SYNOPSIS: Magnetic resonance imaging (MRI) is capable of producing images in any anatomical plane, visualizing and analyzing a variety of tissue characteristics, as well as quantifying blood flow and metabolic functions. Although MRI details of compact bone and calcium are poor when compared to those taken with plain radiography or computed tomography, its high soft tissue contrast discrimination and multiplanar imaging capabilities are significant advantages. Musculoskeletal anatomy and neurovascular bundles are well delineated. The advent of MRI has revolutionized the clinicianís ability to confirm a proper diagnosis for musculoskeletal problems, which has led to more directed, specific rehabilitative protocols. However, the value of MRI to rehabilitative professionals has been even greater in its ability to identify serious, more uncommon pathologies, such as in those with underlying infection, fracture, or tumor, that require immediate care and are considered to be beyond their scope of practice. Furthermore, MRI, with its precise delineation of fat, muscle, and bone, is an ideal candidate for imaging of muscle disease or injury and has emerged as the method of choice for the detection of early cartilage wear in young patients, such as osteoarthritis. Finally, this imaging modality can avoid radiation exposure in a predominantly younger patient cohort commonly affected by musculoskeletal diseases. The aim of this paper is to consider how physical therapists may take advantage of the diagnostic value of MRI of the upper limb, while avoiding the pitfalls of misinterpretation of images as a result of technical issues, pathological changes, or normal variants.

J Orthop Sports Phys Ther 2011;41(11):861-872. doi:10.2519/jospt.2011.3833

KEY WORDS: MRI, musculoskeletal, radiology

STUDY DESIGN: Single-blinded quasi-experimental study. OBJECTIVE: To investigate the ability of elite football players with and without low back pain (LBP) to voluntarily draw-in the abdominal wall. BACKGROUND: While there has been considerable debate regarding the contribution of the transversus abdominis (TrA) muscle to control the lumbar spine and pelvis, there is evidence that retraining motor control of the deep trunk muscles is commensurate with decreases in LBP. Magnetic resonance imaging (MRI) has been used to assess the TrA muscle during the draw-in maneuver, with the contraction of the TrA muscle reducing the circumference of the trunk. Impairments in performance of the draw-in maneuver have been shown in people with LBP. METHODS: Forty-three elite players from a team in the Australian Football League were allocated to 3 groups: those with "no LBP," "a history of LBP but no current LBP," or "current LBP." MRI was used to image the cross-sectional area (CSA) of the trunk at the level of the L3-4 disc at the start and end of the draw-in maneuver. RESULTS: There was a significant decrease in the CSA of the trunk with the performance of the draw-in maneuver (P<.001). Subjects in the "no LBP" group were better able to "draw-in" the abdominal wall than subjects with current LBP (P = .015). CONCLUSIONS: This study provides evidence of an altered ability to draw-in the abdominal wall in footballers with current LBP. Retraining contraction of the TrA muscle may constitute one part of an exercise-therapy approach for athletes with current LBP.

J Orthop Sports Phys Ther 2010;40(1):4-10, Epub 3 December 2009. doi:10.2519/jospt.2010.3177

KEY WORDS: abdomen, lumbar spine, MRI