Physical Therapy in Sport
Volume 6, Issue 1 , Pages 38-44, February 2005

Knee extensor stiffness and functional performance

  • Greg Owen

      Affiliations

    • New Zealand Institute of Sport and Recreation Research, Auckland University of Technology, Private Bag 92006, Auckland 1020, New Zealand
    • Corresponding Author InformationCorresponding author. Tel.: +64 9 917 9999x7353; fax: +64 9 917 9746.
    • ,
  • John Cronin

      Affiliations

    • New Zealand Institute of Sport and Recreation Research, Auckland University of Technology, Private Bag 92006, Auckland 1020, New Zealand
    • ,
  • Nicholas Gill

      Affiliations

    • Waikato Institute of Technology, Private Bag 3036, Hamilton 2020, New Zealand
    • ,
  • Peter McNair

      Affiliations

    • Auckland University of Technology, Private Bag 92006, Auckland 1020, New Zealand

Received 2 February 2004; received in revised form 16 November 2004; accepted 17 November 2004.

Abstract 

Objective

To determine the reliability of a new method to measure the stiffness of the knee extensors and thereafter establish the relationship between knee extensor stiffness and, jump and running performance.

Setting

A professional rugby union football club and a university laboratory.

Participants

Thirty semi-elite male rugby union players.

Main outcome measures

The stiffness of the knee extensors across loads ranging from 30 to 70% maximal voluntary isometric contraction, 20m sprint, maximal squat strength, countermovement-jump and drop-jump performance was assessed.

Results

Within trial variation (coefficient of variation—range 5.41–7.45%) for all five loads (30, 40, 50, 60 and 70%) and test–retest reliability (intra-class correlation coefficients—range 0.92–0.96) were deemed acceptable. Knee extensor stiffness was found to have no significant relationship (P>0.05) to any of the functional performance measures (r=−0.160–0.172).

Conclusion

It was concluded that the new protocol to assess the stiffness of the knee extensors was reliable, however the relationship between knee extensor stiffness and measures of strength, power and speed was weak and non-significant.

Keywords: Speed, Strength, Power, Knee stiffness

To access this article, please choose from the options below

Login to an existing account or Register a new account.

  • Purchase this article for 31.50 USD (You must login/register to purchase this article)

    Online access for 24 hours. The PDF version can be downloaded as your permanent record.

  • Subscribe to this title

    Get unlimited online access to this article and all other articles in this title 24/7 for one year.

  • Claim access now

    For current subscribers with Society Membership or Account Number.

  • Visit SciVerse ScienceDirect to see if you have access via your institution.
 

PII: S1466-853X(04)00123-3

doi:10.1016/j.ptsp.2004.11.003

Physical Therapy in Sport
Volume 6, Issue 1 , Pages 38-44, February 2005

Article Tools

* Image Usage & Resolution