The purpose of this preliminary study was to assess lumbar multifidus, erector spinae, and quadratus lum-borum muscle activity during lifts as measured by changes in transverse relaxation time (T2) from magnetic resonance imaging (MRI). Thirteen healthy adults performed dynamic squat, stoop, and asymmetric stoop lifts at a standard load, with each lift followed by MRI. Increase in T2 for the multifidus and erector spinae was greater for the stoop than squat. No difference in T2 increase was noted between the multifidus and erector spinae for the squat or stoop. Increase in T2 for the contralateral multifidus was less for the asymmetric stoop than stoop. Future research using MRI and other biomechanical techniques is needed to fully characterize lumbar muscle activity during lifts for various populations, settings, postures, and loads.
John M. Mayer (Corresponding Author) is with the School of Physical Therapy & Rehabilitation Sciences, College of Medicine, University of South Florida, Tampa, Florida. James E. Graves is with the College of Health, University of Utah, Salt Lake City, Utah. Todd M. Manini is with the Department of Aging and Geriatric Research, College of Medicine, University of Florida, Gainesville, Florida. James L. Nuzzo is with the School of Physical Therapy & Rehabilitation Sciences, College of Medicine, University of South Florida, Tampa, Florida. Lori L. Ploutz-Snyder is with Exercise Physiology and Countermeasures, Universities Space Research Association, NASA Johnson Space Center, Houston, Texas.