J Korean Acad Kinesiol Search

CLOSE


Asian J Kinesiol > Volume 19(4); 2017 > Article
The Official Journal of the Korean Academy of Kinesiology 2017;19(4):29-35.
DOI: https://doi.org/10.15758/jkak.2017.19.4.29    Published online October 30, 2017.
Reliability of Isokinetic Knee Strength Measurements Using Genneralizability Theory.
Han-Joon Lee, Minsoo Kang
University of Ulsan
University of Mississippi
Correspondence:  Han-Joon Lee,
Email: hanjoon@ulsan.ac.kr
Received: 21 August 2017   • Accepted: 19 October 2017
Abstract
PURPOSE
Isokinetic strength test is the measurement of force-velocity or torque angle. Isokinetic strength of the knee extensor and flexor muscle is often assessed using an isokinetic dynamometor such as Cybex system. Question remains concerning the reliability of the isokinetic muscle strength measurements. The purpose of this study was to establish the minimum number of trial required to assess reliable estimates of isokinetic strength measurement using Cybex system(Cybex 770).
METHODS
A total of 70 adults (mean age 19.38 ± 3.32 years; 35 male and female each) completed the isokinetic strength tests using Cybex system. Concentric muscle strengths were measured at 60 degrees per second over 4 repetitions. Following data screening, participant’s data were finally analyzed by muscle strength measurements (knee extensor and flexor muscles) and gender using the Genealizability theory. A single-facet crossed design [i.e., participant(P) × trial(T)] was used. G-study was performed to quantify the percentage of variance associated with each facet and interaction in the model. Follow-up D-study was performed to determine the optimal combinations of number of repetition trial to achieve a desirable reliability coefficient (G≥.80).
RESULTS
The knee extensor muscle of male and female were 158.48 ± 33.89Nm and 96.78 ± 23.60Nm respectively. The knee flexor muscle of male and female were 83.52 ± 31.92Nm and 45.97 ± 11.94Nm, respectively. For the knee extensor muscle, the results from G-study show that P accounted for 71% and 90% variance for male and female. T had no effect on the total variance. The number of trials to achieve G≥.80 for male and female were 2 and 1, respectively. For the knee muscle G-study results show that P accounted for 94% and 77% variance for male and female. T had little effect on the total variance (< 1%). The number of trials to achieve G≥.80 for male and female were 1 and 2, respectively.
CONCLUSIONS
The number of examination for reliable values is at least 2 times in isokinetic knee strength test.
Keywords: reliability, isokinetic, knee strength, generalizability theory
TOOLS
Share :
Facebook Twitter Linked In Google+ Line it
METRICS Graph View
  • 0 Crossref
  •    
  • 349 View
  • 9 Download
Related articles in AJK


ABOUT
BROWSE ARTICLES
ARTICLE CATEGORY

Browse all articles >

AUTHOR INFORMATION
Editorial Office
10-302 Gangnam Sangga, 303, Hyoryong-ro, Seochogu, Seoul, 06643 Korea
Tel: +82-10-4044-3814    E-mail: ajk.editor@gmail.com                

Copyright © 2018 by The Asian Society of Kinesiology and the Korean Academy of Kinesiology. All rights reserved.

Developed in M2community

Close layer
prev next