Over the past decade, researchers have increasingly identified associations between neuromusculoskeletal disorders such as low back pain and underlying neuromuscular control deficits (Hodges and Moseley, 2003). However, reliable and valid non-invasive measurement strategies to assess neuromuscular control deficits that could be employed in a clinical setting have been scarce. Evidence for the use of ultrasound imaging as a strategy to assist with these patient populations is growing. The use of ultrasound technology for medical applications began in the 1950s and has proven to be an effective, safe, non-invasive, and relatively inexpensive tool for assessing morphologic characteristics and structural integrity of visceral organs and soft tissues. The use of ultrasound to assess muscle morphology and guide rehabilitation decision-making in physical therapy practice can be traced back to the late 1960s (Whittaker et al., 2007) and has been found to be reliable and valid (Koppenhaver et al., 2009) for specific muscles during particular movements. Over the last decade there has been rapid development of this technique with increased use both by clinicians and researchers.