Joint Displacement Research Articles

Diagnostic efficacy of CBCT, MRI and CBCT-MRI fused images in determining anterior disc displacement and bone changes of temporomandibular joint.

To evaluate the diagnostic efficacy of CBCT-MRI fused image for anterior disc displacement and bone changes of temporomandibular joint (TMJ), which are the main imaging manifestations of temporomandibular disorders (TMD). Two hundred and thirty-one TMJs of 120 patients who were diagnosed with TMD were selected for the study. The anterior disc displacement, bone defect and bone hyperplasia evaluated by three experts were used as a reference standard. Three residents individually evaluated all the three sets of images, which were CBCT images, MRI images and CBCT-MRI fused images from individual CBCT and MRI images in a random order for the above-mentioned three imaging manifestations with a five-point scale. Each set of images was observed at least 1 week apart. A second evaluation was performed 4 weeks later. Intra- and interobserver agreements were assessed using the intraclass correlation coefficient (ICC). The areas under the ROC curves (AUCs) of the three image sets were compared with a Z test, and p < 0.05 was considered statistically significant. One hundred and forty-five cases were determined as anterior disc displacement, 84 cases as bone defect and 40 cases as bone hyperplasia. The intra- and interobserver agreements in the CBCT-MRI fused image set (0.76-0.91) were good to excellent, and the diagnostic accuracy for bone changes was significantly higher than that of MRI image set (p＜0.05). CBCT-MRI fused images can display the disc and surrounding bone structures simultaneously and significantly improve the observers' reliability and diagnostic accuracy, especially for inexperienced residents.

Salt spray aging effects on dynamic responses and failure characteristics of hybrid bonded-riveted CFRP/Al joints under high speed loading

Carbon fiber reinforced plastic (CFRP) composites exhibit great potential in connecting with metallic materials to fabricate desired structures with superior properties. Since composite/metal structures are expected to experience corrosion and impact loading during their long-term service, this paper comprehensively studied the effects of high speed loading and cyclic salt spray-dry-wet exposure on dynamic responses of hybrid bonded-riveted CFRP/Al joints. Experimental results indicated that the joint load-carrying capability was relatively higher with increased loading speed. The peak load, fail displacement and energy absorption of joints were sensitive to salt spray exposure and progressively declined with higher aging time. A high speed camera was implemented to record the whole failure process of hybrid joints under dynamic loading for further progressive failure analyses. The representative specimens were selected to comparatively investigate their failure characteristics and found that the failure process of samples under high speed loading (5–10 m/s) was considerably different with respect to aging time and loading speed.

Design and Analysis of the Spray-Painting Robot for tall statues and monuments

The painting on tall structures, statues, monuments and buildings is dangerous task for humans. Robotics finds its applications in operations, which are repetitive, hazardous, and dangerous. The aim of the present work is to design a manipulator for spray painting on surfaces of tall monuments, statues and structures. The robot can be installed on a crane platform for lifting and operated from the ground. A lightweight and compact design is desired that can be easily accommodated within the space of the crane. A Revolute-Revolute-Revolute-Prismatic (RRRP) type Robotic arm is developed and analysed for this application. By establishing the rigid body tree model in Robotics System Toolbox, the numerical model of direct and inverse kinematics using Homogenous Matrix Transformation is prepared in MATLAB. Using the spray patch method and offline programming method, the spray model is prepared in Solid woks to obtain trajectory waypoints. A B-spline path is generated through these waypoints. At each waypoint, joint displacement variables are calculated using an inverse kinematic model. An air-less spray gun is selected and attached with a robot. Controlled motion algorithm for spray painting operation on a circular surface were obtained with simulation results. A smooth trajectory for performing spray painting is obtained.

Development of an AFO with Dual-material using an FDM Printer

This paper presents a design and development of an Ankle Foot Orthosis (AFO) printed with a multi-extrusion Fused Deposition Modelling (FDM) printer. AFO is crucial in the healing of patients with ankle joint displacement. It helps to heal the foot easily. The model is designed to print with dual materials such as flex and polylactic acid (PLA). The critical problem in building a prototype is to obtain excellent bonding properties between the layers of different materials. The Flex material is softer than the PLA and both have different melting temperatures. Thus, successfully printing with an excellent adhesive is the key concern in multimaterial applications. The paper also presents the simulation results of an AFO to justify the mechanical properties and required materials for sustainable development.

Clinical Efficacy of Dexmedetomidine versus Ketamine in Shoulder Dislocation Reduction: A Randomized Clinical Trial Study.

Background :Shoulder joint dislocation and displacement is a common clinical condition. The present research aims to compare the clinical efficacy of ketamine versus dexmedetomidine during shoulder joint reduction. Methods : In this randomized clinical double-blind trial method, patients aged 18 to 65 years with shoulder dislocation referred to the Emergency Hospital of Imam Khomeini Hospital in Ahvaz, Iran, were enrolled. Patients were separated into two groups, patients in group A received 1mg/kg nebu-lized ketamine and patients in group B received 1 μg/kg nebulized dexmedetomidine. Pain score was recorded at 5 different time points: Zero (before intervention), 10 minutes, 20 minutes, 30 minutes, and 60 minutes after intervention., The pain score was evaluated using the visual analog scale (VAS) test. A linear regression test was carried out to compare the slopes. Also, ANOVA repeated measures test variables differences between groups. Then Tukey's multiple comparisons as post-hock were applied to compare the pains at different time points. Using IBM SPSS version 19.0 software, all analyzes were accomplished. Results : The pain score in both groups significantly decreased during different time points. The pain reduction slope in the group that received dexmedetomidine is meaningfully upper than that of ketamine (-0.08 vs. -0.06, p=0.012). The ketamine action onset time was 20 minutes after the in-tervention. In comparison, the effect of dexmedetomidine has an onset of 10 minutes after the in-tervention. Conclusion : Overall, the results of current research demonstrated that although nebulized dexme-detomidine and nebulized ketamine produce a significant decrease in pain score, dexmedetomidine provides a faster effect. Therefore, nebulized dexmedetomidine seems to be used as an appropriate choice to induce sedation during shoulder joint reduction in emergency departments.

Prediction model for maximum shear displacement of pipe joints with preexisting defects based on finite element–multiple nonlinear regression method

AbstractUnder the coupling effect of the defects inside and around pipes, the shear displacement of the joints of old concrete pipes fallen into disrepair usually shows an accelerated deterioration trend, and its excessive value can lead to structural damage or fluid leakage. Therefore, developing a prediction model for the maximum shear displacement of concrete drainage pipe joints with preexisting defects is of crucial significance. To this end, this work selects internal corrosion and erosion voids as the typical defects inside and around old pipes, establishes 300 sets of three‐dimensional fine finite element (FE) models of the concrete drainage pipes with corrosion and void, and verifies the reliability of the developed FE model by the full‐scale tests. Based on the verified FE data, a prediction model is successfully proposed for the assessment of the maximum shear displacement of the concrete drainage pipe joints with corrosion and void defects. Moreover, parameter sensitivity analysis is carried out to reveal their relative contribution to the maximum shear displacement of pipe joints. The results show that the model proposed herein has the ability to accurately predict the maximum shear displacement of the pipe joints. The maximum and minimum relative error between the value predicted by the proposed model and the one computed by the FE model is also 12.4% and 4.8% respectively. Moreover, the traffic load with a contribution of 28.7% has the greatest impact on the maximum shear displacement of pipe joints.

Real-time gait planning method for six-legged robots to optimize the performances of terrain adaptability and walking speed

The terrain adaptability and the walking speed are two key performances of legged robots. However, methods to optimize these performances are seldom developed, especially in real-time application. This paper proposes a novel gait planning method for six-legged robots to optimize both the terrain adaptability and the walking speed. First, a six-legged robot with parallel mechanisms and the typical tripod gait are introduced. Then, the optimization problem is addressed by minimizing the displacements of the active joints and solved by applying the pseudo-inverse. Further, the performance improvements are analyzed by comparing the optimized gait with the non-optimized gait. Finally, experiments are conducted on the prototype to validate the method. The results show that the maximum AoS (angle of the slope) and the maximum SHR (step to body height ratio) are improved by 48.8% and 96.0%, respectively. The maximum SLR (speed to body length ratio) is improved by 17.1%. More importantly, all essential calculations are fulfilled within 1ms, which proves the feasibility of the method in real-time control systems.

Creep behavior of human knee joint determined with high-speed biplanar video-radiography and finite element simulation

Creep and relaxation of knee cartilage and meniscus have been extensively studied at the tissue level with constitutive laws well established. At the joint level, however, both experimental and model studies have been focused on either elastic or kinematic responses of the knee, where the time-dependent response is typically neglected for simplicity. The objectives of this study were to quantify the in-vivo creep behavior of human knee joints produced by the cartilaginous tissues and to use the relevant data to validate a previously proposed poromechanical model.Two participants with no history of leg injury volunteered for 3T magnetic resonance imaging (MRI) of their unloaded right knees and for biplanar video-radiography (BVR) of the same knees during standing on an instrumented treadmill for 10 min. Approximately 550 temporal data points were obtained for the in-vivo displacement of the right femur relative to the tibia of the knee. Models of the bones and soft tissues were derived from the MRI. The bone models were used to reconstruct the 3D bone kinematics measured using BVR. Ground reaction forces were simultaneously recorded for the right leg, which were used as input for the subject-specific finite element knee models. Cartilaginous tissues were modeled as fluid-saturated fibril-reinforced materials.In-vivo creep of the knee was experimentally observed for both participants, i.e., the joint displacement increased with time while the reaction forces at the foot were approximately constant. The creep displacements obtained from the finite element models compared well with the experimental data when the tissue properties were calibrated (Pearson correlation coefficient = 0.99).The results showed the capacity of the poromechanical knee model to capture the creep response of the joint. The combined experimental and model study may be used to understand the fluid-pressure load support and contact mechanics of the joint using material properties calibrated from the displacement data, which enhance the fidelity of model results.

Effectiveness of occlusal splints with low-level laser therapy on anterior disc displacement of the temporomandibular joint

ABSTRACT Objective: This study was designed to evaluate and compare between the using of oral appliance therapy alone and using of oral appliance with laser therapy for management of anterior disc displacement of the temporomandibular joint. Subjects and methods: randomized clinical study was done on 18 patients complaining of TMJ Anterior disc displacement. They were divided into 2 equal groups. Group A:occlusal appliance group Those patients worn the hard acrylic occlusal appliance covering the maxillary teeth (anterior repositioning splint) at night for two months. Group B: laser therapy group Those patients worn the hard acrylic occlusal appliance covering the maxillary teeth (anterior repositioning splint) at night and receive laser applications on the region of temporalis muscle, masseter muscle and mandibular condyle three times a week for 4 weeks. full clinical TMJ examination was done at 0 baseline,one week, one month and two months postoperatively. The examination was done to evaluate T.M.J pain intensity by (VAS), TMJ clicking Sounds and Maximum mouth opening .Magnetic resonance imaging(MRI) performed before and after treatment period. Results There was high percentage of improvement in all symptoms of anterior disc displacement either with or without reduction by using of double action of splint and laser rather than the improvement by using splint only. Conclusion :The using of splint only is acceptable and successful but the using of the laser with splint is better and more successful in treatment of the patients complained from anterior disc displacement of the temporomandibular joint.

ПОВТОРНЕ ВИКОРИСТАННЯ МОСТОВИХ БАЛОК В ЯКОСТІ ПРОГОНОВИХ БУДОВ ТИМЧАСОВИХ МОСТІВ

Introduction. This article presents the results of study of the quality of girders that were used for the construction of temporary road bridge. In the bridge construction practice there is a need to use girders in the construction of road bridges on local roads that can be reused in temporary bridges construction. It is important when using such structures to determine their reliability for long-term operation. The cost of bridge girders is up to 60% of the cost of a new bridge, so the reuse of utilizedsed girders is economically feasible. Utilized girders can be reused on local roads and temporary bridges. Problem statement. To determine the usability of utilized girders in temporary bridges construction and provide recommendations for the girders reuse and possible bridge design structures. Materials and methods. The following works were performed during the inspection: visual inspection of the girders at places of their storage after dismounting; measurement of the basic sizes of girders; determination of concrete strength by non-destructive test method; determination of the number of working reinforcement and the protective layer thickness; measurements of pH of concrete of a protective layer were performed; registration of existing defects was performed. The following measurements were performed during the tests: general displacements and deformations of structural elements of the structures; relative deformations of cross sections; local deformations (displacements in joints). Results. According to the results of tests and calculations, the bearing capacity of the bridge span structure was determined. After analyzing the results of experimental and theoretical studies, conclusions were made regarding the operational performance of the girders of the bridge span structure. Conclusions. Girders in the 1st, the 2nd and the 3rd technical state can be considered suitable for bridge span structures unreservedly. Girders in the 4th technical state, need repairing and reinforcement for reuse in bridge span structures. They cannot be used without repairing. Girders in the 5th technical state cannot be used in the span structures of road bridges. They can be used, for example, as transition slabs, or for pedestrian bridges and crossings, or can be used for testing the technology of bridge structures repairing. Thus, tests of bridge girders and full-size joints testify that the accepted design decision provides the needed bearing capacity of girders and of the bridge span structure as a whole. This confirms the sufficient reliability of utilized girders in the further work. Practice shows that it is also needed to pay great attention to the following: firstly- to the methods of dismantling the girders without damage; secondly — to the proper storage of girders after dismantling.

Successful Treatment of Acute Craniodorsal Coxofemoral Luxation in a Scarlet Ibis (Eudocimus ruber) Using Closed Reduction and a Modified Ehmer Sling.

Whereas craniodorsal displacement of the coxofemoral joint is the most common luxation reported in small and large mammals, it occurs less often in avian species. Closed reduction and external coaptation with a modified Ehmer sling is the initial treatment, in most cases, for small animals (eg, dogs, cats) that present with a coxofemoral luxation. However, the Ehmer sling is reported to have a low success rate in treating coxofemoral luxations in these animals. Intractable coxofemoral luxations require an open surgical reduction. A few successful closed reductions of coxofemoral luxations have been reported in avian patients, as well as open reduction surgical techniques to repair avian coxofemoral luxations. The successful treatment of an acute craniodorsal coxofemoral luxation in a scarlet ibis (Eudocimus ruber) with a closed reduction and a modified Ehmer sling is described in this clinical report. The specific characteristics of both the patient and the injury are thought to have contributed to the success in this case.

Intraoperative arthrography monitoring assisted closed reduction and internal fixation for intercondylar fracture of humerus in children

To investigate clinical effects of intraoperative arthrography monitoring assisted closed reduction and internal fixation for intercondylar fracture of humerus in children. From January 2013 to July 2018, 18 children with intercondylar fracture of humerus were treated by operation, including 13 males and 5 females aged from 3 to 12 years old with an average age of (8.50±2.57) years old. According to Toniolo & Wilkinson classification, 8 children were typeⅠand 10 children were typeⅡ. During the operation, closed reduction and internal fixation were performed under the monitoring of intraoperative radiography, open reduction and internal fixation were performed in necessity. Mayo score of elbow joint was used to evaluate clinical effect at 6 months after operation. All children were underwent arthrography monitoring during operation, 5 children were treated with closed reduction and internal fixation for intraoperative arthrography found no fracture of articular cartilage, 11 children by closed reduction and internal fixation because of fracture of articular cartilage involving the joint space with displacement less than 2 mm, and 2 children by closed or open reduction and internal fixation for fracture of articular cartilage surface with displacement above 2 mm, which 1 child with smooth of joint surface was performed closed reduction and internal fixation, 1 child without smooth of joint surface and displacement above 2 mm was performed open reduction and internal fixation. All children were followed up from 8 to 26 months with an average of (20.28±4.40) months. All factures were healed from 6 to 9 weeks with an average of (7.33±0.77) weeks. Postoperative Mayo score of elbowjoint at 6 months was (89.44±11.36), and 12 patients got excellent results, 5 good and 1 poor. One patient occurred partial limitation of flexion or extension of elbow joint. No elbow deformity and other complications occurred. The treatment of intercondylar fracture of humerus in children under monitoring of intraoperative radiography could reduce opertaion injuries and complications, confirm the reduction effect of articular surface of cartilage in time and clearly, and promote recovery of elbow joint function.

Standing Long Jump Performance in Youth with Visual Impairments: A Multidimensional Examination

Muscular fitness, an important marker of health in youth, includes explosive strength, which can be assessed using the standing long jump (SLJ). Little is known concerning the SLJ in populations with disabilities such as youth with visual impairments (VI) who trend with decreased health- and performance-related outcomes. The purposes of this study were to investigate multidimensional SLJ performance outcomes in youth with VI (i.e., descriptives and percentages of occurrence) and to explore associations among such variables and known factors of interest (e.g., age) using robust linear bivariate regressions. This study was a secondary analysis from data collected in 2018 (N = 61, Mage = 12.98 years, SD = 2.21). SLJ performance was investigated using a multidimensional focus (e.g., distance, Test of Gross Motor Development-3 horizontal jump, landing developmental sequences, landing joint displacement, and stabilization after landing). In general, SLJ performance was substandard in youth with VI. Most SLJ assessment scores were predictive of other SLJ assessment scores. Few hypothesized variables of interest (e.g., multimorbidity) were predictive of SLJ performance. Youth with VI who match the characteristics of the current sample may have decreased explosive strength/muscular fitness and, worryingly, their SLJ performance may not be influenced by expected factors (e.g., age). Implications and explanations for these results are discussed.

Energy Distribution in Dowel-Type Joints in Timber Structures When Using Expansive Kits

This paper provides a study of the mechanical energy distribution in dowel-type joints in timber structures when using expansive kits. The compression caused by the expansive kit increases the friction between the dowel and the timber’s hole, opposing the longitudinal sliding that occurs during the bending of the dowel. The ensuing rope effect increases the load capacity of the joint. The aim was to determine the advantages and disadvantages of using this kind of reinforcement. For this purpose, an ad hoc finite element model of the joint was prepared taking the contact between the different components of the joint into account and appropriately simulating the radial expansion of the dowel and the behavior of the timber. The model was checked for accuracy by comparing the results with those coming from a set of experimental tests. After that, the model was used to verify that the use of the expansive kit reinforcement leads to a slight improvement in the load capacity of the joint. This improvement is related to the frictional forces, whose effect is especially significant at low levels of joint displacement.

Comparative Study Seismic Analysis of RCC, Steel &amp; Steel-Concrete Composite Frame: A Review

Abstract: This study examines how composite structures are gaining popularity in developing countries. For medium and high levels in RCC buildings are no longer economical due to increased weight, range limitations and low natural frequencies and dangerous formwork. Steel and concrete composite structures are becoming increasingly popular today and are safe throughout their useful lives. Round Steel and concrete structures are the best solution for modern buildings. In this article we will discuss the various results of building construction for RCC, metal and composite construction taking into account different studies. Keyword: RCC Structure, Steel Structure, Composite Structure, Joint Displacement, Base Shear

CIS-ATRACURIUM WITH MASSETER MUSCLE SPASM: AN UNANTICIPATED DIFFICULT ENDOTRACHEAL INTUBATION AND TEMPOROMANDIBULAR JOINT DISPLACEMENT: A CASE REPORT

Masseter muscle spasm and displacement of temporomandibular joint under anaesthesia could be life threatening if an anaesthesiologist is not prepared. We present a case of 23 years old young lady, who otherwise healthy, having symptoms of abdominal pain and vomiting. Initial baseline workup showed a solitary gallstone and was then planned for urgent laparoscopic cholecystectomy. The challenges faced in the perioperative period were the management of unanticipated masseter muscle spasm and difficult endotracheal intubation after administration of cisatracurium, and temporomandibular joint displacement.

Comparative analysis of three categories of four-DOFs exoskeleton mechanism based on relative movement offsets

PurposeThe purpose of this paper is to evaluate three categories of four-degrees of freedom (4-DOFs) upper limb rehabilitation exoskeleton mechanisms from the perspective of relative movement offsets between the upper limb and the exoskeleton, so as to provide reference for the selection of exoskeleton mechanism configurations.Design/methodology/approachAccording to the configuration synthesis and optimum principles of 4-DOFs upper limb exoskeleton mechanisms, three categories of exoskeletons compatible with upper limb were proposed. From the perspective of human exoskeleton closed chain, through reasonable decomposition and kinematic characteristics analysis of passive connective joints, the kinematic equations of three categories exoskeletons were established and inverse position solution method were addressed. Subsequently, three indexes, which can represent the relative movement offsets of human–exoskeleton were defined.FindingsBased on the presented position solution and evaluation indexes, the joint displacements and relative movement offsets of the three exoskeletons during eating movement were compared, on which the kinematic characteristics were investigated. The results indicated that the second category of exoskeleton was more suitable for upper limb rehabilitation than the other two categories.Originality/valueThis paper has a certain reference value for the selection of the 4-DOFs upper extremity rehabilitation exoskeleton mechanism configurations. The selected exoskeleton can ensure the safety and comfort of stroke patients with upper limb dyskinesia during rehabilitation training.

Tensile behavior of FRP bar butt joints built with new FRP sleeves

This paper reports a comprehensive investigation on the tensile behavior of FRP bar butt joints built with new FRP sleeves. The simplified bond-slip constitutive relationship between FRP bars and bonding medium was firstly established by using the existing research results. Based on five proposed assumptions, the stress–strain analysis of the FRP bar butt joint was performed on the FRP bar, bonding medium and sleeve under tensile load. The bond-slip behavior and the shear force between FRP bars and bonding medium were discussed in detail. According to the stress–strain analysis, the key design parameters of the FRP sleeve and the anchor length of FRP bars were determined, which is also verified by comparing test data. According to the design parameter and anchor length, two types of FRP sleeves with two different internal structures and lengths were designed, and then these FRP sleeves were made of GFRP by professional manufacturers. In addition, the axial tensile tests were conducted on a total of 10 BFRP bar butt joints, GFRP bar butt joints and CFRP bar butt joints which are connected by the proposed GFRP sleeves. Based on the test results, the failure modes of various FRP bar butt joints built with GFRP sleeves were observed, and the corresponding tensile load–displacement curves, maximum tensile load and strain were analyzed. Finally, it is found that all fractures occur on the connected FRP bars instead of the GFRP sleeves, which indicates that various FRP bars can be effectively connected by the two types of GFRP sleeves. The load–displacement curves of the GFRP sleeves exhibit a small linear elastic deformation before the FRP bars rupture. The maximum elongated length of the GFRP sleeves is only 13% of the maximum tensile displacement of FRP bar butt joints uner tensile load, while the maximum circumferential strain of GFRP sleeves is about 41.72% of their corresponding longitudinal strain.

Analysis of the correlation between chewing side preference and disc displacement types and clinical symptoms in patients with anterior disc displacement of temporomandibular joint

Objective: To analyze the clinical symptoms and types of disc displacement of patients with anterior disc displacement (ADD) of temporomandibular joint (TMJ) and to explore the correlation between chewing side preference (CSP) and the clinical symptoms and types of disc displacement of ADD patients. Methods: This was a cross-sectional study of the ADD patients diagnosed by clinical symptoms and MRI findings of TMJ in the Department of Stomatology, General Hospital of Chinese PLA from January 2018 to December 2019. A total of 111 ADD patients [33 males and 78 females, aged(31.0±10.9) years old] were included. The patients were divided into two groups according to whether they had CSP: non-CSP group (n=40) and CSP group (n=71). The clinical symptoms and types of ADD were observed and recorded. According to the specific side of CSP in the CSP group, the patients were further divided into the ipsilateral side and the contralateral side of CSP. The pain, TMJ sounds and the ADD types were also observed. Chi square test was used to compare the pain, TMJ sounds, limited mouth opening and ADD types of the two groups. Binary Logistic regression model was used to analyze the correlation between CSP and clinical symptoms and ADD characteristics. Results: The incidence of pain in the CSP group [89% (63/71)] was significantly higher than that in the non-CSP group [70% (28/40)] (P<0.05). In CSP patients, the incidences of pain and joint sounds on the ipsilateral side of CSP were significantly higher than that on the contralateral side (P<0.05). MRI showed that the incidence of bilateral ADD in the CSP group [58%(41/71)] was significantly higher than that in the non-CSP group [37%(15/40)] (P<0.05).There were significant differences in the incidences of no disc displacement (DD), anterior disk displacement with reduction(ADDwR) and anterior disk displacement without reduction (ADDwoR) between ipsilateral and contralateral joints of the CSP patients (P<0.05). There were no significant differences in the incidences of no DD, ADDwR and ADDwoR between left and right joints of the non-CSP patients (P>0.05). The incidence of ADDwoR in ipsilateral side of the CSP patients was significantly higher than that in contralateral side (P<0.05). Pain (OR=3.375) and the side of disc displacement (OR=2.278) in patients with ADD were positively correlated with CSP (P<0.05). Conclusions: The clinical symptoms and types of disc displacement between patients with and without CSP were significantly different. The incidences of pain and bilateral disc displacement in the CSP group were significantly higher than those in the non-CSP group. In addition, the incidences of pain, TMJ sounds and anterior disk displacement without reduction on the ipsilateral side of patients with CSP were significantly higher than those on the contralateral side. The pain symptoms and side of disc displacement were positively related to CSP.

Restrictions in Ankle Dorsiflexion Range of Motion Alter Landing Kinematics But Not Movement Strategy When Fatigued.

Ankle dorsiflexion range of motion (DF ROM) has been associated with a number of kinematic and kinetic variables associated with landing performance that increase injury risk. However, whether exercise-induced fatigue exacerbates compensatory strategies has not yet been established. (1) Explore differences in landing performance between individuals with restricted and normal ankle DF ROM and (2)identify the effect of fatigue on compensations in landing strategies for individuals with restricted and normal ankle DF ROM. Cross-sectional. University research laboratory. Twelve recreational athletes with restricted ankle DF ROM (restricted group) and 12 recreational athletes with normal ankle DF ROM (normal group). The participants performed 5 bilateral drop-landings, before and following a fatiguing protocol. Normalized peak vertical ground reaction force, time to peak vertical ground reaction force, and loading rate were calculated, alongside sagittal plane initial contact angles, peak angles, and joint displacement for the ankle, knee, and hip. Frontal plane projection angles were also calculated. At the baseline, the restricted group landed with significantly less knee flexion (P = .005, effect size [ES] = 1.27) at initial contact and reduced peak ankle dorsiflexion (P < .001, ES = 1.67), knee flexion (P < .001, ES = 2.18), and hip-flexion (P = .033, ES = 0.93) angles. Sagittal plane joint displacement was also significantly less for the restricted group for the ankle (P < .001, ES = 1.78), knee (P < .001, ES = 1.78), and hip (P = .028, ES = 0.96) joints. These findings suggest that individuals with restricted ankle DF ROM should adopt different landing strategies than those with normal ankle DF ROM. This is exacerbated when fatigued, although the functional consequences of fatigue on landing mechanics in individuals with ankle DF ROM restriction are unclear.