Effects of a 16-week Pilates exercises training program for isometric trunk extension and flexion strength

To evaluate the effects of Pilates exercises designed to improve isometric trunk extension and flexion strength of muscles in women with chronic low back pain (cLBP).

Female volunteers with cLBP were divided into an experimental group (EG; n = 27) and a control group (CG; n = 27).

Pilates exercises were performed twice per week by the EG; the duration of each session was 60 min. The program lasted for 16 weeks; thus patients underwent a total of 32 exercise sessions.

The maximum isometric waist bending strength of the EG had improved significantly (p = 0.001) after 16 weeks of the Pilates program. The results of trunk flexion muscle endurance tests significantly depended on the trunk extension muscle endurance before the intervention, and at 1 month (r = 0.723, p < 0.001) and 2 months (r = 0.779, p < 0.001) after the Pilates exercise program. At the end of the 16-week exercise program, cLBP intensity decreased by 2.01 ± 0.8 (p < 0.05) in the EG, and this reduction persisted for 1 month after completion of the program.

At 1 and 2 months after cessation of the Pilates exercise program the pain intensified and the functional state deteriorated much faster than the maximum trunk muscle strength. Therefore, it can be concluded that, to decrease pain and improve functional condition, regular exercise (and not only improved strength and endurance) is required. We established that, although the 16-week lumbar stabilization exercise program increased isometric trunk extension and flexion strength and this increase in strength persisted for 2 months, decreased LBP and improved functional condition endured for only 1 month.