Amplitude Of Motion Research Articles

Development of static balance in professional-applied physical training of cadets with specific learning conditions.

Annotation. Successful professional activity of specialists of the National Police of Ukraine is ensured through the formation of a wide range of professional competencies, which, in particular, provides for the comprehensive development of professionally significant physical qualities during the training of cadets in higher education institutions with specific learning conditions. Taking into account the growing complexity and variety of tasks facing modern police officers, the list of priority physical qualities that a graduate of a higher education institution should have is expanding. The analysis of the content of educational programs in the practical disciplines of higher education institutions shows that they are mainly focused on the development of cadets: strength, flexibility, speed qualities, strength and speed endurance. In the educational process, not enough attention is paid to the development of coordination abilities, which ensure the rational distribution of muscular efforts during physical exercises, the optimal amplitude of movements, the efficiency of motor actions and the economy of energy consumption, and prevent injuries. The authors focus on the fact that modern control tests and standards for assessing physical fitness, used in the system of the Ministry of Internal Affairs of Ukraine, do not make it possible to fully assess the level of development of priority motor qualities of future police officers. It is proposed to use in the educational process of higher education the test for assessing static equilibrium according to the method of E. Y. Bondarevskiy. To develop coordination abilities, it is recommended to use the following exercises: from somat yoga; swimming; Nordic walking; maintaining balance on an unstable platform, with the performance of acyclic motor actions; on a reduced support area; on one leg.

Initial treatment experience obtained with the real-time predictive motion tracking radiotherapy platform Synchrony: A pilot study.

This pilot study presents initial experience obtained with a real-time predictive motion tracking platform called Synchrony mounted on the Radixact radiotherapy device. Synchrony radiotherapy treatments were offered as an alternative to surgical excision for primary pulmonary carcinomas as well as in dogs in a suspected oligometastatic disease state. All dogs were treated with three fractions of 8 Gy. Six dogs with pulmonary targets were successfully treated, while we were unable to treat abdominal targets with implanted fiducials. Cranial targets showed minimal movement, while targets located adjacent to the diaphragm showed a large amplitude of movement. No acute or late clinically apparent side effects were noted in any of the dogs that received radiation therapy. A strong partial response with minimal pneumonitis was seen in follow-up imaging of the one dog where imaging was available. Synchrony motion tracking will continue to be investigated for efficacy.

Hip joint motion amplitude control based on exponential product formula

Background: Handball is a team sport, and during a game, there is a lot of direct squabbling and close contact between the players. Objective: The goal of the research is to determine how handball training affected several aspects of physical fitness. The study also investigates the relationship between playing handball, passive hip range of motion (ROM), and the development of radiologically detectable hip osteoarthritis (OA) in formerly elite handball players. The research employed the exponential product algorithm for evaluating bilateral radiographs to classify and diagnose hip OA. This technique most likely evaluated subchondral sclerosis, osteophyte formation, joint space narrowing, and other radiological signs of OA in the individuals’ hip joints. Methods: The relationship among the risk of hip OA in long-term top handball players is explored, as well as the connections among hip ROM, OA, and pain. The research was conducted using a sample size of 20 ex-professional handball players and 39 control subjects. Information on demographics, loading patterns during exercise, and history of lower limb joint injury were gathered via a questionnaire. The inclusion criteria for individuals consisted former professional handball players with significant elite-level competitive experience, as well as control subjects with no background of high-impact sports. Confounding characteristics such as age, gender, and previous lower limb joint injuries were carefully controlled for using extensive demographic and injury history evaluations. To identify and categorize hip OA, bilateral radiographs were analyzed using the exponential product algorithm. The goniometer was used to assess the bilateral passive hip ROM. Long-term participation in elite handball at a high level was found to have a strong correlation with the hip development of osteoarthritis (OA). Sixty percent of handball players had been identified with OA in at least one hip joint, compared to only thirteen percent of control patients. Results: Hip flexion and medial rotation in the handball players were significantly decreased, whereas abduction, extension, and lateral rotation were increased considerably compared to the control values. When doing daily activities, the hip joints of the handball players with OA were less painful than those of the OA-afflicted control participants. Retired handball players seem to be at a much higher risk than the general population for developing early hip OA. Conclusion: The repetitive nature of handball-specific movements may result in anomalies that are seldom seen in the general population, which makes diagnosing pain and discomfort a challenging diagnostic challenge for sports physicians.

Unsteady CFD simulation of a rotor blade under various wind conditions

Wind and gusts can significantly impact the performance of rotors and turbines. The transient behavior of the rotor should be carefully examined to account for these effects. This paper investigates the unsteady aerodynamic characteristics of a rotor blade under different wind conditions, such as direction, speed, and angle. A 3D transient Computational Fluid Dynamics (CFD) simulation using the dynamic mesh technique is performed to analyze the rotor dynamics. The unsteady Reynolds-averaged Navier–Stokes (URANS) equations with the k-ω SST turbulence model are solved. The rotor blade used for this study is the U15XXL Combo KV29 industrial blade, which has not been numerically analyzed before. The results show that wind in the same direction as the rotation reduces the thrust more than lateral or opposite wind. Lateral wind with a speed lower than 5 m/s decreases the blade performance, but higher speeds increase it. Higher lateral wind speeds also cause two peaks in the torque curve, forming a butterfly wing shape in the polar torque plot and multiple extrema in the torque curve with increasing speed. The maximum thrust shifts slightly to the left with increasing lateral wind speed. The lateral angle does not affect the average thrust produced in one blade revolution but only causes a spatial shift. The thrust production decreases as the angle approaches the opposite direction of rotation. The motion amplitude decreases, and the curve becomes smoother as this angle increases. A nearly straight line similar to no side wind is observed at 60 and 90 degrees, which is attributed to the constant effective angle of attack during the rotation cycle.

MIDDLE PLEISTOCENE NEOTECTONIC ACTIVATION OF THE MOUNTAIN BORDERING THE MUYA-KUANDA RIFT VALLEY (BAIKAL RIFT ZONE)

Geological and geomorphological studies of the northeastern branch of the Baikal rift zone have revealed structural features of sedimentary strata, as well as the features of lithology and interaction of heterochronous loose sedimentary complexes, block structure of rift valley bottoms and their mountain border, fault network, and activated Cenozoic faults. The Middle Pleistocene neotectonic uplift was identified on the southern slopes of the North Muya and the Kodar ranges and in the mountains bordering the Muya-Kuanda and Parama rift valleys. The authors have studied the parameters of this uplift, determined neotectonic movement amplitudes in the uplift areas, traced the marginal disjunctives and the kinematics of their movements, and identified homochromous sedimentary strata and determined their formation age.The activation of tectonic processes, during which the neotectonic uplift was formed, occurred in the early Middle Pleistocene, before the onset of glaciation. The formation of a dammed lake in the system of Muya-Kuanda rift valleys is associated with the tectonic damming of the Vitim River. During the Middle Pleistocene glaciation, the Kodar Range glaciers have twice formed the ice dams in the area of Lake Oron, which led to the emergence of dammed lakes in the Vitim valley connected with lakes in the Muya-Kuanda troughs. The shoreline of these lakes is preserved as a high rock terrace with an absolute height of 860±10 m along the perimeter of the rift valleys.In the Late Pleistocene, the terrace complex in the Muya-Kuanda rift valleys was mainly formed under the influence of climatic factor.

Deep learning-aided respiratory motion compensation in PET/CT: addressing motion induced resolution loss, attenuation correction artifacts and PET-CT misalignment.

Respiratory motion (RM) significantly impacts image quality in thoracoabdominal PET/CT imaging. This study introduces a unified data-driven respiratory motion correction (uRMC) method, utilizing deep learning neural networks, to solve all the major issues caused by RM, i.e., PET resolution loss, attenuation correction artifacts, and PET-CT misalignment. In a retrospective study, 737 patients underwent [18F]FDG PET/CT scans using the uMI Panorama PET/CT scanner. Ninety-nine patients, who also had respiration monitoring device (VSM), formed the validation set. The remaining data of the 638 patients were used to train neural networks used in the uRMC. The uRMC primarily consists of three key components: (1) data-driven respiratory signal extraction, (2) attenuation map generation, and (3) PET-CT alignment. SUV metrics were calculated within 906 lesions for three approaches, i.e., data-driven uRMC (proposed), VSM-based uRMC, and OSEM without motion correction (NMC). RM magnitude of major organs were estimated. uRMC enhanced diagnostic capabilities by revealing previously undetected lesions, sharpening lesion contours, increasing SUV values, and improving PET-CT alignment. Compared to NMC, uRMC showed increases of 10% and 17% in SUVmax and SUVmean across 906 lesions. Sub-group analysis showed significant SUV increases in small and medium-sized lesions with uRMC. Minor differences were found between VSM-based and data-driven uRMC methods, with the SUVmax was found statistically marginal significant or insignificant between the two methods. The study observed varied motion amplitudes in major organs, typically ranging from 10 to 20mm. A data-driven solution for respiratory motion in PET/CT has been developed, validated and evaluated. To the best of our knowledge, this is the first unified solution that compensates for the motion blur within PET, the attenuation mismatch artifacts caused by PET-CT misalignment, and the misalignment between PET and CT.

On-board synthetic 4D MRI generation from 4D CBCT for radiotherapy of abdominal tumors: A feasibility study.

Magnetic resonance-guided radiotherapy with an MR-guided LINAC represents potential clinical benefits in abdominal treatments due to the superior soft-tissue contrast compared to kV-based images in conventional treatment units. However, due to the high cost associated with this technology, only a few centers have access to it. As an alternative, synthetic 4D MRI generation based on artificial intelligence methods could be implemented. Nevertheless, appropriate MRI texture generation from CT images might be challenging and prone to hallucinations, compromising motion accuracy. To evaluate the feasibility of on-board synthetic motion-resolved 4D MRI generation from prior 4D MRI, on-board 4D cone beam CT (CBCT) images, motion modeling information, and deep learning models using the digital anthropomorphic phantom XCAT. The synthetic 4D MRI corresponds to phases from on-board 4D CBCT. Each synthetic MRI volume in the 4D MRI was generated by warping a reference 3D MRI (MRIref, end of expiration phase from a prior 4D MRI) with a deformation field map (DFM) determined by (I) the eigenvectors from the principal component analysis (PCA) motion-modeling of the prior 4D MRI, and (II) the corresponding eigenvalues predicted by a convolutional neural network (CNN) model using the on-board 4D CBCT images as input. The CNN was trained with 1000 deformations of one reference CT (CTref, same conditions as MRIref) generated by applying 1000 DFMs computed by randomly sampling the original eigenvalues from the prior 4D MRI PCA model. The evaluation metrics for the CNN model were root-mean-square error (RMSE) and mean absolute error (MAE). Finally, different on-board 4D-MRI generation scenarios were assessed by changing the respiratory period, the amplitude of the diaphragm, and the chest wall motion of the 4D CBCT using normalized root-mean-square error (nRMSE) and structural similarity index measure (SSIM) for image-based evaluation, and volume dice coefficient (VDC), volume percent difference (VPD), and center-of-mass shift (COMS) for contour-based evaluation of liver and target volumes. The RMSE and MAE values of the CNN model reported 0.012±0.001 and 0.010±0.001, respectively for the first eigenvalue predictions. SSIM and nRMSE were 0.96±0.06 and 0.22±0.08, respectively. VDC, VPD, and COMS were 0.92±0.06, 3.08±3.73 %, and 2.3±2.1mm, respectively, for the target volume. The more challenging synthetic 4D-MRI generation scenario was for one 4D-CBCT with increased chest wall motion amplitude, reporting SSIM and nRMSE of 0.82 and 0.51, respectively. On-board synthetic 4D-MRI generation based on predicting actual treatment deformation from on-board 4D-CBCT represents a method that can potentially improve the treatment-setup localization in abdominal radiotherapy treatments with a conventional kV-based LINAC.

Jaw-neck motor function 2 years after whiplash trauma.

There is limited knowledge about the possible long-term effects on jaw motor function after whiplash trauma. The primary aim was to evaluate integrated jaw and head-neck movement amplitudes during jaw function in individuals 2 years after whiplash trauma, compared to controls. The secondary aim was to evaluate changes between the acute stage and a 2-year follow-up in terms of jaw and head-neck movement amplitudes during jaw function. This study included 28 cases exposed to a whiplash trauma 2 years earlier (13 women) and 28 controls (13 women) without previous neck trauma. Head and jaw movement amplitudes were recorded during maximal jaw opening-closing movements using an optoelectronic 3D recording system. For a subpopulation of 12 cases and 15 controls, recordings had also been performed in the acute stage after the whiplash trauma. Jaw and head movement amplitudes were analysed using linear regression with group and sex as independent variables. The subpopulation longitudinal analysis was adjusted for movement amplitudes at baseline. Jaw movement amplitudes were significantly associated with group (coefficient: -0.359: 95% CI: -10.70 to -1.93, p = .006) with smaller amplitudes of jaw movements for whiplash cases. Head movement amplitudes were not associated with group (coefficient: -0.051, 95% CI: -4.81 to 3.20, p = .687). In the longitudinal analysis, both jaw and head movement amplitudes showed significant associations between baseline and the 2-year follow-up. The present findings indicate that the effects on jaw function in terms of jaw opening capacity in the acute stage after whiplash trauma do not spontaneously recover.

Lateralization of acquisition and consolidation in direction but not amplitude of a motor skill task.

Previous research suggests that the neural processes underlying specification of movement direction and amplitude are independently represented in the nervous system. However, our understanding of acquisition and consolidation processes in the direction and distance learning remains limited. We designed a virtual air hockey task, in which the puck direction is determined by the hand direction at impact, while the puck distance is determined by the amplitude of the velocity. In two versions of this task, participants were required to either specify the direction or the distance of the puck, while the alternate variable did not contribute to task success. Separate groups of right-handed participants were recruited for each task. Each participant was randomly assigned to one of two groups with a counter-balanced arm practice sequence (right to left, or left to right). We examined acquisition and, after 24h, we examined two aspects of consolidation: 1) same hand performance to test the durability and 2)the opposite hand to test the effector-independent consolidation (interlimb transfer) of learning. The distance task showed symmetry between hands in the extent of acquisition as well as in both aspects of consolidation. In contrast, the direction task showed asymmetry in both acquisition and consolidation: the dominant right arm showed faster and greater acquisition and greater transfer from the opposite arm training. The asymmetric acquisition and consolidation processes shown in the direction task might be explained by lateralized control and mapping of direction, an interpretation consistent with previous findings on motor adaptation paradigms.

Spatiotemporal correlation enhanced real-time 4D-CBCT imaging using convolutional LSTM networks.

To enhance the accuracy of real-time four-dimensional cone beam CT (4D-CBCT) imaging by incorporating spatiotemporal correlation from the sequential projection image into the single projection-based 4D-CBCT estimation process. We first derived 4D deformation vector fields (DVFs) from patient 4D-CT. Principal component analysis (PCA) was then employed to extract distinctive feature labels for each DVF, focusing on the first three PCA coefficients. To simulate a wide range of respiratory motion, we expanded the motion amplitude and used random sampling to generate approximately 900 sets of PCA labels. These labels were used to produce 900 simulated 4D-DVFs, which in turn deformed the 0% phase 4D-CT to obtain 900 CBCT volumes with continuous motion amplitudes. Following this, the forward projection was performed at one angle to get all of the digital reconstructed radiographs (DRRs). These DRRs and the PCA labels were used as the training data set. To capture the spatiotemporal correlation in the projections, we propose to use the convolutional LSTM (ConvLSTM) network for PCA coefficient estimation. For network testing, when several online CBCT projections (with different motion amplitudes that cover the full respiration range) are acquired and sent into the network, the corresponding 4D-PCA coefficients will be obtained and finally lead to a full online 4D-CBCT prediction. A phantom experiment is first performed with the XCAT phantom; then, a pilot clinical evaluation is further conducted. Results on the XCAT phantom and the patient data show that the proposed approach outperformed other networks in terms of visual inspection and quantitative metrics. For the XCAT phantom experiment, ConvLSTM achieves the highest quantification accuracy with MAPE(Mean Absolute Percentage Error), PSNR (Peak Signal-to-Noise Ratio), and RMSE(Root Mean Squared Error) of 0.0459, 64.6742, and 0.0011, respectively. For the patient pilot clinical experiment, ConvLSTM also achieves the best quantification accuracy with that of 0.0934, 63.7294, and 0.0019, respectively. The quantification evaluation labels that we used are 1) the Mean Absolute Error (MAE), 2) the Normalized Cross Correlation (NCC), 3)the Structural Similarity Index Measurement(SSIM), 4)the Peak Signal-to-Noise Ratio (PSNR), 5)the Root Mean Squared Error(RMSE), and 6) the Absolute Percentage Error (MAPE). The spatiotemporal correlation-based respiration motion modeling supplied a potential solution for accurate real-time 4D-CBCT reconstruction.

Effects of Topology Optimization in Multimaterial 3D Bioprinting of Soft Actuators

Recently, there has been a proliferation of soft robots and actuators that exhibit improved capabilities and adaptability through three-dimensional (3D) bioprinting. Flexibility and shape recovery attributes of stimuli-responsive polymers as the main components in the production of these dynamic structures enable soft manipulations in fragile environments, with potential applications in biomedical and food sectors. Topology optimization (TO), when used in conjunction with 3D bioprinting with optimal design features, offers new capabilities for efficient performance in compliant mechanisms. In this paper, multimaterial TO analysis is used to improve and control the bending performance of a bioprinted soft actuator with electrolytic stimulation. The multimaterial actuator performance is evaluated by the amplitude and rate of bending motion and compared with the single material printed actuator. The results demonstrated the efficacy of multimaterial 3D bioprinting optimization for the rate of actuation and bending.

A forecasting model with hybrid bidirectional long short-term memory for mooring line responses of semi-submersible offshore platforms

Semi-submersible offshore platforms are often produced in the deep sea far away from land, which results in high operating costs and difficult safety maintenance due to the harsh and complex working conditions. Adopting a neural network model for online accurate prediction of mooring tension of semi-submersible offshore platforms can adjust the ballast according to the advance of mooring tension change to keep the platform in a relatively smooth movement amplitude and improve production efficiency. In addition, it can also prevent catastrophic accidents caused by anchor chain breakage due to excessive mooring tension. However, the measured mooring tension of semi-submersible offshore platforms is characterized by complex nonlinear non-stationarity, which leads to insufficient prediction accuracy of a single prediction model. This paper develops a novel online prediction model of mooring tension for semi-submersible offshore platforms based on empirical modal decomposition (EMD), convolutional neural network (CNN), and bidirectional long and short-term memory neural network (BiLSTM). The proposed model is validated using the measured data of the first semi-submersible offshore platform in the South China Sea during operation. The experimental results show that the proposed model outperforms other comparative models currently mainstream for mooring tension prediction. In addition, the proposed method can also be used to predict complex nonlinear data in the field of ship and ocean engineering.

Effects of various freak waves on dynamic responses of a Spar-buoy floating offshore wind turbine

There are various kind of waves in the actual ocean. Changes on freak wave profiles affect the motion of floating offshore wind turbines (FOWTs) and threaten the operation safety. To investigate this issue, the phase modulation method is used to simulate freak waves in our work. The original freak wave is first generated, then the wave profile is modulated to obtain five other types of freak waves, such as the reversed wave, the high-crested wave, the deep-troughed wave, the fluctuated wave, the elevated wave. A coupled time-domain model of a Spar-buoy FOWT is established to simulate the motion under steady wind and various freak waves. The dynamic responses are analyzed in the time domain, including the three-degree-of-freedom (3-DOF) motions of the floating foundation, the tension of mooring line and the nacelle acceleration. The frequency-domain properties under various freak waves are investigated using wavelet analysis. The effects of various wave profiles are compared with the original freak wave. Freak waves in low sea states are also generated to research their effects on pitch motion in different sea states. Results show that the response peaks increase in the impact region under freak waves. The reversed wave increases the maximum value of the 3-DOF motions, especially in pitch motion, and causes the high-frequency energy core of wavelet plots to move. The dynamic responses under the fluctuated wave combines the properties of increased response peaks at high-crested wave and increased amplitude of low-frequency motions at deep-troughed wave. The elevated wave greatly increases the heave motion of the FOWT. The increase in sea state level causes a nonlinear amplification in the transient oscillation.

Aerodynamic effects of an offshore floating photovoltaic platform undergoing pitch and heave motions

The offshore floating photovoltaic (OFPV) platform is a renewable energy generation system that has gained attention in recent years due to several advantages. OFPV exhibits higher sensitivity to wind loads than other offshore platforms, owing to its lightweight design and large aerial coverage. In contrast to the fixed photovoltaic systems, the OFPV platforms experience continuous oscillations induced by waves, which significantly influence the aerodynamic characteristics. In this study, the aerodynamic effects of an oscillating OFPV are investigated using the computational fluid dynamics (CFD) simulation method, including the three-dimensional effects, the Reynolds number effects, and the aerodynamic loads with various kinematic parameters. Some major findings are as follows. Firstly, a large-scale tip vortex exists when OFPV oscillates in pitch and heavy directions, which cannot be detected in two-dimensional simulations. Consequently, the lift coefficient, CL, and the drag coefficient, CD, are highly overestimated in 2-D simulation. Secondly, CL and CD decrease significantly as the Reynolds number increases for cases where Re < 106 while there is only a slight decrease for Re > 106. Thirdly, the aerodynamic forces are highly related to the amplitude of the pitch motion and the phase lag between the pitch and the heave motions. A fitting formula is proposed to calculate CL and CD based on the maximum angle of attack. Lastly, the evolution of the flow fields around the oscillating OFPV is analyzed. The separation of the leading edge mainly causes the aerodynamic force.

Flexural–torsional modal interaction in MEMS actuators initiated by minuscule asymmetry

AbstractAn efficient actuation technique for electrostatic MEMS actuators exploiting electro-mechanical-mechanical modal interactions is proposed. The flexural–torsional equations of motion are established, and we manifest that the initiation of a 2:1 autoparametric modal interaction between in-plane bending and torsional modes of the actuator that is supposed to be symmetrical with respect to its axis of rotation is contingent upon the presence of a quadratic stiffness term, which arises from the existence of non-zero first moments of area of the actual cross-section in prismatic microbeams. In order to efficiently reduce the AC voltage value required to reach the activation of the 2:1 mechanical modal interaction, the electrical resonant frequency is syntonized to half of the natural frequency of the in-plane bending mode. The results indicate that the amplitude of the in-plane motion saturates upon the initiation of an energy exchange between the bending and torsional motions. Through suitable tuning of the AC frequency, the amplitude of the in-plane motion is minimized, while the amplitude of the torsional motion, the indirectly excited mode, is maximized. Our results demonstrate that the actuator's torsional motion, when subjected to a 1:2:1 electro-flexural–torsional modal interactions, is triggered by applying a maximum voltage of 10 V, resulting in about 20 degrees rotational angle. Furthermore, prolific frequency combs are generated as a result of secondary Hopf bifurcations along the large-amplitude response branches, inducing quasi-periodicity in the MEMS dynamics.

Prognostic efficiency of diagnostic blockade as a method of modeling the result of selective neurotomy of the motor branches of the median nerve in patients with cerebral palsy

BACKGROUND: A feature of the disease course in patients with spastic cerebral palsy is a combination of motor neurological disorders with contractures in extremity joints. Neurosurgical methods are currently the main treatment for correcting the pathological tone of the “spastic hand.” However, the decreased tone does not affect secondary (fixed) contractures; therefore, the effectiveness of this type of treatment is extremely dependent on the accurate selection of a certain category of patients. Presumably, diagnostic blockade of the median nerve can create a reversible model for planned neurosurgical treatment. The inclusion of this technique as a standard for examining a patient with spastic cerebral palsy before invasive tone-lowering treatment can radically promote treatment effectiveness. AIM: This study aimed to assess the prognostic effectiveness of diagnostic blockade as a method of modeling the result of selective neurotomy of the motor branches of the median nerve in patients with cerebral palsy. MATERIALS AND METHODS: A longitudinal prospective study enrolled 39 children (aged 5–18 years) with spastic cerebral palsy. Before neurosurgical treatment, each patient underwent a diagnostic n. medianus under electrical stimulation and ultrasound control. After a diagnostic blockade, only patients who had a good functional and goniometric response were selected for the study, which served as an indication for selective neurotomy of the median nerve, and orthopedic treatment was performed in children with a negative event. Patients referred for neurotomy underwent a standardized examination before treatment during the diagnostic blockade and after neurosurgical treatment. The examination included the assessment of the amplitude of passive and active movements in the joints of the upper extremities, muscle tone, and functional capabilities of the upper extremities and dynamometry. RESULTS: In comparison with the initial data, a significant increase in the amplitude of passive and active hand extension, passive and active abduction of the first finger, and upper limb functional capabilities according to the MACS classification and the Miller scale was determined both after the diagnostic blockade and after selective neurotomy of the motor branches of the median nerve. CONCLUSIONS: Based on the results of the study, the effect of the diagnostic blockade and neurosurgical treatment outcomes are unidirectional, which allows the use of blockade as a method for modeling the possible result in clinically complex cases of spastic hand. The use of diagnostic blockade in clinical practice makes it possible to adequately assess the severity of fixed contractures and reduce the pathological hypertonicity of the target muscles. Diagnostic blockade allows for the collection of sufficient information to make an objective decision about which type of treatment is most preferable for each patient – neurosurgical, orthopedic, or sequential use of both methods.

Differential components of bradykinesia in Parkinson's disease revealed by deep brain stimulation.

Bradykinesia is a term describing several manifestations of movement disruption caused by Parkinson's disease (PD), including movement slowing, amplitude reduction, and gradual decrease of speed and amplitude over multiple repetitions of the same movement. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves bradykinesia in patients with PD. We examined the effect of DBS on specific components of bradykinesia when applied at two locations within the STN, using signal processing techniques to identify the time course of amplitude and frequency of repeated hand pronation-supination movements performed by participants with and without PD. Stimulation at either location increased movement amplitude, increased frequency, and decreased variability, though not to the range observed in the control group. Amplitude and frequency showed decrement within trials, which was similar in PD and control groups and did not change with DBS. Decrement across trials, by contrast, differed between PD and control groups, and was reduced by stimulation. We conclude that DBS improves specific aspects of movement that are disrupted by PD, whereas it does not affect short-term decrement that could reflect muscular fatigue.NEW & NOTEWORTHY In this study, we examined different components of bradykinesia in patients with Parkinson's disease (PD). We identified different components through signal processing techniques and their response to deep brain stimulation (DBS). We found that some components of bradykinesia respond to stimulation, whereas others do not. This knowledge advances our understanding of brain mechanisms that control movement speed and amplitude.

Liner orientation change of dual mobility cup determined via 3D ultrasound imaging and motion analysis: A cadaver study

BackgroundA mobile polyethylene liner enables the dual mobility cup (DMC) to contribute to restoring hip joint range-of-motion, decreasing wear and increasing implant stability. However, more data is required on how liner orientation changes with hip joint movement. As a first step towards better understanding liner orientation change in vivo, this cadaver study focuses on quantifying DMC liner orientation change after different hip passive movements, using ultrasound imaging and motion analysis. HypothesisThe liner does not always go back to its initial orientation and its final orientation depends mainly on hip movement amplitude. Methods3D ultrasound imaging and motion analysis were used to define liner and hip movements for four fresh post-mortem human subjects with six implanted DMC. Abduction and anteversion angles of the liner plane relative to the pelvis were measured before and after hip flexion, internal rotation, external rotation, abduction, adduction. ResultsLiner orientation changes were generally defined by angle variation smaller than 5°, with the liner nearly going back to its initial orientation. However, hip flexion caused liner abduction and anteversion angle variations greater than 15°. Except for hip adduction, only weak or no correlation was found between the final angle of the liner and the maximal hip joint movement amplitude. DiscussionThis study is the first attempt to quantify liner orientation change for implanted DMC via ultrasound imaging and constitutes a step forward in the understanding of liner orientation change and its relationship with hip joint movement. The hypothesis that the final liner abduction and anteversion angles depend mainly on hip movement amplitude was not confirmed, even if hip flexion was the movement generating the most liner orientation changes over 15°. This approach should be extended to in vivo clinical investigations, as measured liner angle variation could provide important support for the wear and stability claims made for DMC. Level of evidenceIV; cadaveric study.

Analysis of floating platform-mooring system-pile-soil interactions under wave loadings: A case study of the triangle-shaped semi-submersible platform

The floating platform-mooring system-pile-soil interactions under wave loadings represent a complex yet understudied aspect of floating offshore wind turbines (FOWTs). This paper presents the development and application of an Incompressible Material Point Method-Finite Element Method-Material Point Method (IMPM-FEM-MPM) model to simulate these interactions for a triangle-shaped semi-submersible platform (Tri-SSP), which serves as the foundation of China's first deep-sea FOWT, named ‘Fuyao.’ The proposed model is validated by studying the hydrodynamic responses of the OC4-DeepCwind platform. Under regular waves, increasing wave heights lead to heightened motion amplitudes, with the Tri-SSP exhibiting distinct phase differences between surge, pitch, and heave motions. Anchor Group 1 experiences significant peak tensions, ranging from 2.26 MN to 4.47 MN, which influence soil displacement, shear forces and bending moments along the pile shaft, emphasizing the impact of wave loading on pile-soil interactions. Under 1-h irregular waves, tension in Anchor Group 1 reaches extreme levels, with tensions up to 8 MN observed, underscoring the critical role of mooring systems in mitigating wave-induced forces. The calculated maximum stress within the pile indicates the structural integrity of the DH36 steel pile under these conditions. Comparisons of hydrodynamic responses, both with and without pile-soil interactions, show minimal discrepancies in motion amplitudes, indicating a minor influence on the dynamics of the platform and mooring system. These findings contribute to the understanding of complex interactions in deep-sea FOWTs, informing design and operational strategies for enhanced stability and performance.

Large eddy simulation and linear stability analysis of active sway control for wind turbine array wake

The convective instability of wind turbine wakes allows specific upstream forcing to amplify downstream, leading to increased wake meandering and replenishment, thereby providing a theoretical basis for active wake control. In this study, the active sway control—a strategy previously proven to enhance wake recovery at the single wind turbine level—is analyzed at the turbine array level. The similarity and differences between individual turbine wakes and the wake array are analyzed using large eddy simulations and linear stability analysis, considering both uniform and turbulent inflow conditions. For cases with uniform inflow, large eddy simulations reveal significant meandering motion in the wake array induced by active sway control at a motion amplitude of 1% rotor diameter, consistent with previous studies of standalone wind turbine wakes. Nevertheless, the sensitive frequency for the wake array extends down to St = 0.125 below the limit of St &amp;gt; 0.2 for a single wake, and the optimal control frequency for the standalone turbine wake becomes suboptimal for the array. Linear stability analysis reveals the underlying mechanism of this frequency shift as changes in the shear-layer instability due to the overlap of upstream and downstream wakes and is capable to provide fast estimation of optimal control frequencies. When inflow turbulence intensity increases, the gain of active sway control is reduced, underscoring the importance of low-turbulence environment for successfully implementing the active sway control. The reduction in wake response is captured by the linear stability analysis if the base flow accounts for the faster wake expansion caused by inflow turbulence.