<0.001), and less percentage activation of quadriceps (controls: mean 87.4, 95% CI 80.7 to 94.2; patients: mean 66.0, 95% CI 58.8 to 73.2, p<0.001). The significant predictors of postural sway were knee pain and the ratio of MVC/body weight.
CONCLUSIONS—Compared with age and sex matched controls, subjects with symptomatic knee OA have quadriceps weakness, reduced knee proprioception, and increased postural sway. Pain and muscle strength may particularly influence postural sway. The interaction between physiological, structural, and functional abnormalities in knee OA

  20. The Effects of Comprehensive Warm-Up Programs on Proprioception, Static and Dynamic Balance on Male Soccer Players

    PubMed Central

    Daneshjoo, Abdolhamid; Mokhtar, Abdul Halim; Rahnama, Nader; Yusof, Ashril

    2012-01-01

    Purpose The study investigated the effects of FIFA 11+ and HarmoKnee, both being popular warm-up programs, on proprioception, and on the static and dynamic balance of professional male soccer players. Methods Under 21 year-old soccer players (n = 36) were divided randomly into 11+, HarmoKnee and control groups. The programs were performed for 2 months (24 sessions). Proprioception was measured bilaterally at 30°, 45° and 60° knee flexion using the Biodex Isokinetic Dynamometer. Static and dynamic balances were evaluated using the stork stand test and Star Excursion Balance Test (SEBT), respectively. Results The proprioception error of dominant leg significantly decreased from pre- to post-test by 2.8% and 1.7% in the 11+ group at 45° and 60° knee flexion, compared to 3% and 2.1% in the HarmoKnee group. The largest joint positioning error was in the non-dominant leg at 30° knee flexion (mean error value = 5.047), (p<0.05). The static balance with the eyes opened increased in the 11+ by 10.9% and in the HarmoKnee by 6.1% (p<0.05). The static balance with eyes closed significantly increased in the 11+ by 12.4% and in the HarmoKnee by 17.6%. The results indicated that static balance was significantly higher in eyes opened compared to eyes closed (p = 0.000). Significant improvements in SEBT in the 11+ (12.4%) and HarmoKnee (17.6%) groups were also found. Conclusion Both the 11+ and HarmoKnee programs were proven to be useful warm-up protocols in improving proprioception at 45° and 60° knee flexion as well as static and dynamic balance in professional male soccer players. Data from this research may be helpful in encouraging coaches or trainers to implement the two warm-up programs in their soccer teams. PMID:23251579

  1. AGS slow extracted beam improvement

    SciTech Connect

    Marneris, I.; Danowski, G.; Sandberg, J.; Soukas, A.

    1997-07-01

    The Brookhaven AGS is a strong focusing accelerator which is used to accelerate protons and various heavy ion species to an equivalent proton energy of 29 GeV. Since the late 1960`s it has been serving high energy physics (HEP - proton beam) users of both slow and fast extracted beams. The AGS fixed target program presently uses primary proton and heavy ion beams (HIP) in slowly extracted fashion over spill lengths of 1.5 to 4.0 seconds. Extraction is accomplished by flattoping the main and extraction magnets and exciting a third integer resonance in the AGS. Over the long spill times, control of the subharmonic amplitude components up to a frequency of 1 kilohertz is very crucial. One of the most critical contributions to spill modulation is due to the AGS MMPS. An active filter was developed to reduce these frequencies and it`s operation is described in a previous paper. However there are still frequency components in the 60-720 Hz sub-harmonic ripple range, modulating the spill structure due to extraction power supplies and any remaining structures on the AGS MMPS. A recent scheme is being developed to use the existing tune-trim control horizontal quadrupole magnets and power supply to further reduce these troublesome noise sources. Feedback from an external beam sensor and overcoming the limitations of the quadrupole system by lead/lag compensation techniques will be described.

  2. Slow-pitch softball injuries.

    PubMed

    Wheeler, B R

    1984-01-01

    A prospective investigation of slow-pitch softball injuries incurred in Hawaii was undertaken to study the nature of these injuries and analyze their causes. The injured players were involved in league softball with referees. There were 83 athletes and 93 injuries. A retrospective review of all Army softball-related admissions was also done. Thirty-five athletes or 42% were injured while sliding, 29 "foot first" and the remainder "hand first". Twenty-five of 27 ankle injuries caused by sliding included 20 fractures, 3 sprains, and 2 complete closed posterior dislocations. Analysis of these injuries suggests that the injury occurs when the individual uses the base to rapidly decelerate and avoid overrunning the base. Eighty-four percent of the athletes were injured from three mechanisms; 42% from sliding, 25% from "jamming" injuries, and 17% from falls. The only preventable group of injuries appears to be the sliding injuries. Recessing the bases, using "quick release" rather than anchored bases, teaching safer sliding techniques, or eliminating the slide are suggested as means of preventing these injuries.

  3. Phantom hand and wrist movements in upper limb amputees are slow but naturally controlled movements.

    PubMed

    De Graaf, J B; Jarrassé, N; Nicol, C; Touillet, A; Coyle, T; Maynard, L; Martinet, N; Paysant, J

    2016-01-15

    After limb amputation, patients often wake up with a vivid perception of the presence of the missing limb, called "phantom limb". Phantom limbs have mostly been studied with respect to pain sensation. But patients can experience many other phantom sensations, including voluntary movements. The goal of the present study was to quantify phantom movement kinematics and relate these to intact limb kinematics and to the time elapsed since amputation. Six upper arm and two forearm amputees with various delays since amputation (6months to 32years) performed phantom finger, hand and wrist movements at self-chosen comfortable velocities. The kinematics of the phantom movements was indirectly obtained via the intact limb that synchronously mimicked the phantom limb movements, using a Cyberglove® for measuring finger movements and an inertial measurement unit for wrist movements. Results show that the execution of phantom movements is perceived as "natural" but effortful. The types of phantom movements that can be performed are variable between the patients but they could all perform thumb flexion/extension and global hand opening/closure. Finger extension movements appeared to be 24% faster than finger flexion movements. Neither the number of types of phantom movements that can be executed nor the kinematic characteristics were related to the elapsed time since amputation, highlighting the persistence of post-amputation neural adaptation. We hypothesize that the perceived slowness of phantom movements is related to altered proprioceptive feedback that cannot be recalibrated by lack of visual feedback during phantom movement execution.

  4. Excitation of a slow wave structure

    SciTech Connect

    Zhang Peng; Lau, Y. Y.; Hoff, Brad; French, D. M.; Luginsland, J. W.

    2012-12-15

    The Green's function on a slow wave structure is constructed. The Green's function includes all radial modes, and for each radial mode, all space harmonics. We compare the analytic solution of the frequency response on the slow wave structure with that obtained from a particle-in-cell code. Favorable comparison is obtained when the first few lower order modes are resonantly excited. This gives some confidence in the prediction of converting a pulse train into radiation using a slow wave structure.

  5. Evaluation of effects of different treatments for the wrist joints of subdominant hands using joint proprioception and writing time

    PubMed Central

    Hu, Chunying; Huang, Qiuchen; Yu, Lili; Hu, Yue; Rongming, Xia; Li, Zhou; Xiaojiao, Fu; Gu, Rui; Cui, Yao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

    2016-01-01

    [Purpose] The purpose of this study was to examine immediate effects of strength training and NJF distal resistance training in wrist joints by using writing time and evaluation of proprioception using the JPE test. [Subjects and Methods] The subjects were 12 young healthy people (24.2 ± 3.1 y, 169.7 ± 6.5 cm, 65.3 ± 12.6 kg). Two isotonic contraction techniques were applied on the wrist joint: wrist joint extension muscle strength training (MST) and the wrist joint extension pattern of NJF. The uppercase English alphabet writing time and joint position errors of the left upper limb were measured before and after one intervention session of MST and NJF. [Results] The decrease in errors in wrist extension angle repetition and the writing time represented the improvement resulting from NJF. [Conclusion] This result suggests that the subdominant hands wrist joint proprioception and writing function can be improved by NJF together with proximal resistance training. PMID:27313380

  6. Evaluation of effects of different treatments for the wrist joints of subdominant hands using joint proprioception and writing time.

    PubMed

    Hu, Chunying; Huang, Qiuchen; Yu, Lili; Hu, Yue; Rongming, Xia; Li, Zhou; Xiaojiao, Fu; Gu, Rui; Cui, Yao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

    2016-05-01

    [Purpose] The purpose of this study was to examine immediate effects of strength training and NJF distal resistance training in wrist joints by using writing time and evaluation of proprioception using the JPE test. [Subjects and Methods] The subjects were 12 young healthy people (24.2 ± 3.1 y, 169.7 ± 6.5 cm, 65.3 ± 12.6 kg). Two isotonic contraction techniques were applied on the wrist joint: wrist joint extension muscle strength training (MST) and the wrist joint extension pattern of NJF. The uppercase English alphabet writing time and joint position errors of the left upper limb were measured before and after one intervention session of MST and NJF. [Results] The decrease in errors in wrist extension angle repetition and the writing time represented the improvement resulting from NJF. [Conclusion] This result suggests that the subdominant hands wrist joint proprioception and writing function can be improved by NJF together with proximal resistance training.

  7. Tactile and proprioceptive sensory stimulation modifies estimation of walking distance but not upright gait stability: a pilot study

    PubMed Central

    Paolucci, Teresa; Piccinini, Giulia; Paolucci, Stefano; Spadini, Ennio; Saraceni, Vincenzo Maria; Morone, Giovanni

    2015-01-01

    [Purpose] Recently, there has been growing interest in the somatosensory system, but little data exist on the interaction between dynamic postural control and the somatosensory system. The purpose of this study was to determine whether a training program, based on tactile and proprioceptive sensory stimulation of the trunk with the use of perceptual surfaces, improved the estimation of walking distance by healthy subjects, the ability to walk toward a memorized distance without vision, and whether it increases upright gait stability. [Subjects and Methods] Ten healthy subjects with a mean age of 31.9 ± 2.5 years were enrolled and participated in 10 daily sessions of perceptive training using perceptual surfaces, for 45 minutes each session. An experimental indoor test measured the subjects’ ability to perceive walking distances to a memorized target in an indoor environment. [Results] After treatment, the distances that were traversed were closer to the target than before treatment. Trunk acceleration did not differ significantly between pre- and post-training and did not increase significantly after training. [Conclusion] Treatment with perceptual surfaces stimulating the trunk midline improves the estimation of walking distance and modifies proprioceptive gait patterns, allowing various corrective strategies to be implemented during ambulation. PMID:26644695

  8. Evaluation of effects of different treatments for the wrist joints of subdominant hands using joint proprioception and writing time.

    PubMed

    Hu, Chunying; Huang, Qiuchen; Yu, Lili; Hu, Yue; Rongming, Xia; Li, Zhou; Xiaojiao, Fu; Gu, Rui; Cui, Yao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

    2016-05-01

    [Purpose] The purpose of this study was to examine immediate effects of strength training and NJF distal resistance training in wrist joints by using writing time and evaluation of proprioception using the JPE test. [Subjects and Methods] The subjects were 12 young healthy people (24.2 ± 3.1 y, 169.7 ± 6.5 cm, 65.3 ± 12.6 kg). Two isotonic contraction techniques were applied on the wrist joint: wrist joint extension muscle strength training (MST) and the wrist joint extension pattern of NJF. The uppercase English alphabet writing time and joint position errors of the left upper limb were measured before and after one intervention session of MST and NJF. [Results] The decrease in errors in wrist extension angle repetition and the writing time represented the improvement resulting from NJF. [Conclusion] This result suggests that the subdominant hands wrist joint proprioception and writing function can be improved by NJF together with proximal resistance training. PMID:27313380

  9. Proprioception of foot and ankle complex in young regular practitioners of ice hockey, ballet dancing and running.

    PubMed

    Li, Jing Xian; Xu, Dong Qing; Hoshizaki, Blaine

    2009-01-01

    This study examined the proprioception of the foot and ankle complex in regular ice hockey practitioners, runners, and ballet dancers. A total of 45 young people with different exercise habits formed four groups: the ice hockey, ballet dancing, running, and sedentary groups. Kinesthesia of the foot and ankle complex was measured in plantarflexion (PF), dorsiflexion (DF), inversion (IV), and eversion (EV) at 0.4 degrees /s using a custom-made device. The results showed the following: (1) significantly better perceived passive motion sense in PF/DF was found as compared with the measurements in IV/EV within each group (P < .01); (2) ice hockey and ballet groups perceived significantly better passive motion sense in IV/EV than the running (P < .05) and the sedentary (P < .01) groups; and (3) no significant difference in the all measurements was found between running and sedentary groups. The benefits of ice hockey and ballet dancing on proprioception may be associated with their movement characteristics.

  10. Prolonged use of Kinesiotaping does not enhance functional performance and joint proprioception in healthy young males: Randomized controlled trial

    PubMed Central

    Magalhães, Igor; Bottaro, Martim; Freitas, João R.; Carmo, Jake; Matheus, João P. C.; Carregaro, Rodrigo L.

    2016-01-01

    ABSTRACT Objectives The aim of this study was to investigate the effects of continuous (48-hour) use of Kinesiotaping (KT) on functional and proprioceptive performance in healthy, physically active men. Method Twenty-six healthy, physically active men (21.8±2.2 years old) were randomly allocated into two groups: 1) Kinesiotaping group (KG, tape applied with 40% tension for rectus femoris activation); 2) Control (CG, tape applied over rectus femoris without additional tension). Subjects attended the laboratory on five separate occasions: 1) familiarization; 2) baseline measurement without tape (BL); 3) immediately post-tape application (T0); 4) 24h (T24); and 5) 48h (T48) post-tape application. The outcomes were distance in the single (SHT) and triple hop tests (THT), vertical jump height (VJH), vertical jump power (VJP), and rate of force development (RFD). A mixed-model ANOVA was applied to verify differences between and within groups. Results No significant (p >0.05) differences were found in the SHT and THT between groups and moments. Likewise, the main effects for VJH, VJP, and RFD were not significant (p >0.05). Conclusion The present study demonstrated no significant immediate or prolonged (48h) effects of KT on functional and proprioceptive performance. PMID:27437712

  11. Evaluation of the effects of different treatments for the elbow joint using joint proprioception and surface electromyography.

    PubMed

    Huang, Qiuchen; Wang, Kuei-Yuan; Yu, Lili; Zhou, Yue; Gu, Rui; Cui, Yao; Hu, Chunying; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

    2015-12-01

    [Purpose] The purpose of this study was to examine the immediate effects of strength training and neuromuscular joint facilitation (NJF) distal resistance training on muscle strength and proprioception. [Subjects] The subjects were 15 young healthy people (29.3±4.1 y, 166.8±7.1 cm, 62.4 ± 11.6 ky). [Methods] Two isometric contraction techniques were applied on the elbow joint: elbow joint flexion muscle strength training (MST) and the elbow joint flexion pattern of NJF. Muscle strength (measured by surface electromyography [sEMG]) and joint position errors of the left upper limb were measured before and after one intervention session of MST and NJF. [Results] The decrease in error in elbow flexion angle repetition represented the improvement resulting from NJF. sEMG of the biceps brachii showed significant increases in the maximum discharge and average discharge after the intervention. [Conclusion] This result suggests that elbow joint proprioception and muscle strength can be improved by NJF together with proximal resistance training.

  12. Simple Phenomena, Slow Motion, Surprising Physics

    ERIC Educational Resources Information Center

    Koupil, Jan; Vicha, Vladimir

    2011-01-01

    This article describes a few simple experiments that are worthwhile for slow motion recording and analysis either because of interesting phenomena that can be seen only when slowed down significantly or because of the ability to do precise time measurements. The experiments described in this article are quite commonly done in Czech schools. All…

  13. Obsessional Slowness in College Students: Case Studies

    ERIC Educational Resources Information Center

    Johnson, Aleta

    2014-01-01

    Cases of obsessional slowness, a variant of obsessive compulsive disorder, have been documented in case literature regarding relatively low functioning populations. However, obsessional slowness can also present in higher functioning populations, including college and graduate students, as illustrated here by three case examples from a competitive…

  14. 49 CFR 236.813 - Speed, slow.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour....

  15. 49 CFR 236.813 - Speed, slow.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour....

  16. 49 CFR 236.813 - Speed, slow.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour....

  17. 49 CFR 236.813 - Speed, slow.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour....

  18. 49 CFR 236.813 - Speed, slow.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour....

  19. Staff Development for Teaching Slow Learners

    ERIC Educational Resources Information Center

    Leff, Rhona

    2008-01-01

    If you have noticed that your teachers need more "tricks up their sleeves" for working with slow learners, you can initiate a staff-development plan for changing that. Here are some suggestions for using the time, resources, and staff that you already have to improve the teaching of slow learners.

  20. Can Fast and Slow Intelligence Be Differentiated?

    ERIC Educational Resources Information Center

    Partchev, Ivailo; De Boeck, Paul

    2012-01-01

    Responses to items from an intelligence test may be fast or slow. The research issue dealt with in this paper is whether the intelligence involved in fast correct responses differs in nature from the intelligence involved in slow correct responses. There are two questions related to this issue: 1. Are the processes involved different? 2. Are the…

  1. Connecting slow earthquakes to huge earthquakes.

    PubMed

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes.

  2. Connecting slow earthquakes to huge earthquakes

    NASA Astrophysics Data System (ADS)

    Obara, Kazushige; Kato, Aitaro

    2016-07-01

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes.

  3. Computing Slow Manifolds of Saddle Type

    NASA Astrophysics Data System (ADS)

    Guckenheimer, John; Kuehn, Christian

    2009-01-01

    Slow manifolds are important geometric structures in the state spaces of dynamical systems with multiple time scales. This paper introduces an algorithm for computing trajectories on slow manifolds that are normally hyperbolic with both stable and unstable fast manifolds. We present two examples of bifurcation problems where these manifolds play a key role and a third example in which saddle-type slow manifolds are part of a traveling wave profile of a partial differential equation. Initial value solvers are incapable of computing trajectories on saddle-type slow manifolds, so the slow manifold of saddle type (SMST) algorithm presented here is formulated as a boundary value method. We take an empirical approach here to assessing the accuracy and effectiveness of the algorithm.

  4. Slow Movements of Bio-Inspired Limbs

    NASA Astrophysics Data System (ADS)

    Babikian, Sarine; Valero-Cuevas, Francisco J.; Kanso, Eva

    2016-10-01

    Slow and accurate finger and limb movements are essential to daily activities, but the underlying mechanics is relatively unexplored. Here, we develop a mathematical framework to examine slow movements of tendon-driven limbs that are produced by modulating the tendons' stiffness parameters. Slow limb movements are driftless in the sense that movement stops when actuations stop. We demonstrate, in the context of a planar tendon-driven system representing a finger, that the control of stiffness suffices to produce stable and accurate limb postures and quasi-static (slow) transitions among them. We prove, however, that stable postures are achievable only when tendons are pretensioned, i.e., they cannot become slack. Our results further indicate that a non-smoothness in slow movements arises because the precision with which individual stiffnesses need to be altered changes substantially throughout the limb's motion.

  5. Connecting slow earthquakes to huge earthquakes.

    PubMed

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes. PMID:27418504

  6. Crossed hands strengthen and diversify proprioceptive drift in the self-touch illusion

    PubMed Central

    Kodaka, Kenri; Ishihara, Yuki

    2014-01-01

    In the self-touch illusion (STI), some can feel that both hands are touching each other even when they are separated actually. This is achieved by giving synchronized touches to both hands. Because the STI involves both hands (an administrating hand and a receptive hand) of a single person, two types of proprioceptive drifts (PDs) simultaneously occur in such a way that both hands are attracted to each other. It is known that the PD distance is generally larger for the administrating hand than for the receptive hand when the two hands are uncrossed. However, it remains unclear why such an asymmetrical relationship is observed universally. In this study, we conducted two types of experiment to induce the STI. The first experiment involved four conditions combining a factor of “whether the hands are uncrossed or crossed” and a factor of “whether the administrating hand is resting or active on the surface,” with the receptive (left) hand located at the body's midline. The result demonstrated that crossing hands and resting on surface (ROS) induced the STI. Specifically, crossing hands enhanced the amount of PD distance by more than two or three times. Moreover, it is interesting that strong PD with dominance of the receptive hand, which did not appear in the uncrossed condition, was observed frequently. The second experiment collected seven “illusion-sensitive” participants from the first experiment, all of whom had a strong tendency to feel the self-touch, and examined the effect of the location of the body midline on the PD when hands are crossed with the administrating hand ROS. The result demonstrated that the dominant hand on the PD completely differed among participants, but was relatively stable over the midline position and time in the same person. We also found that a small number of participants exhibited quite a different pattern of the PD in the identical posture. On the basis of the results, we analyze in detail how the dominant hand on the PD

  7. The proprioceptive reflex control of the intercostal muscles during their voluntary activation.

    PubMed

    Davis, J N; Sears, T A

    1970-08-01

    external airway resistance.9. It is argued that the IR is due to autogenetic inhibition arising from tendon organs and that the ER is due to autogenetic excitation arising from intercostal muscle spindles.10. The initial dominance of inhibition in this dual proprioceptive reflex control was not predicted by the servo theory. It is proposed that the reflex pathways subserving autogenetic inhibition are under a centrifugal control which determines in relation to previous experience (learning) the conditions under which autogenetic facilitation is allowed.

  8. Efficacy of static stretching and proprioceptive neuromuscular facilitation stretch on hamstrings length after a single session.

    PubMed

    O'Hora, John; Cartwright, Abigail; Wade, Clive D; Hough, Alan D; Shum, Gary L K

    2011-06-01

    A number of studies have investigated the efficacy of several repetitions of proprioceptive neuromuscular facilitation stretching (PNF) and static stretching (SS). However, there is limited research comparing the effects of a single bout of these stretching maneuvers. The aim of this study was to compare the effectiveness of a single bout of a therapist-applied 30-second SS vs. a single bout of therapist-applied 6-second hamstring (agonist) contract PNF. Forty-five healthy subjects between the ages of 21 and 35 were randomly allocated to 1 of the 2 stretching groups or a control group, in which no stretching was received. The flexibility of the hamstring was determined by a range of passive knee extension, measured using a universal goniometer, with the subject in the supine position and the hip at 90° flexion, before and after intervention. A significant increase in knee extension was found for both intervention groups after a single stretch (SS group = 7.53°, p < 0.01 and PNF group = 11.80°, p < 0.01). Both interventions resulted in a significantly greater increase in knee extension when compared to the control group (p < 0.01). The PNF group demonstrated significantly greater gains in knee extension compared to the SS group (mean difference 4.27°, p < 0.01). It can be concluded that a therapist applied SS or PNF results in a significant increase in hamstring flexibility. A hamstring (agonist) contract PNF is more effective than an SS in a single stretching session. These findings are important to physiotherapists or trainers working in clinical and sporting environments. Where in the past therapists may have spent time conducting multiple repetitions of a PNF and an SS, a single bout of either technique may be considered just as effective. A key component of the study methodology was the exclusion of a warm-up period before stretching. Therefore, the findings of efficacy of a single PNF are of particular relevance in sporting environments and busy clinical

  9. Effect of proprioceptive training on foot posture, lower limb alignment, and knee adduction moment in patients with degenerative knee osteoarthritis: a randomized controlled trial

    PubMed Central

    Cho, Yumi; Kim, Minkyu; Lee, Wanhee

    2015-01-01

    [Purpose] The purpose of this study was to determine the effect of proprioceptive training on foot progression angle, weight-bearing ratio, and knee adduction moment in patients with degenerative osteoarthritis of the knee. [Subjects] The subjects were 37 patients diagnosed with Kellgren-Lawrence grade 2 or 3 degenerative knee osteoarthritis. They were randomly allocated to three groups: a proprioceptive training group (PT group), quadriceps strengthening group (QS group), and control group. [Methods] The study parameters of the three groups were compared before and after a 12-week training period. Therapeutic exercises were performed twice per week for 12 weeks. Outcomes included the foot progression angle, weight-bearing ratio, and knee adduction moment. [Results] First, a significant difference in the foot progression angle was observed among the groups, significantly increasing in the PTG compared with the CG. Second, a significant difference in the weight-bearing ratio was observed among the groups, significantly increasing in the PTG compared with the CG. Third, a significant difference in the first peak knee adduction moment was observed among the groups, significantly decreasing in the PTG compared with the CG. [Conclusion] The results of the present study indicate that proprioceptive training increased the foot progression angle and weight-bearing ratio and decreased the first peak knee adduction moment. Moreover, incorporating proprioceptive training into a physical therapy exercise program could improve functional ability and delay the progression of degenerative osteoarthritis. PMID:25729170

  10. Sleep dissolves illusion: sleep withstands learning of visuo-tactile-proprioceptive integration induced by repeated days of rubber hand illusion training.

    PubMed

    Honma, Motoyasu; Yoshiike, Takuya; Ikeda, Hiroki; Kim, Yoshiharu; Kuriyama, Kenichi

    2014-01-01

    Multisensory integration is a key factor in establishing bodily self-consciousness and in adapting humans to novel environments. The rubber hand illusion paradigm, in which humans can immediately perceive illusory ownership to an artificial hand, is a traditional technique for investigating multisensory integration and the feeling of illusory ownership. However, the long-term learning properties of the rubber hand illusion have not been previously investigated. Moreover, although sleep contributes to various aspects of cognition, including learning and memory, its influence on illusory learning of the artificial hand has not yet been assessed. We determined the effects of daily repetitive training and sleep on learning visuo-tactile-proprioceptive sensory integration and illusory ownership in healthy adult participants by using the traditional rubber hand illusion paradigm. Subjective ownership of the rubber hand, proprioceptive drift, and galvanic skin response were measured to assess learning indexes. Subjective ownership was maintained and proprioceptive drift increased with daily training. Proprioceptive drift, but not subjective ownership, was significantly attenuated after sleep. A significantly greater reduction in galvanic skin response was observed after wakefulness compared to after sleep. Our results suggest that although repetitive rubber hand illusion training facilitates multisensory integration and physiological habituation of a multisensory incongruent environment, sleep corrects illusional integration and habituation based on experiences in a multisensory incongruent environment. These findings may increase our understanding of adaptive neural processes to novel environments, specifically, bodily self-consciousness and sleep-dependent neuroplasticity. PMID:24465671

  11. Effect of proprioceptive training on foot posture, lower limb alignment, and knee adduction moment in patients with degenerative knee osteoarthritis: a randomized controlled trial.

    PubMed

    Cho, Yumi; Kim, Minkyu; Lee, Wanhee

    2015-02-01

    [Purpose] The purpose of this study was to determine the effect of proprioceptive training on foot progression angle, weight-bearing ratio, and knee adduction moment in patients with degenerative osteoarthritis of the knee. [Subjects] The subjects were 37 patients diagnosed with Kellgren-Lawrence grade 2 or 3 degenerative knee osteoarthritis. They were randomly allocated to three groups: a proprioceptive training group (PT group), quadriceps strengthening group (QS group), and control group. [Methods] The study parameters of the three groups were compared before and after a 12-week training period. Therapeutic exercises were performed twice per week for 12 weeks. Outcomes included the foot progression angle, weight-bearing ratio, and knee adduction moment. [Results] First, a significant difference in the foot progression angle was observed among the groups, significantly increasing in the PTG compared with the CG. Second, a significant difference in the weight-bearing ratio was observed among the groups, significantly increasing in the PTG compared with the CG. Third, a significant difference in the first peak knee adduction moment was observed among the groups, significantly decreasing in the PTG compared with the CG. [Conclusion] The results of the present study indicate that proprioceptive training increased the foot progression angle and weight-bearing ratio and decreased the first peak knee adduction moment. Moreover, incorporating proprioceptive training into a physical therapy exercise program could improve functional ability and delay the progression of degenerative osteoarthritis.

  12. Sleep dissolves illusion: sleep withstands learning of visuo-tactile-proprioceptive integration induced by repeated days of rubber hand illusion training.

    PubMed

    Honma, Motoyasu; Yoshiike, Takuya; Ikeda, Hiroki; Kim, Yoshiharu; Kuriyama, Kenichi

    2014-01-01

    Multisensory integration is a key factor in establishing bodily self-consciousness and in adapting humans to novel environments. The rubber hand illusion paradigm, in which humans can immediately perceive illusory ownership to an artificial hand, is a traditional technique for investigating multisensory integration and the feeling of illusory ownership. However, the long-term learning properties of the rubber hand illusion have not been previously investigated. Moreover, although sleep contributes to various aspects of cognition, including learning and memory, its influence on illusory learning of the artificial hand has not yet been assessed. We determined the effects of daily repetitive training and sleep on learning visuo-tactile-proprioceptive sensory integration and illusory ownership in healthy adult participants by using the traditional rubber hand illusion paradigm. Subjective ownership of the rubber hand, proprioceptive drift, and galvanic skin response were measured to assess learning indexes. Subjective ownership was maintained and proprioceptive drift increased with daily training. Proprioceptive drift, but not subjective ownership, was significantly attenuated after sleep. A significantly greater reduction in galvanic skin response was observed after wakefulness compared to after sleep. Our results suggest that although repetitive rubber hand illusion training facilitates multisensory integration and physiological habituation of a multisensory incongruent environment, sleep corrects illusional integration and habituation based on experiences in a multisensory incongruent environment. These findings may increase our understanding of adaptive neural processes to novel environments, specifically, bodily self-consciousness and sleep-dependent neuroplasticity.

  13. Slow-Slip Propagation Speeds

    NASA Astrophysics Data System (ADS)

    Rubin, A. M.; Ampuero, J.

    2007-12-01

    Combined seismic and geodetic data from subduction zones and the Salton Trough have revealed slow slip events with reasonably well-defined propagation speeds. This in turn is suggestive of a more-or-less well- defined front separating nearly locked regions outside the slipping zone from interior regions that slide much more rapidly. Such crack-like nucleation fronts arise naturally in models of rate-and-state friction for lab-like values of a/b, where a and b are the coefficients of the velocity- and state-dependence of the frictional strength (with the surface being velocity-neutral for a/b=1). If the propagating front has a quasi-steady shape, the propagation and slip speeds are kinematically tied via the local slip gradient. Given a sufficiently sharp front, the slip gradient is given dimensionally by Δτp- r/μ', where Δτp-r is the peak-to-residual stress drop at the front and μ' the effective elastic shear modulus. Rate-and-state simulations indicate that Δτp-r is given reasonably accurately by bσ\\ln(Vmaxθi/Dc), where σ is the effective normal stress, Vmax is the maximum slip speed behind the propagating front, θi is the the value of "state" ahead of the propagating front, and Dc is the characteristic slip distance for state evolution. Except for a coefficient of order unity, Δτp-r is independent of the evolution law. This leads to Vprop/Vmax ~μ'/[bσ\\ln(Vmaxθi/Dc)]. For slip speeds a few orders of magnitude above background, \\ln(Vmaxθi/Dc) can with reasonable accuracy be assigned some representative value (~4-5, for example). Subduction zone transients propagate on the order of 10 km/day or 10-1 m/s. Geodetic data constrain the average slip speed to be a few times smaller than 1 cm/day or 10-7 m/s. However, numerical models indicate that the maximum slip speed at the front may be several times larger than the average, over a length scale that is probably too small to resolve geodetically, so a representative value of Vprop/Vmax may be ~106

  14. Linking Sleep Slow Oscillations with consciousness theories: new vistas on Slow Wave Sleep unconsciousness.

    PubMed

    Gemignani, Angelo; Menicucci, Danilo; Laurino, Marco; Piarulli, Andrea; Mastorci, Francesca; Sebastiani, Laura; Allegrini, Paolo

    2015-01-01

    We review current models of consciousness in the context of wakefulness and sleep. We show that recent results on Slow Wave Sleep, including our own works, naturally fit within consciousness models. In particular, Sleep Slow Oscillations, namely low-frequency (<1Hz) oscillations, contain electrophysiological properties (up and down states) able to elicit and quench neural integration during Slow Wave Sleep. The physiological unconsciousness related to the Sleep Slow Oscillation derives from the interplay between spontaneous or evoked wake-like activities (up states) and half-a-second's electrical silences (down states). Sleep Slow Oscillation induces unconsciousness via the formation of parallel and segregated neural activities. PMID:26742667

  15. KEK-IMSS Slow Positron Facility

    NASA Astrophysics Data System (ADS)

    Hyodo, T.; Wada, K.; Yagishita, A.; Kosuge, T.; Saito, Y.; Kurihara, T.; Kikuchi, T.; Shirakawa, A.; Sanami, T.; Ikeda, M.; Ohsawa, S.; Kakihara, K.; Shidara, T.

    2011-12-01

    The Slow Positron Facility at the Institute of Material Structure Science (IMSS) of High Energy Accelerator Research Organization (KEK) is a user dedicated facility with an energy tunable (0.1 - 35 keV) slow positron beam produced by a dedicated 55MeV linac. The present beam line branches have been used for the positronium time-of-flight (Ps-TOF) measurements, the transmission positron microscope (TPM) and the photo-detachment of Ps negative ions (Ps-). During the year 2010, a reflection high-energy positron diffraction (RHEPD) measurement station is going to be installed. The slow positron generator (converter/ moderator) system will be modified to get a higher slow positron intensity, and a new user-friendly beam line power-supply control and vacuum monitoring system is being developed. Another plan for this year is the transfer of a 22Na-based slow positron beam from RIKEN. This machine will be used for the continuous slow positron beam applications and for the orientation training of those who are interested in beginning researches with a slow positron beam.

  16. Slow Modes in Convecting Liquid Metal

    NASA Astrophysics Data System (ADS)

    Aurnou, J. M.; Ribeiro, A.; Calkins, M. A.; Julien, K. A.

    2015-12-01

    Slow, large-scale magnetostrophic wave modes are expected to develop in rapidly-rotating magnetohydrodynamic systems. These slow modes arise due to a leading order balance between Coriolis and Lorentz forces, with negligible effects of fluid inertia. Such slow modes have long been argued to be the primary cause of the long period (e.g., century-scale) variations in observations of the geomagnetic field. Yet, to date, such slow modes have yet to develop in global-scale numerical models of planetary dynamo action. Here we present the results of closely coupled laboratory-numerical simulations of rapidly rotating magnetoconvection in liquid gallium, in which we find strong evidence for slow modes developing near, as well as beyond, the onset of convection. Preliminary results from an associated survey of numerical simulations are allowing us to determine under what range of conditions slow convective modes exist. Thus far, it appears they develop only in low Prandtl number fluids, in which the thermal diffusivity significantly exceeds the viscous diffusivity, as occurs in liquid metals. Our findings suggest more metal-like fluid properties are necessary for the development of slow modes in convection-driven global-scale dynamo models.

  17. Large Deviations in Fast-Slow Systems

    NASA Astrophysics Data System (ADS)

    Bouchet, Freddy; Grafke, Tobias; Tangarife, Tomás; Vanden-Eijnden, Eric

    2016-02-01

    The incidence of rare events in fast-slow systems is investigated via analysis of the large deviation principle (LDP) that characterizes the likelihood and pathway of large fluctuations of the slow variables away from their mean behavior—such fluctuations are rare on short time-scales but become ubiquitous eventually. Classical results prove that this LDP involves an Hamilton-Jacobi equation whose Hamiltonian is related to the leading eigenvalue of the generator of the fast process, and is typically non-quadratic in the momenta—in other words, the LDP for the slow variables in fast-slow systems is different in general from that of any stochastic differential equation (SDE) one would write for the slow variables alone. It is shown here that the eigenvalue problem for the Hamiltonian can be reduced to a simpler algebraic equation for this Hamiltonian for a specific class of systems in which the fast variables satisfy a linear equation whose coefficients depend nonlinearly on the slow variables, and the fast variables enter quadratically the equation for the slow variables. These results are illustrated via examples, inspired by kinetic theories of turbulent flows and plasma, in which the quasipotential characterizing the long time behavior of the system is calculated and shown again to be different from that of an SDE.

  18. Motor Learning Relies on Integrated Sensory Inputs in ADHD, but Over-Selectively on Proprioception in Autism Spectrum Conditions

    PubMed Central

    Izawa, Jun; Pekny, Sarah E; Marko, Mollie K; Haswell, Courtney C; Shadmehr, Reza; Mostofsky, Stewart H

    2012-01-01

    those in children with Attention Deficit Hyperactivity Disorder (ADHD). Consistent with our previous observations, we found that in ASD the motor memory showed greater than normal generalization in proprioceptive coordinates compared with both TD children and children with ADHD; children with ASD also showed slower rates of adaptation compared with both control groups. Children with ADHD did not show this excessive generalization to the proprioceptive target, but did show excessive variability in the speed of movements with an increase in the exponential distribution of responses (τ) as compared with both TD children and children with ASD. The results suggest that slower rate of adaptation and anomalous bias towards proprioceptive feedback during motor learning is characteristic of autism; whereas increased variability in execution is characteristic of ADHD. PMID:22359275

  19. Slow electron cooling in colloidal quantum dots.

    PubMed

    Pandey, Anshu; Guyot-Sionnest, Philippe

    2008-11-01

    Hot electrons in semiconductors lose their energy very quickly (within picoseconds) to lattice vibrations. Slowing this energy loss could prove useful for more efficient photovoltaic or infrared devices. With their well-separated electronic states, quantum dots should display slow relaxation, but other mechanisms have made it difficult to observe. We report slow intraband relaxation (>1 nanosecond) in colloidal quantum dots. The small cadmium selenide (CdSe) dots, with an intraband energy separation of approximately 0.25 electron volts, are capped by an epitaxial zinc selenide (ZnSe) shell. The shell is terminated by a CdSe passivating layer to remove electron traps and is covered by ligands of low infrared absorbance (alkane thiols) at the intraband energy. We found that relaxation is markedly slowed with increasing ZnSe shell thickness.

  20. Neuroticism, extraversion and slow brain potentials.

    PubMed

    Lolas, F; de Andraca, I

    1977-01-01

    Peak amplitude and area under the curve of average vertex slow potentials recorded during the foreperiod of a reaction time task were found to discriminate between high- and low-neuroticism subjects, defined according to the Eysenck Personality Inventory. High-neuroticism subjects developed smaller peak amplitude, greater area and longer reaction times, presenting a high extinction rate when the imperative stimulus was omitted. Differences between extraverts and introverts were found within the low-neuroticism group and for area values, extraverts exhibiting larger area. A significant interaction effect of extraversion and neuroticism on slow-potential parameters was evidenced. Results are interpreted in terms of heightened arousal and disrupted focused attention in high-neuroticism subjects. Although evolutionary indexes of slow potentials could differentiate between extraverts and introverts, further work using inhibition indicators is needed to further clarify the differences between them. The data reported also suggest that different aspects of overt behavior would be associated diversely with slow-potential parameters.

  1. New developments in slow sand filtration

    SciTech Connect

    Fox, K.R.

    1993-01-01

    Recent regulations promulgated by the U.S. Environmental Protection Agency (EPA), including the Surface Water Treatment Rule, have helped to renew the interest in the use of slow sand filtration (SSF) for treating surface waters for small communities. Slow sand filtration is not a new process, but is one that has been used to treat water effectively since the early 1800's. Interest in slow sand filtration in the United States has increased dramatically in the past thirteen years. New analytical techniques, such as particle counting, improved turbidity, improved growth media for microbiological analysis, and advanced techniques for measuring organic constituents allowed for more detailed studies than were possible in the early 1900's. The new work led to the publication of design manuals and task committee reports describing slow sand filtration in detail.

  2. Experimental demonstration of spinor slow light

    NASA Astrophysics Data System (ADS)

    Lee, Meng-Jung; Ruseckas, Julius; Lee, Chin-Yuan; Kudriašov, Viačeslav; Chang, Kao-Fang; Cho, Hung-Wen; JuzeliÅ«nas, Gediminas; Yu, Ite A.

    2016-03-01

    Over the last decade there has been a continuing interest in slow and stored light based on the electromagnetically induced transparency (EIT) effect, because of their potential applications in quantum information manipulation. However, previous experimental works all dealt with the single-component slow light which cannot be employed as a qubit. In this work, we report the first experimental demonstration of two-component or spinor slow light (SSL) using a double tripod (DT) atom-light coupling scheme. The oscillations between the two components, similar to the Rabi oscillation of a two-level system or a qubit, were observed. Single-photon SSL can be considered as two-color qubits. We experimentally demonstrated a possible application of the DT scheme as quantum memory and quantum rotator for the two-color qubits. This work opens up a new direction in the slow light research.

  3. Structural processes at slow-spreading ridges.

    PubMed

    Mutter, J C; Karson, J A

    1992-07-31

    Slow-spreading (<35 millimeters per year) mid-ocean ridges are dominated by segmented, asymmetric, rifted depressions like continental rifts. Fast-spreading ridges display symmetric, elevated volcanic edifices that vary in shape and size along axis. Deep earthquakes, major normal faults, and exposures of lower crustal rocks are common only along slow-spreading ridges. These contrasting features suggest that mechanical deformation is far more important in crustal formation at slow-spreading ridges than at fast-spreading ridges. New seismic images suggest that the nature and scale of segmentation of slow-spreading ridges is integral to the deformational process and not to magmatic processes that may control segmentation on fast-spreading ridges.

  4. The quiescent corona and slow solar wind

    NASA Technical Reports Server (NTRS)

    Noci, G.; Kohl, J. L.; Antonucci, E.; Tondello, G.; Huber, M. C. E.; Fineschi, S.; Gardner, L. D.; Korendyke, C. M.; Nicolosi, P.; Romoli, M.; Spadaro, D.; Maccari, L.; Raymond, J. C.; Siegmund, O. H. W.; Benna, C.; Ciaravella, A.; Giordano, S.; Michels, J.; Modigliani, A.; Naletto, G.

    1997-01-01

    The observations of the ultraviolet coronagraph spectrometer (UVCS), operating onboard the Solar and Heliospheric Observatory (SOHO) spacecraft, are discussed. The purpose of the UVCS is the study of the quiescent coronal streamer and the slow solar wind. The observations started in January 1996. Polarized radiance data in the visible continuum were obtained. Some characteristics of the coronal streamer from the UVCS recorded data are discussed. A model for the source of the slow solar wind in the inner corona is proposed.

  5. The rubber hand illusion in children with autism spectrum disorders: delayed influence of combined tactile and visual input on proprioception

    PubMed Central

    Cascio, Carissa J.; Foss-Feig, Jennifer H.; Burnette, Courtney P.; Heacock, Jessica L.; Cosby, Akua A.

    2012-01-01

    In the rubber hand illusion, perceived hand ownership can be transferred to a rubber hand after synchronous visual and tactile stimulation. Perceived body ownership and self–other relation are foundational for development of self-awareness, imitation, and empathy, which are all affected in autism spectrum disorders (ASD). We examined the rubber hand illusion in children with and without ASD. Children with ASD were initially less susceptible to the illusion than the comparison group, yet showed the effects of the illusion after 6 minutes. Delayed susceptibility to the illusion may result from atypical multisensory temporal integration and/or an unusually strong reliance on proprioception. Children with ASD who displayed less empathy were significantly less likely to experience the illusion than those with more intact ability to express empathy. A better understanding of body representation in ASD may elucidate neural underpinnings of social deficits, thus informing future intervention approaches. PMID:22399451

  6. Hemispheric specificity for proprioception: Postural control of standing following right or left hemisphere damage during ankle tendon vibration.

    PubMed

    Duclos, Noémie C; Maynard, Luc; Abbas, Djawad; Mesure, Serge

    2015-11-01

    Right brain damage (RBD) following stroke often causes significant postural instability. In standing (without vision), patients with RBD are more unstable than those with left brain damage (LBD). We hypothesised that this postural instability would relate to the cortical integration of proprioceptive afferents. The aim of this study was to use tendon vibration to investigate whether these changes were specific to the paretic or non-paretic limbs. 14 LBD, 12 RBD patients and 20 healthy subjects were included. Displacement of the Centre of Pressure (CoP) was recorded during quiet standing, then during 3 vibration conditions (80 Hz - 20s): paretic limb, non-paretic limb (left and right limbs for control subjects) and bilateral. Vibration was applied separately to the peroneal and Achilles tendons. Mean antero-posterior position of the CoP, variability and velocity were calculated before (4s), during and after (24s) vibration. For all parameters, the strongest perturbation was during Achilles vibrations. The Achilles non-paretic condition induced a larger backward displacement than the Achilles paretic condition. This condition caused specific behaviour on the velocity: the LBD group was perturbed at the onset of the vibrations, but gradually recovered their stability; the RBD group was significantly perturbed thereafter. After bilateral Achilles vibration, RBD patients required the most time to restore initial posture. The reduction in use of information from the paretic limb may be a central strategy to deal with risk-of-fall situations such as during Achilles vibration. The postural behaviour is profoundly altered by lesions of the right hemisphere when proprioception is perturbed. PMID:26358149

  7. Hemispheric specificity for proprioception: Postural control of standing following right or left hemisphere damage during ankle tendon vibration.

    PubMed

    Duclos, Noémie C; Maynard, Luc; Abbas, Djawad; Mesure, Serge

    2015-11-01

    Right brain damage (RBD) following stroke often causes significant postural instability. In standing (without vision), patients with RBD are more unstable than those with left brain damage (LBD). We hypothesised that this postural instability would relate to the cortical integration of proprioceptive afferents. The aim of this study was to use tendon vibration to investigate whether these changes were specific to the paretic or non-paretic limbs. 14 LBD, 12 RBD patients and 20 healthy subjects were included. Displacement of the Centre of Pressure (CoP) was recorded during quiet standing, then during 3 vibration conditions (80 Hz - 20s): paretic limb, non-paretic limb (left and right limbs for control subjects) and bilateral. Vibration was applied separately to the peroneal and Achilles tendons. Mean antero-posterior position of the CoP, variability and velocity were calculated before (4s), during and after (24s) vibration. For all parameters, the strongest perturbation was during Achilles vibrations. The Achilles non-paretic condition induced a larger backward displacement than the Achilles paretic condition. This condition caused specific behaviour on the velocity: the LBD group was perturbed at the onset of the vibrations, but gradually recovered their stability; the RBD group was significantly perturbed thereafter. After bilateral Achilles vibration, RBD patients required the most time to restore initial posture. The reduction in use of information from the paretic limb may be a central strategy to deal with risk-of-fall situations such as during Achilles vibration. The postural behaviour is profoundly altered by lesions of the right hemisphere when proprioception is perturbed.

  8. Slow slip and the transition from fast to slow fronts in the rupture of frictional interfaces.

    PubMed

    Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Scheibert, Julien; Thøgersen, Kjetil; Amundsen, David Skålid; Malthe-Sørenssen, Anders

    2014-06-17

    The failure of the population of microjunctions forming the frictional interface between two solids is central to fields ranging from biomechanics to seismology. This failure is mediated by the propagation along the interface of various types of rupture fronts, covering a wide range of velocities. Among them are the so-called slow fronts, which are recently discovered fronts much slower than the materials' sound speeds. Despite intense modeling activity, the mechanisms underlying slow fronts remain elusive. Here, we introduce a multiscale model capable of reproducing both the transition from fast to slow fronts in a single rupture event and the short-time slip dynamics observed in recent experiments. We identify slow slip immediately following the arrest of a fast front as a phenomenon sufficient for the front to propagate further at a much slower pace. Whether slow fronts are actually observed is controlled both by the interfacial stresses and by the width of the local distribution of forces among microjunctions. Our results show that slow fronts are qualitatively different from faster fronts. Because the transition from fast to slow fronts is potentially as generic as slow slip, we anticipate that it might occur in the wide range of systems in which slow slip has been reported, including seismic faults. PMID:24889640

  9. Analysis of Slow-Wave Activity and Slow-Wave Oscillations Prior to Somnambulism

    PubMed Central

    Jaar, Olivier; Pilon, Mathieu; Carrier, Julie; Montplaisir, Jacques; Zadra, Antonio

    2010-01-01

    Study Objectivies: Several studies have investigated slow wave sleep EEG parameters, including slow-wave activity (SWA) in relation to somnambulism, but results have been both inconsistent and contradictory. The first goal of the present study was to conduct a quantitative analysis of sleepwalkers' sleep EEG by studying fluctuations in spectral power for delta (1-4 Hz) and slow delta (0.5-1 Hz) before the onset of somnambulistic episodes. A secondary aim was to detect slow-wave oscillations to examine changes in their amplitude and density prior to behavioral episodes. Participants: Twenty-two adult sleepwalkers were investigated polysomnographically following 25 h of sleep deprivation. Results: Analysis of patients' sleep EEG over the 200 sec prior to the episodes' onset revealed that the episodes were not preceded by a gradual increase in spectral power for either delta or slow delta over frontal, central, or parietal leads. However, time course comparisons revealed significant changes in the density of slow-wave oscillations as well as in very slow oscillations with significant increases occurring during the final 20 sec immediately preceding episode onset. Conclusions: The specificity of these sleep EEG parameters for the occurrence and diagnosis of NREM parasomnias remains to be determined. Citation: Jaar O; Pilon M; Carrier J; Montplaisir J; Zadra A. Analysis of slow-wave activity and slow-wave oscillations prior to somnambulism. SLEEP 2010;33(11):1511-1516. PMID:21102993

  10. Global Network of Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Crooker, N. U.; Antiochos, S. K.; Zhao, X.; Neugebauer, M.

    2012-01-01

    The streamer belt region surrounding the heliospheric current sheet (HCS) is generally treated as the primary or sole source of the slow solar wind. Synoptic maps of solar wind speed predicted by the Wang-Sheeley-Arge model during selected periods of solar cycle 23, however, show many areas of slow wind displaced from the streamer belt. These areas commonly have the form of an arc that is connected to the streamer belt at both ends. The arcs mark the boundaries between fields emanating from different coronal holes of the same polarity and thus trace the paths of belts of pseudostreamers, i.e., unipolar streamers that form over double arcades and lack current sheets. The arc pattern is consistent with the predicted topological mapping of the narrow open corridor or singular separator line that must connect the holes and, thus, consistent with the separatrix-web model of the slow solar wind. Near solar maximum, pseudostreamer belts stray far from the HCS-associated streamer belt and, together with it, form a global-wide web of slow wind. Recognition of pseudostreamer belts as prominent sources of slow wind provides a new template for understanding solar wind stream structure, especially near solar maximum.

  11. Global network of slow solar wind

    NASA Astrophysics Data System (ADS)

    Crooker, N. U.; Antiochos, S. K.; Zhao, X.; Neugebauer, M.

    2012-04-01

    The streamer belt region surrounding the heliospheric current sheet (HCS) is generally treated as the primary or sole source of the slow solar wind. Synoptic maps of solar wind speed predicted by the Wang-Sheeley-Arge model during selected periods of solar cycle 23, however, show many areas of slow wind displaced from the streamer belt. These areas commonly have the form of an arc that is connected to the streamer belt at both ends. The arcs mark the boundaries between fields emanating from different coronal holes of the same polarity and thus trace the paths of belts of pseudostreamers, i.e., unipolar streamers that form over double arcades and lack current sheets. The arc pattern is consistent with the predicted topological mapping of the narrow open corridor or singular separator line that must connect the holes and, thus, consistent with the separatrix-web model of the slow solar wind. Near solar maximum, pseudostreamer belts stray far from the HCS-associated streamer belt and, together with it, form a global-wide web of slow wind. Recognition of pseudostreamer belts as prominent sources of slow wind provides a new template for understanding solar wind stream structure, especially near solar maximum.

  12. Topological Origins of the Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Antiochos, Spiro

    2008-01-01

    Although the slow solar wind has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow wind is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the other hand, the slow wind is postulated to originate on open flux that is dynamically diffusing throughout the seemingly closed-field corona. We argue in favor of the quasi-steady scenario and propose that the slow wind is due to two effects: First, the open-closed boundary is highly complex due to the complexity of the photospheric flux distribution. Second, this boundary is continuously driven by the transport of magnetic helicity from the closed field region into the open. The implications of this model for the structure and dynamics of the corona and slow wind are discussed, and observational tests of the mode

  13. Primordial perturbations during a slow expansion

    NASA Astrophysics Data System (ADS)

    Piao, Yun-Song

    2007-10-01

    Recently, it has been shown that a slow expansion, which is asymptotically a static state in infinite past and may be described as an evolution with γ≪-1, of early universe may lead to the generation of primordial perturbation responsible for the structure formation of observable universe. However, its feasibility depends on whether the growing mode of Bardeen potential before phase transition can be inherited by the constant mode of curvature perturbation after phase transition. In this paper, we phenomenally regard this slow expansion as that driven by multi-NEC (null energy condition) violating scalar fields. We calculate the curvature perturbation induced by the entropy perturbation before phase transition and find that the spectrum is naturally scale invariant with a slight red tilt. The result has an interesting similarity to that of slow roll inflation.

  14. OBSERVED DAMPING OF THE SLOW MAGNETOACOUSTIC MODE

    SciTech Connect

    Marsh, M. S.; Walsh, R. W.; De Moortel, I. E-mail: mmarsh@uclan.ac.uk

    2011-06-20

    Spectroscopic and stereoscopic imaging observations of slow magnetoacoustic wave propagation within a coronal loop are investigated to determine the decay length scale of the slow magnetoacoustic mode in three dimensions and the density profile within the loop system. The slow wave is found to have an e-folding decay length scale of 20,000{sup +4000}{sub -3000} km with a uniform density profile along the loop base. These observations place quantitative constraints on the modeling of wave propagation within coronal loops. Theoretical forward modeling suggests that magnetic field line divergence is the dominant damping factor and thermal conduction is insufficient, given the observed parameters of the coronal loop temperature, density, and wave mode period.

  15. Slow and fast light switching in ruby

    NASA Astrophysics Data System (ADS)

    Rajan, Rajitha P.; Riesen, Hans

    2015-05-01

    Studies about light propagation have been undertaken for more than a century. It is now well established that any material that has normal or anomalous dispersion generates slow or fast light. In this paper, we demonstrate an experimental technique to rapidly switch between slow and fast light in ruby. The experiment utilizes transient holeburning to create drastic variation in refractive index of ruby to produce slow as well as fast light. Transient hole-burning involves the depletion of the ground state leading to a highly populated excited state by single frequency laser excitation. This leads to a hole in the absorption spectrum when readout by a laser. We observed a delay of 29 ns and advancement of -11 ns in an external magnetic field of B║c = 12 mT corresponding to a group velocity of c/961 and negative group velocity of -c/365 respectively.

  16. Slowing presentation speed increases illusions of knowledge.

    PubMed

    Fazio, Lisa K; Marsh, Elizabeth J

    2008-02-01

    Prior research on false memories has shown that suggestibility is often reduced when the presentation rate is slowed enough to allow monitoring. We examined whether slowing presentation speed would reduce factual errors learned from fictional stories. Would subjects use the extra time to detect the errors in the stories, reducing reproduction of these errors on a later test? Surprisingly, slowing presentation speed increased the production of story errors on a later general knowledge test. Instructing the reader to mark whether each sentence contained an error, however, did decrease suggestibility. Readers appear to passively accept information presented in stories and need a constant reminder to monitor for errors. These results highlight differences between typical episodic false memories and illusions of knowledge (such as learning from fiction). Manipulations that reduce suggestibility for episodic false memories do not always reduce suggestibility for illusions of knowledge.

  17. Ultrafast Faraday Rotation of Slow Light

    NASA Astrophysics Data System (ADS)

    Musorin, A. I.; Sharipova, M. I.; Dolgova, T. V.; Inoue, M.; Fedyanin, A. A.

    2016-08-01

    The active control of optical signals in the time domain is what science and technology demand in fast all-optical information processing. Nanostructured materials can modify the group velocity and slow the light down, as the artificial light dispersion emerges. We observe the ultrafast temporal behavior of the Faraday rotation within a single femtosecond laser pulse under conditions of slow light in a one-dimensional magnetophotonic crystal. The Faraday effect changes by 20% over the time of 150 fs. This might be applicable to the fast control of light in high-capacity photonic devices.

  18. Slow crack growth in spinel in water

    NASA Technical Reports Server (NTRS)

    Schwantes, S.; Elber, W.

    1983-01-01

    Magnesium aluminate spinel was tested in a water environment at room temperature to establish its slow crack-growth behavior. Ring specimens with artificial flaws on the outside surface were loaded hydraulically on the inside surface. The time to failure was measured. Various precracking techniques were evaluated and multiple precracks were used to minimize the scatter in the static fatigue tests. Statistical analysis techniques were developed to determine the strength and crack velocities for a single flaw. Slow crack-growth rupture was observed at stress intensities as low as 70 percent of K sub c. A strengthening effect was observed in specimens that had survived long-time static fatigue tests.

  19. Geodynamic environments of ultra-slow spreading

    NASA Astrophysics Data System (ADS)

    Kokhan, Andrey; Dubinin, Evgeny

    2015-04-01

    Ultra-slow spreading is clearly distinguished as an outstanding type of crustal accretion by recent studies. Spreading ridges with ultra-slow velocities of extension are studied rather well. But ultra-slow spreading is characteristic feature of not only spreading ridges, it can be observed also on convergent and transform plate boundaries. Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on divergent plate boundaries: 1. On spreading ridges with ultra-slow spreading, both modern (f.e. Gakkel, South-West Indian, Aden spreading center) and ceased (Labrador spreading center, Aegir ridge); 2. During transition from continental rifting to early stages of oceanic spreading (all spreading ridges during incipient stages of their formation); 3. During incipient stages of formation of spreading ridges on oceanic crust as a result of ridge jumps and reorganization of plate boundaries (f.e. Mathematicians rise and East Pacific rise); 4. During propagation of spreading ridge into the continental crust under influence of hotspot (Aden spreading center and Afar triple junction), under presence of strike-slip faults preceding propagation (possibly, rift zone of California Bay). Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on transform plate boundaries: 1. In transit zones between two "typical" spreading ridges (f.e. Knipovich ridge); 2. In semi strike-slip/extension zones on the oceanic crust (f.e. American-Antarctic ridge); 3. In the zones of local extension in regional strike-slip areas in pull-apart basins along transform boundaries (Cayman trough, pull-apart basins of the southern border of Scotia plate). Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on convergent plate boundaries: 1. During back-arc rifting on the stage of transition into back-arc spreading (central

  20. Effects of passive correction of scapular position on pain, proprioception, and range of motion in neck-pain patients with bilateral scapular downward-rotation syndrome.

    PubMed

    Ha, Sung-min; Kwon, Oh-yun; Yi, Chung-hwi; Jeon, Hye-seon; Lee, Won-hwee

    2011-12-01

    The effects of passive correction of scapular position (PCSPT) on pain, proprioception, and range of motion (ROM) were investigated in neck-pain patients with bilateral scapular downward-rotation (SDR). Fifteen neck-pain patients with bilateral SDR were recruited from a workplace based work-conditioning center. The intensity of pain felt was quantified using a visual analogue scale. Kinematic data for ROM and joint-position error (JPE) were analyzed using a 3-dimensional motion-analysis system. Differences in pain, JPE, and ROM with and without PCSPT were assessed using a paired t-test. PCSPT significantly decreased JPE and neck pain during active neck rotation and significantly increased neck-rotation ROM (p < 0.05). These findings suggest that PCSPT results in decreased neck pain and improved neck-rotation ROM and proprioception during active neck rotation in neck-pain patients with bilateral SDR. PMID:21705260

  1. Slow breathing influences cardiac autonomic responses to postural maneuver: Slow breathing and HRV.

    PubMed

    Vidigal, Giovanna Ana de Paula; Tavares, Bruna S; Garner, David M; Porto, Andrey A; Carlos de Abreu, Luiz; Ferreira, Celso; Valenti, Vitor E

    2016-05-01

    Chronic slow breathing has been reported to improve Heart Rate Variability (HRV) in patients with cardiovascular disorders. However, it is not clear regarding its acute effects on HRV responses on autonomic analysis. We evaluated the acute effects of slow breathing on cardiac autonomic responses to postural change manoeuvre (PCM). The study was conducted on 21 healthy male students aged between 18 and 35 years old. In the control protocol, the volunteer remained at rest seated for 15 min under spontaneous breathing and quickly stood up within 3 s and remained standing for 15 min. In the slow breathing protocol, the volunteer remained at rest seated for 10 min under spontaneous breath, then performed slow breathing for 5 min and rapidly stood up within 3 s and remained standing for 15 min. Slow breathing intensified cardiac autonomic responses to postural maneuver. PMID:27157952

  2. Prescriptive proprioceptive insoles and dental orthotics change the frontal plane position of the atlas (C1), mastoid, malar, temporal, and sphenoid bones: a preliminary study.

    PubMed

    Rothbart, Brian A

    2013-10-01

    The purpose of this series of case studies was to determine if the frontal plane position of the cranial bones and atlas could be altered using dental orthotics, prescriptive insoles, or both concurrently. The cranial radiographs of four patients were reviewed for the study. Three of the patients were diagnosed as having a temporomandibular joint (TMJ) dysfunction and a preclinical clubfoot deformity. The fourth patient was diagnosed as having a TMJ dysfunction, a preclinical clubfoot deformity and a Catetgory II sacral occipital subluxation, as designated in the chiropractic's Sacro Occipital Technique (SOT). Each patient had a series of four cranial radiographs taken using a modified orthogonal protocol. In two patients, improvement towards orthogonal was achieved when using both prescriptive dental orthotics and prescriptive insoles concurrently. Improvement towards orthogonal was less apparent when using only the prescriptive dental orthotic. No improvement or a negative frontal plane shift was noted when using only the prescriptive proprioceptive insoles. In the third patient, the frontal plane position of the cranial bones and atlas increased (away from orthogonal) when using the generic proprioceptive insoles alone or in combination with a prescriptive dental orthotic. In the fourth patient, the frontal plane position of the cranial bones improved using the dental orthotic. However, the proprioceptive insoles, when used alone or in combination with the dental orthotic, increased the frontal plane position of the cranial bones and atlas. This study demonstrates that changes in the frontal plane position of the cranial and atlas bones can occur when using proprioceptive insoles and/or dental orthotics.

  3. Cortical mapping and laminar analysis of the cutaneous and proprioceptive inputs from the rat foreleg: an extra- and intra-cellular study.

    PubMed

    Gioanni, Y

    1987-01-01

    The foreleg proprioceptive and cutaneous representations, in the Sm cortex of urethane-anesthetized rats was studied. Natural or electrical stimulations and stretches of single forearm muscles were used. Multiunitary, unitary or intra-cellular recordings were performed in the contra-lateral Sm cortex. The aims of the study were: 1- to compare the proprioceptive and cutaneous maps 2- to analyse the characteristics of the unitary responses and 3- to study the laminar distribution of cutaneous and muscular inputs. It is shown that: 1- the proprioceptive and cutaneous representations overlapped, except in the anterior part where only proprioceptive (mainly articular) responses were obtained. The representation of each stretched muscle extended over the whole cutaneous area, showing a total overlap between inputs from these muscles. 2- 46% of the intracellularly recorded cells (n = 215) responded to peripheral stimulation, and 30.7% were influenced by (at least) muscle stretch. The majority of excited cells showed cross-modal convergence, and among neurons responding to muscle stretch, 60% received inputs from the two muscles stretched. Two categories of EPSPs were found, and four neurons responded to cutaneous or muscular stimulation with a burst. 19% of the responding cells were inhibited by peripheral--mainly cutaneous--stimulation. 3- Excited neurons were recorded in all layers, with just over half located in layer IV, whereas IPSPs were obtained mainly in layer V. The cells excited by cutaneous and muscular inputs (convergent neurons) were preponderant in layers IV to VI. This work shows that the cutaneous and muscular inputs reach the same area in Sm cortex, and that a majority of excited cells are "convergent". The results are not in favor of an area 3a (by analogy with cats and monkeys) in the rat. PMID:3653313

  4. Effects of trunk stability exercise using proprioceptive neuromuscular facilitation with changes in chair height on the gait of patients who had a stroke.

    PubMed

    Park, Si-Eun; Moon, Sang-Hyun

    2016-07-01

    [Purpose] The purpose of this study was to identify the effects of trunk stability exercise using proprioceptive neuromuscular facilitation with changes in chair heights on the gait of stroke patients. [Subjects and Methods] The subjects of this study were 11 stroke patients. The intervention method was trunk stability exercise using proprioceptive neuromuscular facilitation with different chair heights (50, 60, and 70 cm). These exercises were performed 5 times per week for 6 weeks. Gait velocity, cadence, stride length, gait cycle, and stance phase duration were used to measure gait function. [Results] Significant changes in gait velocity, cadence, and stride length were observed on the affected side. However, no significant changes in gait cycle and stance phase were observed on the affected side. [Conclusion] These results indicate that trunk stability exercise using proprioceptive neuromuscular facilitation with change in chair heights were effective in improving gait velocity, cadence, and stride length on the affected side. However, in this study, no significant changes were observed in gait cycle and stance phase on the affected side. Therefore, various interventions for stroke patients should be investigated in further studies.

  5. Proprioceptive deficit in individuals with unilateral tearing of the anterior cruciate ligament after active evaluation of the sense of joint position☆☆☆

    PubMed Central

    Cossich, Victor; Mallrich, Frédéric; Titonelli, Victor; de Sousa, Eduardo Branco; Velasques, Bruna; Salles, José Inácio

    2014-01-01

    Objective To ascertain whether the proprioceptive deficit in the sense of joint position continues to be present when patients with a limb presenting a deficient anterior cruciate ligament (ACL) are assessed by testing their active reproduction of joint position, in comparison with the contralateral limb. Methods Twenty patients with unilateral ACL tearing participated in the study. Their active reproduction of joint position in the limb with the deficient ACL and in the healthy contralateral limb was tested. Meta-positions of 20% and 50% of the maximum joint range of motion were used. Proprioceptive performance was determined through the values of the absolute error, variable error and constant error. Results Significant differences in absolute error were found at both of the positions evaluated, and in constant error at 50% of the maximum joint range of motion. Conclusion When evaluated in terms of absolute error, the proprioceptive deficit continues to be present even when an active evaluation of the sense of joint position is made. Consequently, this sense involves activity of both intramuscular and tendon receptors. PMID:26229869

  6. Effects of trunk stability exercise using proprioceptive neuromuscular facilitation with changes in chair height on the gait of patients who had a stroke

    PubMed Central

    Park, Si-Eun; Moon, Sang-Hyun

    2016-01-01

    [Purpose] The purpose of this study was to identify the effects of trunk stability exercise using proprioceptive neuromuscular facilitation with changes in chair heights on the gait of stroke patients. [Subjects and Methods] The subjects of this study were 11 stroke patients. The intervention method was trunk stability exercise using proprioceptive neuromuscular facilitation with different chair heights (50, 60, and 70 cm). These exercises were performed 5 times per week for 6 weeks. Gait velocity, cadence, stride length, gait cycle, and stance phase duration were used to measure gait function. [Results] Significant changes in gait velocity, cadence, and stride length were observed on the affected side. However, no significant changes in gait cycle and stance phase were observed on the affected side. [Conclusion] These results indicate that trunk stability exercise using proprioceptive neuromuscular facilitation with change in chair heights were effective in improving gait velocity, cadence, and stride length on the affected side. However, in this study, no significant changes were observed in gait cycle and stance phase on the affected side. Therefore, various interventions for stroke patients should be investigated in further studies. PMID:27512254

  7. Slow Reading: Reading along "Lectio" Lines

    ERIC Educational Resources Information Center

    Badley, K. Jo-Ann; Badley, Ken

    2011-01-01

    The medieval monastic movement preserved and developed reading practices--lectio--from ancient Greek pedagogy as a slow, mindful approach to reading for formation. This ancient way of reading, now better known as lectio divina, challenges the fast, pragmatic reading so characteristic of our time. We propose that the present moment may be ripe for…

  8. Experimental demonstration of spinor slow light

    NASA Astrophysics Data System (ADS)

    Lee, Meng-Jung; Ruseckas, Julius; Lee, Chin-Yuan; Kudriašov, Viačeslav; Chang, Kao-Fang; Cho, Hung-Wen; Juzeliānas, Gediminas; Yu, Ite A.

    2014-11-01

    Slow light based on the effect of electromagnetically induced transparency is of great interest due to its applications in low-light-level nonlinear optics and quantum information manipulation. The previous experiments all dealt with the single-component slow light. Here, we report the experimental demonstration of two-component or spinor slow light using a double-tripod atom-light coupling scheme. The scheme involves three atomic ground states coupled to two excited states by six light fields. The oscillation due to the interaction between the two components was observed. On the basis of the stored light, our data showed that the double-tripod scheme behaves like the two outcomes of an interferometer enabling precision measurements of frequency detuning. We experimentally demonstrated a possible application of the double-tripod scheme as quantum memory/rotator for the two-colour qubit. Our study also suggests that the spinor slow light is a better method than a widely used scheme in the nonlinear frequency conversion.

  9. Retention by "Fast" and "Slow" Learners.

    ERIC Educational Resources Information Center

    Gentile, J. Ronald; And Others

    1982-01-01

    In four experiments to replicate and extend the findings of Shuell and Keppel (EJ 016 150), "fast" and "slow" learners were brought to a similar learning criterion, with the result that their forgetting curves were parallel. The experiments involved American and Nigerian students in learning word lists and poems. (Author/CM)

  10. Slowness tomography of Pdif beneath Western Africa

    NASA Astrophysics Data System (ADS)

    Ivan, Marian; Ghica, Daniela Veronica; Gosar, Andrej; Hatzidimitriou, Panagiotis; Hofstetter, Rami; Polat, Gulten; Wang, Rongjiang

    2014-05-01

    Major earthquakes (M> 6.4) in South America (near Coast of Central Chile) and South Atlantic Ocean (Scotia Sea and Sandwich Islands) routinely display conspicuous Pdif phases as recorded by the Central European and Western Mediterranean seismological networks. The relative arrival times of Pdif at the stations of a certain network are obtained by correlating the individual traces with a template obtained using the corresponding network beam. The slowness values are derived by linear regression together with the 95% errors. A check for the presence of outliers is done using Chauvenet's criterion. Ellipticity corrections are evaluated with the standard tables. Corrections for the diffracted ray path are applied using a global 3-D model and a slightly modified version of the TauP Toolkit. The same procedure is applied to the synthetic seismograms to provide the reference slowness. Using a slowness tomographic approach, the (relative) slowness perturbation values are directly inverted to the velocity perturbations assigned to a set of trapezoidal cells located on the core-mantle boundary (CMB). The above 95% errors are used to weight the inversion, which is solved by a Monte Carlo method. Finally, we compare our results to the P-velocity perturbations from several global 3-D models in the same CMB area beneath Western Africa.

  11. Experimental demonstration of spinor slow light

    PubMed Central

    Lee, Meng-Jung; Ruseckas, Julius; Lee, Chin-Yuan; Kudriašov, Viačeslav; Chang, Kao-Fang; Cho, Hung-Wen; Juzeliānas, Gediminas; Yu, Ite A.

    2014-01-01

    Slow light based on the effect of electromagnetically induced transparency is of great interest due to its applications in low-light-level nonlinear optics and quantum information manipulation. The previous experiments all dealt with the single-component slow light. Here, we report the experimental demonstration of two-component or spinor slow light using a double-tripod atom–light coupling scheme. The scheme involves three atomic ground states coupled to two excited states by six light fields. The oscillation due to the interaction between the two components was observed. On the basis of the stored light, our data showed that the double-tripod scheme behaves like the two outcomes of an interferometer enabling precision measurements of frequency detuning. We experimentally demonstrated a possible application of the double-tripod scheme as quantum memory/rotator for the two-colour qubit. Our study also suggests that the spinor slow light is a better method than a widely used scheme in the nonlinear frequency conversion. PMID:25417851

  12. Slowed ageing, welfare, and population problems.

    PubMed

    Wareham, Christopher

    2015-10-01

    Biological studies have demonstrated that it is possible to slow the ageing process and extend lifespan in a wide variety of organisms, perhaps including humans. Making use of the findings of these studies, this article examines two problems concerning the effect of life extension on population size and welfare. The first--the problem of overpopulation--is that as a result of life extension too many people will co-exist at the same time, resulting in decreases in average welfare. The second--the problem of underpopulation--is that life extension will result in too few people existing across time, resulting in decreases in total welfare. I argue that overpopulation is highly unlikely to result from technologies that slow ageing. Moreover, I claim that the problem of underpopulation relies on claims about life extension that are false in the case of life extension by slowed ageing. The upshot of these arguments is that the population problems discussed provide scant reason to oppose life extension by slowed ageing.

  13. Human Gamma Oscillations during Slow Wave Sleep

    PubMed Central

    Valderrama, Mario; Crépon, Benoît; Botella-Soler, Vicente; Martinerie, Jacques; Hasboun, Dominique; Alvarado-Rojas, Catalina; Baulac, Michel; Adam, Claude; Navarro, Vincent; Le Van Quyen, Michel

    2012-01-01

    Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS). At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30–50 Hz) and high (60–120 Hz) frequency bands recurrently emerged in all investigated regions and their amplitudes coincided with specific phases of the cortical slow wave. In most of the cases, multiple oscillatory bursts in different frequency bands from 30 to 120 Hz were correlated with positive peaks of scalp slow waves (“IN-phase” pattern), confirming previous animal findings. In addition, we report another gamma pattern that appears preferentially during the negative phase of the slow wave (“ANTI-phase” pattern). This new pattern presented dominant peaks in the high gamma range and was preferentially expressed in the temporal cortex. Finally, we found that the spatial coherence between cortical sites exhibiting gamma activities was local and fell off quickly when computed between distant sites. Overall, these results provide the first human evidences that gamma oscillations can be observed in macroscopic EEG recordings during sleep. They support the concept that these high-frequency activities might be associated with phasic increases of neural activity during slow oscillations. Such patterned activity in the sleeping brain could play a role in off-line processing of cortical networks. PMID:22496749

  14. The Contribution of Proprioceptive Information to Postural Control in Elderly and Patients with Parkinson’s Disease with a History of Falls

    PubMed Central

    Bekkers, Esther M. J.; Dockx, Kim; Heremans, Elke; Vercruysse, Sarah; Verschueren, Sabine M. P.; Mirelman, Anat; Nieuwboer, Alice

    2014-01-01

    Proprioceptive deficits negatively affect postural control but their precise contribution to postural instability in Parkinson’s disease (PD) is unclear. We investigated if proprioceptive manipulations differentially affect balance, measured by force plates, during quiet standing in 13 PD patients and 13 age-matched controls with a history of falls. Perceived limits of stability (LoS) were derived from the differences between maximal center of pressure (CoP) displacement in anterior–posterior (AP) and medio-lateral (ML) direction during a maximal leaning task. Task conditions comprised standing with eyes open (EO) and eyes closed (EC): (1) on a stable surface; (2) an unstable surface; and (3) with Achilles tendon vibration. CoP displacements were calculated as a percentage of their respective LoS. Perceived LoS did not differ between groups. PD patients showed greater ML CoP displacement than elderly fallers (EF) across all conditions (p = 0.043) and tended to have higher postural sway in relation to the LoS (p = 0.050). Both groups performed worse on an unstable surface and during tendon vibration compared to standing on a stable surface with EO and even more so with EC. Both PD and EF had more AP sway in all conditions with EC compared to EO (p < 0.001) and showed increased CoP displacements when relying on proprioception only compared to standing with normal sensory input. This implies a similar role of the proprioceptive system in postural control in fallers with and without PD. PD fallers showed higher ML sway after sensory manipulations, as a result of which these values approached their perceived LoS more closely than in EF. We conclude that despite a similar fall history, PD patients showed more ML instability than EF, irrespective of sensory manipulation, but had a similar reliance on ankle proprioception. Hence, we recommend that rehabilitation and fall prevention for PD should focus on motor rather than on sensory aspects. PMID:25505395

  15. Slowing and cooling atoms in isotropic laser light

    NASA Astrophysics Data System (ADS)

    Ketterle, Wolfgang; Martin, Alex; Joffe, Michael A.; Pritchard, David E.

    1992-10-01

    We demonstrate cooling and slowing of atoms in isotropic laser light. As the atoms slow, they compensate for their changing Doppler shift by preferentially absorbing photons at a varying angle to their direction of motion, resulting in a continuous beam of slow atoms unperturbed by an intense slowing laser beam. We point out several novel features of slowing and cooling in isotropic light, and show that it can be superior to cooling with directed laser beams.

  16. Effect of eye movements and proprioceptive neuromuscular facilitation on balance and head alignment in stroke patients with neglect syndrome.

    PubMed

    Park, Si-Eun; Min, Kyung-Ok; Lee, Sang-Bin; Choi, Wan-Suk; Kim, Soon-Hee

    2016-01-01

    [Purpose] The purpose of this study was to assess the effect of eye movements and proprioceptive neuromuscular facilitation (PNF) on patients with neglect syndrome. [Subjects and Methods] The subjects were randomly allocated to 2 groups: the eye movements (EM) group; and the PNF with eye movements (PEM) group. The program was conducted five times each week for 6 weeks. Balance (both static and dynamic) and head alignment (craniovertebral angle and cranial rotation angle) were measured before and after testing. [Results] In measurements of static balance, the EM group showed significant improvement in sway length and sway area when examined in the eyes-open condition, but not when examined in the eyes-closed condition. The PEM group showed significant improvement when examined under both conditions. In the assessment of dynamic balance, both groups showed significant improvement in measurements of sway areas. With respect to head alignment, there were no significant differences pre- and post-testing in either the craniovertebral angle or the cranial rotation angle in the EM group, but the PEM group showed significant differences in both measurements. [Conclusion] These results suggest that in stroke patients with neglect syndrome, PNF with eye movements, rather than eye movements alone, has a greater positive effect on balance and head alignment.

  17. The development of system components to provide proprioceptive and tactile information to the human for future telepresence systems

    NASA Technical Reports Server (NTRS)

    Wright, Ammon K.

    1992-01-01

    System components are presented that are being implemented to augment teleoperated systems by providing both force and tactile information to the human operator. The concept proposed is the control of a manipulator to perform tasks; i.e., flight line maintenance and repair of combat aircraft or satellites while under the control of a human operator at a remote location to maintain mission effectiveness in a hostile environment. The human would control the motion of the manipulator via a master system with information from the remote site being fed back by direct stimulation of the humans sensory mechanisms or by graphic interpretation of displays. We are interested in providing the operator feedback of position, force, auditory, vision, and tactile information to aide in the human's cognitive ability to control the manipulator. This sensory information from the remote site would then be presented to the operator in such a manner as to enhance his performance while providing him a sense of being present at the remote location, this is known as telepresence. Also discussed is the research done by the Human Sensory Feedback (HSF) facility at the Armstrong Laboratory to provide tactile and proprioceptive feedback to the operator. The system components of this system includes tactile sensor and stimulators, dexterous robotic hands, and the control of positioning and operating industrial robots with exoskeletal mechanisms.

  18. Effect of proprioceptive neuromuscular facilitation D2 flexion and breathing exercises on lymphedema without a short stretch compression bandage.

    PubMed

    Hwang, Woon Taek; Chung, Sin Ho; Chung, Min Sung; Lee, Kyu Hoon; Kim, Taikon

    2015-10-01

    [Purpose] The aim of this study was to evaluate the effects of proprioceptive neuromuscular facilitation (PNF) D2 flexion and breathing exercises in a patient with lymphedema (LE). [Subject] This report describes a 57-year-old woman with LE in whom a short-stretch compression bandage (SSCB) could not be used for treatment because of skin itching and redness. [Methods] The patient received complex decongestive therapy without a SSCB. Next, PNF D2 flexion and breathing exercises were conducted three times per week for 14 weeks (36 times). [Results] As a result, the circumference of the armpit was reduced by 0.5 cm; that of 10 cm above the elbow, by 1 cm; that of the elbow, by 0.5 cm; that of 10 cm below the elbow, by 1 cm; and that of the back of the hand, by 0.5 cm. A total of 100 mL (9.4%) of body water was eliminated from the right upper extremity, and moisture ratio was reduced by 0.005%. Finally, range of motion was improved to 20° flexion, 60° abduction, 40° external rotation, and 10° internal rotation. [Conclusion] This study showed that PNF D2 flexion and breathing exercises were effective in reducing LE and improving range of motion. PMID:26644706

  19. Applying proprioceptive neuromuscular facilitation stretching: optimal contraction intensity to attain the maximum increase in range of motion in young males

    PubMed Central

    Kwak, Dong Ho; Ryu, Young Uk

    2015-01-01

    [Purpose] Proprioceptive neuromuscular facilitation (PNF) stretching is known to be effective in increasing joint ROM. The PNF stretching technique first induces an isometric contraction in the muscles to be stretched, but no agreement concerning the optimal contraction intensity has yet been reached. The purpose of the present study was to examine the effect of contraction intensity on ROM while applying PNF stretching. [Subjects and Methods] Sixty male subjects were randomly assigned to one of four groups (three experimental groups and one control group). Each experimental group applied one of three contraction intensities (100%, 60%, and 20%) defined by the MVIC ratio, and the control group did not receive any intervention during the experiment. PNF stretching was applied to left knee extensors to compare changes in the knee joint flexion angle. [Results] The results showed that the changes in ROM were larger for the 60% and 100% groups compared with the 20% group. The changes in ROM were lowest in the control group. [Conclusion] The present results indicate that while applying the PNF stretching, it is not necessary to apply the maximum intensity of muscle contraction. Moderate isometric contraction intensities may be optimal for healthy young males, while a sufficient effect can be obtained even with a low contraction intensity. PMID:26310658

  20. Immediate effect of static and proprioceptive neuromuscular facilitation stretching on hip adductor flexibility in female ballet dancers.

    PubMed

    Rubini, Ercole C; Souza, Andréa C; Mello, Mônica L; Bacurau, Reury F P; Cabral, Leonardo F; Farinatti, Paulo T V

    2011-01-01

    The aim of the present study was to investigate the immediate effects of static and proprioceptive neuromuscular facilitation (PNF) stretching on the flexibility of hip adductors in female ballet dancers. Forty-five subjects (age: 28.5 ± 8.0 years; minimum two years of ballet training) were randomly assigned to three groups: PNF (contract-release technique), Static, and Control. Subjects in the PNF and Static groups performed four sets of 30 second stretching with an interval of 30 seconds between sets. The control group stayed at rest for the same time spent by the PNF and Static groups during the stretching sessions. Maximal range of motion was measured before and immediately after the experimental and control protocols in all groups. The results indicated significant differences between pre- and post-stretching flexibility in both PNF and Static groups (p < 0.0001; effect size = 0.24 and 0.39, respectively), whereas no change was identified in the Control group (p = 0.265). However, no differences in post-exercise flexibility were found between PNF and Static groups (p = 0.235). It is concluded that static and PNF stretching methods provoked similar post-exercise acute effects on the maximal range of motion of hip adductors in highly flexible female ballet dancers.

  1. Persistent effects after trigeminal nerve proprioceptive stimulation by mandibular extension on rat blood pressure, heart rate and pial microcirculation.

    PubMed

    Lapi, D; Colantuoni, A; Del Seppia, C; Ghione, S; Tonlorenzi, D; Brunelli, M; Scuri, R

    2013-03-01

    The trigemino-cardiac reflex is a brainstem reflex known to lead to a decrement in heart rate and blood pressure, whereas few data have been collected about its effects on the cerebral hemodynamic. In this study we assess the in vivo effects of trigeminal nerve peripheral stimulation by mandibular extension on pial microcirculation and systemic arterial blood pressure in rats. Experiments were performed in male Wistar rats subjected to mandibular extension obtained inserting an ad hoc developed retractor between the dental arches. Mean arterial blood pressure and heart rate were recorded and the pial arterioles were visualized by fluorescence microscopy to measure the vessel diameters before (15 minutes) during (5-15 minutes) and after (80 minutes) mandibular extension. While in control rats (sham-operated rats) and in rats subjected to the dissection of the trigeminal peripheral branches mean arterial blood pressure, heart rate and pial microcirculation did not change during the whole observation period (110 minutes), in rats submitted to mandibular extension, mean arterial blood pressure, heart rate and arteriolar diameter significantly decreased during stimulation. Afterward mean arterial blood pressure remained reduced as well as heart rate, while arteriolar diameter significantly increased evidencing a vasodilatation persisting for the whole remaining observation time. Therefore, trigeminal nerve proprioceptive stimulation appears to trigger specific mechanisms regulating systemic arterial blood pressure and pial microcirculation.

  2. Effects of oculo-motor exercise, functional electrical stimulation and proprioceptive neuromuscular stimulation on visual perception of spatial neglect patients

    PubMed Central

    Park, Si-Eun; Oh, Dae-Sik; Moon, Sang-Hyun

    2016-01-01

    [Purpose] The purpose of this study was to identify the effects of oculo-motor exercise, functional electrical stimulation (FES), and proprioceptive neuromuscular facilitation (PNF) on the visual perception of spatial neglect patients. [Subjects and Methods] The subjects were randomly allocated to 3 groups: an oculo-motor exercise (OME) group, a FES with oculo-motor exercise (FOME) group, and a PNF with oculo-motor exercise (POME) group. The line bisection test (LBT), motor free visual test (MVPT), and Catherine Bergego Scale (CBS) were used to measure visual perception. These were performed 5 times per week for 6 weeks. [Results] The OME group and POME group showed significant improvements according to the LBT and MVPT results, but the FOME group showed no significant improvement. According to the CBS, all 3 groups showed significant improvements. The OME and POME groups showed improvement over the FOME group in the LBT and MVPT. However, there was no significant difference among the three groups according to the CBS. [Conclusion] These results indicate that oculo-motor exercise and PNF with oculo-motor exercise had more positive effects than FES with oculo-motor exercise on the visual perception of spatial neglect patients. PMID:27190436

  3. Removal of proprioception by BCI raises a stronger body ownership illusion in control of a humanlike robot

    PubMed Central

    Alimardani, Maryam; Nishio, Shuichi; Ishiguro, Hiroshi

    2016-01-01

    Body ownership illusions provide evidence that our sense of self is not coherent and can be extended to non-body objects. Studying about these illusions gives us practical tools to understand the brain mechanisms that underlie body recognition and the experience of self. We previously introduced an illusion of body ownership transfer (BOT) for operators of a very humanlike robot. This sensation of owning the robot’s body was confirmed when operators controlled the robot either by performing the desired motion with their body (motion-control) or by employing a brain-computer interface (BCI) that translated motor imagery commands to robot movement (BCI-control). The interesting observation during BCI-control was that the illusion could be induced even with a noticeable delay in the BCI system. Temporal discrepancy has always shown critical weakening effects on body ownership illusions. However the delay-robustness of BOT during BCI-control raised a question about the interaction between the proprioceptive inputs and delayed visual feedback in agency-driven illusions. In this work, we compared the intensity of BOT illusion for operators in two conditions; motion-control and BCI-control. Our results revealed a significantly stronger BOT illusion for the case of BCI-control. This finding highlights BCI’s potential in inducing stronger agency-driven illusions by building a direct communication between the brain and controlled body, and therefore removing awareness from the subject’s own body. PMID:27654174

  4. Effects of Proprioceptive Neuromuscular Facilitation Stretching and Kinesiology Taping on Pelvic Compensation During Double-Knee Extension

    PubMed Central

    Lee, Seung-Woong; Lee, Jung-Hoon

    2015-01-01

    Shortened hamstrings are likely to restrict the anterior pelvic tilt and induce a slumped posture due to the posterior pelvic tilt. This study was conducted to compare the effects of proprioceptive neuromuscular facilitation (PNF) stretching and modified anterior pelvic tilt taping (APTT) on hamstring shortness-associated pelvic compensation while executing seated double-knee extension. Male college students (28 healthy young adults; mean age: 21.4 ± 2.1 years) with hamstring shortness were recruited as study subjects and randomly assigned to either the PNF stretching group (control group) or the APTT group (experimental group). In all the subjects, changes in the movement distance of the centre of gluteal pressure (COGP) as well as rectus abdominis (RA) and semitendinosus (SEM) muscle activities were measured during seated double-knee extension while the respective intervention method was applied. Both groups showed significant decreases in COGP distance and RA muscle activity compared with their respective baseline values (p < 0.05), however, no significant changes were observed in SEM muscle activity. We can infer that not only a direct intervention on the hamstring, such as PNF stretching, but also a modified APTT-mediated pelvic intervention may be used as a method for reducing pelvic compensation induced by hamstring shortness. PMID:26839606

  5. Effects of oculo-motor exercise, functional electrical stimulation and proprioceptive neuromuscular stimulation on visual perception of spatial neglect patients.

    PubMed

    Park, Si-Eun; Oh, Dae-Sik; Moon, Sang-Hyun

    2016-04-01

    [Purpose] The purpose of this study was to identify the effects of oculo-motor exercise, functional electrical stimulation (FES), and proprioceptive neuromuscular facilitation (PNF) on the visual perception of spatial neglect patients. [Subjects and Methods] The subjects were randomly allocated to 3 groups: an oculo-motor exercise (OME) group, a FES with oculo-motor exercise (FOME) group, and a PNF with oculo-motor exercise (POME) group. The line bisection test (LBT), motor free visual test (MVPT), and Catherine Bergego Scale (CBS) were used to measure visual perception. These were performed 5 times per week for 6 weeks. [Results] The OME group and POME group showed significant improvements according to the LBT and MVPT results, but the FOME group showed no significant improvement. According to the CBS, all 3 groups showed significant improvements. The OME and POME groups showed improvement over the FOME group in the LBT and MVPT. However, there was no significant difference among the three groups according to the CBS. [Conclusion] These results indicate that oculo-motor exercise and PNF with oculo-motor exercise had more positive effects than FES with oculo-motor exercise on the visual perception of spatial neglect patients.

  6. Effect of eye movements and proprioceptive neuromuscular facilitation on balance and head alignment in stroke patients with neglect syndrome

    PubMed Central

    Park, Si-Eun; Min, Kyung-Ok; Lee, Sang-Bin; Choi, Wan-Suk; Kim, Soon-Hee

    2016-01-01

    [Purpose] The purpose of this study was to assess the effect of eye movements and proprioceptive neuromuscular facilitation (PNF) on patients with neglect syndrome. [Subjects and Methods] The subjects were randomly allocated to 2 groups: the eye movements (EM) group; and the PNF with eye movements (PEM) group. The program was conducted five times each week for 6 weeks. Balance (both static and dynamic) and head alignment (craniovertebral angle and cranial rotation angle) were measured before and after testing. [Results] In measurements of static balance, the EM group showed significant improvement in sway length and sway area when examined in the eyes-open condition, but not when examined in the eyes-closed condition. The PEM group showed significant improvement when examined under both conditions. In the assessment of dynamic balance, both groups showed significant improvement in measurements of sway areas. With respect to head alignment, there were no significant differences pre- and post-testing in either the craniovertebral angle or the cranial rotation angle in the EM group, but the PEM group showed significant differences in both measurements. [Conclusion] These results suggest that in stroke patients with neglect syndrome, PNF with eye movements, rather than eye movements alone, has a greater positive effect on balance and head alignment. PMID:27065550

  7. Effects of Proprioceptive Neuromuscular Facilitation Stretching and Kinesiology Taping on Pelvic Compensation During Double-Knee Extension.

    PubMed

    Lee, Seung-Woong; Lee, Jung-Hoon

    2015-12-22

    Shortened hamstrings are likely to restrict the anterior pelvic tilt and induce a slumped posture due to the posterior pelvic tilt. This study was conducted to compare the effects of proprioceptive neuromuscular facilitation (PNF) stretching and modified anterior pelvic tilt taping (APTT) on hamstring shortness-associated pelvic compensation while executing seated double-knee extension. Male college students (28 healthy young adults; mean age: 21.4 ± 2.1 years) with hamstring shortness were recruited as study subjects and randomly assigned to either the PNF stretching group (control group) or the APTT group (experimental group). In all the subjects, changes in the movement distance of the centre of gluteal pressure (COGP) as well as rectus abdominis (RA) and semitendinosus (SEM) muscle activities were measured during seated double-knee extension while the respective intervention method was applied. Both groups showed significant decreases in COGP distance and RA muscle activity compared with their respective baseline values (p < 0.05), however, no significant changes were observed in SEM muscle activity. We can infer that not only a direct intervention on the hamstring, such as PNF stretching, but also a modified APTT-mediated pelvic intervention may be used as a method for reducing pelvic compensation induced by hamstring shortness.

  8. Slow Microbial Life in the Seabed

    NASA Astrophysics Data System (ADS)

    Jørgensen, Bo Barker; Marshall, Ian P. G.

    2016-01-01

    Global microbial cell numbers in the seabed exceed those in the overlying water column, yet these organisms receive less than 1% of the energy fixed as organic matter in the ocean. The microorganisms of this marine deep biosphere subsist as stable and diverse communities with extremely low energy availability. Growth is exceedingly slow, possibly regulated by virus-induced mortality, and the mean generation times are tens to thousands of years. Intermediate substrates such as acetate are maintained at low micromolar concentrations, yet their turnover time may be several hundred years. Owing to slow growth, a cell community may go through only 10,000 generations from the time it is buried beneath the mixed surface layer until it reaches a depth of tens of meters several million years later. We discuss the efficiency of the energy-conserving machinery of subsurface microorganisms and how they may minimize energy consumption through necessary maintenance, repair, and growth.

  9. Quake clamps down on slow slip

    NASA Astrophysics Data System (ADS)

    Wallace, Laura M.; Bartlow, Noel; Hamling, Ian; Fry, Bill

    2014-12-01

    Using continuous GPS (cGPS) data from the Hikurangi subduction zone in New Zealand, we show for the first time that stress changes induced by a local earthquake can arrest an ongoing slow slip event (SSE). The cGPS data show that the slip rate in the northern portion of the 2013/2014 Kapiti SSE decreased abruptly following a nearby intraslab earthquake. We suggest that deceleration of the Kapiti SSE in early 2014 occurred due to a tenfold increase in the normal stress relative to shear stress in the SSE source, induced by the nearby Mw 6.3 earthquake, consistent with expectations of rate and state friction. Our observation of an abrupt halting/slowing of the SSE in response to stress changes imposed by a local earthquake has implications for the strength of fault zones hosting SSEs and supports the premise that static stress changes are an important ingredient in triggering (or delaying) fault slip.

  10. Motor slowing in asymptomatic HIV infection.

    PubMed

    Fitzgibbon, M L; Cella, D F; Humfleet, G; Griffin, E; Sheridan, K

    1989-06-01

    To examine neuropsychological deficits associated with the human immunodeficiency virus (HIV), 25 asymptomatic homosexual men and sexual partners of intravenous drug users and 25 seronegative homosexual men and nonhigh-risk heterosexuals were assessed on measures of fine motor control, visual scanning, attention, depression, and global psychological functioning. Analysis suggested that HIV infection is associated with reduced fine motor control. Seropositivity is associated with elevated depression and global psychological maladjustment. When depression and global adjustment were analyzed as covariates, motor slowing was evident in the seropositive group. These findings suggest an association between motor slowing and HIV infection in asymptomatic subjects and point to the necessity of measuring affect at least as a control variable. Further study is needed to determine whether the fine motor deficit evident in this sample is limited to distinct subgrouping of the over-all sample. PMID:2762096

  11. Critical slowing down in a dynamic duopoly

    NASA Astrophysics Data System (ADS)

    Escobido, M. G. O.; Hatano, N.

    2015-01-01

    Anticipating critical transitions is very important in economic systems as it can mean survival or demise of firms under stressful competition. As such identifying indicators that can provide early warning to these transitions are very crucial. In other complex systems, critical slowing down has been shown to anticipate critical transitions. In this paper, we investigate the applicability of the concept in the heterogeneous quantity competition between two firms. We develop a dynamic model where the duopoly can adjust their production in a logistic process. We show that the resulting dynamics is formally equivalent to a competitive Lotka-Volterra system. We investigate the behavior of the dominant eigenvalues and identify conditions that critical slowing down can provide early warning to the critical transitions in the dynamic duopoly.

  12. Is slow slip in Cascadia tidally modulated?

    NASA Astrophysics Data System (ADS)

    Hawthorne, J. C.; Rubin, A. M.

    2009-12-01

    Several studies have shown that the seismic tremor in episodic tremor and slip is tidally modulated, suggesting a strong sensitivity to the rather small tidal stresses. We address whether the slip is also tidally modulated by examining data from six borehole strainmeters in northwest Washington and southern Vancouver Island. We use the processed data provided by Plate Boundary Observatory (PBO), which is resampled to 5-minute intervals. However, we recompute empirical corrections for tides, a long-term linear trend, and barometric pressure in the 50 days surrounding each slow slip event. We then fit sinusoids at the tidal periods to the processed data as proxies for the tidally modulated component of slip, along with a linear trend as a proxy for the net strain in the slow slip. The data are too noisy to allow detection any tidal modulation using only a single event and station. We therefore simultaneously fit data from multiple stations and from three slow slip events since 2007. This assumes that the phase of the tides at the slipping regions detected by all stations is the same and that the phase of the fault response to the tidal stress is constant. Combining the stations and events both reduces the noise at the tidal periods and creates a longer time series, which allows us to separate energy at the different tidal frequencies. We find significant tidal signals at the 12.4 and 25.8-hour periods which differ from zero at the 1.5 to 2-sigma level. Errors are estimated by bootstrapping the slow slip strain and by considering the tidal signal at times before the slow slip event. The 12.4 and 25.8-hour sinusoids have amplitudes of 23 (10-40 at 2-sigma) and 15 (0-30 at 2-sigma) percent of the maximum amplitude that does not allow the slow slip strain signal to change sign, where the mean strain rate is estimated from the linear trends fit to the slow slip data. In terms of slip rate, the sinusoids at each period could then modulate the slip rate 23 and 15 percent

  13. Slow microwaves in left-handed materials

    NASA Astrophysics Data System (ADS)

    di Gennaro, E.; Parimi, P. V.; Lu, W. T.; Sridhar, S.; Derov, J. S.; Turchinetz, B.

    2005-07-01

    Remarkably slow propagation of microwaves in two different classes of left-handed materials (LHM’s) is reported from microwave-pulse and continuous-wave transmission measurements. Microwave dispersion in a composite LHM made of split-ring resonators and wire strips reveals group velocity vg˜c/50 , where c is the free-space light velocity. Photonic crystals (PhC’s) made of dielectric Al2O3 rods reveal vg˜c/10 . Group delay dispersion of both the composite LHM and PhC’s determined from the experiment is in complete agreement with that obtained from theory. The slow group velocities are quantitatively described by the strong dispersion observed in these materials.

  14. Slow light in liquid crystal media

    NASA Astrophysics Data System (ADS)

    Bortolozzo, Umberto; Wei, Dong; Huignard, Jean-Pierre; Residori, Stefania

    2014-10-01

    Liquid crystal media are characterized by large and tunable dispersive properties and hence allow achievement of large group delays. At the same time, liquid crystals provide large areas and are easily reconfigurable and highly sensitive devices; they are, therefore, well adapted for interferometric applications. Two different ways of achieving slow light in liquid crystals are presented. The first method consists of exploiting photoisomerization-induced transparency in dye-doped chiral liquid crystals, and the second method makes use of two-wave mixing optical resonance in pure nematics. In both mechanisms, two beams are sent to the medium, where they create a grating, either of absorption or of refractive index. Both physical mechanisms are elucidated in the context of slow light, then, as examples of sensing applications, Doppler shift measurements and adaptive holography are presented.

  15. Techniques for slow cryopreservation of embryos.

    PubMed

    Gosden, Lucinda Veeck

    2014-01-01

    The slow cryopreservation of embryos has been used for nearly three decades as a means of storing surplus conceptuses from single IVF (in vitro fertilization) cycles. Doing so has allowed caregivers to maximize pregnancy rates without wastage of precious biological materials. Very detailed methods are described here using a popular biological freezing unit manufactured by Planer PLC (Middlesex, UK). Culture media preparation and tranfer protocols, including replacement in both natural and stimulated cycles, are included. PMID:24782021

  16. Method for monitoring slow dynamics recovery

    NASA Astrophysics Data System (ADS)

    Haller, Kristian C. E.; Hedberg, Claes M.

    2012-11-01

    Slow Dynamics is a specific material property, which for example is connected to the degree of damage. It is therefore of importance to be able to attain proper measurements of it. Usually it has been monitored by acoustic resonance methods which have very high sensitivity as such. However, because the acoustic wave is acting both as conditioner and as probe, the measurement is affecting the result which leads to a mixing of the fast nonlinear response to the excitation and the slow dynamics material recovery. In this article a method is introduced which, for the first time, removes the fast dynamics from the process and allows the behavior of the slow dynamics to be monitored by itself. The new method has the ability to measure at the shortest possible recovery times, and at very small conditioning strains. For the lowest strains the sound speed increases with strain, while at higher strains a linear decreasing dependence is observed. This is the first method and test that has been able to monitor the true material state recovery process.

  17. Single-electron tunneling with slow insulators

    NASA Astrophysics Data System (ADS)

    Fedorov, S. A.; Chtchelkatchev, N. M.; Udalov, O. G.; Beloborodov, I. S.

    2015-09-01

    The usual paradigm in the theory of electron transport is related to the fact that the dielectric permittivity of the insulator is assumed to be constant, with no time dispersion. We take into account the "slow" polarization dynamics of the dielectric layers in the tunnel barriers in the fluctuating electric fields induced by single-electron tunneling events and study transport in the single-electron transistor (SET). Here "slow" dielectric implies a time scale that is slow compared to the characteristic time scales of the SET charging-discharging effects. We show that for strong enough polarizability, such that the induced charge on the island is comparable to the elementary charge, the transport properties of the SET substantially deviate from the known results of transport theory of the SET. In particular, the Coulomb blockade is more pronounced at finite temperature, the conductance peaks change their shape, and the current-voltage characteristics show the memory effect (hysteresis). However, in contrast to SETs with ferroelectric tunnel junctions, here the periodicity of the conductance in the gate voltage is not broken; instead, the period strongly depends on the polarizability of the gate dielectric. We uncover the fine structure of the hysteresis effect where the "large" hysteresis loop may include a number of "smaller" loops. Also we predict the memory effect in the current-voltage characteristics I (V ) , with I (V )≠-I (-V ) .

  18. The Magnetic Topology of Slow Wind Sources

    NASA Astrophysics Data System (ADS)

    Antiochos, S. K.

    2012-12-01

    Due to its observed location in the heliosphere, plasma composition, and variability, most models for the origins of the slow wind postulate that it is a result of the release of closed-field plasma onto open field lines. In particular, in the S-Web model the slow wind originates at a dynamic boundary region between open and closed flux in the solar corona. Consequently, the detailed topology of the open-closed magnetic boundary is critically important for determining the properties of the slow wind. We discuss the possible magnetic topologies for the open-closed boundary. There are three main topologies corresponding to three types of observed coronal structures: helmet streamers, plumes/coronal jets, and plasma sheets (also known as pseudostreamers). I present models for each of these topologies and show that each is very different at the Sun. I also argue that each will have very different consequences for the observed properties of the wind in the heliosphere. This work was funded in part by the NASA TR&T and SR&T Programs.

  19. Nonlinear dynamical triggering of slow slip

    SciTech Connect

    Johnson, Paul A; Knuth, Matthew W; Kaproth, Bryan M; Carpenter, Brett; Guyer, Robert A; Le Bas, Pierre - Yves; Daub, Eric G; Marone, Chris

    2010-12-10

    Among the most fascinating, recent discoveries in seismology have been the phenomena of triggered slip, including triggered earthquakes and triggered-tremor, as well as triggered slow, silent-slip during which no seismic energy is radiated. Because fault nucleation depths cannot be probed directly, the physical regimes in which these phenomena occur are poorly understood. Thus determining physical properties that control diverse types of triggered fault sliding and what frictional constitutive laws govern triggered faulting variability is challenging. We are characterizing the physical controls of triggered faulting with the goal of developing constitutive relations by conducting laboratory and numerical modeling experiments in sheared granular media at varying load conditions. In order to simulate granular fault zone gouge in the laboratory, glass beads are sheared in a double-direct configuration under constant normal stress, while subject to transient perturbation by acoustic waves. We find that triggered, slow, silent-slip occurs at very small confining loads ({approx}1-3 MPa) that are smaller than those where dynamic earthquake triggering takes place (4-7 MPa), and that triggered slow-slip is associated with bursts of LFE-like acoustic emission. Experimental evidence suggests that the nonlinear dynamical response of the gouge material induced by dynamic waves may be responsible for the triggered slip behavior: the slip-duration, stress-drop and along-strike slip displacement are proportional to the triggering wave amplitude. Further, we observe a shear-modulus decrease corresponding to dynamic-wave triggering relative to the shear modulus of stick-slips. Modulus decrease in response to dynamical wave amplitudes of roughly a microstrain and above is a hallmark of elastic nonlinear behavior. We believe that the dynamical waves increase the material non-affine elastic deformation during shearing, simultaneously leading to instability and slow-slip. The inferred

  20. Slow Wave Sleep and Long Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Whitmire, Alexandra; Orr, Martin; Arias, Diana; Rueger, Melanie; Johnston, Smith; Leveton, Lauren

    2012-01-01

    While ground research has clearly shown that preserving adequate quantities of sleep is essential for optimal health and performance, changes in the progression, order and /or duration of specific stages of sleep is also associated with deleterious outcomes. As seen in Figure 1, in healthy individuals, REM and Non-REM sleep alternate cyclically, with stages of Non-REM sleep structured chronologically. In the early parts of the night, for instance, Non-REM stages 3 and 4 (Slow Wave Sleep, or SWS) last longer while REM sleep spans shorter; as night progresses, the length of SWS is reduced as REM sleep lengthens. This process allows for SWS to establish precedence , with increases in SWS seen when recovering from sleep deprivation. SWS is indeed regarded as the most restorative portion of sleep. During SWS, physiological activities such as hormone secretion, muscle recovery, and immune responses are underway, while neurological processes required for long term learning and memory consolidation, also occur. The structure and duration of specific sleep stages may vary independent of total sleep duration, and changes in the structure and duration have been shown to be associated with deleterious outcomes. Individuals with narcolepsy enter sleep through REM as opposed to stage 1 of NREM. Disrupting slow wave sleep for several consecutive nights without reducing total sleep duration or sleep efficiency is associated with decreased pain threshold, increased discomfort, fatigue, and the inflammatory flare response in skin. Depression has been shown to be associated with a reduction of slow wave sleep and increased REM sleep. Given research that shows deleterious outcomes are associated with changes in sleep structure, it is essential to characterize and mitigate not only total sleep duration, but also changes in sleep stages.

  1. Detecting slow moving targets in SAR images

    NASA Astrophysics Data System (ADS)

    Linnehan, Robert; Perlovsky, Leonid; Mutz, Chris W.; Schindler, John

    2004-08-01

    Ground moving target indication (GMTI) radars can detect slow-moving targets if their velocities are high enough to produce distinguishable Doppler frequencies. However, no reliable technique is currently available to detect targets that fall below the minimum detectable velocity (MDV) of GMTI radars. In synthetic aperture radar (SAR) images, detection of moving targets is difficult because of target smear due to motion, which could make low-RCS targets fall below stationary ground clutter. Several techniques for SAR imaging of moving targets have been discussed in the literature. These techniques require sufficient signal-to-clutter ratio (SCR) and adequate MDV for pre-detection. Other techniques require complex changes in hardware. Extracting the maximum information from SAR image data is possible using adaptive, model-based approaches. However, these approaches lead to computational complexity, which exceeds current processing power for more than a single object in an image. This combinatorial complexity is due to the need for having to consider a large number of combinations between multiple target models and the data, while estimating unknown parameters of the target models. We are developing a technique for detecting slow-moving targets in SAR images with low signal-to-clutter ratio, without minimal velocity requirements, and without combinatorial complexity. This paper briefly summarizes the difficulties related to current model-based detection algorithms. A new concept, dynamic logic, is introduced along with an algorithm suitable for the detection of very slow-moving targets in SAR images. This new mathematical technique is inspired by the analysis of biological systems, like the human brain, which combines conceptual understanding with emotional evaluation and overcomes the combinatorial complexity of model-based techniques.

  2. Counting graphene layers with very slow electrons

    SciTech Connect

    Frank, Ludĕk; Mikmeková, Eliška; Müllerová, Ilona; Lejeune, Michaël

    2015-01-05

    The study aimed at collection of data regarding the transmissivity of freestanding graphene for electrons across their full energy scale down to the lowest energies. Here, we show that the electron transmissivity of graphene drops with the decreasing energy of the electrons and remains below 10% for energies below 30 eV, and that the slow electron transmissivity value is suitable for reliable determination of the number of graphene layers. Moreover, electrons incident below 50 eV release adsorbed hydrocarbon molecules and effectively clean graphene in contrast to faster electrons that decompose these molecules and create carbonaceous contamination.

  3. Slow atom scattering from magnetic media

    NASA Astrophysics Data System (ADS)

    Roach, Timothy; Candee, Katelyn; Moran, Kevin; Richardson, Craig

    2013-05-01

    The use of magnetic field gradients to manipulate atomic motion has a long history, using a variety of field sources: permanent- and electro-magnet, time- and space-dependent, on macro- and micro-scopic scales. We use a curved sub-micron patterned permanent magnet made from recording media to scatter slow atoms arriving at near normal incidence. The atomic waves are expected to be both diffracted and focused. A cloud of Rb atoms from a MOT is released to fall ~10cm to the magnetic surface and the atoms are probed with laser light after the interaction. Preliminary measurements of the scattered atoms will be presented.

  4. Slow Wave Sleep and Long Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Orr, M.; Whitmire, A.; Arias, D.; Leveton, L.

    2011-01-01

    To review the literature on slow wave sleep (SWS) in long duration space flight, and place this within the context of the broader literature on SWS particularly with respect to analogous environments such as the Antarctic. Explore how SWS could be measured within the International Space Station (ISS) context with the aim to utilize the ISS as an analog for future extra-orbital long duration missions. Discuss the potential use of emergent minimally intrusive wireless technologies like ZEO for integrated prelaunch, flight, and return to Earth analysis and optimization of SWS (and general quality of sleep).

  5. Slow-wave electron cyclotron maser

    SciTech Connect

    Kho, T.H.; Lin, A.T.

    1988-09-15

    The basic physics of a slow-wave electron cyclotron maser (ECM) operating in the Cherenkov regime is considered. This device has the advantage over fast-wave ECM's in that it can be operated with direct axial injection of the electron beam, thus allowing for better control over beam quality and a potentially more compact design. The nonlinear evolution and saturation of the instability are studied using computer simulation. It is shown that high efficiency is attainable and, furthermore, that beam momentum spread is better tolerated in the Doppler-shift-dominated regime than is the case for a fast-wave ECM.

  6. Improvement of pedestrian flow by slow rhythm

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Daichi; Tomoeda, Akiyasu; Nishinari, Katsuhiro

    2012-01-01

    We have developed a simple model for pedestrians by dividing walking velocity into two parts, which are step size and pace of walking (number of steps per unit time). Theoretical analysis on pace indicates that rhythm that is slower than normal-walking pace in a low-density regime increases flow if the flow-density diagram is convex downward in a high-density regime. In order to verify this result, we have performed an experiment with real pedestrians and observed the improvement of flow in a congested situation using slow rhythm.

  7. Instrumentation of Slow Cook-Off Events

    NASA Astrophysics Data System (ADS)

    Sandusky, H. W.; Chambers, G. P.

    2002-07-01

    An arrangement was developed for validating models of slow cook-off. Experiments were conducted on the explosive PBXN-109 with measurements of temperature, pressure, and volume until the onset of reaction; and measurements of case velocity and blast overpressure during reaction. The goal is to relate changes in the energetic material during heating with time and position for onset of reaction plus reaction violence as a function of sample size, confinement, gas sealing, and heating profile. A mild range of reactions occurred as evidenced by fragmentation of the confinement into mostly large pieces; however, at the highest confinement no sample was recovered.

  8. Slow excited state phototautomerization in 3-hydroxyisoquinoline.

    PubMed

    Joshi, Neeraj Kumar; Arora, Priyanka; Pant, Sanjay; Joshi, Hem Chandra

    2014-06-01

    In the present work we report the spectral and photophysical properties of 3-hydroxyisoquinoline in various protic/aprotic solvents. Our steady state and time resolved fluorescence data indicates that in the monomer form of 3HIQ phototautomerization can take place in the excited state through excited state intramolecular proton, while as per earlier suggestions phototautomerization in 3HIQ occurs in dimer or complex (in the presence of acetic acid) form. Moreover, we find rather slow tautomerization (occurring on the nanosecond scale). It is found that proton transfer occurs both in the ground as well as excited states and is controlled by the polarity of the solvent.

  9. Lead Slowing Down Spectrometer Status Report

    SciTech Connect

    Warren, Glen A.; Anderson, Kevin K.; Bonebrake, Eric; Casella, Andrew M.; Danon, Yaron; Devlin, M.; Gavron, Victor A.; Haight, R. C.; Imel, G. R.; Kulisek, Jonathan A.; O'Donnell, J. M.; Weltz, Adam

    2012-06-07

    This report documents the progress that has been completed in the first half of FY2012 in the MPACT-funded Lead Slowing Down Spectrometer project. Significant progress has been made on the algorithm development. We have an improve understanding of the experimental responses in LSDS for fuel-related material. The calibration of the ultra-depleted uranium foils was completed, but the results are inconsistent from measurement to measurement. Future work includes developing a conceptual model of an LSDS system to assay plutonium in used fuel, improving agreement between simulations and measurement, design of a thorium fission chamber, and evaluation of additional detector techniques.

  10. Slow slip event at Kilauea Volcano

    USGS Publications Warehouse

    Poland, Michael P.; Miklius, Asta; Wilson, J. David; Okubo, Paul G.; Montgomery-Brown, Emily; Segall, Paul; Brooks, Benjamin; Foster, James; Wolfe, Cecily; Syracuse, Ellen; Thurbe, Clifford

    2010-01-01

    Early in the morning of 1 February 2010 (UTC; early afternoon 31 January 2010 local time), continuous Global Positioning System (GPS) and tilt instruments detected a slow slip event (SSE) on the south flank of Kilauea volcano, Hawaii. The SSE lasted at least 36 hours and resulted in a maximum of about 3 centimeters of seaward displacement. About 10 hours after the start of the slip, a flurry of small earthquakes began (Figure 1) in an area of the south flank recognized as having been seismically active during past SSEs [Wolfe et al., 2007], suggesting that the February earthquakes were triggered by stress associated with slip [Segall et al., 2006].

  11. Slow relaxation in structure-forming ferrofluids.

    PubMed

    Sreekumari, Aparna; Ilg, Patrick

    2013-10-01

    We study the behavior of colloidal magnetic fluids at low density for various dipolar interaction strengths by performing extensive Langevin dynamics simulations with model parameters that mimic cobalt-based ferrofluids used in experiments. Our study mainly focuses on the structural and dynamical properties of dipolar fluids and the influence of structural changes on their dynamics. Drastic changes from chainlike to networklike structures in the absence of an external magnetic field are observed. This crossover plays an important role in the slowing down of dynamics that is reflected in various dynamical properties including the tracer diffusion and the viscosity and also in the structural relaxation. PMID:24229180

  12. Slowing after Observed Error Transfers across Tasks

    PubMed Central

    Wang, Lijun; Pan, Weigang; Tan, Jinfeng; Liu, Congcong; Chen, Antao

    2016-01-01

    After committing an error, participants tend to perform more slowly. This phenomenon is called post-error slowing (PES). Although previous studies have explored the PES effect in the context of observed errors, the issue as to whether the slowing effect generalizes across tasksets remains unclear. Further, the generation mechanisms of PES following observed errors must be examined. To address the above issues, we employed an observation-execution task in three experiments. During each trial, participants were required to mentally observe the outcomes of their partners in the observation task and then to perform their own key-press according to the mapping rules in the execution task. In Experiment 1, the same tasksets were utilized in the observation task and the execution task, and three error rate conditions (20%, 50% and 80%) were established in the observation task. The results revealed that the PES effect after observed errors was obtained in all three error rate conditions, replicating and extending previous studies. In Experiment 2, distinct stimuli and response rules were utilized in the observation task and the execution task. The result pattern was the same as that in Experiment 1, suggesting that the PES effect after observed errors was a generic adjustment process. In Experiment 3, the response deadline was shortened in the execution task to rule out the ceiling effect, and two error rate conditions (50% and 80%) were established in the observation task. The PES effect after observed errors was still obtained in the 50% and 80% error rate conditions. However, the accuracy in the post-observed error trials was comparable to that in the post-observed correct trials, suggesting that the slowing effect and improved accuracy did not rely on the same underlying mechanism. Current findings indicate that the occurrence of PES after observed errors is not dependent on the probability of observed errors, consistent with the assumption of cognitive control account

  13. BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTHWEST. - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

  14. Improved Slow Light Capacity In Graphene-based Waveguide

    PubMed Central

    Hao, Ran; Peng, Xi-Liang; Li, Er-Ping; Xu, Yang; Jin, Jia-Min; Zhang, Xian-Min; Chen, Hong-Sheng

    2015-01-01

    We have systematically investigated the wideband slow light in two-dimensional material graphene, revealing that graphene exhibits much larger slow light capability than other materials. The slow light performances including material dispersion, bandwidth, dynamic control ability, delay-bandwidth product, propagation loss, and group-velocity dispersion are studied, proving graphene exhibits significant advantages in these performances. A large delay-bandwidth product has been obtained in a simple yet functional grating waveguide with slow down factor c/vg at 163 and slow light bandwidth Δω at 94.4 nm centered at 10.38 μm, which is several orders of magnitude larger than previous results. Physical explanation of the enhanced slow light in graphene is given. Our results indicate graphene is an excellent platform for slow light applications, promoting various future slow light devices based on graphene. PMID:26478563

  15. Slow earthquakes, preseismic velocity changes, and the origin of slow frictional stick-slip.

    PubMed

    Kaproth, Bryan M; Marone, C

    2013-09-13

    Earthquakes normally occur as frictional stick-slip instabilities, resulting in catastrophic failure and seismic rupture. Tectonic faults also fail in slow earthquakes with rupture durations of months or more, yet their origin is poorly understood. Here, we present laboratory observations of repetitive, slow stick-slip in serpentinite fault zones and mechanical evidence for their origin. We document a transition from unstable to stable frictional behavior with increasing slip velocity, providing a mechanism to limit the speed of slow earthquakes. We also document reduction of P-wave speed within the active shear zone before stick-slip events. If similar mechanisms operate in nature, our results suggest that higher-resolution studies of elastic properties in tectonic fault zones may aid in the search for reliable earthquake precursors.

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

    PubMed

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

    2009-11-01

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

  17. Early vestibular processing does not discriminate active from passive self-motion if there is a discrepancy between predicted and actual proprioceptive feedback.

    PubMed<