Neuromuscular Control

This study investigated the eect of prolonged intermittent high intensity exercise upon the isokinetic leg strength and electromechanical delay of the knee¯exors. Seven male collegiate soccer players were exposed to: (i) a prolonged intermittent high intensity exercise task (PI-HIET) which required subjects to complete a single-leg pedalling task, with the preferred limb, (75 rpm for all constant-load portions of the task) consisting of 48´1.8 minute cycles of exercise, and (ii) a control task consisting of no exercise. Pre-, mid-and post-PIHIET gravity corrected indices of knee¯exion angle-speci®c torque (0.44 rad knee¯exion (AST); 0 rad full knee extension; [1.05 rad á s A1 ]) were made for both intervention and control limbs. Electromechanical delay (EMD) of the m. biceps femoris during supine knee¯exion movements was evaluated in the preferred leg on both intervention and control days. Repeated measures ANOVAs revealed signi®cant condition (intervention; control) by time (pre; mid; post) interactions for both knee¯exor AST (F [2,12] 4.8; p`0X03) and EMD (F [2,12] 4.1; p`0X05). AST was observed to decrease by 16% and EMD increase by 30% pre to post intervention. These observations suggest an impairment of neuromuscular control and the ability to maintain force generation in the knee¯exors, near the extremes of the range of motion during prolonged intermittent high-intensity exercise activities. Changes of this magnitude may pose a threat to the integrity of the knee joint.

Soccer is the most commonly played sport in the world, with an estimated 265 million active soccer players by 2006. Inherent to this sport is the higher risk of injury to the anterior cruciate ligament (ACL) relative to other sports. ACL injury causes the most time lost from competition in soccer which has influenced a strong research focus to determine the risk factors for injury. This research emphasis has afforded a rapid influx of literature defining potential modifiable and non-modifiable risk factors that increase the risk of injury. The purpose of the current review is to sequence the most recent literature that reports potential mechanisms and risk factors for non-contact ACL injury in soccer players. Most ACL tears in soccer players are non-contact in nature. Common playing situations precluding a non-contact ACL injury include: change of direction or cutting maneuvers combined with deceleration, landing from a jump in or near full extension, and pivoting with knee near full extension and a planted foot. The most common non-contact ACL injury mechanism include a deceleration task with high knee internal extension torque (with or without perturbation) combined with dynamic valgus rotation with the body weight shifted over the injured leg and the plantar surface of the foot fixed flat on the playing surface. Potential extrinsic non-contact ACL injury risk factors include: dry weather and surface, and artificial surface instead of natural grass. Commonly purported intrinsic risk factors include: generalized and specific knee joint laxity, small and narrow intercondylar notch width (ratio of notch width to the diameter and cross sectional area of the ACL), pre-ovulatory phase of menstrual cycle in females not using oral contraceptives, decreased relative (to quadriceps) hamstring strength and recruitment, muscular fatigue by altering neuromuscular control, decreased “core” strength and proprioception, low trunk, hip, and knee flexion angles, and high dorsiflexion of the ankle when performing sport tasks, lateral trunk displacement and hip adduction combined with increased knee abduction moments (dynamic knee valgus), and increased hip internal rotation and tibial external rotation with or without foot pronation. The identified mechanisms and risk factors for non-contact ACL injuries have been mainly studied in female soccer players; thus, further research in male players is warranted. Non-contact ACL injuries in soccer players likely has a multi-factorial etiology. The identification of those athletes at increased risk may be a salient first step before designing and implementing specific pre-season and in-season training programs aimed to modify the identified risk factors and to decrease ACL injury rates. Current evidence indicates that this crucial step to prevent ACL injury is the only option to effectively prevent the sequelae of osteoarthritis associated with this traumatic injury.

Female athletes have a greater susceptibility to knee injury than male athletes. The combination of this greater susceptibility and a 10-fold increase in the female sports population since the inception of Title IX has resulted in a dramatic increase in the number of knee injuries in women. In the United States, women and girls sustain more than 30 000 anterior cruciate ligament (ACL) injuries a year, with costs that may exceed $650 million annually. The mechanism of ACL injury may include a combination of the following components: valgus positioning of the lower extremity; relative extension with unbalanced weight distribution; and the center of the mass of the body displaced away from the plantar surface of the Background: In sports involving pivoting and landing, female athletes suffer knee injury at a greater rate than male athletes.

Study Design: Narrative review. Recent years have brought new research findings on the subject of wrist joint proprioception, which entails an understanding of the wrist as part of a sensorimotor system where afferent information from nerve endings in the wrist joint affects the neuromuscular control of the joint. An understanding of proprioception is also essential to adequately rehabilitate patients after wrist injuries. The aim of this narrative review was to give the reader a background of proprioception as it relates to neuromuscular control and joint stability, what is presently known in relation to the wrist joint and how these findings may be applied to the field of wrist rehabilitation.

This study aimed to estimate normative range for reaction time using ruler drop method for school-going South Asian children between 6 and 12 years of age. A cross-sectional study was used to evaluate the reaction time for 204 children. Normal values for each age group were obtained. The results of multiple linear regressions showed a decrease in the reaction time values with age, and a significant change occurring between six and eight years of age. No difference in reaction time was obtained between boys and girls. Ruler drop method is an easy to use test and the results of this study provide a normative data for age groups 6–12 years ranging from 214.2 ms to 248.8 ms. These values can serve as a reference to screen children with delayed reaction time.

Mastication is a sensory-motor activity aimed at the preparation of food for swallowing. It is a complex process involving activities of the facial, the elevator and suprahyoidal muscles, and the tongue. These activities result in patterns of rhythmic mandibular movements, food manipulation and the crushing of food between the teeth. Saliva facilitates mastication, moistens the food particles, makes a bolus, and assists swallowing. The movement of the jaw, and thus the neuromuscular control of chewing, plays an important role in the comminution of the food. Characteristics of the food, e.g. water and fat percentage and hardness, are known to influence the masticatory process. Food hardness is sensed during mastication and affects masticatory force, jaw muscle activity, and mandibular jaw movements. When we chew for instance a crispy food, the jaw decelerates and accelerates as a result of resistance and breakage of food particles. The characteristic breakage behaviour of food is essential for the sensory sensation. This study presents a short review of the influence of oral physiology characteristics and food characteristics on the masticatory process.

Background: Athletes who return to sport participation after anterior cruciate ligament reconstruction (ACLR) have a higher risk of a second anterior cruciate ligament injury (either reinjury or contralateral injury) compared with non-anterior cruciate ligamentinjured athletes.

This article reviews the results of a series of cadaver investigations aimed at clarifying the role of muscles in the stabilization of ligament-deficient wrists. According to these studies, isometric contraction of some forearm muscles induces midcarpal (MC) supination (ie, the abductor pollicis longus, extensor carpi radialis longus, and flexor carpi ulnaris), whereas other muscles induce MC pronation (ie, the extensor carpi ulnaris). Because MC supination implies tightening of the volar scaphoid-distal row ligaments, the MC supination muscles are likely to prevent scaphoid collapse of wrists with scapholunate ligament insufficiency. MC pronator muscles, by contrast, would be beneficial in stabilizing wrists with ulnar-sided ligament deficiencies owing to their ability to tighten the triquetrum-distal row ligaments. Should these laboratory findings be validated by additional clinical research, proprioceptive reeducation of selected muscles could become an important tool for the treatment of dynamic carpal instabilities.

In the past, the music community conducted research on what makes music more musical or expressive. Much of this work has focused on the manipulation of phras- ing, articulation and rubato to make music more expressive. However, it has been difficult to study neuromuscular control used by experts to create such musical music. This paper took a first step toward

Laboratory demonstrations of brain-computer interface (BCI) systems show promise for reducing disability associated with paralysis by directly linking neural activity to the control of assistive devices. Surveys of potential users have revealed several key BCI performance criteria for clinical translation of such a system. Of these criteria, high accuracy, short response latencies, and multi-functionality are three key characteristics directly impacted by the neural decoding component of the BCI system, the algorithm that translates neural activity into control signals. Building a decoder that simultaneously addresses these three criteria is complicated because optimizing for one criterion may lead to undesirable changes in the other criteria. Unfortunately, there has been little work to date to quantify how decoder design simultaneously affects these performance characteristics. Here, we systematically explore the trade-off between accuracy, response latency, and multi-functionality for discrete movement classification using two different decoding strategies-a support vector machine (SVM) classifier which represents the current state-of-the-art for discrete movement classification in laboratory demonstrations and a proposed deep neural network (DNN) framework. We utilized historical intracortical recordings from a human tetraplegic study participant, who imagined performing several different hand and finger movements. For both decoders, we found that response time increases (i.e., slower reaction) and accuracy decreases as the number of functions increases. However, we also found that both the increase of response times and the decline in accuracy with additional functions is less for the DNN than the SVM. We also show that data preprocessing steps can affect the performance characteristics of the two decoders in drastically different ways. Finally, we evaluated the performance of our tetraplegic participant using the DNN decoder in real-time to control functional electrical stimulation (FES) of his paralyzed forearm. We compared his

Soccer is the most commonly played sport in the world, with an estimated 265 million active soccer players participating in the game as on 2006. Inherent to this sport is the higher risk of injury to the anterior cruciate ligament (ACL) relative to other sports. ACL injury causes a significant loss of time from competition in soccer, which has served as the strong impetus to conduct research that focuses to determine the risk factors for injury, and more importantly, to identify and teach techniques to reduce this injury in the sport. This research emphasis has afforded a rapid influx of literature aimed to report the effects of neuromuscular training on the risk factors and the incidence of non-contact ACL injury in high-risk soccer populations. The purpose of the current review is to sequence the most recent literature relating the effects of prevention programs that were developed to alter risk factors associated with non-contact ACL injuries and to reduce the rate of non-contact ACL injuries in soccer players. To date there is no standardized intervention program established for soccer to prevent non-contact ACL injuries. Multi-component programs show better results than single-component preventive programs to reduce the risk and incidence of non-contact ACL injuries in soccer players. Lower extremity plyometrics, dynamic balance and strength, stretching, body awareness and decision-making, and targeted core and trunk control appear to be successful training components to reduce non-contact ACL injury risk factors (decrease landing forces, decrease varus/valgus moments, and increase effective muscle activation) and prevent non-contact ACL injuries in soccer players, especially in female athletes. Pre-season injury prevention combined with an in-season maintenance program may be advocated to prevent injury. Compliance may in fact be the limiting factor to the overall success of ACL injury interventions targeted to soccer players regardless of gender. Thus, interventional research must also consider techniques to improve compliance especially at the elite levels which will likely influence trickle down effects to sub-elite levels. Future research is also needed for male soccer athletes to help determine the most effective intervention to reduce the non-contact ACL injury risk factors and to prevent non-contact ACL injuries.

Patellofemoral pain (PFP) accounts for 25% of all knee pain presentations in active individuals to outpatient physical therapy clinics.  Historically, the etiology of PFP has been attributed to altered patellofemoral joint mechanics and stresses. However, recent research has suggested insufficient strength of the proximal hip musculature may contribute to PFP.  Many studies exploring the effectiveness of hip strengthening include confounding interventions such as hip strengthening combined with quadriceps strengthening. Therefore, there is a lack of literature exploring the effectiveness of hip strengthening as an isolated intervention in the treatment of PFP. A structured review was conducted to answer the following clinical question: “What is the effect of hip strengthening on pain and function in the rehabilitation of patients under 45 years of age with patellofemoral pain?”
Based on results of 11 studies, there is moderate evidence to suggest that hip strengthening is effective in (1) decreasing general pain and pain during activity and (2) improving generalized lower extremity function during activities such as squatting, walking, and stair negotiation, functional strength and health status in people with PFP. The population that best applies to this review includes active and sedentary men and women 22-35 years old with chronic PFP. Additionally, this review indicates that hip strengthening alone or in combination with quadriceps strengthening or trunk stability training is more effective at improving pain and function compared to quadriceps strengthening alone.

Emergence of proprioceptive training in industrial training facilities seems to reflect current effort of applying therapeutic concept of proprioceptive recovery to general training program. While it is encouraged to continue such efforts, correction of mythical beliefs is necessary ...

A Study To Compare Upper Trunk And Lower Trunk Proprioceptive Neuromuscular Facilitation
Techniques On Improving Postural Control In Hemiplegic Patients. The result showed that lower trunk and
upper trunk PNF technique both were effective to improve postural control in hemiplegic patients. But, lower
trunk PNF technique was more effective than upper trunk PNF technique to improve postural control in
hemiplegic patients.

Background. Knee joint sagittal plane forces are a proposed mechanism of anterior cruciate ligament injury during sport movements such as sidestep cutting. Ligament force magnitudes for these movements however, remain unknown. The need to examine injury-causing events suggests elucidation via model-based investigations is possible. Using this approach, the current study determined whether sagittal plane knee loading during sidestep cutting could in isolation injure the anterior cruciate ligament.

The FIFA 11+ is a structured warm-up programme specially designed to prevent injuries among football players from age 14 years and above. However, studies to prove its efficacy are generally few and it is yet to be tested in male youth footballers and among African players. The purpose of the study was to examine the efficacy of the FIFA 11+ programme in reducing the risk of injuries among male youth football players of the Lagos Junior League. A cluster randomised controlled trial was conducted. All the 20 teams (414 players aged 14 -19 years) in the Premier League division were block-randomised into either an intervention (INT) or a control (CON) group. The INT group performed the FIFA 11+ exercises as warm-up during training sessions and the CON group performed usual warm-up. Participating teams were prospectively followed through an entire league season of 6 months in which they were visited every week to assess injured players for time-loss injuries in both groups. The primary outcomes were any injury to the players, injuries by type of exposure and injuries specific to the lower extremities. The secondary outcomes were injuries reported by body location, aetiology, mechanism and severity. In total, 130 injuries were recorded affecting 104 (25%) of the 416 players. Team and player compliance with the INT was 60% and 74% respectively. Based on the primary outcome measures of the study, the FIFA 11+ programme significantly reduced the overall rate of injury in the INT group by 41% [RR = 0.59 (95% CI: 0.40 -0.86; p = 0.006)] and all lower extremity injuries by 48% [RR = 0.52 (95% CI: 0.34 -0.82; p = 0.004)]. However, the rate of injury reduction based on secondary outcomes mostly did not reach the level of statistical significance. The FIFA 11+ programme is effective in reducing the rates of injuries in male youth football players.

Objective To investigate the effect of a structured warm-up programme designed to reduce the incidence of knee and ankle injuries in young people participating in sports. Design Cluster randomised controlled trial with clubs as the unit of randomisation. Setting 120 team handball clubs from central and eastern Norway (61 clubs in the intervention group, 59 in the control group) followed for one league season (eight months). Participants 1837 players aged 15-17 years; 958 players (808 female and 150 male) in the intervention group; 879 players (778 female and 101 male) in the control group. Intervention A structured warm-up programme to improve running, cutting, and landing technique as well as neuromuscular control, balance, and strength. Main outcome measure The rate of acute injuries to the knee or ankle. Results During the season, 129 acute knee or ankle injuries occurred, 81 injuries in the control group (0.9 (SE 0.09) injuries per 1000 player hours; 0.3 (SE 0.17) in training v 5.3 (SE 0.06) during matches) and 48 injuries in the intervention group (0.5 (SE 0.11) injuries per 1000 player hours; 0.2 (SE 0.18) in training v 2.5 (SE 0.06) during matches). Fewer injured players were in the intervention group than in the control group (46 (4.8%) v (76 (8.6%); relative risk intervention group v control group 0.53, 95% confidence interval 0.35 to 0.81). Conclusion A structured programme of warm-up exercises can prevent knee and ankle injuries in young people playing sports. Preventive training should therefore be introduced as an integral part of youth sports programmes.

Growing numbers of youth participating in competitive, organized phys- ical activity have led to a concern for the risk of sports-related injuries during important periods of human development. Recent studies have demonstrated the ability of integrative neuromuscular training (INT) to enhance athletic performance and reduce the risk of sports-related inju- ries in youth. Successful implementation of INT necessitates instruction from knowledgeable and qualified instructors who understand the unique physical, cognitive, and psychosocial characteristics of the youth to pro- vide appropriate training instruction and feedback. Principles of a clas- sical theory of cognitive development provide a useful context for discussion of developmentally appropriate methods and strategies for INT instruction of youth. INT programs that consider these developmentally appropriate approaches will provide a controlled efficacious environment for youth to improve athletic performance and reduce risk of sports-related injury, thus promoting a healthy active lifestyle beyond an individual’s formative years.

Hamstring injuries are common. The hamstrings and gluteus maximus (GM) work as synergists during hip extension. When contraction of GM is delayed relative to Biceps Femoris (BF) the hamstrings may be predisposed to injury due to increased demand. This study investigated whether specific training affected neuromuscular control of BF and GM during Prone Hip Extension (PHE). Twenty healthy volunteers were randomly allocated to the intervention or the control group. Mean onset times for BF and GM during PHE were recorded via surface electromyography (sEMG). The intervention group performed a 10 min exercise with focus on proximal to distal muscle activation involving abdominal hollowing and active GM contraction prior to PHE. The control group undertook an exercise which included only PHE. Post exercise descriptive analysis indicated that the intervention exercise reduced the delay of GM firing relative to BF, however, when baseline differences between the two groups are taken into account as a covariant, the difference attributable to the intervention is not statistically significant (P ¼ 0.166). The results suggest that a short duration exercise intervention has the potential to alter the timing of activation of GM relative to BF during PHE but this needs validation through future research.

2010): Motor variability in sports: A non-linear analysis of race walking, Journal of Sports Sciences, 28:12, 1327-1336. Journal of Sports Sciences is available online at: http://www.tandfonline.com/doi/abs/for the help provided by his outstand knowledge of race walking technique.

Emergence of proprioceptive training in industrial training facilities seems to reflect current efforts of emphasizing neuromuscular function and postural control in general training programs. While it is encouraged to continue such efforts, correction of mythical beliefs is necessary for more suitable application. Clinicians for the recovery of the sensorimotor function originally suggested the idea of proprioceptive training. Adopting this clinically originated concept to general training created two main misconceptions. One is the premature assumption that proprioception can be improved with physical training. The other is the belief that proprioception is a key factor for the improvement of balance in every occasions. However, there is not sufficient neurophysiological evidence supporting the feasibility of the improvement of the proprioception through physical training. Moreover, proprioception can be effectively used only during the slow or moderately fast closed-loop control of movement. Therefore, overemphasis on proprioception may ignore the role of the central nervous system (CNS) in carrying out motor abilities and skills. A training program should be able to facilitate the CNS adaptation that is a key factor for the development of motor abilities and improvement of skill performance. In order to create an ideal learning environment for the CNS, an exercise program should distinctively train different motor skills with adequately changing task goals and sensory environment. Also, training should help the CNS to overcome its limited attentional capacity by adequately imposing multiple task demands.

Key words: Balance, motor control, proprioception, central nervous system, exercise program, application of therapeutic exercise.

Read more: http://www.readperiodicals.com/201104/2306736741.html#ixzz1ypYBxIA0

The purpose of this study was to identify gender differences in hip motion and kinetics during a single leg bidirectional deceleration maneuver. The rationale for the development of this maneuver was to test dynamic hip control during the deceleration of three different types of singleleg landings. The hypothesis was that female athletes would display increased hip adduction angles and moments during the maneuver compared to male athletes. Thirty-six collegiate soccer players (19 female, 17 male) volunteered to participate. Subjects were instructed to start the maneuver balancing on one foot, to hop through an agility-speed ladder on the same leg ''up two boxes, back one, and then up one and hold it.'' Hip kinematics and kinetics during all three landings were examined. Females demonstrated significantly greater hip adduction angles at initial contact during all three landings and greater maximal hip adduction during landings 1 and 2 compared to male athletes. Females also exhibited significantly increased external hip adduction moments during landing 1, however, no differences were found between genders during landings 2 and 3. ß

Emergence of proprioceptive training in industrial training facilities seems to reflect current efforts of emphasizing neuromuscular function and postural control in general training programs. While it is encouraged to continue such efforts, correction of mythical beliefs is necessary for more suitable application. Clinicians for the recovery of the sensorimotor function originally suggested the idea of proprioceptive training. Adopting this clinically originated concept to general training created two main misconceptions. One is the premature assumption that proprioception can be improved with physical training. The other is the belief that proprioception is a key factor for the improvement of balance in every occasions. However, there is not sufficient neurophysiological evidence supporting the feasibility of the improvement of the proprioception through physical training. Moreover, proprioception can be effectively used only during the slow or moderately fast closed-loop control of movement. Therefore, overemphasis on proprioception may ignore the role of the central nervous system (CNS) in carrying out motor abilities and skills. A training program should be able to facilitate the CNS adaptation that is a key factor for the development of motor abilities and improvement of skill performance. In order to create an ideal learning environment for the CNS, an exercise program should distinctively train different motor skills with adequately changing task goals and sensory environment. Also, training should help the CNS to overcome its limited attentional capacity by adequately imposing multiple task demands.

Brain-computer interface (BCI) neurotechnology has the potential to reduce disability associated with paralysis by translating neural activity into control of assistive devices 1-9. Surveys of potential end-users have identified key BCI system features 10-14 , including high accuracy, minimal daily setup, rapid response times, and multifunctionality. These performance characteristics are primarily influenced by the BCI's neural decoding algorithm 1,15 , which is trained to associate neural activation patterns with intended user actions. Here, we introduce a new deep neural network 16 decoding framework for BCI systems enabling discrete movements that addresses these four key performance characteristics. Using intracorti-cal data from a participant with tetraplegia, we provide offline results demonstrating that our decoder is highly accurate, sustains this performance beyond a year without explicit daily retraining by combining it with an unsupervised updating procedure 3,17-20 , responds faster than competing methods 8 , and can increase functionality with minimal retraining by using a technique known as transfer learning 21. We then show that our participant can use the decoder in real-time to reanimate his paralyzed forearm with functional electrical stimulation (FES), enabling accurate manipulation of three objects from the grasp and release test (GRT) 22. These results demonstrate that deep neural network decoders can advance the clinical translation of BCI technology. The study participant was a 27-year-old male with C5 AIS A tetraplegia due to spinal cord injury. He was implanted with a 96-channel microelectrode array in the hand and arm area of his left primary motor cortex 8,23,24. We trained and evaluated BCI decoders using 80 sessions of intracortical data collected from the participant over 865 d. During each session, the participant performed two 104-s blocks of the four-movement task (Methods), in which he was cued to imagine a series of four distinct hand movements (index extension, index flexion, wrist extension, wrist flexion) in a random order (Fig. 1a,b). We calibrated the initial neural network (NN) model using 40 sessions (80 blocks) from the training period (Fig. 1c). As the model was not updated at all over the subsequent test period, we call it the fixed NN (fNN). Two additional NN models were created from the fNN using updating procedures that used the first block of each of the 40 sessions in the testing period in different ways (Fig. 1c): supervised updating (sNN) or unsupervised updating (uNN) (Fig. 1d and Methods). In this context, supervised refers to the algorithm using explicit training labels (i.e., known timing and type of intended action) as opposed to unsupervised, in which the timing and type of intended action were unknown, as occurs with general BCI use. For comparison, the first block of each of the 40 sessions in the testing period was also used to calibrate benchmark BCI decoders that were retrained daily: a support vector machine (SVM) decoder (Fig. 1d) 8,23,25,26 , a linear discriminant analysis (LDA) decoder 17 , and a naive Bayes decoder 18. The SVM performed better than the LDA or naive Bayes decoder (Supplementary Fig. 1) and was thus used for further comparisons with NN performance. Neural features used by all models were the mean wavelet power (MWP) values calculated from raw voltage for each of the 96 channels over 100-ms bins 8,23,24 (Fig. 1e, Supplementary Fig. 2, and Methods). Performance for each of the NN and comparison models was initially evaluated using accuracy (percentage of correctly predicted time-bins) on the second block of data from each session during the testing period (Methods). Figure 1e shows data processing steps and NN model architecture. To quantify improved BCI accuracy with the NN, we compared the performance of the supervised, daily-updated sNN against a daily-retrained SVM. Figure 2a,b shows that the sNN was more accurate than the daily-retrained SVM for all sessions, with a mean difference of 6.35 ± 2.47% (mean ± s.d.; P = 3.69 × 20-8 , V = 820, n = 40 paired two-sided Wilcoxon signed rank test; n is the sample size and V is the test statistic for the paired Wilcoxon test). In addition, for 37 out of 40 sessions, the sNN accuracy was > 90%, indicating consistently high performance in accordance with user expectations 13. In contrast, the SVM accuracy was > 90% for only 12 sessions. To demonstrate that a BCI with a neural network decoder (NN-BCI) could sustain high accuracy for over a year without the need of supervised updating (thus reducing daily setup time), we evaluated performance of the fNN. Figure 2c shows that the fNN was more accurate than the daily-retrained SVM for 36 out of 40 test sessions, with a mean difference of 4.56. ± 3.06% (P = 1.90 × 10-7 , V = 798, n = 40; Fig. 2c, inset). In addition, the fNN accuracy was > 90% for 32 sessions. Not only was the fNN able to sustain high accuracy decoding performance for over a year (381 d) without being recalibrated, it significantly outperformed all fixed versions of the benchmark decoders we tested (Supplementary Fig. 1). However, the fNN accuracy was lower than that of the sNN (Fig. 2d), which received supervised updates throughout the testing period. In fact,

This chronic disease, Myasthenia Gravis (MG) is a disease that has no cure, according to some experts.

Myasthenia gravis ( MG) is a neuromuscular disease that leads to fluctuating muscle weakness and fatigue. In the most common cases, muscle weakness is caused by circulating antibodies that block nicotinic acetylcholine receptors at the postsynaptic neuromuscular junction.

However, there are several ways to control and can help in dealing with this chronic disease of Muscle Weakness Disorder.

Learn what is the Relationship between the thymus gland and myasthenia gravis.

Individuals with tetraplegia identify restoration of hand function as a critical, unmet need to regain their independence and improve quality of life. Brain-Computer Interface (BCI)-controlled Functional Electrical Stimulation (FES) technology addresses this need by reconnecting the brain with paralyzed limbs to restore function. In this study, we quantified performance of an intuitive, cortically-controlled, transcutaneous FES system on standardized object manipulation tasks from the Grasp and Release Test (GRT). We found that a tetraplegic individual could use the system to control up to seven functional hand movements, each with >95% individual accuracy. He was able to select one movement from the possible seven movements available to him and use it to appropriately manipulate all GRT objects in real-time using naturalistic grasps. With the use of the system, the participant not only improved his GRT performance over his baseline, demonstrating an increase in number of transfers for all objects except the Block, but also significantly improved transfer times for the heaviest objects (videocassette (VHS), Can). Analysis of underlying motor cortex neural representations associated with the hand grasp states revealed an overlap or non-separability in neural activation patterns for similarly shaped objects that affected BCI-FES performance. These results suggest that motor cortex neural representations for functional grips are likely more related to hand shape and force required to hold objects, rather than to the objects themselves. These results, demonstrating multiple, naturalistic functional hand movements with the BCI-FES, constitute a further step toward translating BCI-FES technologies from research devices to clinical neuroprosthetics.

Summary The body of the vertebra can be affected in the majority of the conditions involving the lumbar spine. Multiple references, both books and periodicals, have been reviewed, and the anatomical factors responsible for the vertebral body integrity in the lumbar spine have been included under the following important areas, namely, morphology, development, genetics, microscopic examination using histology, structural architecture, blood supply, neuromuscular control, and biomechanics. Introduction The anatomy provides a three-dimensional frame work to support the interaction between the physiological and pathological alterations. The body of the vertebra can be affected in a majority of acute or chronic conditions involving the lumbar spine. The etiology of these conditions is multifactorial, which has been dealt with in previous studies sporadically. This study aims to review and incorporate the important anatomical factors which can influence the integrity of vertebral bodies in the lumbar region and manifest as low back pain. Methods Multiple references, both books and periodicals, have been reviewed for the literature. Electronic databases, including Medline and PubMed, were used to collect the latest information. They were finally arranged in an anatomical framework for the article. An attempt has been made to cover these relevant issues in an integrated way in the article and have been structured into introduction, morphology, development, genetics, microscopic examination using histology, structural architecture, blood supply, neuromuscular control, biomechanics, and conclusion. The aforementioned anatomical aspects, some of which have received less attention in the literature, may be helpful to clinicians for restoring the mobility, stability, and load bearing capacity of the lumbar spine as well as planning better management strategies, especially for the chronic low back pain. Results In our article all the anatomical factors affecting the integrity of vertebral body, including the morphology, development, genetics, growth and ossification, blood supply, specifically in the lumbar region, have been described, which were not covered earlier. The limitations of this review is its wide dimensions; hence, there are fair scopes of missing many relevant facts, as all of them cannot be compiled in a single article. We have attempted to confine our views to different anatomical domains only, this is our second limitation. Additional studies are required to incorporate and discuss the uncovered relevant scientific details. Conclusions The integrity of the body of the lumbar vertebra is multifactorial (Fig. 8). The vast spectrum of the anatomical domain influencing it has been summarized. The evolution of erect posture is a landmark in the morphology of human beings and the lumbar lordosis, which has also contributed to the gross design of the vertebral body, is one of the most important adaptations for axial loading and bipedal movements. The role of metamerism in the evolution of vertebrate morphology is repeated in the development of spine. The body of the vertebra is intersegmental in origin, which results in dual vascular and nerve supply, both from superior and inferior aspects of the body of the lumbar vertebrae. The vertebral body ossifies from three primary centers, one for centrum, which will form the major portion of body, and the other two for neural arches. The cartilaginous growth plate is mainly responsible for the longitudinal vertebral growth. Regional differentiation of the vertebral column, and the definite pattern of the structure of the different vertebra, is regulated by a large number of genetic factors, including the Hox genes. The vertebral body design therefore provides the requirements for optimal load transfer by maximal strength with minimal weight. Bone mineral density (BMD), bone quality, microarchitecture, and material properties are the important factors that contribute to bone strength. BMD is highly heritable; bone mineral distribution and architecture are also shown to be under strong genetic influence. All the aforementioned factors finally integrate to ensure mainly the mobility, stability, and load bearing capacity of the lumbar spine.

Lifting-induced fatigue may influence neuromuscular control of spinal stability. Stability is primarily controlled by muscle recruitment, active muscle stiffness, and reflex response. Fatigue has been observed to affect each of these neuromuscular parameters and may therefore affect spinal stability. A biomechanical model of spinal stability was implemented to evaluate the effects of fatigue on spinal stability. The model included a 6-degree-of-freedom representation of the spine controlled by 12 deformable muscles from ...

The present study utilized high-impact supra-maximal landings to examine the influence of the pre-impact force level on the post-impact electromyographic (EMG) activity and, in particular, on the short latency EMG reflex (SLR) component. Unilateral-leg landings were performed in a sitting position on a sledge apparatus after release from high, but individually constant dropping height. A lower limb guiding device fixed to the front of the sledge seat allowed the subjects to sustain a given pre-set force level up to impact. This force level was either freely chosen or set at 20, 35, and 50% of maximal isometric plantarflexion force. EMG activity was recorded from eight major lower limb muscles. It was expected that the increase in the pre-impact force level would require the intervention of a protective neural strategy during the post-impact phase that would attenuate the SLR amplitude. The ultrasonography recordings confirmed that the soleus fascicles were stretched to induce SLR. T...

Background Sprint events in crosscountry skiing are unique not only with respect to their length (0.8-1.8 km), but also in involving four high-intensity heats of *3 min in duration, separated by a relatively short recovery period (15-60 min). Objective Our aim was to systematically review the scientific literature to identify factors related to the performance of elite sprint crosscountry skiers. Methods Four electronic databases were searched using relevant medical subject headings and keywords, as were reference lists, relevant journals, and key authors in the field. Only original research articles addressing physiology, biomechanics, anthropometry, or neuromuscular characteristics and elite sprint crosscountry skiers and performance outcomes were included. All articles meeting inclusion criteria were quality assessed. Data were extracted from each article using a standardized form and subsequently summarized. Results Thirty-one articles met the criteria for inclusion, were reviewed, and scored an average of 66 ± 7 % (range 56-78 %) upon quality assessment. All articles except for

Objective: Paralysis resulting from spinal cord injury (SCI) can have a devastating effect on multiple arm and hand motor functions. Rotary hand movements, such as supination and pronation, are commonly impaired by upper extremity paralysis, and are essential for many activities of daily living. In this proof-of-concept study, we utilize a neural bypass system (NBS) to decode motor intention from motor cortex to control combinatorial rotary hand movements elicited through stimulation of the arm muscles, effectively bypassing the SCI of the study participant. We describe the NBS system architecture and design that enabled this functionality. Methods: The NBS consists of three main functional components: 1) implanted intracortical microelectrode array, 2) neural data processing using a computer, and, 3) a non-invasive neuromuscular electrical stimulation (NMES) system. Results: We address previous limitations of the NBS, and confirm the enhanced capability of the NBS to enable, in real-time, combinatorial hand rotary motor functions during a functionally relevant object manipulation task. Conclusion: This enhanced capability was enabled by accurate decoding of multiple movement intentions from the participant's motor cortex, interleaving NMES patterns to combine hand movements, and dynamically switching between NMES patterns to adjust for hand position changes during movement. Significance: These results have implications for enabling complex rotary hand functions in sequence with other

In chronic low back pain patients (CLBP), neuromuscular and pain intensity have been identified as contributing factors in the disability of the individual. However, it is unclear whether pain intensity influences neuromuscular activation and if directed attention mediates this relationship. Thus, the purpose of this study was to determine the effect of directed attention in individuals with different pain intensities on back extensor activation profiles. Fifty-four CLBP patients were separated into either high-or low-pain groups. Surface electromyograms were recorded from back muscles while the subjects performed a trunk flexion motion for four different attention conditions. Pattern recognition and repeated measures ANOVAs were used to examine the effect of sex, attention and pain intensity on temporal muscle activation patterns. The results showed that there was a significant sex 9 attention 9 pain interaction. The largest changes in muscle timing were observed in the low-pain group when their attention was focused on their pain, but the pattern of muscle activation differed between sexes. For males, a rapid decline in activation at mid-extension occurred, whereas females showed delayed activation at the beginning of extension. Overall, this study demonstrated that directed attention on pain had an effect on trunk muscle temporal recruitment, and that this relationship differed between sexes and pain groups. This suggests that sex-specific mechanisms may alter the neuromuscular control of the spine in CLBP patients for different pain levels.

Coral snakes, most notably the genus Micrurus, are the only terrestrial elapid snakes in the Americas. Elapid venoms are generally known for their potent neurotoxicity which is usually caused by Three-Finger Toxin (3FTx) proteins. These toxins can have a wide array of functions that have been characterized from the venom of other elapids. We examined publicly available sequences from Micrurus 3FTx to show that they belong to 8 monophyletic clades that diverged as deep in the 3FTx phylogenetic tree as the other clades with characterized functions. Functional residues from previously characterized clades of 3FTx are not well conserved in most of the Micrurus toxin clades. We also analyzed the patterns of selection on these toxins and find that they have been diversifying at different rates, with some having undergone extreme diversifying selection. This suggests that Micrurus 3FTx may contain a previously underappreciated functional diversity that has implications for the clinical outcomes of bite victims, the evolution and ecology of the genus, as well as the potential for biodiscovery efforts focusing on these toxins. Keywords Coral snake · Elapid · Micrurus · Venom · Three-finger toxin · 3FTx