Is thoracolumbar fascia shear‐wave modulus affected by active and passive knee flexion?

Abstract

The purpose of this study was to examine the effect of passive and active knee flexion efforts on the stiffness of the thoracolumbar (TLF), semitendinosus (STF), and semimembranosus fascia (SMF). Fourteen young healthy males participated in this study. Using ultrasound shear‐wave elastography, fascia elastic modulus was measured at rest (passive condition) and during submaximal isometric knee flexion efforts (active condition) with the hip at neutral position and the knee flexed at 0°, 45°, and 90°. Analysis of variance designs indicated that when the knee was passively extended from 90° to 0°, shear modulus of the TLF, SMF, and STF increased significantly ( p < 0.05). Similarly, active knee flexion contractions caused a significant increase in TLF, SMF, and STF shear modulus ( p < 0.001). Compared to hamstring fascia, the TLF showed greater thickness but a lower shear modulus ( p < 0.05) while STF modulus was greater compared that to SMF during active contraction ( p < 0.05). These results indicate that exercising the hamstring muscles can remotely influence the stiffness of the fascia which surrounds the lumbar area.

Abstract

• Stiffness of the thoracolumbar fascia and the hamstrings increases as the knee passively moves from flexion to extension as well as during active knee flexion contractions.

• Fascia stiffness varies between lumbar and posterior thigh area as well as between the hamstrings themselves.

• Hamstring exercises influence the stiffness of the fascia not only of the involved musculature but also the lumbar region fascia.