Off The Road – Core Stability

by Russ Ebbets, DC

continued from home page

It is important right off the bat to clarify the distinction between core strength and core stability. Strength is a speed and power quality. Physiology dictates that speed and power is related to the white muscle fibers we have in our muscles. Sprinters, jumpers and throwers, track and field’s speed and power events, prize a higher content of white fibers.

Core stability on the other hand is an endurance quality. Were one to do a biopsy of the core muscles one would find red muscle fibers. Core strength is actually a misnomer, our core is not for speed and power as much as it is for endurance, posture and stability.

Posture needs to be viewed in both a literal and figurative sense. Core stability helps with your mother’s admonition to “stand up straight” but it also is necessary to position the trunk in such a way that the limbs can be accelerated to produce the running, jumping and throwing actions involved in track and field and most ball sports.

At the corners of the body’s core are four ball and socket joints. Ball and socket joints are multi-axial, meaning they can move in every direction. Most shoulders retain this ability throughout one’s life. The hip is the body’s largest ball and socket joint. Mobility of the hip is significantly less than the shoulder for most people, with the possible exception of hurdlers or ballerinas.

While hip mobility is laudable it can become problematic especially with directed actions. In sprinting the optimal action is straight ahead movement. In fact, any wobbling or side to side type movement at the hip is counterproductive to the sprinter’s overall goal of a faster time. But the ball and socket joint of the hip, if not properly stabilized will wobble and exhibit unwanted movement that can decrease one’s force production and produce slower times.

The shoulder joint presents with a slightly different scenario. The stability of the shoulder comes into play anytime one tries to push, pull or throw with some force. There are four small muscles ranging in size from about the size of one’s thumb to the palm of the hand that initiate shoulder stabilization. Collectively these muscles are called the rotator cuff.

All shoulder problems involve all four of the rotator cuff muscles. No exceptions. And while these are relatively small muscles their injury or dysfunction leads to a domino type dysfunction of the shoulder girdle, across the upper torso to the neck and even problems down the arm to the hand.

The rotator cuff muscles are located on the posterior aspect of the body where they literally remain “out of sight” and out of mind for most people. The muscles are ignored until injured and then they become unforgettable registering pain with virtually every movement of the hand or arm. Rehab of an injured rotator cuff is often slow and frustrating.

While most of one’s walking actions are linear most arm and shoulder actions are what could be called “gathering actions.” White and blue collar workers alike bring their work to their middle or core over and over again. Even the resistance training most athletes go through follows the same pattern. The significance of these gathering actions is that over time they create an imbalance within the rotator cuff. The internal rotation (palm down) rotator cuff muscle, the subscapularis, becomes disproportionally stronger than the two external rotators, the teres minor and infraspinatus.

The next time you are waiting in line take a moment to study the resting position of people’s hands. Are they flush against the side of the leg or is the arm twisted with the palm facing backwards? The backward facing palm is a tell-tale sign of a current or developing shoulder problem.


A simple solution to correct this hand pattern is the side-lying dumbbell fly (Figure 1, Side Lying Dumbbell Flys). This can be done with a can of soup or other weighted object. Start out easy with 10-12 reps and work to 15 before increasing the weight. Perform the grand sweep with the arm first, then place the arm on the flank and perform a smaller sweep.

A second option would be to dribble an 8-10# medicine ball against a solid wall or a tree. A little bit of this goes a long way. Remember what we are seeking here is tone of the rotator cuff muscles, not hypertrophy. To create muscular hypertrophy could cause a pinching or impingement syndrome in the shoulders.

The upper core is less of a running problem. Shoulder injuries to runners are rare unless there has been a fall that one has tried to stop with an outstretched hand. Shoulder injuries for the thrower or vaulter are more common due to the use of the arms in those events and a more aggressive weight training program that those events require.


The lower core is a series of muscles that wrap the abdomen top to bottom and side to side. The traditional sit-up may contribute to a beautiful set of 6-pack abs but usually does little to tone the lower core muscles responsible for stabilizing or initiating trunk rotation. (Figure 2, Core Muscles - notice diagonal patterns)

One can observe weak abdominal muscles in a runner whose trunk makes it look as if they are wiping down a table. Their arms cross the midline and the shoulders twist back and forth. A complaint weak core runners have when they do speed work is that they just “never feel smooth.” What they are noticing is that the shock of ground contact is “jarring” their body. With a weak core there is nothing to attenuate that ground contact force. The solution in part to lower core stability is a series of plank positions.


A plank position is basically a push-up position without the push-up (Figure 3, Plank Position - can be done on elbows). It is an isometric contraction of the abdominal muscles. Isometric contractions are those where there is no movement. Isometric training has gone in and out of favor over the last 30 years. Isometrics are actually a highly effective means to make stronger muscle-tendon-bone, ligamentous and fascial plane connections throughout the body. This is an example of “invisible training” of the body that is not seen and generally ignored.


Side planks are important to insure all around core development (Figure 4). Side stars can be a challenging position that isolates the side of the trunk muscles. A second variation is to lie on one’s side and perform the classic yoga move called Side Raise. One can raise the top side leg or lift both legs together to include some toning of the inner thigh. These side planks isolate the lateral aspect of the core. Start out conservatively holding the position for about 10 seconds. Over a week or two increase to 2-3 sets of 10-15 seconds each.


Isolation and stabilization of the back muscles can be done with a back triangle of “dead bug” exercise (Figure 5, Dead Bug - Back Plank). Keep one foot firmly planted on the ground, raise the opposite leg and maintain a motionless abdomen with the free leg held straight. Once again 10 seconds on each side, alternating sides 2-3 times will tone this area.

Up to this point the traditional sit-up has avoided discussion. While sit-ups were no doubt the staple of most high school gym classes sit-ups have fallen out of favor more recently. There are several reasons for this with the leading one being the stress sit-up impose on the lower back.

Ten sit-ups does not pose a problem. It is the repeated trunk flexion of 100’s and 100’s of sit-ups done over time that places excessive wear and tear on the lumbar spine’s discs. This area is a problem site for long-term runners (read that as 10+ years or a masters runner). Remember 2/3 of one’s bodyweight is above the navel and with each running stride there is a pounding the L5-S1 disc takes as weight is shifted leg to leg. Factor in jumping exercises, high mileage days, an aggressive race schedule, lots of running on concrete surfaces and the occasional stumble and one can begin to see why low back pain is an “occupational hazard” for the serious runner.

Much of the pageantry of thoroughbred racing centers around “the look.” Owners buy horses by how they “look.” The parade to the post allows the common to see up close what their horse looks like. Even the big hats fill in some of the dots of the grand mosaic. But if “the look” was all there was to horse racing every horse would be a champion, every hat worn by a princess and all the railbirds rich. It’s not the case.

Over the last 20 years there have been several fitness programs that have championed the importance of the core. While the nuances of each program might slightly differ in total their intent and means to an end help stabilize the body’s core.

Core stability is like one’s personal values. Values are what one does and how one acts when no one else is watching. With core training the results are not immediately obvious. But it is the long-term benefits that one receives – more productive workouts, a greater work capacity, healthier and more efficient movement patterns that translate to a more productive career.

It is critical that one ask and forthrightly answer the questions – what do I want from all this running? And what am I willing to do to get it? If the core stability concept is new to you, regardless of your level of participation or athletic history, slowly introduce the changes to your routine over the course of one to two weeks. Core training pays big benefits for a small investment of time, usually less than 3-4 minutes of daily practice time. What do you want from all this running? What are you willing to do to get it?

Russ Ebbets, DC is a USATF Level 3 Coach and lectures nationally on sport and health related topics. He serves as editor of Track Coach, the technical journal for USATF. He is author of the novel Supernova on the famed running program at Villanova University and the High Peaks STR8 Maps trail guide to the Adirondack 46 High Peaks. Copies are available from PO Box 229, Union Springs, NY 13160. He can be contacted at

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