It is all too common that I see patients that confirm, insist and argue that they do ‘abdominal exercises’ daily, and yet complain that they have weak, or poor abdominal strength, endurance and coordination.
There are many ways to strengthen the abdominals that are taught in fitness classes and PT centers internationally and while many are appropriate, an equal amount are not only inappropriate, but dangerous too. The plank, for example, is often touted as the end-all-be-all abdominal exercise, is often the culprit behind many of my patient’s lower back pain. Often seen as a goal to hold for “X” minutes, the plank more often than not is misunderstood, and poorly executed.
A proper plank is when the individual assumes the prone position (belly down), while propping up on their elbows and toes. The abdominals are to be made firm so that the spine is neutral as the pelvis is held up (figure A). Very frequently I observe an increased sway in the lumbar spine (lower back). This leads to increased compression of the posterior elements (joints to the spine), lumbosacral junction (where the lumbar spine and sacrum meet) and the sacroiliac joint. The result is increased pain.
If one were to do a proper plank, the spine is to be held neutral for the duration of the exercise (figure A). Now, holding the body in such a rigid position is all well-and-good if you only live in one position. For those of us that move from position to position throughout the day, having that ability to hold a single position has limited value to our overall wellness. This is the overall concept of dynamic rigidity.
All too often when evaluating a patient performing what they perceive to be a proper plank, I find that they assume a sway in their spine (figure B & C).This can be quite detrimental to their spine due to the posterior compression and loading of the spinal joints, and it effectively shuts off the abdominals, and facilitates the hip flexors (iliopsoas) which will further enhance the posterior compression, and enhancement of an individuals’ pain.
An individual must be able to move freely, and safely. In order to do so, the individual must be able to stabilize their spine in a variety of positions and stresses; optimal and suboptimal. If one were to use the plank as a form of exercise, we encourage the side plank (Figure D). So long as there is no pain in the shoulders, the side plank is much safer for the spine. If assuming the side plank with full leg extension is too stressful, then you can bend the knees to mitigate the stresses on the shoulders, hips and abdominals. The standard side plank has the patient prop themselves up on the elbow, ensuring that the elbow is directly below the shoulder, and while maintaining straight legs, raise the hips. Drawing the umbilicus away from the pant assists in activating the transverse abdominals. Holding this position for a set count, say three seconds, and then lowering ½ way and repeating is a wonderful way to promote dynamic rigidity.
The side plank can be progressed to include a rotation (E), and a leg lift, which is quite difficult (F). As with the standard plank, maintaining a neutral spine is imperative, and there should never be any pain in the shoulders, spine, or hips. When done properly, and without pain, the side plank series of exercises noted here will provide the functional stability required for a healthy spine, actually enhance your athletic performance, and further enhance the cosmetic appeal of a trim, toned abdomen.