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Saturday, October 22, 2022

Relaxed Calcaneal Stance Position: One of the Most Important Measurements made by Podiatrist

  Relaxed Calcaneal Stance Position

     Measurement showed over 10 Degrees of Heel Everted Positioning

     The Relaxed Calcaneal Stance Position (aka Resting Position or RCSP) is utilized for understanding of Pronation Syndrome, Supination Syndrome, Poor Shock Absorption, Limb Length Discrepancy compensations, Tight Muscle compensations, Weak Muscle gait patterns, and other issues. Therefore, I always perform this test due to its importance. Here are some images showing how to bisect the heel in a prone position before standing the patient up (my preferred way). 

Here is the Typical Starting Point of Bisecting the Heels for Subtalar ROM and RCSP or NCSP with the Patient Prone Heels Angulated

It is so Crucial to Make Sure the Posterior Surface of the Heel is Aligned (Parallel to) with Your Eyes so the Opposite Leg is Bent and Externally Rotated and the Patient may need to roll over on their hip (side being measured)

By Palpating the Medial and Lateral Borders of the Heel Three Times from Superior to Inferior The Examiner can Bisect the Heel

Here is a Close Up of My 3 Bisection Points and the Solid lines represent the Medial and Lateral borders of the Posterior Surface which are Divergent (They are Never Completely Rectangular)

Here the Bisected Heel on the left is Stood Up and the Heel is Measured either Vertical, Inverted, and Everted (The Right Side will be slightly to significantly different to the Left Side)

     This crucial examination technique is to bisect the center of the heel prone, and then stand the patient up and see if the heel is vertical, everted, or inverted. This test can also be done with the patient standing, but I prefer to start with the patient prone. This is very useful in the initial evaluation for orthotic devices in writing your prescription to make a biomechanical change. It is also used when orthotic devices are dispensed, by having the patient stand with and without their orthotic devices to check if the orthotic corrections are achieving the desired results. However, you also have to correlate standing correction to walking change to make sure that they substantiate each other. One of the highlights of my career is when I use a relaxed standing position measurement to follow the development of a growing child as I progress to less pronated feet through orthotic support (as originally taught to me by the renowned Dr. Ronald Valmassy). It is also used in the preoperative and postoperative evaluations of flat foot surgeries. And, as you can see from the syndromes that it helps with at the start of this discussion, it can really help you understand a lot about the biomechanics of a patient. The change in the relaxed calcaneal stance position can help you understand corrections in pronation, supination, compensations for short leg syndrome, if someone is a poor shock absorber, if I am supporting a posterior tibial tendon dysfunction patient enough, or allowing a genu varum patient to have less stress on their knees, etc. I would put it as my number one test overall. 

     The posterior surface of the calcaneus or heel bone is usually flat and will be angled from posterior lateral to anterior medial on weight bearing (and this does not take into account the angle of gait). You must keep the posterior surface of the heel bone in line with your eyes. You must find the medial and lateral borders of this posterior surface and put your fingers so they align right along those borders from superior to inferior. 

Fingers Flush with the Medial and Lateral Calcaneal Borders and 3 Points Placed 1 inch Apart to Bisect the Heel

Your fingers should be flush with the medial and lateral borders in the middle of the calcaneus from superior to inferior, and clearly just on the medial and lateral edges, not on the posterior surface of the heel bone. Then make 3 points about one inch (2.5 cm) apart from superior to inferior bisecting the two sides.

After Each Dot Applied Continue to Check the Sides to Make Sure of Your Bisection

Medial and Lateral Borders Checked Against Your Bisection Points

2 Bisection Points Made

When Placing Your Points, Leave One Hand on One Side to Not Lose Your Reference

Here All 3 Points are Checked with the Medial and Lateral Heel Sides to Insure a Great Bisection

After the 3 Points, Draw a Straight Line Connecting the Points

     Draw a straight line downward connecting these three points. This can be done weight bearing or non-weight bearing (one method will feel easier to you although I prefer non-weight bearing). When you are learning, do this and other measurements with others to see if you agree. Examiners when learning this technique tend to align/favor one of the two borders, even when those borders are divergent. When the patient is non-weight bearing, please remember the posterior heel is best measured when completely parallel to the plane of your eyes, so angle their body to bring the posterior surface to this reference (helped by bending the opposite knee and placing over the knee on the side you are examining). The typical orientation of the posterior heel’s medial and lateral edges will be like a rectangle with straight parallel edges, or more rhomboid with divergent edges (as in the photos on this page). After a few feet, students get the feel of this quite easily. It is such an important measurement that you should check your line several times.

     Once the heel has been bisected, extend the line as straight as possible another centimeter superiorly and another centimeter inferiorly. When the patient stands, look at the back of the heels and make sure your line looks straight all the way from inferior to superior, and make sure the line looks like it matches what the heel looks like (you will be able to see vertical, inverted, or everted heels without lines someday). By this I mean, when you stand several feet behind the patient, does the heel and line both look straight, both everted, both inverted from right to left, or with asymmetrical feet some combination of these 3 positions. With weight bearing, use an angle measuring device that is parallel with the posterior surface of the heel running posterior lateral to anterior medial (I use both a tractograph and an app called Bubble Level XL). Now you are ready to measure the heel position to the ground. This measurement is typically done without orthotic devices, called the resting calcaneal stance position, or resting heel position. But, it is used to see how your orthotic devices, or surgery of some sort that should affect the heel, has done its job. An orthotic device, even with a deep heel cup, will not distort this line. 

Measurement of RCSP using Bubble Level XL app

Here the same measurement staying on top of custom orthotic devices

     What are common examples of the use and meaning of the relaxed calcaneal stance position, or simply the resting heel position? First of all, your definition of the heel as everted, inverted, or vertical speaks volumes. I think it is fine to just estimate how far from the heel neutral position it is at this early point in your evaluation (heel neutral is where the subtalar joint has been placed in its neutral position). This will be based on your estimating the amount of tibial varum or valgus, and influenced by genu varum or valgus.  This estimate will talk about compensations, and I like them to make sense. They can also mean injury, like when a heel is more inverted then it should be from peroneal tendon or lateral ankle ligament damage, or the heel is more everted than it should be from the advancement of posterior tibial tendon dysfunction stages. The common examples of RCSP that influence my orthotic decision making include:

  • 7 degrees everted in resting with normal /foot and leg structure (why so everted is the question?)

  • 7 degrees everted in resting with genu valgum noted (is the eversion all because of the knee valgus deforming force?)

  • 4 degrees inverted in resting with severe genu valgum noted (is the inverted RCSP compensation for the knee valgus?)

  • Vertical heel in resting with high tibial varum noted (is this vertical heel position also its maximally pronated position?)

  • 4 degrees inverted in resting with normal foot and leg structure (why so inverted is the question?)

Normal Left Biomechanics Structurally doesn’t Explain 4 degrees RCSP inverted positioning

  • 3 degrees inverted in resting with tibial varum noted (does the foot have the ability to get back to vertical or is it in its maximally pronated position?)

Our examination at this point is just the beginning of our understanding. 

     There will be 2 standard variations of your RCSP measurement that are commonly done. The first was popularized by Dr Kevin Kirby’s Maximum Pronation Test. It is very important to know if the patient is standing maximally pronated (for injury evaluation and treatment) no matter if the RCSP is vertical, inverted or everted. You measure the RCSP first as just described, then you ask the patient to attempt to lift up their lateral metatarsals off the ground while keeping the knees straight. If the RCSP does not evert more than 2 degrees further, you can assume the patient is functioning maximally pronated. You then measure the second RCSP no matter what and record the degrees. Then, and only if the RCSP is inverted, you ask the patient to rotate their bodies from the hips internally as far as they can without lifting off their feet, to see if this internal or pronatory force can bring the heel more towards vertical. This is a version of the Coleman Block Test which lifts up under the lateral forefoot with a ¼ inch pad or wedge to see if the inverted heel can be made straight (crucial in supinators when you are designing a possible orthotic device to bring them at vertical). There will be more on these concepts in the orthotic prescription chapter. 

     Max Pronation Test (described by Dr Kevin Kirby) is done by first measuring the RCSP and then having the patient attempt to lift up the outside of the foot (more pronation) by firing the peroneus brevis. Dr Kirby first shows the patient the foot motion desired by moving his hands. You then measure the RCSP again. An alternative is to have the patient internally rotate the entire limb, one side at a time, and again measure the RCSP. A change of 2 degrees or less in the RCSP means that the patient has been functioning maximally pronated.

     Here the RCSP is inverted with all the symptoms of over-supination (discussed further in Chapter 9 of Book 3). In an attempt to help this patient, you want to find out if the patient can be pronated with an orthotic device or valgus wedge closer to the vertical heel. The Coleman Block Test uses a wedge under the lateral forefoot to attempt this change in the RCSP, or the patient can also be asked to internally rotate the entire limb to maximally pronate the subtalar joint. The RCSP should be measured each time you attempt a change and compared to the normal RCSP. 

Inverted RCSP, but can it get to Vertical for orthotic ordering

Exact degrees measured

Examiner’s hand under the 4th and 5th metatarsal heads simulate the Coleman Block Test (heel easily everts to heel vertical and beyond)

Everything measured

This is an excerpt on an examination technique discussed in both of my Books 1 and 2 of "Practical Biomechanics for the Podiatrist"

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Thank you very much for leaving a comment. Due to my time restraints, some comments may not be answered.I will answer questions that I feel will help the community as a whole.. I can only answer medical questions in a general form. No specific answers can be given. Please consult a podiatrist, therapist, orthopedist, or sports medicine physician in your area for specific questions.