Reliability and Validity of Static Knee Strength Measurements Obtained With a Chair-Fixed Dynamometer in Subjects With Hip or Knee Arthroplasty

• Published in: Archives of physical medicine and rehabilitation Vol. 86; no. 10; pp. 1998 - 2008
• Main Authors: Gagnon, Dany, Nadeau, Sylvie, Gravel, Denis, Robert, Josée, Bélanger, Dominique, Hilsenrath, Molly
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.10.2005; Elsevier
• Subjects: Aged; Arthroplasty; Arthroplasty, Replacement, Hip - rehabilitation; Arthroplasty, Replacement, Knee - rehabilitation; Biological and medical sciences; Female; Humans; Knee Joint - physiopathology; Male; Medical sciences; Middle Aged; Miscellaneous; Muscle Contraction - physiology; Muscle, Skeletal - physiopathology; Orthopedic surgery; Physical Therapy Modalities - instrumentation; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Range of Motion, Articular - physiology; Rehabilitation; Reliability and validity; Reproducibility of Results; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Reliability and validity; Arthroplasty; Rehabilitation; Knee; Statics; Prognosis; Chair; Reeducation; Ambulatory; Hospital; Measurement error; Human; Scanning electron microscopy; Physiotherapy; Static measurement; Hip; Standards; Dynamometer; Validity; Hip prosthesis; Orthopedic surgery; Treatment; Rehabilitation(human); Reliability; Strength
• ISSN: 0003-9993; 1532-821X
• DOI: 10.1016/j.apmr.2005.04.013

Gagnon D, Nadeau S, Gravel D, Robert J, Bélanger D, Hilsenrath M. Reliability and validity of static knee strength measurements obtained with a chair-fixed dynamometer in subjects with hip or knee arthroplasty. To evaluate the reliability (intertrial, interevaluator) and the concurrent validity of strength measurements obtained with a chair-fixed dynamometer and to recommend a clinical protocol that minimizes standard error of measurement (SEM). Within-session repeated measures of maximal static strength of knee flexors and extensors at 30° and 60° of flexion on the chair-fixed and Cybex dynamometers. Ambulatory physiotherapy department of a rehabilitation hospital. Convenience sample of 50 subjects with total hip (n=25) or knee (n=25) arthroplasty. Not applicable. Reliability was quantified by indices of dependability and corresponding SEMs estimated with the generalizability theory, whereas coefficients of correlation were used to assess the validity. Indices of dependability confirmed excellent intertrial (0.98–1.00) and a very good interevaluator (.92–.99) reliability for the strength measures obtained for different movements and positions. An average of 3 trials minimized the magnitude of the SEMs (>2Nm for all measurements). When comparing the strength values obtained with the Cybex dynamometer to those measured with the chair-fixed dynamometer, strongest relations were attained when the tested knee was positioned at 60° compared with 30° for subjects with a total knee (.78–.92 vs .87–.93) or hip (.73–.85 vs .86–.91) arthroplasty. A clinical protocol averaging 3 trials with the knee positioned at 60° after a familiarization period, both for knee flexors and extensors, performed by a trained therapist is recommended to minimize measurement errors on strength values measured with the chair-fixed dynamometer.