Comparison of the kinematics, repeatability, and reproducibility of five different multi-segment foot models

Background Multi-segment foot models (MFMs) for assessing three-dimensional segmental foot motions are calculated via various analytical methods. Although validation studies have already been conducted, we cannot compare their results because the experimental environments in previous studies were different from each other. This study aims to compare the kinematics, repeatability, and reproducibility of five MFMs in the same experimental conditions. Methods Eleven healthy males with a mean age of 26.5 years participated in this study. We created a merged 29-marker set including five MFMs: Oxford (OFM), modified Rizzoli (mRFM), DuPont (DFM), Milwaukee (MiFM), and modified Shriners Hospital for Children Greenville (mSHCG). Two operators applied the merged model to participants twice, and then we analysed two relative angles of three segments: shank-hindfoot (HF) and hindfoot-forefoot (FF). Coefficients of multiple correlation (CMC) and mean standard errors were used to assess repeatability and reproducibility, and statistical parametric mapping (SPM) of the t-value was employed to compare kinematics. Results HF varus/valgus of the MiFM and mSHCG models, which rotated the segment according to radiographic or goniometric measurements during the reference frame construction, were significantly more repeatable and reproducible, compared to other models. They showed significantly more dorsiflexed HF and plantarflexed FF due to their static offset angles. DFM and mSHCG showed a greater range of motion (ROM), and some models had significantly different FF points of peak angle. Conclusions Under the same conditions, rotating the segment according to the appropriate offset angle obtained from radiographic or goniometric measurement increased reliability, but all MFMs had clinically acceptable reliability compared to previous studies. Moreover, in some models, especially HF varus/valgus, there were differences in ROM and points of peak angle even with no statistical difference in SPM curves. Therefore, based on the results of this study, clinicians and researchers involved in the evaluation of foot and ankle dysfunction need an understanding of the specific features of each MFM to make accurate decisions.

Interrater Reliability of a Novel Goniometric Technique to Measure Scapular Protraction and Retraction

Importance: Scapular protraction and retraction are often essential for occupational performance; however, clinical assessment of these movements is uniquely challenging. Objective: To analyze the interrater reliability of a novel goniometric method to measure scapular protraction and retraction. Design: An observational, descriptive design was implemented to evaluate interrater reliability between two experienced occupational therapists who were also certified hand therapists. Setting: Academic institution. Participants: Convenience sample of graduate students (N = 80). Outcomes and Measures: The hypothesis, developed before study implementation, was that the technique would demonstrate clinically acceptable interrater reliability, defined as a standard error of measurement (SEM) <8°. Goniometric measurements of the scapula at rest, in maximal protraction, and in maximal retraction were independently obtained from each participant by each evaluator. The goniometer was aligned on the scapula using the superior angle as the axis of motion to measure the movement of the acromion relative to the frontal plane. The SEM was calculated in each position using the intraclass correlation coefficient values and the average of the standard deviations from the two raters. Results: The SEM values between the two evaluators for the resting, protracted, and retracted positions were 3.46°, 2.93°, and 2.74°, respectively. Conclusions and Relevance: The SEM between the two evaluators for each scapular position was <4°, suggesting that the technique may be clinically reliable. However, additional research regarding the reliability and validity of the technique is recommended. What This Article Adds: The findings of this study support the use of goniometry to measure scapular protraction and retraction in relation to occupational performance. The technique provides a way to quantify baseline scapular mobility and track progress.

Clinical evaluation of shoulder ROM in volleyball and handball players in youth categories

Aims. The aim of this study was to clarify whether volleyball and handball players, as representatives of the so-called overhead athletes, already have an increased ROM and specific local hypermobility in the shoulder joints in the junior categories. These changes are described by goniometric measurements and hypermobility tests according to Sachse and Beighton. The results are examined with respect to gender and sport specialization. Methods. Ninety-five subjects without previous shoulder joint injury aged 16 to 19 years, including 73 volleyball and handball players, were tested. The cohort included 33 men, 40 women, 34 handball players and 39 volleyball players. The control group consisted of 22 participants, including 11 men and 11 women. The majority (90.5%) of the study participants were right-hand dominant. Only 9.5% of the participants were left-handed. Measurements were taken with a goniometer with digital display and hypermobility tests according to Sachse and Beighton. Results. In a selected group of volleyball and handball players, the ROM of the shoulder joints of the dominant arm was significantly greater in three ways: into extension, horizontal adduction and external rotation. On the other hand, the ROM of their shoulder joints in internal rotation is smaller and the research group has significant hypermobility in the glenohumeral (scapulohumeral) joint compared to the control group. Our study showed that females compared to males playing volleyball and handball have a significantly higher degree of internal rotation of both dominant and non-dominant arms. No significant differences were found when comparing volleyball and handball players. The difference in ROM between the dominant and non-dominant arms of volleyball and handball players was shown in extension and external rotation.

Effects of rotation errors on goniometric measurements

Goniometric measurements are essential for the determination of many optical quantities, and quantifying the effects of errors in the rotation axes on these quantities is a complex task. In this paper, we show how a measurement model for a four-axis goniometric system can be developed to allow the effects of alignment and rotation errors to be included in the uncertainty of the measurement. We use three different computational methods to propagate the uncertainties due to several error sources through the model to the rotation angles and then to the measurement of bidirectional reflectance and integrated diffuse reflectance, a task that would otherwise be intractable. While all three methods give the same result, the GTC Python package is the simplest and intrinsically provides a full uncertainty budget, including all correlations between measurement parameters. We then demonstrate how the development of a measurement model and the use of GTC has improved our understanding of the system. As a consequence, taking advantage of negative correlations between measurements in different geometries allows us to minimise the total uncertainty in integrated diffuse reflectance, lowering the standard uncertainty from 0.0029 to 0.0015.

COMPARISON OF MUSCLE LENGTH IN DOMINANT VERSUS NON-DOMINANT LOWER EXTREMITY IN YOUNG ASYMPTOMATIC INDIVIDUALS

Muscle length is the length where maximum amount of force a muscle is able to produce. This length is determined by the joint angle that corresponds to the muscle. Understanding the optimal muscle length as well as its comparison between the extremities is very important as a part of examination in physiotherapy. Ranges that are obtained of muscle length helps therapist to recognize individuals with reduced flexibility. Identification and knowledge of muscle length has several role including; evaluation of pre-competition risk for injury, decreased flexibility as an predictor of muscle injury and guides in determining interventional strategy plus training program for an individual. Objectives: To compare muscle length of rectus femoris, hamstring’s, iliopsoas, gastrocnemius in dominant as well as non-dominant side of young asymptomatic individuals in the age group of 18 to 25 years. Method: Through standard goniometer muscle length data was obtained between dominant, non-dominant lower extremity. The methods of assessment used were; active knee extension (AKE) tests the hamstrings length, Thomas and modified Thomas test had been used to evaluate iliopsoas and rectus femoris while prone, figure-four position accompanied by dorsiflexion utilized for gastrocnemius. Result: Values were calculated using goniometric measurements through the group mean values. There is statistically significant variation between the muscle length of hamstring, rectus femoris, iliopsoas and gastrocnemius between the dominant and non-dominant side (p<0.05). Conclusion: Along with data about lower limb muscle length of asymptomatic individuals, we conclude notable difference in dominant to non-dominant extremities muscle length in individuals eighteen to twenty five year.

Repetitive and forceful movements of the hand as predictors of treatment for pain in the distal upper extremities

ObjectiveTo investigate repetitive movements and the use of hand force as causes of treatment for distal upper extremities musculoskeletal disordersMethodsA cohort of 202 747 workers in a pension health scheme from 2005 to 2017 in one of 17 jobs (eg, office work, carpentry, cleaning) was formed. Representative electro-goniometric measurements of wrist angular velocity as a measure for repetition and expert-rated use of hand force were used in a job exposure matrix (JEM). Job titles were retrieved from the Danish registers. Outcome was first treatment in the distal upper extremities. In a Poisson regression model, incidence rate ratios (IRRs) of treatment were adjusted for age, calendar-year, diagnosis of rheumatoid arthritis and arm fractures. In further analyses, wrist velocity or hand force was added.ResultsIn men, wrist velocity had an IRR of 1.48 (95% CI 1.15 to 1.91) when the highest exposure level was compared with the lowest but with no clear exposure-response pattern. The effect became insignificant when adjusted for hand force. Hand force had an IRR of 2.65 (95% CI 2.13 to 3.29) for the highest versus the lowest exposure with an exposure-response pattern, which remained after adjustment for wrist velocity. Among women, no increased risk was found for hand force, while wrist velocity showed a significantly protective association with treatment.ConclusionsIn men, occupational exposure to hand force more than doubled the risk of seeking treatment. The results for exposure to repetition were less clear. In women, we could not find any indications of an increased risk neither for force nor for repetition.

The Tuning of LIPSS Wettability during Laser Machining and through Post-Processing

In this work, we investigate the fabrication of stainless-steel substrates decorated with laser-induced periodic surface structures (LIPSS) of both hydrophilic and hydrophobic wettability through different post-processing manipulation. In carrying out these experiments, we have found that while a CO2-rich atmosphere during irradiation does not affect final wettability, residence in such an atmosphere after irradiation does indeed increase hydrophobicity. Contrarily, residence in a boiling water bath will instead lead to a hydrophilic surface. Further, our experiments show the importance of removing non-sintered nanoparticles and agglomerates after laser micromachining. If they are not removed, we demonstrate that the nanoparticle agglomerates themselves become hydrophobic, creating a Cassie air-trapping layer on the surface which presents with water contact angles of 180°. However, such a surface lacks robustness; the particles are removed with the contacting water. What is left behind are LIPSS which are integral to the surface and have largely been blocked from reacting with the surrounding atmosphere. The actual surface presents with a water contact angle of approximately 80°. Finally, we show that chemical reactions on these metallic surfaces decorated with only LIPSS are comparatively slower than the reactions on metals irradiated to have hierarchical roughness. This is shown to be an important consideration to achieve the highest degree of hydro-philicity/phobicity possible. For example, repeated contact with water from goniometric measurements over the first 30 days following laser micromachining is shown to reduce the ultimate wettability of the surface to approximately 65°, compared to 135° when the surface is left undisturbed for 30 days.

Quaternion Method of Calculating Angles while Measuring via Goniometric Precision Instrument System

The article is devoted to the topical problem: increasing accuracy and performance of angle measurements necessary in various branches of science and technology. One of the ways of increasing accuracy and performance of angle measurements is using modern algorithmic methods and mathematic devices for processing measurement information. Thus, in order to increase accuracy and speed of angle measurements on the example of the well-known goniometric precision instrument system (GPIS), it was offered quaternion calculation of angle values while performing goniometric measurements in the work. The efficiency of quaternion calculation is unquestioned as quaternions unlike other traditional methods (in particular matrix with the use of Euler angles, direction cosines) are presented only with four parameters describing angle positions of the objects and have only one connection equation unlike six equations for matrix methods, in particular for direction cosines. The suggested quaternion calculation is used in GPDS as general theoretic and information basis of contactless precision goniometric measurements in preliminary setting navigation sensitive elements (NSE), plane angles, pyramid prisms etc. The usage of the developed quaternion calculation enabled to increase accuracy by 0,25 (in 3 times) and measurement performance in 9 times (up to 6.5 sec.) in comparison with the famous ones. Applying quaternion calculation of angle values implies using a smaller RAM capacity of PC that increases performance of system work. Besides, a smaller amount of mathematic operations performed in quaternion way of calculating angles, except increasing performance, enables to decrease a rounding error in calculation results that is accumulated in multiple measurements and may reach great values. Thus, accuracy and performance of measurements increase.

Common Nettle (Urtica dioica L.) as an Active Filler of Natural Rubber Biocomposites

Common nettle (Urtíca Dióica L.), as a natural fibrous filler, may be part of the global trend of producing biocomposites with the addition of substances of plant origin. The aim of the work was to investigate and explain the effectiveness of common nettle as a source of active functional compounds for the modification of elastomer composites based on natural rubber. The conducted studies constitute a scientific novelty in the field of polymer technology, as there is no research on the physico-chemical characteristics of nettle bio-components and vulcanizates filled with them. Separation and mechanical modification of seeds, leaves, branches and roots of dried nettle were carried out. Characterization of the ground plant particles was performed using goniometric measurements (contact angle), Fourier transmission infrared spectroscopy (FTIR), themogravimetric analysis (TGA) and scanning electron microscopy (SEM). The obtained natural rubber composites with different bio-filler content were also tested in terms of rheological, static and dynamic mechanical properties, cross-linking density, color change and resistance to simulated aging processes. Composites with the addition of a filler obtained from nettle roots and stems showed the highest mechanical strength. For the sample containing leaves and branches, an increase in resistance to simulated ultraviolet and thermo-oxidative aging processes was observed. This phenomenon can be attributed to the activity of ingredients with high antioxidant potential contained in the plant.

NETWORK POSITIONING IN 5G ECOSYSTEM

Анализируются особенности построения и функционирования сети радиодоступа 5G, как экосистемы сетевого позиционирования устройств. В ходе анализа новых технологий радиоинтерфейса 5G, существенных с точки зрения задач геолокации, выявляются принципиальные возможности повышения точности определения местоположения за счетугломерных измерений. Проведенный анализ показывает роль сетевого позиционирования, как инструмента повышения эффективности функционирования радиостанций в составе сетей радиодоступа 5G за счет пространственной фильтрации радиосигналов при наличии и отсутствии прямой видимости. Проиллюстрированы возможности компенсации внутрисистемных помех в условиях сверхплотного распределения устройств за счет адаптивного диаграммообразования, реализованного путем предваритель -ного позиционирования радиостанций. In this article, we analyze new features of the construction and functioning of the 5G radio access network, as an ecosystem of network positioning of devices. During the analysis of new technologies of the 5G radio interface, which are significant from the point of view of geolocation, fundamental opportunities for improving the accuracy of location estimation through goniometric measurements are identified. The analysis shows the role of network positioning as a tool for increasing the efficiency of 5G networks radio stations due to the spatial filtering of radio signals in the presence and absence of line of sight. The possibilities of compensating for intra-system interference in the conditions of ultra-dense distribution of devices due to adaptive beamforming, which can be implemented through the preliminary positioning of radio stations, are illustrated.