Rehabilitative Ultrasound Imaging: Understanding the Technology and Its Applications

Abstract

From an historical perspective, ultrasound imaging (USI) has been used for medical purposes since the 1950s. The primary use of USI continues to be for traditional radiological goals, which consider the morphological characteristics and structural integrity of various organs and tissues. However, as the technology has been embraced as a safe, portable, objective, and relatively inexpensive means of examination, the ingenuity and diversity of applications has extended beyond these realms.Ultrasound imaging related to musculoskeletal rehabilitation has been developing rapidly since the 1980s. The first report of muscle imaging linked to rehabilitation was in 1968, when Ikai and Fukunaga 63 related the size of the upper arm muscles to strength. However, it was the work of Dr Archie Young and colleagues at the University of Oxford in the 1980s that sowed the seeds for the use of USI by physical therapists. A striking finding of their work was how dramatic limb muscle wasting is underestimated with a tape measure.144 Several studies of the quadriceps muscle followed, including investigation of the effect of knee joint injury, t SynopSiS: 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. doi:10.2519/jospt.2007 for a review). This early research used compound B-scanning, which enabled whole cross sections of large muscles to be captured, because the image could be built up as the transducer was moved over the skin. The compound technique, which was expensive, was phased out as a routine tool and replaced by real-time USI (definitions are provided in the appenDix) both in general medical and musculoskeletal settings.A recent (1990s) resurgence in the interest of rehabilitative applications of USI has been seen amongst clinical therapists. This stems from a series of studies in which USI was used to detect atrophy of the lumbar multifidus (isolated to the side and spinal level of symptoms) in individuals with acute low back pain (LBP), 51 as well as to determine that recovery of this muscle was not automatic when pain subsided, 49 thus required specific training to reduce risk of future episodes. 47 In addition, these studies

Sports hernias: a systematic literature review

“…To date the most effective use of various imaging techniques has been to exclude other groin-region injuries. Innovative rehabilitative ultrasonography imaging methods may have considerable potential for directing conservative and post-surgical sports hernia treatment 66 86 88…”

Reliability of Ultrasound Imaging for the Assessment of Lumbar Multifidi Thickness in Older Adults With Chronic Low Back Pain

“…Ultrasound imaging (USI), which uses reflected sound waves to create gray-scale images, 25 is emerging as a safe and cost-effective clinical tool. USI offers practitioners the ability to perform not only direct assessments of posterior trunk muscle function but also assessments of muscle size in the outpatient setting.…”

“…25,29,33 Parasagittal imaging is used to assess multifidus thickness and activity, 27,29 while transverse imaging is used to assess multifidus cross-sectional area. 26,32 USI measurement techniques rely on the ability to accurately identify multifidi fascial lines, which are hyperechoic (appear bright white) when compared to adjacent muscle tissue, which is more hypoechoic (appears darker).…”

Sonographic Measures of the Gluteus Medius, Gluteus Minimus, and Vastus Medialis Muscles

“…17 Specifically, rehabilitative USI refers to the USI procedures used by physiotherapists to evaluate the morphology and behavior of muscle and its related soft tissues, to provide biofeedback about muscle behavior during restoration of function, and to carry out research aimed at informing clinical practice. 17 To date, USI has been used to investigate a variety of muscles and to address a diversity of research questions.…”

“…17 Specifically, rehabilitative USI refers to the USI procedures used by physiotherapists to evaluate the morphology and behavior of muscle and its related soft tissues, to provide biofeedback about muscle behavior during restoration of function, and to carry out research aimed at informing clinical practice. 17 To date, USI has been used to investigate a variety of muscles and to address a diversity of research questions. Sonography has been shown to be a valid method (primarily in healthy adults under resting conditions) to measure the morphology of the trunk (abdominal and lumbar multifidus), 2,3 as well as a range of other muscles, 5,8,10,11 through comparison to magnetic resonance imaging.…”