Can physical therapy students reliably measure the thickness of deep core musculature using handheld ultrasound...

The development of more compact and less expensive handheld ultrasound imaging (HHUI) devices allows for broader use in the medical field, including physical therapy. Traditional units are reliable when both a novice and an experienced rater are measuring the thickness of the transverse abdominis (TrA) and lumbar multifidus (LM) muscles. Physical therapists use ultrasound imaging of the TrA and LM to assist in the examination and treatment of lumbar pathology.

To identify the inter-rater reliability between novice and experienced physical therapist HHUI users when measuring the thickness of the LM and TrA muscles at rest and during contraction. A secondary objective was to determine the intra-rater reliability.

A cross-sectional observational design.

The experienced and novice physical therapists measured the thickness of both the LM at the L4 vertebral level and the TrA on an oblique axis with the Butterfly iQ + HHUI device. Muscle thickness was measured at rest and during isometric contractions. ICC values were calculated to determine the inter- and intra-rater reliability.

The study included 33 healthy adult participants, 19 females and 14 males, with a mean age of 34.6 years old. The inter-rater reliability between novice and experienced raters was good-to-excellent for the TrA and LM muscles. The intra-rater reliability was excellent for both raters.

Novice and experienced physical therapist can reliably use HHUI to measure the thickness of the LM and TrA. Results of this study may support the growing adoption of HHUI within physical therapy practice and education.