You are viewing a javascript disabled version of the site. Please enable Javascript for this site to function properly.
Go to headerGo to navigationGo to searchGo to contentsGo to footer
In content section. Select this link to jump to navigation

Test-retest relative and absolute reliability of knee extensor strength measures and minimal detectable change

Article type: Research Article

Authors: Ferri-Morales, Asuncióna; b | Alegre, Luis M.b | Basco, Angela | Aguado, Xavierb

Affiliations: [a] Department of Nursing and Physiotherapy, University of Castilla-La Mancha, Toledo, Spain | [b] Biomechanics of Human Movement and Sport, Research, University of Castilla-La Mancha, Toledo, Spain

Note: [] Corresponding author: Asunción Ferri Morales, Departamento de Enfermería y Fisioterapia, Avda Carlos III s/n 45071 Toledo, Spain. Tel.: +34 925 268 800 ext 5820; Fax: +34 925 268 811; E-mail: asuncion.ferri@uclm.es

Keywords: Rehabilitation, reproducibility of results, dynamometry, torque

DOI: 10.3233/IES-130522

Journal: Isokinetics and Exercise Science, vol. 22, no. 1, pp. 17-26, 2014

Received 10 September 2013
|
Accepted 1 January 2014
|
Published: 24 January 2014
Get PDF open access

Abstract

BACKGROUND: Few studies have assessed the test-retest reliability of the isokinetic strength at 90°/s and the isometric parameters for knee extensors.

OBJECTIVES: To assess the reliability of isokinetic and isometric parameters of knee extensors, and to determine the smallest real difference between the test-retest measures.

METHODS: Knee extensor strength was measured twice, 4 to 5 days apart, using a Biodex dynamometer in forty subjects (12 men, 28 women). The protocols consisted of 5 concentric contractions at 90°/s and 5 isometric contractions.

RESULTS: For women, test-retest reliability was very high for isometric and isokinetic peak-torque (ICC[TeX:] _{c,1}> 0.9), moderate for work (ICC[TeX:] _{c,1}=0.82) and questionable for angle of peak torque (Angle-PT), mean Angle-PT and rate of torque development (RTD[TeX:] _{0-100 ms} (ICC < 0.67). The measurement errors were small for all variables, the SEM% ranged between 3.1% to 7.4%, and SRD% from 8.6% to 19.9%, except for RTD[TeX:] _{0-100 ms} that was the most variable (SEM% =16.4%; SRD=47.5%). No differences were found in Angle-PT and RTD[TeX:] _{0-100 ms} with regard to sex.

CONCLUSIONS: The isokinetic values obtained at 90°/s and isometric peak-torque for knee extensors are highly repeatable with a standardized test protocol and the SRD values can be used to detect real changes. Alternative strategies of analysis should be developed to improve reliability of Angle-PT and RTD[TeX:] _{0-100 ms}. Angle-PT and RTD[TeX:] _{0-100 ms} do not appear affected by gender.

Show more