Effect of Stretching on Thoracolumbar Fascia Injury and Movement Restriction in a Porcine Model

Objective: Stretching of fascia is an important component of manual and movement therapies. We previously showed that in pigs, a unilateral thoracolumbar fascia injury combined with movement restriction (hobble) produced contralateral loss of fascia mobility (shear strain during passive trunk flexion measured with ultrasound) similar to findings in human subjects with chronic low back pain. We now tested whether such abnormalities could be reversed by removing the hobble with or without daily stretching for 1 mo.

Design: Thirty pigs were randomized to control, injury, or injury + hobble for 8 wks. The hobble restricted hip extension ipsilateral to the injury. At week 8, the injury + hobble group was subdivided into continued hobble, removed hobble, and removed hobble + stretching (passively extending the hip for 10 min daily).

Results: Removing hobbles restored normal gait speed but did not restore fascia mobility. Daily passive stretching was not superior to removing hobbles, as there was no significant improvement in fascia mobility with either treatment group (removed hobble or stretching).

Conclusions: Reduced fascia mobility in response to injury and movement restriction worsens over time and persists even when movement is restored. Reversing fascia abnormalities may require either longer than 1 mo or a different treatment "dose" or modality.