Copied from a Previous Post (this post will be a continuation)
The achilles tendon, like the patellar tendon and the hamstrings, are primarily sagittal plane movers. The more you put them in the center, not deviated in the transverse and frontal planes, the better they work. Dr. Steven Subotnick, Podiatrist out of Hayward, California, was the first to describe the importance of this centering for achilles problems in the 1970s to me. Designing CFOs that hold the heel near subtalar neutral and tibial-calcaneal neutral, can have great influence on achilles rehabilitation.
These 3 images emphasize the pull of the achilles when the heel to leg alignment is (left to right): heel everted to the leg (achilles contracting with a potentially twisted alignment), heel centered to the leg (best position for sagittal plane motion), and the heel inverted to the leg (also twisted while contracting).
The achilles is the strongest tendon in the body, and therefore asked to move heavy loads (up to 11x body weight). How can we help this tendon out, as our athletes require it to perform great tasks? We can measure flexibility, and keep the tendon from being too tight or too loose. We can measure its strength (typically by the ability of one-sided straight knee and bent knee heel raises), and encourage the maintenance of optimal tone. We can design orthotic devices with the emphasis on subtalar neutral positioning. We can encourage shoes with good heel lift for stressful activities (10 mm heel drop or more).
New part of the Achilles Discussion
So, how can we help this great tendon stay healthy, and functioning at its highest level? If we summarize the above, we should actively do the following. These are:
- Make sure we are designing foot inserts to attempt a better centered heel. Easy to measure how far from center the patient is functioning by using the Achilles Angle (tibial calcaneal angle) with the patient in relaxed calcaneal stance position. The left side I am measuring the resting position, with the right side you can measure the angle between the tibial bisection and the heel bisection with a tractograph. Some patients you can get this angle to 0, but most you want a positive change between no orthotic device and standing on their orthotic device.
2. We can measure both the gastrocnemius and soleus flexibility for both tightness (that needs to be stretched out), and over flexibility that needs to be tighted up. You all know the standard range of normal based on one of the four current methods used. When the tendon is too tight from normal, we need to encourage a good stretching program for the patient. When the tendon is too loose from normal, we need to temporarily stop all stretching and begin an active strengthening program. The image below is my normal achilles examination with the knee bent, and the subtalar in neutral non weight bearing. All exam methods should be able to pickup their share of loose or tight tendons.
3. Another important component of achilles health is its overall strength. Again we have to differentiate the gastrocnemius and soleus. Typically the soleus is weaker, but the debate ranges from 50% to 80% of gastrocnemius strength. I like to keep a 50% ratio at least with the gastroc doing 50% more single heel raises than the soleus. You disengage the gastrocnemius when the knee is bent 15-20% degrees. Therefore, heel raises (aka calf raises) are done with the knee straight for gastroc and knee bent for soleus. Gold standard for strength is 25 single heel raises knee straight, and 12 single heel raises with knee bent. Here soleus bent knee strengthening is being shown.
4. I think there will always controversy over the shoe aspect of achilles health, but I prefer a heel elevation in shoes. If someone recently got an achilles injury, no matter how minor, I would put them in heeled shoes for all their activities, including clogs at home with no barefoot walking. If you prefer the zero-drop shoes over the traditional running shoes (with heel elevations up to 1/2 inch), then your breakin should be very slow over 3 months. I always prefer my runners rotate between types of shoes that I have helped them select due to stability issues. If your achilles starting getting sore, and the Rule of Thumb: Look at an Achilles Cross Eyed and it will hurt for 9 months, immediately stay in your more traditional shoes for 2 weeks longer than you need. The classic minimalist or maximalist shoes have zero-drop or very low heel heights. The Hoka below is a maximalist shoe with 4 mm heel height and late MetaRocker.
Next post I will discuss the Rule of 3 of athletic injury. One of my favorite topics that has served me well. The basic concept is that it takes 3 or more stresses acting together to cause an injury. This post just showed a very common situation where a patient have 4 issues that lead to the breakdown and injury of their achilles tendon:
- Malalignment between the heel and achilles
- Overly tight or loose achilles tendon when flexibility was measured
- Overly weak in the soleus when asked to perform single leg heel raises knee bent position
- An recent change from traditional running shoes with 12 mm heel drop to zero drop running shoes
