Background It has been shown that patients with low back pain present morphologic changes and dysfunctions in abdominal muscles, such as the transversus abdominis muscle (TrA). Furthermore, ultrasound imaging is effective and reliable to study these changes. Studies suggest that stabilisation exercises are effective to resolve those kinds of musculoskeletal diseases.

The aim was to evaluate the effects of a supervised exercise therapy programme on abdominal muscle recruitment amongst clothing manufacturing workers, as well as on low back pain and lumbar disability.

Methods The study was conducted at a textile cooperative facility in Galicia (Spain). It was used a quasi-experimental design, with measurements taken before and after 15 sessions. Thirteen women were included.

Outcome measures ultrasound measurement of abdominal muscles (TrA, obliques and rectus abdominis) recruitment (morphological and functional study) with a convex probe of 2–5 MHz and with a Sonosite M-Turbo Fujifilm equipment, visual analogue scale (VAS), Roland-Morris (RM), SF-36 questionnaire. Exercises were performed during 80 min, once per week. They included breathing, stabilisation, flexibility, neural movilization, strengthening and relaxation exercises. Statistical analysis was carried out using Student’s T-test and Wilcoxon’s test. The study was approved by the Ethics Committee (CE 09/2014).

Results Compared with the baseline, no evidence of morphological changes related with the thickness of the abdominal muscles in rest was found. Functional improvement in this musculature such as the synergy within the pelvic floor, in the analytical contraction of the TrA, and in active straight leg raising test were indeed found.

After the exercise program, significant decrease was observed in VAS for low back (p=0,049) and in the RM (p=0,042). All SF-36 dimensions presented an improvement, but in physical dimensions this improvement was more significant: Physical Component Summary (p=0,046).

Conclusions Exercise therapy program was beneficial to improve abdominal muscles function, to decrease intensity of pain and low back disability, and to improve the perceived Health Related Quality of Life. It is important to remark the limitation of the study such as a quite small sample and a not so experimental design.