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Background: Effective science-based motor rehabilitation requires high volume of individualized, intense physical training, which can be difficult to achieve exclusively through physical 1-on-1 sessions with a therapist. Home-based training, enhanced by technological solutions, could be a tool to help facilitate the important factors for neuroplastic motor improvements. Objectives: This review aimed to discover how the inclusion of modern information and communications technology in home-based training programs can promote key neuroplastic factors associated with motor learning in neurological disabilities and identify which challenges are still needed to overcome. Methods: We conducted a thorough literature search on technological home-based training solutions and categorized the different fundamental approaches that were used. We then analyzed how these approaches can be used to promote certain key factors of neuroplasticity and which challenges still need to be solved or require external personalized input from a therapist. Conclusions: The technological approaches to home-based training were divided into three categories: sensory stimuli training, digital exchange of information training, and telerehabilitation. Generally, some technologies could be characterized as easily applicable, which gave the opportunity to promote flexible scheduling and a larger overall training volume, but limited options for individualized variation and progression. Other technologies included individualization options through personalized feedback that might increase the training effect, but also increases the workload of the therapist. Further development of easily applicable and intelligent solutions, which can return precise feedback and individualized training suggestions, is needed to fully realize the potential of home-based training in motor learning activities.

OBJECTIVE: To investigate whether nonsurgical treatment can reduce muscle contractures in individuals with neurologic disorders. The primary outcome measure was muscle contractures measured as joint mobility or passive stiffness.DATA SOURCES: Embase, MEDLINE, Cumulative Index to Nursing and Allied Health, and Physiotherapy Evidence Database in June-July 2019 and again in July 2020.STUDY SELECTION: The search resulted in 8020 records, which were screened by 2 authors based on our patient, intervention, comparison, outcome criteria. We included controlled trials of nonsurgical interventions administered to treat muscle contractures in individuals with neurologic disorders.DATA EXTRACTION: Authors, participant characteristics, intervention details, and joint mobility/passive stiffness before and after intervention were extracted. We assessed trials for risk of bias using the Downs and Black checklist. We conducted meta-analyses investigating the short-term effect on joint mobility using a random-effects model with the pooled effect from randomized controlled trials (RCTs) as the primary outcome. The minimal clinically important effect was set at 5°.DATA SYNTHESIS: A total of 70 trials (57 RCTs) were eligible for inclusion. Stretch had a pooled effect of 3° (95% CI, 1-4°; prediction interval (PI)=-2 to 7°; I 2=66%; P<.001), and robot-assisted rehabilitation had an effect of 1 (95% CI, 0-2; PI=-8 to 9; I 2=73%; P=.03). We found no effect of shockwave therapy (P=.56), physical activity (P=.27), electrical stimulation (P=.11), or botulinum toxin (P=.13). Although trials were generally of moderate to high quality according to the Downs and Black checklist, only 18 of the 70 trials used objective measures of muscle contractures. In 23 trials, nonobjective measures were used without use of assessor-blinding.CONCLUSIONS: We did not find convincing evidence supporting the use of any nonsurgical treatment option. We recommend that control

Aim: To relate quantitative magnetic resonance imaging (MRI) of ankle plantar flexor muscles to clinical functional tests in adults with cerebral palsy (CP) and neurologically intact (NI) adults. Methods: Eleven adults with CP (aged 41 ± 12, GMFCS level I-II) and 11 NI adults (aged 35 ± 10) participated in this case-control study. We used MRI to assess muscle volume and composition of the triceps surae muscles. We quantified muscle function as maximal voluntary plantarflexion (MVC) torque and countermovement jump (CMJ) height. Results: Compared to NI adults, the MRI intramuscular fat fraction estimate was significantly higher and MRI muscle volume and functional abilities (MVC and CMJ) significantly lower in adults with CP. In NI adults, but not adults with CP, MRI muscle volume correlated significantly with MVC and CMJ. In adults with CP, the estimate of intramuscular fat levels correlated significantly with jump height in a CMJ. Discussion: This study shows reduced muscle volume and altered muscle composition in adults with CP. Muscle composition appears to provide a better marker than muscle volume of reduced muscle function and impaired performance in this population. Measurements of muscle composition could be used in the assessment of neuromuscular impairments and in the determination of rehabilitation protocols in individuals with neurological disorders.

Background: An early diagnosis of chronic disability, such as risk of Cerebral Palsy (CP), is likely to affect the quality of parent-infant interactions by affecting both infant and parental factors. Due to adverse perinatal events, infants at high risk of CP may exhibit less engagement in interactions, while parents may experience increased mental health problems and disrupted parental representations that can have a negative effect on parental sensitivity. Recent clinical guidelines on early intervention among families with infants at risk of CP recommends supporting parental sensitivity and mutual enjoyable interactions more research is needed to inform such interventions. This includes understanding how infant and parental risk as well as resilience factors impact parent-infant interactions and how existing parenting programs developed among typical developing infants should be adapted to families with infants at risk of CP. In addition, as majority of research on infant neurohabilitation focus on improving motor and cognitive outcomes research on infant emotional development is needed. The study aim is to assess the quality of early parent-infant interactions in families with high-risk infants, compared to families with low-risk infants, and to explore how interaction quality is affected by infant and parental factors. Three potential mediating factors explaining the association between CP risk and less optimal parent-infant interactions will be explored: infant interactional capacities, parental mental health and well-being, and parents' representations of their child. Methods: The prospective, longitudinal design will follow infants at high risk for CP and their parents and a control group at three time points from 15 weeks to 15 months corrected infant age (CA). Measures comprise infant developmental assessments, questionnaires and interviews with both parents, and global ratings of video-recorded parent-infant interactions. Discussion: Study results will

Introduction Contractures are frequent causes of reduced mobility in children with cerebral palsy (CP) already at the age of 2-3 years. Reduced muscle use and muscle growth have been suggested as key factors in the development of contractures, suggesting that effective early prevention may have to involve stimuli that can facilitate muscle growth before the age of 1 year. The present study protocol was developed to assess the effectiveness of an early multicomponent intervention, CONTRACT, involving family-oriented and supervised home-based training, diet and electrical muscle stimulation directed at facilitating muscle growth and thus reduce the risk of contractures in children at high risk of CP compared with standard care. Methods and analysis A two-group, parallel, open-label randomised clinical trial with blinded assessment (n=50) will be conducted. Infants diagnosed with CP or designated at high risk of CP based on abnormal neuroimaging or absent fidgety movement determined as part of General Movement Assessment, age 9-17 weeks corrected age (CA) will be recruited. A balanced 1:1 randomisation will be made by a computer. The intervention will last for 6 months aiming to support parents in providing daily individualised, goal-directed activities and primarily in lower legs that may stimulate their child to move more and increase muscle growth. Guidance and education of the parents regarding the nutritional benefits of docosahexaenic acid (DHA) and vitamin D for the developing brain and muscle growth will be provided. Infants will receive DHA drops as nutritional supplements and neuromuscular stimulation to facilitate muscle growth. The control group will receive standard care as offered by their local hospital or community. Outcome measures will be taken at 9, 12, 18, 24, 36 and 48 months CA. Primary and secondary outcome measure will be lower leg muscle volume and stiffness of the triceps surae musculotendinous unit together with infant motor profile, respe

Background: CNS lesions that are acquired early in life e.g. cerebral palsy (CP) disturb muscle development and growth, while CNS injuries acquired later in life e.g. stroke, affect fully matured muscles and cause paresis and atrophy. These differences may result in different contracture phenotypes. Aim: The purpose of this study was to compare systemic biomarkers and gene expression levels in muscle of individuals with CNS lesions acquired early and later in life. Methods: Blood samples and muscle biopsies were analyzed using Enzyme-linked immunosorbent assay and Real-time PCR from n = 24 control participants, n = 14 individuals with cerebral palsy, and n = 12 stroke survivors. Results: Systemic markers: Myostatin was significant-ly decreased in both the cerebral palsy (p = 0.0051), and the stroke group (p = 0.036). Creatine Kinase-MB and C-Reactive Protein were significantly ele-vated in stroke patients only (p < 0.007 & p > 0.034 respectively). Gene ex-pressions: The expression of myostatin (MSTN) was significantly lower in both the ST and the CP group when compared to Ctrl (p = 0.02). In addition, collagen type 4A1 (COL4A1) was significantly lower in the CP group com-pared to the other groups (p = 0.015). Finally, the troponin 1 slow skeletal muscle type was significantly increased in the ST group when compared to both CP and Ctrl (p = 0.03). Conclusion: The downregulation of myostatin in individuals with both early and late CNS injury is likely a compensatory reaction to muscle weakness, reduced muscle mass and/or muscle atrophy. Changes in gene expression may reflect a specific alteration depending on when in life the CNS lesions were acquired. (PDF) Cerebral Palsy and Stroke—Early and Late Brain Lesion Present Differences in Systemic Biomarkers and Gene Expression Related to Muscle Contractures. Available from: https://www.researchgate.net/publication/349557094_Cerebral_Palsy_and_Stroke-Early_and_Late_Brain_Lesion_Present_Differences_in_Systemic_Bio

BACKGROUND: Cerebral palsy (CP) is a neurodevelopmental disturbance characterized by impaired control of movement. Function often decreases and 15% of adults are classified as severely affected (Gross Motor Function Classification Scale III-V). Little is known about interventions that aim to improve functional abilities in this population.OBJECTIVE: To evaluate a 12-week intervention based on motor learning principles on functional ability in adults with severe CP.METHODS: 16 adults (36±10 years, GMFCS III-V) were enrolled and divided into an intervention group (Active group) and a standard care group (Control group). Primary outcome measure was Gross Motor Function Measure (GMFM-88). Secondary measures were neurological status. The Active group were measured at baseline, after the intervention and at one-month follow-up. The Control group were measured at baseline and after one month.RESULTS: Analysis showed statistically significant improvement in GMFM-88 for the Active group from baseline to post assessment compared with the Control group (group difference: 5 points, SE 14.5, p = 0.008, CI: 1.2 to 8.7). Improvements were maintained at follow-up. Results from the neurological screening showed no clear tendencies.CONCLUSIONS: The study provides support that activities based on motor learning principles may improve gross motor function in adults with severe CP.

Hyperexcitable stretch reflexes are often not present despite of other signs of spasticity in people with brain lesion. Here we looked for evidence that increased resistance to length change of the plantar flexor muscle-fascicles may contribute to a reduction in the stretch reflex response in adults with cerebral palsy (CP). A total of 17 neurologically intact (NI) adults (mean age 36.1; 12 female) and 13 ambulant adults with CP (7 unilateral; mean age 33.1; 5 female) participated in the study. Subjects were seated in a chair with the examined foot attached to a foot plate, which could be moved by a computer-controlled electromotor. An ultrasound probe was placed over the medial aspect of the leg to measure the length of medial gastrocnemius muscle fascicles. Slow (7 deg/s) and fast (200 deg/s) stretches with amplitude 6 deg of the plantar flexors were applied over an ankle range of 70 deg at 10 deg intervals between 60 and 130 deg plantarflexion. It was checked by EMG electrodes that the slow stretches were sufficiently slow not to elicit any activity and that the fast stretches were sufficiently quick to elicit a maximal stretch reflex in both groups. The torque elicited by the stretches was measured together with changes in the length of medial gastrocnemius muscle fascicles. Muscle fascicles increased significantly in length with increasing dorsiflexion position in both populations (p <0.001), but the fascicles were shorter in the CP population at all positions. Slow stretches elicited significantly larger torque and significantly smaller length change of muscle fascicles as the ankle joint position was moved more towards dorsiflexion in CP than in NI (p <0.001). Fast stretches elicited larger torque responses at ankle joint positions of 80-100 deg in the NI than in the CP group (p <0.01). A significant negative correlation was observed between the torque response and muscle fascicle length change to slow stretch in CP (p <0.05), but not in NI. Th

OBJECTIVE: Task-specific training is often used in functional rehabilitation for its potential to improve performance at locomotor tasks in neurological populations. As push-off impairment are often seen with these patients, this functional approach shows potential to retrain gait overground to normalize the gait pattern and retrain the ability to improve gait speed. The main objective of this project was to validate, in healthy participants, a simple, low-cost push-off retraining protocol based on task-specific training that could be implemented during overground walking in the clinic.METHODS: 30 healthy participants walked in an 80-meter long corridor before, during, and after the application of an elastic resistance to the right ankle. Elastic tubing attached to the front of a modified ankle-foot orthosis delivered the resistance during push-off. Relative ankle joint angular displacements were recorded bilaterally and continuously during each walking condition.RESULTS: On the resisted side, participants presented aftereffects (increased peak plantarflexion angle from 13.4±4.2° to 20.0±6.4°, p<0.0001 and increased peak plantarflexion angular velocity from 145.8±22.7°/s to 174.4±37.4°/s, p<0.0001). On the non-resisted side, aftereffects were much smaller than on the resisted side suggesting that the motor learning process was mainly specific to the trained leg.CONCLUSION: This study shows the feasibility of modifying push-off kinematics using an elastic resistance applied at the ankle while walking overground. This approach represents an interesting venue for future gait rehabilitation.

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper presents an adaptive control-based strategy to regulate the output voltage of a a magnetically coupled multiport dc-dc converter aimed at automotive applications. The proposed algorithm renders robustness to resistive load uncertainty and to the presence of unknown constant power loads. The theoretical analysis, which uses Lyapunov stability theory, is validated via realistic numerical simulations., Postprint (author's final draft)

For the audiological assessment of the speech-in-noise abilities of children with normal or impaired hearing, appropriate test materials are required. However, in Denmark, no standardized materials exist. The purpose of this study was to develop a Danish sentence corpus suitable for testing school-age children. Based on the 600 validated test sentences from the Danish DAT (Dagmar, Asta, or Tine) corpus, 11 test lists comprising 20 sentences each were carefully constructed. These lists were evaluated in terms of their perceptual similarity and reliability with a group of 20 typically developing, normal-hearing children aged 6 to 12 years. Using stationary speech-shaped noise and diotic stimulus presentation, speech recognition thresholds (SRTs) were measured twice per list and participant at two separate visits. The analyses showed that six test lists were perceptually equivalent. These lists are characterized by a grand average SRT of −2.6 dB signal-to-noise ratio, a test–retest improvement of 0.6 dB, and a within-subject standard deviation of 1.1 dB signal-to-noise ratio. The other lists were characterized by slightly higher SRTs, slightly larger training effects, and slightly larger measurement uncertainty, but were otherwise also usable. Overall, it is therefore concluded that the developed corpus is suited for assessing speech recognition in noise in Danish 6- to 12-year olds. The corpus is publicly available.

Consolidation leading to retention of motor memory following motor practice involves activity-dependent plastic processes in the corticospinal system. To investigate whether beta-band transcranial alternating current stimulation (tACS) applied immediately following skill acquisition can enhance ongoing consolidation processes and thereby motor skill retention 20 adults participated in a randomized, double-blinded, sham-controlled study. Participants received tACS at peak beta-band corticomuscular coherence (CMC) frequency or sham tACS for 10 min following practice of a visuomotor ankle dorsiflexion task. Performance was measured as the average percentage time on target. Electroencephalograhy (EMG) was measured at Cz and EMG from the right tibialis anterior muscle. CMC and intramuscular coherence (IMC) were estimated during 2-min tonic dorsiflexion. Motor skill retention was tested 1 and 7 days after motor practice. From the end of motor practice to the retention tests, motor performance improved more in the tACS group compared with the sham tACS group after 1 (P = 0.05) and 7 days (P < 0.001). At both retention tests, beta-band IMC increased in the tACS group compared with post-tACS. Beta-band CMC increased in the tACS group at retention day 1 compared with post-tACS. Changes in CMC but not IMC were correlated with performance 1 and 7 days following practice. This study shows that tACS applied at beta-band CMC frequency improves consolidation following visuomotor practice and increases beta-band CMC and IMC. We propose that oscillatory beta activity in the corticospinal system may facilitate consolidation of the motor skill.

Optimization of motor performance is of importance in daily life, in relation to recovery following injury as well as for elite sports performance. The present study investigated whether transcutaneous spinal direct current stimulation (tsDCS) may enhance voluntary ballistic activation of ankle muscles and descending activation of spinal motor neurons in able-bodied adults. Forty-one adults (21 men; 24.0 ± 3.2 years) participated in the study. The effect of tsDCS on ballistic motor performance and plantar flexor muscle activation was assessed in a double-blinded sham-controlled cross-over experiment. In separate experiments, the underlying changes in excitability of corticospinal and spinal pathways were probed by evaluating soleus (SOL) motor evoked potentials (MEPs) following single-pulse transcranial magnetic stimulation (TMS) over the primary motor cortex, SOL H-reflexes elicited by tibial nerve stimulation and TMS-conditioning of SOL H-reflexes. Measures were obtained before and after cathodal tsDCS over the thoracic spine (T11-T12) for 10 min at 2.5 mA. We found that cathodal tsDCS transiently facilitated peak acceleration in the ballistic motor task compared to sham tsDCS. Following tsDCS, SOL MEPs were increased without changes in H-reflex amplitudes. The short-latency facilitation of the H-reflex by subthreshold TMS, which is assumed to be mediated by the fast conducting monosynaptic corticomotoneuronal pathway, was also enhanced by tsDCS. We argue that tsDCS briefly facilitates voluntary motor output by increasing descending drive from corticospinal neurones to spinal plantar flexor motor neurons. tsDCS can thus transiently promote within-session CNS function and voluntary motor output and holds potential as a technique in the rehabilitation of motor function following central nervous lesions.

Plastic adaptations are known to take place in muscles, tendons, joints and the nervous system in response to changes in muscle activity. However, few studies have addressed how these plastic adaptations are related. Thus, this study focuses on changes in the mechanical properties of the ankle plantarflexor muscle-tendon unit, stretch reflex activity and spinal neuronal pathways in relation to cast immobilization. The left rat hindlimb from toes to hip was immobilized with a plaster cast for 1, 2, 4 or 8 weeks followed by acute electrophysiological recordings to investigate muscle resistance and stretch reflex torque. Moreover, additional acute experiments were performed after 4 weeks of immobilization to investigate changes in the central gain of the stretch reflex. Monosynaptic reflexes (MSR) were recorded from the L4 and L5 ventral roots following stimulation of the corresponding dorsal roots. Rats developed reduced range of movement in the ankle joint 2 weeks after immobilization. This was accompanied by significant increases in the stiffness of the muscle-tendon complex at 4 and 8 weeks following immobilization. Stretch reflexes were absent in all rats at 4-8 weeks following immobilization. This was associated with increased central gain of the stretch reflex. These data show that numerous inter-related plastic changes occur in muscles, connective tissue and the central nervous system in response to changes in muscle use. The findings provide understanding of coordinated adaptations in multiple tissues and have important implications for prevention and treatment of the negative consequences of immobilization following injuries of the nervous and musculoskeletal systems.

Spastic movement disorder is characterized by reduced ability to selectively activate muscles with significant co-activation of antagonist muscles. It has traditionally been thought that hyperexcitable stretch reflexes have a central role in the pathophysiology and the clinical manifestations of the disorder. Here we argue that the main functional challenges for persons with spastic movement disorder are related to contractures, paresis, weak muscles and inappropriate central motor commands, whereas hyperexcitable reflexes play no or only an insignificant functional role. Co-activation of antagonist muscles and stiff posture and gait may rather be adaptations that aim to ensure joint and postural stability due to insufficient muscle strength. Aberrant (involuntary) muscle activity is likely related to an inadequate prediction of the sensory consequences of movement and a resulting impairment of muscle coordination. We argue that improvement of functional muscle strength and muscle coordination following central motor lesions may be achieved by optimizing integration of somatosensory information into central feedforward motor programs, whereas anti-spastic therapy that aims to reduce reflex activity may be less efficient. This opens for novel investigations into new treatment strategies that may improve functional control of movement and prevent reduced joint mobility in people with brain lesions.