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,


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.

5 O’clock Shadow: Easy Run = Good mood, refreshing, effortless, creativity

As I ran this morning thinking about the “purpose” of my run, I realized how powerful this run could be for my recovery, for encouraging creativity, and for nourishing my nervous system (my brain particularly) with oxygen and glucose.  From an energy standpoint, the brain uses more energy than any other organ.  “Why strain this morning?” I asked myself.

In the book Thinking, Fast and Slow Daniel Kahneman discusses the differences between two systems of our brain (System 1 and System 2).  For simplicity, System 1 is our ‘intuitive, relaxed, brain’ (your stoner buddy) and System 2 is our ‘analytic, stressed brain’ (your paranoid pal).  Kahneman describes how cognitive ease and cognitive strain tap into more of one brain system than the other.  Cognitive ease = ‘intuitive and creative.’  Cognitive Strain = ‘analytic and suspicious.’  He writes, “When you feel strained, you are more likely to be vigilant and suspicious, invest more effort in what you are doing, feel less comfortable, and make fewer errors, but you also are less intuitive and less creative than usual.”

Check out this graphic from his book to better understand.

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Figure 5: Causes and Consequences of Cognitive Ease

“Easy is a sign that things are going well– no threats, no major news, no need to redirect attention or mobilize effort.  Strained indicates that a problem exists, which will require mobilization of System 2,” he writes.

How does this relate to running?  Now, when I think of the purpose of my “recovery run,” I am thinking of rejuvenation, connecting to my creative self, letting my thoughts drift, connecting dots of ideas freely, and feeling relaxed.  I’m tapping into System 1 before my System 2 dominates the day in the clinic.

How to improve cognitive ease while running: Run a familiar route and distance with or without casual social interaction at a familiar and comfortable pace.  Don’t check your splits or your heart rate.  Just let it be.

FYI, by making Figure 5 blurry, I increased your System 2 contribution to reading ;).


Check out Thinking, Fast and Slow.

Weekly Workout: The “Form Fartlek”

Pronounced just as it is spelled, the term fartlek is Swedish for ‘speed play.’ Running athletes have used fartlek training sessions as a way to perform an unstructured and free-spirited workout blending bouts of faster running separated by recovery bouts. Often thought of in terms of physiological benefits of training, another purpose for the fartlek can be to improve running form (a.k.a. biomechanical factors). I use the term ‘Form Fartlek’ with clients/athletes to focus attention on improving biomechanical flaws while also getting the benefit of improving running economy.

Form fartlek workouts can be utilized by anyone at any level of running. Even elite athletes dedicate substantial time to improving/maintaining running form, especially under conditions of fatigue. The form fartlek is the workout to improve biomechanics. The paramount feature that separates it from other workouts is brief phases of intense focus on body awareness without experiencing form fatigue. It is a steppingstone to more intense training sessions that challenge biomechanics with accumulating fatigue.

The form fartlek can be structured however to adapt to any fitness level. For the average runner who participates in 5k’s through half-marathons, I like to use a somewhat structured approach (less like a true fartlek) by using a 1-minute stride phase at 10k-1/2 marathon pace/effort and 1-minute rest phase running at a recovery run pace/effort with the same cadence (steps/minute) in both phases. Keeping stride phases short allows for bursts of intense mental focus and body awareness. The rest phase needs to be long enough to allow full recovery for the form fartlek. For less fit individuals, doubling the recovery time or decreasing the stride phase time below 40 seconds may be necessary. Accumulating too much fatigue will force form failure, which is not the goal of this workout. If form failure occurs, the workout is terminated and the intensity was overdone.

When beginning form fartleking, pick one biomechanical feature to work on at a time. For example, if the goal is to improve trunk lean, focus on that only. If the goal is to improve cadence, focus on cadence only. As your performance and body awareness related to these improve, layers of complexity can be layered on. Finding the cue to do that may be different for each individual.

Knowing what aspects of one’s form to focus on is challenging making the process of finding the proper cues for each individual to gain body awareness essential. To gather a realistic impression of an individual’s biomechanical strengths and weaknesses, I use a combination of gait analysis on a treadmill using three planes of video (normal and slow motion), running outdoors with individuals to observe changes with speed, fatigue, and on inclines/declines, and utilize a series of movement tests to give me more information regarding strength, coordination, and mobility. Below is a list of generic running form cues / suggestions to consider. As with all things generic, what you’re starting from is relative, so not all suggestions are ideal or correct for each individual.

  • “fall forward from ankles” (effective acceleration phase)
  • “Elevate sternum. Chin down. Eyes up.” (spine alignment)
  • “Shoulders relaxed, down, and elbows in” (relaxed arm swing transferring rotational moment)
  • “Drive elbows back” (arm swing)
  • “Swing fingertips past hips” (arm carriage)
  • “Run from the hips” (core awareness)
  • “Lift from your knees” (hip flexion)
  • “Heels to butt” (increase swing speed by reducing lever arm)
  • “Toes to nose” (ankle dorsiflexion)
  • “Fairy-feet” (light, quick steps)

The reality is that concentration on your biomechanics should always be a part of effective training. Running a faster race is dependent upon one’s ability to maintain energy efficient biomechanics under conditions of fatigue. The good thing is that, it’s just like riding a bike! Coordination improves with practice. You only really lose it if you lose the ability to generate sufficient force.

Tune-Up Running Form to Reduce Knee Pain

If you enjoy running, but nagging knee pain prevents you from getting your weekly mileage fix, try recalibrating your trunk flexion angle. What is trunk flexion angle you ask? Your trunk flexion angle is the bend at your hips or how far your pelvis and torso are from vertical. A recent study by Teng and Powers (2014) found that increasing the average subject’s trunk flexion angle by 6.8o while running at a controlled speed results in a 6.0% decrease in patellofemoral joint (PFJ) force and reduces torque produced by the quadriceps. On the opposite end of the spectrum, running more upright than one’s self-selected trunk flexion angle [closer to a vertical trunk posture] increases PFJ forces 7.4%.   If sagittal plane [side view] mechanics are one of your most salient flaws, this may be a slam dunk for eliminating knee pain.Trunk lean


What does the evidence really mean? The underlying premise is that increased peak forces at the PFJ contribute to mechanical trigger for knee pain. Despite a lack of longitudinal studies to prove this strategy reduces knee pain, one could make the argument that a small reduction in PFJ forces with each step over the entire course of a run is significant. Anecdotally, I have seen this work.

Applying this concept to your running can be difficult without visual feedback.  You can get a close estimate of your trunk flexion angle using a mobile motion capture app such as Ubersense that allows you to draw angles on video captured on your smartphone or tablet. Keep in mind that your speed may affect trunk flexion angle. In the current study, subjects ran at 3.4m/s [7:53min/mile].   Trunk flexion angles between 10o and 18o were associated with reduced PFJ peak forces whereas angles of 1-7o were associated with higher peak PFJ forces.

My advice is to learn trunk flexion angle on a moderately steep hill [~10% grade]. Lean forward slightly from your ankles first, then your hips, and you just might find your gluteal muscles. In my experience, teaching people to run uphill and downhill more efficiently with effective trunk lean and cadence for each task can decrease mechanical stress at the PFJ and in turn, reduce the trigger for mechanical knee pain. Happy running!


Teng HL, Powers CM. Sagittal plane trunk posture influences patellofemoral joint stress during running. JOSPT. 2014; 44: 785-792.

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?


  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



Opinion on Vibram Five Fingers Lawsuit

If you have not heard yet, Vibram USA Inc. has settled a class action lawsuit to pay back consumers who bought their FiveFingers footwear after March 2009 for claiming false health benefits.  The premise for the suit is that the shoemaker claimed wearing the shoes could strengthen foot muscles and serve as an injury prevention strategy.  Vibram USA did not have scientific evidence to directly support their claims.  The $3.75 million set aside for consumers to claim as a refund will be available in the near future.

Marketing is what companies do to attract consumers to buy a product, so would I expect anything less from Vibram? No. Is the $3.75million a big deal to them? I don’t know, but it was probably worth the cost of making the deceptive claims.

My question: At what point do consumers start to understand the quick fix for injury is a myth? If you honestly believed a wholesale change to running “barefoot” would prevent injury, I’m sorry…Go get your money.

The truth is, the marketing claims were not necessarily 100% wrong, but neither were they totally accurate.  Deceiving? Sure.  Vibram’s issue is making claims based upon anecdotal evidence and applying it a large group of people.  Wake up! They are not the only company or individual’s doing this.

I personally used FiveFingers during the winter of 2008 to run “barefoot” on frosted field turf as I recovered from an Achilles injury.  Did it help me?  Probably, but not in isolation. I consulted with a physical therapist and coach, chose proper nutrition, cross trained, progressively returned to running, and worked on my running technique and proprioception.  Did I buy another pair?  Yes, FiveFingers were really comfortable to wear on field turf when it was cold out.

Would I recommend FiveFingers to a client?  It depends.

Footwear is not a magic bullet.  Strengthening, injury prevention, and rehabilitation is rarely attributed to a product, new exercise, or stretching technique.  It is multifactorial, and it is depends on the individual.

Don’t be duped next time.


No, I will not be asking for a refund.