Skip to main content
PMC home page
British Journal of Sports Medicine logoLink to British Journal of Sports Medicine
. 1996 Jun;30(2):156–160. doi: 10.1136/bjsm.30.2.156

Eccentric and concentric isokinetic knee flexion and extension: a reliability study using the Cybex 6000 dynamometer.

R C Li 1, Y Wu 1, N Maffulli 1, K M Chan 1, J L Chan 1
PMCID: PMC1332382  PMID: 8799603

Abstract

OBJECTIVE: To determine the reliability of the Cybex 6000 isokinetic dynamometer in measuring the knee muscle performance concentrically and eccentrically. METHODS: 18 male and 12 female subjects with no previous knee injuries, who had not previously undergone any isokinetic testing, were studied. The flexor and extensor muscles groups of both knees were tested at 60 degrees s-1 and 120 degrees s-1 with the continuous concentric-eccentric cycle testing protocol. Variables studied included peak torque, total work, and average power. The interclass correlation coefficient (ICC 2,1) was used to determine the reliability with P < 0.05. RESULTS: Peak torque showed significantly greater ICC than the total work and average power, with test-retest reliability ranging from 0.82 to 0.91 for peak torque, from 0.76 to 0.89 for total work, and 0.71 to 0.88 for average power. Average variability for the three variables studied ranged from 9% to 14%. The ICCs for the three variables studied were significantly greater at 120 degrees s-1. The knee extensor muscle group showed greater test-retest reliability, and the results of isokinetic testing in the concentric contraction mode were more reproducible. CONCLUSIONS: The Cybex 6000 isokinetic dynamometer shows high reliability in measuring isokinetic concentric and eccentric variables. Some fluctuation should be allowed when evaluating variations of muscle performance between tests.

Full text

PDF
160

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bandy W. D., McLaughlin S. Intramachine and intermachine reliability for selected dynamic muscle performance tests. J Orthop Sports Phys Ther. 1993 Nov;18(5):609–613. doi: 10.2519/jospt.1993.18.5.609. [DOI] [PubMed] [Google Scholar]
  2. Bennett J. G., Stauber W. T. Evaluation and treatment of anterior knee pain using eccentric exercise. Med Sci Sports Exerc. 1986 Oct;18(5):526–530. [PubMed] [Google Scholar]
  3. Brown L. P., Niehues S. L., Harrah A., Yavorsky P., Hirshman H. P. Upper extremity range of motion and isokinetic strength of the internal and external shoulder rotators in major league baseball players. Am J Sports Med. 1988 Nov-Dec;16(6):577–585. doi: 10.1177/036354658801600604. [DOI] [PubMed] [Google Scholar]
  4. Farrell M., Richards J. G. Analysis of the reliability and validity of the kinetic communicator exercise device. Med Sci Sports Exerc. 1986 Feb;18(1):44–49. [PubMed] [Google Scholar]
  5. Frontera W. R., Hughes V. A., Dallal G. E., Evans W. J. Reliability of isokinetic muscle strength testing in 45- to 78-year-old men and women. Arch Phys Med Rehabil. 1993 Nov;74(11):1181–1185. [PubMed] [Google Scholar]
  6. Griffin J. W. Differences in elbow flexion torque measured concentrically, eccentrically, and isometrically. Phys Ther. 1987 Aug;67(8):1205–1208. doi: 10.1093/ptj/67.8.1205. [DOI] [PubMed] [Google Scholar]
  7. Harries U. J., Bassey E. J. Torque-velocity relationships for the knee extensors in women in their 3rd and 7th decades. Eur J Appl Physiol Occup Physiol. 1990;60(3):187–190. doi: 10.1007/BF00839157. [DOI] [PubMed] [Google Scholar]
  8. Hislop H. J., Perrine J. J. The isokinetic concept of exercise. Phys Ther. 1967 Feb;47(2):114–117. [PubMed] [Google Scholar]
  9. Hortobagyi T., Katch F. I. Reliability of muscle mechanical characteristics for isokinetic and isotonic squat and bench press exercise using a multifunction computerized dynamometer. Res Q Exerc Sport. 1990 Jun;61(2):191–195. doi: 10.1080/02701367.1990.10608674. [DOI] [PubMed] [Google Scholar]
  10. Johnson J., Siegel D. Reliability of an isokinetic movement of the knee extensors. Res Q. 1978 Mar;49(1):88–90. [PubMed] [Google Scholar]
  11. Kramer J. F. Reliability of knee extensor and flexor torques during continuous concentric-eccentric cycles. Arch Phys Med Rehabil. 1990 Jun;71(7):460–464. [PubMed] [Google Scholar]
  12. Mawdsley R. H., Knapik J. J. Comparison of isokinetic measurements with test repetitions. Phys Ther. 1982 Feb;62(2):169–172. doi: 10.1093/ptj/62.2.169. [DOI] [PubMed] [Google Scholar]
  13. Moffroid M., Whipple R., Hofkosh J., Lowman E., Thistle H. A study of isokinetic exercise. Phys Ther. 1969 Jul;49(7):735–747. doi: 10.1093/ptj/49.7.735. [DOI] [PubMed] [Google Scholar]
  14. Pedegana L. R., Elsner R. C., Roberts D., Lang J., Farewell V. The relationship of upper extremity strength to throwing speed. Am J Sports Med. 1982 Nov-Dec;10(6):352–354. doi: 10.1177/036354658201000606. [DOI] [PubMed] [Google Scholar]
  15. Rizzardo M., Wessel J., Bay G. Eccentric and concentric torque and power of the knee extensors of females. Can J Sport Sci. 1988 Jun;13(2):166–169. [PubMed] [Google Scholar]
  16. Steiner L. A., Harris B. A., Krebs D. E. Reliability of eccentric isokinetic knee flexion and extension measurements. Arch Phys Med Rehabil. 1993 Dec;74(12):1327–1335. doi: 10.1016/0003-9993(93)90088-r. [DOI] [PubMed] [Google Scholar]
  17. Thistle H. G., Hislop H. J., Moffroid M., Lowman E. W. Isokinetic contraction: a new concept of resistive exercise. Arch Phys Med Rehabil. 1967 Jun;48(6):279–282. [PubMed] [Google Scholar]
  18. Thorstensson A., Grimby G., Karlsson J. Force-velocity relations and fiber composition in human knee extensor muscles. J Appl Physiol. 1976 Jan;40(1):12–16. doi: 10.1152/jappl.1976.40.1.12. [DOI] [PubMed] [Google Scholar]
  19. Tredinnick T. J., Duncan P. W. Reliability of measurements of concentric and eccentric isokinetic loading. Phys Ther. 1988 May;68(5):656–659. doi: 10.1093/ptj/68.5.656. [DOI] [PubMed] [Google Scholar]
  20. Wilk K. E., Andrews J. R., Arrigo C. A., Keirns M. A., Erber D. J. The strength characteristics of internal and external rotator muscles in professional baseball pitchers. Am J Sports Med. 1993 Jan-Feb;21(1):61–66. doi: 10.1177/036354659302100111. [DOI] [PubMed] [Google Scholar]

Articles from British Journal of Sports Medicine are provided here courtesy of BMJ Publishing Group

RESOURCES