Reliability of an isometric test for measuring the strength of the hip abductors and adductors / Confiabilidade de um teste isométrico para medir a força dos abdutores e adutores do quadril

This study aimed to measure the reliability of a test for measuring the strength and strength imbalance of the hip abductors and adductors, using isokinetic equipment adapted for isometric testing. Thirteen healthy, physically active male individuals took part in the research. Two unilateral isometric tests were undertaken using a load cell attached to an adapted abductor bench machine: a hip abduction test and hip adduction test. Tests consisted of two maximum voluntary isometric contractions made for six seconds with a break of one minute between each. The following dynamic variables were measured: maximum force, mean force, rate of force development for each limb (right and left), and the existence of asymmetries between the limbs. For statistical analysis, the t-test, intraclass correlation coefficient (ICC), and standard error of measurement (SEM) were applied. Results: The methodology utilized for the evaluation of the hip abductors and adductors did not show reliability in most of the parameters researched, with the ICC neither sufficient or low, and the retest performance higher than the test (p < 0.05). The applied test was not reliable for assessing strength and strength imbalances of hip abductors and adductors in most of the parameters investigated. These results indicate that the hip joints, more precisely, the abductor and adductor muscles, are complex structures to be assessed. They need to be previously familiarized with the proposed exercise, as their performance does not occur habitually. It is recommended to develop new tests in order to measure hip abduction and adduction strength adding a prior familiarization procedure

O presente estudo teve como objetivo avaliar a confiabilidade de um teste para avaliação da força e desequilíbrios de força de abdutores e adutores de quadril utilizando um equipamento isoinercial adaptado para isometria. Participaram do estudo 13 sujeitos saudáveis, do sexo masculino, fisicamente ativos. Foram realizados dois testes isométricos unilaterais utilizando uma célula de carga fixada em um banco abdutor adaptado: teste de Abdução de Quadril e Teste de Adução de Quadril. Os testes consistiram em duas contrações isométricas voluntárias máximas de seis segundos de duração com intervalo de um minuto entre elas. As seguintes variáveis dinâmicas foram avaliadas: Força Máxima, Força Média, Taxa de Produção de Força, para cada membro (direito e esquerdo), e a existência de assimetrias entre membros. Para análise estatística foram realizados teste t, coeficiente de correlação intraclasse (CCI) e erro padrão de medida. Resultados: A metodologia empregada para avaliação de adutores e abdutores de quadril não se mostrou confiável na maioria dos parâmetros investigados, com valores de CCI não significativos ou baixos, e o desempenho no reteste foi superior ao teste (p<0,05). O teste empregado não se mostrou confiável para avaliação da força e desequilíbrios de força de abdutores e adutores do quadril na maioria dos parâmetros investigados . Esses resultados demonstram que a articulação do quadril, mais precisamente os músculos abdutores e adutores, são estruturas complexas de se avaliarem, necessitando de uma familiarização prévia com o exercício proposto, por não serem movimentos realizados habitualmente. Recomenda-se novos testes para avaliação da força de adução e abdução de quadril adicionando um procedimento de familiarização prévio.

Development of an Al-load-cell-based wireless ringer's solution monitoring and alarm system: insight into vibrational error correction

In this study, we developed an aluminum-load-cell-based wireless Ringer's solution monitoring and alarm (WRMA) system. The Al load cell was designed with a rectangular shape, and the load was concentrated in the lower beam part of the load cell because of the anisotropic thickness. From the static analysis, we identifi ed the appropriate location for a Wheatstone bridge circuit consisting of four strain gauges. In addition, the modal and harmonic analyses showed that the vibrational frequencies of the hospital environment do not seriously interfere with the output voltage of the Al load cell. However, random vibrations generated by the movement of the WRMA system on various surfaces severely increase the standard deviation of the measured solution weight by ± 10 g or more. Such vibrational error is too large because the average weight of Ringer's solution is 30–40 g at the time of replacing Ringer's solution. Thus, this error could be confusing for nurses and result in mistakes in the timely replacement of the Ringer's solution. However, the standard deviation of the measured weight was dramatically reduced to ± 3 g or less by using the vibration correction algorithm developed in the present study.

Desenvolvimento de lisímetros de pesagem na cultura do café / Development weighing lysimeters for coffee culture

O conhecimento das necessidades hídricas do cafeeiro é fator preponderante para o uso racional da irrigação. Diante disso, objetivou-se com esse trabalho desenvolver lisímetros de pesagem para a cultura do café por meio de sua construção, montagem, automação e calibração. Para isso, foram construídos três lisímetros com formatos e dimensões diferentes, com capacidades volumétricas de 0,941; 2,565 e 6,444 m3 . Para obtenção das massas dos lisímetros foram utilizadas quatro células de carga, por cada equipamento. A drenagem dos lisímetros foi mensurada por um pluviômetro de báscula instalado na parte inferior dos mesmos. As informações das células de carga e dos pluviômetros foram armazenadas automaticamente por um datalogger instalado a 3 m dos lisímetros. As paredes externas e os poços de visita foram construídos em concreto armado. As mudas de café plantadas em cada equipamento, bem como as demais da área foram irrigadas e fertirrigadas por gotejamento. A metodologia empregada na construção, montagem, automação e calibração dos lisímetros de pesagem é tecnicamente adequada, obtendo-se coeficiente de determinação superior a 99,96% na equação de calibração e erro padrão inferior a 0,66 mm. O uso de pluviômetros de báscula em substituição dos tradicionais recipientes para armazenamento da água drenada pelos lisímetros foi adequado e confiável. O uso da fibra de vidro na construção das caixas dos lisímetros em substituição da chapa de aço-carbono é viável.

Knowledge of water demand in coffee is a key factor for the rational use of irrigation. Therefore, this study evaluated the construction, assembly, automation and calibration of weighing lysimeters to determine the water demand of coffee plantations. Three lysimeters were built with different formats and dimensions, with volume capacities of 0.941, 2.565 and 6.444 m3 . The masses of the lysimeters were measured with four load cells per equipment. Drainage of the lysimeters was measured by tipping bucket rain gauges installed under each lysimeter. Readings of the load cells and of the tipping bucket gauges were automatically stored in a datalogger installed to 3 m the lysimeters. The external walls and the checking wells were made of concrete. The coffee seedlings planted in each equipment, as well as all others of plantations, were drip irrigated and ferti-irrigated. It can be concluded that the methodology used for construction, automation and calibration of the weighing lysimeters was technically adequate, with determination coefficient above 99.96% for the calibration equation and standard error below 0.66 mm. The use of tipping bucket gauges instead of the usual recipients for storage of drainage of water drained by the lysimeters was adequate and reliable. The use of glass fiber for the inner walls of the lysimeters instead of the steel sheets was a viable option.

Quantitative Evaluation of Median Nerve Motor Function in Carpal Tunnel Syndrome Using Load Cell : Correlation with Clinical, Electrodiagnostic, and Ultrasonographic Findings

OBJECTIVE: Major complaints of carpal tunnel syndrome (CTS) are sensory components. However, motor deficit also impedes functional status of hand. Contrary to evaluation of sensory function, the objective, quantitative evaluation of median nerve motor function is not easy. The motor function of median was evaluated quantitatively using load cell and its correlation with findings of electrodiagnostic study (EDS) was evaluated. METHODS: Objective motor function of median nerve was evaluated by load cell and personal computer-based measurement system. All of the measurement was done in patients diagnosed as having idiopathic CTS by clinical features and EDS findings. The strength of thumb abduction and index finger flexion was measured in each hand three times, and the average value was used to calculate thumb index ratio (TIR). The correlation of TIR with clinical, EDS, and ultrasonographic findings were evaluated. RESULTS: The TIR was evaluated in 67 patients (119 hands). There were 14 males and 53 females, mean age were 57.6 years (range 28 to 81). The higher preoperative nerve conductive studies grade of the patients, the lower TIR was observed [p<0.001, analysis of variance (ANOVA)]. TIR of cases with thenar atrophy were significantly lower than those without (p<0.001, t-test). TIR were significantly lower in patients with severe median nerve swelling in ultrasonography (p=0.042, ANOVA). CONCLUSION: Measurements of median nerve motor function using load cell is a valuable evaluation tool in CTS. It might be helpful in detecting subclinical motor dysfunction before muscle atrophy develops.

Tomato (Lycopersicon esculentum P. Miller) compression due to "K" wood box closing / Compressão de tomate (Lycopersicon esculentum P. Miller) em função do fechamento da caixa de madeira tipo "K"

Wood boxes kind "k" are the most used in table tomato (Lycopersicon esculentum P. Miller) commercialization in Brazil. Due to the fruit accommodation process that occurs during the transport from the production place to the commercialization point, producers fill tomato boxes a little bit over its physical capacity, and they close it with wood strips fixed with nails. In order to prevent strips from cracking, it is common to keep them inside water before using, to increase flexibility. When boxes are opened, many fruits are cracked or kneaded in a significant part of their total area, and normally they are thrown away. The purpose of this paper was to quantify the compression tomato fruits are exposed to in consequence of the "k" box fill / closing system. For this study a special instrumented box was constructed with a scales plate located at the bottom, with a hydraulic load cell instrumented in the box. This instrument was then used to study the compression of fruits as the box is filled and the compression increase caused by the addition of its wooden lid. The "k" box closing system caused an initial compression increase 3.5 times the compression of the open tomato box, and during time as the fruits are substantially deformed. This compression was reduced two about two times de initial reference value. The consequence of this observed fruit compression is compatible with the fruit deformations and even cracks observed in the market, which are known to be relevant post harvest losses causes in the Brazilian tomato handling industry.

Caixas de madeira do tipo "K" são as mais utilizadas na comercialização de tomate (Lycopersicon esculentum P. Miller) de mesa no Brasil. Em razão do processo de acomodação dos frutos que ocorre durante o transporte desde o local de produção até o local de comercialização, os produtores enchem a caixa de tomate um pouco acima de sua capacidade física e a fecham com ripas de madeira e pregos. Para evitar que as ripas rachem, é comum mantê-las imersas em água antes do fechamento, para que fiquem mais flexíveis. Quando as embalagens são abertas, muitos frutos estão rachados ou amassados em parte significativa de sua área e, normalmente, são descartados. Para este estudo, construiu-se uma embalagem cujo fundo é uma balança, com uma célula de carga hidráulica acomodada no fundo da caixa. Desse modo, a pressão que os frutos sofreram no interior da caixa com e sem o fechamento da tampa foi registrada ao longo do tempo, com auxílio de um tubo manométrico. O fechamento da caixa aumentou, inicialmente, em 3,5 vezes a compressão e depois, com a deformação plástica dos frutos, a compressão diminuiu para cerca de duas vezes em relação à compressão observada na caixa aberta. Portanto, as pressões observadas no fechamento da caixa comprimem os frutos de tomate, causando amassamento e até mesmo rachaduras. Estas injúrias têm sido observadas frequentemente na pós-colheita deste e outros produtos e são causas primárias de perdas consideráveis.

Diseño y fabricación de una celda de carga para mediciones fisiológicas en distracción alveolar / Design and manufacturing of a load-cell for physiological measuring in alveolar distraction

Un factor de vital importancia para el diseño mecánico de distractor osteogénico alveolar es el conocimiento de las cargas fisiológicas para la simulación computacional, existe muy poca información o trabajos previos sobre este tema. Para obtener estas cargas, ha sido desarrollada una celda de carga constituida de una lámina de acero inoxidable en voladizo instrumentada con galgas extensométricas, la cual ha sido empotrada en una férula como la usada en tratamientos de ortodoncias. Luego de calibrar la celda de cargas fisiológicas, se realizó un ensayo in vivo sobre un paciente parcialmente edéntulo del maxilar inferior, obteniéndose registros digitales de cargas para diferentes condiciones de protrusión de la lengua, retracción del labio inferior y la combinación de ambas.

A key aspect involved in the mechanical design of alveolar distractor is the accurate evaluation of physiological loading for computer simulation. Very few information and previous work are available about this subject. A stainless steel load cell having strain gauges has been developed and manufactured. This cell was attached to a splint, like those used in orthodontia. The load cell was calibrated and then an “in vivo” test was carried out on a partially-edentulous patient. Digital registers of load were obtained for three cases: tongue protrusion, lower lips retraction and a combination of both.

Intraoperative Measurement of Femorotibial Contact Pressure in Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: A new method has been devised to determine contact pressures in prosthetic components. A real time analysis of the contact pressure distribution could help fine tuned implant positioning and ligament balancing during Total Knee Arthroplasty. MATERIALS AND METHODS: Posterior cruciate reserving type procedures were done with externally rotated femoral cut. Femorotibial contact pressure was measured in four compartments in both flexion and extension position. A LOAD CELL located beneath the tibial plate changes the contact pressure into electric signal and DP-41S transformed the electric sign into the pressure unit. Adjunctive fine-tuning operation was done to approximate the equilibrium among the four compartments of the tibial plate. RESULTS: Femorotibial contact pressure were distributed between 17.1 N (Newton) to 33.4 N (average 23.6 N). A peak contact pressure was exhibited in the anteromedial compartment in extended knee and in the posterolateral compartment in flexed knee. CONCLUSION: A LOAD CELL electronic transducer technique was introduced. This method was tried to get the balanced equilibrium of contact pressure between Femorotibial components during TKA.