Open AccessIsometric strength measurements in children with arthritis: Reliability and relation to function
Author(s) -
Wessel Jean,
Kaup Cara,
Fan Jean,
Ehalt Ross,
Ellsworth Janet,
Speer Coral,
Tenove Pat,
Dombrosky Allison
Publication year - 1999
Publication title -
arthritis care & research
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/1529-0131(199908)12:4<238::aid-art2>3.0.co;2-i
Subject(s) - isometric exercise , intraclass correlation , inter rater reliability , medicine , grip strength , dynamometer , juvenile rheumatoid arthritis , physical therapy , reliability (semiconductor) , intra rater reliability , arthritis , physical medicine and rehabilitation , mathematics , rating scale , statistics , psychometrics , physics , clinical psychology , confidence interval , power (physics) , quantum mechanics , aerospace engineering , engineering
Objective To examine the reliability of testing strength in children withjuvenile arthritis (JA), and to determine the relationship betweenstrength and function. Methods Children with JA were tested for grip and pinch strength (n = 32). Isometric force produced by hip abductors and knee extensors wastested with a hand‐held dynamometer (n = 29). Two therapists bothperformed each of the tests twice so that intrarater and interraterreliability could be examined. Function was measured by means of theChildhood Health Assessment Questionnaire (CHAQ) and performance on a50‐meter run. Reliability was examined with intraclass correlations(ICC). The relationships of strength and function were determined withPearson and Spearman correlations. Results All measures demonstrated good intrarater (ICC = 0.92–0.97) andinterrater (ICC = 0.80–0.95) reliability. Grip strength and pinchwere correlated with the CHAQ (r = −0.45 and −0.33,respectively), while hip abduction and knee extension torque werecorrelated with rankings on the 50‐meter run (rho = −0.34 and−0.38, respectively). Conclusion Isometric strength can be reliably measured in children witharthritis in a clinical setting.