The use of ultrasound imaging by physical therapists is growing in popularity. This commentary has 2 aims. The first is to introduce the concept of rehabilitative ultrasound imaging (RUSI), provide a definition of the scope of this emerging tool in regard to the physical therapy profession, and describe how this relates to the larger field of medical ultrasound imaging. The second aim is to provide an overview of basic ultrasound imaging and instrumentation principles, including an understanding of the various modes and applications of the technology with respect to neuromusculoskeletal rehabilitation and in relation to other common imaging modalities.

J Orthop Sports Phys Ther. 2007:37(8):434-449; published online 30 May 2007. doi:10.2519/jospt.2007.2530

KEY WORDS: elastography, magnetic resonance imaging, rehabilitation, sonography

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To investigate the function of the transversus abdominis (TrA) and internal oblique (IO) muscles bilaterally during a simulated weight-bearing task using ultrasound imaging. BACKGROUND: An important aspect of neuromuscular control at the lumbopelvic region is stabilization. Biomechanical models have predicted that activation of transversely oriented muscles such as the TrA and IO muscles can stiffen the sacroiliac joints and actively stabilize the pelvis for weight-bearing. METHODS AND MEASURES: Nineteen healthy subjects were positioned in supine lying with their right heel against a footplate linked to a force transducer. Each subject performed a static simulated weight-bearing task of the right lower extremity. Ultrasound imaging was used to assess resultant changes in thickness of the IO and TrA muscles as well as the lateral slide of the anterior abdominal fascia on each side of the abdomen alternately. Muscle thickness and slide of the fascia were assessed at standardized force levels (0% and 25% of body weight). RESULTS: Substantial increases (P<.0001) in mean (±SD) thickness of the IO (18.5% ± 9.7%) and TrA (24.7% ± 17.5%) muscles during the weight-bearing task were measured. Lateral movement (slide) of the anterior abdominal fascia of the TrA muscle also occurred (mean ± SD, 1.3 ± 2.0 mm; P = .014) with weight-bearing. Changes in muscle thickness and amount of slide were similar for the left and right side of the abdomen (P≥.11). CONCLUSION: The findings are consistent with biomechanical models that predicted symmetrical activation of the deep transversely oriented lumbopelvic muscles in healthy subjects in response to a unilateral functional weight-bearing task. Ultrasound imaging as a measurement tool represents a noninvasive method for measuring abdominal muscle function in functional axial loading.  

J Orthop Sports Phys Ther. 2007:37(8):467-471; published online 30 May 2007. doi:10.2519/jospt.2007.2417

KEY WORDS: internal oblique muscle, lumbar stabilization, real-time ultrasound imaging, sonography, transversus abdominis muscle

STUDY DESIGN: Test-retest intrarater reliability study. OBJECTIVE: To examine reliability of abdominal musculature measurements across a broad range of conditions for a physical therapist newly trained in assessment using rehabilitative ultrasound imaging (RUSI). BACKGROUND: RUSI has previously been used to assess abdominal muscle function during a drawing-in maneuver of the anterior abdominal wall, and measurements conducted by an experienced assessor have been validated by comparison with magnetic resonance imaging. Few studies have examined the reliability of less experienced operators, and only in isolated measurement conditions. METHODS AND MEASURES: Nineteen subjects (11 female, 8 male) without a history of low back pain performed the abdominal drawing-in maneuver in a supine hook-lying position. RUSI was used bilaterally to assess the thickness of the internal oblique (IO) and transversus abdominis (TrA) muscles at rest and on contraction as well as changes in the length of the TrA muscle (indicated by slide of the anterior abdominal fascia). The reliability of a novice rater who received 8 hours of training was examined (a) across 3 measurements of the same ultrasound image, (b) across 3 separate ultrasound images (averaged for days and sides of abdomen), and (c) across 2 days (averaged for images and sides). RESULTS: Reliability of assessing muscle thickness was very high across 3 measurements of the same image (intrarater correlation coefficients [ICC_3,1] were all greater than 0.97), fair to high across 3 images (ICC_3,4 = 0.62-0.82), and fair to high across 2 days (ICC_3,6 = 0.63-0.85). Reliability of measuring the slide of the anterior abdominal fascia was very high across measurements from the same image (ICC_3,1 = 0.98) but very low across images (ICC_3,4 = 0.44) and across 2 days (ICC_3,6 = 0.36). CONCLUSIONS: High reliability of a novice rater was demonstrated for some measurement conditions. Measures of reliability for recapturing the image and repetition across days ranged from low to high. Inconsistencies in the pattern of results suggest that for a novice assessor using RUSI, training should be performed and reliability assessed for each abdominal muscle and measurement condition intended to be used for research and clinical practice.

J Orthop Sports Phys Ther. 2007:37(8):480-486; published online 30 May 2007. doi:10.2519/jospt.2007.2416

KEY WORDS: internal oblique muscle, real-time ultrasound imaging, sonography, transversus abdominis muscle

STUDY DESIGN: Case report. BACKGROUND: It has been suggested that altered neuromuscular control of the transversus abdominis and pelvic floor muscles may contribute to sacroiliac joint (SIJ) region pain and stress urinary incontinence. There are limited examples describing the evaluation and management of individuals with both SIJ region pain and stress urinary incontinence in the literature. This case report describes a patient with both conditions and details the integration of rehabilitative ultrasound imaging (RUSI) during physical therapy evaluation. CASE DESCRIPTION: A 35-year-old female soldier presented with a 6-week history of left buttock pain and 4-year history of stress urinary incontinence during activities that involved running, jumping, and fast walking. RUSI was used to supplement the physical assessment process, revealing altered motor control strategies of the transversus abdominis and pelvic floor muscles, and as a form of biofeedback during the rehabilitation process. OUTCOMES: After completing a rehabilitation program that incorporated principles of lumbar stabilization and pelvic floor muscle re-education, this patient was able to complete all physical activities in basic combat training without SIJ region pain or urinary leakage. DISCUSSION: This case demonstrates the importance of considering pelvic floor muscle dysfunction and training in a patient with primary complaints of SIJ region pain. It also highlights the potential role of RUSI as both an evaluation and biofeedback tool for the deep abdominal and pelvic floor muscles.

J Orthop Sports Phys Ther. 2007:37(8):499-504; published online 30 May 2007. doi:10.2519/jospt.2007.2538

KEY WORDS: biofeedback, pelvic floor muscles, transversus abdominis, sonography, spine