Joint Position Research Articles

The effects of neuro-vestibular-ocular exercises and myofascial release on proprioception and performance in football players with chronic ankle instability

BACKGROUND AND PURPOSE: Football players often use quick change of direction, sudden acceleration and explosive movements. This is why chronic ankle instability is one of the most common conditions affecting this athlete population. This study investigates the effects of neuro-vestibular-ocular exercises and myofascial release on proprioception and performance in football players with chronic ankle instability. MATERIALS AND METHODS: This randomized controlled clinical trial included 60 football players aged 18–30. The players were randomly divided into two groups. The first group (NVOEG, n=30) was included in the Neuro-Vestibular-ocular exercise training program, while the myofascial release was applied to the second group (MRHOG, n=30). Both protocols were applied for eight weeks. The participants’ Cumberland Ankle Instability Tool (CAIT) scores were assessed before and after the intervention. Proprioception was evaluated by using the joint position sense test. Additionally, kick speed (KS), 30-m sprint, zig-zag agility test (ZAT) and Landing error score system (LESS) tests were applied to evaluate their performance. RESULTS: Post-rehabilitation scores showed significant differences in proprioception and performance parameters compared to pre-scores in both groups. (p<0.05). Significant differences were observed between the NVOEG and MRHOG in the post-test scores, including CAIT for unstable and stable ankle, proprioception for unstable ankle, LESS, ZAT with ball performance, and 30-meter sprint test. CONCLUSIONS: The neuro-vulvular-ocular exercise training protocol had superior results in terms of proprioception and performance parameters in chronic ankle instability management for football players.

Influencing Factors for Joint Awareness After Total Hip Arthroplasty: A Cross-Sectional Study

Objective: Total hip arthroplasty (THA) is a common procedure nowadays, with hospitals easily reaching hundreds of surgeries a year and considering the cross-sectional nature. Joint awareness (JA) is indicative of the patient's adaptation and satisfaction after THA. The current study investigated the relationship between joint awareness, joint position sense (JPS), mobility level, activities of daily living, and hip pain level in patients with THA.
 Methods: This is a cross-sectional study involving 50 individuals with THA (31.48±55.14 weeks post-surgery; mean age was 54.32±18.28 years). Factors related to joint awareness were examined with linear regression analysis. Hip Joint position sense (JPS) was measured with a digital inclinometer, pain level was measured with a Visual Analog Scale (VAS), joint awareness was assessed with the Forgotten Joint Score-12, and mobility level was assessed with the Parker Mobility Index.
 Results: The factors that have a statistically significant effect on the joint awareness are age, pain, mobility, and BMI (p = 0.002, p = 0.040, p

Plantar load distribution with centers of gravity balance and rearfoot posture in daily lives of Taiwanese college elite table tennis players: a cross-sectional study.

Table tennis is an asymmetric sport involving the powerful forward swing of the upper limbs depends on the solid support of the lower limbs. The foot drive really affects the weight balance and stroke accuracy even though the distance and momentum of the lower limb displacement are limited within a limited range. Given that previous research on table tennis has typically focused on the footwork and stroke performance of professional players, the study aimed to investigate the daily static and dynamic plantar load distribution as well as the centers of gravity balance and rearfoot posture among Taiwanese college elite table tennis players. This is a cross-sectional study of 70 elite male table tennis players (age: 20.0 ± 0.9 years; height: 173.4 ± 5.1 cm, weight: 67.6 ± 5.3 kg, experience: 10.0 ± 1.6 years) and 77 amateur table tennis players of the same gender (age: 20.1 ± 0.8 years, height: 167.4 ± 4.4 cm, weight: 64.3 ± 4.0 kg, experience: 4.4 ± 1.2 years) from Taiwanese universities. The JC Mat optical plantar pressure analyzer was applied to determine the plantar load distribution along with arch index (AI) and centers of gravity balance. Assessment of rearfoot postural alignment was mainly used to contrast the performance of the centers of gravity balance. The static arch indices of both feet in the elite group were symmetrical and considered normal arches (AI: 0.22 ± 0.07) during their non-training and non-competition daily lives. Their static plantar loads were symmetrically concentrated on the bipedal lateral metatarsals (P < 0.05) as well as shifted to the medial and lateral heels (P < 0.05) and the lateral metatarsals (P < 0.05) during the walking midstance phase. Additionally, the plantar loads were mainly applied to the bipedal medial (P < 0.01) and lateral heels (P < 0.05) during the transitional changes between both states. Elite athletes had symmetrical and evenly distributed centers of gravity on both feet (left: 50.03 ± 4.47%; right: 49.97 ± 4.47%) when standing statically, along with symmetrical rearfoot angles and neutral position of the subtalar joint (left: 2.73 ± 2.30°; right: 2.70 ± 2.32°) even though they were statistically lower than those of the amateur athletes (P < 0.05). The daily static and dynamic foot patterns of Taiwanese college elite table tennis players were characterized by plantar load distribution on the lateral metatarsals and the entire calcaneus along with balanced centers of gravity and normal rearfoot posture. This foot and posture layout outlines the excellent athletic performance of the foot and ankle in professional athletes. Portions of this text were previously published as part of a preprint (https://doi.org/10.21203/rs.3.rs-2993403/v1).

Effects of Eccentric Versus Concentric Strengthening in Patients With Subacromial Pain Syndrome: A Randomized Controlled Trial.

Subacromial pain syndrome (SPS) is the most common cause of shoulder pain. Therapeutic exercise is the first-line treatment for SPS; however, the ideal exercise type remains unclear. Here, we compared the effects of eccentric and concentric strengthening in patients with SPS. Adding isolated eccentric strengthening to a multimodal physiotherapy program (MPP) would lead to greater improvements in outcomes compared with either MPP alone or adding isolated concentric strengthening to the MPP. Randomized controlled trial. Level 2. A total of 45 patients were randomized to eccentric strengthening (ESG), concentric strengthening (CSG), and control (CG) groups; all groups received the MPP. The strengthening groups also performed group-specific strengthening. Shoulder pain, abduction and external rotation (ER) strength, joint position sense (JPS), the Constant-Murley Score (CMS), and the Disabilities of the Arm, Shoulder and Hand score were collected at baseline, after 12 weeks of treatment, and at week 24. For CMS, ESG exhibited a greater, but not clinically meaningful, improvement than CSG and CG (P < 0.05). Eccentric abduction strength increased in ESG compared with CG. From baseline to follow-up, abduction strength increased in ESG compared with CSG and CG. Eccentric abduction strength increased in CSG compared with CG. JPS at abduction improved in the ESG compared with CG. Other between-group comparisons were not significant (P > 0.05). In SPS, eccentric strengthening provided added benefits, improving shoulder abduction strength and JPS at abduction, and was superior to concentric strengthening for improving shoulder abduction strength. Neither strengthening approach had an additional effect on shoulder function, pain, ER strength, or rotational JPS. Clinicians could implement eccentric strengthening as a motor control retraining for strength and proprioception gain rather than for pain relief and reducing disability.

Postural control and ankle joint functions: an investigation on collegiate female volleyball players

PurposeAnkle injuries are common in volleyball players and are linked to the athlete’s postural control. The aim of the report is to investigate the differences between ankle functions and postural control ability of volleyball players and controls, and also the relationship between the variables in order to understand the factors affecting postural control.Methods40 female participants (age: 21.18 ± 0.27, volleyball players/controls: 20/20) were included in the study. Ankle functions (joint range of motion (ROM), joint position sense (JPS), vibration and isometric muscle strength) and postural control variables (anterior-posterior and medial-lateral sway velocity, ellipse area and perimeter) were evaluated by static stability test. The differences between the groups and the correlation between variables were analysed.ResultsSignificant differences favoured the volleyball group in ankle dorsiflexion, inversion, and eversion ROM, JPS, dorsiflexor and plantar flexor isometric muscle strength, and postural control variables (p &lt; 0.05). However, the control group demonstrated superior vibration sensitivity on the 1st and 5th metatarsal heads (p &lt; 0.05). A significant correlation was observed between the anterior-posterior sway velocity and dorsiflexion ROM, medial-lateral sway velocity and sway area with inversion ROM, sway area and vibration threshold in the 1st and 5th metatarsal heads (p &lt; 0.05).ConclusionsVolleyball players showed better results in ankle ROM, JPS, muscle strength and postural control. In addition to the similarities in ankle plantar flexion ROM, invertor and evertor isometric muscle strength between the groups, the controls showed better vibration sensitivity; which reveals potential causes of ankle injuries in volleyball players. Ankle function variables are found to be linked to postural control, highlighting the need to evaluate these functions for injury prevention.

Deep Semantic Graph Transformer for Multi-View 3D Human Pose Estimation

Most Graph Convolutional Networks based 3D human pose estimation (HPE) methods were involved in single-view 3D HPE and utilized certain spatial graphs, existing key problems such as depth ambiguity, insufficient feature representation, or limited receptive fields. To address these issues, we propose a multi-view 3D HPE framework based on deep semantic graph transformer, which adaptively learns and fuses multi-view significant semantic features of human nodes to improve 3D HPE performance. First, we propose a deep semantic graph transformer encoder to enrich spatial feature information. It deeply mines the position, spatial structure, and skeletal edge knowledge of joints and dynamically learns their correlations. Then, we build a progressive multi-view spatial-temporal feature fusion framework to mitigate joint depth uncertainty. To enhance the pose spatial representation, deep spatial semantic feature are interacted and fused across different viewpoints during monocular feature extraction. Furthermore, long-time relevant temporal dependencies are modeled and spatial-temporal information from all viewpoints is fused to intermediately supervise the depth. Extensive experiments on three 3D HPE benchmarks show that our method achieves state-of-the-art results. It can effectively enhance pose features, mitigate depth ambiguity in single-view 3D HPE, and improve 3D HPE performance without providing camera parameters. Codes and models are available at https://github.com/z0911k/SGraFormer.

Effect of pain on cranio-cervico-mandibular function and postural stability in people with temporomandibular joint disorders.

Neck and jaw pain is common and is associated with jaw functional limitations, postural stability, muscular endurance, and proprioception. This study aimed to investigate the effect of jaw and neck pain on craniocervico- mandibular functions and postural stability in patients with temporomandibular joint disorders (TMJDs). Fifty-two patients with TMJDs were included and assessed using Fonseca's Questionnaire and the Helkimo Clinical Dysfunction Index. An isometric strength test was performed for the TMJ depressor and cervical muscles. The TMJ position sense (TMJPS) test and cervical joint position error test (CJPET) were employed for proprioception. Total sway degree was obtained for the assessment of postural stability. Deep neck flexor endurance (DNFE) was assessed using the craniocervical flexion test. The mandibular function impairment questionnaire (MFIQ) was employed to assess mandibular function, and the craniovertebral angle (CVA) was measured for forward head posture. Jaw and neck pain negatively affected CVA (R2 = 0.130), TMJPS (R2 = 0.286), DNFE (R2 = 0.355), TMJ depressor (R2 = 0.145), cervical flexor (R2 = 0.144), and extensor (R2 = 0.148) muscle strength. Jaw and neck pain also positively affected CJPET for flexion (R2 = 0.116) and extension (R2 = 0.146), as well as total sway degree (R2 = 0.128) and MFIQ (R2 = 0.230). Patients with painful TMJDs, could have impaired muscle strength and proprioception of the TMJ and cervical region. The jaw and neck pain could also affect postural stability, and the endurance of deep neck flexors as well as mandibular functions in TMJDs.

The short- and long-term effects of congenital occlusion loss of the unilateral first permanent molar on the temporomandibular joint morphology and position: A retrospective study based on cone-beam computed tomography.

To investigate the effects of congenital unilateral first permanent molar occlusal loss (CUMOL) on the morphology and position of temporomandibular joint (TMJ). Cone-beam computed tomography (CBCT) images of 37 patients with CUMOL (18 males and 19 females, mean age: 13.60 ± 4.38 years) were divided into two subgroups according to the status of second molar (G1: the second molar not erupted, n = 18, G2: second molar erupted, n = 19). The control group consisted of 33 normal occlusion patients (9 males and 24 females, mean age: 16.15 ± 5.44 years) and was divided into 2 subgroups accordingly (G3: the second molar had not erupted, n = 18, G4: the second molar had erupted and made contact with the opposing tooth, n = 15). Linear and angular measurements were used to determine the characteristics of TMJ. In G1, the condyle on the side of the CUMOL shifts posteriorly, with significant side differences observed in Anterior space (AS, P < .05) and Posterior space (PS, P < .05). However, with the eruption of the second permanent molars, in G2, the condyle on the CUMOL side moves posteriorly and inferiorly. This results in significant lateral differences in the AS (P < .05), PS (P < .05), and Superior space (SS, P < .05). Additionally, there is an increase in the thickness of the roof of the glenoid fossa (TRF) on the CUMOL side (P < .05), and a decrease in the inclination of the bilateral articular eminences (P < .05). CUMOL can affect the position and the morphology of the condyle and was associated with the eruption of the second permanent molars. Before the eruption of the second permanent molars, CUMOL primarily affects the position of the condyle. After the emergence of the second permanent molars, CUMOL leads to changes in both the condyle's position and the morphology of the glenoid fossa.

Effects of Fibular Plate Fixation on Ankle Stability in a Weber B Fracture Model With Partial Deltoid Ligament Sectioning.

Weber B fractures with concomitant deltoid ligament injury have traditionally been operated with open reduction and internal fixation of the fibular fracture. More recently, clinical studies have suggested that some fractures have concomitant partial deltoid ligament injury with the deep posterior tibiotalar ligament intact (SER4a), allowing for nonoperative treatment in this subgroup. This study explores whether plate fixation of the fibula improves ankle stability in an SER4a injury model. And if so, does it restore native ankle stability? Fifteen cadaver ankle specimens were tested in 3 states using an industrial robot: intact joint, SER4a models without plate fixation of the fibula, and SER4a models with plate fixation of the fibula. The robot measured ankle stability in lateral translation, valgus, and internal and external rotation in 3 talocrural joint positions: 10 degrees dorsiflexion, neutral, and 20 degrees plantar flexion. Furthermore, fluoroscopic mortise view radiographs were taken to measure isolated talar shift and talar tilt. The talar shift and tilt tests showed no differences between the SER4a injury model with and without fibular plate fixation at neutral ankle position with a mean difference of -0.16 mm (95% CI -0.33 to 0.01 mm, P = .071) for talar shift and -0.15 degrees (95% CI -0.01 to 0.30 degrees, P = .068) for talar tilt. However, plate fixation increased external rotation stability, with mean improvements ranging from -7.43 to -9.52 degrees (P < .001 for all comparisons), but did not restore intact ankle stability. For internal rotation, plate fixation resulted in minor differences. The results of this suggest that plate fixation of the fibular fracture primarily improves external rotation stability but does not substantially improve lateral translation, valgus, or internal rotation stability in SER4a injury models. In this robotic cadaver model, fibular plate fixation did not fully restore intact ankle stability after simulated SER4a injury. This study offers insights into the effects of fibular plate fixation on Weber B/SER4a injury models and may assist informed decisions when selecting treatments for these types of fractures.

Fast Human Motion reconstruction from sparse inertial measurement units considering the human shape

Inertial Measurement Unit-based methods have great potential in capturing motion in large-scale and complex environments with many people. Sparse Inertial Measurement Unit-based methods have more research value due to their simplicity and flexibility. However, improving the computational efficiency and reducing latency in such methods are challenging. In this paper, we propose Fast Inertial Poser, which is a full body motion estimation deep neural network based on 6 inertial measurement units considering body parameters. We design a network architecture based on recurrent neural networks according to the kinematics tree. This method introduces human body shape information by the causality of observations and eliminates the dependence on future frames. During the estimation of joint positions, the upper body and lower body are estimated using separate network modules independently. Then the joint rotation is obtained through a well-designed single-frame kinematics inverse solver. Experiments show that the method can greatly improve the inference speed and reduce the latency while ensuring the reconstruction accuracy compared with previous methods. Fast Inertial Poser runs at 65 fps with 15 ms latency on an embedded computer, demonstrating the efficiency of the model.

Sensorless force estimation of teleoperation system based on multilayer depth Extreme Learning Machine

The force feedback technology has a crucial impact on the precise control of teleoperation system. Robots in fields such as minimally invasive surgery and nuclear waste cannot integrate force sensors to obtain force feedback due to their end size and harsh working environment. In order to obtain end-effector force feedback in sensorless situation, a sensorless force estimation model based on artificial neural network is defined in this paper. For improving the model prediction ability, a new Multi-layer Depth Extreme Learning Machine (MDELM) is proposed. Firstly, the network structure of the extreme learning machine is redesigned, and the smoothing function and Gauss-Laplacian function are constructed as the feature extraction layer and enhancement layer of the MDELM model. Then, to further improve the prediction performance of MDELM, an improved Sooty Tern Optimization Algorithm (STOA) is introduced to optimize the parameters of the model. The results show that the proposed force estimator outperforms the existing model with an MAE of less than 0.205, which is at least 18.65% lower than the existing model. In addition, when the acceleration of the remote operating system is a fixed constant or the information is not available，a sensorless force feedback system can be constructed by combining motor torque, joint position and joint velocity parameter. In general, this study provides an effective force estimation solution for teleoperation system without force sensor.

Comparing Video Analysis to Computerized Detection of Limb Position for the Diagnosis of Movement Control during Back Squat Exercise with Overload.

Incorrect limb position while lifting heavy weights might compromise athlete success during weightlifting performance, similar to the way that it increases the risk of muscle injuries during resistance exercises, regardless of the individual's level of experience. However, practitioners might not have the necessary background knowledge for self-supervision of limb position and adjustment of the lifting position when improper movement occurs. Therefore, the computerized analysis of movement patterns might assist people in detecting changes in limb position during exercises with different loads or enhance the analysis of an observer with expertise in weightlifting exercises. In this study, hidden Markov models (HMMs) were employed to automate the detection of joint position and barbell trajectory during back squat exercises. Ten volunteers performed three lift movements each with a 0, 50, and 75% load based on body weight. A smartphone was used to record the movements in the sagittal plane, providing information for the analysis of variance and identifying significant position changes by video analysis (p < 0.05). Data from individuals performing the same movements with no added weight load were used to train the HMMs to identify changes in the pattern. A comparison of HMMs and human experts revealed between 40% and 90% agreement, indicating the reliability of HMMs for identifying changes in the control of movements with added weight load. In addition, the results highlighted that HMMs can detect changes imperceptible to the human visual analysis.

Joint position sense error in the hip and knee without reference to the joint angle

BACKGROUND: Joint position reproduction measures the angle acuity of reference angle reproduction using an indicator angle. However, reference angles are often not available. OBJECTIVE: This study aimed to examine joint position sense at three different targeted joint angles, which were estimated from the maximum range of motion (maxROM) without a reference angle at each targeted joint angle. METHODS: The maxROM was measured in straight leg raise (SLR) and active knee extension (AKE) positions. In both positions, a targeted joint angle at 75% of the maxROM was assessed first, followed by that at 50% and 25% of the maxROM. A one-sample t-test was used to analyze differences between the targeted and reproduced angles in both positions. RESULTS: All reproduced angles significantly differed from the targeted angle in both SLR and AKE positions except for the reproduced angle measured at 75% maxROM. Overall, position errors in the AKE position were higher than those in the SLR position. CONCLUSIONS: Estimating the angle based on the maxROM without a matched reference angle may lead to significant discrepancies in comparison with the targeted joint angle. In clinical settings, if accurate reproduction of motions is required to improve proprioception, providing a reference angle might be helpful.

Efficacy of Isometric Exercises and Somatosensory Training for Pain, Proprioception, and Balance in Runners with Patellofemoral Pain Syndrome.

Background A significant cause of knee pain is patellofemoral pain syndrome (PFPS). Young adults are the most common population to be impacted, and this condition appears to affect both sexes. Patellofemoral joint (PFJ) compression, which is felt around the patella during any physical or athletic activity, usually causes patients to experience pain in the anterior part of the knee. Physiotherapy is essential for patients suffering from this illness, as it can improve their everyday activities and ability to return to their sport. Methodology The study's main goal was to evaluate the effectiveness of somatosensory training and isometric exercises for pain, proprioception, and balance in runners with PFPS. Before- and after-test approaches were used in the investigation. Eighty-five people made up the study, with the inclusion and exclusion criteria used to determine eligibility. Isometric exercises and somatosensory training were given to every individual; the group was not randomly assigned. The patient's diagnosis was made using the patellar grind test. Participants received 30-45 minutes of isometric exercises and 15 minutes of somatosensory training every four days. The visual analog scale, joint position sense test, and Y-balance test were taken as outcome measures to measure PFPS before and after the intervention. Results The result revealed significant (p=0.0001) improvement in PFPS following the intervention. Both the isometric exercises and somatosensory training were found to be significant in reducing the intensity of the pain and improving the proprioception and balance of the individuals. Conclusion Both treatment approaches were beneficial in lowering pain in the joints, developing balance, and helping the patient perceive the position of the joint. Individuals can use both therapy methods to improve their running abilities, and they should become ingrained in daily practice.

Acute effects of Nordic hamstring exercise on hip and knee joints proprioception

Background and objectivesNordic Hamstring Exercise (NHE) is one of the best exercises proposed for injury prevention of hamstring muscles. However, its effects on lower extremity proprioception are unclear. The aim of this study was to investigate the immediate effects of a single bout of NHE on hip and knee joints’ proprioception. MethodsForty collegiate male soccer players participated in this study with a mean age of 22.85 ± 1.82 years and were randomized into either control (n = 20) or experimental (n = 20) groups. Each subject participated in pre-test measurements in which hip and knee active joints position sense (JPS) were assessed in standing and lying tasks using the image-capturing method. The experimental group then performed three sets of NHE with 10 repetitions in each set, while the control group rested for 10 min. Paired and independent t-tests were used for calculating the differences within and between groups on SPSS software, respectively. The level of significance was P ≤ 0.05. ResultsHip JPS in the lying task and knee JPS in both of the standing and lying tasks were impaired significantly after performing a single bout of NHE (P ≤ 0.05). However, the effects of this exercise on hip JPS in the standing task were not significant (P ≥ 0.05). ConclusionsNHE performing with three sets of 10 repetitions can significantly impair hip and knee JPS immediately after exercise and reduce the proprioception acuity of the lower limbs. It is recommended to perform this exercise at a time rather than before training or match sessions.

GNSS/5G Joint Position Based on Weighted Robust Iterative Kalman Filter

The Global Navigation Satellite System (GNSS) is widely used for its high accuracy, wide coverage, and strong real-time performance. However, limited by the navigation signal mechanism, satellite signals in urban canyons, bridges, tunnels, and other environments are seriously affected by non-line-of-sight and multipath effects, which greatly reduce positioning accuracy and positioning continuity. In order to meet the positioning requirements of human and vehicle navigation in complex environments, it was necessary to carry out this research on the integration of multiple signal sources. The Fifth Generation (5G) signal possesses key attributes, such as low latency, high bandwidth, and substantial capacity. Simultaneously, 5G Base Stations (BSs), serving as a fundamental mobile communication infrastructure, extend their coverage into areas traditionally challenging for GNSS technology, including indoor environments, tunnels, and urban canyons. Based on the actual needs, this paper proposes a system algorithm based on 5G and GNSS joint positioning, aiming at the situation that the User Equipment (UE) only establishes the connection with the 5G base station with the strongest signal. Considering the inherent nonlinear problem of user position and angle measurements in 5G observation, an angle cosine solution is proposed. Furthermore, enhancements to the Sage–Husa Adaptive Kalman Filter (SHAKF) algorithm are introduced to tackle issues related to observation weight distribution and adaptive updates of observation noise in multi-system joint positioning, particularly when there is a lack of prior information. This paper also introduces dual gross error detection adaptive correction of the forgetting factor based on innovation in the iterative Kalman filter to enhance accuracy and robustness. Finally, a series of simulation experiments and semi-physical experiments were conducted. The numerical results show that compared with the traditional method, the angle cosine method reduces the average number of iterations from 9.17 to 3 with higher accuracy, which greatly improves the efficiency of the algorithm. Meanwhile, compared with the standard Extended Kalman Filter (EKF), the proposed algorithm improved 48.66%, 35.17%, and 38.23% at 1σ/2σ/3σ, respectively.

Sensory function and somatosensorial system changes according to visual acuity and throwing techniques in goalball players: A cross-sectional study.

The somatosensory system is a complect sensory system that differentiates individual athletes. The aim of this study is to investigate the effect of visual acuity level on throwing technique, proprioceptive sense of the shoulder joint, light touch and two-point discrimination sense of the upper extremity, and sensory function (postural control and reaction time) in visually impaired goalball players. Goalball players who have different visual acuities B1(unable to perceive light or recognize its shape); B2 (has a visual field of less than 5 degrees and can recognize shapes); B3 (visual field greater than 5 degrees and less than 20 degrees) participated in the study. The sensorial system was evaluated with proprioceptive sense of the shoulder joint and sensory tests (light touch and two-point discrimination sense of the dominant hand.). Sensory function (postural control and reaction time) was evaluated with the flamingo balance test, functional reach test, and pro-agility test. The goalball players' throwing technique was questioned. Seventeen male players, those aged 20-30 (20.8±3.9 years) who have been professionally engaged in goalball for at least three years (58.7-37.8 months) participated. Shoulder internal rotation joint position sense and the flamingo balance test were found to be different in the group with B1 visual acuity than in the group with B3 visual acuity (p = 0.042* and 0.028 respectively). There was no difference between groups with B1-B2 visual acuity (p = 0.394 and p = 0.065) and between groups with B2-B3 visual acuity (p = 0.792 and p = 0.931). There was no difference in the groups in terms of sensory tests and reaction time (p> 0.05). In goalball, joint position sense is related to throwing techniques. Although there is a general acceptance that other sensory systems should work harder to compensate for the sense of vision, fear of falling, athlete's branch year, sports year, muscle strength, and general physical condition of the athlete may affect the measurements made, especially in the dynamic position.

Temporomandibular joint disc position and shape in patients submitted to two protocols of rapid maxillary expansion and face mask therapy: A randomized clinical trial.

The objective of this prospective study was to assess possible changes in the position and shape of the temporomandibular joint (TMJ) articular disc in patients treated with two protocols of rapid maxillary expansion (RME) and face mask (FM) therapy. A sample of 88 patients with Class III or Class III subdivision malocclusions, aged between 6 and 13 years, were consecutively selected and divided into three groups (G): G1-34 patients were treated with RME, followed by FM therapy; G2-34 patients were treated using RME according to modified alternate rapid maxillary expansion and constriction (ALT-RAMEC) protocol, followed by FM therapy. These treated groups were randomly (1:1 allocation ratio) distributed according to the two treatment protocols. G3 - Control Group - 20 untreated patients were followed. Magnetic resonance imaging (MRI) TMJs were obtained before (T1) and after (T2) a treatment period or follow-up. McNemar test, Fisher's exact test and intra- and inter-observer concordance (K) were performed (p ≤ .05). There were no statistically significant differences in the baseline cephalometric variables at T1 between the groups. There were statistically significant differences between the groups (p < .001) in relation to the disc shape in T1, since G1 (8 TMJs -11.76%) presented higher occurrences of altered forms in comparison with G2 (no changes). No significant differences were observed in disc position CM and OM (G1 - p > .999; G2 - p = .063; G3 - p = .500) and shape (G1 - p > 0.999; G2 - p = .250; G3 - not calculable), between T1 × T2, in any of the groups studied. The two treatment protocols did not have adverse effects on the position and shape of the TMJ disc, in a short-term evaluation.

Comparing shoulder proprioception, upper extremity dynamic stability, and hand grip strength in overhead athletes with and without scapular dyskinesis

IntroductionScapular dyskinesis is prevalent among asymptomatic athletes, particularly those involved in overhead activities, and can significantly impact their neuromuscular control. These changes may impair upper extremity function and strength, elevating the risk of injury. Therefore, it is imperative to investigate how scapular dyskinesis affects shoulder proprioception, upper extremity dynamic stability, and hand grip strength in overhead athletes. This study compared these parameters between overhead athletes with and without scapular dyskinesis. MethodsThe study included twenty asymptomatic professional overhead athletes with scapular dyskinesis and twenty without scapular dyskinesis, identified using the lateral scapular slide test. In this cross-sectional study, shoulder active joint position sense, serving as shoulder proprioception, was measured using an isokinetic dynamometer. Upper extremity dynamic stability and hand grip strength were evaluated using an upper quarter modified star excursion balance test (UQ-mSEBT) and a handheld dynamometer. ResultsThe study found that the shoulder active joint position sense was significantly lower in the scapular dyskinesis group compared to the group without scapular dyskinesis (PExternal Rotation = 0.003, PInternal Rotation < 0.001, and PForward Flexion = 0.002). However, the two groups had no significant differences in UQ-mSEBT and hand grip strength scores. ConclusionsThe results showed that scapular dyskinesis could affect the sense of shoulder active joint position among asymptomatic overhead athletes. However, it did not affect their upper extremity dynamic stability and hand grip strength.

The Effect of Exercise-Induced Central Fatigue on Cervical Spine Joint Position Error, Strength, and Endurance.

Fatigue is common in sports, impairing performance and increasing injury risk, yet little is known regarding fatigue and concussion. Impaired neck neuromuscular function may contribute to concussion at baseline, where central fatigue may further impair neck function resulting in increased concussion risk. These effects may be magnified in athletes with a history of concussion. To determine the effect of exercise induced central fatigue on neck joint position error, strength, and endurance in healthy subjects and those with a history of concussion. The investigators hypothesized that EICF would have a negative effect on all variables. Healthy subjects were examined using a single factor, within-subjects repeated measures design. Concussion history subjects were examined using a single-subject design. Nineteen healthy subjects and five subjects with a history of concussion were recruited for the study. Cervical joint position error, muscle strength, and neck flexor endurance were tested before and after exercise induced fatigue. There was a significant increase in constant (p = 0.0027) and absolute joint position error (JPE) (p < 0.001); decrease in neck flexor endurance (p < 0.001); and decrease neck strength into cervical flexion (p = 0.01) in healthy subjects following fatigue. Among concussion history subjects, five demonstrated a significant increase in absolute and constant JPE (p < 0.05); four demonstrated a significant decrease in neck flexor endurance (p < 0.05); one in neck flexion muscle strength (p < 0.05); and three in neck extension and rotation muscle strength (p < 0.05) following fatigue. Cervical neuromuscular function deteriorated following fatigue in healthy subjects. Resulting impairments may affect force alterations in cervical control, potentially increasing concussion risk. Concussion history subjects descriptively demonstrated similar results, however further research should examine formal comparisons involving subjects with and without concussion history. 3b.