Abdominal muscle activation: An EMG study of the Sahrmann five-level core stability test.

Background: Sahrmann five-level core stability test protocol has been used to evaluate the ability of the core muscles to stabilize the spine. However, validation studies on the Sahrmann protocol are limited.

Objective: The purpose of this study was to compare the different levels of Sahrmann five-level core stability (levels 1-5) on the muscle activity of rectus abdominis (RA), external oblique (EO), and transverse abdominis/internal oblique (TrA/IO).