Effect of concurrent action observation, peripheral nerve stimulation and motor imagery on dexterity in patients after stroke: a pilot study.

Research to improve and expand treatment options for motor impairment after stroke remains an important issue in rehabilitation as the reduced ability to move affected limbs is still a limiting factor in the selection of training content for stroke patients. The combination of action observation and peripheral nerve stimulation is a promising method for inducing increased excitability and plasticity in the primary motor cortex of healthy subjects. In addition, as reported in the literature, the use of action observation and motor imagery in conjunction has an advantage over the use of one or the other alone in terms of the activation of motor-related brain regions. The aim of the pilot study was thus to combine these findings into a multimodal approach and to evaluate the potential impact of the concurrent application of the three methods on dexterity in stroke patients. The paradigm developed accordingly was tested with 10 subacute patients, in whom hand dexterity, thumb-index pinch force and thumb tapping speed were measured for a baseline assessment and directly before and after the single intervention. During the 10-min session, patients were instructed to watch a repetitive thumb-index finger tapping movement displayed on a monitor and to imagine the sensations that would arise from physically performing the same motion. They were also repeatedly electrically stimulated at the wrist on the motorically more affected body side and asked to place their hand behind the monitor for the duration of the session to support integration of the displayed hand into their own body schema. The data provide a first indication of a possible immediate effect of a single application of this procedure on the dexterity in patients after stroke.

Feasibility of an Application-Based Outpatient Rehabilitation Program for Stroke Survivors: Acceptability and Preliminary Results for Patient-Reported Outcomes.

BACKGROUND: The majority of stroke survivors experience long-term impairments. Regular physical activity and other lifestyle modifications play an important role in rehabilitation. Outpatient rehabilitation using telemedicine might be suitable to improve functional ability and long-term secondary prevention. The Strokecoach Intervention Program (SIP, Strokecoach GmbH, Cologne, Germany) comprises training, coaching and monitoring with the aim of improving or at least maintaining functional independence and preventing further stroke through more targeted physical activity. The SIP is provided as blended care, which refers to the integrated and coordinated delivery of healthcare services that combines traditional in-person interactions with technology-mediated interventions, optimizing the use of both face-to-face and virtual modalities to enhance patient outcomes. OBJECTIVE: The aim of this study was to evaluate the acceptance of the SIP by the participants and its practical application, as well as to obtain initial indications of effects of the SIP on the basis of patient-related outcome measures, blood pressure measurements and recording of physical activity in parallel with the intervention. METHODS: Data from individuals with stroke participating in the SIP were analyzed retrospectively. Within the SIP, participants received an application-based training program, were instructed to measure their blood pressure daily and to wear an activity tracker (pedometer). During the intervention period of either 6 or 12 weeks, the participants were supported and motivated by a personal coach via a messenger application. The primary outcomes of the analysis were recruitment, acceptance of and satisfaction with the SIP. Secondary outcomes included functional measures, mobility and health-related quality of life. RESULTS: A total of 122 individuals with stroke could be recruited for the SIP. A total of 96 out of 122 were able to start the program (54% female, mean age 54.8 (SD = 13.1), 6.1 (SD = 6.6) years after stroke onset) and 88 completed the SIP. Participants wore the activity tracker on 66% and tracked their blood pressure on 72% of their intervention days. A further analyzed subgroup of 38 participants showed small improvements in patient-reported outcomes such as health-related quality of life (SF-36) with an increase of 12 points in the subdomain mental health, vitality (12.6) and physical functioning (9.1). However, no statistically significant improvements were found in other performance-based measures (Timed Up and Go test, gait speed). CONCLUSIONS: This study showed that a blended therapy approach for stroke survivors with mild to moderate impairments in the chronic phase is feasible and was highly accepted by participants, who benefitted from the additional coaching.

A commentary on Eaves et al. with a special focus on clinical neurorehabilitation.

We very much appreciate the theoretical foundations and considerations of AO, MI, and their combination AO + MI by Eaves et al. In their exploratory review, the authors highlight the beneficial effects of the combined use of AO and MI, with a particular focus on synchronous AO and MI. From a neurorehabilitation perspective, different processes may apply to patients, particularly after a stroke. As suggested by Eaves et al., the cognitive load might prevent the use of synchronous AO + MI and the asynchronous application of AO and MI might be indicated. Furthermore, some aspects should be considered when applying AO + MI in rehabilitation: screening for the patients' cognitive capabilities and MI ability, and a familiarisation programme for AO and MI, before starting with an AO + MI training. With their review, Eaves et al. propose a number of research questions in the field of neurorehabilitation that urgently need to be addressed: the use of asynchronous vs. synchronous AOMI, observation and imagination with or without errors, or use of different MI perspectives and modes in different learning stages. This commentary provides some additional suggestions on patients' MI ability and cognitive level, MI familiarisation and detailed reporting recommendations to transfer Eaves et al. findings into clinical practice.

The German Revised version of the Niigata PPPD Questionnaire (NPQ-R): Development with patient interviews and an expert Delphi consensus.

BACKGROUND: Persistent postural-perceptual dizziness (PPPD) is a functional disorder of the nervous system and currently one of the most common types of chronic dizziness. Currently existing questionnaires do not fully assess patients' specific symptoms of PPPD. The Japanese Niigata PPPD Questionnaire (NPQ) was recently developed following consensus-based diagnosis criteria. The aim of this study was to translate it into German, evaluate its content with the help of experts and patients and, if necessary, revise the original version to allow for a comprehensive assessment of patients' PPPD-related symptoms. METHODS: A 3-round expert Delphi survey and semi-structured patient interviews were conducted. 28 experts from Switzerland, Germany and Austria working in hospitals or outpatient centres were asked to complete a first questionnaire on various aspects of PPPD, on the translated, original NPQ and their own related experiences (Round one), a second questionnaire with statements regarding PPPD they could agree or disagree with using a 6-point Likert-scale (Round two), and a third survey to finally reach a consensus on statements to be integrated into the NPQ. In addition, eleven patients (mean age of 64.6±12.6 years; 6 females) were selected according to the criteria for the diagnosis of PPPD proposed by the Bárány Society and participated in a semi-structured interview asking for their opinion on the content of the original NPQ. All collected data were analysed using a descriptive evaluation and a qualitative content analysis based on verbatim transcripts. RESULTS: Seven new items were added to the NPQ based on expert and patient comments and ratings. Its revised version (NPQ-R) comprises 19 items divided into five subscales using a 7-point Likert-scale with two additional subscales relating to associated symptoms and symptom behaviour in PPPD. The new maximal score is 114 points compared to 72 for the NPQ. CONCLUSION: The NPQ-R is the first patient-reported outcome measurement for patients with PPPD in German. It should help to provide a comprehensive assessment of the intensity of PPPD in affected patients.

The challenge of measuring physiological parameters during motor imagery engagement in patients after a stroke.

Introduction: It is suggested that eye movement recordings could be used as an objective evaluation method of motor imagery (MI) engagement. Our investigation aimed to evaluate MI engagement in patients after stroke (PaS) compared with physical execution (PE) of a clinically relevant unilateral upper limb movement task of the patients' affected body side. Methods: In total, 21 PaS fulfilled the MI ability evaluation [Kinaesthetic and Visual Imagery Questionnaire (KVIQ-10), body rotation task (BRT), and mental chronometry task (MC)]. During the experiment, PaS moved a cup to distinct fields while wearing smart eyeglasses (SE) with electrooculography electrodes integrated into the nose pads and electrodes for conventional electrooculography (EOG). To verify MI engagement, heart rate (HR) and oxygen saturation (SpO2) were recorded, simultaneously with electroencephalography (EEG). Eye movements were recorded during MI, PE, and rest in two measurement sessions to compare the SE performance between conditions and SE's psychometric properties. Results: MI and PE correlation of SE signals varied between r = 0.12 and r = 0.76. Validity (cross-correlation with EOG signals) was calculated for MI (r = 0.53) and PE (r = 0.57). The SE showed moderate test-retest reliability (intraclass correlation coefficient) with r = 0.51 (95% CI 0.26-0.80) for MI and with r = 0.53 (95% CI 0.29 - 0.76) for PE. Event-related desynchronization and event-related synchronization changes of EEG showed a large variability. HR and SpO2 recordings showed similar values during MI and PE. The linear mixed model to examine HR and SpO2 between conditions (MI, PE, rest) revealed a significant difference in HR between rest and MI, and between rest and PE but not for SpO2. A Pearson correlation between MI ability assessments (KVIQ, BRT, MC) and physiological parameters showed no association between MI ability and HR and SpO2. Conclusion: The objective assessment of MI engagement in PaS remains challenging in clinical settings. However, HR was confirmed as a reliable parameter to assess MI engagement in PaS. Eye movements measured with the SE during MI did not resemble those during PE, which is presumably due to the demanding task. A re-evaluation with task adaptation is suggested.

Biomechanical comparison of walking with a new, wearable rehabilitation training device to Nordic walking and regular walking in people with chronic low back pain.

Physical activity, particularly walking, is commonly used for the treatment of diseases such as low back pain. In this study, the effects of walking wearing the new ToneFit Reha training belt (TFR) were compared to both Nordic walking and regular walking. The TFR is intended to intensify the effects of walking through the integration of two adjustable resistance handles. Ten patients with low back pain performed regular walking, Nordic walking, and walking with the TFR in a movement laboratory. The kinematics of the trunk, upper extremities, and lower extremities were measured, and the activity of the trunk and upper extremity muscles recorded. Data were analyzed by repeated-measures ANOVA and paired t-test. Kinematics indicated that walking with the TFR introduces instability that was mitigated by a delayed peak trunk rotation (peak at 63.3% gait cycle, vs. 52.8% in walking (p = .001) and 51.0% in NW (p = .007)). Upper extremity kinematics (constrained elbow flexion, high peak shoulder abduction) showed movement patterns that need to be considered when training over a longer period. Increased muscle activity was observed especially for upper extremity muscles, when training with TFR. Overall, walking with the TFR was found to be a suitable therapy for use in a rehabilitation setting.

Experiments on Vapor Pressure of KCl at Different Molar Fractions in Mixtures of KCl + K2SO4.

The objective of this paper is to measure the vapor pressure of potassium chloride (KCl) in its mixture with potassium sulfate (K2SO4). Evaporation behavior of pure salts of KCl, K2SO4, and their mixtures at different molar fractions were examined using a simultaneous thermogravimetric analyzer (STA) at different temperatures with a pair of crucibles (outer: platinum; inner: alumina). The dependence of the vapor pressure of KCl on its molar fraction in mixtures of KCl + K2SO4 was obtained on the basis of relative pressure. Results show that vapor pressure of KCl is increased to 1.2 times when a small amount of K2SO4 (molar fraction from 0.05 to 0.20) is added. Evaporation of KCl will be inhibited by K2SO4 when the molar fraction of K2SO4 is higher than 0.27, which is its fraction in the eutectic system of KCl + K2SO4. Vapor pressure of KCl decreases significantly with increasing molar fractions of K2SO4 at its inhibition scope.

ExerG: adapting an exergame training solution to the needs of older adults using focus group and expert interviews.

BACKGROUND: Exergames are playful technology-based exercise programs. They train physical and cognitive functions to preserve independence in older adults (OAs) with disabilities in daily activities and may reduce their risk of falling. This study gathered in-depth knowledge and understanding of three different user groups' experiences in and relevant needs, worries, preferences, and expectations of technology-based training, to develop an exergame training device for OAs. METHODS: We conducted a qualitative study using semi-structured focus group interviews of primary (OAs in geriatric or neurological rehabilitation) and secondary (health professionals) end users, as well as expert interviews of tertiary end users (health insurance experts or similar), exploring user perspectives on adjusting an existing exergame to OAs' needs. Voice-recorded interviews were transcribed by researchers and analyzed using thematic analysis (TA) following an inductive, data-driven, iterative approach. RESULTS: We interviewed 24 primary, 18 secondary, and 9 tertiary end users at two rehabilitation centers in Austria and Switzerland. Our TA approach identified five to six themes per user group. Themes in the primary end user group reflected aspects of safety, training goals, individuality, game environment, social interactions, and physical and technical overload. Themes in the secondary end user group comprised facets of meaningfulness, distraction through the game environment, safety, gamification elements, the availability and accessibility of the exergame. Tertiary end users' themes addressed aspects of financial reimbursement, suitable target populations, professional training for the handling of exergame devices, training goals, and concerns about the use of exergames in geriatric rehabilitation. CONCLUSIONS: In conclusion, an exergame for OAs must be safe, motivating and fully adaptable to the target group while promoting the return to or preservation of autonomy and independence in daily life. Our findings contribute to developing hard- and software extensions for the ExerG training device. Further research is needed to expand the validity of our findings to larger populations.

Influence of combined action observation and motor imagery of walking on lower limb reflex modulation in patients after stroke-preliminary results.

OBJECTIVE: The combined use of action observation and motor imagery (AOMI) is a promising technique in neurorehabilitation that can be usefully applied in addition to conventional forms of therapy. Previous studies with healthy participants showed that the mere passive observation of walking results in a phase-dependent reflex modulation in the tibialis anterior muscle that resembles the pattern occurring when walking. In patients after stroke, a similar reflex modulation was found in several lower limb muscles during the real execution of walking, but responses were blunted. To clarify whether and how lower limb reflex responses are also modulated in such patients during the combined synchronous observation and imagery of walking, medium-latency cutaneous reflexes from the tibialis anterior muscle were measured. We compared the reflex responses of seven patients after stroke during the AOMI of walking from two different conditions: (a) elicited during the end stance phase and (b) during the end swing phase, both normalized to a baseline condition. RESULTS: So far, using the identical methodological set-up as in our study with healthy individuals, we could not find any noteworthy reflex response modulation. The study was registered with the German Clinical Trials Register (DRKS00028255). TRIAL REGISTRATION: The study was registered with the German Clinical Trials Register: DRKS00028255.

Imagery ability assessments: a cross-disciplinary systematic review and quality evaluation of psychometric properties.

BACKGROUND: Over the last two centuries, researchers developed several assessments to evaluate the multidimensional construct of imagery. However, no comprehensive systematic review (SR) exists for imagery ability evaluation methods and an in-depth quality evaluation of their psychometric properties. METHODS: We performed a comprehensive systematic search in six databases in the disciplines of sport, psychology, medicine, education: SPORTDiscus, PsycINFO, Cochrane Library, Scopus, Web of Science, and ERIC. Two reviewers independently identified and screened articles for selection. COSMIN checklist was used to evaluate the methodological quality of the studies. All included assessments were evaluated for quality using criteria for good measurement properties. The evidence synthesis was summarised by using the GRADE approach. RESULTS: In total, 121 articles reporting 155 studies and describing 65 assessments were included. We categorised assessments based on their construct on: (1) motor imagery (n = 15), (2) mental imagery (n = 48) and (3) mental chronometry (n = 2). Methodological quality of studies was mainly doubtful or inadequate. The psychometric properties of most assessments were insufficient or indeterminate. The best rated assessments with sufficient psychometric properties were MIQ, MIQ-R, MIQ-3, and VMIQ-2 for evaluation of motor imagery ability. Regarding mental imagery evaluation, only SIAQ and VVIQ showed sufficient psychometric properties. CONCLUSION: Various assessments exist to evaluate an individual's imagery ability within different dimensions or modalities of imagery in different disciplines. However, the psychometric properties of most assessments are insufficient or indeterminate. Several assessments should be revised and further validated. Moreover, most studies were only evaluated with students. Further cross-disciplinary validation studies are needed including older populations with a larger age range. Our findings allow clinicians, coaches, teachers, and researchers to select a suitable imagery ability assessment for their setting and goals based on information about the focus and quality of the assessments. SYSTEMATIC REVIEWS REGISTER: PROSPERO CRD42017077004 .

Effect of Motor Imagery Training on Motor Learning in Children and Adolescents: A Systematic Review and Meta-Analysis.

Background: There is an urgent need to systematically analyze the growing body of literature on the effect of motor imagery (MI) training in children and adolescents. Methods: Seven databases and clinicaltrials.gov were searched. Two reviewers independently screened references and full texts, and extracted data (studies' methodology, MI elements, temporal parameters). Two studies were meta-analyzed providing the standard mean difference (SDM). Selected studies were evaluated with the risk of bias (RoB) and GRADE tools. Results: A total of 7238 references were retrieved. The sample size of the 22 included studies, published between 1995 and 2021, ranged from 18 to 136 participants, totaling 934 (nine to 18 years). Studies included healthy pupils, mentally retarded adolescents, children with motor coordination difficulties or with mild mental disabilities. The motor learning tasks focused on upper, lower and whole body movements. SMDs for the primary outcome of pooled studies varied between 0.83 to 1.87 (95% CI, I2, T2 varied 0.33-3.10; p = 0.001; 0-74%; 0-0.59). RoB varied between some concerns and high risk. GRADE rating was low. Conclusions: MI combined with physical practice (PP) might have a high potential for healthy and impaired children and adolescents. However, important reporting recommendations (PETTLEP, TIDieR, CONSORT) should be followed. The systematic review was registered with PROSPERO: CRD42021237361.

Multimodal Sensorimotor Integration of Visual and Kinaesthetic Afferents Modulates Motor Circuits in Humans.

Optimal motor control requires the effective integration of multi-modal information. Visual information of movement performed by others even enhances potentials in the upper motor neurons through the mirror-neuron system. On the other hand, it is known that motor control is intimately associated with afferent proprioceptive information. Kinaesthetic information is also generated by passive, external-driven movements. In the context of sensory integration, it is an important question how such passive kinaesthetic information and visually perceived movements are integrated. We studied the effects of visual and kinaesthetic information in combination, as well as isolated, on sensorimotor integration, compared to a control condition. For this, we measured the change in the excitability of the motor cortex (M1) using low-intensity Transcranial magnetic stimulation (TMS). We hypothesised that both visual motoneurons and kinaesthetic motoneurons enhance the excitability of motor responses. We found that passive wrist movements increase the motor excitability, suggesting that kinaesthetic motoneurons do exist. The kinaesthetic influence on the motor threshold was even stronger than the visual information. Moreover, the simultaneous visual and passive kinaesthetic information increased the cortical excitability more than each of them independently. Thus, for the first time, we found evidence for the integration of passive kinaesthetic- and visual-sensory stimuli.

German version of the Chedoke McMaster arm and hand activity inventory (CAHAI-G): intra-rater reliability and responsiveness.

BACKGROUND: The English version of the Chedoke Arm and Hand Activity Inventory is a validated, upper-limb measure with the purpose of assessing functional recovery of the arm and hand after a stroke. A German translation and cross-cultural adaptation was recently produced and demonstrated high validity, inter-rater reliability and internal consistency. As a follow-up, the present study evaluated the intra-rater reliability and responsiveness of the CAHAI-G for the long and all shortened versions. METHODS: The CAHAI-G and the Action Research Arm Test were assessed on three different measurement events: upon entry (ME1), two to 3 days after entry (ME2), and after three to 4 weeks (ME3). For the intra-rater reliability analysis, the ME1 CAHAI assessments were recorded on video and rated by three therapists to obtain the intraclass coefficients (ICC). The data of all three MEs were analysed in a group of stroke inpatients for the evaluation of responsiveness. To test for responsiveness, the CAHAI-G change data were compared to concurrent instruments: The Global Rating of Change-questionnaire and the Global Rating of Concept-questionnaire. Both served as external criteria. For all CAHAI-G versions (7, 8, 9 or 13 items), the same analysis procedures for the evaluation of the responsiveness parameter were performed. RESULTS: In total, 27 patients (9 females, age 63 ± 13.7) were enrolled in the study. The ICCs for the intra-rater reliability were calculated to be between 0.988 and 0.998 for all CAHAI versions. Responsiveness parameters were as follows from CAHAI-G 7 to 13: Minimal Detectable Change (MDC90) 5.3, 6.0, 6.1, 8.2; Pearson's correlation coefficients CAHAI-Gs with ARAT 0.365, 0.409*, 0.500**, 0.597**. The Area und Under the Curve and the Minimal Clinical Important Difference values for all CAHAI-G versions and the three external criteria ranged between 0.483 to 0.603 and 2.5 to 9.0, respectively. CONCLUSION: In addition to the high validity, inter-rater reliability and internal consistency, the CAHAI-G revealed high intra-rater reliability. The data also suggest an adequate responsiveness of the CAHAI-G versions 9 and 13.

Repetitive Peripheral Magnetic Nerve Stimulation (rPMS) as Adjuvant Therapy Reduces Skeletal Muscle Reflex Activity.

Background: The reduction of muscle hypertonia and spasticity, as well as an increase in mobility, is an essential prerequisite for the amelioration of physiotherapeutical treatments. Repetitive peripheral magnetic nerve stimulation (rPMS) is a putative adjuvant therapy that improves the mobility of patients, but the underlying mechanism is not entirely clear. Methods: Thirty-eight participants underwent either an rPMS treatment (N = 19) with a 5 Hz stimulation protocol in the posterior tibial nerve or sham stimulation (N = 19). The stimulation took place over 5 min. The study was conducted in a pre-test post-test design with matched groups. Outcome measures were taken at the baseline and after following intervention. Results: The primary outcome was a significant reduction of the reflex activity of the soleus muscle, triggered by a computer-aided tendon-reflex impact. The pre-post differences of the tendon reflex response activity were -23.7% (P < 0.001) for the treatment group. No significant effects showed in the sham stimulation group. Conclusion: Low-frequency magnetic stimulation (5 Hz rPMS) shows a substantial reduction of the tendon reflex amplitude. It seems to be an effective procedure to reduce muscular stiffness, increase mobility, and thus, makes the therapeutic effect of neuro-rehabilitation more effective. For this reason, the 5 Hz rPMS treatment might have the potential to be used as an adjuvant therapy in the rehabilitation of gait and posture control in patients suffering from limited mobility due to spasticity. The effect observed in this study should be investigated conjoined with the presented method in patients with impaired mobility due to spasticity.

EMG Muscle Activation Pattern of Four Lower Extremity Muscles during Stair Climbing, Motor Imagery, and Robot-Assisted Stepping: A Cross-Sectional Study in Healthy Individuals.

BACKGROUND: Stair climbing can be a challenging part of daily life and a limiting factor for social participation, in particular for patients after stroke. In order to promote motor relearning of stair climbing, different therapeutical measures can be applied such as motor imagery and robot-assisted stepping therapy. Both are common therapy measures and a positive influence on the rehabilitation process has been reported. However, there are contradictory results regarding the neuromuscular effect of motor imagery, and the effect of robot-assisted tilt table stepping on the EMG activation compared to stair climbing itself is not known. Thus, we investigated the EMG activity during (1) a stepping task on the robot-assisted tilt table Erigo, (2) motor imagery of stair climbing, and (3) real stair climbing in healthy individuals for a subsequent study on patients with lower limb motor impairment. The aim was to assess potential amplitude independent changes of the EMG activation as a function of the different conditions. METHODS: EMG data of four muscles of the dominant leg were recorded in m. rectus femoris, m. biceps femoris, m. tibialis anterior, and m. gastrocnemius medialis. The cross-correlation analysis was performed to measure similarity/dissimilarity of the EMG curves. RESULTS: The data of the study participants revealed high cross-correlation coefficients comparing the EMG activation modulation of stair climbing and robot-assisted tilt table stepping in three muscles except for the m. gastrocnemius medialis. As the EMG activation amplitude did not differ between motor imagery and the resting phase the according EMG data of the motor imagery condition were not subjected to a further analysis. CONCLUSION: Robot-assisted tilt table stepping, but rather not motor imagery, evokes a similar activation in certain leg muscles compared to real stair climbing.

Fertilizer properties of ash from corn-stover pellets using the sequential extraction and matrix expression.

In order to get sufficient information on biomass ash for its fertilizer application, sequential extraction method was adopted for its measurement and appropriate solvents were selected to embody its nutrition characteristics. A matrix was proposed to describe the mobility of nutrients in the ash. Based on this, fertilizer property of the ash from corn-stover pellets burnt at different temperatures in a tube furnace was measured and analyzed. The identification and comparison of fertilizer properties were demonstrated. Experimental results showed that the effect of temperature on the solubility of metallic nutrients was more significant than that of non-metallic nutrients. Coarse calculation showed that there is a great potential in balancing nutrients for farmland via recycling ash from corn-stover pellets burnt at low temperature. The method and the result provide a reference for applications of ash as fertilizer.

Using an interactive virtual environment to integrate a digital Action Research Arm Test, motor imagery and action observation to assess and improve upper limb motor function in patients with neuromuscular impairments: a usability and feasibility study protocol.

INTRODUCTION: In the recent past, training systems using an interactive virtual environment have been introduced to neurorehabilitation. Such systems can be applied to encourage purposeful limb movements and will increasingly be used at home by the individual patient. Therefore, an integrated valid and reliable assessment tool on the basis of such a system to monitor the recovery process would be an essential asset. OBJECTIVES: The aim of the study is to evaluate usability, feasibility and validity of the digital version of the Action Research Arm Test using the Bi-Manu-Trainer system as a platform. Additionally, the feasibility and usability of the implementation of action observation and motor imagery tasks into the Bi-Manu-Trainer software will be evaluated. PATIENTS AND METHODS: This observational study is planned as a single-arm trial for testing the new assessment and the action observation and motor imagery training module. Therefore, 75 patients with Parkinson's disease, multiple sclerosis, stroke, traumatic brain injury or Guillain-Barré syndrome will be included. 30 out of the 75 patients will additionally take part in a 4-week training on the enhanced Bi-Manu-Trainer system. Primary outcomes will be the score on the System Usability Scale and the correlation between the conventional and digital Action Research Arm Test scores. Secondary outcomes will be hand dexterity, upper limb activities of daily living and quality of life. HYPOTHESIS: We hypothesise that the digital Action Research Arm Test assessment is a valid and essential tool and that it is feasible to incorporate action observation and motor imagery into Bi-Manu-Trainer practice. The results are expected to give recommendations for necessary modifications and might also contribute knowledge concerning the application of action observation and motor imagery tasks using a training system such as the Bi-Manu-Trainer. TRIAL REGISTRATION NUMBER: NCT03268304; Pre-results.

Motor-Evoked Potentials in the Lower Back Are Modulated by Visual Perception of Lifted Weight.

Facilitation of the primary motor cortex (M1) during the mere observation of an action is highly congruent with the observed action itself. This congruency comprises several features of the executed action such as somatotopy and temporal coding. Studies using reach-grasp-lift paradigms showed that the muscle-specific facilitation of the observer's motor system reflects the degree of grip force exerted in an observed hand action. The weight judgment of a lifted object during action observation is an easy task which is the case for hand actions as well as for lifting boxes from the ground. Here we investigated whether the cortical representation in M1 for lumbar back muscles is modulated due to the observation of a whole-body lifting movement as it was shown for hand action. We used transcranial magnetic stimulation (TMS) to measure the corticospinal excitability of the m. erector spinae (ES) while subjects visually observed the recorded sequences of a person lifting boxes of different weights from the floor. Consistent with the results regarding hand action the present study reveals a differential modulation of corticospinal excitability despite the relatively small M1 representation of the back also for lifting actions that mainly involve the lower back musculature.

Observing a movement correction during walking affects evoked responses but not unperturbed walking.

Seeing an action activates neurons in the premotor, motor, and somatosensory cortex. Since a significant fraction of these pyramidal neurons project to the spinal motor circuits, a central question is why we do not automatically perform the actions that we see. Indeed, seeing an action increases both cortical and spinal excitability of consistent motor patterns that correspond to the observed ones. Thus, it is believed that such imitative motor patterns are either suppressed or remain at a sub-threshold level. This would predict, however, that seeing someone make a corrective movement while one is actively involved in the same action should either suppress evoked responses or suppress or modulate the action itself. Here we tested this prediction, and found that seeing someone occasionally stepping over an obstacle while walking on a treadmill did not affect the normal walking pattern at all. However, cutaneously evoked reflexes in the anterior tibial and soleus muscles were modulated as if the subject was stepping over an obstacle. This result thus indicates that spinal activation was not suppressed and was neither at sub-threshold motor resonance. Rather, the spinal modulation from observed stepping reflects an adaptive mechanism for regulating predictive control mechanisms. We conclude that spinal excitability during action observation is not an adverse side-effect of action understanding but reflects adaptive and predictive motor control.