Evaluation of a New Device for Measuring Responses to Posteroanterior Forces in a Patient Population, Part 1: Reliability Testing

• Published in: Physical therapy Vol. 76; no. 2; pp. 158 - 165
• Main Authors: Latimer, Jane, Goodsell, Michalene M, Lee, Michael, Maher, Christopher G, Wilkinson, Barry N, Moran, Carmen C
• Format: Journal Article
• Language: English
• Published: United States American Physical Therapy Association 01.02.1996; Oxford University Press
• Subjects: Adult; Back; Biomechanical Phenomena; Female; Humans; Instruments; Low Back Pain - physiopathology; Lumbar Vertebrae - physiopathology; Male; Measurement; Middle Aged; Pain; Physical Therapy Modalities - instrumentation; Reliability; Reproducibility of Results
• ISSN: 0031-9023; 1538-6724
• DOI: 10.1093/ptj/76.2.158

This study determined the test-retest reliability of measurements of responses to posteroanterior (PA) forces made using a recently developed instrument. Twenty-two subjects with nonspecific low back pain participated. The length of the low- stiffness or "toe" region and the slope of the linear portion of the force-displacement curve were measured on two occasions. Reliability of repeated measurements was evaluated by intraclass correlation coefficients and percentage-of-agreement scores. The presence of a systematic change in the response to PA forces was evaluated by a paired-samples t test. High reliability coefficients were obtained for both indices of the response to PA forces. The t test revealed no systematic change with repeated testing. The new device provides highly reliable measurement of the lumbar PA force-displacement relationship and may prove useful in evaluating theories that have suggested a relationship between spinal symptoms and abnormal PA stiffness.