Test-Retest Reliability of Isokinetic Dynamometry for the Assessment of Spasticity of the Knee Flexors and Knee Extensors in Children With Cerebral Palsy
Accepted 13 January 2006.
Abstract
Pierce SR, Lauer RT, Shewokis PA, Rubertone JA, Orlin MN. Test-retest reliability of isokinetic dynamometry for the assessment of spasticity of the knee flexors and knee extensors in children with cerebral palsy.
Objective
To assess test-retest reliability of the peak resistance torque and slope of work methods of spasticity measurement of the knee flexors and extensors in children with cerebral palsy (CP).
Design
Test-retest reliability study.
Setting
Pediatric orthopedic hospital.
Participants
Fifteen children with CP.
Intervention
Knee extensor and flexor spasticity was assessed with an isokinetic dynamometer using passive movements at 15°, 90°, and 180°/s taken 1 hour apart.
Main Outcome Measures
Peak resistive torque and work were calculated. The relative and absolute test-retest reliability was calculated by using intraclass correlation coefficients (ICCs) and Bland-Altman plots, respectively.
Results
Relative reliability was good (ICC>.75) for slope-of-work and peak resistance torque measurements at a velocity of 180°/s, whereas reliability of peak torque measurements was decreased (ICC<.51) at slower velocities for both muscle groups. The 95% limits of agreement of Bland-Altman plots contained most data points for both methods, but the width of the limits of agreement were wide.
Conclusions
The measurement of spasticity of the knee extensors and flexors in children with CP using peak-resistance torque at 180°/s and the slope of work method has acceptable relative test-retest reliability. However, the absolute reliability of spasticity data should be considered cautiously.
aResearch Department, Shriners Hospitals for Children in Philadelphia, Philadelphia, PA
bCollege of Nursing and Health Professions, Drexel University, Philadelphia, PA
cHahnemann Programs in Rehabilitation Sciences, Drexel University, Philadelphia, PA
dDepartment of Physical Therapy, Temple University, Philadelphia, PA
eInstitute for Physical Therapy Education, Widener University, Chester, PA
Reprint requests to Samuel R. Pierce, PT, MS, NCS, Research Department, Shriners Hospitals for Children, 3551 N Broad St, Philadelphia, PA 19140
Supported by Shriners Hospitals for Children (grant no. 8520).
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated.
ABSTRACT