A comparison of intersegmental joint dynamics to isokinetic dynamometer measurements

Kenton R Kaufman, Kai Nan An, Edmund Y S Chao

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

This study quantified the errors associated with measurements obtained using an isokinetic dynamometer for knee evaluation at 60° and 180° s-1. Five normal subjects were tested. A triaxial electrogoniometer was used to measure the kinematics. A custom-designed load cell was used to measure the three orthogonal components of the reaction force applied by the isokinetic dynamometer to the leg. The inverse dynamics problem was solved to obtain the intersegmental dynamics at the knee joint. These data were compared to those obtained from the isokinetic dynamometer. The results indicate that the knee motion recorded by the isokinetic dynamometer was in error by 7-9° during flexion and 10-13° during extension. The isokinetic dynamometer recorded knee flexions which were less than actual during the flexion portion of the exercise and greater than actual during extension. The duration of constant velocity was limited based on the speed selected. The knee moment was in error by 5 Nm during flexion and 25-29 Nm during extension. The use of a gravity correction factor reduced the knee moment error during extension but increased it during flexion.

Original languageEnglish (US)
JournalJournal of Biomechanics
Volume28
Issue number10
DOIs
StatePublished - 1995

Fingerprint

Dynamometers
Knee
Joints
Gravitation
Knee Joint
Biomechanical Phenomena
Leg
Kinematics

Keywords

  • Inverse dynamics
  • Isokinetic dynamometer
  • Kinematics
  • Kinetics
  • Knee

ASJC Scopus subject areas

  • Biophysics
  • Biomedical Engineering
  • Orthopedics and Sports Medicine
  • Rehabilitation

Cite this

A comparison of intersegmental joint dynamics to isokinetic dynamometer measurements. / Kaufman, Kenton R; An, Kai Nan; Chao, Edmund Y S.

In: Journal of Biomechanics, Vol. 28, No. 10, 1995.

Research output: Contribution to journalArticle

@article{c564c655f1d24c02a329019ac88943ad,
title = "A comparison of intersegmental joint dynamics to isokinetic dynamometer measurements",
abstract = "This study quantified the errors associated with measurements obtained using an isokinetic dynamometer for knee evaluation at 60° and 180° s-1. Five normal subjects were tested. A triaxial electrogoniometer was used to measure the kinematics. A custom-designed load cell was used to measure the three orthogonal components of the reaction force applied by the isokinetic dynamometer to the leg. The inverse dynamics problem was solved to obtain the intersegmental dynamics at the knee joint. These data were compared to those obtained from the isokinetic dynamometer. The results indicate that the knee motion recorded by the isokinetic dynamometer was in error by 7-9° during flexion and 10-13° during extension. The isokinetic dynamometer recorded knee flexions which were less than actual during the flexion portion of the exercise and greater than actual during extension. The duration of constant velocity was limited based on the speed selected. The knee moment was in error by 5 Nm during flexion and 25-29 Nm during extension. The use of a gravity correction factor reduced the knee moment error during extension but increased it during flexion.",
keywords = "Inverse dynamics, Isokinetic dynamometer, Kinematics, Kinetics, Knee",
author = "Kaufman, {Kenton R} and An, {Kai Nan} and Chao, {Edmund Y S}",
year = "1995",
doi = "10.1016/0021-9290(94)00176-5",
language = "English (US)",
volume = "28",
journal = "Journal of Biomechanics",
issn = "0021-9290",
publisher = "Elsevier Limited",
number = "10",

}

TY - JOUR

T1 - A comparison of intersegmental joint dynamics to isokinetic dynamometer measurements

AU - Kaufman, Kenton R

AU - An, Kai Nan

AU - Chao, Edmund Y S

PY - 1995

Y1 - 1995

N2 - This study quantified the errors associated with measurements obtained using an isokinetic dynamometer for knee evaluation at 60° and 180° s-1. Five normal subjects were tested. A triaxial electrogoniometer was used to measure the kinematics. A custom-designed load cell was used to measure the three orthogonal components of the reaction force applied by the isokinetic dynamometer to the leg. The inverse dynamics problem was solved to obtain the intersegmental dynamics at the knee joint. These data were compared to those obtained from the isokinetic dynamometer. The results indicate that the knee motion recorded by the isokinetic dynamometer was in error by 7-9° during flexion and 10-13° during extension. The isokinetic dynamometer recorded knee flexions which were less than actual during the flexion portion of the exercise and greater than actual during extension. The duration of constant velocity was limited based on the speed selected. The knee moment was in error by 5 Nm during flexion and 25-29 Nm during extension. The use of a gravity correction factor reduced the knee moment error during extension but increased it during flexion.

AB - This study quantified the errors associated with measurements obtained using an isokinetic dynamometer for knee evaluation at 60° and 180° s-1. Five normal subjects were tested. A triaxial electrogoniometer was used to measure the kinematics. A custom-designed load cell was used to measure the three orthogonal components of the reaction force applied by the isokinetic dynamometer to the leg. The inverse dynamics problem was solved to obtain the intersegmental dynamics at the knee joint. These data were compared to those obtained from the isokinetic dynamometer. The results indicate that the knee motion recorded by the isokinetic dynamometer was in error by 7-9° during flexion and 10-13° during extension. The isokinetic dynamometer recorded knee flexions which were less than actual during the flexion portion of the exercise and greater than actual during extension. The duration of constant velocity was limited based on the speed selected. The knee moment was in error by 5 Nm during flexion and 25-29 Nm during extension. The use of a gravity correction factor reduced the knee moment error during extension but increased it during flexion.

KW - Inverse dynamics

KW - Isokinetic dynamometer

KW - Kinematics

KW - Kinetics

KW - Knee

UR - http://www.scopus.com/inward/record.url?scp=0029144808&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029144808&partnerID=8YFLogxK

U2 - 10.1016/0021-9290(94)00176-5

DO - 10.1016/0021-9290(94)00176-5

M3 - Article

C2 - 8550643

AN - SCOPUS:0029144808

VL - 28

JO - Journal of Biomechanics

JF - Journal of Biomechanics

SN - 0021-9290

IS - 10

ER -