Limb Movements Research Articles

GAIT PATTERN INVESTIGATIONS OF BIONIC PIEZOELECTRIC ROBOT

The development of micro-robots based on bionic motion has garnered increasing attention with the advancement of bionic technology. These micro-robots can be employed in various tasks, such as military applications, disaster search and rescue, in vivo drug delivery, minimally invasive surgery, and tumor treatment. Robot joint motion is commonly achieved through actuators, which encompass motor, hydraulic, or pneumatic components that often carry excessive weight. To achieve the goal of miniaturizing robotic mechanisms, innovative actuators need to be developed. This study focuses on designing a four-limbed micro-robot that utilizes piezoelectric actuators. Automatic Dynamic Analysis of the Mechanical System is employed to investigate the kinematic aspects of the micro-robot’s motion, and finite element analysis is also used to obtain the resonant characteristics of the limbs actuated by piezoelectric bimorphs. The results indicate that the gait pattern of a piezoelectric robot changes according to the walking strategy and the robot dimension. The forward travel speed varies depending on the gait pattern, and adjustments in gait design can reduce the up/down oscillation and right/left offset. The robot’s travel speed increases with both trunk and limb length, although longer thigh and leg lengths might lead to greater offset and vertical oscillation. The resonant frequency and mode shapes change with the limb structure and affect the limb motion style. By adjusting the driving frequency of the bimorph actuators, the gait pattern can be manipulated. The information presented in this study contributes to a deeper understanding of micro-robot design.

Sleep Problems in Adults With ADHD: Prevalences and Their Relationship With Psychiatric Comorbidity

Background: Sleep problems are common in adults with ADHD and may be bidirectionally associated with ADHD severity and other psychiatric symptoms. We investigated the prevalence of positive screenings for various sleep disorders, and their association with psychiatric comorbidities in a large sample of adults with ADHD from a specialized outpatient clinic. Methods: We included data of 3,691 adult patients diagnosed with ADHD, who had filled out a screener for sleep disorders (Holland Sleep Disorders Questionnaire (HSDQ)) as part of routine diagnostic assessment. The HSDQ screens for the sleep disorders insomnia, parasomnia, hypersomnia, circadian rhythm sleep disorders (CRSD), restless legs syndrome (RLS)/periodic limb movement disorder (PLMD), and sleep-related breathing disorders (SBD). As delayed sleep phase syndrome (DSPS) is very frequent in ADHD, we additionally screened for DSPS. Psychiatric comorbidities were diagnosed through clinical assessment and the Mini International Neuropsychiatric Interview (M.I.N.I.) Plus, which assesses 26 psychiatric disorders following the classification of the DSM-5. All data were retrieved from the electronic patient files. Results: Mean age was 35.4 and 49.4% of the patients were female. About 60% of the adults with ADHD screened positive for any sleep disorder. Highest prevalences were found for symptoms of DSPS (36%), insomnia (30%), and RLS/PLMD (29%). Sleep problems in adults with ADHD were associated with comorbid depression, anxiety, substance use disorder, personality disorder, and post-traumatic stress disorder. Conclusion: Adults with ADHD often report sleep problems, which are associated with specific psychiatric comorbidities. Systematic screening for sleep disorders in adult patients with ADHD can contribute to a better understanding of their complaints and may aid improved and integrated treatment for the sleep and psychiatric problems.

Exploring core and bridge symptoms in patients recovering from stroke: a network analysis.

Patients recovering from stroke experience a variety of symptoms that present as a synergistic and mutually reinforcing "symptom cluster," rather than as singular symptoms. In this study, we researched and systematic analyzed these symptom clusters, including core and bridge symptoms, to help determine the relationships between symptoms and to identify key symptom targets, providing a new approach for formulating precise symptom management interventions. Convenience sampling was applied to select 432 stroke recovery patients treated in the Seventh People's Hospital of Changzhou City from August 1, 2023 to April 14, 2024. Subsequently, a cross-sectional survey was conducted using the General Information Questionnaire and Stroke Symptom Experience Scale to extract symptom clusters via exploratory factor analysis. Finally, the "qgraph" and "bootnet" packages in the R language were used to construct a network layout to describe the relationships between symptoms and calculate the centrality index. The average age of the 432 enrolled recovering stroke patients was 68.17 ± 12.14 years, including 268 males (62.04%) and 164 females (37.96%), none of whom underwent surgical intervention. Among this cohort, the 3 symptoms with the highest incidence rates were "limb weakness" (A2, 80.56%), "fatigue" (A5, 77.78%), and "limitations of limb movement" (A1, 68.06%). A total of 5 symptom clusters were extracted: the somatic activity disorder, mood-disorder-related, cognitive-linguistic dysfunction, somatic-pain-related, and foot dysfunction symptom clusters. In the symptom network, the 2 most common symptoms in terms of intensity and expected impact were "fatigue" (A5, rs = 1.14, re = 1.00) and "pessimism about the future" (B3, rs = 1.09, re = 1.02). The symptom with the strongest bridge intensity was "limb pain" (D1, rs = 2.64). This study uses symptom network analysis to explore the symptoms of stroke patients during recovery, identifying core symptoms and bridge symptoms. Based on these findings, we can develop more targeted management plans to improve the accuracy and efficiency of interventions. Through this management approach, we can enhance treatment effectiveness, reduce unnecessary medication, lower adverse drug reactions, and optimize the allocation of medical resources.

Posterior Hip Pericapsular Block (PHPB) with pericapsular nerve group (PENG) block for hip fracture: a case series

BackgroundPain after total hip arthroplasty (THA) for femoral neck fracture (FNF) can be severe, potentially leading to serious complications. PENG block has become an optional local analgesic strategy in hip fracture surgery, but it cannot provide effective pain relief for the posterior capsule of the hip joint. Therefore, we modified the traditional sacral plexus nerve block and named it Posterior Hip Pericapsule Block (PHPB) to complement the blockade of the relevant nerves innervating the posterior hip capsule region. Thereby, we detail the analgesic effect of PHPB combined with PENG block on five hip fracture patients and the effect on their hip motor function.MethodsThis case series was conducted from December 2023 to February 2024. We performed ultrasound-guided PHPB combined with PENG block on five patients with hip fractures. Numerical Rating Scale (NRS) pain scores at rest and maximum NRS pain scores during limb movement of the five patients were recorded within 48 h after surgery. Their hip flexion, abduction, adduction, keen flexion and quadriceps muscle strength were also recorded. Serious postoperative complications, including wound infection, hematoma formation, or nerve injury, were recorded.ResultsThey experienced effective pain control within 48 h postoperatively, with NRS pain scores at rest decreasing from 3.0 (3.0, 4.5) to 0.0 (0.0, 1.0) and maximum NRS pain scores during limb movement from 8.0 (7.5, 8.5) to 1.0 (0.5, 2.0). They can autonomously perform hip flexion, abduction, adduction, and knee flexion within 48 h postoperatively without any signs of movement disorders or quadriceps muscle weakness. No severe postoperative complications, such as wound infections, hematoma formation or nerve damage, were observed in any of the patients.ConclusionsUltrasound-guided PENG block combined with PHPB provided effective analgesia for hip fracture patients in the perioperative period. It maintained hip joint motor function and quadriceps muscle strength within 24 h after THA.

Fabrication of TPU-Supported Au-Bi2S3/Ti3C2Tx electrospun mat: Towards flexible and Multi-functional sensors for human motion and NH3 detection at room temperature

The potential applications of wearable sensors in health monitoring, micro-environment detection, and advanced soft electronic noses have attracted widespread attention. However, due to the inherent limitations of traditional organic flexible substrates, simultaneously achieving excellent flexibility, high sensitivity, robustness, and breathability remains a significant challenge. Herein, using the electrospinning method, a flexible TPU substrate film was prepared, and Bi2S3/Ti3C2Tx nanocomposite materials were synthesized through a simple one-step hydrothermal method. Au nanoparticles were attached to the surface of the composite material using sodium borohydride, and finally, the surface impregnation method was used to successfully prepare the Au-Bi2S3/Ti3C2Tx-TPU flexible electrospun mat. The as-prepared sensor demonstrated an outstanding response of 154 % to 100 ppm NH3 at room temperature, coupled with high selectivity, repeatability, and long-term stability. The strain properties of the sensor were also evaluated, showcasing its potential for human motion and physiological feature detection, such as breathing, swallowing, and limb movements. The study’s findings indicated that the Au-Bi2S3/Ti3C2Tx-TPU electrospun mat sensor has promising applications in flexible electronics, wearable environmental monitoring devices, and human healthy monitoring.

State of the Art of Brain Function Detection Technologies in Robot-Assisted Lower Limb Rehabilitation.

Background: With an aging population, the prevalence of neurological disorders is increasing, leading to a rise in lower limb movement disorders and, in turn, a growing need for rehabilitation training. Previous neuroimaging studies have shown a growing scientific interest in the study of brain mechanisms in robot-assisted lower limb rehabilitation (RALLR). Objective: This review aimed to determine differences in neural activity patterns during different RALLR tasks and the impact on neurofunctional plasticity. Methods: Sixty-five articles in the field of RALLR were selected and tested using three brain function detection technologies. Results: Most studies have focused on changes in activity in various regions of the cerebral cortex during different lower limb rehabilitation tasks but have also increasingly focused on functional changes in other cortical and deep subcortical structures. Our analysis also revealed a neglect of certain task types. Conclusion: We identify and discuss future research directions that may contribute to a clear understanding of neural functional plasticity under different RALLR tasks. Impact Statement The evaluation of robot-assisted lower limb rehabilitation based on brain function detection technology can assess the neurological changes of patients in the rehabilitation process by monitoring brain activities and can also provide more accurate guidance for robot-assisted lower limb rehabilitation. By monitoring the patient's brain activity, the robot can adjust according to the real-time status of the patient to achieve more effective rehabilitation training. This has potential impact on improving the rehabilitation effect and speeding up the rehabilitation process of patients.

Statin therapy improves locomotor muscle microvascular reactivity in patients with heart failure with preserved ejection fraction.

Peripheral microvascular dysfunction has been documented in patients with heart failure with preserved ejection fraction (HFpEF), which may be related to elevated levels of inflammation and oxidative stress. Unfortunately, few strategies have been identified to effectively ameliorate this disease-related derangement. Thus, using a parallel, double-blind, placebo-controlled design, this study evaluated the efficacy of 30-day atorvastatin administration (10 mg daily) on lower limb microvascular reactivity, functional capacity, and biomarkers of inflammation and oxidative stress in patients with HFpEF (statin, n = 8, 76 ± 6 yr; placebo, n = 8, 68 ± 9 yr). The passive limb movement (PLM)-induced hyperemic response and 6-min walk test (6MWT) distance were evaluated to assess ambulatory muscle microvascular function and functional capacity, respectively. Circulating biomarkers were also measured to assess the contribution of changes in inflammation and redox balance to these outcomes. The total hyperemic response to PLM, assessed as leg blood flow area under the curve (LBFAUC), increased following the statin intervention (pre, 60 ± 68 mL; post, 164 ± 90 mL; P < 0.01), whereas these variables were unchanged in the placebo group (P = 0.99). There were no significant differences in 6MWT distance following statin or placebo intervention. Malondialdehyde (MDA), a marker of lipid peroxidation, was significantly reduced following the statin intervention (pre, 0.68 ± 0.10; post, 0.51 ± 0.11; P < 0.01) while other circulating biomarkers were unchanged. Together, these data provide new evidence for the efficacy of low-dose statin administration to improve locomotor muscle microvascular reactivity in patients with HFpEF, which may be due, in part, to a diminution in oxidative stress.NEW & NOTEWORTHY This was the first study to investigate the impact of statin administration on locomotor muscle microvascular function in patients with HFpEF. In support of our hypothesis, the total hyperemic response to PLM, assessed as leg blood flow area under the curve, increased, and malondialdehyde, a marker of oxidative damage, was reduced following the statin intervention. Together, these data provide new evidence for the efficacy of statin administration to improve locomotor muscle microvascular reactivity in patients with HFpEF, which may be due, in part, to reduced oxidative stress.

Lower Limb Motion Contributions To The Turnout During A Bipedal Jump In Pre-professional Ballet Dancers

Lower Limb Motion Contributions To The Turnout During A Bipedal Jump In Pre-professional Ballet Dancers

Protocol for upper limb motion analysis in children with cerebral palsy: a proposal for clinical practice

Protocol for upper limb motion analysis in children with cerebral palsy: a proposal for clinical practice

Development of a Gait Analysis Application for Assessing Upper and Lower Limb Movements to Detect Pathological Gait.

Pathological gait in patients with Hakim's disease (HD, synonymous with idiopathic normal-pressure hydrocephalus; iNPH), Parkinson's disease (PD), and cervical myelopathy (CM) has been subjectively evaluated in this study. We quantified the characteristics of upper and lower limb movements in patients with pathological gait. We analyzed 1491 measurements of 1 m diameter circular walking from 122, 12, and 93 patients with HD, PD, and CM, respectively, and 200 healthy volunteers using the Three-Dimensional Pose Tracker for Gait Test. Upper and lower limb movements of 2D coordinates projected onto body axis sections were derived from estimated 3D relative coordinates. The hip and knee joint angle ranges on the sagittal plane were significantly smaller in the following order: healthy > CM > PD > HD, whereas the shoulder and elbow joint angle ranges were significantly smaller, as follows: healthy > CM > HD > PD. The outward shift of the leg on the axial plane was significantly greater, as follows: healthy < CM < PD < HD, whereas the outward shift of the upper limb followed the order of healthy > CM > HD > PD. The strongest correlation between the upper and lower limb movements was identified in the angle ranges of the hip and elbow joints on the sagittal plane. The lower and upper limb movements during circular walking were correlated. Patients with HD and PD exhibited reduced back-and-forth swings of the upper and lower limbs.

Upper limb movement control strategy of top-tier elite male badminton players when smashing for different distances

PurposeMastering the skill of smashing in a game can be quite challenging. Unfortunately, it’s not always easy to control the distance of the smash. The present study investigated the impact of different smashing distances on muscle activation patterns and kinematics of the upper limbs.Material and methodsTen collegiate athletes from a top-ranked team in Korea participated in the present study with a mean age, weight, and height of 21 ± 1 years, 71.9 ± 9.1 kg, and 1.78 ± 2.24 m, respectively. Three valid data points for each subject at three different distances were analyzed using a one-way analysis of variance (ANOVA).ResultsThe results demonstrated that with increasing smashing distance, the internal rotation angle of the elbow and wrist joints decreased, while the angular velocity of flexion and internal rotation of the shoulder, elbow, and wrist joints increased. Muscle activation increased for all muscles except the biceps brachii (BICLO) with increasing distance. The greatest changes in activation levels were observed in the anterior deltoid (DELTA), extensor carpi radialis (ECR), and flexor carpi ulnaris (FCU).ConclusionsDuring tasks with different smashing distances, muscle activation in the upper limbs (except the biceps) increased with increasing distances. Additionally, the internal rotation angle of the upper limbs decreased with increased distances, while the angular velocity of flexion and internal rotation of the shoulder, elbow, and wrist joints increased.

A High‐Precision Dynamic Movement Recognition Algorithm Using Multimodal Biological Signals for Human–Machine Interaction

Accurate recognition of human dynamic movement is essential for seamless human–machine interaction (HMI) across various domains. However, most of the existing methods are single‐modal movement recognition, which has inherent limitations, such as limited feature representation and instability to noise, which will affect its practical performance. To address these limitations, this article proposes a novel fusion approach that can integrate two biological signals, including electromyography (EMG) and bioelectrical impedance (BI). The fusion method combines EMG for capturing dynamic movement features and BI for discerning key postures representing discrete points within dynamic movements. In this method, the identification of key postures and their temporal sequences provide a guiding framework for the selection and weighted correction of probability prediction matrices in EMG‐based dynamic recognition. To verify the effectiveness of the method, six dynamic upper limb movements and nine key postures are defined, and a Universal Robot that can follow movements is employed for experimental validation. Experimental results demonstrate that the recognition accuracy of the dynamic movement reaches 96.2%, representing an improvement of nearly 10% compared with single‐modal signal. This study illustrates the potential of multimodal fusion of EMG and BI in movement recognition, with broad prospects for application in HMI fields.

A Review of Myoelectric Prosthetic Arm Designs from 2011 to 2022

Prosthetic arms are worn by people whose arms have been amputated. Amputation involves surgical removal of the muscle, neurosensory system, and skeletal system. Myoelectric prosthetics make use of the signals generated by the intact muscles for the limb movement. Prosthetic limbs are designed using mechanical parts with suitable gear and motors. Users of prosthetic arms can carry out tasks associated with everyday living and their jobs almost exactly like they would with a natural arm. Prosthetic arms come in a variety of designs based on the needs of the user. The current research reviews the goals, plans, and trials conducted on prosthetic elbows, wrists, and hands between 2011 and 2022 from reputable conferences and journals. In this work, the design of two prosthetic hands with one degree of freedom and thirteen degrees of freedom, respectively, in the 3D simulation tool SolidWorks is described. Prosthetic elbow and a wrist with one degree of freedom were designed as well. The fine motor activities can be performed with the prosthetic fingers designed in this work.

The paradoxical impact of periodic limb movements on isolated REM sleep behavior disorder patients.

Recently, the α-synuclein origin and connectome model described two types of Parkinson's disease: "brain-first" and "body-first" subtypes. We aimed to investigate the role of periodic limb movements during sleep (PLMS) in identifying these subtypes starting from a prodromal stage of α-synucleinopathies. 191 patients with isolated REM sleep behavior disorder (iRBD) underwent video-polysomnography (vPSG), questionnaires, clinical interview, and neuropsychological battery. Patients who presented PLMS index (PLMSi) > 15 were compared with patients presenting PLMSi ≤ 15 on clinical questionnaires, vPSG, and neuropsychological domains with age as a covariate. Correlations were performed between PLMSi and vPSG and neuropsychological domains in both groups of iRBD. 48.2% of patients presented PLMSi > 15. iRBD subgroup with PLMSi > 15 performed better than the iRBD subgroup with PLMSi ≤ 15 in the executive function domain. In patients with PLMSi > 15 negative correlations were observed between PLMSi and some neuropsychological domains (memory, language, and executive function). Moreover, this subgroup was older and their PLMSi was positively correlated with wake-after-sleep onset and inversely correlated with total sleep time and sleep efficiency, suggesting a detrimental effect of PLM on sleep also in this cohort. Patients with PLMSi > 15 are characterized by a more preserved cognitive status, despite a more disrupted sleep. PLMSi could be explored in longitudinal studies concerning the "brain-first" and "body-first" model.

Proposal of Music Therapy Protocol for Ataxic Patients

Neurologic music therapy has been studied as an alternative methodology to stimulate neurological patients in a motor rehabilitation process. It uses music and its elements in a feedback-feedforward system, promoting an environment for neuroplasticity and re-learning of movements. Research to evaluate the use of neurologic music therapy in patients with ataxia due to Parkinson&amp;apos;s and Stroke diseases has shown positive impacts on function rehabilitation, resulting in improvements in activities of daily living and life quality self-perception. The main goals for patients with ataxia described in available research are related to the positive impact on gait function, limb movements, speech, and postural impairment. The most commonly used techniques in neurologic music therapy research are Therapeutical Instrumental Music Performance (TIMP) and Rhythmic Auditory Stimulation (RAS). Literature indicates that both techniques are typically studied independently. Research on the application of neurologic music therapy to ataxic patients, whether due to genetic factors or acquired cerebellar damage, as well as protocols to assist music therapists in implementing these methodologies, are not available. The objective of this study is to propose a music therapy protocol for patients with ataxia from any disease or acquired, using neurologic music therapy and its techniques (TIMP and RAS), to measure the contribution in reducing impacts of ataxia in motor functions, improving patients’ autonomy in daily living activities and as a consequence higher life quality self-perception, also contributing to increasing literature availability regarding this theme. For protocol application feasibility and considering ataxia prevalence in the total population, an experimental group of 15 patients diagnosed with ataxia without impairment on auditory systems will be designed.

Knee joint position sense and kinematic control in relation to motor competency in 13 to 14-year-old adolescents

BackgroundMotor competence (MC) is a key component reflecting one’s ability to execute motor tasks and is an important predictor of physical fitness. For adolescents, understanding the factors affecting MC is pertinent to their development of more sophisticated sporting skills. Previous studies considered the influence of poor proprioceptive ability on MC, however, the relationship between lower limb joint position sense, kinematic control, and MC is not well understood. Therefore, the aim of this study was to determine the relation between joint position sense and kinematic control with MC in adolescents during a lower limb movement reproduction task.MethodsThis study was a cross-sectional design. Young people (n = 427, 196 girls and 231 boys) aged 13 to 14 years were recruited. A movement reproduction task was used to assess joint position sense and kinematic control, while the Movement Assessment Battery for Children (mABC-2) was used to assess MC. In this study, participants were categorized into the Typically Developed (TD, n = 231) and Probable Developmental Coordination Disorder (DCD, n = 80) groups for further analysis of joint position sense, kinematic control, and MC between groups.ResultsKinematic data, specifically normalized jerk, showed a significant correlation with MC. There was no correlation between knee joint position sense and MC, and no group differences between DCD and TD were found.ConclusionsJoint position sense should not be used as a measure to distinguish TD and DCD. Rather than joint position sense, control of kinematic movement has a greater influence on the coordination of the lower limbs in adolescents. Movement control training should be implemented in the clinical setting to target kinematic control, rather than focus on joint position sense practice, to improve motor competency.Trial Registration IdentifierNCT03150784. Registered 12 May 2017, https://clinicaltrials.gov/study/NCT03150784.

Multiphase soft metal enabled high-performance fabric-based wearable energy harvesting

Highly efficient and flexible power sources have always been the focus and goal in the field of wearable electronics. However, the existing wearable power sources are limited by their large size, high weight, electrolyte leakage, and poor mechanical compliance, which seriously hinders their practical applications. Herein, we propose a novel strategy to achieve and demonstrate a fabric-based high-performance wearable triboelectric nanogenerator (TENG) structure. The metals of gallium (Ga), bismuth (Bi), indium (In), and tin (Sn) are mixed according to specific mass ratios, and then they are transformed in liquid phase to form room-temperature multiphase soft metals of GaBiInSn. The material exhibits both metallic and fluidic properties, and possesses a characteristic of multiphase structure. The GaBiInSn material is directly deposited between polytetrafluoroethylene (PTFE) layers and nonwoven fabrics to establish multi-level conductive and frictional interfaces, creating charge transfer and solid-liquid hybrid dielectric layers. Therefore, the thin film-type triboelectric nanogenerators with a structure of PTFE/GaBiInSn/nonwoven fabric (LM-P-TENGs) is manufactured. The LM-P-TENGs can be integrated onto fabrics without compromising their breathability, comfortableness, and flexibility. Particularly, LM-P-TENGs efficiently convert the mechanical energy of human limb movements into sustainable electrical energy output. Under the human limb mechanical triggering conditions, LM-P-TENG achieves a champion specific open-circuit voltage up to 900 V, peak short-circuit current density of 43.3 mA/m2, and high power density of 12.56 W/m2. This work demonstrates the application potential of room-temperature multiphase soft materials in flexible wearable power sources, while introducing a novel power supply mode for wearable electronics. Additionally, the LM-P-TENGs also present applications in self-powered wearables, medical biosensing systems, human-machine interaction systems, near-eye display systems, etc. for the flexible electronics.

A case of alternating hemiplegia in 2-month-old children with nystagmus as the first symptom: A case report.

This case report delves into the rare neurological condition known as alternating hemiplegia of childhood (AHC), focusing on its clinical manifestations, diagnostic approaches, and treatment options. AHC typically presents in infants under the age of 18 months with intermittent episodes of hemiplegia, often triggered by stressors such as environmental changes, bathing, or emotional stress. Recognizing the clinical features of AHC is crucial for early identification and intervention. The paper presents a case of a 2-month-old child with nystagmus as the initial symptom, followed by limb movement disorder in the left upper limb and weakness in the right limbs. The child's condition did not improve with treatment at an external hospital, highlighting the complexity of the disease and the need for specialized care. After a comprehensive review of the patient's medical history, physical examination, and imaging studies, the child was diagnosed with AHC. The diagnosis was confirmed through video electroencephalogram and whole-exome gene detection, which revealed a de novo mutation in the ATP1A3 gene, identified as pathogenic according to the American College of Medical Genetics and Genomics guidelines. The child was admitted to Peking University First Hospital and treated with levetiracetam and flunarizine oral administration. These medications were chosen for their efficacy in managing the symptoms of AHC, particularly the hemiplegic episodes. Post-treatment, the child experienced a reduction in the frequency and intensity of hemiplegic attacks compared to the initial stage. However, the child still exhibited paroxysmal symptoms and abnormal eye movements, and developmental milestones were delayed, indicating the need for ongoing care and monitoring. This case underscores the importance of early recognition and prompt intervention in managing children with AHC. The varied clinical presentations of AHC necessitate vigilance for early differential diagnosis. Although AHC is currently incurable, appropriate treatment can mitigate the impact of complications and improve the long-term quality of life for affected children, facilitating better societal integration.

The use of accelerometers to assess upper limb function in patients with obstetric brachial plexus palsy

For half a century, the Mallet Scale (MS) has been utilized to assess upper limb function in patients with obstetric brachial plexus palsy (OBPP). However, the correct use of the MS requires trained personnel and the MS does not measure compensatory movements. For this reason, new methods are needed to compensate for these weaknesses. This study introduces an innovative method for objective functional motion analysis using accelerometers to measure upper limb movements in thirty patients with obstetric brachial plexus lesions. Five triaxial accelerometers were positioned on the chest and each upper limb. They recorded acceleration signals during repetitive everyday tasks: hand-to-mouth (HM), hand-to-neck (HN), and hand-to-spine (HS). From these signals, 54 features were extracted and subjected to linear correlation tests to identify 5 suitable features. An algorithm was then developed to categorize patients into five groups and compute an individual movement performance score (iMPScore) assessing the patient’s upper extremity function. By using the iMPScore more than 75% of all participants have been classified correctly with respect to their MS category. Identification of MS I category patients in general and assessing upper extremity function of MS I to III in HS tasks were most challenging. We conclude that the introduced approach is a valuable tool for gauging movement limitation of upper limbs in patients with obstetric brachial plexus palsy. Compared to other clinically established methods, it becomes possible to record and even quantify the extent of compensatory movements. In this way, an objective, user- and patient-friendly method is offered, which supports significantly physicians and therapists in their evaluation of OBPP.

Spinal neuron diversity scales exponentially with swim-to-limb transformation during frog metamorphosis.

Vertebrates exhibit a wide range of motor behaviors, ranging from swimming to complex limb-based movements. Here we take advantage of frog metamorphosis, which captures a swim-to-limb-based movement transformation during the development of a single organism, to explore changes in the underlying spinal circuits. We find that the tadpole spinal cord contains small and largely homogeneous populations of motor neurons (MNs) and V1 interneurons (V1s) at early escape swimming stages. These neuronal populations only modestly increase in number and subtype heterogeneity with the emergence of free swimming. In contrast, during frog metamorphosis and the emergence of limb movement, there is a dramatic expansion of MN and V1 interneuron number and transcriptional heterogeneity, culminating in cohorts of neurons that exhibit striking molecular similarity to mammalian motor circuits. CRISPR/Cas9-mediated gene disruption of the limb MN and V1 determinants FoxP1 and Engrailed-1, respectively, results in severe but selective deficits in tail and limb function. Our work thus demonstrates that neural diversity scales exponentially with increasing behavioral complexity and illustrates striking evolutionary conservation in the molecular organization and function of motor circuits across species.