Functional Range Conditioning Review: Controlled Articular Rotations

By Skyler Zarndt MS, ATC, CSCS

Our last few posts have been a quick overview of Functional Range Conditioning’s ideas on stretching and it’s basic goals.  Today, we are going to dive a little deeper into FRC and some ideas that are unique to the program.

The definition of Controlled Articular Rotations (CAR’s) is:

Active, rotational movements at the outer limits of articular motion.

According to FRC, the usefulness of CAR’s lies in its ability to:

  • Maintain range of motion
  • Increase the health and longevity of your joints
  • Act as a screening process
  • Help in the rehabilitation process

Since we live in a modern society and don’t exactly function the way our body is supposed to function on a daily basis, we need to compensate in a positive manner for these movement deficiencies.  This is where CAR’s comes into play.  Let’s look at the 4 bullet points listed above and discuss how exactly FRC and CAR’s accomplishes those goals.


We all know that our cells are a living part of who we are.  And with that, cells must go through a process of turnover to replace, renew, and repair.  So a question that is often raised is “How do the cells know how/when to lay down new tissue?”  And the answer to that is through MOVEMENT.  Movement creates force, and force is the language of cells.  Signaling by physical means guides the remodeling of tissue.  Since we are born with a tremendous amount of movement capability, and since most of use no longer have that same capability, something must have happened to that range of motion.  Well, since we haven’t provided any FORCE cues or MOVEMENT cues to certain cells, the body has eliminated any unused ranges of motion.  All of this is through time and remodeling.  So in the exact same way as we lost our range of motion, we can hopefully regain it.

Through the prescription of Controlled Articular Rotations with consistent application, range of motion can improve or at least maintain its current state.  CAR’s provides signaling in the tissue for remodeling, engages all articular mechanoreceptors, and prevents maturation of fibrotic tissue (tissue getting “stuck”).


The causes of joint damage can be from either external and/or internal mechanical stressors.  The external factors are obviously hard to control.  But the internal factors are those we can influence.  These include tissue fibrosis (increased friction and tension) as well as uncoordinated neural activation.

Fibrosis could be defined as the thickening and scarring of tissue, or tissue that is laid down haphazardly.  This all leads to increased tissue tension.  In “healthy” tissue, all the fascia, muscle, and connective tissue slide easily.  This prevents maturation of fibrosis.

And since we are talking about joints, we have to talk about cartilage.  Since cartilage has no direct blood supply, it receives its nutrients from the surrounding joint fluid through diffusion.  And diffusion doesn’t occur without movement and pressure.  Therefore, joint health DEPENDS ON MOVEMENT!!


The screening process occurs as we go through the end ranges of motion during our CAR’s routine.  Whenever we find a range that we cannot maintain, or a range that we cannot (but should be able to) reach, then we know where we should target our movement.  Also, WHERE we feel “stuck” or “discomfort” during the CAR’s can tell us a few things as well.  For example, when many people go into a deep squat, they feel a “pinch” on the front of their thighs (impingement).  This is what is known as ABERRANT JOINT FUNCTION – articular motion that causes pain on the CLOSING side of the joint.  It doesn’t make sense from a mechanical standpoint that the closing side of the joint should hurt, since it’s not the side that is being stretched.  The limiting factor should be the tissue on the OPENING side of the joint, but many times this is not the case.  Aberrant means “divergant from the normal type.”  So our joints are not functioning normally, and this is caused by abnormal or poor neurological activation/control at the joint site.


The use of CAR’s for rehab purposes, according to FRC, are:

  • Restoring articular kinesthetic awareness
  • Neuromuscular retraining
  • Increasing passive articular strength and stability
  • Inflammation control – Movement = Anti-Inflammatory


CAR’s is ACTIVE, ROTATIONAL movement of a joint throughout the OUTER LIMITS of motion.  The “active” part is important here.  The active component of the motion is important because it ensures maximal articular feedback.  The muscles play a huge factor in keeping joints in proper position as well as control the tone of the capsule.

Rotational movements ensure that we provide the CNS with as much neural feedback as possible.  This will help ensure that our movement “hardware” is being used optimally.  Remember, if you don’t use it, you lose it.

We target the articulations of the capsule because they contain mechanoreceptors that are the first to perceive motion.  Also, unlike muscles, “capsules can provide complex multi-directional & rotational information.”

The OUTER LIMITS of the joint are stressed to ensure that all mechanoreceptors are being activated and trained.  Outer limit activation will help with joint stability as well as joint protection.


  • Morning
  • Warm up – Neural grooving
  • Habitual


  • Performed under differing levels of tension – yielding an “active” isometric component
  • Higher tensions = greater articular strain = greater mechanoreceptor activation = greater end range adaptation.
  1. inhale, trap air in lower abdominal region (irradiation).
  2. Stabilize all articulations (joints) in order to minimize movement at non-targeted joints.
  3. Begin by slowly ensuring rotation at outer limit of movement.
  4. Attempt to expand circle with each rep.
  5. For capsular CAR’s, hold the rotational contraction at end range for as long as possible.

Dr. Spina has some videos on Youtube demonstrating a few CAR’s exercises and his thoughts on using FRC as an assessment tool.  I will link below.

Tomorrow, we will discuss yet another unique function of FRC – PAIL’s and RAIL’s!


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