Journal articles: 'Dynamometers'

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Flood-Joy, Maureen, and Virgil Mathiowetz. "Grip-Strength Measurement: A Comparison of Three Jamar Dynamometers." Occupational Therapy Journal of Research 7, no. 4 (July 1987): 235–43. http://dx.doi.org/10.1177/153944928700700405.

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These two studies evaluated whether three types of Jamar dynamometers measured equivalently. In study A, 26 subjects were tested on 2 types; in study B, 30 subjects were tested on 3 types. Both studies found significant differences between and among the dynamometers. Therapists can no longer assume that all versions of the Jamar dynamometer measure equivalently, and the differences should be taken into account when using normative data and when assessing treatment effectiveness. In the latter case, the same dynamometer must be used for pre- and posttesting.

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P, Mafi, Mafi R, Hindocha S, Griffin M, and Khan W. "A Systematic Review of Dynamometry and its Role in Hand Trauma Assessment." Open Orthopaedics Journal 6, no. 1 (February 23, 2012): 95–102. http://dx.doi.org/10.2174/1874325001206010095.

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The dynamometer was developed by American neurologists and came into general use in the late 19th century. It is still used in various ways as a diagnostic and prognostic tool in clinical settings. In this systematic review we assessed in detail the different uses of dynamometry, its reliability, different dynamometers used and the influence of rater experience by bringing together and evaluating all published literature in this field. It was found that dynamometry is applied in a wide range of medical conditions. Furthermore, the great majority of studies reported acceptable to high reliability of dynamometry. Jamar mechanical dynamometer was used most often in the studies reviewed. There were mixed results concerning the effect of rater experience. The factors influencing the results of dynamometry were identified as age, gender, body weight, grip strength, BMI, non/dominant hand, assessing upper/lower limbs, rater and patient’s strength and the distance from the joint where the dynamometer is placed. This review provides an understanding of the relevance and significance of dynamometry which should serve as a starting point to guide its use in hand trauma assessment. On the basis of our findings, we suggest that hand dynamometry has a great potential, and could be used more often in clinical practice.

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Turusheva, Anna V., Elena V. Frolova, and Jean-Marie Degryse. "Comparison of measurement results are obtained with dynamometers DK-50 and JAMAR® Plus." Russian Family Doctor 22, no. 1 (March 15, 2018): 12–17. http://dx.doi.org/10.17816/rfd2018112-17.

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Introduction. Grip strength is a reflection not only of the strength of the hands, but also the strength of the muscles of the whole body, the functional capabilities of the body and an important diagnostic marker of the overall health of a person. The aim of this work was to compare the measurements obtained with the DK-50 and JAMAR® Plus digital handheld dynamometers.Methods. A convenience sample was used of 94 health participants, men and women, aged from 15 to 65 years old. Grip strength of a dominant hand was conducted using a carpal mechanical dynamometer DK-50 (Nizhni Tagil, Russian Federation) and JAMAR® Plus digital handheld dynamometer. The simple Pearson correlation test, linear regression method and the procedure of Bland and Altman were used to estimate difference between an average value of results of measurements of grip strength (AGS) and maximum measurement of grip strength (MGS) of the dominant hand of two dynamometers.Results. The grip strength using JAMAR® Plus dynamometer was higher than with the DK-50 dynamometer by 5.6 ± 4.2 kg for the average grip strength (AGS) and by 6.7 ± 4.3 kg for the maximum grip strength (MGS). The formulas for transferring the data of the car dynamometry of the DK-50 dynamometer to the values obtained from the JAMAR® Plus dynamometer are calculated: AGS JAMAR® Plus == 1,7874 + 1,1208 × AGS DK-50 and MGS JAMAR® Plus = 1.7667 + 1, 1275 × MGS DK-50.Conclusion. For avoiding errors in the interpretation of the results from different studies, it is necessary to take into account which type of dynamometer was used. The resulting formulas (AGS JAMAR® Plus == 1,7874 + 1,1208 × AGS DK50 and MGS JAMAR® Plus = 1,7667 + 1,1275 × MGS DK50) can be used to correct the data of the dynamometer DK-50 for value of JAMAR® Plus dynamometer and to compare the results of Russian studies with data from foreign studies organized using JAMAR® Plus dynamometers. (For citation: Turusheva AV, Frolova EV, Degryse J-M. Comparison of measurement results are obtained with dynamometers DK-50 and JAMAR® Plus. Russian Family Doctor. 2018;22(1):12-17. doi 10.17816/RFD2018112-17).

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French, M., and A. Stark. "CHASSIS DYNAMOMETERS." Experimental Techniques 24, no. 4 (July 2000): 45–46. http://dx.doi.org/10.1111/j.1747-1567.2000.tb00926.x.

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Fofanov, O. N., T. Yu Loskutova, and G. M. Tkachenko. "Universal dynamometers." Measurement Techniques 32, no. 8 (August 1989): 801–3. http://dx.doi.org/10.1007/bf02110500.

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Raine, J. K., and P. G. Hodgson. "Computer Simulation of a Variable Fill Hydraulic Dynamometer; Part 1: Torque Absorption Theory and the Influence of Working Compartment Geometry on Performance." Proceedings of the Institution of Mechanical Engineers, Part C: Mechanical Engineering Science 205, no. 3 (May 1991): 155–63. http://dx.doi.org/10.1243/pime_proc_1991_205_106_02.

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A mathematical model of the steady state torque absorption process in variable fill hydraulic dynamometers is described. This is the initial part of a general model that has been developed to simulate the dynamic behaviour of Froude-type dynamometers under open-loop control and of an engine/dynamometer system under various closed-loop control modes. In this paper, the equations for steady state torque, energy dissipation, fluid vortex pressure in the working compartment and water outflow from the dynamometer are presented. Predictions by the model for the special case of characteristic running full torque absorption performance are compared with experimental test bed results for different working compartment geometries. Effects of vane angle and working fluid properties on maximum torque capability are examined. Subsequent parts of this paper will address the dynamic variable fill simulation.

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Svens, Birgit, and Hoe Lee. "Intra- and inter-instrument reliability of Grip-Strength Measurements: GripTrack™ and Jamar® hand dynamometers." British Journal of Hand Therapy 10, no. 2 (June 2005): 47–55. http://dx.doi.org/10.1177/175899830501000202.

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The purpose of this research was to compare the computer-connected GripTrack dynamometer and the manual Jamar dynamometer to determine the intra- and inter-instrument reliability. Using a repeated-measures design the instruments were calibrated three times. Forty-six uninjured female health workers (mean age 29.7 years) performed three consecutive grip strength trials per hand and per instrument with the handle bar in the second position, alternating which dynamometer was used first. Intra-instrument reliability and concurrent validity were tested using certified standard weights. Both the Jamar dynamometer and GripTrack dynamometer demonstrated concurrent validity with certified standard weights (Jamar r = 1.0, GripTrack dynamometer r ≥ 0.9994). While inter-instrument reliability was good, starting with the Jamar dynamometer as the first instrument (ICC 0.80 to 0.83), and excellent, starting with the GripTrack dynamometer (ICC 0.94 to 0.95), the Bland and Altman method of analysing the differences between the two instruments’ grip strength readings revealed instrument bias. The large spread of limits of agreement from –2.37 kg to 7.87 kg (± 2 SD from the mean 2.75 kg) suggests variation in readings of up to 10.24 kg. While both dynamometers retain adequate calibration, the human interfaces are sufficiently different to cause large differences in readings between the dynamometers, making them non-interchangeable.

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Plint, M. A., and A. J. Martyr. "Technical Note: Some limitations of the chassis dynamometer in vehicle simulation." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 215, no. 3 (March 1, 2001): 431–37. http://dx.doi.org/10.1243/0954407011525647.

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The chassis dynamometer is the standard tool for legislatively prescribed emission tests. For emission testing and many other vehicle test purposes the dynamic response is an adequate approximation to ‘on road’ conditions. This is not necessarily true if the requirement is to study vehicle driveline dynamics. The present analysis arose from two quite separate requirements to study driveline oscillations and ‘judder’ using chassis dynamometers of the same eVective inertia as the vehicle. During the studies by the authors it became clear that the dynamics of the vehicle-dynamometer combination diVer in important respects from those of a vehicle on the road. As the eVective inertia of the dynamometer falls the natural frequency of the engine-driveline-vehicle system rises while the oscillatory energy imparted to the vehicle falls rapidly. For reasonably accurate simulation of driveline vibration the roll inertia should be some five times that of the vehicle. It is shown that electrical simulation of inertia, as employed in most modern chassis dynamometers, is unsatisfactory where oscillatory phenomena are being studied.

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Spengler, Dan M., and Gunnar B. J. Andersson. "Dynamometers and Exaggeration." Back Letter 5, no. 4 (February 1991): 7. http://dx.doi.org/10.1097/00130561-199102000-00009.

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Sunde, Douglas. "Accuracy of dynamometers." Journal of Hand Surgery 18, no. 1 (January 1993): 171. http://dx.doi.org/10.1016/0363-5023(93)90279-c.

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Abe, Takashi, Jeremy P. Loenneke, Robert S. Thiebaud, and Mark Loftin. "The Bigger the Hand, the Bigger the Difference? Implications for Testing Strength With 2 Popular Handgrip Dynamometers." Journal of Sport Rehabilitation 28, no. 3 (March 1, 2019): 278–82. http://dx.doi.org/10.1123/jsr.2017-0189.

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Context: Studies developed the frail elderly handgrip strength (HGS) diagnostic criteria using multiple types of handgrip dynamometers. If different handgrip dynamometers report different values, then this would have the potential to misclassify people into the wrong diagnostic category. Objective: To examine the characteristics of HGS measured by 2 standard handgrip dynamometers and to investigate the influence of hand size on HGS. Setting: University research laboratory. Participants: A total of 87 young and middle-aged adults between the ages of 20 and 60 years participated in this study. Main Outcome Measures: Standard methods of HGS measurements were used for hydraulic and Smedley spring-type dynamometers, although the participants were instructed to maintain an upright standing position in both tests. Results: Test–retest reliability of hydraulic and Smedley dynamometers provided comparable results to that observed with previous studies. However, the difference in HGS between the 2 dynamometers (Hydraulic–Smedley difference) was positively associated (r = .670, P < .001) with the mean of the 2 dynamometers. The participants who had relatively low HGS (at least <35 kg) produced similar HGS values when the 2 dynamometers were compared, whereas persons who had relatively higher HGS (at least >45 kg) produced greater strength values with the hydraulic compared with the Smedley. The hand and palm lengths were weakly correlated (r = .349 and r = .358, respectively, both Ps < .001) with the difference in HGS between the 2 dynamometers. Conclusions: Test–retest reliability of hydraulic and Smedley dynamometers provides comparable results to previous studies. However, the difference in HGS between the 2 dynamometers was positively associated with the mean of the 2 dynamometers. This Hydraulic–Smedley difference would not affect persons who have relatively low HGS (at least <35 kg), while when HGS is relatively high, the comparison between dynamometers should be done with caution.

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PIETRAS, Dariusz, and Piotr ŚWIĄTEK. "The selection of calibration parameters of a 1.3 Multijet engine management system in the aspect of engine performance and exhaust gas compositon." Combustion Engines 133, no. 2 (May 1, 2008): 36–43. http://dx.doi.org/10.19206/ce-117245.

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The objective of passenger car engine tests performed on engine dynamometers, apart from the aspects of operation and durability, is the development in the range of suitable selection of parameters controlling the engine operation. The final selection of these parameters and their verification take place in the course of the tests accomplished with the use of engine dynamometers. The paper presents and discusses the effects of selected calibrations of 1.3 Multijet engine management system on the parameters of its operation and the composition of the exhaust gases. The accomplishment of that subject-matter resolved itself into testing work on an engine dynamometer to verify selected calibrations of the engine management system, developed on the basis of the experience of the authors acquired during their research performed earlier. Bearing in mind that the engine as the object of the testing serves as a power unit in a passenger car, it was assumed that the selection of the operational points of the engine, for which the tests should be performed on an engine dynamometer, should result from the mapping of the engine operation in the area of selected, characteristic phases of the driving test on a chassis dynamometer. The presented test results, exhaust gas composition and smokiness, as well as the overall efficiency for individual calibrations of the management system were put together in a form of bar graphs.

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Chamorro, Claudio, Susan Armijo-Olivo, Carlos De la Fuente, Javiera Fuentes, and Luis Javier Chirosa. "Absolute reliability and concurrent validity of hand held dynamometry and isokinetic dynamometry in the hip, knee and ankle joint: systematic review and meta-analysis." Open Medicine 12, no. 1 (October 17, 2017): 359–75. http://dx.doi.org/10.1515/med-2017-0052.

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AbstractThe purpose of the study is to establish absolute reliability and concurrent validity between hand-held dynamometers (HHDs) and isokinetic dynamometers (IDs) in lower extremity peak torque assessment. Medline, Embase, CINAHL databases were searched for studies related to psychometric properties in muscle dynamometry. Studies considering standard error of measurement SEM (%) or limit of agreement LOA (%) expressed as percentage of the mean, were considered to establish absolute reliability while studies using intra-class correlation coefficient (ICC) were considered to establish concurrent validity between dynamometers. In total, 17 studies were included in the meta-analysis. The COSMIN checklist classified them between fair and poor. Using HHDs, knee extension LOA (%) was 33.59%, 95% confidence interval (CI) 23.91 to 43.26 and ankle plantar flexion LOA (%) was 48.87%, CI 35.19 to 62.56. Using IDs, hip adduction and extension; knee flexion and extension; and ankle dorsiflexion showed LOA (%) under 15%. Lower hip, knee, and ankle LOA (%) were obtained using an ID compared to HHD. ICC between devices ranged between 0.62, CI (0.37 to 0.87) for ankle dorsiflexion to 0.94, IC (0.91to 0.98) for hip adduction. Very high correlation were found for hip adductors and hip flexors and moderate correlations for knee flexors/extensors and ankle plantar/dorsiflexors.

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Kolimechkov, Stefan, Jose Castro-Piñero, Lubomir Petrov, and Albena Alexandrova. "The effect of elbow position on the handgrip strength test in children: validity and reliability of TKK 5101 and DynX dynamometers." Pedagogy of Physical Culture and Sports 24, no. 5 (October 30, 2020): 240–47. http://dx.doi.org/10.15561/26649837.2020.0504.

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Background and Study Aim: One of the most widely applied methods to assess upper-body strength in children and adolescents is the handgrip strength test. While in adolescents it has been determined which elbow position, and which type of dynamometer are most appropriate for achieving the maximal grip strength, in children is still not clear. Therefore, the purpose of this study was to investigate whether elbow position and the type of dynamometer affect the handgrip strength in children. Material and Methods: Grip strength was measured by TKK and DynX dynamometers, and their validity and reliability were also analysed. A total of 60 children, 6 to 11 years old, participated in this study, and performed the handgrip strength test with their elbow extended and flexed at 90°. Results: While using the TKK dynamometer, grip strength was significantly higher when the test was performed with elbow extended, in contrast to those obtained with elbow flexed (14.58±3.04 kg vs 12.97±2.99 kg, p<0.001 for right, and 14.25±3.05 kg vs 12.61±2.99 kg, p<0.001 for left hand). Likewise, when using the DynX dynamometer, the difference between the two elbow positions was smaller but still significant (13.84±3.22 kg vs 13.35±3.01 kg, p=0.035 for right, and 13.35±2.95 kg vs 12.77±2.96 kg, p=0.003 for left hand). Conclusions: Both dynamometers provided sufficient results in terms of their reliability and the TKK dynamometer showed to be more valid. Performing the handgrip strength test with elbow extended appears to be the most appropriate position in order to obtain maximal results in children.

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Neptune, Rick, and Maury L. Hull. "A New Electromechanical Ski Binding with Release Sensitivity to Torsion and Bending Moments Transmitted by the Leg." International Journal of Sport Biomechanics 8, no. 4 (November 1992): 331–49. http://dx.doi.org/10.1123/ijsb.8.4.331.

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This paper describes the design of a new electromechanical ski binding whereby release in both twist and forward bending is controlled electronically and the release level in twist is modulated electronically based on the neural stimulation of muscles in the quadriceps group. To provide signals for controlling release in the two modes, the binding incorporates two dynamometers. Each dynamometer measures loads that have been shown to correlate strongly (r2>0.90) to torsional and bending moments at the lower leg injury sites. Although the binding consists of both a toepiece and heelpiece, the toepiece does not permit release of the boot from the ski in the twist mode but rather serves as one of the dynamometers. Consequently the heelpiece was designed to provide the release function in both modes. Release is realized by a low-force solenoid that actuates a multilink trigger mechanism. To prove feasibility, a prototype was constructed and evaluated.

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Totis, Giovanni, Zoltan Dombovari, and Marco Sortino. "Upgraded Kalman Filtering of Cutting Forces in Milling." Sensors 20, no. 18 (September 21, 2020): 5397. http://dx.doi.org/10.3390/s20185397.

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Advanced piezoelectric dynamometers with a wide frequency bandwidth are required for cutting force measurement in high-speed milling and micromilling applications. In many applications, the signal bandwidth is limited by the dynamic response of the mechanical system, thus compensation techniques are necessary. The most effective compensation techniques for a full 3D force correction require an accurate and complex identification phase. Extended Kalman filtering is a better alternative for input force estimation in the presence of unknown dynamic disturbances. The maximum bandwidth that can be currently achievable by Kalman filtering is approximately 2 kHz, due to crosstalk disturbances and complex dynamometer’s dynamics. In this work, a novel upgraded Kalman filter based on a more general model of dynamometer dynamics is conceived, by also taking into account the influence of the force application point. By so doing, it was possible to extend the frequency bandwidth of the device up to more than 5 kHz along the main directions and up to more than 3 kHz along the transverse directions, outperforming state-of-the-art methods based on Kalman filtering.

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Dubov, B. S., G. I. P'yanzin, N. M. Kopytin, and V. N. Samsonova. "Metrological investigation of tensoresistor dynamometers." Measurement Techniques 32, no. 1 (January 1989): 57–60. http://dx.doi.org/10.1007/bf00863640.

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Barbato, Giulio, and Fiorenzo Franceschini. "Performance indicators for multicomponent dynamometers." Measurement 13, no. 4 (July 1994): 297–306. http://dx.doi.org/10.1016/0263-2241(94)90054-x.

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Nikodelis, Thomas, Stratos Savvoulidis, Petros Athanasakis, Christos Chalitsios, and Theodoros Loizidis. "Comparative Study of Validity and Reliability of Two Handgrip Dynamometers: K-Force Grip and Jamar." Biomechanics 1, no. 1 (March 25, 2021): 73–82. http://dx.doi.org/10.3390/biomechanics1010006.

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Background: Handheld dynamometers are used for diagnosis and rehabilitation at several pathologies. Grip force is essential for a person’s quality of life. Most dynamometers are not equipped with rehabilitation or training protocols, although the bibliography highlights this need. Objective: To compare the validity and reliability of Jamar and K-Force Grip dynamometers in patients with shoulder impingement syndrome and healthy people. Methods: Concurrent validity was assessed using known weights. Forty-four (44) patients and 69 healthy adults performed three maximum repetitions in random order with each hand, at each instrument. Reliability was evaluated using ICCs for each instrument separately, and between the two instruments. The differences between the two dynamometers were evaluated using repeated t-tests. Results: Concurrent validity of the two instruments did not reveal fix or proportional bias. Analyses for reliability yield high correlation coefficients for both groups with the lower one being between the two instruments r = 0.90, p < 0.05, (0.72–0.91) for the healthy group. T-tests showed that all participants had lower force values when using the K-Force Grip (p < 0.05). Conclusion: Both dynamometers were reliable in measuring hand grip strength for both groups. K-Force Grip was reliable and valid with respect to Jamar that was used as a benchmark. The different handle dimensions between the two dynamometers may be the reason for the different force values.

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Traum, Matthew J., and Hope L. Weiss. "Tiny Tesla Turbine Analytical Performance Validation Via Dynamic Dynamometry." E3S Web of Conferences 113 (2019): 03024. http://dx.doi.org/10.1051/e3sconf/201911303024.

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Tesla turbines produce power at high rotation rate and low torque relative to other prime movers. At a tiny scale, this attribute renders Tesla turbines poorly matched to dynamometers designed to characterize electricand gasoline-powered radio-controlled vehicles and kit cars. Techniques are needed to enable Tesla turbine design and performance evaluation. An analytical modelling approach was recently developed by Carey, and a complimentary experimental technique, dynamic dynamometry, can determine Tesla turbine power curves without a dynamometer. This paper mutually validates these approaches by comparing them to each other using results from a 3D printed 4-disk tiny Tesla turbine with characteristic disk inner/outer diameter of 11.54 ± 0.01 mm and 24.85 ± 0.01 mm respectively. The Carey model predicts maximum power output of 0.077 ± 0.015 W, and dynamic dynamometry predicts 0.122 ± 0.008 W, a 36.9% difference. Bounding assumptions were used and more accurate parameter measurements will drive these values closer together. Peculiarities of tiny Tesla turbine operation are also described, including the discovery that turbine spin-down rotational velocity is not linear with time. This phenomenon is likely caused by fluid boundary layer shear between the housing and outer disks. It is not observed in larger Tesla turbines, suggesting a speed, size and/or disk count threshold at which this phenomenon introduces non-trivial parasitic reduction in performance.

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Korkmaz, Emrullah, Bekir Bediz, B. Arda Gozen, and O. Burak Ozdoganlar. "Dynamic characterization of multi-axis dynamometers." Precision Engineering 38, no. 1 (January 2014): 148–61. http://dx.doi.org/10.1016/j.precisioneng.2013.08.006.

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Jones, Daniel W., Steven F. Figoni, Aaron Parker, and Michelle Obispo. "A Comparative Analysis of Hand Dynamometers." Athletic Therapy Today 13, no. 2 (March 2008): 2–3. http://dx.doi.org/10.1123/att.13.2.2.

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Koehlen, Christoph, and Norbert Komoschinski. "Automated testing on exhaust emission dynamometers." ATZ worldwide 111, no. 10 (October 2009): 40–41. http://dx.doi.org/10.1007/bf03225098.

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O’Dogherty, M. J. "The Design of Octagonal Ring Dynamometers." Journal of Agricultural Engineering Research 63, no. 1 (January 1996): 9–18. http://dx.doi.org/10.1006/jaer.1996.0002.

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Paulus, Julien, Jerome Pauls, Laurent Radizzi, Laurent Krecke, Thierry Bury, Caroline Le Goff, Arnaud Laly, et al. "Knee strength measurement: Can we switch between isokinetic dynamometers?" Isokinetics and Exercise Science 29, no. 3 (July 20, 2021): 247–68. http://dx.doi.org/10.3233/ies-193193.

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BACKGROUND: Isokinetic evaluation is considered the gold standard in muscle strength measurement due to its sensitivity, intra-dynamometer reproducibility and usefulness in the injury prevention screening and follow up of subjects with musculoskeletal pathologies, neurological disease or after surgical operation. However, can one switch among different isokinetic dynamometers for the purpose of knee muscles evaluation? OBJECTIVES: To comprehensively evaluate the compatibility of the isokinetic short concentric and eccentric strength evaluation protocol and of the fatigability resistance evaluation between three different isokinetic devices. METHODS: Eighteen recreationally active men underwent three isokinetic knee testing sessions on three different isokinetic devices with 7–10 days of rest between each session. Relative (Pearson’s r product-moment correlation coefficient – PCC) and absolute (standard error of measurement – SEM, Cohen effect sizes (d) and probabilistic inferences – MBI) parameters of reproducibility were determined to assess the inter-dynamometer agreement. RESULTS: For the short concentric and eccentric strength evaluation protocol, the extensors in concentric mode and the flexors in eccentric mode can be compared (eventually with transposition formulas provided) between Biodex, Con-Trex and Cybex (almost all PCC ⩾ 0.80). The DCR could be compared between Con-Trex and Cybex and between Biodex and Cybex pairs (eventually with transposition formula provided). For the fatigability resistance evaluation protocol, the total sum can be compared for extensors (eventually with transposition formulas provided) for PM for all dynamometer pairs considered and, in the case of MW, only for Biodex and Con-Trex (PCC ⩾ 0.80). CONCLUSIONS: Only some of the parameters derived either from the short concentric and eccentric strength evaluation protocol or the fatigability resistance evaluation protocol may be interchangeable providing transposition formulas are applied. Otherwise, isokinetic findings are largely system-dependent save some specific instances.

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Kuenze, Christopher, Moataz Eltouhky, Abbey Thomas, Mark Sutherlin, and Joseph Hart. "Validity of Torque-Data Collection at Multiple Sites: A Framework for Collaboration on Clinical-Outcomes Research in Sports Medicine." Journal of Sport Rehabilitation 25, no. 2 (May 2016): 173–80. http://dx.doi.org/10.1123/jsr.2014-0314.

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Context:Collecting torque data using a multimode dynamometer is common in sports-medicine research. The error in torque measurements across multiple sites and dynamometers has not been established.Objective:To assess the validity of 2 calibration protocols across 3 dynamometers and the error associated with torque measurement for each system.Design:Observational study.Setting:3 university laboratories at separate institutions.Equipment:2 Biodex System 3 dynamometers and 1 Biodex System 4 dynamometer.Interventions:System calibration was completed using the manufacturer-recommended single-weight method and an experimental calibration method using a series of progressive weights. Both calibration methods were compared with a manually calculated theoretical torque across a range of applied weights.Main Outcome Measures:Relative error, absolute error, and percent error were calculated at each weight. Each outcome variable was compared between systems using 95% confidence intervals across low (0–65 Nm), moderate (66–110 Nm), and high (111–165 Nm) torque categorizations.Results:Calibration coefficients were established for each system using both calibration protocols. However, within each system the calibration coefficients generated using the single-weight (System 4 = 2.42 [0.90], System 3a = 1.37 [1.11], System 3b = –0.96 [1.45]) and experimental calibration protocols (System 4 = 3.95 [1.08], System 3a = –0.79 [1.23], System 3b = 2.31 [1.66]) were similar and displayed acceptable mean relative error compared with calculated theoretical torque values. Overall, percent error was greatest for all 3 systems in low-torque conditions (System 4 = 11.66% [6.39], System 3a = 6.82% [11.98], System 3b = 4.35% [9.49]). The System 4 significantly overestimated torque across all 3 weight increments, and the System 3b overestimated torque over the moderate-torque increment.Conclusions:Conversion of raw voltage to torque values using the single-calibration-weight method is valid and comparable to a more complex multiweight calibration process; however, it is clear that calibration must be done for each individual system to ensure accurate data collection.

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Shi, L. P., Bao Yuan Sun, and Min Qian. "The Effect of Secondary Piezoelectric Effect on the Measuring Precision of Quartz Dynamometers." Key Engineering Materials 291-292 (August 2005): 519–24. http://dx.doi.org/10.4028/www.scientific.net/kem.291-292.519.

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People apply quartz dynamometers to measure of milling force extensively. It is mainly made from piezoelectric quartz sensor. In this paper, the theory of the secondary piezoelectric effect is deduced by four kinds of piezoelectric equations. With the measuring the quartz stack secondary piezoelectric effect is verified. By theory and experiment we can show that the secondary piezoelectric effect makes elastic compliance constant of piezoelectric quartz smaller and do elastic stiffness constant of piezoelectric quartz bigger. Obviously, the secondary piezoelectric effect will have direct effect on the measuring precision of quartz dynamometers. So the investigations of secondary piezoelectric effect contribute to improving measuring precision of piezoelectric dynamometers.

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Yohanes, Yohanes, and Muhammad Rahdiyat Alqolbi. "Development of Dynamometer Based on Strain Gauge with Sensor Rod Type Four Square Stalk to Measuring the Drive Power of Rotary Friction Welding Machine." Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse) 64, no. 1 (March 30, 2020): 9–15. http://dx.doi.org/10.36842/jomase.v64i1.147.

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Friction welding is a type of solid state welding where the welding process is carried out in the solid phase. In the welding process there are several components that work, namely the electric motor as the main mover. This study aims to developmant a dynamometer to measure the mechanical power of a rotary friction welding machine. Dynamometer development includes the design, manufacture, calibration and testing of dynamometers. Dynamometer design that will be placed on the holder that serves as a stretch bar. Dimension of the strain dynamometer is 35 mm × 4 mm × 70 mm and serves to determine the motor torque value with the help of a 120 Ohm strain gauge sensor and to measure power it needs an additional speed sensor or optocoupler sensor to measure the motor angular speed. In need of making a microcontroller or an electrical device. Finally, the dynamometer testing process on a rotary friction welding machine. When the welding process takes place, the greater the pneumatic pressure exerted during welding, the more measurable the power is. The largest power value measured in the forging phase is 2408.50 Watts and the smallest power measured by the dynamometer is 2050.24 Watts at the initial rotation.

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Tounsi, Najeh, and Alain Otho. "Dynamometer Performance Modeling and Experimental Assessment." Journal of Dynamic Systems, Measurement, and Control 122, no. 3 (July 23, 1998): 477–82. http://dx.doi.org/10.1115/1.1286519.

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Piezoelectric dynamometers are generally used for force measuring. During transient period, their performance is limited because the signals they delivered are distorted by their dynamic behavior and then are different from applied force. This paper proposes a method to identify the dynamic characteristics of the dynamometer so that the distortion of the signal can be compensated leading to the actual force. This method is based on the interrupted cutting of a specially designed workpiece that provides a strong broadband excitation. The three components of the exciting force and the acceleration of the gravity center of the dynamometer cover plate are measured simultaneously. Although the input acceleration components are correlated in the frequency bandwidth of interest, the nine terms of the dynamometer transfer matrix are determined from only one cutting experiment. To assess the developed method, series of different pulse excitations are carried out. Then, the determined transfer matrix is used for dynamic cutting force compensation under some milling operations. [S0022-0434(00)01003-0]

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Guerra, R. S., and Teresa F. Amaral. "Comparison of hand dynamometers in elderly people." Journal of nutrition, health & aging 13, no. 10 (December 2009): 907–12. http://dx.doi.org/10.1007/s12603-009-0250-3.

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Fock, K. "Static and dynamic modeling of magnetoelastic dynamometers." Measurement 30, no. 1 (July 2001): 75–84. http://dx.doi.org/10.1016/s0263-2241(00)00058-0.

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Jin, Wenlin, and P. K. Venuvinod. "Interaction elimination for multicomponent strain-gauge dynamometers." Sensors and Actuators A: Physical 50, no. 1-2 (August 1995): 1–6. http://dx.doi.org/10.1016/0924-4247(95)01033-w.

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Yohanes, Yohanes, and Novri Andri. "Performance of Dynamometer with Sensor Type Single Bar for Measuring Drive Power of Rotary Friction Welding Machine." Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse) 64, no. 3 (November 30, 2020): 73–80. http://dx.doi.org/10.36842/jomase.v64i3.146.

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This study aims to determine the performance of the dynamometer design as a measure of mechanical power on a rotary friction welding machine. The design of the dynamometer includes the design, manufacture, calibration, and testing of the dynamometer. The design and manufacture of strain dynamometers is adjusted to the motor of the rotary friction welding machine at the University of Riau's Mechanical Engineering Production Technology Laboratory. The design of the strain dynamometer has a dimension of 175 mm × 3 mm × 50 mm and serves to determine the motor torque value with the help of a 120 ohm strain gauge sensor. The device designed is equipped with an electrical microcontroller device and an optocoupler sensor to measure the angular speed of the motor. Next, the dynamometer performance testing is performed on the rotary friction welding machine. The results of testing in the rotary welding process, the greater the pneumatic pressure exerted during welding, the greater the measured power. The largest measured power value is 2452.92 Watt in the forging process, and the smallest measured power value is 2050.24 Watt in the first time of the initial motor rotation. After doing the research, it can be concluded that the tools designed and built can work and have a fairly good performance.

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Sir Anderson. "Dinamometer Untuk Alat Uji penarikan Kawat (Perancangan, Pembuatan dan Pengujian)." Jurnal Ilmiah Poli Rekayasa 14, no. 1 (October 15, 2018): 72. http://dx.doi.org/10.30630/jipr.14.1.113.

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The basic principle of metal formation is to change shape by giving an external force so that plastic deformation occurs. One example of this formation is wire drawing. The important parameter in wire drawing is the drawing force, which is the force needed to deform the wire to produce the desired reduction. The measurement of withdrawal force is carried out through a wire drawing test equipped with a dynamometer, which consists of load cell and strain gauge. From this test, the withdrawal force can be measured as an electrical quantity that can be read using a multitester or computer. For wire drawing testing dynamometers are designed and made as measuring sensors for withdrawal forces on a laboratory scale. From the results of testing with a dynamometer the average wire drawing force for copper reduction I was 72.88 kgf, copper reduction II was 95.88 kgf and brass was 126.50 kgf. The price of this test is greater than the theoretical price

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Mendonca, Rochelle, Ashley Bauer, Rachel Lyons, and Colleen Maher. "Establishing Norms for the Bulb Dynamometer and Evaluating Pain and Comfort Differences Between the Bulb and Jamar Dynamometers." American Journal of Occupational Therapy 72, no. 4_Supplement_1 (November 1, 2018): 7211500061p1. http://dx.doi.org/10.5014/ajot.2018.72s1-po7005.

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Mendonca, Rochelle, Colleen Maher, Jennifer Wright, Maribeth Keith, Aaron Simon, Angeline Danan, Rachelle Aningalan, and Vien Phan. "Evaluating Pain and Comfort Differences Between the Bulb and Jamar Dynamometers and Establishing Norms for the Bulb Dynamometer." American Journal of Occupational Therapy 73, no. 4_Supplement_1 (August 1, 2019): 7311500060p1. http://dx.doi.org/10.5014/ajot.2019.73s1-po8027.

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KAYMAK, B., F. İNANICI, L. ÖZÇAKAR, A. ÇETIN, A. AKINCI, and Z. HASÇELIK. "Hand Strengths in Carpal Tunnel Syndrome." Journal of Hand Surgery (European Volume) 33, no. 3 (June 2008): 327–31. http://dx.doi.org/10.1177/1753193408090105.

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The purpose of this study was to determine whether a measurable decrease in isokinetic (dynamic) and isometric (static) hand strengths occurs in carpal tunnel syndrome (CTS) patients. Eighteen CTS patients and 20 healthy controls were included in the study. Isokinetic (eccentric and concentric) and isometric grip and pinch strengths were measured with a Biodex System 3 dynamometer (Biodex Medical System, Inc. New York). All strength measurements, except isometric and isokinetic (concentric/eccentric) three-point pinch and isokinetic (concentric) tip pinch, revealed statistically significant differences between CTS patients and controls. Measurable decrease in hand strengths may exist in CTS despite normal manual assessments. Although both isokinetic (dynamic) and isometric (static) dynamometers are capable of detecting this decrease, neither technique seems better than the other.

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Bohannon, R. W. "Hand-held compared with isokinetic dynamometry for measurement of static knee extension torque (parallel reliability of dynamometers)." Clinical Physics and Physiological Measurement 11, no. 3 (August 1990): 217–22. http://dx.doi.org/10.1088/0143-0815/11/3/004.

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Jun, Zhang, Chang Qingbing, and Ren Zongjin. "Research on a non-linear calibration method for dynamometer." Sensor Review 40, no. 2 (March 9, 2020): 167–73. http://dx.doi.org/10.1108/sr-07-2019-0181.

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Purpose The purpose of this paper is to solve the problem that the relationship between loading forces, which were applied at different positions on a plane, and output values of load-sharing dynamometer is non-linear. Design/methodology/approach First, the analytical model of ISPM (isodynamic surface proportional mapping method) method, which is used to calibrate dynamometer, was established. Then, a series of axial force calibration tests were performed on a load-sharing dynamometer at different loading positions. Finally, according to output values, calibration forces at different loading positions were calculated by ISPM method, and corresponding distribution histogram of calibration force error was generated. Findings The largest error between calculated force and standard force is 2.92 per cent, and the probability of calculated force error within 1 per cent is 91.03 per cent, which verify that the ISPM method is reliable for non-linear calibration of dynamometers. Originality/value The proposed ISPM method can achieve non-linear calibration between measured force and output signal of load-sharing dynamometer at different positions. In addition, ISPM method can also solve some complex non-linear problems, such as prediction of plane cutting force under the influence of multiple parameters, the force measurement of multi-degree-of-freedom platform and so on.

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Passenbrunner, Thomas E., Mario Sassano, Markus Hirsch, and Luigi del Re. "Identification and Inverse Torque Control of Hydrodynamic Dynamometers." IEEE Transactions on Control Systems Technology 22, no. 2 (March 2014): 607–17. http://dx.doi.org/10.1109/tcst.2013.2262531.

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Mindova, S., I. Karaganova, and I. Stefanova. "Procedural Options for Measuring Muscle Strength." Acta Medica Bulgarica 43, no. 2 (October 1, 2016): 80–85. http://dx.doi.org/10.1515/amb-2016-0020.

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Summary The aim of the present study was to provide alternative means of measurement and evaluation of muscle strength in rehabilitation practice and diagnostics. In the last few years many electronic devices for evaluation of muscle strength have developed. Contemporary studies have shown that in addition to the standard manual muscle testing muscle strength can be assessed more objectively and analytically using electronic dynamometers and equipment. The strain gauges are used as a tool of precision in the industry that allows measurement of mechanical loads by dynamometers. By using these tools is possible to obtain continuous digital measurement and recording of muscle strength.

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Пономарев, Борис, Boris Ponomarev, Ши Нгуен, and Shi Nguen. "DYNAMOMETER CHOICE FOR CUTTING FORCE MEASUREMENT AT END MILLING." Bulletin of Bryansk state technical university 2019, no. 5 (June 4, 2019): 15–24. http://dx.doi.org/10.30987/article_5cda64cc611ed4.66880449.

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In the paper there are presented results of the comparison of dynamometers of three types with reference to measurements connected with the definition of values making cutting forces in the course of blank finish five-coordinate milling with spherical-cylindrical mill cutters with the diameter from 5 to 10 mm. At that a particular attention is paid to the protection of these devices against external influences, to the processing possibility of data obtained in measuring equipment with the use of program applications. The measurement series of cutting forces with the aid of a stationary dynamometer and a rotary one allowed revealing basic advantages and drawbacks of both of them. The assessment results of forces measured at tool idling and in the course of machining allowed drawing a conclusion of that the use of the stationary dynamometer of Kistler Type 9129AA is most preferable. The measurement series carried out allowed confirming the results of theoretical investigations and machining dynamics modeling, and also defining the impact of a tool position regarding a normal upon measurement processes and data reliability.

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Mohanraj, T., S. Shankar, R. Rajasekar, and M. S. Uddin. "Design, development, calibration, and testing of indigenously developed strain gauge based dynamometer for cutting force measurement in the milling process." Journal of Mechanical Engineering and Sciences 14, no. 2 (June 30, 2020): 6594–609. http://dx.doi.org/10.15282/jmes.14.2.2020.05.0517.

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In this work, a milling dynamometer based on strain gauge with an octagonal and square ring was designed and tested. Strain gauges were attached with the mechanical rings to detect the deformation, during the machining process. Wheatstone bridge circuit was equipped with gauges to acquire the strain as voltage owing to the deformation of mechanical rings when machining takes place. The finite element analysis (FEA) was used to identify the location of maximum deformation and stress. The direction of rings and location of gauges were decided to increase the sensitivity and decrease the cross-sensitivity. Then, the cutting force was acquired through NI 6221 M series data acquisition (DAQ) card. The dynamometer had undergone a cycle of tests to verify its static and dynamic characteristics. The metrological characterization was performed according to the calibration procedure based on ISO 376 – 2011 standard. The cutting force was measured with both the dynamometers through milling experiments based on Taguchi’s L9 orthogonal array and the results were recorded. The measured cutting force varied from 300 N to 550 N. The obtained results depicted that low-cost milling dynamometer was reliable to measure the three component machining force. Overall, the square ring based dynamometer provides the better static and dynamic characteristics in terms of linearity, cross-sensitivity (4%), uncertainty (0.054%), and natural frequency (362.41 rev/s).

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Díaz Muñoz, Gustavo Alfonso, and Sandra Julieth Calvera Millán. "Comparing the Camry dynamometer to the Jamar dynamometer for use in healthy Colombian adults." Revista Salud Bosque 9, no. 2 (December 8, 2019): 21–29. http://dx.doi.org/10.18270/rsb.v9i2.2794.

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Objective: Hand grip strength can provide an objective index of general upper strength, but hand dynamometer has not been validated for use in Colombia. The objective was to determine the interchangeability between Camry electronic and Jamar hydraulic hand grip dynamometers in a population found on the campus of the Universidad Nacional de Colombia and the elderly living in a community. Methods: This was a cross-sectional concordance study on 18-88-year-old males and females. Data regarding their demographics, health, and anthropometric variables were collected/measured and the Lin concordance correlation coefficient (CCC) along with Bland-Altman plots were used for evaluating concordance regarding both devices. Results: One hundred and thirty-three subjects participated in this study (average age 47±20.74 years-old). Right hand (RH) grip strength was 32.15 ± 9.96 kg with the Jamar dynamometer and 29.95 ± 9.18 kg with the Camry device. It is worth highlighting that the Jamar instrument presents higher values than the Camry instrument (p <0.05). CCC was only significant at the population level and for the 40-59-year-old age group. Bland-Altman plots had narrow limits of agreement. Conclusion: We concluded that the Camry dynamometer could replace the Jamar dynamometer in the 40-59-year-old age group; furthermore, it would be appropriate for medical use in patient monitoring or follow-up due to the close values observed.

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Sorensen, H., M. Zacho, E. B. Simonsen, P. Dyhre-Poulsen, and K. Klausen. "Joint angle errors in the use of isokinetic dynamometers." Isokinetics and Exercise Science 7, no. 3 (July 1, 1998): 129–33. http://dx.doi.org/10.3233/ies-1998-0028.

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Lindstrom-Hazel, D., A. Kratt, and L. Bix. "Interrater Reliability of Students Using Hand and Pinch Dynamometers." American Journal of Occupational Therapy 63, no. 2 (March 1, 2009): 193–97. http://dx.doi.org/10.5014/ajot.63.2.193.

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Millican, J., and G. Murrell. "Can handheld dynamometers diagnose partial-thickness rotator cuff tears?" Journal of Science and Medicine in Sport 14 (December 2011): e32. http://dx.doi.org/10.1016/j.jsams.2011.11.067.

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Millican, Jared P., and George A. C. Murrell. "Can Handheld Dynamometers Diagnose Partial-thickness Rotator Cuff Tears?" Shoulder & Elbow 4, no. 2 (April 2012): 100–105. http://dx.doi.org/10.1111/j.1758-5740.2011.00173.x.

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Castañer, Ramón, José M. Medina, and María J. Cuesta-Bolao. "The magnetic dipole interaction as measured by spring dynamometers." American Journal of Physics 74, no. 6 (June 2006): 510–13. http://dx.doi.org/10.1119/1.2180286.

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Düser, Tobias, Christoph Schmidt, Uwe Schmidt, and Felix Pfister. "Chassis dynamometers for vehicle and powertrain concepts of tomorrow." ATZ worldwide 114, no. 4 (April 2012): 12–16. http://dx.doi.org/10.1007/s38311-012-0163-3.

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Journal articles on the topic 'Dynamometers'

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