The Effect of Activation of Thoracolumbar Fascia on the Thickness of Abdominal Muscles; an Ultrasonographic Study

Spinal stabilization is crucial in maintaining healthy posture. Core muscle activation could be enhanced using thoracolumbar fascia for this stability.

Core, also called 'power house', is a muscular box built from abdominal muscles in the front, paraspinal, and gluteal muscles at the back, diaphragm at the top, and pelvic floor muscles at the bottom. Deep core muscles control intersegmental motion and respond to postural and extrinsic load changes and consist of transversus abdominis, internal oblique, multifidi and pelvic floor muscles.

Myofascial system links latissimus dorsi and gluteus maximus through thoracolumbar fascia causing tensegrity-like network in the whole body.

The aim of this study was to evaluate the changes in the thickness of abdominal muscles during activation of thoracolumbar fascia through contracting the gluteus maximus and latissimus dorsi muscles. The hypothesis was that the thickness of transversus abdominis and internal oblique would show greater increase when abdominal contraction was performed with simultaneous contraction of gluteus maximus and latissimus dorsi (bridge with arm extension) than that of abdominal contraction alone (abdominal hollowing) or abdominal contraction with simultaneous activation of only gluteus maximus (bridge).

Thirty healthy subjects (15 women, 15 men) were enrolled in this cross-sectional study. Thickness of transversus abdominis, internal oblique and external oblique muscles were evaluated using ultrasound at rest and during three exercise positions: abdominal hollowing in neutral spine, bridge, and bridge with isometric arm extension using ultrasound device equipped with 55 mm convex array transducer.