Welcome to the Podiatry Arena forums

You are currently viewing our podiatry forum as a guest which gives you limited access to view all podiatry discussions and access our other features. By joining our free global community of Podiatrists and other interested foot health care professionals you will have access to post podiatry topics (answer and ask questions), communicate privately with other members, upload content, view attachments, receive a weekly email update of new discussions, access other special features. Registered users do not get displayed the advertisements in posted messages. Registration is fast, simple and absolutely free so please, join our global Podiatry community today!

  1. Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
    Dismiss Notice
Dismiss Notice
Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
Dismiss Notice
Have you liked us on Facebook to get our updates? Please do. Click here for our Facebook page.
Dismiss Notice
Do you get the weekly newsletter that Podiatry Arena sends out to update everybody? If not, click here to organise this.

Inaccuracies In Subtalar Joint Neutral Theory Dogma

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Kevin Kirby, Apr 14, 2007.


  1. Members do not see these Ads. Sign Up.
    It has now been 17 years since I first reported on the following inaccuracies in the dogma taught by the proponents of the subtalar joint neutral theory (Kirby KA: Foot and Lower Extremity Biomechanics: A Ten Year Collection of Precision Intricast Newsletters. Precision Intricast, Inc., Payson, Arizona, 1997, pp. 7-12). Does anyone have any more inaccuracies to add to my list or does anyone disagree with any of these observations I made way back in 1990. (You old-timers may need to help out the younger podiatrists/students who weren't taught this stuff like I was back in the 1980s.)

    By the way, is subtalar joint neutral theory still being taught in any podiatry schools still? :confused:

    1. The calcaneus must be in the vertical position while in relaxed calcaneal stance position in order for the foot to function normally during gait.

    2. Each foot has only one correct heel bisection.

    3. If a calcaneus is everted by more than two degrees then it will continue pronating until the maximally pronated position of the STJ is reached.

    4. A functional foot orthosis made from a cast of the foot held in the STJ neutral position will position the subtalar joint in the neutral position while in stance and/or in gait.

    5. The standard biomechanical examination yields sufficient information to predict how that particular individual's lower extremity will function during gait.

    6. Forefoot deformities (i.e. forefoot varus, forefoot valgus) are congenital disorders.

    7. A functional foot orthosis must be made from a rigid thermoplastic without forefoot extensions. Cork and leather orthoses are not functional foot orthoses.

    8. If a patient stands in relaxed calcaneal stance position with the calcaneus inverted then there must be some abnormality causing the calcaneus to not be vertical (i.e. an inverted calcaneus is always abnormal)

    9. A foot with an everted forefoot to rearfoot relationship should be treated with an orthosis which is balanced with the heel vertical.
     
  2. Admin2

    Admin2 Administrator Staff Member

  3. Kenva

    Kenva Active Member

    Kevin,

    As we spoke about this on your visit, we do give SJN Root theory in our first year. Probably due to the fact that we don't have any (almost any) good orthtotic labs to produce orthotics like we want them to be.
    First year students now learn to take a neutral cast, plaster correct them and make a basic 'Root' concept orthotic. We hand these skills trough the work of Root and it makes a good basis/concept for 'looking at a foot'.
    It takes a bit of mental strength to struggle with different types of new methodologies provided in the literature...
    We chose to start somewhere, and up to the day that somewhere was the basis where the initial podiatric shift started -being Root...

    Cheers

    Ken

    27° out here, who would have said that a couple of weeks ago ;)
     
  4. Scorpio622

    Scorpio622 Active Member

    Kevin,

    I'm sure I could think of many more, but three come to mind:

    1) There IS a neutral position that can be measured accurately (reliable and
    valid) and has clinical relevance.

    2) There should be twice the amount of supination than pronation from said
    neutral position.

    3) The margins of error the orthotic lab will experience when making the
    positive cast, pressing the shell, and adding the prescribed posting-not to
    mention the variances in the shoes the orthotics are used in- will be
    negligible and not change the intended positioning of the leg / rearfoot /
    forefoot which is typically measured within a small margin of degrees
    (measured by a goniometer that has at least a 5 degree margin
    of error) while I continue to dream in technicolor......

    Nick
     
  5. Kirby Weather Station in Sacramento

    Ken:

    It was 24 degrees Celsius (75 degrees F) here today in Sacramento. In fact, Ken, anytime you want to know the weather conditions here at the Kirby house in Fair Oaks (a suburb of Sacramento), you can check the conditions at Kirby Weatherpod Weather Station. I have a weather station that reports the most current conditions every 5 seconds to the internet here at my home in Fair Oaks.
     
    Last edited: Apr 16, 2007
  6. Ken:

    I have no problems with the clinical concept of the subtalar joint (STJ) neutral position as long as we aren't trying to be too scientific about it. In other words, the STJ neutral position is not an absolute position within the range of motion of the STJ, it can not be precisely defined and can not be reproducibly measured by multiple examiners. Therefore, the STJ neutral position is probably OK for clinical work, but not OK for scientific research.

    Here is how I use the STJ neutral position on a daily basis on my patients:

    1. To assess forefoot to rearfoot relationship.

    2. To assess nonweightbearing ankle joint dorsiflexion.

    3. To perform plaster of paris suspension casting for custom foot orthoses.

    However, my list of innaccuracies gives you a much better idea of the problems with Root's theories. I hope you provide my list to your students before they graduate from Podiatry School so they can all have a better idea of the reality of how the foot really works during weightbearing activities.
     
  7. There is a neutral position of the STJ since Root has defined it (Lee WE: Podiatric biomechanics: an historical appraisal and discussion of the Root model as a clinical system of approach in the present context of theoretical uncertainty. Clinics Pod Med Surg, 18 (4):555-684, 2001). However, the problem is that no two examiners can always agree on where the STJ neutral position is within the range of motion of the STJ and the definition of STJ neutral position as given by Root is a circular definition with imprecise meaning. I do believe STJ neutral does have clinical relevance since it is a good marker for a midrange position of the STJ.

    This is again one of the claims made by Root et al. However, I agree that it is not always the case since I commonly see ratios of pronation:supination of 1:4 and 1:1 rather Root et al's 1:2 by the method I use to determine STJ neutral position.

    This is not a problem only with STJ neutral theory but is also a problem with foot orthosis therapy in general. Huge problems will arise when one makes the assumption, as proponents of the STJ neutral theory have, that by performing goniometric measurements of the foot and lower extremity that an optimum foot orthosis design may be achieved 100% of the time.
     
Loading...

Share This Page