Assessment of Technical Accuracy of the Cybex II<sup>®</sup>Isokinetic Dynamometer and Analog Recording System

Bemben, M. G.; Grump, K. J.; Massey, Benjamin H.

doi:10.2519/jospt.1988.10.1.12

Cited by 27 publications

(8 citation statements)

References 2 publications

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“…By the same token, attention must be paid to the angle at which torque is recorded in an analysis of validity. For example, it is entirely possible for an isokinetic device to measure accurately the torque at a single angle (2) o r averaged within a chosen arc of motion (5) and still have no validity throughout the remainder of the range.…”

Section: Discussionmentioning

confidence: 99%

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Validity and Reliability of the LIDO Active Isokinetic System

Patterson¹,

Spivey²

1992

J Orthop Sports Phys Ther

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, PT2ew studies have examined validity and reliability of an isokinetic device using instrumentation that had "proven" technical accuracy instead of human subjects, who are inherently unreliable. One example is the study by Farrell and Richards (5). who looked at validity and reliability of the Kincom (Chattecx Corporation, Chattanooga, TN). While they were able to show significant validity and reliability for both angular velocity and torque, their measurements of force were averaged over the middle 25" of the lever arm stroke rather than being compared at specific angles throughout the arc of motion.Bemben et al (2) evaluated the technical accuracy of the Cybex I1 (Lumex, Inc., Ronkonkoma, NY) for velocity, torque, and the effects of damping on velocity and torque. Their results indicated that the Cybex I1 was accurate for both velocity and peak torque, provided that damping was set at four during calibration and testing. As with the Farrell and Richards study, Bemben et al failed to assess validity and reliability over a broad range of motion. They looked instead at peak torque, which had a variable angle of occurrence.Aitkens et al (1) examined the validity of the LIDO Digital isokinetic system (Loredan, Inc., Davis, CA) by dropping weights ranging from 1.36 to 99.5 Ib using a 2-ft leWhen evaluating a strength testing method, reliability rather than validity, the most critical component, is most frequently addressed. The purpose of this study was to assess the validity and reliability of the 11170 Active system in the isokinetic mode. Velocity and torque were continuously monitored while torques of 10.4, 25.6, 30.6, and 89.6 ft-lb ver arm through a 180" arc. Their study was done at velocities of 5 and 60°/sec. They recorded only peak torque and neglected to measure the angle of occurrence. Although the Lido Digital was accurate for peak torque, the authors failed to determine validity over a broad range of motion.Davies (4) concluded that the power to body weight ratio is the single most important value that can be obtained from isokinetic testing. In order for power to be measured accurately, however, the isokinetic device must be validated at many angles throughout the arc of motion. The purpose of the present study is to determine the validity and reliability of the LIDO Active isokinetic device (Loredan, Inc., Davis, CA), using preselected angles over a broad range of motion. MATERIALS AND METHODSThe first step in the study was to test the quality of data that could be obtained from the measurement devices. The validity and reliability of an RCA VHS camcorder (model #CC250, Indianapolis, Indiana) and a Sears DA4 Head H Q VHS videocassette recorder (Sears, Roebuck and Co., Chicago, IL) were determined using the following protocol. A Casio Databank wristwatch (model #DBC-6 1, Japan) was filmed to record time accurate to 0.0 1 sec and played back on the VCR using single-framed advance to determine the number of frames per second. This

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Section: Discussionmentioning

confidence: 99%

“…Bemben et al (2) evaluated the technical accuracy of the Cybex I1 (Lumex, Inc., Ronkonkoma, NY) for velocity, torque, and the effects of damping on velocity and torque. Their results indicated that the Cybex I1 was accurate for both velocity and peak torque, provided that damping was set at four during calibration and testing.…”

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confidence: 99%

Validity and Reliability of the LIDO Active Isokinetic System

Patterson¹,

Spivey²

1992

J Orthop Sports Phys Ther

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“…PT has been shown to be an accurate and highly reproducible variable to measure (6,8,24,43,48,53,54,62,63,67,72), and its use in isokinetic tests has been accepted in critical reviews (4, 66,67). PT has become a gold standard and reference point in all isokinetic measurements against which accuracy, precision, and clinical relevance of all other parameters should be compared.…”

Section: Peak Torquementioning

confidence: 99%

Isokinetic Evaluation of Muscular Performance

Kannus¹

1994

Int J Sports Med

361

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Interfacing of microprocessors with isokinetic dynamometers has enabled the rapid quantification of many parameters of muscle function including peak torque, angle-specific torque, work, power, torque acceleration energy, and various endurance indexes, and the measurements with these devices can be made isometrically at various angular positions and isokinetically (concentrically or eccentrically) with a large scale of angular speeds. Many of these parameters, however, lack evidence of validity, reproducibility, and/or clinical relevance. Peak torque has been and still is the most properly studied isokinetic strength testing parameter and its use can be recommended for research and clinical purposes. Concerning testing of muscular endurance, the absolute endurance parameters (for example, work performed during the last five repetitions and total work in a 25-repetition test with a speed of 240 degrees/s) are the best for use. Many internal and external factors in the isokinetic testing procedure can have an undesirable effect on the test result. However, through proper education and strict adherence to the test instructions, it is possible to successfully control the confounding variables. In scientific work, isokinetic devices have greatly expanded the possibilities for studying dynamic muscle function. There is also little doubt about their usefulness in documenting the progress of muscular rehabilitation. A disadvantage of isokinetic devices is that isokinetic movement seldom occurs in actual human performance tasks and that the isokinetic training effect is, therefore, quite (although not completely) specific to that type of movement. In addition, being normally an isolated joint exercise, isokinetic training can produce large loads on the involved joints and may, therefore, under certain conditions be dangerous for healing tissues.

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“…Measures of torque and angular velocity using a variety of isokinetic dynamometers have been found to be both mechanically reliable (Farrell and Richards 1986;Timm et al 1992) and valid (Bemben et al 1988;Farrell and Richards 1986;Patterson et al 1992). The Biodex System 3 isokinetic dynamometer (Biodex Medical Systems, Shirley, New York, USA) is a contemporary isokinetic dynamometer with an electrically controlled servomechanism used in both clinical and research settings.…”

Section: Introductionmentioning

confidence: 97%

Reliability and validity of the Biodex system 3 pro isokinetic dynamometer velocity, torque and position measurements

Drouin

McLeod

Shultz

et al. 2004

European Journal of Applied Physiology

592

116

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This study quantitatively assessed the mechanical reliability and validity of position, torque and velocity measurements of the Biodex System 3 isokinetic dynamometer. Trial-to-trial and day-to-day reliability were assessed during three trials on two separate days. To assess instrument validity, measurement of each variable using the Biodex System 3 dynamometer was compared to a criterion measure of position, torque and velocity. Position was assessed at 5 degrees increments across the available range of motion of the dynamometer. Torque measures were assessed isometrically by hanging six different calibrated weights from the lever arm. Velocity was assessed (30 degrees/s to 500 degrees/s) across a 70 degrees arc of motion by manually accelerating the weighted lever arm. With the exception of a systematic decrease in velocity at speeds of 300 degrees/s and higher, the Biodex System 3 performed with acceptable mechanical reliability and validity on all variables tested.

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Assessment of Technical Accuracy of the Cybex II^®Isokinetic Dynamometer and Analog Recording System

Cited by 27 publications

References 2 publications

Validity and Reliability of the LIDO Active Isokinetic System

Validity and Reliability of the LIDO Active Isokinetic System

Isokinetic Evaluation of Muscular Performance

Reliability and validity of the Biodex system 3 pro isokinetic dynamometer velocity, torque and position measurements

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Assessment of Technical Accuracy of the Cybex II®Isokinetic Dynamometer and Analog Recording System

Cited by 27 publications

References 2 publications

Validity and Reliability of the LIDO Active Isokinetic System

Validity and Reliability of the LIDO Active Isokinetic System

Isokinetic Evaluation of Muscular Performance

Reliability and validity of the Biodex system 3 pro isokinetic dynamometer velocity, torque and position measurements

Contact Info

Product

Resources

About

Assessment of Technical Accuracy of the Cybex II^®Isokinetic Dynamometer and Analog Recording System