Core training for runners: Focus on axial positional neutrality first.

Core training is a term often referring to abdominal exercises that are generally good for everybody including runners to perform for injury prevention and performance. The understanding of the public is shifting beyond just abdominal exercises, thankfully. The goal for this post is to broaden the frame on what core training is and its purpose.

(Axial) Spine, thorax (rib cage) with shoulder girdle, hip girdle

Let’s talk about muscles. So, what are your core muscles? Keep it simple. Just think of the muscles connecting your head to the neck, elbows and knees to your trunk, and all that are in between. In my view, essentially any muscles attaching to your axial skeleton, shoulder girdle, and hip girdle make up your core muscles.

Many professionals specializing in movement performance prefer to use the term “core control” versus “core training” as control implies actively aligning (positioning, orienting, or posturing) the axial system for movement. This could be from any position such as sitting, standing, lying down, et cetera. However, control does not necessarily imply improving the ability to generate force. So “core strengthening” may be used to describe making muscles stronger and/or fatigue resistant. Let’s consider core training as a blend of core control (timing and orientation) and core strength (the ability to produce force). For physics nerds, it may be better understood as kinematics and kinetics.

To enhance one’s understanding of core training, the concept of positional neutrality must be understood. Let’s define positional neutrality as the orientation of the axial skeleton, including pelvis and shoulder girdle, for maximum movement variability of the rib cage, spine, pelvis, arms, and legs relative to the individual. It’s the balance of muscle tension that establishes your starting alignment. In theory, the inability to position the axial skeleton in “neutral” results in either symmetrical and equal suboptimal 3-dimensional range of motion and/or asymmetric equal-and-opposite joint range of motion right versus left and/or skewed rotation observable in the trunk, shoulder, and hip joints unless there is compensation in the movement system. (I know. That’s confusing.) If only the body were this simple, though. One must also consider that there is a degree of asymmetry in the human body that is normal. Traumatic injuries, the parent’s you chose, Wolff’s law / physical stress theory, will also impact an individual’s positional neutrality. The fact is, determining positional neutrality is really difficult for a person to determine without assistance from someone else who knows what he/she is doing.
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Here is a contrived example of why establishing positional neutrality of the axial system is important: I want to run up a steep hill fast. When I push off my left leg, I need my right hip socket to be oriented in a way for me lift or pull my right knee high while still allowing my left leg to push me up the hill. If the start position of my pelvis is skewed in one direction and I go up the hill, the movement will be suboptimal on both sides for different reasons. I would be too good on one side, and not good enough on the other.  If you know Goldilocks, she likes the one in the middle that’s “juuuuusssst right.” Which is to say, if my pelvis is more optimally oriented from the start (positional neutrality) I may be just as good at pushing and pulling on my right leg and my left leg. In theory, this implies improved load distribution on muscles-tendon and joints. I like the sound of that from the perspective of joint health, muscle and tendon recovery time, longevity, and performance.

One of the blessings and curses of being human is an incredible ability to compensate or workaround non-optimal conditions, which is the argument against the need for establishing positional neutrality. But things start to get out of whack when loss of positional neutrality reaches a “not-so-well-defined” threshold that begins to push the available range of motion of joints in one direction. Let’s use another example.

Imagine your shoulder joint as a golf ball (humerus) on a perfectly vertical golf tee (scapula). Gravity is pulling the ball down onto the tee and air pressure is holding it evenly in place on all sides. There is no shear force on the figurative joint and it is happy. Now imagine a strong wind (hypertonic infraspinatus muscle) starts to push the golf ball forward onto the lip of the tee (labrum). The golf ball is no longer aligned in a comfortable resting position through the vertical axis of golf tee unless an equal and opposite force pushes it back onto the tee. Ease the pressure on the figurative labrum, and push the ball back on the tee with your index finger and thumb (subscapularis and supraspinatus). Now tip the golf tee sideways (alter the position of the shoulder socket resting position) so the ball almost falls off. Something has to hold it there, constantly, or it’s going to fall! Again, now there is constant shear stress on figurative joint and lengthening pressure on the labrum and tissues that lengthen over time with sustained stretch.  Is this a good start position?

This scenario in the human body has been described by Shirley Sahrmann as the loss of the PICR (path of instantant center of rotation) of a joint. Ligaments, cartilage, labral tissues, and muscles/tendons begin to adapt as an individual moves further from this ideal position of relative neutrality. The nervous system reorganizes into a new understanding of the body’s neutrality, which may not really be a healthy neutral like the golf tee not aligned with gravity. When ligaments, tendons, and muscle adapt to accommodate new joint position at the shoulder or hip, for example, a degree of instability or impingement toward one direction arises. You may or may not experience pain, but it depends on how much force through a specific range of motion you try to move through and how many times you do it. It just depends on how much it takes to sensitize the tissues.   I can’t tell you how much it will take, but your brain will. “Ouch!”

So what is the biomechanical goal of core training? From an injury prevention perspective, one might say that it is exercise designed for the purpose of restoring or maintaining positional neutrality of axial skeleton. That is to say, it is exercise designed to avoid the positions of instability or impingement defined as moving the extensibility of mostly passive structures (i.e. ligaments, cartilage, labrum) away from the neutral zone of a joint. Some very flexible individuals may have large ranges of motion in all directions (large neutral zone) requiring more control, while others may be very stiff in all directions (small neutral zone). Think of stretchy yoga girl versus 70 year-old stiff guy. So, static stretching may be a form of core training for very stiff individuals if the goal is to improve range of motion. However, pushing into instability where it is not needed through repetitive asymmetrical loading is UNWISE CORE TRAINING!

From a performance optimization perspective, there are two primary goals of core training for runners. 1.) optimizing muscle tension for fatigue-resistant powerful linear motion and 2.) maximizing gas exchange. In other words, core training should complement translation of forces from pushing on the ground into forward linear movement and pumping air into and out of the lungs by twisting the body back and forth repeatedly (A.K.A. running). Right and left alternating

IMG_3664exercise incorporating focused breathing, challenging the thighs-hips, upper arms-shoulders, and thorax is advanced exercise that an be modified in terms of degree of control, speed of movement, and resistance. Body weight exercises on all fours, planking exercises while holding static positions train core muscles. Supported postures on the floor either facedown or on one’s back may be the easiest to feel if the goal is to maintain a static core position. Establishing positional neutrality is where one should start. I believe this requires physical assessment by a professional to specifically determine areas of focus. But, an individual will learn to feel this position and may be able to achieve it while running without exercise before running. With only anecdotal evidence to support the statement, this is what FLOW feels like.

So what is core training? It is performing a movement that challenges the axial skeleton to maintain optimal position for movement of the extremities relevant to the desired task to be performed. It is a blend of control and strength. It is restoring or maintaining positional neutrality first of the axial aspect of the movement system. Its purpose is to maintain the PICR of joints of axial skeleton, shoulder, and hip joints. The abdominals are a big part of the equation, but so are many other muscles. For runners, I will generalize and say that the oblique abdominals, transversus abdominis, breathing diaphragm(s), pelvic diaphragm(s), Latissismus dorsi, multifidi, iliocostalis lumborum, serratus anterior, gluteus maximus, iliacus, gluteus medius, adductors, hamstrings, quadriceps, triceps brachii, et cetera, etc. etc. … are really important. My point is, all muscles are important and play a role in core training.  Ask yourself: What is going to get you to position yourself for the most movement variability from the start position?

In my opinion, exercise fads and programs today revolve too much around ‘mobility’ through aggressive stretching AND strengthening into extension and external rotation (opening up in front) because you don’t spend enough time there all day (sarcasm). For example, imagine sitting or standing all day with what your mother told you was “good posture” (in extension of your spine, perched on the edge of your seat), then going to the gym and doing more extension exercises like back squats, lunges, good mornings or straight leg deadlifts, pull-ups, bench press, Lat pulldown, snatch squats, stretching your hip flexors, gluteals, and avoiding a real curl up where your spine flexes because “it’s bad for your back.” Where is the logic? I am not saying any of those exercises are bad. They have a purpose, but you must look holistically at movement. If you want to make orange juice and all you have are lemons, good luck.

The key takeaways of core training:

  • Core muscles are those that are attached up from the elbows and knees to the axial skeleton, shoulder girdle and hip girdle. Don’t forget the diaphragm right in the middle of it all. Yes, breathing matters!
  • Core training begins with establishing a healthy start position first – Are you oriented appropriately for optimal movement of your arms and legs. Can you achieve positional neutrality?
  • Positional neutrality is the orientation of the axial skeleton, including pelvis and shoulder girdle, for maximum movement variability of the rib cage, spine, pelvis arms, and legs relative to the individual. It is the static observation of a dynamic system.
  • Core training is a blend of timing and body positioning (coordination) and force production.
  • Stretching can be considered core training if it safely enhances the ability to orient / position the body.
  • Learn exercises from an expert that optimize your start position for maximized movement variability without stretching or strengthening into instability or impingement.
  • Add challenge and variability to maintaining neutrality through the axial system during movement. The more specific to the intended task, the better the performance of that task will be. Don’t just do more extension based exercises or planking.

Where resistance training, task specific training, and core training begin and end is a gray area. Be fit, be strong, be coordinated, and keep moving!

 Head for the hills,

-Erik

Post script –

I am a firm believer that being thoroughly assessed by a physical therapist is the best first step to getting serious about exercise, which is why it is mentioned in the post. Assessment should involve a thorough, in-person, one-on-one evaluation ending with relevant patient education. How you move and understanding why you are doing an exercise or modifying a movement habit is important. That said, the goal is not to create fear of moving. The purpose is to empower all humans to move with the precision that maximizes the benefit of exercise and minimizes risk of acute injury or gradual onset of injury. It is far better to keep moving than the alternative.

The Truth About IT band Syndrome

IT band

It’s NOT a FRICTION SYNDROME

The purpose of this article is to inform readers that commonly held beliefs regarding ITBS (iliotibial band syndrome) lack evidence and miss the target on treatment. As dedicated exercisers and competitors doing your part to maintain your health, longevity, and push the limits of human performance, you deserve better knowledge and empowerment to keep going. Gaining control over your pain starts with understanding why.

Point 1. Make sure your pain is not caused by something else. Anybody can point to a body part that is painful and give it a name (i.e. runner’s knee and ITBS). The cause of your symptoms is what is valuable to know, and in order understand the cause, the entire movement system (the human body) should be assessed. Lateral thigh and knee pain has potential pain referral from other structures such as the back or hip, not to mention the myriad movement impairments that can occur from the great toe through the spine. Listing differential diagnoses and explaining the relevance of impairments exceeds the scope of this article, but beware, IT band syndrome can be a wolf in sheep clothing. Seeing your physical therapist is an inexpensive first step to establish the factors giving rise to your pain, and ruling out other sources of pain referral.

Point 2. Despite the ‘word on the street,’ IT band syndrome is NOT a friction syndrome or a bursitis. Anatomic research shows there is not even a bursa there!1,2 And, despite the common belief that the IT band tendon slides and rubs back and forth over a bone in the knee, the functional anatomy debunks this phenomenon. Anatomical research has revealed that two slips of tendon with different bony attachments are tensioned at different ranges of knee motion giving the appearance of a band of tissue sliding back and forth. 2  What can occur is compression of a highly vascularized fat pad in that outside part of the knee, which may or may not be the anatomical source of pain.1,2

Well, what about stretching? IT band syndrome is caused by a tight IT band, right?

Point 3. It’s highly unlikely your IT band is too short. Research shows that clinically identified “tight IT bands” are not predictive of IT band pain anyway.3 What’s more, the typical static stretching does not actually lengthen the iliotibial fascia, so why is everybody stretching so much? Let’s review functional anatomy again. Under your skin, your thigh muscles are circumferentially wrapped in a Saran wrap-like tissue called fascia. That fascia is connected all the way down to the back of your thigh bone, running nearly the entire length of the thigh bone. The IT band is simply a thickening of that tissue, and it is not moving anywhere. Consider that a maximal muscle contraction of the TFL causes a 0.2% change in IT band length.1 Furthermore, research shows you are much more likely to be relaxing and lengthening the supportive hip muscles…you know, the muscles you are supposed to be strengthening (see point 4).   Therefore, stretching can actually be counter-productive despite how good it feels while doing it.

Point 4. Strengthening hip girdle muscles has scientific support.4,5 But there is a caveat. It is really easy to strengthen muscles that are already strong, and it is really difficult to strengthen muscles that are relatively weak. It is import to first reeducate your nervous system to recruit specific muscles before strengthening. My mentor always says, “Just because you wear your muscles, does not mean you use them.” So as long as you are recruiting specifically weak muscles, have at it, Jane Fonda. Though not a cure-all, strength and endurance of the hip and pelvic girdle contributes to improved alignment of the lower limb joints while running. What is often the missing component, however, is functional coordination of these muscles while running.

Point 5. Sorry, there is no secret formula for treating IT band syndrome. Passive modalities such as ice, heat, or massage may confuse your nervous system long enough to experience short-lived relief, but the pain will return unless you take a holistic approach to correcting movement patterns. About the foam roller, my professional opinion is that it can help mobilize adhered tissue layers and relieve painful myofascial trigger points (small painful bundles of muscle and connective tissue). However, if the impaired movement is not remedied, those bundles of joy will return.

Point 6. Please, do not give up without a fight. If foam rolling, stretching, icing and general strengthening have been unsuccessful, you now have a better understanding why. So the next time someone proclaimes, “Oh, you just have a tight IT band!” you know better.

My challenge to those who accept that pain is part of who you are as a runner, make time for yourself to learn about how you move. Subtle tweaks can make big changes. Movement is vital to your health, and the precision of your movement is vital to the health of your movement system. Remember, you only have one.

Citations

  1. Falvey EC, Clark, RA, Franklyn-Miller A, Bryant AL, Briggs C, & McCrory PR. Iliotibial band syndrome: an examination of the evidence behind a number of treatment options. Scand J Med Sci Sports 2010; 20:580-587.
  2. Fairclough J, Hayashi K, Toumi H, Lyons K, Bydder G, Phillips N, Best TM, Benjamin M. Is iliotibial band syndrome really a friction syndrome? J Sci Med Sport 2007; 10: 74–76.
  3. Devan MR, Pescatello LS, Faghir P, Anderson J. A Prospective Study of Overuse Knee Injuries Among Female Athletes with Muscle Imbalances and Structural Abnormalities. Journal of Athletic Training 2004; 39:263-267.
  4. Nohren B, Davis I, Hamill J. Prospective study of the biomechanical factors associated with iliotibial band syndrome. Clin Biomech 2007; 22:951-956.

Article Published in March 2014 issue of Northwest Runner Magazine

Check out Frank Netter’s Atlas of Human Anatomy and related website

Does improving hip extension mobility actually improve running economy?

Back, pelvis, and hip deep anatomy (anterior view). Psoas and iliacus flex and laterally rotate in open chain movements maintaining the precise axis of rotation in the acetabulum. In closed chain (standing), they are anterior struts for keeping the body upright and stabilizing the lumbopelvic hip complex. The iliofemoral ligament “checks” excessive anterior translation of the femur head in the acetabulum when extending and medially rotating the femur.

Runners, coaches, and other athletes are always looking for ways to prevent injury and become more efficient and economical while running.  In this example, let’s consider our athlete is the weekend warrior with a 40 hour/week desk job or high school student-athlete. This person sits several hours a day, with maybe a 10-minute walking break every hour. Conventional wisdom is that this person will develop a lack of hip extension due to tight/stiff hip flexors.  The hypothesis is that stiff hip flexors shortens stride length negatively impacting running economy, defined as steady-state oxygen consumption at a given running speed.

So does improving hip extension range of motion in individuals “lacking hip extension” improve running economy? According to the evidence, the answer is NO! Though a 20 year old article, this topic has been researched.1 Subjects were young, athletic male college students determined to have “less than normal hip extension” meaning they were unable to passively extend the thigh past 0 degrees. Subjects were divided into a THREE DAYS PER WEEK (yes that is all) hip flexor stretching group and a control group. On average, hip extension improved 9.8 degrees in those who stretched 3 days per week. Despite a statistically significant change in passive hip extension measured using the modified Thomas Test, improved running economy did not occur. The control group (those who did not stretch) actually showed greater improvement in running economy.

What does this mean practically? Improving hip extension through stretching anterior hip structures does not improve running performance at speeds associated with running at paces one could maintain for 10-20 minutes. Could it actually be counter-productive? From both injury and performance perspectives, YES!  Consider that running at faster speeds requires sufficient anterior stiffness to withstand the forces generated by some of the strongest torque producers in the body; the gluteals and hamstrings. It has been speculated with good biomechanical evidence that excessive hip extension forces and joint angles are associated with injury to the anterior hip joint.2 Furthermore, improving your stride length is not primarily the result of greater hip joint extension range but rather more distance traveled during the float phase of running. This requires power, the perfect combination of force production and timing. A well-timed and stronger stretch-reflex in the hip flexors generates a more powerful hip flexion moment. Finding the optimal blend of stiffness and mobility at exactly the right time is what is important.  Improving economy comes down to practicing a skill and improving timing of force production along with other metabolic processes.

How does this affect you? First, understand the goal of your flexibility exercises. If you are stretching because of hip pain, back off stretching and get assessed by your physical therapist. Stretching could be counterproductive even if you get short-term relief of pain. Are you certain you have limited hip extension? Don’t assume that working at your desk creates short and stiff hip flexors. Videotape yourself from a side view running at fast and slow speeds when you are not fatigued. Do you lose your “neutral pelvis” position. Even if you notice that your low back is arched and your pelvis is anteriorly tilted, do not assume you have stiff hip flexors. This often is a coordination issue that can be addressed through specific trunk and pelvic girdle movement awareness.

Related Blog Posts:

Are you sure your hip flexors are tight? If so, why and who cares?

Psoas, please release me… Let me go!

Does excessive sitting shorten the hip flexors?

Sources:

  1. Godges JJ, McRae PG, Engelke KA. Effects of exercise on hip range of motion, trunk muscle performance, and gait economy. Phys Ther. 1993; 73:468-477.
  2.  Lewis CL, Sahrmann SA, Moran DW. Effect of hip angle on anterior hip joint force during gait. Gait and Posture. 2010; 32:603-607.

Post Joint Mobilization Recommendations

What is mobility without control?  A recipe for injury and loss of training time.

The purpose of this blog post is to highlight the need for more of us to follow through with the process of restoring function after gaining mobility.   Specifically, I want to highlight that the goal after gaining mobility is to achieve the neuromuscular control and  tissue resilience to handle the load demands placed upon the body in that increased joint range.

Joint mobility can be achieved through stretching, repeated movements, or manual techniques.  Phyical Therapists will use manual (hands on) joint mobilization techniques to improve joint accessory motions and physiological motions so a client can perform a desired task without pain or pathologic movement.  Physiological motions refer to gross movement such as flexion, extension, and rotation movements. An example is bringing the thigh toward the chest to create hip flexion.  Accessory motions refer to how the joint surfaces move against one another.  For example, when the head of the femur is laterally rotated on the acetabulum (hip socket)  in an open kinetic chain (when the leg is not in contact with the ground), an accessory anterior and superior glide of the femur on the acetabulum occurs.  In a healthy movement system, accessory motion should be held in check by passive structures such as ligaments and cartilage (labrums, meniscus, etc.) and controlled by precise coordination of muscles around the joint.  In theory and clinical application, maintaining a precise center of rotation is desirable.  Though not a perfect example, consider a suspension bridge without sufficient control to limit excessive motion. (See Tacoma Narrows Bridge collapse below).

*Skilled assessment should always be performed prior to attempting self administered forceful joint mobilization techniques.  Hypermobility is contraindicated.  Remember that just because a structure feels “tight” does not mean that the structure needs mobilization.  “Tightness” is a sensation! 

I am a prime example for this blog post.  3 years ago, I enjoyed a gnarly grade II inversion ankle sprain overstretching my left lateral ankle ligaments.   Recently I have had midfoot pain with running or hopping on one foot and it was increased on for 24-48 hours after long runs.  A few colleagues assessed my ankle and foot finding key findings limited active/passive dorsiflexion and restricted mid foot pronation (functional and passive) among other impairments.  Following manual joint and soft tissue mobilization techniques, I had no pain with repeated single leg hopping and my percieved ability pronate the foot improved.  With improved pronation, my lower extremity should more effectively absorb impact forces compared to my baseline at initial assessment.  However, my lower extremity needs to do this in a coordinated fashion.

My simple post mobilization regimen has been

1. Activity modification (reduction in volume and intensity of runs for 2 weeks)   2.  Single limb balance on level and uneven surfaces, with single limb squat .  3. Low load eccentric calf strengthening x1 to fatigue 4.  Single leg hopping x1 to fatigue