Real Time Ultrasound: An Objective Measure of Skeletal Muscle

Abstract

Objective measurement of muscle size is an important aspect of physiotherapy, but current clinical assessment methods are unreliable. Whilst not in widespread clinical use, real-time ultrasound has the potential to determine accurately both the linear dimensions and crosssectional area of skeletal muscle, providing evidence for the effectiveness of physiotherapy interventions. This systematic review of current literature was undertaken to investigate the validity and reliability of real-time ultrasound as an objective measure in physiotherapy practice, to discuss the implications for practice and to identify future research requirements. Eight current databases were searched for studies that measured skeletal muscle. Eleven articles were identified which specifically met the search criteria, and these were reviewed systematically. All of the articles found real-time ultrasound to be a valid and reliable tool for measuring skeletal muscle size under controlled conditions; however, confounding variables, such as fat, fascia orientation, muscle shape and pathology, were identified which may affect the validity of measurements in the general population. Further research is needed into deep and irregular muscles, and into the wider population, including obese, physically trained and symptomatic subjects to validate its use as a generalised tool. Furthermore, the use of a strict protocol was highlighted to ensure valid and reliable measurements in clinical practice.