STUDY DESIGN: Cross-sectional design. OBJECTIVES: To investigate lumbar multifidus (LM) thickness differences, using ultrasound imaging in people during remission from recurrent low back pain (LBP) and healthy participants, during the following lower extremity movements: (1) active straight leg raise (ASLR), (2) crook-lying active leg raise (CLR), and (3) prone straight leg raise (PSLR). BACKGROUND: ASLR, CLR, and PSLR are used clinically to challenge the ability of the trunk muscles to control spinal motion in people with LBP, and it is believed that decreased LM activity is related to altered spinal control in this population. However, it is unclear whether LM behavior differs between healthy individuals and people with recurrent LBP during symptom remission in such tasks. METHODS: The present study used ultrasound imaging to measure LM percentage thickness change parasagitally at the L4-5 and L5-S1 levels in people with recurrent LBP during symptom remission and in healthy participants, during the ASLR, CLR, and PSLR tasks. RESULTS: LM percentage thickness change was greater in the recurrent LBP group than in healthy participants during the PSLR task (P<.01) and greater in both groups during the PSLR than the ASLR and CLR tasks (P<.01). LM percentage thickness change was greatest at L4-5 in both groups (P<.01) and during all tasks (P≤.02). No difference was found in LM percentage thickness change between groups in either the ASLR (P = .70) or CLR (P = .69) task. CONCLUSIONS: These data suggest that, during symptom remission, individuals with recurrent LBP, compared to healthy individuals, may have greater activity in at least some parts of the LM. Further investigation is required to determine whether the LM percentage thickness change observed in this study may be explained by differential changes in deep and/or superficial fibers of LM activity. This observation may have implications for clinical practice, but requires further investigation.

J Orthop Sports Phys Ther 2011;41(3):155-164, Epub 4 January 2011. doi:10.2519/jospt.2011.3410

KEY WORDS: lumbar spine, spinal control, stabilization, ultrasound imaging

SYNOPSIS: Interest in rehabilitative ultrasound imaging (RUSI) of the posterior paraspinal muscles is growing, along with the body of literature to support integration of this technique into routine physical therapy practice. This clinical commentary reviews how RUSI can be used as an evaluative and treatment tool, and proposes guidelines for its use for the posterior muscles of the lumbar and cervical regions. Both quantitative and qualitative applications are described, as well as measurement reliability and validity. Measurement of morphological characteristics of the muscles (morphometry) in healthy populations and people with spinal pathology are described. Preliminary normal reference data exist for measurements of cross-sectional area (CSA), linear dimensions (muscle depth/thickness and width), and shape ratios. Compared to individuals without low back pain, changes in muscles' size at rest and during the contracted state have been observed using RUSI in people with spinal pathology. Visual observation of the image during contraction indicates that RUSI may be a valuable biofeedback tool. Further investigation of many of these observations is required using controlled studies to provide conclusive evidence that RUSI enhances clinical practice.

J Orthop Sports Phys Ther. 2007;37(10):581-595, published online 29 August 2007. doi: 10.2519/jospt.2007.2599

KEY WORDS: cervical muscles, lumbar muscles, lumbar spine, neck, morphometry, sonography

J Orthop Sports Phys Ther. 2007:37(8):487-498; published online 20 June 2007. doi:10.2519/jospt.2007.2548

KEY WORDS: levator ani, sonography, therapeutic exercise, transabdominal ultrasound imaging, transperineal ultrasound imaging

Rehabilitative ultrasound imaging (RUSI) of the abdominal muscles is increasingly being used in the management of conditions involving musculoskeletal dysfunctions associated with the abdominal muscles, including certain types of low back and pelvic pain. This commentary provides an overview of current concepts and evidence related to RUSI of the abdominal musculature, including issues addressing the potential role of ultrasound imaging in the assessment and training of these muscles. Both quantitative and qualitative aspects associated with clinical and research applications are considered, as are the possible limitations related to the interpretation of measurements made with RUSI. Research to date has utilized a range of methodological approaches, including different transducer placements and imaging techniques. The pros and cons of the various methods are discussed, and guidelines for future investigations are presented. Potential implications and opportunities for clinical use of RUSI to enhance evidence-based practice are outlined, as are suggestions for future research to further clarify the possible role of RUSI in the evaluation and treatment of abdominal muscular morphology and function.

J Orthop Sports Phys Ther. 2007:37(8):450-466; published online 30 May 2007. doi:10.2519/jospt.2007.2558

KEY WORDS: morphometry, obliquus internus abdominis, rectus abdominis, sonography, transversus abdominis

Real-time ultrasound imaging provides an unrivalled opportunity to observe muscle morphology and contraction. This has obvious potential for clinical practice and the tool is beginning to be adopted into physical therapy. The implementation of ultrasound imaging has become particularly widespread for assessment of size and activation of deep trunk muscles, such as the transversus abdominis and lumbar multifidus, and for assessment of the pelvic floor muscles. The obvious benefit for these areas is that ultrasound permits observation of muscles that are difficult to assess through noninvasive means. This realization of the clinical potential of ultrasound imaging has been paralleled by an explosion of clinical and physiological research. However, despite the enthusiasm for utilization of ultrasound imaging, a question that is critical to address is whether ultrasound can actually improve rehabilitation.

J Orthop Sports Phys Ther. 2005; 35(6):333-337. doi:10.2519/jospt.2005.0106

Key Words: ultrasound imaging, rehabilitation