Simply defined, core stability is “the ability to create extremity movement without compensatory movement of the spine or pelvis”
and in the broadest sense is “the ability to produce and transmit force from the ground without energy leaks at the hips, spine or scapulo-thoracic joints”. Energy leaks are defined as points at which energy is lost during the transfer of force from the ground.
Energy leaks are a result of the bodies’ inability to stabilize a particular joint. Torso strength encompasses core stability, hip stability and shoulder stability and most importantly the ability to move force from the ground to the extremities while maintaining stability in the aforementioned areas.
Setting the Stage for Stability: Training the Deep Abdominal Muscles
As the study of the interrelationship of low back pain and the training of the abdominal muscles continues it is obvious that the paradigms will continue to shift. One such shift is occurring currently. Previously I have written and spoken extensively about the Australian methods of training the deep abdominal muscles.
The work of Richardson, Hodges, and Jull, through their landmark work Therapeutic Exercise for Spinal Segmental Stabilization in Low Back Pain, has significantly advanced our knowledge of core anatomy and muscle function. In actuality, that book and the research that preceded it have forever changed the way that training is performed. Interestingly enough, some practitioners in the field have rejected the Australian concepts for a broad range of reasons. The most notable and credible among these critics is Canadian Dr. Stuart McGill. McGill provides a sound biomechanical rationale for why “hollowing” as he refers to the “draw-in” maneuver will actually decrease stability. McGill advocates a technique he refers to as “bracing” in place of “hollowing” or “drawing-in”.
Although I understand Dr. McGill’s premise, I still believe that
learning to hollow or draw-in still is a necessary skill for our athletes to achieve.
Terminology
Drawing in – the action of bringing the rectus abdominus toward the spinal column. Ideally this is done by contracting the transverse abdominus and internal oblique muscles
Hollowing- Another description of a drawing-in action that assumes that the action results in a decrease of waist diameter.
Bracing- The technique taught and favored by McGill that involves a simultaneous co-activation of both the transverse abdominus, internal oblique, external oblique and rectus abdominus. In bracing there is no attempt to decrease the diameter at the waist only to activate the muscles.
Although I am clearly not qualified to dispute Dr. McGill’s research, I have a point of theoretical disagreement. McGill’s research clearly shows that drawing-in or hollowing can decrease base of support and stability of the spine. However, we are teaching drawing-in as a neuromuscular awareness exercise, not as the primary vehicle for stability. McGill himself states that “hollowing may act as a motor re-education exercise”. In addition, most of our athletes are the classic “Janda lower crossed body” with an almost protruding abdominal wall and a significant lumbar lordosis. (Vladimir Janda, was one of the pioneers of manual medicine in Europe. He introduced many of the concepts of muscle imbalance on which many of the concepts of core training and functional training are now based.) In these athletes I believe that teaching drawing-in simply brings the rectus into normal alignment from a position of concavity. In reality the athlete is not hollowing but simply bringing the abdominal wall back to its intended position of stability. In other
words, the goal is to simply to bring the abdomen back to its normal anatomical position. The key here is that drawing in for a lordotic athlete would not in fact decrease the base of support as McGill suggests.
In my opinion performing “draw-in” exercises literally sets the table for all other stability exercises. We are teaching athletes to contract a muscle that they may not be capable of contracting voluntarily.
Athletes or clients unable to “draw-in” will not be able to properly stabilize in any other movement pattern. In fact, I don’t believe that an athlete who cannot “draw-in” would be able to “brace” as
effectively. The purpose of the “draw-in” exercises is not really to be exercises in themselves but to allow clients to learn to properly set the core musculature in all activities. Initially the draw-in concept is applied in quadruped or bridging exercises. The draw-in is in my opinion the foundation on which all other stability exercise is built.
Whether you choose to draw-in or brace, the execution of
quadruped or bridging exercises remain the same. The difference is not in how you do the exercises, but in how you choose to set the table. The end result remains the same.
The Science Behind Core Training
Torso strength could be a book in and of itself. The training of the torso, core, or pillar, depending on your descriptive term of choice is filled with controversy and confusion. Advocates of powerlifting or Olympic lifting seem to feel that most of the scientific advances made in the areas of medicine and physical therapy do not apply to strength sports. As with many points made by those who
consistently lift weights with two feet on the ground I respectfully disagree. I think that our influences in the area of injury prevention should be the physical therapists who deal with injured athletes not people from the sports of powerlifting or Olympic lifting.
It is very easy for those who never have to worry about athletes running or jumping to tell us how to train those who do.
Unfortunately when powerlifting or Olympic lifting coaches begin to move from strength and power development into performance enhancement problems arise. I believe that you cannot deny
science. Science tells us that the deep abdominal muscles (internal oblique, transverse abdominus, and multifidus) play a key role in the stability of the lumbar spine. Many in the strength community disagree. I believe that disagreement is healthy, but I have seen far too many strength athletes with problems in the lumbo-pelvic hip complex (hip and low back) to think that exercises like squats provide enough stability training.
Athletes and clients must learn to move from the hips, not from the lumbar spine.
I believe that most athletes with lower back pain or hamstring strains have poor hip and/or lumbo-pelvic mechanics and as a result must extend or flex the lumbar spine to make up for movement unavailable through the hip.
I believe that learning to stabilize either via a bracing maneuver as described by McGill (simultaneous use of the rectus abdominus, and the deep abdominal musculature) or by executing a “drawing-in” maneuver is key to being able to strength train and remain healthy. Many who have read my previous work might consider this a departure from my previous thoughts. In fact it is only the
continuation of my education. Six years ago I did not even
understand the anatomy of the deep abdominal musculature. Now I am well-versed, but continue to study and learn. McGill’s work has continued to advance our knowledge of the workings of the
abdominal musculature, and I must admit that his evidence is compelling. Dr. McGill’s Low Back Disorders is the latest landmark work for any strength and conditioning professional. I think that the disagreements as to how to stabilize between people like McGill and Paul Hodges are primarily disagreements of semantics as they relate to strength training and not really of science. I believe that the Australian research in the area of drawing-in is still applicable to athletes because as I stated previously, most athletic bodies are lordotic.
As I have continued to read the work of physical therapist Shirley Sahrmann, I have also changed my ideas on the ideas of training
“local muscles” versus “global muscles”. Sahrmann makes some interesting comments relative to core training as it relates to the larger muscles, like the external oblique and internal oblique.
Sahrmann has isolated the essence of any exercise but, most importantly core exercise.
Sahrmann states: “Motion is restricted to the segment that is supposed to move”. (2002, p )
Sahrmann, like McGill relies heavily on EMG data to prescribe exercise but, her prescriptions run away from the norm. Sahrmann recommends a “curl up” (figure 4.1 ), as a segmental movement not directed primarily at the rectus but, directed at the internal oblique.
Figure 4.1 Curl Up
In fact Sahrmann states “the primary disadvantage of improving the rectus abdominus is that the rectus cannot produce or prevent rotation, and shortness or stiffness contributes to thoracic
kyphosis”(2002, p 69). However, the data Sahrmann cites shows that the highest internal oblique activity is actually when a curl-up or segmental crunch is progressed into a full sit-up. Sahrmann makes clear distinctions as to how this should be performed and makes a wonderful case for including an “old school” exercise in the torso strength program. Sahrmann also cites the reverse crunch (figure 4.2) as a key external oblique exercise. This is a hips-to-shoulders flexion exercise that elicits high external oblique activity. (2002, p 69)
Glute Activation and Injury Prevention
To really understand core training we need to look at the key compensation patterns that occur when someone attempts to train the core. As I stated previously, substituting lumbar extension for hip extension is the major culprit in many of the problems that we see. This is one of the primary problems in lower back pain and may be one of the key areas we attempt to improve over the next few years. McGill uses the term “gluteal amnesia”. Mike Clark might
Figure 4.2 Stabilized Reverse Crunch- a key exercise
call it a problem of reciprocal inhibition or synergistic dominance.
Both are “Jandaists” if I can be so bold as to make up a word. Both McGill and Clark identify the same problem. The problem is: Are the glutes weak because the psoas is tight or, is the psoas tight because the glutes are weak? It may be a classic interdependent, chicken and egg, scenario. Either way, proper strengthening of the glutes will be the best cure. In fact we may not even be
strengthening but just reeducating the neuromuscular system. In reality most early strength gains are in more neural than contractile.
In order to do this the athlete needs to be able to set the core and fire the glutes. Initially this is best done in quadruped to eliminate hamstring contribution. Sahrmannn presents another series of thoughts in her book. Sahrmann believes that anterior hip pain can be the result of poor glute function and the resultant synergistic dominance of the hamstrings. (2002, p. 15). Sahrmann discusses the simple biomechanical explanation by citing the lower insertion point of the hamstrings on the femur. If the hamstrings are
consistently called upon to be the primary hip extensor, the result will be anterior hip pain in addition to hamstring strains. The anterior hip pain is a result of the poor angle of pull of the hamstrings when used as a hip extensor.
The key to the future of torso or core training will be in combining all of the movements necessary without overemphasizing or
underemphasizing a particular muscle or movement. If I look at my failings over the last five years, I would say that it would be in not training the larger global muscles. So much emphasis was placed on draw-in exercises and on stability that many of athletes could not perform sit-up or curl-up type exercises.
If I can make one clear statement of what I believe now about training, particularly as it applies to the core:
Glute activation or more importantly, lack of glute activation, may be the root of many of our evils.
As we look at more and more athletes, both injured and healthy, the inability to activate the gluteus maximus and gluteus medius stands out as the root cause of at least four major injury syndromes:
1) Low back pain relates strongly to poor glute max activation (Poor glute function will cause excessive lumbar
compensation)
2) Hamstring strains relate strongly to poor glute max activation (Think about synergistic dominance)
3) Anterior hip pain relates strongly to poor glute max activation. (This relates to the poor biomechanics of hamstrings a hip extensors)
4) Anterior knee pain relates strongly to poor glute medius strength or activation.
Sahrmann makes one of her many lucid points “when assessing the factors that contribute to an overuse syndrome, one of the rules is to determine whether one or more of the synergists of the
strained muscle are also weak. When the synergist is weak, the muscle strain is probably the result of excessive demands” (2002, p.37)
I call this looking on the roof. If you see water leaking into your house, you don’t simply try to plug the hole or paint over the water stain. You look for the source of the water. You look on the roof for the problem. The same applies to injuries. Don’t focus on pain site;
focus on the pain source. In our case, the source keeps coming back to the glutes. In the bigger picture, coaches should look at every non-traumatic (non-contact) injury as having a root cause in either poor program design or, weakness of synergists.
We will perform glute
activation at the beginning of every workout to attempt to develop better conscious awareness of the function of the glutes and to hopefully
“wake them up” so that they will be greater contributors to the workout. This whole
“glute activation” thing can become a problem as you will be asking your athletes or clients to continually touch their rear ends. In addition, you will be continually
touching people’s rear ends.
A word to the wise, in our litigious society sexual harassment is a problem, be careful we are treading in dangerous but necessary water.
One small problem. When does glute activation become resistance training versus core training? I must confess to being unsure at this point.
There is a thin line between hip dominant exercise and core training. The solution may be to do your core work (quadruped and bridging) on the days you are doing your
Figure 4.3- X Superband for Glute Medius
hip dominant lower body exercises or perhaps to perform some type of hip dominant exercise every day.
Glute Activation Keys
• Perform glute activation as the first thing in your warm-up
• Straight leg mini-band or Super Band X walks ( Figure 4.3)is great for glute medius ( posterior fibers)
• For glute max use either quadruped hip extension or Cook hip lift
Let me be clear. Perform glute activation prior to every workout.
Core Stability Exercises
Bridging and quadruped exercises are designed to promote glute function and stability. Gray Cook classifies these exercises as “core stability” because there is no movement of the spine. Exercises like crunches and reverse crunches are better classified as “core
strength” because the spine is moving. Cook states the concept simply. In order to be doing core stability exercise there must be no movement of the core. Exercises that incorporate core movement are core strength exercises.
Quadruped Progression
Although I discussed Quadruped exercise in detail in Functional Training for Sports, this information clearly needs to be revisited.
McGill’s research has validated my thoughts relative to quadruped exercise and, it is essential that all athletes work through this progression.
The quadruped exercises are frequently viewed as
rehabilitation exercises and have largely been ignored by strength and conditioning coaches and athletic trainers. I think many coaches view quadruped exercise as simple and a waste of time. The quadruped exercises may not make sense at first glance, but only because these exercises are often performed incorrectly. In many cases the results of these exercises become the opposite of what was intended.
Quadruped exercises should teach athletes how to recruit the glutes while maintaining a stable torso. Instead, athletes often learn that they can mimic hip extension by extending (or hyper-extending) the lumbar spine. The purpose of this quadruped progression is to teach the athlete to stabilize the torso with the deep abdominals and multifidus muscles and to simultaneously use the hip extensors to extend the hip. A great deal of low back pain is related to poor range of motion and function of the hip that must be compensated for by lumbar extension or rotation.
Obviously the multifidus component is not present until the hip or arm is extended. The multifidus is incorporated when the athlete or client has to stabilize against a rotational component produced by a three-point stance. Quadruped actually refers to the starting position. Most of the exercises are actually done from a three-point stance.
Pelvic Floor- the pelvic floor component is another component that was not addressed in Functional Training for Sports. Pelvic floor is a sensitive issue because coaches are dealing with discussions of body areas and body functions with athletes who may not be mature enough to understand the essential nature of engaging the muscles of the pelvic floor. When dealing with adult athletes or clients, core training will be drastically improved by asking the athlete or client to engage the pelvic floor while performing any stabilization exercise in quadruped or in a bridge position. It is simple enough to tell athletes or client’s to mimic the action they would employ if they realized that they had to use a bathroom, but
the line was very long. This usually is enough to get the message across.
Quadruped Draw-In
Level 1 This has become the position of choice for teaching