Activation of Scapular and Lumbopelvic Muscles During Core Exercises Executed on a Whole-Body Wobble Board

Context: Previous studies highlighted that exercises executed on unstable surfaces can yield important benefits to the function of the core musculature in rehabilitation settings, general conditioning settings, and athletic training when properly introduced within a periodized training schedule. No previous study has analyzed core-stability exercises executed in lying, quadruped, plank, and bridge positions on a whole-body wobble board (WWB) specifically designed to accommodate the exerciser's entire body and promote whole-body instability. We have designed a WWB allowed to roll in a plane perpendicular to its longitudinal axis to promote proactive and reactive activation of the core muscles with a transverse or diagonal line of action, which provides trunk and pelvic stability with low spine compression forces. Purpose: To determine the effect of the use of this newly designed WWB by assessing differences in core-muscle activity during core-stability exercises performed on the ground, in a stable condition, and on the WWB. Design: Controlled laboratory study. Setting: Research laboratory. Patients or Other Participants: Eighteen participants recruited from fitness centers. Intervention(s): The electromyographic (EMG) activity of lumbopelvic and scapular muscles has been recorded during core-stability exercises executed on the WWB (unstable condition) and on ground (stable condition). Main Outcome Measure(s): Mean and peak EMG activity were compared between stable and unstable condition with paired t tests or Wilcoxon signed-rank tests. Results: Overall, exercises performed on the WWB yielded significantly higher EMG activity in the serratus anterior and anterolateral abdominal muscles compared with the same exercises executed on the ground. Conversely, for the bird dog exercise, lower-back muscle activity was significantly higher on the ground. Conclusions: Compared with the ground, core-stability exercises executed on WWB constitute a simple and effective strategy to increase the activity level of the core muscles that control transverse-plane lumbopelvic and trunk stability, avoiding the use of external overload.