Single Joint Research Articles

A Review of Bee Venom Acupuncture for Articular Diseases of Single Type Joint in the Journal of Korean Medicine

Hyo-Jun Kim, K.M.D.*, Gook-Beom Kim, K.M.D.*, Joon Park, K.M.D.*, Yong-Su Kwon, K.M.D.*, Jae-eun Yu, K.M.D.*, Hee-Won Lee, K.M.D.*, Jun-Hyo Bae, K.M.D.*, Gyu-Cheol Choi, K.M.D.†, Ji-Eun Bae, K.M.D.†, Su-Bin Han, K.M.D.‡, Yang-Sun Kim, K.M.D.§. J Korean Med Rehabi 2021;31:119-35. https://doi.org/10.18325/jkmr.2021.31.1.119

A Closed-Form Solution for the Inverse Kinematics of the 2n-DOF Hyper-Redundant Manipulator Based on General Spherical Joint

This paper presents a closed-form inverse kinematics solution for the 2n-degree of freedom (DOF) hyper-redundant serial manipulator with n identical universal joints (UJs). The proposed algorithm is based on a novel concept named as general spherical joint (GSJ). In this work, these universal joints are modeled as general spherical joints through introducing a virtual revolution between two adjacent universal joints. This virtual revolution acts as the third revolute DOF of the general spherical joint. Remarkably, the proposed general spherical joint can also realize the decoupling of position and orientation just as the spherical wrist. Further, based on this, the universal joint angles can be solved if all of the positions of the general spherical joints are known. The position of a general spherical joint can be determined by using three distances between this unknown general spherical joint and another three known ones. Finally, a closed-form solution for the whole manipulator is solved by applying the inverse kinematics of single general spherical joint section using these positions. Simulations are developed to verify the validity of the proposed closed-form inverse kinematics model.

Numerical modeling of jointed rock samples under unconfined and confined conditions to study peak strength and failure mode

The presence of weak planes in most rock masses reduces their strength and changes their mechanical behavior. Jaeger’s plane of weakness theory is a simple model for predicting the strength of jointed rock samples. This model proposes a U-shaped curve for the strength of the jointed rock samples. In this paper, using the discrete element method, several two-dimensional models of the jointed rock samples are analyzed, and their results are compared with Jaeger’s plane of weakness theory. According to the results, if the sample has one or two parallel joints, the strength obtained from the numerical method corresponds to the analytical model. However, if the sample has two intersecting symmetrical joints, the concentration of stress created at the vertices of the rock blocks increases the strength of the sample, In this case, the sample strength is 80% on average higher than that of the sample with a single joint. If the sample has three or four intersecting joints with an angle of 30° to each other, the strength of the sample based on numerical solution is 36% and 40% less than the theoretical solution, respectively. In this case, because the sample is divided into several small parts, the strength of the sample is reduced and less than the theoretical model. Numerical analysis provides strength and failure mode for jointed rock samples more accurately, which will certainly be useful in designing underground structures located in jointed rock environments.

Synovitis and Tenosynovitis on Ultrasound as Predictors of DMARD Tapering Failure in Patients with Long-Standing Rheumatoid Arthritis in Clinical Remission or Low Disease Activity.

This study aimed to investigate the predictive value of synovitis and tenosynovitis detected by grayscale (GS) and by power Doppler (PD) ultrasound (US) in relation to failure of tapering disease-modifying antirheumatic drugs (DMARD) in rheumatoid arthritis (RA) patients. Long-standing RA patients who de-escalated treatment were included in this prospective cohort study. All patients underwent 3 ultrasonographic and clinical assessments, at baseline and every 3 or 4 months, over a period of 6-8 months. US investigation of 32 joints was performed. Synovitis was assessed by GS and PD semiquantitative scoring (0-3) and a global score was calculated for each individual by summing single joint scores. The presence of tenosynovitis was recorded whenever detected during ultrasound assessment. Thirty-three patients completed the follow-up period (29 women; 4 men). Eight patients (25%) relapsed. Using the optimal cutoff values determined by receiver operating characteristic curve, patients with a PD synovitis ≥1 at baseline had significantly greater chances to relapse than those without PD activity. During follow-up, GS tenosynovitis was detected in 6 patients (5 with PD) who failed and in 3 patients (1 with PD) who succeeded in tapering therapy. Having at least 1 joint with PD synovitis resulted in a relative risk of 3.14 and having GS tenosynovitis resulted in a relative risk of 11.4 (95% CI: 1.03-9.60 and 2.82-45.9, respectively) for relapse in the multivariate Poisson model. PD synovitis and GS tenosynovitis may be useful to identify RA patients in risk of relapse after DMARD tapering.

Effects of tensile stresses on wave propagation across stylolitic rock joints

External stresses, i.e., compressive, shear and tensile stresses, strongly affect seismic wave propagation across rock joints. The present study experimentally investigates the effects of tensile stresses on wave behaviors across single natural rock joints by simultaneously conducting ultrasonic measurements and direct tensile tests. Laboratory results show that increasing tensile stress causes decreases in transmission coefficient and spectral amplitudes for both ultrasonic P- and S-waves. Additionally, for the weaker joint under tension, wave velocity is evidently reduced by the increasing tensile stress. The comparison of measured spectra with theoretically predicted spectra indicates that ultrasonic wave properties of single rock joints under tension could be well described by the displacement discontinuity model (DDM). It is also found that values of joint static and dynamic specific stiffness decrease with increasing tensile stress.

Quantifying Coordination and Variability in the Lower Extremities after Anterior Cruciate Ligament Reconstruction.

Patients experience various biomechanical changes following reconstruction for anterior cruciate ligament (ACL) injury. However, previous studies have focused on lower extremity joints as a single joint rather than simultaneous lower extremity movements. Therefore, this study aimed to determine the movement changes in the lower limb coordination patterns according to movement type following ACL reconstruction. Twenty-one post ACL reconstruction patients (AG) and an equal number of healthy adults (CG) participated in this study. They were asked to perform walking, running, and cutting maneuvers. The continuous relative phase and variability were calculated to examine the coordination pattern. During running and cutting at 30 and 60°, the AG demonstrated a lower in-phase hip–knee coordination pattern in the sagittal plane. The AG demonstrated low hip–knee variability in the sagittal plane during cutting at 60°. The low in-phase coordination pattern can burden the knee by generating unnatural movements following muscle contraction in the opposite direction. Based on the results, it would be useful to identify the problem and provide the fundamental evidence for the optimal timing of return-to-sport after ACL reconstruction (ACLR) rehabilitation, if the coordination variable is measured with various sensors promptly in the sports field to evaluate the coordination of human movement.

Verification and Regularization Method for 3D-Human Body Pose Estimation based on Prior Knowledge

Applications used in human-centered scene analysis often rely on AI processes that provide the 3D data of human bodies. The applications are limited by the accuracy and reliability of the detection. In case of safety applications, an almost perfect detection rate is required. The presented approach gives a confidence measure for the likelihood that detected human bodies are real persons. It measures the consistency of the estimated 3D pose information of body joints with prior knowledge about the physiologically possible spatial sizes and proportions. Therefore, a detailed analysis was done which lead to the development of an error metric that allows the quantitative evaluation of single limbs and in summary of the complete body. For a given dataset an error threshold has been derived that verifies 97% persons correctly and can be used for the identification of false detections, so-called ghosts. Additionally, the 3D-data of single joints could be rated successfully. The results are usable for relabeling and retraining of underlying 2D and 3D pose estimators and provides a quantitative and comparable verification method, which improves significantly a reliable 3D-recognition of real persons and increases hereby the possibilities of high-standard applications of 3D human-centered technologies.

Simulating flow in rock joints using a particulate interface model of a discrete element method

This study proposes a fluid flow algorithm incorporated with the particulate interface model (PIM) to simulate flow in rock joints in the particulate DEM. The PIM captures the mechanical behavior of a rock joint based on macroscopic parameters, and then the fluid flow algorithm calculates correct flow behavior in rock joint. In the fluid flow algorithm, a virtual pore space is defined as the area that is surrounded by adjacent particles in contacts. A series of pore spaces are connected to form a flow channel along a joint, and fluid is only transmitted in the designated joint. A series of numerical flow tests through a joint under different normal and shear stresses are conducted. A comparison of analytical solutions under different times and hydraulic conductivities reveals that the proposed model can simulate flow in a single joint in both steady and transient states. In addition, two cases that involve multiple joints are simulated to investigate the application of the PIM with the modified fluid flow algorithm. Finally, a fully hydraulic-mechanical–coupled analysis is conducted; the results demonstrate that the proposed model reasonably simulates flow in a generalized fracture network.

Imperfections and Modelling of the Weld Bead Profile of Laser Butt Joints in HSLA Steel Thin Plate

In many applications that use high strength steels, structural integrity depends greatly on weld quality. Imperfections and the weld bead geometry are influencing factors on mechanical properties of the welded joints but, especially in the fatigue strength, they cause a great decrease. The proper knowledge of these two factors is important from the nominal stress approach to the fracture mechanics approaches. Studies concerning the profile and imperfections of the weld bead in laser welding for thin plates of high strength steels are scarce. In this work, these two aspects are covered for five series single and double-welded joints, butt joints in a 3 mm thick HSLA steel, welded in a small range of welding parameters. The actual profiles captured with profilometer were modeled with proposed geometric parameters achieving an adequate fit with values of the coefficient of determination ℜ2 greater than 0.9000. Description of imperfections includes the distributions of porosity and undercuts. The evaluation of the weld quality, taking as guide the ISO 13919-1 standard determined B and D levels for the welded series while based on the stress-concentrating effect, showed a greater detriment in those series with undercuts and excessive penetration. The analysis of variance validated the results of the different combinations of laser welding parameters and showed, for the factorial experimental design, a more significant effect of the welding speed.

Structure and Pathologies of Articular Cartilage.

The aim of the review was to describe a complex microstructure and biomechanical properties of the articular cartilage as well as a current review of its pathologies encountered in veterinary practice. The articular cartilage with its unique features: complex microarchitecture, significant mechanical durability and elasticity, lacking blood, lymphatic vessels, and innervation, seems to stand in contradiction to the laws of biology. It can be involved in a vast majority of diseases, from osteoarthrosis as a result of natural aging process to more complex in nature like osteochondromatosis. The primary role of articular cartilage is to provide the surface for movement in any single joint in the body. Therefore, its diseases lead to physical impairment and deterioration of the quality of life. Treatment of articular cartilage poses a formidable challenge in both modern human and animal medicine.

СОВРЕМЕННОЕ СТРАТЕГИЧЕСКОЕ ВИДЕНИЕ, НЕОБХОДИМОЕ ДЛЯ РАЗВИТИЯ ТЕРРИТОРИАЛЬНОЙ КЛАСТЕРНОЙ ПОЛИТИКИ

The article analyzes and evaluates the role of territorial cluster policy as a factor of growth of the Russian economy, which ultimately contributes to the creation of a new technological basis for overcoming turbulence in the modern Russian economy and solving problems of coordination of actions on a global scale. The article analyzes the model of formation of territorial cluster policy in the system of network partners implementing collective actions in a single territory, common identity and joint commitments in the aspect of cluster business formation in order to select priority areas in the development of science, technology and digital technologies that should be aimed at modernizing the economy in order to increase its competitiveness. The article analyzes that the formation of digital territorial clusters multiplies the productivity of production factors and serves as the main mechanism for balancing the economy in the context of globalization.

Charcot foot – current concepts

Charcot neuropathic osteoarthropathy (CNO) is painless, progressive, noninfectious, degenerative arthropathy affecting single or multiple joints and soft tissues of foot and ankle caused by an underlying neurological deficit. The primary indication for surgical correction is a nonbraceble, nonplantigrade foot, instability, and impending or established ulceration. The goal of surgical management is to provide a stable, ulcer-free, plantigrade foot that can accommodate therapeutic footwear for self-ambulation. The choice of implants in midfoot CNO can be a combination of plate and screws well beyond the area of deformity to achieve rigid stability and good alignment following the principle of a super construct. The deformities involving the talus and ankle joint require a Total contact casting (TCC) arthrodesis, preferably with an intramedullary nail. The choices for soft tissue coverage as an additional procedure for ulcer management are guided by anatomic location, size, depth of ulcer, condition of surrounding soft tissue, and underlying deformity.

Transmission spectrum characteristics of Lamb waves at single lap adhesive joints

Transmission spectrum characteristics of Lamb waves at single lap adhesive joints

Gyro movement equations

In this work the motion equations of a gyro with essential characteristics were constructed, where the rotor rotates to reason ψ around an axis mounted on a single universal joint, which can rotate freely around the vertical axis. The angle formed by the rotor shaft and the plane of the meridian is denoted with θ, latitude, the angle of the position on earth is denoted λ and with ωe the angular velocity of the Earth around its axis.Based on the formulation of Lagrange, the motion equations governing this system were obtained, differential equations were also solved with the standardized Runge-Kutta method of order 4. Also, we present several phase spaces that show the temporal evolution of the system.

Single limb cable driven wearable robotic device for upper extremity movement support after traumatic brain injury.

IntroductionRecently, soft exosuits have been proposed for upper limb movement assistance, most supporting single joint movements. We describe the design of a portable wearable robotic device (WRD), “Armstrong,” able to support three degrees-of-freedom of arm movements, and report on its feasibility for movement support of individuals with hemiparesis after traumatic brain injury (TBI).MethodsWe introduce Armstrong and report on a pilot evaluation with two male individuals post-TBI (T1 and T2) and two healthy individuals. Testing involved elbow flexion/extension with and without robotic-assisted shoulder stabilization; shoulder abduction with and without robotic-assisted elbow stabilization; and assisted shoulder abduction and flexion. Outcome measures included range of motion and root mean square trajectory and velocity errors.ResultsTBI subjects performed active, passive, hybrid and active assistive movements with Armstrong. Subjects showed improvements in movement trajectory and velocity. T1 benefited from hybrid, active, and assistive modes due to upper extremity weakness and muscle tone. T2 benefited from hybrid and assistive modes due to impaired coordination. Healthy subjects performed isolated movements of shoulder and elbow with minimal trajectory and velocity errors.ConclusionsThis study demonstrates the safety and feasibility of Armstrong for upper extremity movement assistance for individuals with TBI, with therapist supervision.

An Experimental and Numerical Investigation on Bolted Joints of Woven Glass Fabric/Epoxy Composites

In the present work, an attempt is made to study the mechanical response of woven glass fabric/epoxy composite laminates using numerical modelling and experimentation. For this two different configurations namely double lap joined with single and double bolts are chosen. These laminates are subjected to numerical modelling using finite element analysis to study the joint strength and stress analysis. The joint strength of woven glass fabric composites is studied experimentally by conducting tensile test. Along with this the effect of varying edge distance to diameter ratios are studied both numerically and experimentally to arrive at safe design. Both numerical analysis and experimentally obtained bearing strength of composite laminated bolted joints are correlated. This is done in order to predict the the failure load and failure mechanisms in the composite laminate bolted joints. The variation in the numerically and experimentally obtained bearing strength values were well within 5% diference for both cases of single and double bolted joints.

Although Surgical Techniques Differ, Similar Outcomes Can Be Obtained When Operating After Single Versus Multiple Anterior Shoulder Dislocations

PurposeTo compare the differences in preoperative pathology, surgical technique, and overall outcomes between patients treated surgically after a single anterior glenohumeral joint dislocation and those undergoing surgery after multiple dislocations.MethodsAn epidemiologic database was used to identify all patients younger than 40 years undergoing surgery for anterior shoulder instability between January 1, 1994, and July 31, 2016, in a defined geographic area. Patient medical records were reviewed to obtain demographic information, patient history, physical examination findings, imaging findings, clinical progression, surgical details, and outcomes. Comparative analysis was performed between patients who underwent surgery after a single dislocation and those who underwent surgery after multiple preoperative dislocations.ResultsThe study population consisted of 187 patients who had a single anterior shoulder dislocation (n = 55) or multiple anterior shoulder dislocations (n = 132) prior to surgery. The mean follow-up period was 103.3 months (range, 0.3-328.4 months). Demographic characteristics were not significantly different between groups. Although the presence of Hill-Sachs lesions on radiographs was more common in the multiple-dislocation group (42.1%) than in the single-dislocation group (18.8%, P = .005), there were no other significant differences in concomitant pathology between groups. Latarjet procedures were more commonly performed in the multiple-dislocation group (12.5% vs 2.1% in the single-dislocation group, P = .04). There were no other significant differences in surgical techniques and characteristics between groups. Rates of survival free from recurrent instability (P = .790), revision surgery (P = .726), and progression to symptomatic osteoarthritis (P = .588) were not significantly different between groups.ConclusionsAlthough patients with multiple dislocations prior to surgery were more likely to show radiographic evidence of Hill-Sachs lesions and undergo the Latarjet procedure than those who received surgery after a single dislocation, no significant differences in outcomes with respect to recurrent instability, revision surgery, or progression to symptomatic osteoarthritis were found between these 2 groups at long-term follow-up.Level of EvidenceLevel III, retrospective comparative study.

Structure and Hierarchy of SARS-CoV-2 Infection Dynamics Models Revealed by Reaction Network Analysis.

This work provides a mathematical technique for analyzing and comparing infection dynamics models with respect to their potential long-term behavior, resulting in a hierarchy integrating all models. We apply our technique to coupled ordinary and partial differential equation models of SARS-CoV-2 infection dynamics operating on different scales, that is, within a single organism and between several hosts. The structure of a model is assessed by the theory of chemical organizations, not requiring quantitative kinetic information. We present the Hasse diagrams of organizations for the twelve virus models analyzed within this study. For comparing models, each organization is characterized by the types of species it contains. For this, each species is mapped to one out of four types, representing uninfected, infected, immune system, and bacterial species, respectively. Subsequently, we can integrate these results with those of our former work on Influenza-A virus resulting in a single joint hierarchy of 24 models. It appears that the SARS-CoV-2 models are simpler with respect to their long term behavior and thus display a simpler hierarchy with little dependencies compared to the Influenza-A models. Our results can support further development towards more complex SARS-CoV-2 models targeting the higher levels of the hierarchy.

Postoperative Ultrasound as a Predictor of Newborn Function and Ambulation after Open Fetal Myelomeningocele Repair

Objective: Function of the lower extremities after prenatal myelomeningocele (MMC) repair is best assessed with ambulatory function at 30–36 months of age, but parents often ask about function before this milestone. Lower extremity movement can be assessed by ultrasound (US) and at the newborn exam (NE), but correlation between US, NE, and ambulation is not firmly established. Methods: This was a retrospective correlation study of fetuses that underwent open prenatal MMC repair at SSM Cardinal Glennon Fetal Care Institute, St. Louis, MO, between January 2011 and June 2017. Movement at the ankles, knees, and hips was assessed by US after open repair on postoperative days (PODs) 0–5 and at 32 weeks gestation. NE was performed by physical therapy or neurosurgery within the first month of life, and pediatric follow-up between 30 and 36 months of age was obtained to document ambulation. Results: Forty-two fetuses were included. Joint movement seen on US varied by POD: it was present on POD 1 in 7% of fetuses and 62% by POD 5. Degree of ventriculomegaly, lesion level, and lesion length did not have a significant effect on US, NE, or ambulation. Knee movement on POD 3 correlated with knee movement at NE (k = 0.58, p < 0.01), but only later knee movement correlated with ambulation (k = 0.28–0.46, p = 0.01). Hip movement at 32 weeks was the only single joint assessment that correlated with NE and ambulation (k = 0.45 and 0.46, p = 0.03 and 0.01, respectively). Conclusion: Lower extremity movement increases between POD 1 and POD 5 in fetuses after open fetal MMC repair. Knee and hip movement on US at 32 weeks correlates with ambulation at 30–36 months. These data may inform counseling, and direct therapy and spark prospective investigations.

Acquisition of normal contact stiffness and its influence on rock crack propagation for the combined finite-discrete element method (FDEM)

The combined finite-discrete element method (FDEM) has been widely used in numerical studies in the fields of rock mechanics and geotechnical engineering. The normal contact stiffness between triangular elements is an important influencing parameter, but there is currently no effective method of measuring it. First, an equation for normal contact stiffness is proposed (Pb = αPf, where Pb is the basic stiffness, α is the coefficient, and Pf is the joint penalty; the specific stiffness of each contact couple is determined by Pb and the geometric sizes of the triangular elements together); then, the compression-shear failure of a single joint element is used to study the value range and robustness of α; finally, uniaxial compression and tunnel excavation simulations are used to study the influence of different α values on rock crack propagation. The study results show that (1) an α value of 0.1448 is optimal and robust for a single joint element simulation and is therefore suitable for all simulation conditions; in other words, the value of α should not be too low to avoid decreasing the rock mass stiffness of existing natural fractures and deviating from the actual situation; in addition, the value of α should also not be too large to avoid the development of additional cracks, especially for hard rock simulation, in which the value of α is more sensitive; and (2) the crack topologies of the surrounding rock obtained by tunnel excavation simulation with a large α value deviate from the actual rock core (i.e., when α = 0.1448, the simulation results coincide well with the actual fractures). Through this study, the reliability of FDEM numerical simulation results is improved.