Proprioceptive Stimulation Research Articles

Cortical Activations and BCI Performances at Different Speeds of Visual and Proprioceptive Stimulation.

Motor imagery based brain-computer interface (MI-BCI) is one of the most common paradigms utilized in neurofeedback training (NFT) for rehabilitation engineering. Specifically, finding an appropriate feedback protocol is significantly important to improve the effectiveness of the motor training system. To this end, we investigated the electroencephalography(EEG) oscillatory patterns measured by event-related desynchronization (ERD) when sixteen participants accepted the visual and proprioceptive stimulation achieving the kinematic hand grasping movements at three different speeds (i.e. 1/3 Hz, 2/3 Hz and 1 Hz). The EEG results indicated that the ERD patterns showed no significant difference in sensorimotor cortex (i.e. C3 and FC3 channels) by comparing the three conditions. Nevertheless, the 2/3 Hz stimulation speed could achieve a significantly better classification performance than the other two conditions across all participants. Therefore, the visual and proprioceptive electrical stimulation achieving the kinematic hand grasping at 2/3 Hz speed might provide an available approach for the online MI-BCI system based NFT system in the future.

A visual-haptic neurofeedback training improves sensorimotor cortical activations and BCI performance.

Neurofeedback training (NFT) could provide a novel way to investigate or restore the impaired brain function and neuroplasticity. However, it remains unclear how much the different feedback modes can contribute to NFT training. Specifically, whether they can enhance the cortical activations for motor training. To this end, our study proposed a brain-computer interface (BCI) based visual-haptic NFT incorporating synchronous visual scene and proprioceptive electrical stimulation feedback. By comparison between previous and posterior control sessions, the cortical activations measured by multi-band (i.e. alpha_1: 8-10Hz, alpha_2: 11-13Hz, beta_1: 15-20Hz and beta_2: 22-28Hz) lateralized relative event-related desynchronization (lrERD) patterns were significantly enhanced after NFT. And the classification performance was also significantly improved, achieving a ~9% improvement and reaching ~85% in mean classification accuracy from a relatively low MI-BCI performance. These findings validate the feasibility of our proposed visual- haptic NFT approach to improve sensorimotor cortical activations and BCI performance during motor training.

Mobilisation And Tactile (Sensory) Stimulation For The Foot Post Stroke: Opinions And Perceptions Of Experienced Therapists

Background/Aims Intensive proprioceptive stimulation applied to the paretic hand post-stroke, using a complex hands-on intervention known as mobilisation and tactile stimulation, has reduced motor impairment and improved hand function in sub-acute and chronic stroke. While, anecdotally, mobilisation and tactile stimulation is also applied to the paretic foot to prepare it for standing, its use in stroke rehabilitation and effects on standing and balance have not been evaluated. Therefore, expert clinicians' experiences, opinions and perceptions of using mobilisation and tactile stimulation in routine clinical practice were explored to inform a subsequent feasibility study of mobilisation and tactile stimulation for the paretic foot post-stroke. Methods Following ethical approval, focus groups were undertaken: using purposive sampling, physiotherapists and occupational therapists with >12 months experience of stroke rehabilitation were recruited from a regional special interest group. A pilot study (n=4) and main study (n=7) explored content and application of hands-on therapy for the paretic foot, and the perceived impact of sensory loss on lower limb function. Data were audio-taped and transcribed verbatim. Thematic analysis was undertaken. Results All 11 therapists had previous experience of using mobilisation and tactile stimulation for the foot post-stroke. Three main themes were identified: (1) therapeutic intervention (sub-themes: therapy content, sensation, adjuncts, the foot as an active base of support and preparation for function); (2) 24-hour care; and (3) analysis (sub-themes: outcome measures, response to treatment). The most common adjuncts to mobilisation and tactile stimulation were orthotics and task-specific training. The importance of mobilisation and tactile stimulation in restoring foot alignment, sensory feedback and progression of the patient towards weight bearing and ambulation in the clinical setting was highlighted. Conclusions Mobilisation and tactile stimulation is a complex intervention used in stroke rehabilitation to enhance weight bearing and ambulation post stroke. Further research into its effects on the foot and lower limb is warranted in order to evaluate it and determine its evidence base for inclusion in routine clinical practice. Alternative methods of applying proprioceptive stimulation should also be considered, for example use of textured insoles, and relative effectiveness of these explored in clinical trials.

Kinaesthetic illusion shapes the cortical plasticity evoked by action observation.

The combination of action observation (AO) and a peripheral nerve stimulation has been shown to induce plasticity in the primary motor cortex (M1). However, using peripheral nerve stimulation little is known about the specificity of the sensory inputs. The current study, using muscle tendon vibration to stimulate muscle spindles and transcranial magnetic stimulation to assess M1 excitability, investigated whether a proprioceptive stimulation leading to a kinaesthetic illusion of movement (KI) was able to evoke M1 plasticity when combined with AO. M1 excitability increased immediately and up to 60min after AO-KI stimulation as a function of the vividness of the perceived illusion, and only when the movement directions of AO and KI were congruent. Tactile stimulation coupled with AO and KI alone were not sufficient to induce M1 plasticity. This methodology might be proposed to subjects during a period of immobilization to promote M1 activity without requiring any voluntary movement. Physical practice is crucial to evoke cortical plasticity, but motor cognition techniques, such as action observation (AO), have shown their potentiality in promoting it when associated with peripheral afferent inputs, without the need of performing a movement. Here we investigated whether the combination of AO and a proprioceptive stimulation, able to evoke a kinaesthetic illusion of movement (KI), induced plasticity in the primary motor cortex (M1). In the main experiment, the role of congruency between the observed action and the illusory movement was explored together with the importance of the specificity of the sensory input modality (proprioceptive vs. tactile stimulation) to induce plasticity in M1. Further, a control experiment was carried out to assess the role of the mere kinaesthetic illusion on M1 excitability. Results showed that the combination of AO and KI evoked plasticity in M1, with an increase of the excitability immediately and up to 60min after the conditioning protocol (P always <0.05). Notably, a significant increase in M1 excitability occurred only when the directions of the observed and illusory movements were congruent. Further, a significant positive linear relationship was found between the amount of M1 excitability increase and the vividness of the perceived illusion (P=0.03). Finally, the tactile stimulation coupled with AO was not sufficient to induce changes in M1 excitability as well as the KI alone. All these findings indicate the importance of combining different sensory input signals to induce plasticity in M1, and that proprioception is the most suitable sensory modality to allow it.

Cortical recruitment and functional dynamics in postural control adaptation and habituation during vibratory proprioceptive stimulation

Objective. Maintaining upright posture is a complex task governed by the integration of afferent sensorimotor and visual information with compensatory neuromuscular reactions. The objective of the present work was to characterize the visual dependency and functional dynamics of cortical activation during postural control. Approach. Proprioceptic vibratory stimulation of calf muscles at 85 Hz was performed to evoke postural perturbation in open-eye (OE) and closed-eye (CE) experimental trials, with pseudorandom binary stimulation phases divided into four segments of 16 stimuli. 64-channel EEG was recorded at 512 Hz, with perturbation epochs defined using bipolar electrodes placed proximal to each vibrator. Power spectra variation and linearity analysis was performed via fast Fourier transformation into six frequency bands (Δ, 0.5–3.5 Hz; θ, 3.5–7.5 Hz; α, 7.5–12.5 Hz; β, 12.5–30 Hz; , 30–50 Hz; and , 50–80 Hz). Finally, functional connectivity assessment was explored via network segregation and integration analyses. Main results. Spectra variation showed waveform and vision-dependent activation within cortical regions specific to both postural adaptation and habituation. Generalized spectral variation yielded significant shifts from low to high frequencies in CE adaptation trials, with overall activity suppressed in habituation; OE trials showed the opposite phenomenon, with both adaptation and habituation yielding increases in spectral power. Finally, our analysis of functional dynamics reveals novel cortical networks implicated in postural control using EEG source-space brain networks. In particular, our reported significant increase in local θ connectivity may signify the planning of corrective steps and/or the analysis of falling consequences, while α band network integration results reflect an inhibition of error detection within the cingulate cortex, likely due to habituation. Significance. Our findings principally suggest that specific cortical waveforms are dependent upon the availability of visual feedback, and we furthermore present the first evidence that local and global brain networks undergo characteristic modification during postural control.

Podokinetic After-Rotation Is Transiently Enhanced or Reversed by Unilateral Axial Muscle Proprioceptive Stimulation.

Unilateral axial muscle vibration, eliciting a proprioceptive volley, is known to incite steering behavior. Whole-body rotation while stepping in place also occurs as an after-effect of stepping on a circular treadmill (podokinetic after-rotation, PKAR). Here, we tested the hypothesis that PKAR is modulated by axial muscle vibration. If both phenomena operate through a common pathway, enhancement or cancellation of body rotation would occur depending on the stimulated side when vibration is administered concurrently with PKAR. Seventeen subjects participated in the study. In one session, subjects stepped in place eyes open on the center of a platform that rotated counterclockwise 60°/s for 10 min. When the platform stopped, subjects continued stepping in place blindfolded. In other session, a vibratory stimulus (100 Hz, 2 min) was administered to right or left paravertebral muscles at lumbar level at two intervals during the PKAR. We computed angular body velocity and foot step angles from markers fixed to shoulders and feet. During PKAR, all subjects rotated clockwise. Decreased angular velocity was induced by right vibration. Conversely, when vibration was administered to the left, clockwise rotation velocity increased. The combined effect on body rotation depended on the time at which vibration was administered during PKAR. Under all conditions, foot step angle was coherent with shoulder angular velocity. PKAR results from continuous asymmetric input from the muscles producing leg rotation, while axial muscle vibration elicits a proprioceptive asymmetric input. Both conditioning procedures appear to produce their effects through a common mechanism. We suggest that both stimulations would affect our straight ahead by combining their effects in an algebraic mode.

Attenuated beta rebound to proprioceptive afferent feedback in Parkinson\u2019s disease

Motor symptoms are defining traits in the diagnosis of Parkinson’s disease (PD). A crucial component in motor function is the integration of afferent proprioceptive sensory feedback. Previous studies have indicated abnormal movement-related cortical oscillatory activity in PD, but the role of the proprioceptive afference on abnormal oscillatory activity in PD has not been elucidated. We examine the cortical oscillations in the mu/beta-band (8–30 Hz) in the processing of proprioceptive stimulation in PD patients, ON/OFF levodopa medication, as compared to that of healthy controls (HC). We used a proprioceptive stimulator that generated precisely controlled passive movements of the index finger and measured the induced cortical oscillatory responses following the proprioceptive stimulation using magnetoencephalography. Both PD patients and HC showed a typical beta-band desynchronization during the passive movement. However, the subsequent beta rebound after the passive movement that was almost absent in PD patients compared to HC. Furthermore, we found no difference in the degree of beta rebound attenuation between patients ON and OFF levodopa medication. The results demonstrate a disease-related deterioration in cortical processing of proprioceptive afference in PD.

Severe Perinatal Hypoxic-Ischemic Brain Injury Induces Long-Term Sensorimotor Deficits, Anxiety-Like Behaviors and Cognitive Impairment in a Sex-, Age- and Task-Selective Manner in C57BL/6 Mice but Can Be Modulated by Neonatal Handling.

Perinatal brain injury (PBI) leads to neurological disabilities throughout life, from motor deficits, cognitive limitations to severe cerebral palsy. Yet, perinatal brain damage has limited therapeutic outcomes. Besides, the immature brain of premature children is at increased risk of hypoxic/ischemic (HI) injury, with males being more susceptible to it and less responsive to protective/therapeutical interventions. Here, we model in male and female C57BL/6 mice, the impact of neonatal HI and the protective effects of neonatal handling (NH), an early life tactile and proprioceptive sensory stimulation. From postnatal day 1 (PND1, modeling pre-term) to PND21 randomized litters received either NH or left undisturbed. HI brain damage occurred by permanent left carotid occlusion followed by hypoxia at PND7 (modeling full-term) in half of the animals. The behavioral and functional screening of the pups at weaning (PND23) and their long-term outcomes (adulthood, PND70) were evaluated in a longitudinal study, as follows: somatic development (weight), sensorimotor functions (reflexes, rods and hanger tests), exploration [activity (ACT) and open-field (OF) test], emotional and anxiety-like behaviors [corner, open-field and dark-light box (DLB) tests], learning and memory [T-maze (TM) and Morris Water-Maze (MWM)]. HI induced similar brain damage in both sexes but affected motor development, sensorimotor functions, induced hyperactivity at weaning, and anxiety-like behaviors and cognitive deficits at adulthood, in a sex- and age-dependent manner. Thus, during ontogeny, HI affected equilibrium especially in females and prehensility in males, but only reflexes at adulthood. Hyperactivity of HI males was normalized at adulthood. HI increased neophobia and other anxiety-like behaviors in males but emotionality in females. Both sexes showed worse short/long-term learning, but memory was more affected in males. Striking neuroprotective effects of NH were found, with significantly lower injury scores, mostly in HI males. At the functional level, NH reversed the impaired reflex responses and improved memory performances in hippocampal-dependent spatial-learning tasks, especially in males. Finally, neuropathological correlates referred to atrophy, neuronal densities and cellularity in the affected areas [hippocampal-CA, caudate/putamen, thalamus, neocortex and corpus callosum (CC)] point out distinct neuronal substrates underlying the sex- and age- functional impacts of these risk/protection interventions on sensorimotor, behavioral and cognitive outcomes from ontogeny to adulthood.

Optimization of Proprioceptive Stimulation Frequency and Movement Range for fMRI.

For vision, audition and tactile sense, the optimal stimulus frequency for fMRI is somewhat known. For proprioception, i.e., the “movement sense”, however, the optimal frequency is unknown. We studied the effect of passive-finger-movement frequency on proprioceptive fMRI responses using a novel pneumatic-movement actuator. Eleven healthy right-handed volunteers participated in the study. The movement actuator passively moved the participant’s right index finger at frequencies of 0.3, 1, 3, 6, 9, or 12 Hz in a blocked design. A functional localizer was used to define regions-of-interest in SI and SII cortices. In addition, effect of movement range on the fMRI responses was tested in a separate session with 1, 3, 5, and 7 mm movement ranges at a fixed 2 Hz frequency. In primary somatosensory (SI) cortex, the responses were stronger at 3 Hz than at 0.3 Hz (p < 0.001) or 1 Hz (p < 0.05), and at ≥6 Hz than 0.3 Hz (p < 0.001 for frequencies ≥ 6 Hz). In secondary somatosensory (SII) cortex, all movements, except at 0.3 Hz, elicited significant responses of similar strength. In addition, 6, 9, and 12-Hz movements elicited a significant offset response in both SI and SII cortices (p < 0.001–0.05). SI cortex required a total stimulation duration of 4 min to elicit significant activations at the group-level whereas for SII cortex 1 min 20 s was sufficient. Increase in the movement range led to stronger responses in SI cortex, but not in SII cortex. Movements above 3 Hz elicited the strongest SI cortex responses, and increase in the movement range enhanced the response strength. We thus recommend that movements at 3–6 Hz with a movement range of 5 mm or higher to be used in future studies of proprioception. Our results are in-line with previous fMRI and PET studies using tactile or median nerve stimulation at different stimulation frequencies.

Proposal for Psychomotor Development According to A.R. Luria’s Conception: New Data in Mexico

The aim of this work was to test a program for psychomotor development based on Luria´s concept of three functional brain units or blocks and the necessity of stimulation of the first functional unit in early childhood. Stimulation of subcortical systems associated with psychomotor and cognitive regulation may help to set thebasis for positive functioning of the cerebral cortex in the coming years. Vestibular exercises and proprioceptive stimulation were used. All exercises included significant communicative activity as described by Vigotsky and Lisina, which provide positive direct emotional contact between adult and child. Thirty-six babies with neurological risk were included in the study, along with their parents. After 300 days in the stimulation program, all the children presented positive functional development. We conclude that positive effects of these programs for correction and psychological development may be achieved during the first year of life.&#x0D; Keywords: neurological risk, emotional contact, joint activity, vestibular stimulation

Effect of rebound exercises on balance in children with spastic diplegia

Background/Aims: Rebound exercises using a trampoline and BOSU ball provides proprioceptive and vestibular stimulation and improve postural control and balance. Although there is no evidence to support the benefits of using rebound exercises, it is widely used in rehabilitation. The current study aimed to investigate the effect of a rebound exercises on balance in children with spastic diplegia. Methods: Forty children with spastic diplegia from both sexes, age ranged from 6 to 10 years participated in this study. They were allocated randomly into two groups of equal numbers, one was the control group and the other was the study group. The control group received a designed physical therapy programme for 1 hour and balance training for 1 hour. The study group received the same physical therapy programme as the control group in addition to rebound exercises for one hour. The treatment programmes of both groups were conducted 3 days a week for 2 successive months. The assessments of dynamic balance were conducted pre, post treatment and 1 month after the end of the treatment using the Biodex balance system. Results: Baseline and post treatment comparisons showed a statistically significant improvement of balance in the two groups. There was no significant difference between post treatment and post 1 month follow-up in the control group, while a significant difference was recorded in the study group. Conclusions: Rebound exercises conducted with a designed physical therapy programme is beneficial and has a significant effect in improving balance.

Pain Control by Proprioceptive and Exteroceptive Stimulation at the Trigeminal Level.

The Gate Control Theory of pain, published more than half a century ago to explain nociceptive modulation of peripheral sensory input, assumes inhibition of incoming nociceptive (pain) information produced by mechanical stimulation. To verify the presence of such a gate control mechanism at the level of the human trigeminal system, we evaluated the effects on pain sensation of a proprioceptive trigeminal stimulation induced by mandibular extension. We found that such a stimulation, applied for 7 min, was effective in increasing both the threshold and tolerance of tooth pain induced by electrical activation of dental nociceptors. Moreover the antinociceptive effect lasted for several minutes after the proprioceptive stimulus had ceased. We also tested whether an exteroceptive palatal stimulation superimposed on the proprioceptive stimulation would increase the effects on tooth pain perception of human volunteers. We observed that the exteroceptive stimulation significantly increased the antinociceptive effect induced by the sole proprioceptive stimulation. The physiological mechanisms and the possible implications of these observations are discussed.

Role of spine in falls: Prevention of falls and unsteadiness of gait through reeducation of proprioceptors of vertebral facet joints

The aim of this study was to determine the outcome of dynamic counterstrain and proprioceptive stimulation of specific vertebral facet joints to achieve reduction in risk of falls by reducing gait unsteadiness. Two groups were studied. Group A consisted of 39 patients who had gait disorder and propensity to falls, referred for fall prevention. All had comprehensive musculoskeletal and neurological evaluations. Subjects in this group were not able to return for follow up due to the distance from our institution. They all signed the consent form and were videotaped. Group B consisted of twelve subjects who were able to return for follow up and all underwent 2 supervised training sessions in our outpatient clinic. They had formal laboratory gait analysis and computerized dynamic posturography at baseline and follow up. They were instructed for a 4-week spinal proprioceptive extension exercise dynamic (SPEED) program to be performed at home with use of a weighted kypho-orthosis (WKO). The WKO applied properly accentuates a patient's perception of spinal joint position. All subjects had the trial of spinal proprioceptive extension exercise dynamic (SPEED) program. Results of Gait lab analysis, computerized dynamic posturography, strength evaluation or videotapes were reviewed. Group A was videotaped before and after SPEED and displayed noticeable improvement to their surprise. Group B, after a 4-week intervention, showed a significant change in balance ( P = .003) and several gait parameters ( P < .05). Mean back extensor strength improved significantly from baseline (144.0 ± 46.5 N) to follow-up (198.6 ± 55.2 N; P < 00l). Gait and risk of falls improved significantly after trial of SPEED program for reeducation of proprioception by application of mechanical counterstrain to specific areas of spine. This method of intervention might potentially lead to novel investigations for managing patients with unsteadiness of gait and propensity to falls.

Efficacy of the Regent Suit-based rehabilitation on gait EMG patterns in hemiparetic subjects: a pilot study.

The recovery of the functional limb mobility of patients with cerebral damages can take great benefit of the role offered by proprioceptive rehabilitation. Recently have been developed a special Regent Suit (RS) for rehabilitative applications. Actually, there are preliminary studies which describes the effects of RS on gait recovery of stroke patients in acute stage, but none in chronic stage. Moreover, it is known that motor recovery does not always reflect improvements of the muscle activity and coactivity. To investigate the effects of proprioceptive stimulation induced by the Regent Suit (RS) on the EMG patterns during gait in post-stroke chronic patients. Randomized controlled trial. S. Maugeri Foundation, Telese Terme (BN), Italy. Patients have been randomly assigned into two equal groups of 20 patients: experimental group and traditional group. Further, a control group of 20 healthy subjects have been enrolled. The traditional group attended a rehabilitation program composed by neuro-motor exercises without the RS, the experimental group performed the same rehabilitation program while wearing the RS. The NIH Stroke Scale (NIHSS), the Barthel Index (BI), the Functional Independent Measure (FIM) and the Berg Balance Scale (BBS) have been evaluated. EMG analysis has been performed considering the muscle activation timing over the gait of the soleus, tibialis anterior, semitendinosus and vastus lateralis muscles by decomposing the EMG signals into Gaussian pulses. Then, the symmetry of muscle activation and the muscle synergy patterns over the gait cycle have been assessed. The proprioceptive stimulation of the RS-based treatment induces higher and remarkable restoration of the normal muscle activation timing, also increasing the muscle symmetry and reducing the pathological muscle coactivation on both affected and non-affected sides. These results suggest confirm that a RS-based treatment is more effective than usual care in improving the EMG patterns during locomotion and daily living activities in chronic post-stroke subjects. The proprioceptive rehabilitation Regent Suit based has an impact on motor function in stroke patients during gait.

Standing postural reaction to visual and proprioceptive stimulation in chronic acquired demyelinating polyneuropathy.

To investigate the weight of visual and proprioceptive inputs, measured indirectly in standing position control, in patients with chronic acquired demyelinating polyneuropathy (CADP). Prospective case study. Twenty-five patients with CADP and 25 healthy controls. Posture was recorded on a double force platform. Stimulations were optokinetic (60°/s) for visual input and vibration (50 Hz) for proprioceptive input. Visual stimulation involved 4 tests (upward, downward, rightward and leftward) and proprioceptive stimulation 2 tests (triceps surae and tibialis anterior). A composite score, previously published and slightly modified, was used for the recorded postural signals from the different stimulations. Despite their sensitivity deficits, patients with CADP were more sensitive to proprioceptive stimuli than were healthy controls (mean composite score 13.9 ((standard deviation; SD) 4.8) vs 18.4 (SD 4.8), p = 0.002). As expected, they were also more sensitive to visual stimuli (mean composite score 10.5 (SD 8.7) vs 22.9 (SD 7.5), p <0.0001). These results encourage balance rehabilitation of patients with CADP, aimed at promoting the use of proprioceptive information, thereby reducing too-early development of visual compensation while proprioception is still available.

Recovery of the 20 Hz Rebound to Tactile and Proprioceptive Stimulation after Stroke.

Sensorimotor integration is closely linked to changes in motor-cortical excitability, observable in the modulation of the 20 Hz rhythm. After somatosensory stimulation, the rhythm transiently increases as a rebound that reflects motor-cortex inhibition. Stroke-induced alterations in afferent input likely affect motor-cortex excitability and motor recovery. To study the role of somatosensory afferents in motor-cortex excitability after stroke, we employed magnetoencephalographic recordings (MEG) at 1–7 days, one month, and 12 months in 23 patients with stroke in the middle cerebral artery territory and 22 healthy controls. The modulation of the 20 Hz motor-cortical rhythm was evaluated to two different somatosensory stimuli, tactile stimulation, and passive movement of the index fingers. The rebound strengths to both stimuli were diminished in the acute phase compared to the controls and increased significantly during the first month after stroke. However, only the rebound amplitudes to tactile stimuli fully recovered within the follow-up period. The rebound strengths in the affected hemisphere to both stimuli correlated strongly with the clinical scores across the follow-up. The results show that changes in the 20 Hz rebound to both stimuli behave similarly and occur predominantly during the first month. The 20 Hz rebound is a potential marker for predicting motor recovery after stroke.

An Interesting Eating Epilepsy Case Induced by Bread Eating

Eating epilepsy is evaluated in reflex epilepsies (RE). Different genetic, ethnic, acquired factors and to the bulky meals rich in carbohydrates consumed may play a role in etiology of RE or supported by a brain lesion. In this situation, seizures provoked by eating is a rare entity and the ictal semiology differs from patient to patient. Focal impaired awareness seizure is most commonly described. Diffuse cerebral damage is often noted on MRI. Reproduction of these seizures during EEG recording is often difficult as the stimulus is frequently complex, involving different components of eating, such as the sight of food, proprioceptive, olfactive or gustative stimulations, chewing, salivation, and gastric distension of eating. The case presented here was an eating epilepsy case triggered by bread eating and implicated, based on EEG and MRI.

Robotic Assistance for Training Finger Movement Using a Hebbian Model: A Randomized Controlled Trial

Background. Robots that physically assist movement are increasingly used in rehabilitation therapy after stroke, yet some studies suggest robotic assistance discourages effort and reduces motor learning. Objective. To determine the therapeutic effects of high and low levels of robotic assistance during finger training. Methods. We designed a protocol that varied the amount of robotic assistance while controlling the number, amplitude, and exerted effort of training movements. Participants (n = 30) with a chronic stroke and moderate hemiparesis (average Box and Blocks Test 32 ± 18 and upper extremity Fugl-Meyer score 46 ± 12) actively moved their index and middle fingers to targets to play a musical game similar to GuitarHero 3 h/wk for 3 weeks. The participants were randomized to receive high assistance (causing 82% success at hitting targets) or low assistance (55% success). Participants performed ~8000 movements during 9 training sessions. Results. Both groups improved significantly at the 1-month follow-up on functional and impairment-based motor outcomes, on depression scores, and on self-efficacy of hand function, with no difference between groups in the primary endpoint (change in Box and Blocks). High assistance boosted motivation, as well as secondary motor outcomes (Fugl-Meyer and Lateral Pinch Strength)—particularly for individuals with more severe finger motor deficits. Individuals with impaired finger proprioception at baseline benefited less from the training. Conclusions. Robot-assisted training can promote key psychological outcomes known to modulate motor learning and retention. Furthermore, the therapeutic effectiveness of robotic assistance appears to derive at least in part from proprioceptive stimulation, consistent with a Hebbian plasticity model.

Enhancement of rowing performance in athletes after focal muscle vibration therapy

Muscle vibration has been reported to induce positive long lasting effects on proprioception when applied on specific body segment.The aim of this study was to evaluate the effect of focal muscle vibration applied on quadriceps and latissimus dorsi muscles inathletes evaluated during rowing test. Sixteen volunteered national level sculling stroke rowers were randomized in a study groupand in a control group (treated with sham vibration). The overall kinematics consistency, joints angular acceleration patterns andperformance test were used for evaluation. Results showed statistical significant differences for angular accelerations at the knee andshoulder joints and muscles timings. Vibration treatment seems to be a useful proprioceptive stimulation in sport activities toimprove muscle control and performance.

Quantification of task-dependent cortical activation evoked by robotic continuous wrist joint manipulation in chronic hemiparetic stroke

BackgroundCortical damage after stroke can drastically impair sensory and motor function of the upper limb, affecting the execution of activities of daily living and quality of life. Motor impairment after stroke has been thoroughly studied, however sensory impairment and its relation to movement control has received less attention. Integrity of the somatosensory system is essential for feedback control of human movement, and compromised integrity due to stroke has been linked to sensory impairment.MethodsThe goal of this study is to assess the integrity of the somatosensory system in individuals with chronic hemiparetic stroke with different levels of sensory impairment, through a combination of robotic joint manipulation and high-density electroencephalogram (EEG). A robotic wrist manipulator applied continuous periodic disturbances to the affected limb, providing somatosensory (proprioceptive and tactile) stimulation while challenging task execution. The integrity of the somatosensory system was evaluated during passive and active tasks, defined as ‘relaxed wrist’ and ‘maintaining 20% maximum wrist flexion’, respectively. The evoked cortical responses in the EEG were quantified using the power in the averaged responses and their signal-to-noise ratio.ResultsThirty individuals with chronic hemiparetic stroke and ten unimpaired individuals without stroke participated in this study. Participants with stroke were classified as having severe, mild, or no sensory impairment, based on the Erasmus modification of the Nottingham Sensory Assessment. Under passive conditions, wrist manipulation resulted in contralateral cortical responses in unimpaired and chronic stroke participants with mild and no sensory impairment. In participants with severe sensory impairment the cortical responses were strongly reduced in amplitude, which related to anatomical damage. Under active conditions, participants with mild sensory impairment showed reduced responses compared to the passive condition, whereas unimpaired and chronic stroke participants without sensory impairment did not show this reduction.ConclusionsRobotic continuous joint manipulation allows studying somatosensory cortical evoked responses during the execution of meaningful upper limb control tasks. Using such an approach it is possible to quantitatively assess the integrity of sensory pathways; in the context of movement control this provides additional information required to develop more effective neurorehabilitation therapies.