Short-term effects of a new resistance exercise approach on physical function during chemotherapy after radical breast cancer surgery: a randomized controlled trial.

BACKGROUND: Approximately 30% of post-operative breast cancer patients develop shoulder joint movement disorders affecting routine upper limb movement. This study discusses the impact of a neuromuscular joint facilitation (NJF) method on the physical function of breast cancer patients experiencing shoulder dysfunction during chemotherapy after radical surgery. METHODS: This study included 162 female patients who have unilateral breast cancer in a cancer hospital in China. They developed shoulder joint mobility disorders during chemotherapy within 1-3 months postoperatively. These patients were divided into three groups: NJF, conventional rehabilitation (conventional group), and control groups. The clinical examination included the maximum passive and active range of motion (ROM) of the shoulder (flexion, extension, abduction, adduction, and external and internal rotation). Other evaluations included a pain score using a visual analog scale (VAS), grip strength, and supraspinatus muscle thickness. All tests were evaluated pre-and post-intervention. RESULTS: The NJF group showed a significant increase in all shoulder ROM angles post-intervention. In the conventional group, all other ROM values increased significantly, except passive external rotation ROM. In the control group, all other ROM values increased significantly, except passive and active external rotation ROM. All three groups had decreased VAS scores, increased grip strength, and supraspinatus muscle thickness post-intervention during active abduction. In the control group, the supraspinatus contraction rate decreased significantly at 60° and 90° abduction post-intervention compared to that at pre-intervention. CONCLUSION: This study revealed that NJF during chemotherapy had positive clinical intervention effects, improving shoulder joint mobility disorders, pain, grip strength, and external rotation following radical breast cancer surgery. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry; https://www.chictr.org.cn/ (ChiCTR2300073170), registered (03/07/2023).

Biomimetic Design of a New Semi-Rigid Spatial Mesh Antenna Reflector.

The reflective surface accuracy (RSA) of traditional space mesh antennas typically ranges from 0.2 to 6 mmRMS. To improve the RSA, an active control scheme can be employed, although it presents challenges in determining the installation position of the actuator. In this study, we propose a novel design for a semi-rigid cable mesh that combines rigid members and a flexible woven mesh, drawing inspiration from both rigid ribbed antennas and biomimicry. Initially, we investigate the planar mesh topology of spider webs and determine the bionic cable surface's mesh topology based on the existing hexagonal meshing method, with RSA serving as the evaluation criterion. Subsequently, through motion simulations and careful observation, we establish the offset angle as the key design parameter for the bionic mesh and complete the design of the bionic cable mesh accordingly. Finally, by analyzing the impact of the node quantity on RSA, we determine a layout scheme for the flexible woven mesh with a variable number of nodes, ultimately settling for 26 nodes. Our results demonstrate that the inclusion of numerous rigid components on the bionic cable mesh surface offers viable installation positions for the actuator of the space mesh antenna. The reflector accuracy achieved is 0.196 mmRMS, slightly surpassing the lower limit of reflector accuracy observed in most traditional space-space mesh antennas. This design presents a fresh research perspective on combining active control schemes with reflective surfaces, offering the potential to enhance the RSA of traditional rigid rib antennas to a certain extent.

The Factors Influencing Shoulder Mobility Disorders in Patients after Radical Breast Cancer Surgery: A Cross-Sectional Study.

Introduction: This study is a cross-sectional study that investigated the factors influencing shoulder mobility in terms of pain, grip strength, and supraspinatus muscle thickness in patients with impaired shoulder mobility during chemotherapy after radical breast cancer surgery. Methods: This study included 165 female patients with unilateral breast cancer who had shoulder joint mobility disorders during chemotherapy within 3 months after surgery. The clinical examination included the maximum active range of motion of the shoulder (flexion, extension, abduction, adduction, external rotation, and internal rotation), pain score (visual analog scale [VAS]), grip strength, and supraspinatus muscle thickness. Results: During shoulder abduction, supraspinatus muscle thickness was greatest at 90°, lowest at 0°, and higher at 60° than at 30° (p < 0.01). The factors influencing the active movement of shoulder flexion were the VAS score, body weight, grip strength, and supraspinatus contraction rate (R2 = 0.295), while the factors influencing active shoulder abduction were the VAS score, body weight, grip strength, supraspinatus muscle thickness (drooping position), and supraspinatus contraction rate (R2 = 0.295). Moreover, the factors influencing the active movement of shoulder external rotation were age, VAS score, body weight, grip strength, and supraspinatus muscle thickness (drooping position) (R2 = 0.258). There were no significant results from multiple linear regressions for shoulder extension, adduction, or internal rotation. Conclusion: Pain, weight, grip strength, supraspinatus muscle thickness, and supraspinatus distensibility are the main factors affecting shoulder flexion, abduction, and external rotation. In addition, supraspinatus muscle thickness and contraction rate may be a new index for assessing shoulder dysfunction.

Traditional Chinese exercises on pain and disability in middle-aged and elderly patients with lumbar disc herniation: a systematic review and meta-analysis of randomized controlled trials.

Background: Traditional Chinese exercises (TCEs) have played a significant role in treating various diseases. However, there is limited research assessing the efficacy of TCEs in treating Lumbar disc herniation (LDH). This study aimed to systematically evaluate the effects of four commonly used TCEs (Baduanjin, Yijinjing, Taichi, and Wuqinxi) on pain and disability in elderly patients with LDH. Objectives: To assess the quality of relevant randomized controlled trials (RCTs) to provide evidence support for the treatment of LDH. Methods: RCTs were identified through eight databases. Meta-analysis and trial sequence analysis (TSA) were conducted using RevMan 5.4, Stata 17.0, and TSA 0.9. Results: A total of 22 RCTs, involving 1931 patients, were included in the analysis. TCEs exhibited a superior effectiveness in treating LDH compared to the control group. However, the TSA analysis suggested the possibility of false positives, indicating the need for more high-quality RCT evidence. Nevertheless, TCEs showed reliable results in significantly improving the VAS score and JOA score of LDH patients. Conclusion: Current evidence indicates that the four TCEs have advantages in treating LDH in middle-aged and elderly individuals. However, considering the limitations of this study, we need to exercise caution in drawing conclusions, and further research is required to validate these findings. Systematic Review Registration: http://www.crd.york.ac.uk/PROSPERO, identifier [CRD42023431633].

Study on the mechanical parameters of neuromuscular joint facilitation rehabilitation techniques for lumbar intervention.

[Purpose] To measure the reliability of and quantify the force on the spinous process during lumbar neuromuscular joint facilitation using mechanical measuring gloves. [Participants and Methods] We recruited 12 healthy participants. The operator wore a mechanical measuring glove and performed evaluations in the four modes of neuromuscular joint facilitation of the lumbar spine. The mechanical glove was used to measure the force applied by the fingers on the spinous process during the intervention. [Results] The reliability of measuring the supraspinous force during lumbar neuromuscular joint facilitation with mechanical gloves was found to be good; the force was 30.9 ± 6.6 N for front lifting, 37.1 ± 9.1 N for rear descent, 36.8 ± 9.0 N for forward descent, and 24.6 ± 4.7 N for rear lifting. Overall, the average force was 32.3 ± 9.0 N. No statistical difference was observed between passive and resistance motion. [Conclusion] This study confirmed that the measurement of the force on the spinous process in lumbar neuromuscular joint facilitation using mechanical measurement gloves has good reliability. Furthermore, we determined the average force exerted on the spinous process during lumbar neuromuscular joint facilitation and quantified the operation specifications of this manipulation were.

Immediate effects of neuromuscular joint-facilitation bridging exercises on walking ability and balance function in stroke patients.

[Purpose] This study aimed to examine the immediate effects of a pelvic neuromuscular joint-facilitation intervention on the walking and balance ability of patients with hemiplegia caused by cerebrovascular accidents. [Participants and Methods] A total of 15 patients with hemiplegia caused by cerebrovascular accidents underwent a neuromuscular joint-facilitation lumbar-pattern intervention (intervention group), a bridge exercise (bridge intervention group), or a neuromuscular joint-facilitation bridge intervention (neuromuscular joint-facilitation bridge group). Each intervention was randomly administered at 7-day intervals. Measurement items included the timed up-and-go test, functional reach test, 10-m maximum walking speed test, and load in the standing position. Measurements were taken before and after the intervention in each group. [Results] The timed up-and-go test result was significantly shorter in the neuromuscular joint-facilitation intervention group. Timed up-and-go test results, functional reach, 10-m walking time, and standing load (non-paralyzed side) significantly improved in the neuromuscular joint-facilitation bridge group. [Conclusion] The neuromuscular joint-facilitation bridge intervention was immediately effective in patients with hemiplegia caused by cerebrovascular accidents and improved their walking and balance ability.

The reliability and effectiveness of shoulder joint evaluation by ultrasonography in stroke patients: deltoid muscle thickness, acromion-humeral distance, acromion-lesser tuberosity distance.

[Purpose] This study aimed to evaluate the reliability of the intraclass correlation coefficient (ICC) in measuring deltoid muscle thickness (DMT) at different angles, acromion-humeral distance (AHD), and acromion nodule tuberosity (ALT) distance in a resting position in stroke patients using ultrasonography. [Participants and Methods] We included 40 stroke patients. During the measurement of parameters by ultrasonography, we measured the deltoid muscle thickness on both sides at three test angles (0°, 30°, and 60° abduction) and AHD and ALT on both sides at 0° angle. The ICC was used to assess intra- and interrater reliability. The relationship between the hemiplegic and non-hemiplegic sides and each angle were analyzed using a two-way repeated-measure analysis of variance (ANOVA). [Results] When the shoulders were at three testing angles (0°, 30°, and 60° abduction), the deltoid muscle thickness of the hemiplegic and non-hemiplegic sides showed good reliability; the AHD and ALT of the shoulder joint at 0° angle equally showed good reliability. There was a significant difference in each abduction angle of the shoulder joint between the thickness of the hemiplegic and non-hemiplegic deltoid. [Conclusion] Measuring deltoid muscle thickness by ultrasonography showed excellent reliability and can be used in stroke patients.

Evaluation of supraspinatus muscle changes in the shoulder joint of stroke patients with hemiplegic and shoulder subluxation using ultrasonography: comparison between affected and unaffected sides.

[Purpose] The shoulder joint has a very unstable structure yet a significantly wide range of motion. Weakness of the muscles around the shoulder joint may cause shoulder joint subluxation. This study aimed to determine changes in supraspinatus muscle thickness between different shoulder abduction angles using ultrasonography and to compare differences in supraspinatus muscle thickness changes between the affected and unaffected sides depending on shoulder joint subluxation. [Participants and Methods] Forty hemiplegic patients with stroke were recruited (20 patients with and 20 without shoulder subluxation). Using ultrasonography, we measured supraspinatus muscle thickness at three shoulder joint abduction angles and calculated the differences in supraspinatus muscle thickness. Depending on subluxation, we separately analyzed the thickness and variations in the supraspinatus muscle on both the affected and unaffected sides. [Results] In stroke patients with shoulder subluxation, the difference in supraspinatus muscle thickness was significantly less in the affected side than in the unaffected side. [Conclusion] The thickness and rate of supraspinatus muscle thickness change was significantly less in the affected side than in the unaffected side in stroke patients with shoulder subluxation.

Research on Joint-Angle Prediction Based on Artificial Neural Network for Above-Knee Amputees.

In the current study, our research group proposed an asymmetric lower extremity exoskeleton to enable above-knee amputees to walk with a load. Due to the absence of shank and foot, the knee and ankle joint at the amputation side of the exoskeleton lack tracking targets, so it is difficult to realize the function of assisted walking when going up and downstairs. Currently, the use of lower-limb electromyography to predict the angles of lower limb joints has achieved remarkable results. However, the prediction effect was poor when only using electromyography from the thigh. Therefore, this paper introduces hip-angle and plantar pressure signals for improving prediction effect and puts forward a joint prediction method of knee- and ankle-joint angles by electromyography of the thigh, hip-joint angle, and plantar pressure signals. The generalized regression neural network optimized by the golden section method is used to predict the joint angles. Finally, the parameters (the maximum error, the Root-Mean-Square error (RMSE), and correlation coefficient (γ)) were calculated to verify the feasibility of the prediction method.

Curative effect of long-term intervention using a new device in patients with chronic low back pain.

[Purpose] This study aimed to observe the changes in the thickness of the transverse abdominis muscle after long-term training with a new device using ultrasound imaging and to determine the impact of these changes on chronic low back pain (CLBP). [Participants and Methods] This study included 60 participants with CLBP, who were divided into groups that adopted different positions during the training regimen: new device intervention group (NDG), sitting training group (STG), and supine training group (SPTG). Patients in the NDG used the new device during training. We measured the thickness of the transverse abdominis muscle and determined the pain level using the visual analog scale (VAS). [Results] After 8 weeks of training, the thickness of the transverse abdominis muscle changed in all the three groups, with the change being significantly greater in the NDG than in the other groups. Additionally, the VAS results indicated that the pain relief was highest when the new device was used. [Conclusion] The thickness of the transverse abdominis muscle increased the most in patients who were trained with the new interventional device, and the CLBP was significantly relieved in them.

Analysis of the relationship between the transversus abdominis and lower back pain using an ultrasound.

[Purpose] This study aimed to observe the thickness of the transverse abdominis muscle in different contraction states using ultrasound, and to investigate the diagnostic capability of transverse abdominal muscle thickness for nonspecific lower back pain. [Participants and Methods] This study included 108 healthy adults (30-50 years old), consisting of 33 participants with low back pain (13 males, 20 females; defined as those who had experienced low back pain for more than six months) and 75 participants without low back pain (22 males, 53 females). The body mass index, body trunk muscle mass, and transverse abdominal muscle thickness, measured at a static state, during the end of inspiration, end of expiration, transverse abdominis contraction, and simultaneous pelvic floor and transverse abdominis muscle contraction, were measured. [Results] Chronic low back pain was correlated with the transverse abdominis muscle thickness during simultaneous transverse abdominis and pelvic floor muscle contraction. [Conclusion] The thickness of the transverse abdominis muscle during simultaneous transverse abdominis and pelvic floor muscle contraction was a viable diagnostic index for evaluating the degree of chronic lower back pain.

Effect of Cooling Method on Formability of Laser Cladding IN718 Alloy.

The finite element model (FE) of temperature field of straight thin-walled samples in laser cladding IN718 was established, and the growth of microstructure was simulated by cellular automata (CA) method through macro-micro coupling (CA-FE). The effects of different cooling conditions on microstructure, hardness, and properties of laser-cladding layer were studied by designing cooling device. The results show that the simulation results are in good agreement with the microstructure of the cladding layer observed by the experiment. With the scanning strategy of reducing laser power layer-by-layer, the addition of water cooling device and the processing condition of 0.7 mm Z-axis lift, excellent thin-walled parts can be obtained. With the increase of cladding layers, the pool volume increases, the temperature value increases, the temperature gradient, cooling rate, solidification rate, K value gradually decrease, and eventually tend to be stable, in addition, the hardness shows a fluctuating downward trend. Under the processing conditions of layer-by-layer power reduction and water cooling device, the primary dendrite arm spacing reduced to about 8.3 µm, and the average hardness at the bottom of cladding layer increased from 260 HV to 288 HV. The yield strength and tensile strength of the tensile parts prepared under forced water cooling increased to a certain extent, while the elongation slightly decreased.

Effect of Vanadium Content on the Microstructure and Mechanical Properties of IN718 Alloy by Laser Cladding.

Microalloying vanadium can change the segregation state of Nb element in IN718 alloy, reduce the formation of harmful Laves phase and refine the dendritic structure of IN718 alloy during the laser process. Therefore, IN718 alloys with V content from 0.081 to 1.88 wt.% were prepared and evaluated. Metallographic microscopy and scanning electron microscopy were used to observe the corresponding morphology, structure, and distribution of elements. First of all, it was found that the addition of V refines the grain size of IN718 alloy and reduces the primary dendrite arm spacing. Secondly, adding V to IN718 alloy can reduce the porosity of the cladding layer. The elements are uniformly distributed in the cladding layer, and the addition of vanadium reduces the segregation degree of the Nb element, which is conducive to homogenization. In addition, microhardness and residual stress were also investigated. Finally, the addition of vanadium was shown to have no apparent effect on the tensile strength and yield strength but can significantly improve the elongation of IN718 alloy. In conclusion, the microstructure and mechanical properties of IN718 alloy with 0.081 wt.% vanadium content provide a new solution to improve the application level of IN718 alloy in laser cladding.

Investigation on the Microporosity Formation of IN718 Alloy during Laser Cladding Based on Cellular Automaton.

Porosity is one of the most common defects in the laser cladding of Inconel 718 (IN718) alloy, which can reduce the strength and fatigue performance of the components. However, the dynamic formation of microporosity is challenging to observe through experiments directly. In order to explore the formation mechanism of porosities and dynamically reproduce the competitive growth between porosities and dendrite, a multi-scale numerical model was adopted, combined with a cellular automaton (CA) and finite element method (FEM). The decentered square algorithm was adopted to eliminate crystallographic anisotropy and simulate dendrite growth in different orientations. Afterward, based on the formation mechanism of microporosity during solidification, equiaxed and columnar dendrites with porosities were simulated, respectively. Dendrite morphology, porosity morphology, and distribution of solute concentration were obtained during the solidification process. The simulation results were reasonably compared with experimental data. The simulation results of the equiaxed crystal region are close to the experimental data, but the columnar crystal region has a relative error. Finally, the interaction effects of porosities and dendrites under different environmental conditions were discussed. The results suggested that with the increase in the cooling rate, the quantity of porosity nucleation increased and the porosity decreased.

Reliability of ultrasonographic measurement of the supraspinatus thickness at different angles of shoulder abduction in patients with stroke.

[Purpose] The primary purpose of this study was to evaluate the usefulness of the intraclass correlation coefficient for evaluating the reliability of the measurement of the supraspinatus thickness on shoulder ultrasonography at different angles in a resting position in patients with stroke. [Participants and Methods] The study included 20 patients with stroke. The supraspinatus thickness was measured on both sides on ultrasonography, with the participants' shoulders in abduction at 3 testing angles (0°, 30°, and 60° abduction). Each measurement was performed three times, and the average of the three measurements was recorded. The intraclass correlation coefficient was calculated, with the supraspinatus thickness measured twice at an interval of 24 hours as the factor. [Results] All intraclass correlation coefficients for the hemiplegic and normal sides were greater than 0.93 when the shoulders were at the three testing angles. [Conclusion] In this investigation, the reliability of measuring the supraspinatus thickness on shoulder ultrasonography at each angle for 3 times was evaluated and was found to be excellent.

Prediction of Limb Joint Angles Based on Multi-Source Signals by GS-GRNN for Exoskeleton Wearer.

To enable exoskeleton wearers to walk on level ground, estimation of lower limb movement is particularly indispensable. In fact, it allows the exoskeleton to follow the human movement in real time. In this paper, the general regression neural network optimized by golden section algorithm (GS-GRNN) is used to realize prediction of the human lower limb joint angle. The human body hip joint angle and the surface electromyographic (sEMG) signals of the thigh muscles are taken as the inputs of a neural network to predict joint angles of lower limbs. To improve the prediction accuracy in different gait phases, the plantar pressure signals are also added into the input. After that, the error between the prediction result and the actual data decreases significantly. Finally, compared with the prediction result of the BP neural network, GRNN shows splendid prediction performance for its less processing time and higher prediction accuracy.

Thermal Deformation of PA66/Carbon Powder Composite Made with Fused Deposition Modeling.

Polyamide 66 (PA66) is a material with high wear resistance, toughness, and heat resistance. However, low stiffness and thermal deformation during thermal processes define applications in many conditions. Carbon powder efficiently enhances stiffness and reduces thermal deformation, which makes up defects of plastic materials. However, forming a composite with fused deposition modeling (FDM) that accumulates material to a specified location by melting plastic filaments is limited, including fluidity and viscosity to form normally. In this paper, filaments of polyamide 66 (PA66) reinforced with carbon powder were produced. Digimat was used to analyze the composite material properties of different carbon contents and predict the proper carbon content. Then, the material properties were imported to ANSYS software to simulate the thermal deformation of the workpieces during processing. It was verified that adding carbon powder is helpful in decreasing thermal deformation. Comparing experiments and simulations, we found that 20% carbon mass fraction was best, and that thermal deformation was minimal at 240 °C nozzle temperature while hot bed temperature was 90 °C. The optimal ratio of extrusion speed to filling speed was 0.87, and the best aspect ratio was 0.25.

Influence of Vanadium on the Microstructure of IN718 Alloy by Laser Cladding.

A deleterious Laves phase forms in the solidified structure of Inconel 718 (IN718) alloy during laser cladding. However, effective removal methods have not yet been identified. In this study, we first added the IN718 alloy cladding layers with a trace amount of vanadium (V, 0.066 wt.%). Then, we studied the solidification structure of cladding layers using a confocal laser scanning microscope and scanning electron microscopy. The microstructure and Laves phase morphology were investigated. The distribution of niobium (Nb) was observed by experiment as well. We found that V is evenly distributed in dendrites and interdendritic zones. A more refined dendrite structure, reduced second dendrite arm spacing and lower volume fraction of Laves phase were observed in the solidification structure. The results of linear energy-dispersive X-ray spectroscopy (EDS) indicate that the concentration of Nb decreases with an increasing of the distance from the Laves phase. The V-containing sample displayed a relatively slower decreasing tendency. The IN718 alloy sample was harder with the addition of V. In addition, the porosity of the sample decreased compared with the blank sample. The presented findings outline a new method to inhibit the Nb segregation in IN718 alloy during laser cladding, providing reference significance for improving the performance of IN718 alloy samples during actual processing.

Immediate effects of lumbar spine patterns after neuromuscular joint facilitation on balance in stroke patients.

[Purpose] The present study investigated changes in the balance function of stroke patients after neuromuscular joint facilitation treatment. [Participants and Methods] Fourteen stroke patients were randomly subjected to neuromuscular joint facilitation intervention (neuromuscular joint facilitation intervention group) and no intervention (control group), with a 1-day interval between treatments. The interventions were performed consecutively. The order of interventions was completely randomized. Before and after one neuromuscular joint facilitation and control intervention, the functional reach test, and body sway were measured. [Results] Functional reach test values were significantly increased and peripheral area was significantly reduced in the neuromuscular joint facilitation intervention group than in the control group. [Conclusion] These results suggest that neuromuscular joint facilitation of the trunk has an immediate effect on balance and function in stroke patients.