Who’s in charge of moving the pelvis? Who calls the shots concerning pelvic stability? Who’s the boss when it comes to balancing the pelvis, both front/back and left/right? Where do we point the finger of blame if the pelvis is moving too much or is not moving enough? Who wears the pants, so to speak? For purposes of this discussion, pelvic stability relates to anterior and posterior tilt, to rotational and obliquity movement, stability and balance. In this light, what kind of exercises do we want to teach to control these aspects of pelvic movement or positions?
The answer to this question depends on what the pelvis moves or is stabilized relative to. If you believe that the pelvis moves mostly at the waist, that the pelvis moves relative to the trunk, then the abdominals, quadratus lumborum and back extensors are your crew and static integration is your game plan. If you think that the pelvis moves primarily relative to the thigh bones, then it’s time for a shift change and a blueprint swap.
The somewhat ambivalent answer is that either sets of muscles, waist or hips, can and do control the pelvis. Either set of muscles can move, stabilize, constrain and balance the pelvis—in certain circumstances. The question is not a one or the other binary question, but a question of when we should train our folks to do it one way and when we should be training the other way.
To answer this question, we need to ask about and observe for when, during daily or functional activity, does each strategy come into play. Let’s start with a partial list of examples of when the waist muscles might control the pelvis—what we might call top-down control:
- Whenever there is no body contact with the ground—sky diving, zero-gravity, trampoline or gymnastics aerials, dolphin kick in swimming, springboard diving.
- When the pelvis and/or trunk is on an unstable surface with legs and arms off the ground—sitting or kneeling on a Swiss ball or lying on a foam roll without limb contact and doing astounding feats of balance.
- Whenever the arms are contacting the ground and the legs are not—handstands, pommel horse, gymnastic rings or bars, Roman chair.
- Whenever the arms are contacting water through the intermediary of a paddle—canoeing, kayaking, paddle boards. The water is the ground, the arms interact with the ground, the waist controls the pelvis, the hip muscles transmute pelvic control into boat control.
- Whenever the chest or upper body is on the ground and the legs are not—some wrestling or grappling moves, the horizontal mambo, lots of Pilates and core stabilization exercises. This is why so many core exercises are done lying down.
- We could be missing some categories, and there are certainly many more examples we could come up with that would fill out the lists, but in essence, that’s it. Not exactly a who’s who of common daily activities.
Why does it matter? Why not just strengthen all the muscles around the pelvis and call it good? Because the twin training strategies of specificity principle and transfer principle says that our training activity should mimic our targeted movement pattern. In this case, this means that whenever we train an activity or postural modification, we need to analyze this aspect of pelvic control as it occurs in our target activity or posture. We then should be training pelvic control in that way throughout the whole range of exercise progressions. Start them early and they ripen to maturity through a steady diet of consistent messaging.
If the hip extensors will ultimately be controlling anterior tilt in standing, they should be trained to create posterior tilt in supine, side lying, hands and knees and chair sitting as well. If the hip flexors will ultimately be controlling posterior tilt in sitting, they should be trained to create anterior pelvic tilt throughout all of the varying positions you train your patient in. And if the hip rotators and adductors will drive pelvic rotation in standing, we don’t prescribe supine knee tilts and control the pelvis with the abdominals.
The Right Tool for the Job
Again, this is not an either/or. Simply identify where you are going and train pelvic control in early or beginning exercise in the same way you want the pelvis to be controlled in the finished product. Five categories were listed above where the pelvis is or has to be controlled by the muscles of the waist. Let’s look for examples of when the hip muscles might have an opportunity to control the pelvis—what we might call ground-up or bottom-up control:
- Everything else.
Moving the pelvis while walking, bending, turning, kicking, getting up and down from the floor, getting in and out of bed and running. Balancing the pelvis in sitting and standing. Stabilizing the pelvis when pushing, pulling, lifting, carrying heavy objects or riding in a car.
When the foot, knee or thigh is in contact with the ground and the chest and arms are not, there is no choice but to use the legs. Think this through! When the chest/thorax, which is the anchor for the abdominals when moving/controlling the pelvis in static integration exercise, does not either contact the floor directly or contact it indirectly through the arms, the pelvis cannot be controlled primarily by the waist. The ground is the mother of all movements, and to take on the job of controlling the pelvis, you will need to be in contact with it.
The Gut Check
So besides acknowledging that for the vast majority of time and for the vast majority of people the legs are in control of the pelvis, we could ask ourselves a related question. What might be some of the drawbacks of over-training the abdominal muscles or asking our patients to constantly tighten their core? While the transfer principle and pattern specificity suggests we do train the abs to control the pelvis in astronauts, sky divers, swimmers, gymnasts, wrestlers and others, we might inquire as to whether we really need to lavish such loving attention on them.
Realize we are talking about using the waist muscles to control the pelvis here. This is not to suggest we excise them from the body as some muscular equivalent of the appendix. The stomach muscles have an honorable and utilitarian role in movement, it’s just not usually the right tool for the job when it comes to pelvic organization or control. We need also be clear that what we sometimes define as the core muscles, the transverse abdominus (TrA) and multifidi, do not control the pelvis in any meaningful way.
They are primarily intersegmental stabilizers, in that they control the relationship between vertebrae. They don’t have a major role in moving or preventing movement of the pelvis into anterior or posterior tilt. They don’t move or prevent movement of the pelvis into rotation or lateral tilt. This has been a source of confusion and misunderstanding within our ranks for many years. We call an exercise core stabilization and think we are training these itty-bitty muscles to rein in the gargantuan pelvis, when what we are really doing with these types of exercises is training the obliques and the rectus abdominus to stabilize the pelvis.
Why not tell our folks to contract their abs to create posterior tilt—either supine or standing?
- The abs pull the thorax down and forward. These muscles, like nearly all muscles, are two-way streets. They not only pull the pubic bone upward, but also pull the sternum and chest downward.
- The thorax is pulled into flexion or kyphosis, with attendant unintended consequences, or the back extensors have to provide a counterweight and we set up a co-contraction.
- The abdominals are closely wired to the anterior intercostals and pectoral muscles, so the shoulder girdles are often pulled down to their doom as well.
- The chest and ribs need to stiffen to provide a stable base, thus rigidifying the thorax and potentially contributing to cervical and shoulder girdle problems.
- Diaphragmatic breathing is inhibited. This can lead to upper chest breathing with associated neck and shoulder girdle issues or respiratory complications.
- Abdominal contractions are part of the somatic reaction to fear or anxiety. Do we really want to throw gasoline on the fire in our patients who already exhibit evidence of high sympathetic tone and muscle hypertonicity?
The Career Change
So if the abdominals aren’t supposed to control the pelvis, what is their role? The job of the abdominal and waist muscles becomes one of controlling the relationship of the pelvis to the thorax or chest:
- Controlling balance reactions—abs work to flex the trunk when ‘falling’ back and the back works to extend the trunk when ‘falling’ forward. They are reactive or secondary to pelvic position/movement.
- Falling along diagonals facilitate these muscle groups asymmetrically or along diagonals— and they can be used to help balance the left and right abdominal antagonists.
- Controlling rotation between pelvis and chest—pushing/pulling laterally or with one arm, ballistic rotational movements.
- Stiffening the trunk to assist stabilization with lifting/holding/carrying weight or to absorb a lateralized shock—keeping chest neutral or aligned with pelvis to keep low back neutral.
We then have three layers or three aspects of lumbar stabilization:
- The hip muscles to control the relationship between thigh and pelvis—pelvic stability.
- The stomach/waist/back muscles to control the relationship between pelvis and chest—trunk stability.
- The TrA and multifidi (along with diaphragm and pelvic floor) to control relationships between vertebrae—intersegmental stability.
To have intersegmental stability, you need to have trunk and pelvic stability. To have trunk stability, you need to have pelvic stability. And, to dig the rabbit hole a whole new wing, to have pelvic stability in standing or sitting, you also need knee, ankle and foot stability. This is an entire stabilization system and no one muscle or group of muscles can claim precedence or exclusivity. This is an integrated system where everyone has a role to play, where everyone contributes according to his particular abilities and relative strength.
This being the case, does it make sense to continue to teach people to do a supine posterior pelvic tilt from their stomach, knowing where this eventually leads functionally? Is this the right tool for the job? Are we to continue to teach control of pelvic rotation from the obliques? Will we continue to assign deep and superficial abdominal muscles the role of kingpin in this integrated stability system, or can we now delegate them to a more appropriate role as respected members of the supporting cast?