ABSTRACT:: The American College of Sports Medicine and the United States Department of Health and Human Services advocate core training as a means to improve stability, reduce injury, and maintain mobility. There are countless exercises that target the primary core trunk muscles (abdominal and lumbar) with the aim of providing these benefits. However, it is unknown which exercises elicit the greatest activation thereby maximizing functional gains as well as peak performance. Thus our purpose was to determine whether integration core exercises that require activation of the distal trunk muscles (deltoid and gluteal) elicit greater activation of primary trunk muscles in comparison to isolation core exercises that only require activation of the proximal trunk muscles. Twenty participants, 10 men and 10 women, completed 16 randomly assigned exercises (for example, crunch, upper body extension, and hover variations). We measured muscle activity with surface electromyography of the anterior deltoid, rectus abdominus, external abdominal oblique, lumbar erector spinae, thoracic erector spinae, and gluteus maximus. Our results indicate that activation of the abdominal and lumbar muscles was greatest during the exercises that required deltoid and gluteal recruitment. In conclusion, when completing the core strength guidelines, an integrated routine that incorporates the activation of distal trunk musculature would be optimal in terms of maximizing strength, improving endurance, enhancing stability, reducing injury, and maintaining mobility.
Crunch in background, plank in foreground
Superman in background, bird-dog in foreground
*AD = anterior deltoid, RA = rectus abdominus, EO = external abdominal oblique, TE = thoracic erector spinae [the muscle that runs along your spine from your skull to your hip bone], LE = lumbar erector spinae [lower back muscle], GM = gluteus maximus.