Approaching joint assessment from the perspective of “cylinders”.

Our approach to every joint assessment has long been to visualize and assess the joint(s) as a cylinder since the body parts are cylindrical in form. This has been our approach, and they way we teach, for many years. At each number on the clock (cylinder) there is a theoretical muscle that provides stability to the joint in that vector during loading. The most accurate assessment would be one that investigates the ability of each muscle around the clock (cylinder) to see if it has sufficient S.E.S. (Skill, Endurance, Strength) as well as how well that muscle(s) participates with the synergists, antagonists and agonists (ie. motor patterns for stability and mobility).  We do this at each joint along the kinetic chain when assessing someone with a clinical or functional problem.  

When dealing with a frontal plane drift, as in the 3rd photo above where you see the person’s (black shorts) pelvis drift laterally outside the perpendicular foot line, one could naturally assume that the gluteus medius is weak (9 o'clock) but the wise clinician would also look at the other side of that cylinder to see if the adductors were involved (3 o'clock) since that is 180 degrees through the joint axis.  (Note: Runners are sagittal athletes so frontal plane weaknesses are often seen. This is not desirable however, this is a perfect example why runners should cross train more into lateral and angular sports to ensure that the sagittal plane does not dominate.) Obviously the foot and the knee also need a similar cylindrical assessment approach. We have spoken loudly many times  here and on our podcasts over the years that quite often there are multiple flaws in a presentation, typically a focal cause and one if not several compensations as a functional adaptation strategy around that central flaw. In this runner’s case there could be medial knee weakness or foot weaknesses that are affording too much medial drift and spin of the limb resulting in the lateral pelvic drift compensation.  But, just because the gluteus medius shows up weak does not mean that it is the focal point of clinical intervention. If one facilitates the gluteus medius and does not address the causative lower cylinder issues then they are quite possibly empowering the compensation and enabling the aberrant activity to continue. Knowingly or unknowingly layering armor or inappropriate strength to a pathologic compensation pattern at a focal joint level that is not the focal cause should be a clinical crime, but it is done every day by people who do not know better even though their efforts are well intended.

Ok, we got on a bit of a soap box rant there, sorry. Back to the case at hand.  

Your assessment should not stop at the frontal plane in this case. If there is an imbalance in the sagittal plane in this sagittal athlete this can be a causative problem as well, which is why the cylinder approach should not stop at the frontal plane or when you find that first major weakness. In frontal pelvic drift cases, there is quite often an anterior pelvic tilt where the lower abdominals can be weak, the low back is slightly extended and the paraspinals are more active. This is the classic “impaired hip extension pattern” and sets up a Janda/Lewitt style “Layered Syndrome”. Most of the time, resolving this sagittal flaw will show immediate improvement of the frontal plane deficits.  But, do not think it is as simple as re-facilitating these 2 patterns. Remember, neuromotor reprogramming and patterning takes 8-12 weeks by some sources. And remember, the initial strength gains in the first few weeks are from neuroadaptation (ie, skill gains in coordination), these gains are not the true physiological endurance and strength gains that we desire for an athlete.  Those gains take time but they are the ones that we need for sport performance and joint power.

And then there is the rotational or axial component, which we did not even begin to discuss here. We have briefly talked about the frontal and sagittal cylinder aspects, and yes, we have just skimmed the surface as there are multiple patterns and issues which we have had to leave out here so that this doesn’t turn into a full fledged chapter for our next book. This stuff gets complicated and can leave you running in mental circles at times.  But these concepts will help you better understand why you often see neuro-protective tightness 180 degrees on the other side of the cylinder from tightness, and when you address the weakness the other side of the cylinder some of that neuro-protective tone is eased.  But again, it is not nearly this simple because you must remember that if your assessment is static or on a table then your findings will be functionally imprecise.  And, not stopping there, there are multiple joints below the joint you are focusing on, and multiple joint complexes above as well. Plus, there are 3 other limbs that can play into the function and dysfunction of a given limb and its joints. There are breathing patterns, postural patterns and many other issues. This is not an easy game to play, let alone play it well or wisely for your athlete.

In today’s photos we wanted to show you 3 runners. One a distance runner with good joint stacking and one sprinter with amazing joint stacking.  And then the runner in the black shorts, who cannot stack the foot, knee or hips even remotely well.  This runner in the back shorts will have the cross over gait and likely have the medial ankle scuff marks to prove it. But remember, there is one component that we often talk about, one we did not discuss here … . . are there also torsional issues in this runner ? Do they have femoral or tibial torsion(s) ? What is their foot type ? Are they in the right shoe for their foot type ? Are some of these components playing into their visibly flawed mechanics ? 

Below is an article we have put up here on the blog previously.  It is a study where the investigators examined hip abductor strength (watch this video here ) in distance runners with iliotibial band syndrome comparing injured limb strength to the unaffected limb to determine whether correction of the strength deficits in the HAM’s (hip abductor muscles) correlates with successful outcomes.  The study showed the obvious, that runners with ITBS have weaker HAM strength compared to the asymptomatic leg.  

But here is our question, did they just strengthen the compensation for an apparently successful outcome, or did they address the problem ? Only time will tell if you actually fixed something or merely enabled the dysfunctional motor pattern by layering it with more armor for the next battle. If it is fixed the problem and all of its associated problems should go away. But if the runner comes back weeks later with knee complaints, foot pain, back pain or the like … . . then the message should be loud and clear.

Shawn and Ivo, The Gait Guys……today with soap on the bottom of our feet.


Clin J Sport Med. 2000 Jul;10(3):169-75. Hip abductor weakness in distance runners with iliotibial band syndrome. Fredericson MCookingham CLChaudhari AMDowdell BCOestreicher N,Sahrmann SADepartment of Functional Restoration, Stanford University, California 94305-5105, USA.