# Rehabilitative Ultrasound Imaging Evaluation in Physiotherapy: Piloting a Systematic Review
## 1 Introduction  
There is a lot of evidence on the use of ultrasound from an aspect that greatly diverges from that used by doctors, and for which the objectives are also different. The beginnings of the ultrasound technique, known as rehabilitative ultrasound imaging (RUSI), arose when ultrasound was used toassess tissue morphology rather than the pathological cross-sections [1]. The technique evolved during the 1980s at the hands of certain researchers [2], and underwent further development in subsequent years up to the first edition of the International Symposium of RUSI (Rehabilitative Ultrasound Imaging) [3] held in 2006 in San Antonio, Texas. During this time, the technique has evolved for its use in exploring the musculoskeletal tissues from a morphological and functional point of view in an attempt to explain activity disorders in some cases, and morphology with regard to the feelings of pain or disability in others.  
The second edition of this symposium was held in Madrid in 2016, and its conclusions [4] showed a greater scope of ultrasound implementation in physiotherapy.  
Musculoskeletal pain is the second highest cause of disability worldwide [5]. This fact has been supported since its first publication, and many factors influence its high incidence and prevalence of back pain, the anatomical region which is most affected. These factors include the increase in degenerative disorders such as osteoarthritis, inability to exercise, and increase in population age [6].  
The technical advancements in physiotherapy are essential for reflecting the work on a clinical level, and to be able to perform research in physiotherapy. Ultrasound is particularly relevant due to the high number of publications which validate it [7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36]. Currently, it is a tool recognized by the World Confederation of Physical Therapy (WCPT) at its congress in Las Vegas, Nevada (2009), and recognized on its website through an International Scientific Society known as the International Society in Electrophysical Agents in Physical Therapy (ISEAPT) that supports and endorses its use [37].  
During this entire period, up until now, only two systematic reviews of the RUSI technique on the lumbar pelvic area have been performed [38; 39], in which we can find different results, given that the first recognizes it as a valid technique for measuring the changes in the musculature in maximal and submaximal contractions, while the other speculates that it has to improve despite having good inter-tester validity studies.  
What is certain is that these systematic reviews were performed in 2009, and since then, the technique has not been reviewed again with almost a decade passing in-between them. The present study is confined to the lumbar region, although the complete review evaluates the lumbar pelvic region (lumbar, abdomen, and pelvic floor).  
The aims of this pilot study were two-fold: (1) To evaluate the scientific evidence on the RUSI technique in the lumbar region from 2012 to 2017 by performing a systematic review and meta-analysis when possible and (2) To coordinate the group of reviewers for the following phase in which a full systematic review of the lumbar pelvic area was conducted.