The Hruska Clinic Integrator
Hruska Clinic's Jason Masek Introduces the 10-20-30-40 Concept
Posted on 02/18/2016
As a Postural Restoration clinician we are always looking at various relationships and how these relationships influence other systems and/or parts of the human body. I am going to introduce the 10-20-30-40 concept which equates to 10 degrees of dorsiflexion, 20 degrees of hip extension, 30 degrees of hip adduction, and 40 degrees of hip internal rotation. In other words, you have to have at least have 10 degrees of dorsiflexion of the ankle to obtain 40 degrees of hip internal rotation. Likewise, you have to have 10 degrees of ankle dorsiflexion to obtain 20 degrees of hip extension. I think you are seeing the "pattern" you need at least 10 degrees of ankle dorsiflexion in order to obtain optimal extension, adduction, and internal rotation about the hip without compensation throughout the lower kinetic chain. I will discuss the normal mechanics and compensations in a later blog but today i would like to pay respect to ankle dorsiflexion.
Reduced "push" from our feet equates to compensatory pull from our hip flexors and back extensors. Optimally an individual wants the push to come from our hamstrings, gluteals, and abdominals. If an individual is placed in a sub-optimal position such as limited dorsiflexion a multitude of compensations will occur above the ankle joint. If you have limited dorsiflexion, the "KNEES DON'T BEND". I will discuss this knee bending business in a later blog but here are some things to consider prior to the next blog that have been researched with regard to limited dorsiflexion.
-- Limitation of ankle dorsiflexion makes it impossible to adopt the squatting knee
flexion posture. (Jali et. al., 2010)
-- Greater dorsiflexion ROM is associated with greater knee-flexion displacement and smaller
ground reaction forces during landing (Fong et. al., 2011)
--The ankle is responsible for support throughout stance. Thus a loss of ankle function
impairs support and alters propulsion, requiring compensations at other joints.
(Riley et. al., 2001)
So in closing, it is a matter of the starting "position" that will influence the "position" and/or movements or lack there of other respective joints. For example, "Inhalation= Ribs Up= Plantarflexion" and Exhalation=Ribs Down=Dorsiflexion". I will discuss these relationships in another blog!