Pilates instruction affects stability and muscle recruitment during the long stretch exercise.

Purpose: To examine pelvic stability with and without instruction regarding the voluntary recruitment of the 'powerhouse' muscles during a long stretch exercise on the Pilates Reformer.

Scope: Evaluation of the muscle activity and pelvic stability during a Pilates exercise of 12 physically active volunteers. Volunteers performed five repetitions of the long stretch in sets of two, one with and one without instruction regarding the voluntary recruitment of the powerhouse muscles. Electromyography of the external oblique (EO), multifidus (MU), gluteus maximus (GM) and adductor longus (AL) muscles and pelvic angle stability were recorded.

Conclusion: When asked to perform the exercise with instruction regarding the voluntary recruitment of the powerhouse muscles, all muscles were more activated, with the exception of the EO. In the voluntary recruitment situation, lumbopelvic stability, as measured by the coefficient of variation of the pelvic angle, was higher than in instances without instruction. Lumbopelvic stability undergoes changes with and without instruction regarding the voluntary recruitment of the powerhouse muscles when the long stretch exercise is performed on a Reformer.