Pressler JM, Heiss DG, Buford JA, Chidley JV; The Ohio State University, Columbus, OH, USA. Presslj@ucmail.uc.edu.

PURPOSE: The first purpose of this study was to establish baseline intra-rater reliability data of a non-ultrasound technician to image the multifidus muscle. The second purpose was to compare our findings with previous reports of symmetry and ovoid shape in the young, female population. SUBJECTS: 30 young, healthy, female subjects aged 20 to 30 (age = 23 ± 2 yrs, mass = 63.1 ± 9.2 kg, height = 1.63 ± 0.06 m, body fat = 31 ± 5.5 %) from a sample of convenience participated. The first fourteen subjects also served as the sample for the intra-rater reliability study. METHODS: The protocol established by Hides et al. (1995) was employed. Subjects were positioned in prone on a plinth with the hips flexed 35 degrees below horizontal in order to flatten the lumbar lordosis. The bilateral multifidus muscles at the level of S1 were imaged, measured, and stored on the ultrasound unit. The first fourteen subjects returned within three days and the procedure was repeated. ANALYSIS: The intra-class correlation coefficient (ICC, model 3,1) was used for all analyses to evaluate between-day repeatability and within-day symmetry of the multifidus at S1. RESULTS: Intra-rater, between-day, reliability for the left multifidus was 0.73 (SEM of 0.37cm²) and the right multifidus was 0.79 (SEM of 0.32cm²). Symmetry between left and right multifidus muscles was 0.94 (SEM 0.14cm²). The shape of the multifidus muscles was ovoid in this population. CONCLUSION: Baseline data supports the ability of a physical therapist to learn to reliably image the multifidus muscle. The findings of symmetry and ovoid shape of the multifidi in the young, healthy female are consistent with reports from similar studies. Future clinicians may use ultrasound technology as a method to assess multifidus cross-sectional area or for visual feedback during multifidus strengthening exercises. FUNDING SOURCE: The Rosita Schiller Research Award.

Copyright 2004 by the American Physical Therapy Association

Reprint Information
Requests for reprints should be directed to the corresponding author of the article. Students and other academic customers may receive permission to reprint copyrighted material from Physical Therapy by contacting the Copyright Clearance Center Inc, 222 Rosewood Dr, Danvers, MA 01923. Similar inquiries by all others should be made to the APTA Editorial Office, Attn: Physical Therapy.