A six degrees-of-freedom cable-driven robotic platform for head-neck movement.

This paper introduces a novel cable-driven robotic platform that enables six degrees-of-freedom (DoF) natural head-neck movements. Poor postural control of the head-neck can be a debilitating symptom of neurological disorders such as amyotrophic lateral sclerosis and cerebral palsy. Current treatments using static neck collars are inadequate, and there is a need to develop new devices to empower movements and facilitate physical rehabilitation of the head-neck. State-of-the-art neck exoskeletons using lower DoF mechanisms with rigid linkages are limited by their hard motion constraints imposed on head-neck movements. By contrast, the cable-driven robot presented in this paper does not constrain motion and enables wide-range, 6-DoF control of the head-neck. We present the mechatronic design, validation, and control implementations of this robot, as well as a human experiment to demonstrate a potential use case of this versatile robot for rehabilitation. Participants were engaged in a target reaching task while the robot applied both assistive and resistive moments on the head during the task. Our results show that neck muscle activation increased by 19% when moving the head against resistance and decreased by 28-43% when assisted by the robot. Overall, these results provide a scientific justification for further research in enabling movement and identifying personalized rehabilitation for motor training. Beyond rehabilitation, other applications such as applying force perturbations on the head to study sensory integration and applying traction to achieve pain relief may benefit from the innovation of this robotic platform which is capable of applying controlled 6-DoF forces/moments on the head.

Irregularity of instantaneous gamma frequency in the motor control network characterize visuomotor and proprioceptive information processing.

Objective.The study aims to characterize movements with different sensory goals, by contrasting the neural activity involved in processing proprioceptive and visuo-motor information. To accomplish this, we have developed a new methodology that utilizes the irregularity of the instantaneous gamma frequency parameter for characterization.Approach.In this study, eight essential tremor patients undergoing an awake deep brain stimulation implantation surgery repetitively touched the clinician's finger (forward visually-guided/FV movement) and then one's own chin (backward proprioceptively-guided/BP movement). Neural electrocorticographic recordings from the motor (M1), somatosensory (S1), and posterior parietal cortex (PPC) were obtained and band-pass filtered in the gamma range (30-80 Hz). The irregularity of the inter-event intervals (IEI; inverse of instantaneous gamma frequency) were examined as: (1) auto-information of the IEI time series and (2) correlation between the amplitude and its proceeding IEI. We further explored the network connectivity after segmenting the FV and BP movements by periods of accelerating and decelerating forces, and applying the IEI parameter to transfer entropy methods.Main results.Conceptualizing that the irregularity in IEI reflects active new information processing, we found the highest irregularity in M1 during BP movement, highest in PPC during FV movement, and the lowest during rest at all sites. Also, connectivity was the strongest from S1 to M1 and from S1 to PPC during FV movement with accelerating force and weakest during rest.Significance. We introduce a novel methodology that utilize the instantaneous gamma frequency (i.e. IEI) parameter in characterizing goal-oriented movements with different sensory goals, and demonstrate its use to inform the directional connectivity within the motor cortical network. This method successfully characterizes different movement types, while providing interpretations to the sensory-motor integration processes.

The shoulder joint complex in the throwing motion.

The shoulder joint complex in the overhead athlete is organized to effectively transfer the proximally generated forces distally into the arm. The organization also protects the joints and anatomic structures against the repetitive high velocities, large ranges of motions, and compressive, shear, translational, and distraction loads in the overhead motion while placing the hand in the "launch window." Coupling of the movements of the scapula, clavicle, and humerus results in scapulohumeral rhythm (SHR). Effective SHR requires the clavicle and scapula-and, at times, the mechanically linked claviscapular segment-to move the arm into the task-specific position and motion and requires the humerus to move through the ranges of motion to achieve the specific task in the throwing motion. Alterations in SHR can negatively affect effective shoulder joint complex function in the overhead throwing motion and increase injury risk. There are 4 phases of clavicular, scapular, and claviscapular motion that are coupled with arm motion in SHR. The first 3 phases occur in arm elevation motions from 0°-90° and result in the claviscapula and humerus being placed in task-specific positions. The fourth phase is coupling of claviscapular motion with humeral motion to maintain ball-and-socket kinematics throughout the throwing motion. Alterations in this composite motion are termed "scapular dyskinesis." The dyskinesis is considered an impairment of the efficient mobility of the claviscapular segment of the shoulder complex. The most prevalent problem with scapular dyskinesis is the association of scapular protraction and consequent glenoid antetilt with alterations in humeral rotation and posterior humeral head translation to produce shoulder joint internal impingement. Task effectiveness in overhead throwing is also based on and determined by humeral range of motion, precision of humeral motion, and velocity of humeral motion, as well as humeral and arm position in 3-dimensional space. This activity requires maximum ball-and-socket kinematics to create the highest amount of concavity-compression that creates stability for the joint. There are bony and soft-tissue contributions to this stability. Injuries to the glenoid labrum are among the most common deficits that alter concavity-compression. Clinical evaluation of the shoulder joint complex in the injured throwing athlete should be comprehensive and systematic, following an evaluation pathway for proximal and distal causative factors and including observation of humeral motion. This type of evaluation can result in intervention protocols that address the pathoanatomic, pathophysiological, and pathomechanical deficits identified.

Comparison of Spectral Analysis of Gamma Band Activity During Actual and Imagined Movements as a Cognitive Tool.

Background. Imagined motor movement is a cognitive process in which a subject imagines a movement without doing it, which activates similar brain regions as during actual motor movement. Brain gamma band activity (GBA) is linked to cognitive functions such as perception, attention, memory, awareness, synaptic plasticity, motor control, and Imagination. Motor imagery can be used in sports to improve performance, raising the possibility of using it as a rehabilitation method through brain plasticity through mirror neurons. Method. A comparative observational study was conducted on 56 healthy male subjects after obtaining clearance from the Ethics Committee. EEG recordings for GBA were taken for resting, real, and imaginary motor movements and compared. The power spectrum of gamma waves was analyzed using the Kruskal-Wallis test; a p-value <.05 was considered significant. Results. The brain gamma rhythm amplitude was statistically increased during both actual and imaginary motor movement compared to baseline (resting stage) in most of the regions of the brain except the occipital region. There was no significant difference in GBA between real and imaginary movements. Conclusions. Increased gamma rhythm amplitude during both actual and imaginary motor movement than baseline (resting stage) indicating raised brain cognitive activity during both types of movements. There was no potential difference between real and imaginary movements suggesting that the real movement can be replaced by the imaginary movement to enhance work performance through mirror therapy.

Electrospinography for non-invasively recording spinal sensorimotor networks in humans.

Objective. Currently, few non-invasive measures exist for directly measuring spinal sensorimotor networks. Electrospinography (ESG) is one non-invasive method but is primarily used to measure evoked responses or for monitoring the spinal cord during surgery. Our objectives were to evaluate the feasibility of ESG to measure spinal sensorimotor networks by determining spatiotemporal and functional connectivity changes during single-joint movements at the spinal and cortical levels.Approach. We synchronously recorded electroencephalography (EEG), electromyography, and ESG in ten neurologically intact adults while performing one of three lower-limb tasks (no movement, plantar-flexion and knee flexion) in the prone position. A multi-pronged approach was applied for removing artifacts usingH∞filtering, artifact subspace reconstruction and independent component (IC) analysis. Next, data were segmented by task and ICs of EEG were clustered across participants. Within-participant analysis of ICs and ESG data was conducted, and ESG was characterized in the time and frequency domains. Generalized partial directed coherence analysis was performed within ICs and between ICs and ESG data by participant and task.Results.K-means clustering resulted in five clusters of ICs at Brodmann areas (BAs) 9, BA 8, BA 39, BA 4, and BA 22. Areas associated with motor planning, working memory, visual processing, movement, and attention, respectively. Time-frequency analysis of ESG data found localized changes during movement execution when compared to no movement. Lastly, we found bi-directional changes in functional connectivity (p < 0.05, adjusted for multiple comparisons) within IC's and between IC's and ESG sensors during movement when compared to the no movement condition.Significance. To our knowledge this is the first report using high density ESG for characterizing single joint lower limb movements. Our findings provide support that ESG contains information about efferent and afferent signaling in neurologically intact adults and suggests that we can utilize ESG to directly study the spinal cord.

Usefulness of thalamic beta activity for closed-loop therapy in essential tremor.

A partial loss of effectiveness of deep brain stimulation of the ventral intermediate nucleus of the thalamus (VIM) has been reported in some patients with essential tremor (ET), possibly due to habituation to permanent stimulation. This study focused on the evolution of VIM local-field potentials (LFPs) data over time to assess the long-term feasibility of closed-loop therapy based on thalamic activity. We performed recordings of thalamic LFPs in 10 patients with severe ET using the ACTIVA™ PC + S (Medtronic plc.) allowing both recordings and stimulation in the same region. Particular attention was paid to describing the evolution of LFPs over time from 3 to 24 months after surgery when the stimulation was Off. We demonstrated a significant decrease in high-beta LFPs amplitude during movements inducing tremor in comparison to the rest condition 3 months after surgery (1.91 ± 0.89 at rest vs. 1.27 ± 1.37 µV2/Hz during posture/action for N = 8/10 patients; p = 0.010), 12 months after surgery (2.92 ± 1.75 at rest vs. 2.12 ± 1.78 µV2/Hz during posture/action for N = 7/10 patients; p = 0.014) and 24 months after surgery (2.32 ± 0.35 at rest vs 0.75 ± 0.78 µV2/Hz during posture/action for 4/6 patients; p = 0.017). Among the patients who exhibited a significant decrease of high-beta LFP amplitude when stimulation was Off, this phenomenon was observed at least twice during the follow-up. Although the extent of this decrease in high-beta LFPs amplitude during movements inducing tremor may vary over time, this thalamic biomarker of movement could potentially be usable for closed-loop therapy in the long term.

Robotic Brace Based Multi-Dimensional Assessment for Trunk Ability: A Preliminary Study in Patients with Spinal Cord Injury.

Evaluating trunk control ability is significant in guiding patients towards proper functional training. Most existing devices have only a singular assessment function, resulting in prolonged and asynchronous assessments. Devices with multi-dimensional assessment capabilities may address these limitations. This study utilizes a robotic brace, RoboBDsys-II, to assess the trunk ability of individuals with spinal disorders and to validate its effectiveness. The device can simultaneously collect kinematic, kinetic, and center of pressure data, reducing the assessment time and enabling the simultaneous assessment. The force platform is designed to measure the center of pressure and the force control of the parallel module is developed for the coronal movement assessment. Four patients with spinal cord injury participated in the study to assess their trunk range of motion and muscle strength. Results demonstrate that the trunk range of motion determines the center of pressure metrics in lateral bending experiments. Furthermore, RoboBDsys-II exhibits excellent test-retest reliability in lateral bending experiments and can reveal the muscle strength differences in different directions. The system has potential advantage in the trunk ability assessment.

The effects of joint hypermobility on pain and functional biomechanics in adolescents with juvenile fibromyalgia: secondary baseline analysis from a pilot randomized controlled trial.

BACKGROUND: Joint hypermobility is a common clinical finding amongst hereditary connective tissue disorders that is observed in pediatric rheumatological settings, and often associated with chronic pain. Joint hypermobility may also contribute to deficits in physical functioning and physical activity, but previous findings have been inconsistent. It is possible that physical activity impairment in joint hypermobility may be due to chronic aberrant movement patterns subsequent to increased joint laxity. METHOD: As part of a larger randomized pilot trial of juvenile onset fibromyalgia (JFM), a secondary analysis was conducted to explore whether adolescents with JFM and joint hypermobility differed from non-joint hypermobility peers in terms of pain, daily functioning, and biomechanics (i.e., kinetics and kinematics) during a moderately vigorous functional task. RESULTS: From the larger sample of adolescents with JFM (N = 36), 13 adolescents (36.1%) met criteria for joint hypermobility and 23 did not have joint hypermobility. Those with joint hypermobility exhibited poorer overall functioning (Md = 20, Q1,Q3 [5.8, 7.6] vs. Md = 29, Q1,Q3 [5.1, 7.6]) but there were no differences in pain (Md = 6.9, Q1,Q3 [22, 33], vs. Md = 6.45, Q1,Q3 [15, 29.5]). Inspection of time-series plots suggests those with joint hypermobility exhibited decreased hip flexion and frontal plane hip moment (e.g., resistance to dynamic valgus) during the landing phase (early stance) and greater hip and knee transverse plane moments during the propulsion phase (late stance) of the drop vertical jump task (DVJ). No other differences in lower extremity biomechanics were observed between study groups. CONCLUSIONS: In this exploratory study, there were small but notable differences in biomechanics between patients with JFM who also had joint hypermobility versus those without joint hypermobility during a landing and jumping task (e.g., DVJ). These differences may indicate decreased joint stiffness during landing, associated with increased joint laxity and decreased joint stability, which may put them at greater risk for injury. Further study with a larger sample size is warranted to examine whether these biomechanical differences in patients with JFM and joint hypermobility affect their response to typical physical therapy or exercise recommendations.

Persistent changes in motor adaptation strategies after perturbations that require exploration of novel muscle activation patterns.

Motor skill learning requires the acquisition of novel muscle patterns and a new control policy-a process that requires time. In contrast, motor adaptation often requires only the adjustment of existing muscle patterns-a fast process. By altering the mapping of muscle activations onto cursor movements in a myoelectrically controlled virtual environment, we are able to create perturbations that require either the recombination of existing muscle synergies (compatible virtual surgery) or the learning of novel muscle patterns (incompatible virtual surgery). We investigated whether adaptation to a compatible surgery is affected by prior exposure to an incompatible surgery, i.e., a motor skill learning task. We found that adaptation to a compatible surgery was characterized by a decrease in the quality of muscle pattern reconstructions using the original synergies and an increase in reaction times only after exposure to an incompatible surgery. In contrast, prior exposure to a compatible surgery did not affect the learning process required to overcome an incompatible surgery. The fact that exposure to an incompatible surgery had a profound effect on the muscle patterns during the adaptation to a subsequent compatible surgery and not vice versa suggests that null space exploration, possibly combined with an explicit exploration strategy, is engaged during exposure to an incompatible surgery and remains enhanced during a new adaptation episode. We conclude that motor skill learning, requiring novel muscle activation patterns, leads to changes in the exploration strategy employed during a subsequent perturbation.NEW & NOTEWORTHY Motor skill learning requires the acquisition of novel muscle patterns, whereas motor adaptation requires adjusting existing ones. We wondered whether training a new motor skill affects motor adaptation strategies. We show that learning an incompatible perturbation, a complex skill requiring new muscle synergies, affects the muscle patterns observed during adaption to a compatible perturbation, which requires adjusting the existing synergies. Our results suggest that motor skill learning results in persistent changes in the exploration strategy.

Shared Three-Dimensional Robotic Arm Control Based on Asynchronous BCI and Computer Vision.

OBJECTIVE: A brain-computer interface (BCI) can be used to translate neuronal activity into commands to control external devices. However, using noninvasive BCI to control a robotic arm for movements in three-dimensional (3D) environments and accomplish complicated daily tasks, such as grasping and drinking, remains a challenge. APPROACH: In this study, a shared robotic arm control system based on hybrid asynchronous BCI and computer vision was presented. The BCI model, which combines steady-state visual evoked potentials (SSVEPs) and blink-related electrooculography (EOG) signals, allows users to freely choose from fifteen commands in an asynchronous mode corresponding to robot actions in a 3D workspace and reach targets with a wide movement range, while computer vision can identify objects and assist a robotic arm in completing more precise tasks, such as grasping a target automatically. RESULTS: Ten subjects participated in the experiments and achieved an average accuracy of more than 92% and a high trajectory efficiency for robot movement. All subjects were able to perform the reach-grasp-drink tasks successfully using the proposed shared control method, with fewer error commands and shorter completion time than with direct BCI control. SIGNIFICANCE: Our results demonstrated the feasibility and efficiency of generating practical multidimensional control of an intuitive robotic arm by merging hybrid asynchronous BCI and computer vision-based recognition.

Robust neural decoding for dexterous control of robotic hand kinematics.

BACKGROUND: Manual dexterity is a fundamental motor skill that allows us to perform complex daily tasks. Neuromuscular injuries, however, can lead to the loss of hand dexterity. Although numerous advanced assistive robotic hands have been developed, we still lack dexterous and continuous control of multiple degrees of freedom in real-time. In this study, we developed an efficient and robust neural decoding approach that can continuously decode intended finger dynamic movements for real-time control of a prosthetic hand. METHODS: High-density electromyogram (HD-EMG) signals were obtained from the extrinsic finger flexor and extensor muscles, while participants performed either single-finger or multi-finger flexion-extension movements. We implemented a deep learning-based neural network approach to learn the mapping from HD-EMG features to finger-specific population motoneuron firing frequency (i.e., neural-drive signals). The neural-drive signals reflected motor commands specific to individual fingers. The predicted neural-drive signals were then used to continuously control the fingers (index, middle, and ring) of a prosthetic hand in real-time. RESULTS: Our developed neural-drive decoder could consistently and accurately predict joint angles with significantly lower prediction errors across single-finger and multi-finger tasks, compared with a deep learning model directly trained on finger force signals and the conventional EMG-amplitude estimate. The decoder performance was stable over time and was robust to variations of the EMG signals. The decoder also demonstrated a substantially better finger separation with minimal predicted error of joint angle in the unintended fingers. CONCLUSIONS: This neural decoding technique offers a novel and efficient neural-machine interface that can consistently predict robotic finger kinematics with high accuracy, which can enable dexterous control of assistive robotic hands.

Assembly properties of bacterial actin MreB involved in Spiroplasma swimming motility.

Bacterial actin MreB forms filaments composed of antiparallel double-stranded units. The wall-less helical bacterium Spiroplasma has five MreB homologs (MreB1-5), some of which are involved in an intracellular ribbon for driving the bacterium's swimming motility. Although the interaction between MreB units is important for understanding Spiroplasma swimming, the interaction modes of each ribbon component are unclear. Here, we examined the assembly properties of Spiroplasma eriocheiris MreB5 (SpeMreB5), one of the ribbon component proteins that forms sheets. Electron microscopy revealed that sheet formation was inhibited under acidic conditions and bundle structures were formed under acidic and neutral conditions with low ionic strength. We also used solution assays and identified four properties of SpeMreB5 bundles as follows: (I) bundle formation followed sheet formation; (II) electrostatic interactions were required for bundle formation; (III) the positively charged and unstructured C-terminal region contributed to promoting lateral interactions for bundle formation; and (IV) bundle formation required Mg2+ at neutral pH but was inhibited by divalent cations under acidic pH conditions. During these studies, we also characterized two aggregation modes of SpeMreB5 with distinct responses to ATP. These properties will shed light on SpeMreB5 assembly dynamics at the molecular level.

Mixed [Formula: see text]-synthesis tracking control and disturbance rejection in a robotic digit of an impaired human hand for anthropomorphic coordination.

In a partially impaired anthropomorphic hand, maintaining the movement coordination of the robotic digits with the central nervous system (CNS) and natural digits is crucial for robust performance. A challenge in the control perspective of movement coordination of a human hand is finding methods robust to the disturbances in a well-posed control problem of a biomechanical model. We use visco-elastic dynamics in the human palm frame of reference to explore the biomechanics of movement coordination to solve this control problem. Our biomechanical model incorporates the time delay due to actuation force, parametric uncertainty, exogenous disturbances, and sensory noise to constitute a 21-degree of freedom model. A mixed [Formula: see text]-synthesis controller, considering the real parametric uncertainty, represents the CNS in the control paradigm. We consider the robotic finger's flexion movement when perturbed from the initial equilibrium. The controller provides feedback force at the joints to regulate the robotic finger movement. The index finger follows a reference trajectory of the joint angular position profile and stabilizes at a flexion angle of 1 rad/s at a time of 1 s. The main control objective is to keep the angular displacement of the finger joint constant when a disturbance force acts. We simulate the modeling scheme in MATLAB/ Simulink. The results demonstrate that our controller scheme is robust against the worst-case disturbance and achieves the desired performance value. Developing a biologically inspired neurophysiological controller with robust performance has many applications, including assistive rehabilitation devices, hand movement disorder diagnosis, and robotic manipulators.

Effects of short-term motor training on accuracy and precision of simple jaw and finger movements after orthodontic treatment and orthognathic surgery: A case-control study.

BACKGROUND: Orthognathic surgery has been performed with increasing frequency for the treatment of severe malocclusion, yet the postsurgical neuromuscular recovery of patients has been inadequately studied. OBJECTIVE: To investigate the effect of short-term and simple jaw motor training on accuracy and precision of jaw motor control in patients following orthodontic treatment and orthognathic surgery. METHODS: Twenty patients who had completed preoperative orthodontics, 20 patients who had undergone bimaxillary orthognathic surgery and 20 age-and-gender-matched healthy controls participated in the study. Participants were asked to perform 10 continuous jaw opening and finger lifting movements before and after a 30-min motor training session. The variability in the amplitude of these simple movements was expressed as percentage in relation to the target position (accuracy - Daccu ) and as coefficient of variation (precision - CVprec ) to describe the motor performance. Furthermore, the changes in amplitude before and after training were measured in percentage. RESULTS: Daccu and CVprec of simple jaw and finger movements significantly decreased after motor training (p ≤ .018) in all groups. The relative changes in finger movements were higher than jaw movements (p < .001) but with no differences among the groups (p ≥ .247). CONCLUSION: Both accuracy and precision of simple jaw and finger movements improved after short-term motor training in all three groups, demonstrating the inherent potential for optimization of novel motor tasks. Finger movements improved more than jaw movements but with no differences between groups, suggesting that changes in occlusion and craniofacial morphology are not associated with impaired neuroplasticity or physiological adaptability of jaw motor function.

Movement technique analysis and sports injuries prevention in the elderly physical training / Análise técnica de movimento e prevenção de lesões esportivas no treinamento físico de idosos / Análisis técnico del movimiento y prevención de lesiones deportivas en el entrenamiento físico de personas mayores

ABSTRACT Introduction: Physical training for the elderly is extremely popular. However, there is a lack of analysis on sports injuries in the elderly. Objective: Study the analysis of movement in sports training techniques and preventing sports injuries in the elderly. Methods: Participating in a 15-minute running and warm-up activity before using the standard FMS test kit, they followed seven test movements, each repeated three times; they did so during six weeks of training based on the recommendations for the prevention of sports injuries presented in this paper. Results: Among the 14 elderly subjects with a total FMS score <14 points, most functional motor scores were 15-16 points, of which 19 points were high, and 9 points were low. In the intervention based on the perspective of sports injuries, the FMS measurement value of the elderly was much better than before, and the evaluation of the technical analysis of movement after the correction was significantly higher than before. Conclusion: The prevention of sports injuries proposed in this paper can effectively help the elderly to prevent sports injuries. This paper considers the FMS trial design as an example for analyzing movements in sports training of the elderly and formulating standards. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: O treinamento físico em idosos é extremamente popular, entretanto, carece de análise sobre as lesões esportivas em idosos. Objetivo: Estudar a análise do movimento nas técnicas de treinamento esportivo e a prevenção de lesões esportivas em idosos. Métodos: Participando de uma atividade de 15 minutos de corrida e aquecimento antes de utilizar o kit de teste padrão FMS, seguiram-se sete movimentos de teste, cada um deles repetidos 3 vezes; fizeram-no durante seis semanas de treinamento com base nas recomendações de prevenção de lesões esportivas apresentadas neste trabalho. Resultados: Entre os 14 sujeitos idosos com pontuação total de FMS <14 pontos, a maioria das pontuações motoras funcionais foram de 15-16 pontos, dos quais 19 pontos foram altos e 9 pontos foram baixos. Na intervenção baseada sob a ótica das lesões esportivas, o valor de medição FMS dos idosos foi muito melhor do que anteriormente, e a avaliação da análise técnica do movimento após a correção foi significativamente maior do que aquela antes da correção. Conclusão: A prevenção de lesões esportivas proposta neste trabalho pode efetivamente ajudar os idosos a prevenir as lesões esportivas. Este documento considera o projeto de ensaio do FMS como um exemplo para analisar os movimentos no treinamento esportivo das pessoas idosas e para formular padrões. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El entrenamiento físico en las personas mayores es muy popular, sin embargo, hay una falta de análisis sobre las lesiones deportivas en las personas mayores. Objetivo: Estudiar el análisis del movimiento en las técnicas de entrenamiento deportivo y la prevención de lesiones deportivas en las personas mayores. Métodos: Participando en una actividad de carrera y calentamiento de 15 minutos antes de utilizar el kit de prueba estándar de FMS, se siguieron siete movimientos de prueba, cada uno repetido 3 veces; lo hicieron durante seis semanas de entrenamiento basado en las recomendaciones para la prevención de lesiones deportivas presentadas en este trabajo. Resultados: Entre los 14 sujetos de edad avanzada con una puntuación total de FMS <14 puntos, la mayoría de las puntuaciones motoras funcionales eran de 15-16 puntos, de los cuales 19 puntos eran altos y 9 puntos eran bajos. En la intervención basada en la perspectiva de las lesiones deportivas, el valor de medición de la FMS de los ancianos fue mucho mejor que antes, y la evaluación del análisis técnico del movimiento después de la corrección fue significativamente mayor que antes de la corrección. Conclusión: La prevención de las lesiones deportivas propuesta en este artículo puede ayudar eficazmente a las personas mayores a prevenir las lesiones deportivas. Este documento considera el diseño de la prueba FMS como un ejemplo para analizar los movimientos en el entrenamiento deportivo de las personas mayores y para formular normas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

The plyometric activity as a conditioning to enhance strength and precision of the finger movements in pianists.

Stability of timing and force production in repetitive movements characterizes skillful motor behaviors such as surgery and playing musical instruments. However, even trained individuals such as musicians undergo further extensive training for the improvement of these skills. Previous studies that investigated the lower extremity movements such as jumping and sprinting demonstrated enhancement of the maximum force and rate of force development immediately after the plyometric exercises. However, it remains unknown whether the plyometric exercises enhance the stability of timing and force production of the dexterous finger movements in trained individuals. Here we address this issue by examining the effects of plyometric exercise specialized for finger movements on piano performance. We compared the training-related changes in the piano-key motion and several physiological features of the finger muscles (e.g., electromyography, rate of force development, and muscle temperature) by well-trained pianists. The conditioning demonstrated a decrease of the variation in timing and velocity of successive keystrokes, along with a concomitant increase in the rate of force development of the four fingers, but not the thumb, although there was no change in the finger muscular activities through the activity. By contrast, such a conditioning effect was not evident following a conventional repetitive piano practice. In addition, a significant increase in the forearm muscle temperature was observed specifically through performing the plyometric exercise with the fingers, implying its association with improved performance. These results indicate effectiveness of the plyometric exercises for improvement of strength, precision, and physiological efficiency of the finger movements even in expert pianists, which implicates that ways of practicing play a key role in enhancing experts' expertise.

Fuzzy inference system (FIS) - long short-term memory (LSTM) network for electromyography (EMG) signal analysis.

A wide range of application domains,s such as remote robotic control, rehabilitation, and remote surgery, require capturing neuromuscular activities. The reliability of the application is highly dependent on an ability to decode intentions accurately based on captured neuromuscular signals. Physiological signals such as Electromyography (EMG) and Electroencephalography (EEG) generated by neuromuscular activities contain intrinsic patterns for users' particular actions. Such actions can generally be classified as motor states, such as Forward, Reverse, Hand-Grip, and Hand-Release. To classify these motor states truthfully, the signals must be captured and decoded correctly. This paper proposes a novel classification technique using a Fuzzy Inference System (FIS) and a Long Short-Term Memory (LSTM) network to classify the motor states based on EMG signals. Existing EMG signal classification techniques generally rely on features derived from data captured at a specific time instance. This typical approach does not consider the temporal correlation of the signal in the entire window. This paper proposes an LSTM with a Fuzzy Logic method to classify four major hand movements: forward, reverse, raise, and lower. Features associated with the pattern generated throughout the motor state movement were extracted by exploring published data within a given time window. The classification results can achieve a 91.3% accuracy for the 4-way action (Forward/Reverse/GripUp/RelDown) and 95.1% (Forward/Reverse Action) and 96.7% (GripUp/RelDown action) for 2-way actions. The proposed mechanism demonstrates high-level, human-interpretable results that can be employed in rehabilitation or medical-device industries.

Selective effects of a brain tumor on the metric representation of the hand: a pre- versus post-surgery comparison.

Body representation disorders are complex, varied, striking, and very disabling in most cases. Deficits of body representation have been described after lesions to multimodal and sensorimotor cortical areas. A few studies have reported the effects of tumors on the representation of the body, but little is known about the changes after tumor resection. Moreover, the impact of brain lesions on the hand size representation has been investigated in few clinical cases. Hands are of special importance, as no other body part has the ability for movement and interaction with the environment that the hands have, and we use them for a multitude of daily activities. Studies with clinical population can add further knowledge into the way hands are represented. Here, we report a single case study of a patient (AM) who was an expert bodybuilder and underwent a surgery to remove a glioblastoma in the left posterior prefrontal and precentral cortex at the level of the hand's motor region. Pre- (20 days) and post- (4 months) surgery assessment did not show any motor or cognitive impairments. A hand localization task was used, before and after surgery (12 months), to measure possible changes of the metric representation of his right hand. Results showed a post-surgery modulation of the typically distorted hand representation, with an overall accuracy improvement, especially on width dimension. These findings support the direct involvement of sensorimotor areas in the implicit representation of the body size and its relevance on defining specific size representation dimensions.

The effects of robotic assistance on upper limb spatial muscle synergies in healthy people during planar upper-limb training.

BACKGROUND: Robotic rehabilitation is a commonly adopted technique used to restore motor functionality of neurological patients. However, despite promising results were achieved, the effects of human-robot interaction on human motor control and the recovery mechanisms induced with robot assistance can be further investigated even on healthy subjects before translating to clinical practice. In this study, we adopt a standard paradigm for upper-limb rehabilitation (a planar device with assistive control) with linear and challenging curvilinear trajectories to investigate the effect of the assistance in human-robot interaction in healthy people. METHODS: Ten healthy subjects were instructed to perform a large set of radial and curvilinear movements in two interaction modes: 1) free movement (subjects hold the robot handle with no assistance) and 2) assisted movement (with a force tunnel assistance paradigm). Kinematics and EMGs from representative upper-limb muscles were recorded to extract phasic muscle synergies. The free and assisted interaction modes were compared assessing the level of assistance, error, and muscle synergy comparison between the two interaction modes. RESULTS: It was found that in free movement error magnitude is higher than with assistance, proving that task complexity required assistance also on healthy controls. Moreover, curvilinear tasks require more assistance than standard radial paths and error is higher. Interestingly, while assistance improved task performance, we found only a slight modification of phasic synergies when comparing assisted and free movement. CONCLUSIONS: We found that on healthy people, the effect of assistance was significant on task performance, but limited on muscle synergies. The findings of this study can find applications for assessing human-robot interaction and to design training to maximize motor recovery.

Cortical Motor Planning and Biomechanical Stability During Unplanned Jump Landings in Men With Anterior Cruciate Ligament Reconstruction.

CONTEXT: Athletes with anterior cruciate ligament (ACL) reconstruction (ACLR) exhibit increased cortical motor planning during simple sensorimotor tasks compared with healthy athletes serving as control groups. This may interfere with proper decision making during time-constrained movements, elevating the reinjury risk. OBJECTIVE: To compare cortical motor planning and biomechanical stability during jump landings between participants with ACLR and healthy individuals. DESIGN: Cross-sectional study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Ten men with ACLR (age = 28 ± 4 years, time after surgery = 63 ± 35 months) and 17 healthy men (age = 28 ± 4 years) completed 43 ± 4 preplanned (landing leg shown before takeoff) and 51 ± 5 unplanned (visual cue during flight) countermovement jumps with single-legged landings. MAIN OUTCOME MEASURE(S): Movement-related cortical potentials (MRCPs) and frontal θ frequency power before the jump were analyzed using electroencephalography. Movement-related cortical potentials were subdivided into 3 successive 0.5-second time periods (readiness potential [RP]-1, RP-2, and negative slope [NS]) relative to movement onset, with higher values indicating more motor planning. Theta power was calculated for the last 0.5 second before movement onset, with higher values demonstrating more focused attention. Biomechanical landing stability was measured via peak vertical ground reaction force, time to stabilization, and center of pressure. RESULTS: Both the ACLR and healthy groups evoked MRCPs at all 3 time periods. During the unplanned task analyzed using P values and Cohen d, the ACLR group exhibited slightly higher but not different MRCPs, achieving medium effect sizes (RP-1: P = .25, d = 0.44; RP-2: P = .20, d = 0.53; NS: P = .28, d = 0.47). The ACLR group also showed slightly higher θ power values that were not different during the preplanned (P = .18, d = 0.29) or unplanned (P = .42, d = 0.07) condition, achieving small effect sizes. The groups did not differ in their biomechanical outcomes (P values > .05). No condition × group interactions occurred (P values > .05). CONCLUSIONS: Our jump-landing task evoked MRCPs. Although not different between groups, the observed effect sizes provided the first indication that men with ACLR might have consistently relied on more cortical motor planning associated with unplanned jump landings. Confirmatory studies with larger sample sizes are warranted.