Magnitude Angle Research Articles

Statistical characteristics of realistic fiber misalignments of unidirectional composites: Fitting distributions and scanning length effects

This paper presents a comprehensive study on the statistical characteristics of angle, tortuosity, curvature and wave magnitude to deepen the understanding of realistic fiber misalignments within unidirectional composites. A feasible fiber path reconstruction procedure has been optimized, which can be applicable to other types of composites. The high-resolution micrographs are acquired through X-ray computed tomography. The individual fiber segmentation is implemented using a U-Net deep learning method, and the fiber trajectories are reconstructed with the aid of a tracing algorithm. The stepped fiber trajectories are slightly smoothed and a polynomial fitting formula is adopted to quantitatively describe the fiber paths. The statistical characteristics corresponding to the differential tortuosity, misalignment angle, spatial curvature and wave magnitudes are comprehensively analyzed, with emphasis on their fitting distributions and scanning length effects. The collected data indicate that the statistical distributions of differential tortuosity and angle, curvature, and wave magnitude can be well fitted by normal, lognormal and Weibull equations, respectively. Particularly, the differential tortuosity and wave magnitude are overall features of individual fiber trajectory, which are highly correlated with the scanning length. In contrast, the angle and curvature are local features, so a smaller scanning length could obtain convergent results.

Application of computational methods in problems of aeroballistics. determination of conjugate throwing angles and construction of ballistic trajectories

The problem of aeroballistics of non-reactive artillery projectiles is studied by means of a simplified mathematical model. The following problems are considered as separate subproblems: initial value problem, determination of the horizontal range of a projectile (4th order Runge-Kutta method with modification of polynomial interpolation); optimization problem (Powell's method), determination of the angles of maximum range — the throwing angles at which the maximum horizontal range is achieved; the boundary value problem (shooting method with Newton-Raphson method/ secant method/ polynomial interpolation), determination of throwing angles at a given distance and the problem of finding conjugate trajectories — the low and high angled trajectories, which achieve the same horizontal range of the projectile at different throwing angles; the inverse geodesy problem (Vincenty's formulae), determination of the geodesic distance between two geographical points on the WGS-84 non-spherical Earth model. The following characteristics are graphically illustrated as a function of throwing angles: horizontal and vertical ranges, maximum vertical and horizontal velocity components, magnitudes of terminal velocities, impact angle, and flight time of projectiles. The existence of conjugate trajectories is established and the strategy of sequential firing of projectiles with the aim of simultaneously hitting the target along different trajectories is determined. The programming of the numerical methods, the algorithm for solving the problem, and the visualization elements were implemented using the MATLAB application package, and the developed methodology and software have demonstrated their effectiveness and the possibility of their practical application.

Comprehensive analysis of strabismus reoperations: clinical insights and progression factors

BackgroundTo compare and analyze clinical characteristics of patients undergoing two surgeries and multiple surgeries and explore relevant factors to lay the foundation for clinical prediction.MethodsA retrospective analysis was conducted on clinical data from all patients who underwent twice and multiple strabismus surgeries at Tianjin Eye Hospital between October 2012 and September 2021. Patients were divided into Group A (two surgeries) and Group B (more than two surgeries) based on the cumulative number of surgeries performed. Clinical details at the first recurrence, including sex, age, native place, overall medical history, onset time, visual acuity, affected muscle(s), etc., were documented. Non-parametric tests and chi-square tests were used to analyze clinical characteristics in each group. Binary and ordered logistic regression analysis assessed parameters associated with multiple reoperations. A linear mixed-term model observed factors impacting affected muscle(s) during surgery. Researchers examined clinical traits related to secondary strabismus variables.ResultsAmong the 910 included patients, 840 required two surgeries (Group A) and 70 underwent more than two surgeries (Group B). Significant differences were found in age, onset time, interval time, and secondary factors. Regression analysis highlighted the significant impact of interval time on the reoperation rate, effectively predicting outcomes in patients with concomitant strabismus. Other ophthalmoplegia and secondary factors significantly influenced reoperation rates in patients with non-concomitant strabismus. Interval time, esotropia, and exotropia were linked to concomitant secondary strabismus patients, while the number of surgeries, DVD, esotropia, exotropia, and esotropia V-pattern were associated with non-concomitant secondary strabismus patients. In a longitudinal study, patients with multiple surgeries showed a correlation between the vertical deviation angle magnitude and the number of involved extraocular muscles. Regression analysis revealed that in patients with concomitant strabismus, interval time, exotropia, and esotropia influenced the total number of muscles during surgery. For patients with non-concomitant strabismus, interval time, secondary factors, and SOP impacted the total number of muscles during surgery.ConclusionsInterval time in patients with concomitant strabismus, as well as secondary and other ophthalmoplegia in non-concomitant strabismus, are the main factors for multiple reoperations.

Triple Jump Performance Parameters and Inter-Limb Asymmetry in the Kinematic Parameters of the Approach Run in International and Paralympic-Level Class T46/T47 Male Athletes

Background/Objectives: The triple jump is included in the Paralympic Athletics competition. The aim of the research was to examine the relationship of the phase ratios and the inter-limb asymmetry in the spatiotemporal parameters of the approach run in Paralympic and international-level Class T46/T47 triple jumpers. Methods: Eleven Class T46/T47 male athletes were recorded during the examined competitions. Step length (SL), frequency (SF), and average velocity (ASV) for the late approach run as well as the length and the percentage distribution of each jumping phase (hop, step, jump) were measured using a panning video analysis method. The inter-limb asymmetry was estimated using the symmetry angle. Results: No significant inter-limb asymmetry was found (p > 0.05). In addition, SL, SF, and ASV were not different (p > 0.05) between the steps initiated from the ipsilateral and the contralateral leg regarding the impaired arm. However, the direction of asymmetry for SF was towards the ipsilateral leg to the impaired arm in the majority of the examined athletes. The maximum speed of the approach was correlated with the triple jump distance and the magnitude of asymmetry for AVS was correlated with the vertical take-off velocity and angle for the step. Conclusions: Since the distance of the triple jump related with the peak approach speed added the negative correlation of peak approach speed with the magnitude of the symmetry angle for SL, it is suggested to minimize the asymmetries in the step characteristics during the approach run to improve triple jump performance in Class T46/T47 jumpers.

Research on vector bending sensors based on taper-drawn seven-core fiber Bragg grating

We present a novel vector bending sensor that enables simultaneous measurement of the bending response in six outer cores of a seven-core fiber (SCF) without the need for fan-in/fan-out configurations. Utilizing femtosecond laser technology, we inscribe seven Fiber Bragg Gratings (FBGs) with distinct wavelengths across the SCF cores. The sensor’s tapering process, tailored for the bending sensing scenario, effectively combines the reflection peaks of the FBGs into one detection channel, thereby substantially improving the measurement efficiency. Our experimental results demonstrate a strong directional dependence of the bending response, with a maximum sensitivity of 127 pm/m−1. The bending angle and curvature magnitude are reconstructed by analyzing the wavelength shifts of any two non-diagonal outer cores, offering a versatile solution for real-time monitoring applications. This sensor design, by eliminating the need for additional fan-in/fan-out devices, simplifies the system architecture and reduces both measurement time and sensor size, making it highly suitable for applications in precision manufacturing, environmental monitoring, and robotics.

On the implementation of acollinearity in PET Monte Carlo simulations

Objective.Acollinearity of annihilation photons (APA) introduces spatial blur in positron emission tomography (PET) imaging. This phenomenon increases proportionally with the scanner diameter and it has been shown to follow a Gaussian distribution. This last statement can be interpreted in two ways: the magnitude of the acollinearity angle, or the angular deviation of annihilation photons from perfect collinearity. As the former constitutes the partial integral of the latter, a misinterpretation could have significant consequences on the resulting spatial blurring. Previous research investigating the impact of APA in PET imaging has assumed the Gaussian nature of its angular deviation, which is consistent with experimental results. However, a comprehensive analysis of several simulation software packages for PET data acquisition revealed that the magnitude of APA was implemented as a Gaussian distribution.Approach.We quantified the impact of this misinterpretation of APA by comparing simulations obtained with GATE, which is one of these simulation programs, to an in-house modification of GATE that models APA deviation as following a Gaussian distribution.Main results.We show that the APA misinterpretation not only alters the spatial blurring profile in image space, but also considerably underestimates the impact of APA on spatial resolution. For an ideal PET scanner with a diameter of 81 cm, the APA point source response simulated under the first interpretation has a cusp shape with 0.4 mm FWHM. This is significantly different from the expected Gaussian point source response of 2.1 mm FWHM reproduced under the second interpretation.Significance.Although this misinterpretation has been found in several PET simulation tools, it has had a limited impact on the simulated spatial resolution of current PET scanners due to its small magnitude relative to the other factors. However, the inaccuracy it introduces in estimating the overall spatial resolution of PET scanners will increase as the performance of newer devices improves.

Study on quasi-static tensile mechanical properties of biomimetic helicoidal composite laminates

Abstract Numerous biomaterials exhibit intricate helicoidal structures renowned for their exceptional toughness. This study drew inspiration from the collagen fiber structure found in the scales of coelacanths to design composite laminates featuring double helicoidal layup configurations with varying pitch angles. A damage evolution model with damage initiation and linear stiffness degradation based on the Hashin failure criterion was used to describe the damage behavior of the materials. The impact of varying pitch angles on the quasi-static tensile properties of double helicoidal composite laminates is investigated. The results show that the magnitude of the pitch angle has a significant effect on the tensile properties of the laminates, and the tensile modulus of double composite laminates is highest when the pitch angle is 90°.

Distribution of angle alpha and angle kappa offsets among adult candidates for cataract surgery.

The current study aimed to describe the distribution of angle alpha and angle kappa offsets as well as their associated ocular biometric parameters in a large population of candidates for cataract surgery. This cross-sectional retrospective study included 8,119 eyes of 4,781 candidates for cataract surgery (mean age 70.7 ± 12.9 years). There were 49.9% right eyes, and 53.0% patients were females. The angles offset and ocular biometric parameters were measured by the IOLMaster 700 (Carl Zeiss Meditec, AG, Germany). Patient's age and gender, and most of their ocular biometric measurements were similar for the right and left eyes except for pupil diameter (4.01 ± 1.18 vs. 3.92 ± 1.14 mm, respectively, P< 0.001). The angle alpha offset magnitude was similar for the right and left eyes (0.50 ± 0.20 and 0.51 ± 0.21 mm, P= 0.08), whereas the angle kappa offset magnitude was greater in the right eyes (0.37 ± 0.21 vs. 0.33 ± 0.20 mm, P< 0.001). The angle kappa offset magnitudes were greater in the right eyes compared to the left eyes for both males (0.36 ± 0.21 vs. 0.33 ± 0.21 mm, respectively, P< 0.001) and females (0.37 ± 0.20 vs. 0.34 ± 0.20 mm, respectively, P< 0.001). The offset magnitudes of both angles varied significantly according to gender, eye laterality, angle location, and biometric parameters (e.g., axial length). The offset magnitudes of both angles were positively correlated in both right and left eyes. The offset magnitudes of both the angle alpha and angle kappa present significant variations according to gender, eye laterality, angle location, and biometric parameters, such as AL. These values are also population-specific.

Transport enhancement in the laminar rotating disk boundary layer

Enhanced momentum and heat transport in a three-dimensional rotating disk boundary layer due to the consideration of a wavy disk surface is an already known fact in the literature. Such a transport enhancement is primarily associated with two fundamental attributes of the wavy disk: the increased surface area and the enhanced convection due to the surface undulations. However, there exists no further information about their individual role, mutual interaction, and individual share in enhancing the convective transport in the rotating disk boundary layer. This study aims to investigate these facts in detail by considering radially heterogeneous different wavy configurations on the disk surface. It is revealed that the said attributes contribute non-trivially to enhance the transport phenomena. Their impactful role is identified due to the strengths of circumferential and crossflow velocity components, the magnitude of flow swirl angle, and hence due to the coefficients of skin friction and their inter relationship. In this regard, a fundamental benchmark regarding the relative strength of the two coefficients of skin friction is identified from the flat disk case. Decisive observations regarding the impact of surface undulations and the increased surface area of the wavy disk on the enhanced convective transport are made with the aid of this benchmark. It is observed that the enhanced transport phenomena, especially the heat transfer, mainly depend upon the further dominance of the circumferential velocity component. In the situations of increased dominance of rotational flow Kw&amp;gt;Kf, the increased convection and surface area collectively contribute to enhance the thermal transport while in a reverse situation Kw&amp;lt;Kf the convection contributes adversely by even reducing the impact of the increased surface area. In the neutral situation where the dominance of rotational velocity is neither increased nor decreased (i.e., Kw≈Kf), any increase in the transport phenomena is wholly due to the increased surface area. Therefore, the presence of surface undulations or increase in surface area is not the only criterion for an optimum rise in the transport phenomena, rather the impact of surface undulations on the velocity profiles is important which is manipulated due to their positioning on the disk surface. It is observed that the presence of surface undulations in the central and intermediate regions on the disk surface causes to increase the gradients of the crossflow velocity while their presence in the near rim location causes to enhance the gradients of the circumferential velocity. Thus, the configurations that have higher undulations in the near rim region outperform the other configurations.

Influence of regularly repeated asymmetric load on the locomotor system in sweep rowers

ABSTRACT This study aims to objectively evaluate the trunk posture of sweep rowers (bow-side rowers/stroke-side rowers) and compare the results with scull rowers and non-rowing controls. Sixty-four healthy individuals divided into four groups were assessed using a DIERS formetric III 4D device that is based on a method of moiré topography. There were seven parameters observed in an assessment of standing posture, and eight parameters were studied for an evaluation of posture during the gait cycle. In comparison with non-rowing controls and scull rowers, stroke-side rowers showed significantly greater rotational deviation of the trunk at the L3 vertebra level and a greater magnitude of scoliosis angle during walking throughout the single support phase on the left leg (p < 0.05). Stroke-side rowers also demonstrated greater magnitude of scoliosis angle than non-rowing controls in double support phase in the transition from the left to the right leg (p < 0.05). Moreover, as opposed to non-rowing controls, stroke-side rowers and scull rowers showed significantly greater values of coronal imbalance (p < 0.05). Bow-side rowers differed from non-rowing controls and scull rowers in a significantly greater magnitude of scoliosis angle throughout the single support phase on the left leg (p < 0.05). Trial registration number: clinicaltrials.gov (identifier: NCT05685563).

Determination and characterization of the junction angles in river channels in Brazil with Google Earth Pro imagesn angles in river channels in Brazil with Google Earth Pro images

The determination of the junction angles and the river dynamics that form them have been studied since the 1930s. These studies normally have three approaches: reduced models, field investigation, and numerical simulation. To collaborate the scientific advances in this topic, the present study proposes a new methodology to determine junction angles in river channels, based on the Cosine Law, employing high-resolution remote sensing imagery. To verify your performance, 135 confluences located in six Brazilian biomes have been analyzed. These confluences were characterized with different magnitudes of channel width and different angles. Thus, relationship between width of the channels and their junction angles were evaluated, it has been obtained values α between 79° and 101°, values β between 133° and 150° and values γ between 117° and 140°. Results show that the channel width influences the magnitude of the junction angles.

Pengaruh Sudut Terhadap Besar Resultan Gaya Vektor: Kajian Eksperimental Menggunakan Praktikum Cookbook Laboratory

Vectors are fundamental concepts in mathematics and physics that play a crucial role in various scientific and engineering applications. This study investigates the relationship between the angle and magnitude of the resultant force vector using the Cookbook Laboratory practical approach. The experiment involved combining two forces at different angles and measuring the resultant force. The results indicate a linear relationship between the angle and magnitude of the resultant force, suggesting that as the angle increases, the magnitude of the resultant force also increases. However, this finding contradicts the theoretical prediction of an inverse relationship. This discrepancy is attributed to experimental limitations, particularly parallax error, which may have affected the accuracy of the measurements. Further experiments are recommended to minimize parallax error and obtain more accurate results. A thorough understanding of vector concepts and measurement techniques is essential for comprehending the relationship between angle and resultant force magnitude. Keywords: Angle; Cookbook Laboratory; Resultant Force; Vector.

PMUs data based detection of oscillatory events and identification of their associated variable: Estimation of information measures approach

Information theory can be a useful tool for quantifying the perturbations in the associated state variables at the time of disturbance occurrence. The study introduces a framework for the spectral decomposition of multivariate information measures to detect initiation of low frequency oscillations (LFOs), caused due to physical events in the power grid. A frequency-specific quantification of the information is shared between a target variable and two source variables from their time series data. Initially, the approach is applied on different synthetic test signals having different oscillatory frequency modes and decay time constant. Then, approach is extended on PMUs signals. The combination of cross-spectral and information-theoretic approaches is applied for the multi-variable analysis of PMUs signals from the same bus. The interdependence among the frequency, voltage angle and voltage magnitude, corresponding to specific oscillations, manifested due to cause-effect relationships obtained in terms of statistics is estimated. The dynamics in terms of unique (interaction), redundant and synergetic information is determined with the contribution from two of these three signals as source variables to target variable (frequency/voltage angle). This provides a direct coupling to identify driver-response relationships between source variables and target variable to indicate the onset of LFOs, following physical events in power network. The extension of approach among the variables from different buses aids to identify the responsible area of event occurrence.

Study on Multi-Scale Cloud Growth Characteristics of Frustoconical Dispersal Devices

This study aims to understand cloud growth behavior and enhance cloud safety and reliability by investigating the design of cloud dispersal devices. Based on the experimental results and simulation results, this study analyzes the dispersion characteristics of cloud materials within a frustoconical device with a semi-cone angle ranging from 0° to 10° across multiple scales. The collision aggregation model for cloud particles and the multi-scale coupling mechanism for cloud growth are established. The research shows that the semi-cone angle of the device extends the effective cloud growth duration and enlarges the cloud macroscopic size. At the mesoscopic scale, vortex phenomena are observed, causing particles to converge within the cloud, resulting in collisions and aggregation. The vortices enhance the continuity of the cloud concentration. The magnitude of these vortices demonstrates a positive correlation with the magnitude of the semi-cone angle of the dispersal device. For a macroscopically stable cloud, the high-concentration area within the cloud moves outward radially with an increase in the semi-cone angle. This study provides a theoretical foundation for cloud morphology control technology, contributing to enhancing the safety and reliability of cloud systems.

Ultra-Generalized Continuous Class F Power Amplifier with Finite Third-Harmonic Load Impedance

This paper proposes the ultra−generalized continuous class F (UCCF) mode, which combines the influences of the drain current conduction angle and overdriven transistor on the drain current waveform to achieve a broader finite third-harmonic load impedance space. The UCCF mode uses α to describe the magnitude of the drain current conduction angle and pcr to describe the drain current peak-clipped ratio. An analysis of the effects of pcr and α on the linearity and efficiency of the UCCF model is presented, establishing a robust theoretical foundation for achieving a balance between these two characteristics. Additionally, an examination of how pcr and α influence the load impedance design space is conducted, demonstrating that the UCCF mode not only offers a broader finite third-harmonic load impedance space but also expands the fundamental and second-harmonic load impedance design space. For practical validation, a PA with frequency of 2.05–2.65 GHz is designed based on CGH40010F. The test results show that S11 is less than −15 dB, the drain efficiency is 67.0–73.2%, and the output power is 40.1–41.0 dBm. The linearity is tested using a 5G NR (New Radio) signal with a bandwidth of 100 MHz and a peak-to-average power ratio of 8 dB at 2.35 GHz. The worst adjacent channel power ratio (ACPR) is −34.8 dBc without digital predistortion (DPD), and −57.8 dBc with DPD. An average output power (Pave) of around 32.4 dBm and an average DE (DEave) of 34.39% were obtained.

Novel signatures of radiation reaction in electron–laser sidescattering

In this article we investigate novel signatures of radiation reaction via the angular deflection of an electron beam colliding at 90 degrees with an intense laser pulse. Due to the radiation reaction effect, the electrons can be deflected towards the beam axis for plane wave backgrounds, which is not possible in the absence of radiation reaction effects. The magnitude and size of the deflection angle can be controlled by tailoring the laser pulse shapes. The effect is first derived analytically using the Landau–Lifshitz equation, which allows to determine the important scaling behavior with laser intensity and particle energy. We then move on to full scale 3D Monte Carlo simulations to verify the effect is observable with present day laser technology. We investigate the opportunities for an indirect observation of laser depletion in such side scattering scenarios.

SOME REMARKS ABOUT THE OBLIQUITY FACTOR USING IN THE KIRCHHOFF DIFFRACTION THEORY

In the framework of the work the description of sphere wave filed in the far observation region is discussed. The consideration is based on the decomposition of the wave field over the longitudinal and transverse spatial parameters of the problem in the direction of observation. It is shown that the approximation of a sphere wave by the flat field is correct only if the consideration is conducted in the limit of solid angle. The magnitude of the solid angle, which includes the area of flatness of the spherical wave, is determined using the so-called wave parameters corresponding to the observation area and the illuminated point. The wave field created by a small flat area is defined as a limit case of a superposition field generated by a system of point sources. It is shown that in an observation point the wave field of a small flat area can be characterized by the angle between the area normal and the vector indicting from the given area the observation point. The problem of description of a wave filed in the framework of a small flat aria is also discussed. A new method for deriving of the well-known obliquity factor of the Kirchhoff diffraction theory is suggested.

Analogue magnitude representation of angles and its relation to geometric expertise

The distance effect (comparing objects becomes easier with increasing differences in their magnitude) is observed in tasks ranging across domains, and its existence has been interpreted as evidence for analogue magnitude representation. Similarly, associations between response side and magnitude (faster left/right-sided responses to small/large objects, respectively) are observed across domains. We investigated the analogue processing of angles and the association between angle magnitude and response side in relation to geometric expertise. We compared the behavioural pattern of two groups—architects and controls—in a direct angle magnitude classification task (i.e., judge whether a presented angle was greater or less than 90°) and in an indirect task (i.e., judge whether an angle was drawn with a dashed or continuous line). We found a robust distance effect for reaction times and accuracy at the whole sample level and in each group separately. Architects revealed a smaller distance effect for accuracy than controls. This could be interpreted as an argument for a more precise analogue representation of angles in experts compared to non-experts. However, we did not find evidence for an association between angle magnitude and response side in any group.

The relationship between joint kinematic patterns during single-leg drop landing and perceived instability in individuals with chronic ankle instability

BackgroundPerceived instability is a primary symptom among individuals with chronic ankle instability. However, the relationship between joint kinematics during landing remains unclear. Therefore, we investigated the relationships between landing kinematics and perceived instability in individuals with chronic ankle instability. MethodsIn 32 individuals with chronic ankle instability, we recorded ankle, knee, and hip joint angles during a single-leg drop landing. Joint angle waveforms during 200 ms before and after initial contact were summarized into single values using two methods: peak joint angles and principal component scores via principal component analysis. Using Spearman's rank correlation coefficient (ρ), we examined the relationships of peak joint angles and principal component scores with the Cumberland Ankle Instability Tool score, with a lower score indicating a greater perceived instability (α = 0.05). FindingsThe second principal component scores of ankle angle in the horizontal and sagittal planes significantly correlated with the Cumberland Ankle Instability Tool score (Horizontal: ρ = 0.507, P = 0.003; Sagittal: ρ = −0.359, P = 0.044). These scores indicated the differences in the magnitude of angles before and after landing. Significant correlations indicated a greater perceived instability correlated with smaller internal rotation and plantarflexion before landing and smaller external rotation and dorsiflexion after landing. In contrast, no peak joint angles correlated with the Cumberland Ankle Instability Tool score (P > 0.05). InterpretationIn individuals with chronic ankle instability, ankle movements during landing associated with perceived instability may be a protective strategy before landing and potentially cause ankle instability after landing.

Postur Kifosis Berhubungan Dengan Gangguan Keseimbangan Postural Lanjut Usia Di Jebres Surakarta

The aging process in the elderly population can lead to changes in body posture, often resulting in kyphosis, which exacerbates postural balance disorders. This study aims to determine the relationship between kyphosis posture incidence and postural balance disorders among the elderly in Jebres, Surakarta. The research design employed was an observational analytic correlation with a cross-sectional design, utilizing purposive sampling techniques. The independent variable was kyphosis, while the dependent variable was balance disorders. The instruments used included the Unteberger test for assessing balance and the Occiput-to-Wall distance test for measuring kyphosis. Results from the study revealed that out of 67 respondents from a total population of 75 elderly individuals, 30 (44.77%) experienced kyphosis, with 23 (34.32%) presenting hyper kyphosis. Additionally, 53 (79.10%) respondents exhibited balance disorders, while 14 (20.89%) did not have kyphosis or balance disorders. Bivariate analysis using the Spearman rho test demonstrated a significant correlation between Balance Disorders and Kyphosis Posture, with a Sig (2-tailed) value of 0.001 and a correlation coefficient of 0.759. The relationship between these two variables was found to be unidirectional, indicating a significant association between the incidence of kyphosis posture and postural balance disorders in the elderly in Jebres, Surakarta. For future research, it is recommended to further explore the specific magnitude of kyphosis angles and their impact on postural balance disturbances