Learning effect of isokinetic measurements in healthy subjects, and reliability and comparability of Biodex and Lido dynamometers

Abstract

The aim of this study was to examine the learning effect during a set of isokinetic measurements, to evaluate the reliability of the Biodex System 3 PRO dynamometer, and to compare the Biodex System 3 PRO and the Lido Active dynamometers on both extension and flexion over the elbow and the knee at 60 degrees s(-1). Thirteen (nine women, four men) healthy participants were measured five times using the Biodex and once using the Lido dynamometer. The intervals between the first four tests were 20 min, and 1 week between tests 4 and 5. Between Biodex and Lido measurements there was a 20 min time interval. When comparing the first five measurements (Biodex), no systematic effect over time and an excellent reliability were found with respect to elbow and knee flexion and extension. No difference in muscle strength (Nm) between the Biodex and Lido was observed for knee flexion (P = 0.59), knee extension (P = 0.18) and elbow extension (P = 0.63). However, elbow flexion showed a 14.8% (95% CI: 11.2-18.4%; P = 0.0001) higher peak torque on Biodex. In conclusion, no learning effect was observed and the Biodex proved to be a highly reliable isokinetic dynamometer. A difference was observed when comparing Biodex and Lido on elbow flexion, but the difference did not outrange the expected variation found with a typical isokinetic measurement, which is why both sets of equipment seem applicable in clinical practice.

Age-related decline in muscle mass and muscle function in Flemish Caucasians: a 10-year follow-up

“…Furthermore, it cannot distinguish true change from measurement error (Singer and Willett 2003). Test-retest reliability for Biodex measurements has been previously reported to be high (Lund et al 2005). Also, no learning effects were observed for the Biodex measurements.…”

“…Also, no learning effects were observed for the Biodex measurements. Measurement error was 11.75 Nm for the isokinetic strength at 60°/s based on the reported findings in Lund et al (2005). Interpretation of the change in PT dynamic60°s hould therefore be made taking these results into account, as should the changes in other strength performance parameters.…”

Test-Retest Reliability of Isometric Leg Muscle Strength Measurements Made Using a Hand-Held Dynamometer Restrained by a Belt: Comparisons during and between Sessions

“…They repeated the measurements 72 hours to 1 week later and found that ICC ranged from 0.59 to 0.74. Lund et al 10) used an isokinetic dynamometer (BIODEX) to measure the strength of extension and flexion of the knee and elbow of 13 healthy men and women with an average age of 32 years. They repeated the measurements after intervals of 20 h and 1 week and reported that ICC ranged from 0.96 to 0.98 for the 3 rd and 4 th measurements taken 20 minutes apart and ranged from 0.89 to 0.97 for measurements taken 1 week apart.…”

“…In a study by Agre et al 8) using 4 healthy subjects and 3 raters, Pearson correlation coefficients for interrater measurements ranged from -0.19 to 0.96 for the lower extremity, and from 0.88 to 0.94 for the upper extremity. Regarding the limitations of measurements using a hand-held dynamometer(HHD), Hyde et al 10) claimed that, regardless of the tester's experience or power of resistance, 30 kg is the limit, while Wiles et al 11) and Roebeck et al 12) , claimed respectively that it is difficult to maintain the position of the HHD at forces of 300 N and 85 Nm or higher.…”

Functioning and Disability in Patients With Hip Osteoarthritis With Mild to Moderate Pain

“…31 The primary outcome measure was isokinetic knee extension peak torque values, with estimation of 150 (36) Nm for subjects without hip OA and 105 (37) Nm for patients with hip OA. 32 Based on 5% significance level and 90% power, 17 subjects were needed to be included in each group. If a subject in 1 of the 2 groups dropped out from a test, the matched pair was excluded.…”