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Test-Retest Reliability of Isokinetic Knee Strength Measurements in Children Aged 8 to 10 Years.

Fagher, Kristina LU ; Fritzson, Annelie and Drake, Anna Maria LU (2016) In Sports Health
Abstract
BACKGROUND:



Isokinetic dynamometry is a useful tool to objectively assess muscle strength of children and adults in athletic and rehabilitative settings. This study examined test-retest reliability of isokinetic knee strength measurements in children aged 8 to 10 years and defined limits for the minimum difference (MD) in strength that indicates a clinically important change.

HYPOTHESIS:



Isokinetic knee strength measurements (using the Biodex System 4) in children will provide reliable results.

STUDY DESIGN:



Descriptive laboratory study.

METHODS:



In 22 healthy children, 5 maximal concentric (CON) knee extensor (KE) and knee flexor (KF)... (More)
BACKGROUND:



Isokinetic dynamometry is a useful tool to objectively assess muscle strength of children and adults in athletic and rehabilitative settings. This study examined test-retest reliability of isokinetic knee strength measurements in children aged 8 to 10 years and defined limits for the minimum difference (MD) in strength that indicates a clinically important change.

HYPOTHESIS:



Isokinetic knee strength measurements (using the Biodex System 4) in children will provide reliable results.

STUDY DESIGN:



Descriptive laboratory study.

METHODS:



In 22 healthy children, 5 maximal concentric (CON) knee extensor (KE) and knee flexor (KF) contractions at 2 angular velocities (60 deg/s and 180 deg/s) and 5 maximal eccentric (ECC) KE/KF contractions at 60 deg/s were assessed 7 days apart. The intraclass correlation coefficient (ICC2.1) was used to examine relative reliability, and the MD was calculated on the basis of standard error of measurement.

RESULTS:



ICCs for CON KE/KF peak torque measurements were fair to excellent (range, 0.49-0.81). The MD% values for CON KE and KF ranged from 31% to 37% at 60 deg/s and from 34% to 39% at 180 deg/s. ICCs in the ECC mode were good (range, 0.60-0.70), but associated MD% values were high (>50%). There was no systematic error for CON KE/KF and ECC KE strength measurements at 60 deg/s, but systematic error was found for all other measurements.

CONCLUSION:



The dynamometer provides a reliable analysis of isokinetic CON knee strength measurements at 60 deg/s in children aged 8 to 10 years. Measurements at 180 deg/s and in the ECC mode were not reliable, indicating a need for more familiarization prior to testing.

CLINICAL RELEVANCE:



The MD values may help clinicians to determine whether a change in knee strength is due to error or intervention. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Sports Health
publisher
SAGE Publications Inc.
external identifiers
  • pmid:26895853
  • scopus:84964850038
  • wos:000391283300008
ISSN
1941-0921
DOI
10.1177/1941738116632506
language
English
LU publication?
yes
id
351f02a1-cea3-46f1-b1b4-7176fee7b961 (old id 8825002)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/26895853?dopt=Abstract
date added to LUP
2016-03-03 13:21:04
date last changed
2017-09-18 11:28:40
@article{351f02a1-cea3-46f1-b1b4-7176fee7b961,
  abstract     = {BACKGROUND:<br/><br>
<br/><br>
Isokinetic dynamometry is a useful tool to objectively assess muscle strength of children and adults in athletic and rehabilitative settings. This study examined test-retest reliability of isokinetic knee strength measurements in children aged 8 to 10 years and defined limits for the minimum difference (MD) in strength that indicates a clinically important change.<br/><br>
HYPOTHESIS:<br/><br>
<br/><br>
Isokinetic knee strength measurements (using the Biodex System 4) in children will provide reliable results.<br/><br>
STUDY DESIGN:<br/><br>
<br/><br>
Descriptive laboratory study.<br/><br>
METHODS:<br/><br>
<br/><br>
In 22 healthy children, 5 maximal concentric (CON) knee extensor (KE) and knee flexor (KF) contractions at 2 angular velocities (60 deg/s and 180 deg/s) and 5 maximal eccentric (ECC) KE/KF contractions at 60 deg/s were assessed 7 days apart. The intraclass correlation coefficient (ICC2.1) was used to examine relative reliability, and the MD was calculated on the basis of standard error of measurement.<br/><br>
RESULTS:<br/><br>
<br/><br>
ICCs for CON KE/KF peak torque measurements were fair to excellent (range, 0.49-0.81). The MD% values for CON KE and KF ranged from 31% to 37% at 60 deg/s and from 34% to 39% at 180 deg/s. ICCs in the ECC mode were good (range, 0.60-0.70), but associated MD% values were high (&gt;50%). There was no systematic error for CON KE/KF and ECC KE strength measurements at 60 deg/s, but systematic error was found for all other measurements.<br/><br>
CONCLUSION:<br/><br>
<br/><br>
The dynamometer provides a reliable analysis of isokinetic CON knee strength measurements at 60 deg/s in children aged 8 to 10 years. Measurements at 180 deg/s and in the ECC mode were not reliable, indicating a need for more familiarization prior to testing.<br/><br>
CLINICAL RELEVANCE:<br/><br>
<br/><br>
The MD values may help clinicians to determine whether a change in knee strength is due to error or intervention.},
  author       = {Fagher, Kristina and Fritzson, Annelie and Drake, Anna Maria},
  issn         = {1941-0921},
  language     = {eng},
  month        = {02},
  publisher    = {SAGE Publications Inc.},
  series       = {Sports Health},
  title        = {Test-Retest Reliability of Isokinetic Knee Strength Measurements in Children Aged 8 to 10 Years.},
  url          = {http://dx.doi.org/10.1177/1941738116632506},
  year         = {2016},
}