I will be spending a few posts now on the importance of measuring achilles strength. By far the strongest tendon in the body, I have watched its power and majesty, and I have watched what happens when weakest sets in. It is so easy for you to become modern day specialists in achilles health, which I have eluded to in 2 prior posts. Today, we will begin our discussion on achilles flexibility. Your measurement, which may be slightly different than mine, should be done the same way each time. You need to achieve intraexaminer reliability, which just takes attention to detail and practice. Therefore, if you measure a 5 degree improvement in a tight achilles tendon in 3 months, it does not matter if I would have measured a 6 degree change or a different range. In fact, our physical therapy staff will always measure 10 degrees more than I, but if they are reliable to themselves, if they measure a five degree change during the treatment, I am happy. For me that change was -2 to +3, and to them 8 to 13. I only ask in my Rx to get me 5 or 6 more degrees of dorsiflexion (typically a tight achilles will gain 2 degrees per month while in a rehabilitation program).
You may ask how is strength related to flexibility. Every tendon has a certain length, called its resting length or normal physiological length, where the neuromuscular charge is the best. As a muscle gets tighter, the charge lets weaker, and you are called "muscle bound". As muscle gets too stretched out, the charge also becomes weaker, and your tendon becomes like cooked spaghetti. We need our patients in that middle ground. For the gastrocnemius, the middle ground is 10-12 (what I strive for), but 7 to 14 is probably fine. For the soleus, the middle ground is 15-18 (which I strive for) but 13 to 21 is probably fine. This is totally based on my experience, and allows for variances in measurement also between you and me.
Now, let's look at our 2 classic measurements. Again, if we want to achieve intraexaminer reliability (your job and in your control), every measurement is done the same. It should also be at the same time of day, which is impractical, so just know the average patient gains 2 degrees throughout the day even without stretching as they warm up.
Image above shows our measurement of the gastrocnemius flexibility. How I do it? Get down on your knees as your eyes have to be on the same plane as your measurement. One arm of the tractograph along the lateral side of the foot (lateral heel to 5th met head bisection, and one arm of the tractograph bisects both the lateral malleolus and head of the fibula. You load the medial plantar side of the foot to prevent pronation as you first begin to dorsiflex the foot at the ankle passively, then ask the patient to help you without allowing the foot to pronate. You then take your measurement.
This next photo just below has my head down for the camera focus only. Again, you are at the level of your examination, one arm lateral foot and one arm lateral malleolus to head of the fibula, slightly load plantar medial and begin passively to dorsiflex. Then, ask the patient to help in the dorsiflexion while you maintain pressure under the first metatarsal which helps you ascertain if the patient is trying to pronate, which you can resist, to gain my dorsiflexion of the foot on the leg. Now, take your measurement.
Let us look at several measurements taken on 3 separate patients on the injured right side only.
Patient #1 8 to 12 (meaning gastroc measurement was 8 degrees and soleus measurement was 12 degrees.
Patient #2 -2 to 18
Patient #3 19 to 27
Patient #1 very close to normal, but encouraged straight and bent knee stretching once a day for basic maintenance.
Patient #2 very tight gastroc, normal soleus, so recommended only straight knee gastrocnemius 3 times a day. Followup to measure in one month.
Patient #3 overly flexible gastroc and soleus, stopped all stretching, and only allowed twice daily gastroc and soleus strengthening via straight and bent knee calf or heel raises. Followup to measure 1 month.
https://youtu.be/0eAqJ4-oKTM?si=HNICL3V_ZOpJ1eX_
https://youtu.be/53AXlas2q6s?si=iGjkK_j30aJ0s6iV
