If you've taken any ballet at all, you've probably heard your instructor reminding the class to "tighten the core" or "pull up the abdominals/pelvic floor". This correction is so common that this internet list has collected some of the most creative (and hilarious) phrasings for this advice.
In all seriousness, there IS a reason why the lower abdominal muscles or transverse abdominis muscles are also known as "the dancer abs", but many dancers (especially adult or recreational students) are somewhat confused by what is meant by "engaging the core". What exactly IS this core we speak of and how do we use it? This post is intended to give a brief and general overview of the core from a recreational dancer's point of view as well as to provide a few useful resources for finding and working your own ballet core. Developing a strong core and the body awareness of how to effectively activate and use these muscles will greatly assist in your progress in ballet technique. Although we tend to concentrate on what the arms and legs (and heads and shoulders) are doing while dancing, it's the core activation that holds it all together!
For ballet purposes, "the core" refers to the cylindrical support of the pelvic region via the interplay of several groups of deep muscles that stabilize this area. The transverse abdominis muscles are located in the lower front of the abdomen, below than the navel and between the hip bones (i.e., not the "six-pack" upper abs or rectus abdominis muscles found higher on the torso). The pelvic floor literally forms the muscular "floor" of your inner abdominal cavity; it runs from the pelvic bone in your genital area to between the sitz bones, and back to the tailbone area (the pelvic floor muscles are those that you use in Kegel exercises or tighten to stop the flow of urine). Around the lower back of the abdomen are a couple of small deep muscle groups known as the multifidus and the quadratus lumborum that provide support in and around the spine and sacrum area. Because these muscles tend to be smaller and located more deeply inside the body (they are usually located underneath other muscles), identifying these muscles and learning how to properly activate them may require a little practice.
Classical Pilates instruction is one of the most effective ways to learn core activation and strengthening of these muscles, and a personal Pilates routine is an important part of many professional dancers' routine maintenance. It is true that quality Pilates classes/instruction can be difficult to find and/or tend to be quite expensive. However, books, videos, and the internet can provide helpful insights. As with ballet, there is simply no substitute for the well-trained eye and corrections of a well trained professional instructor, but here in the real world of adults with full schedules and limited resources, self-education can get you started.
The website DoYogaWithMe.com offers a wide range of free yoga, stretching, and Pilates videos that you can use for home workouts, but one of the most valuable areas on this site is a resource section titled "Yoga Anatomy" that includes a series of eight short videos that explain the location and activation of the core muscles and lead you through step-by-step exercises that will help you find and learn to use these muscles together with proper alignment and breathing. The info video on the five Pilates principles is a good "next step" in putting that new core awareness into practice. Classic Pilates mat exercises are a highly effective way to learn how to engage, strengthen, and use the core and to control pelvic alignment, which is so crucial for ballet and dance in general. Also, performing these exercises while lying on the floor removes the extra forces and work involved due to gravity and the muscle engagement needed to remain upright so that it is easier to concentrate on correct muscle patterning.
With Pilates and other core work, it is important to understand that these exercises are all about the little muscles and very fine degrees of activation and control. It is easy to let the larger muscles take over or to mimic the movements using the wrong muscles. Small and controlled movements of this type are actually harder (at first) but the payoff is worth the effort. A strong core will help you find your "liftoff" and balance and be able to hold that quiet midsection during your barre and centre work. Additionally, strengthening your core will aid your posture, stamina, and overall strength for everyday activities and daily life.
If core work is part of your 2013 resolutions or just something you know you should pay more attention to in your dancing, I hope these resources will help you get started. Happy new year and happy dancing! :)