Mean Displacement Research Articles

Longitudinal Fluvial Dispersion of Coarse Particles: Insights From Field Observations and Model Simulations

AbstractIn this study, we use field observations augmented with model simulations to examine gravel dispersion over nine years (2007–2015) in Halfmoon Creek. The observations of flow, entrainment, and dispersion were used to develop a forward model utilizing the Einstein‐Hubbell‐Sayre (EHS) compound Poisson process. The observed mean virtual velocity of the tracer population slows down with cumulative excess energy after the 2010 large event. The forward model deviates from the observations in representation of tails, overpredicts mean displacements, and shows a narrower spatial distribution. The heavy‐tailed resting times indicate prolonged immobilization of some grains, suggesting the preferential movement of other most mobile grains. As such, 34% of most mobile grains constitute 50% of the total entrainments. The consideration of preferential movement explains the longitudinal spread but still overpredicts the displacement after the 2010 event. The model was then explored to consider additional transport‐related mechanisms causing deviations, such as reduction in virtual velocity, entrainment probability, and morphological trapping of meander bends, which helps to adequately recreate the observed dispersive behavior. The available historical flow records used for simulating dispersive behavior over multiple decades reveal an abrupt increase in displacements for exceptionally large events, suggesting the exhumation of deeply buried grains back in transport. The simulation results highlight the need for tracer studies with large sample sizes and improved recovery rates for longer time frames experiencing floods of widely varying magnitudes. Such models, inspired by Einstein's stochastic theory can be valuable for various river research applications.

A reproducible representation of healthy tibiofemoral kinematics during stair descent using REFRAME – Part II: Exploring optimisation criteria and inter-subject differences

Kinematic analysis is a central component of movement biomechanics, describing the relative motion of joint segments during different activities, in different subject cohorts, and at different timepoints. Establishing whether two sets of kinematic signals represent fundamentally similar or different underlying motion patterns is especially challenging, given 1) the lack of consensus around reference frame and joint axis definition, and 2) the substantial effect that minimal variations in frame position and orientation are known to have on signal magnitude and characteristics. As such, enormous variability in the reporting of tibiofemoral kinematics has resulted in joint movement patterns that remain controversially discussed. Previously, we demonstrated the ability of the REference FRame Alignment MEthod (REFRAME) to reorientate and reposition differently aligned local segment frames to achieve convergence in signals representing the same underlying motion, thereby offering a novel approach to consistently report joint motion. In this study, for the first time, we apply REFRAME to assess the rotational and translational in vivo tibiofemoral motion of ten healthy subjects during stair descent based on kinematic signals collected using a moving videofluoroscope. Kinematics were analysed before and after different REFRAME implementations, revealing generally neutral ab/adduction behaviour, accompanied by varying degrees of a sinusoidal int/external tibial rotation pattern over the activity cycle. Our data demonstrate that different selected implementations of REFRAME are able to highlight different characteristics of the motion patterns: Minimisation of the translational root-mean-square revealed proximodistal translation patterns with overall neutral progression, while anteroposterior translation showed seemingly different levels of correlation with flexion/extension in different subjects. On the other hand, REFRAME minimisation of translational variances exposed differences in the relative mean displacement between the femoral and tibial origins between subjects, highlighting differences in mean centre of rotation positions. This early application of REFRAME for providing an understanding of tibiofemoral kinematics demonstrates the potential of this novel approach to bring clarity to an otherwise complex representation of highly variable time-series signals, while highlighting the philosophical challenges of clinically interpretating kinematic signals in the first place.

Excellent clinical and radiological outcomes after arthroscopic reduction and double row-suture bridge for large-sized greater tuberosity fractures of the humerus.

Currently, there is limited information on the clinical outcomes of arthroscopic reduction and double-row suture bridge fixation for large greater tuberosity fractures of the proximal humerus. This study aimed to evaluate the radiological and clinical outcomes of arthroscopic reduction and double-row suture bridge fixation for these fractures, hypothesizing that arthroscopic reduction and double-row suture bridge fixation is a safe, effective and minimally invasive treatment for large greater tuberosity fractures. This retrospective study analysed patients with large greater tuberosity fractures (fracture fragment ≥30 mm in diameter) who underwent arthroscopic reduction and double-row suture bridge fixation and had a follow-up period exceeding 2 years. The anatomic reduction was confirmed by assessing the step-off on radiographs immediately after surgery, and the radiologic union time was recorded. At the final follow-up, range of motion and functional outcome scores were evaluated. Additionally, any surgery-related complications were evaluated. Fifteen patients with a mean follow-up of 57.7 ± 23.1 months were included in the study. The mean fracture fragment size was 32.5 ± 2.4 mm, with a mean displacement of 5.1 ± 1.6 mm. Immediately postsurgery, 13 of 15 patients (86.7%) had a fracture step-off of <3 mm, with an average union time of 3 months. At the final follow-up, patients demonstrated excellent outcomes, with an average forward flexion of 167 ± 9.7° and external rotation of 70 ± 16.3. Functional outcome scores showed significant improvement compared with preoperative scores (p < 0.001). No major surgery-related complications were reported. Arthroscopic reduction and double-row suture bridge fixation for large-sized greater tuberosity fractures is safe and shows good fracture reduction and excellent clinical outcomes. Therefore, this surgical method can be considered an alternative to open reduction for large greater tuberosity fractures. Level IV.

Partial coverage adhesive augmented sternal fixation and stabilization: A biomechanical analysis

Adhesive-augmented sternal fixation (AASF) has been investigated as an alternative to the clinical standard of cerclage wires; however, previous studies have focused on a full adhesive layer across the sternal midline, which acts as a barrier to bone healing. This study used a human cadaveric model to investigate if partial coverage AASF used in combination with wired fixation could provide adequate stability. Median sternotomies were performed on fifteen human cadaveric sterna. Three groups (n = 5) with varying adhesive coverage (50 %, 62.5 %, 75 %) of the sternal midline and traditional wiring were investigated. Cyclic lateral distraction loading of 10 N to 100 N was applied at 50 N/s. Every 30 cycles, the maximum load was increased by 100 N to a maximum of 500 N. Displacement was measured using transducers spanning the transection line at the manubrium, body, and xiphoid. Mean maximum total displacement (MMTD) for all groups was significantly below 2 mm (p < 0.001) with 1.49 mm ± 0.82 mm, 0.97 mm ± 0. 55 mm, and 0.67 mm ± 0.65 mm in the 50 %, 62.5 %, and 75 % groups respectively. MMTD in the 50 % group was significantly greater than MMTD in the 62.5 % and 75 % groups. AASF improved stability as coverage of the sternal surface with adhesive increased. Partial coverage of the sternal midline with adhesive may provide similar rigidity to a full layer while enabling earlier sternal ossification at the transection line compared to wiring alone.

Ultrasound Speckle Tracking Method Based on Gradient Optical Flow to Quantify Small Longitudinal Displacement, Shear and Longitudinal Strain in Peripheral Nerves

ObjectiveThis study aimed to develop, validate and test the clinical feasibility of ultrasound (US) speckle tracking method based on gradient optical flow for quantifying small longitudinal displacements, shear and strain in peripheral nerves. MethodsThe speckle tracking method was validated using seven thawed, fresh-frozen isolated cadaveric forearms. Longitudinal motion of the median nerve was captured using a high-frequency 22 MHz linear probe. An air bubble marker was inserted as a reference point for manual measurement comparison. The precision and accuracy of the method were assessed by comparing manual and automatic measurements. Clinical feasibility was tested on eight healthy subjects, measuring the longitudinal displacement of the median nerve during elbow extension and shoulder anteflexion. ResultsThe method demonstrated linearity, high precision and accuracy, particularly with a backtrace of five frames, reducing the displacement underestimation to 4%. In cadaveric models, the highest shear strain was observed at the nerve-tissue interfaces. In healthy subjects, the mean displacement of the median nerve was 3.3 ± 1.0 mm, with good inter-rater reliability (intraclass correlation coefficient = 0.87). ConclusionThe US speckle tracking method based on gradient optical flow effectively quantifies small longitudinal displacements and shear strain in peripheral nerves, with high precision and accuracy. However, the method could not detect longitudinal strain in nerves within the range of tested displacements. Future studies should investigate its applicability to smaller and deeper nerves and its usefulness in different pathological conditions.

Aggregation of adult parasitic nematodes in sex-mixed groups analysed by transient anomalous diffusion formalism.

Intestinal parasitic worms are widespread throughout the world, causing chronic infections in humans and animals. However, very little is known about the locomotion of the worms in the host gut. We studied the movement of Heligmosomoides bakeri, naturally infecting mice, and used as an animal model for roundworm infections. We investigated the locomotion of H. bakeri in simplified environments mimicking key physical features of the intestinal lumen, i.e. medium viscosity and intestinal villi topology. We found that the motion sequence of these nematodes is non-periodic, but the migration could be described by transient anomalous diffusion. Aggregation as a result of biased, enhanced-diffusive locomotion of nematodes in sex-mixed groups was detected. This locomotion is probably stimulated by mating and reproduction, while single nematodes move randomly (diffusive). Natural physical obstacles such as high mucus-like viscosity or villi topology slowed down but did not entirely prevent nematode aggregation. Additionally, the mean displacement rate of nematodes in sex-mixed groups of 3.0 × 10-3 mm s-1 in a mucus-like medium is in good agreement with estimates of migration velocities of 10-4 to 10-3 mm s-1 in the gut. Our data indicate H. bakeri motion to be non-periodic and their migration random (diffusive-like), but triggerable by the presence of kin.

Three-Dimensional Analysis of Vocal Fold Oscillations: Correlating Superior and Medial Surface Dynamics Using Ex Vivo Human Hemilarynges.

The primary acoustic signal of the voice is generated by the complex oscillation of the vocal folds (VFs), whereby physicians can barely examine the medial VF surface due to its anatomical inaccessibility. In this study, we investigated possibilities to infer medial surface dynamics by analyzing correlations in the oscillatory behavior of the superior and medial VF surfaces of four human hemilarynges, each in 24 different combinations of flow rate, VF adduction, and elongation. The two surfaces were recorded synchronously during sustained phonation using two high-speed camera setups and were subsequently 3D-reconstructed. The 3D surface parameters of mean and maximum velocities and displacements and general phonation parameters were calculated. The VF oscillations were also analyzed using empirical eigenfunctions (EEFs) and mucosal wave propagation, calculated from medial surface trajectories. Strong linear correlations were found between the 3D parameters of the superior and medial VF surfaces, ranging from 0.8 to 0.95. The linear regressions showed similar values for the maximum velocities at all hemilarynges (0.69-0.9), indicating the most promising parameter for predicting the medial surface. Since excessive VF velocities are suspected to cause phono-trauma and VF polyps, this parameter could provide added value to laryngeal diagnostics in the future.

Retinal displacement following direct versus indirect fluid exchange in pars Plana vitrectomy for rhegmatogenous retinal detachment.

To compare the occurrence and characteristics of retinal displacement following direct perfluorocarbon liquid (PFCL)-silicone oil (SO) exchange versus indirect PFCL for air and air for SO exchange methods during pars plana vitrectomy (PPV) in patients with rhegmatogenous retinal detachment (RRD). A comparative case series study was conducted on 58 eyes with recent RRD, undergoing standard three-port PPV with SO tamponade. Fluid exchange was performed using either direct or indirect methods. Postoperatively, a comprehensive ophthalmic examination and fundus autofluorescence (FAF) imaging were conducted at one month. The presence, amount, and direction of retinal displacement were assessed based on FAF imaging and compared between the direct and indirect fluid exchange groups. FAF imaging at one month revealed retinal displacement in 41.4% of eyes in the direct group and 62.1% in the indirect group, with no statistical difference between them (P = 0.537). However, the mean displacement was significantly higher in the indirect group (282.61 ± 110.83 µm) compared to the direct group (220.33 ± 39.67 µm, P = 0.04). The direction of displacement (downward or upward) did not differ significantly between the groups (P = 0.093). While the occurrence and location of postoperative retinal displacement did not significantly differ between direct and indirect fluid exchange methods during PPV for RRD, eyes treated with the direct method exhibited lower mean displacement compared to the indirect method. These findings suggest potential benefits of the direct exchange approach in minimizing retinal displacement following surgery.

Comparative Analysis of Dual-Task and Single- Task Balance Exercises in Improving Static Balance in Individuals with Anterior Cruciate Ligament Reconstruction

Introduction: Various balance exercises have been employed to enhance functional stability and balance in individuals who have undergone anterior cruciate ligament (ACL) reconstruction; however, no study has explored the use of dual-task balance exercises for these patients. This study compares the effects of dual motor task balance exercises and single-task exercises on the static balance indices of individuals with ACL reconstruction. Materials and Methods: In a single-blind randomized controlled trial, 27 subjects who had undergone ACL reconstruction were randomly divided into two groups: Dual-task and single- task balance exercises. Both groups performed their exercises three days a week for one month. Static balance indicators were assessed at the beginning and end of the treatment. Results: The results demonstrated that after the treatment, there was a statistically significant decrease in various center of pressure variables, including mean displacement in the anterior- posterior and medial-lateral directions, total path length, mean velocity of displacement, root mean square of displacement, and velocity. Furthermore, the knee injury and osteoarthritis outcome score significantly increased in both groups (P&lt;0.05). However, when comparing the two groups, no significant difference was observed after the treatment (P&gt;0.05). Conclusion: Dual-task and single-task motor exercises improve static stability and knee function levels in patients who have undergone ACL reconstruction. Meanwhile, the effectiveness of these exercise types does not significantly differ from each other.

The deltotrapezial fascia stabilizes the AC-Joint and its reconstruction restores the horizontal stability in AC-joint separations—a biomechanical comparison

BackgroundVarious techniques are available for the reconstruction of acromioclavicular joint (ACJ) dislocations, with the main focus being on restoration of the AC capsule or coracoclavicular (CC) ligaments. Recent research has underlined the significance of the deltotrapezial fascia (DTF) and related muscles as dynamic stabilizers of the ACJ. HypothesisReconstruction of the DTF increases the stability of the ACJ in the horizontal plane more than a complete transection of the fascia, while not restoring the stability of the native state. MethodsFive pairs of human cadaveric shoulders including the torsos were included in the study and underwent cyclic anterior-posterior loading using an electromechanical testing machine. The shoulders were put into three groups: group N (n = 10): native ACJ; group T (n = 10): ACJ with transected DTF; group R (n = 10): ACJ with reconstruction of the DTF after transection. The dislocation was recorded with an 3D optical measuring system. ResultsGroup N showed a mean horizontal displacement of 2.94 mm (± 1.26), group T showed a mean anterior displacement of 3.33 mm (± 1.37) and group R showed a mean anterior displacement of 2.95 mm (± 1.08). The mean anterior displacement for group T was significantly higher after every measured number of cycles compared with groups N and R. There was no significant difference in mean anterior displacement between groups N and R. ConclusionThe transection of the DTF results in significantly reduced stability in the horizontal plane of the ACJ. A reconstruction of the DTF restores the stability of the native ACJ in the horizontal plane. Further clinical and biomechanical investigations should focus on reconstruction techniques of the DTF.

Three-dimensional morphometry of the human thoracic aorta using centerline analysis based on least-squares plane fitting

ObjectiveA novel approach to 3-dimensional morphometry of the thoracic aorta was developed by applying centerline analysis based on least-squares plane fitting, and a preliminary study was conducted using computed tomography imaging data. MethodsWe retrospectively compared 3 groups of patients (16 controls without aortic disease, and 16 cases each with acute type B aortic dissection and congenital bicuspid aortic valve). In addition to the standard assessment indices for curvature κ and torsion τ, we conducted coordinate transformation based on the least-squares plane, divided the centerline into 3 representative features (transverse, anterior-posterior, and longitudinal displacements), and analyzed the overall and local displacement in each direction. The transverse displacement, represented by the distance of the centerline from the least-squares plane, was curve-fitted to the damped oscillation waveform. Thereafter, damped oscillation parameters were compared for each group. ResultsCurvature κ exhibited a bimodal distribution, with peaks observed in the ascending aorta and aortic arch, and torsion τ exhibited a transition from positive to negative values in the arch. There were significant differences in the mean displacement between the groups for each direction (transverse P = .0083, anteroposterior P = .010, longitudinal P = 1.32 × 10−6). Furthermore, interval integral analysis revealed that several intervals exhibited significant differences between groups in each direction. The amplitude of damped oscillation parameters was significantly larger in the bicuspid aortic valve group than in the control and type B aortic dissection groups. ConclusionsThe novel analytical approach permitted a quantitative assessment of the 3-dimensional morphological differences between the control, type B aortic dissection, and bicuspid aortic valve groups.

Neutrino halo profiles: HR-DEMNUni simulation analysis

Using the high-resolution HR-DEMNUni simulations, we computed neutrino profiles within virialized dark matter haloes. These new high-resolution simulations allowed us to revisit fitting formulas proposed in the literature and provided updated fitting parameters that extend to less massive haloes and lower neutrino masses than previously in the literature, in accordance with new cosmological limits. The trend we observe for low neutrino masses is that, for dark matter halo masses below ∼ 4 × 1014 h -1 M ⊙, the presence of the core becomes weaker and the profile over the whole radius is closer to a simple power law. We also characterised the neutrino density profile dependence on the solid angle within clustered structures: a forward-backward asymmetry larger than 10% was found when comparing the density profiles from neutrinos along the direction of motion of cold dark matter particles within the same halo. In addition, we looked for neutrino wakes around halo centres produced by the peculiar motion of the halo itself. Our results suggest that the wakes effect is present in haloes with masses greater than 3 × 1014 h -1 M ⊙ where a mean displacement of 0.06h -1Mpc was found.

Synchronous 3D Imaging of the Medial and Superior Vocal Fold Surface in an excised human Hemilarynx.

This study investigates relationships between the oscillation behavior of the medial and superior vocal fold (VF) surfaces during sustained phonation in a human cadaver hemilarynx. An experimental test stand synchronously captured the medial and superior VF surfaces of a human ex vivo hemilarynx during sustained phonation using two high-speed camera setups in 24 experimental settings. The 3D coordinates of the medial VF surface were reconstructed by triangulation of sewn-in marker points, while laser-based reconstruction was used for the superior VF surface. Correlation analysis and linear regression were used to quantify the connections of the mean and maximal vertical and lateral VF displacements and the VF velocities. Additionally, stepwise linear regression was used to analyze the impact of the measurement variables mean flow rate, adduction and elongation. Strong linear relationships between all of the tested corresponding parameter pairs of the superior and medial VF surfaces were found (p<.001). Mean and maximum vertical displacements of the medial surface were both approximately 50% of the superior surface. The mean lateral displacements for the medial surface were 12% below the superior surface but 12% higher for the maximum values. The mean and maximum VF velocities were 32% and 36% lower for the medial surface. The suggested multi-modal test stand allows efficient, comprehensive analysis of human hemilarynges and provides promising information about the interaction of the different VF areas and opens up the systematic analysis of multiple hemilarynges. In future, our results could integrate into ENT diagnostics using 3D laryngoscopy where the hidden medial VF surface dynamics may be predicted from the observable superior surface.

Three-dimensional assessment of low-level laser therapy on orthodontic miniscrew displacement using CBCT: a retrospective study

BackgroundThis study aimed to assess the effect of Low-Level Laser Therapy (LLLT) on sagittal, transverse and vertical Orthodontic miniscrew displacement.Materials and methodsThe study included CBCTs from the records of 12 adult patients who underwent upper first premolar extraction and canine retraction with orthodontic miniscrews for maximum anchorage. The miniscrews on one side received LLL, while the other side served as a control. The Low-Level Laser was applied to assess its effect on the displacement of the miniscrews. The used CBCTs have been taken at two-time points: immediately after miniscrew insertion (T0) and four months after the start of canine retraction (T1) with a total of 24 CBCTs. Miniscrew displacement was assessed by measuring head (HMS) and tail (TMS) displacement to the axial, coronal and mid-sagittal planes on the CBCT at the two time points. Miniscrews displacement (T1-T0) was compared between LLL side and control side. Comparisons were performed using paired samples t-test. The significance level was set at p-value < 0.05. The reproducibility of measurements was assessed by intraclass correlation coefficient (ICC).ResultsAfter four months of canine retraction, HMS and TMS from both laser and control sides showed significant three-dimensional displacement at p < 0.05. No significant difference in mean displacement in the vertical, sagittal, nor transverse planes between both sides was elicited.ConclusionLLL application in the used protocol does not affect the amount of miniscrew displacement in any of the three planes of space. Miniscrew displacement was significant in both groups.

Effects of attentional focus on quiet standing balance control in individuals with non-specific chronic low back pain

Despite the widespread research about the effects of attentional focus on balance control in different populations, to the best of our knowledge, no study has yet investigated the effects of attentional focus instructions on balance control in individuals with chronic low back pain (CLBP). Therefore, this study was aimed to compare the effects of internal focus (IF) and external focus (EF) of attention on quiet standing balance control between individuals with CLBP and healthy controls. Twenty individuals with CLBP and 20 healthy controls were enrolled in this quasi-experimental study. The participants were asked to stand still with eyes open and eyes closed while performing three tasks: baseline standing with no focus instructions, internally focusing on their feet, and externally focusing on two markers were placed on the force platform. Statistical analyses showed a significant main effect of group for mean total velocity (p = 0.02), area (p = 0.01), and displacement in mediolateral (ML) direction (p = 0.003). Moreover, a significant main effect of vision was observed for mean total velocity (p < 0.001), area (p < 0.001), and displacement in anteroposterior (AP) (p < 0.001) and ML directions (p < 0.001). Also, the results revealed a significant main effect of attentional focus for mean total velocity (p < 0.001), area (p < 0.001), and displacement in AP (p < 0.001) and ML directions (p = 0.01). Our results showed that in both healthy controls and individuals with CLBP, EF led to improve quiet standing balance control compared to IF and control conditions. From a clinical perspective, it may be useful for physical therapists to consider the use of instruction cues that direct performer's attention away from the body for improving quiet standing balance control in individuals with CLBP.

Comparative analysis of delivered and planned doses in target volumes for lung stereotactic ablative radiotherapy

BackgroundAdaptive therapy has been enormously improved based on the art of generating adaptive computed tomography (ACT) from planning CT (PCT) and the on-board image used for the patient setup. Exploiting the ACT, this study evaluated the dose delivered to patients with non-small-cell lung cancer (NSCLC) patients treated with stereotactic ablative radiotherapy (SABR) and derived relationship between the delivered dose and the parameters obtained through the evaluation procedure.MethodsSABR treatment records of 72 patients with NSCLC who were prescribed a dose of 60 Gy (Dprescribed) to the 95% volume of the planning target volume (PTV) in four fractions were analysed in this retrospective study; 288 ACTs were generated by rigid and deformable registration of a PCT to a cone-beam computed tomography (CBCT) per fraction. Each ACT was sent to the treatment planning system (TPS) and treated as an individual PCT to calculate the dose. Delivered dose to a patient was estimated by averaging four doses calculated from four ACTs per treatment. Through the process, each ACT provided the geometric parameters, such as mean displacement of the deformed PTV voxels (Warpmean) and Dice similarity coefficient (DSC) from deformation vector field, and dosimetric parameters, e.g. difference of homogeneity index (ΔHI, HI defined as (D2%-D98%)/Dprescribed*100) and mean delivered dose to the PTV (Dmean), obtained from the dose statistics in the TPS. Those parameters were analyzed using multiple linear regression and one-way-ANOVA of SPSS® (version 27).ResultsThe prescribed dose was confirmed to be fully delivered to internal target volume (ITV) within maximum difference of 1%, and the difference between the planned and delivered doses to the PTV was agreed within 6% for more than 95% of the ACT cases. Volume changes of the ITV during the treatment course were observed to be minor in comparison of their standard deviations. Multiple linear regression analysis between the obtained parameters and the dose delivered to 95% volume of the PTV (D95%) revealed four PTV parameters [Warpmean, DSC, ΔHI between the PCT and ACT, Dmean] and the PTV D95% to be significantly related with P-values < 0.05. The ACT cases of high ΔHI were caused by higher values of the Warpmean and DSC from the deformable image registration, resulting in lower PTV D95% delivered. The mean values of PTV D95% and Warpmean showed significant differences depending on the lung lobe where the tumour was located.ConclusionsEvaluation of the dose delivered to patients with NSCLC treated with SABR using ACTs confirmed that the prescribed dose was accurately delivered to the ITV. However, for the PTV, certain ACT cases characterised by high HI deviations from the original plan demonstrated variations in the delivered dose. These variations may potentially arise from factors such as patient setup during treatment, as suggested by the statistical analyses of the parameters obtained from the dose evaluation process.

Influence of Grip Width on the Load-Velocity Relationship and 1 Repetition Maximum Value in the Bench Press Exercise: A Comparative and Reliability Analysis of Mean Velocity Vs. Mean Propulsive Velocity Vs. Peak Velocity.

Herrera-Bermudo, JC, Puente-Alcaraz, C, Díaz-Sánchez, P, González-Badillo, JJ, and Rodríguez-Rosell, D. Influence of grip width on the load-velocity relationship and 1 repetition maximum value in the bench press exercise: a comparative and reliability analysis of mean velocity vs. mean propulsive velocity vs. peak velocity. J Strength Cond Res XX(X): 000-000, 2024-This study aimed to analyze the reliability and compare the load (percentage of 1 repetition maximum [%1RM])-velocity relationship, bar displacement (DIS), the 1RM, and the velocity attained against the 1RM value (V1RM) in the bench press exercise using 3 different bar grip widths: narrow (120% of the biacromial distance [BD]), medium (160%), and wide (200%). A group of 54 healthy, physically active men randomly performed a total of 6 incremental tests (1 week apart) up to 1RM (2 with each bar grip width) on a Smith machine. The mean velocity (MV), mean propulsive velocity (MPV), peak velocity, and DIS were recorded for the subsequent analysis. The 3 velocity variables showed high relative (intraclass correlation coefficient: 0.90-0.97) and absolute (coefficient of variation: 2.21-9.38%) reliability in all grip widths against all relative loads. The 1RM value and the V1RM present high absolute and relative reliability in all grip widths. There are no significant differences in the value of 1RM and V1RM between grip widths. High relationships were observed between the relative load (%1RM) and velocity variables, with MPV showing the best fit. Significant greater values in MPV, MV, and DIS associated with each %1RM were observed for narrow and medium compared with wide grip width. In conclusion, our results suggest that the 3 velocity variables were highly reliable at the different grip widths used against all relative loads. In addition, there was a tendency to reach higher MV, MPV, and DIS values as the grip width decreased. Therefore, this factor should be considered for the assessment and design of training.

The Effect of Planovalgus on Balance and Motor Function in Children With Cerebral Palsy

Objective Lower limb deformity in children with cerebral palsy (CP) is a common musculoskeletal problem and planovalgus is the most prevalent, characterized by talus median subluxation, calcaneal valgus, and supinated forefoot. According to studies, one issue in orthopedics and pathology is the accurate diagnosis and proper treatment of planovalgus deformity in children with bilateral spastic cerebral palsy, which has attracted researchers’ attention. Accordingly, the present study investigates the effect of planovalgus deformity on the motor performance and balance of these children. Materials &amp; Methods This cross-sectional study employed a descriptive-analytical design. The convenient sampling method was used among children with bilateral spastic cerebral palsy, diagnosed with unilateral planovalgus, who were referred to the clinics of the University of Social Welfare and Rehabilitation Sciences (Nezam Mafi) and occupational therapy clinics from September 2022 to February 2023 in Tehran City, Iran. Meanwhile, all participants were willing to cooperate in this research. A total of 27 participants were evaluated by an occupational therapist based on the specified criteria and gross motor function classification system (GMFCS), which included the assessments of balance, muscle strength, range of motion, and pain. Data analysis was done using the SPSS software, version 16. Results The results revealed a statistically significant difference between the mean range of motion of ankle dorsiflexion and knee extension between the two limbs (P&lt;0.001). The mean muscle strength of the quadriceps and ankle plantar flexors indicated a statistically significant difference in the affected limb (P&lt;0.001). Additionally, the mean displacement of the center of pressure of the foot also demonstrated a statistically significant difference regarding topographical involvement (P&lt;0.001). Conclusion Planovalgus deformity is one of the most common ankle deformities, which is of great concern for children with cerebral palsy. The results obtained from the assessments of the child’s balance and motor function demonstrated the importance of assessment strategies and early interventions to achieve better rehabilitation outcomes for children with CP and planovalgus deformity.

Stability before and after percutaneous anterior medullary fixation of lateral compression 1 and 2 pelvic ring disruptions: Should surgeons prioritize the anterior ring?

Surgical intervention for lateral compression (LC) 1 and 2 pelvic ring fractures is controversial. Posterior ring stabilization remains the most common mode of initial fixation. However, greater mechanical instability is observed in the anterior component of LC pelvic fractures. This study tested whether reduction and percutaneous superior ramus fixation will decrease the instability of LC pelvic fractures on intraoperative fluoroscopic imaging. All adult patients (≥ 18 years) presenting with either a Young-Burgess LC1 or LC2 pelvic ring disruption treated operatively with percutaneous anterior followed by posterior fixation by a single surgeon from July 2021 to June 2023 were retrospectively reviewed. Displacement of the anterior ring to intraoperative manual internal rotation stress examination under fluoroscopy was compared before and after anterior pelvic ring reduction and fixation and prior to posterior pelvic ring fixation. Pre- and post-operative visual analog scores (VAS) for pain were also compared. Twenty-one patients with a mean age of 48.7 years were included. Fifteen patients (71.4%) presented with an LC1, and six (28.6%) with an LC2 injury patterns. Anterior pelvic fixation alone provided 7.5mm reduction in mean displacement of the anterior pelvic ring (pre-operative = 9.2 mm vs. post-operative = 1.6 mm, p < 0.001). VAS significantly decreased from 7.2 one-day pre-operatively to 2.2 twenty-four h post-operatively (p < 0.001). Reduction and fixation of the anterior pelvic ring prior to posterior fixation for LC1 and LC2 pelvic ring disruptions substantially improves mechanical stability on intraoperative stress examination. Combination of percutaneous anterior and posterior fixation significantly decreased VAS above the MCID 24 h after stabilization.

The effect of upper trapezius trigger points dry needling on postural control in patients with chronic neck pain

ObjectiveMyofascial neck pain, which strongly affects the upper trapezius muscle, is treated by physiotherapists with dry needling. The purpose of this study was to investigate the effect of upper trapezius trigger points (TrPs) dry needling on postural control and balance in chronic neck pain. DesignRandomized controlled clinical trial. SubjectsThirty individuals with chronic neck pain (more than 3 months), aged 18–40 years, neck disability index (NDI) > 10, and pain intensity (PI) between 3 and 6 who have TrP in the upper trapezius. MethodThirty individuals were randomly assigned into 2 groups, (i) 15 receiving intervention (real dry needling), and (ii) 15 in the sham group (sham dry needling). Outcomes were range of neck movements, neck disability index, pain intensity, and the mean and standard deviation as well as maximum velocity of center of pressure displacement in the anterior-posterior and medio-lateral directions during balance task on the force plate (1 leg stance and closed eyes) before the intervention and after the fifth and fifteenth (follow-up) days. InterventionUpper trapezius dry needling was applied for 3 sessions occurring every other day in a week. ResultNo significant differences were seen between the 2 groups in mean displacement, standard deviation, or maximum velocity in the anterior-posterior and medial-lateral axis and range of motion (ROM) except for left lateral bending; however, a significant difference was observed between the 2 groups in pain intensity and neck disability index. ConclusionDry needling on the upper trapezius TrPs does not change postural control but decreases pain and disability.