The aim of this study was to analyze the trunk muscular response during different variations of some of the most popular stabilization exercises: front-bridge, back-bridge, side-bridge, and bird-dog. Surface electromyography was bilaterally recorded from rectus abdominis, external and internal oblique and erector spinae during 25 variations of the aforementioned exercises. Compared to the conventional form of the front- and side-bridge, performing these exercises kneeling on a bench or with elbows extended reduced the muscular challenge. Conversely, performing the back-bridge with elbows extended elicited higher muscular activation than the conventional exercise. While bridge exercises with double leg support produced the highest activation levels in those muscles that counteracted gravity, single leg support while bridging increased the activation of the trunk rotators, especially internal oblique. The highest activation levels were found in three exercises: sagittal walkout in a front-bridge position, rolling from right side-bridge into front-bridge position, and side-bridge with single leg support on a BOSUTMbalance trainer. Although the exercises performed on unstable surfaces usually enhanced the muscle activation, performing the exercises on the BOSUTMbalance trainer did not always increase the trunk muscle activity. Overall, this information may be useful to guide fitness instructors and clinicians when establishing stabilization exercise progressions for the trunk musculature.
Electromyography; Exercise; Postural balance
