Rehabbing Achilles Tendinopathy

Welcome back to Squat University. Last month I started a blog series on the topic of Achilles tendinopathy. The first blog introduced a simple model to better understand why the injury process begins and how it progresses. This week I want to continue this conversation and change our focus to the treatment side of things.

Step 1: The Balancing Act

As you now have learned, tendons enter the first “reactive” stage of injury and pain is due to one simple mechanism, overload. The pain you’re experiencing started because you placed too much load on your Achilles tendon and surpassed its current “load tolerance” level. This overload may have occurred due to one specific workout (200 box jumps as a part of your CrossFit class) or it may have accumulated over a number of sessions (such as basketball player that usually trains 2-3 times a week thrust into training 2-3 times a day for 7 days during a camp). Regardless of the exact cause, the first step in decreasing symptoms is to take a step back from what caused the pain in the first place.

Now when most people think “rest” they automatically think about taking weeks away from the gym, sitting on the couch and binging on their favorite TV show. In fact, complete rest is often the first piece of advice most medical doctors give patients complaining of pain! However, this is actually the last thing we want to do. You never want to completely rest a tendon!

The strength of your tendons follow the simple motto of, “if you don’t use it, you lose it.”⁴ If you completely take away all loading and only rest for a few weeks, you set yourself up for the pain to eventually return! Like I mentioned earlier, the injury occurred because your training surpassed your current “load tolerance level.” If you completely rest for the next few weeks, your body will adapt and the tolerance level of your tendon will lower (as there is minimal load being placed on it), making it easier to overload whenever you do decide to return.

On the flip side, if you continue to push through pain and load a painful tendon, the injury will only get worse and eventually structural changes can take place in the tissues. Load management is the most important factor in recovering from a tendon injury. This is a difficult balancing act and a reason why so many people develop chronic tendon injuries.

Start by making a list of what movements, volume and intensities of exercise aggravate your symptoms. Make a separate list of exercises that you can tolerate well with no pain (while performing or the day after). Knowing exactly what brings out your symptoms will empower you to make the right adjustments for the healing process to take place.

Movements that create high loads and use the tendon as a spring (jumping or sprinting activities for example) increase cell signaling and can create the over-response that sparked the pain your feeling. Therefore, if jump rope double-unders, running hills and box jumps create symptoms, let’s take those out of your training for the time being and replace them with more low-load “tendon friendly” modes of exercise from your second list (squatting, deadlifts, rowing, etc.). Make sure to recognize the depth at which you can squat without pain. Deep squatting may be a symptom provocateur as the forward shin position can increase load on the tendon. We will gradually re-introduce these aggravating exercises back into your training as your tendons heal and adapt to tolerate greater and greater loads.

For the few elite athletes in the midst of preparing for an important competition that have no desire to take a step back from training to address their injury, you must make a change to your training program (along with adding in some of the exercises discussed later). The pain you’re experiencing is your tendon telling you it is not tolerating the loads you are placing on it. It is there for a reason. Listen to it.

For such cases, try changing one variable in your training program and see how your tendon responds. For example, if you currently train seven days a week, decrease the frequency by dropping one session. If you can’t sacrifice one day of training, you must make a change to either the amount of high intensity loads or the total volume of your training. Regardless of which variable you choose, only change one factor at a time and wait to see how your body responds (everyone will be slightly different so there is no golden rule).

Should You Stretch?

Despite what you may have learned elsewhere, we do not want to stretch an Achilles tendon injury! No matter what form of tendinopathy you may be experiencing, stretching should not be a part of your rehabilitation program.

As previously mentioned in last week’s blog, insertional Achilles tendinopathy injuries occur due to high levels of compressive load to the tendon against the calcaneus bone. Stretching your calf muscles will only serve to add more compression (and lead to more pain) on the already injured area.¹

The goal of rehab for someone with a peritendon injury is to initially limit excessive movement of the ankle (and therefore friction of the tendon against the peritendon). Stretching would only lead to creating more movement and therefore the potential for more friction.

While there is less cause for concern for those dealing with a mid-tendon tendinopathy injury, research has not shown any benefits to stretching whatsoever. This is a reason why the commonly prescribed night splints that maintain a constant stretch as you sleep are not an effective treatment for tendinopathy.

Instead, if you do have limited ankle mobility you can safely perform soft tissue mobilization to the calf muscles with a foam roller or massage stick. Foam rolling has been shown in research to improve ankle mobility without placing harmful compressive loads on the tendon.^2,3

For those with limited ankle mobility due to a joint restriction (as felt by a pinch or blocked sensation at the front of the ankle during the 5 Inch Wall Test), banded joint mobilizations can safely be performed with any form of Achilles tendinopathy. Assume a kneeling position with a resistance band loop over the top of your foot (directly over the talus bone).

With your foot firmly planted, drive your knee over your toes and hold for a few seconds before returning to the start position. The posterior and downward pull of the band against the talus while you drive your knee forward will help restore the natural movement of the ankle joint.^13,14 Perform 20 repetitions before rechecking your mobility to make sure you were efficient at bringing out any change in mobility.

Adding A Heel Raise

A heel raise insert for your shoe can be extremely helpful for certain types of Achilles tendinopathy. For example, adding a heel raise of around 3-4 cm in height will move the foot into a small amount of plantarflexion and decrease compression of the tendon against the calcaneous.¹⁵ This can unload harmful levels of compression for those dealing with an insertional tendinopathy.

A heel raise can also be helpful for those dealing with a peritendon injury. Adding the insert will decrease the amount of movement of the ankle into dorsiflexion that takes place during activity. Because this injury is often caused by excessive motion, limiting it can aid in winding down the symptoms you may be experiencing.

There is even some evidence to suggest a heel raise may be helpful at times for those experiencing pain in the mid-tendon region. A less common form of tendinopathy can occur when the plantaris muscle (a smaller muscle whose tendon runs near by the Achilles tendon) stiffens and places excessive shearing or compressive loads on the Achilles.⁵ For this reason, adding a heel raise could potentially decrease compression and therefore pain.

While a heel raise can be very helpful for some, an orthotic insert is not. Research has shown that inserts that aim to help prevent foot pronation are not effective in reducing symptoms and improving function in those with Achilles tendinopathy.

“Passive” Treatments

In the past I have had many patients come to me after failed treatments under the care of other rehabilitation professionals. When I would inquire as to what kind of treatment they went through, it often revolves around some kind of passive treatment. “Passive” treatments refer to something that is done to you where as an “active” treatment is something you physically participate in. “Passive” treatments include ice, electrotherapy, dry needling, iontophoresis, ultrasound and scraping techniques with different tools made of metal, hard plastics or bone.

Many rehabilitation practitioners will incorrectly use scraping techniques (called IASTIM or instrument-assisted soft tissue mobilization) on the painful tendon with the idea that they are stimulating collagen growth and bringing more vascularity (blood flow) to the area in order to promote healing. The first idea (stimulate collagen growth) has never been proven in a degenerated tendon, and the second idea (more vascularity) is counterintuitive as most injured tendons have already grown more blood vessels!⁶

The only way in which the technique could perceived as beneficial when applied to the tendon is in creating a possible short term decrease in pain. This change in symptoms however, would only be due to a change in how the surrounding nerves are working (called neurapraxia) as there will be little physical change to the actual tendon tissues. Performing these techniques on an already angry and reactive tendon will often do more harm than good and increase the current level of irritation. If you want to use IASTM, it should be directed to the calves and NOT to the tendon itself.

Step 2: The Rehab Plan

Exercise is the best treatment for any type of tendon pain. Period. If you have visited with a doctor or other medical practitioner that recommends injections or other “passive” treatments like electrotherapy or scraping techniques as the main mode of treatment, you went to the wrong person. While these treatments may decrease your pain in the short-term, they will not be helpful in the long-term as they do not address why your tendon became injured in the first place. You must strengthen the tendon and improve its ability tolerate load.

There is no “one size fits all” recipe program for treating tendinopathy. The program must be tailored to how your pain presents, your past injury, training history and your goals.

Phase 1: Isometrics

The first step in the rehabilitation program for almost every tendon injury is to start with isometrics. An isometric is an exercise where the muscle contracts but the joint the muscle or muscles cross does not move (no changes in muscle fiber length occur).

Early on, a very “reactive” tendon can be difficult to load with classic strength exercises due to pain. Isometrics can be a great intervention as their main objective is to decrease pain!

The body often responds to pain by inhibiting neural output (called cortical inhibition). Think about it like this. If every time you perform a jump and your body experiences pain, your brain eventually says, “stop it!” This is why someone who has been dealing with tendon pain for a long time will eventually have decreases in their performance. Heavy isometric exercises have been shown to change this.

Research shows that isometrics have the potential to decrease tendon pain for upwards of 45 minutes after performing and can improve a person’s strength thereafter by decreasing cortical inhibition! Isometrics allow you to express your strength by accessing more motor units that have previously been “turned off” due to pain. These benefits (less pain and decreased inhibition) only come with heavy and long duration (45 second) isometrics and have not been found after classic strength exercises.¹¹

Isometrics should be performed relatively pain free. While you may have a little pain at the very start, it should decrease significantly by the third or fourth repetition. For the Achilles tendon, an isometric will be a partial heel raise performed in standing. In this position you activate both calf muscles (the gastroc and soleus) and place the most amount of load on the tendon. Performing a seated heel raise isometric with your knees bent takes slack off the longer gastroc muscle (which crosses the ankle and knee joint) and therefore decreases the needed tension on the tendon to receive any of the benefits the isometrics can offer.

The way in which you perform your standing heel raise isometric however will vary from person to person depending on your current level of strength. For example, the simplest isometric for the Achilles tendon would be a double leg bodyweight heel raise. If this is too easy, perform the double leg heel raise while holding a weight in hand. For stronger athletes, a single leg heel raise or even a single leg heel raise with a weight in hand will be needed. Try each variation to find out which is difficult to perform 5 sets for a 45 second hold. Initially you should perform these exercises 2-3 times a day with a maximum 2-minute rest in between each hold.

For these exercises to be effective, they must be difficult to perform! This is where most come up short. Research shows you must find a load that contracts your muscle(s) to 70% of its max capabilities. While there is no way to test exactly for this level by yourself, you can estimate it by finding the intensity and load combination that makes an isometric difficult to hold for 45 seconds! If you finish your 45 second heel raise (either in double or single leg) and think to yourself, “I could have held that at least for 30 seconds more” … you don’t have enough load on your tendon. Grab a weight and try again!

Isometrics are to be used for every kind of Achilles tendinopathy, including a peritendon injury. While adding a heel raise to your shoe is the first step in dealing with the pain from a peritendon injury, we still need to place some load on the muscles and tendon during the recovery process. If you only rest a peritendon injury, you decrease the “load tolerance” capacity of the tendon and risk a mid-tendon or insertional tendinopathy injury when you do resume your normal training.

Isometrics are only a starting point for the rehab plan. While they help you feel better by decreasing your pain and increasing your strength, they are not the only thing you should do. At most, I would recommend using isometrics by themselves for up to a week or two weeks at maximum. Eventually we need to transition into the next phase of the rehabilitation plan.

Phase 2: Strength with Isotonics

The goal of any tendinopathy rehabilitation plan is to increase the load bearing capacity of the tendon. No matter if your injury was a first-time “reactive” or a “reactive-on-degeneration” injury, we must eventually move past isometric exercises and start using traditional strength training exercises to accomplish this.

Most exercises you see performed in the gym will have two phases: eccentric and concentric. The eccentric phase is the lowering portion of a movement where the muscle fibers are lengthened under tension. The exact opposite would be the concentric phase, where the muscle fibers are shortened under tension. If we look at the traditional standing calf raise exercise, the gastroc and soleus muscles shorten as you rise onto your toes (the concentric phase) and lengthen as you descend back to the start position (the eccentric phase).

In the early days of tendinopathy research, rehabilitation professionals prescribed eccentric exercises as an integral part of a rehabilitation program.^8,9 For an Achilles tendon injury this would consisted of performing a heel raise where you would assist yourself to the top portion with your un-injured leg, shift all of your bodyweight onto the injured side and then slowly lower into the bottom position on the injured leg alone. No concentric phase was performed, so to perform the next repetition you would then assist yourself back to the top start position again with your non-injured side. Initial research on the use of an eccentric-only rehabilitating program did show good results as many were able to return to their pre-injury activity levels.⁹

However, our body moves using both eccentric and concentric muscle actions. Focusing strength efforts on only one portion of the movement does not strengthen it in a way that will carry over functionally to the actives we perform throughout our day and in our training. Your muscles aren’t only performing eccentric muscle contractions when you sprint down a track. It’s not that eccentrics don’t work, but why ignore the other half of the movement?

In the early 2000’s research began to emerge on the use of heavy slow resistance training (HSR) in the rehabilitation of tendon injuries. HSR describes traditional exercises performed slowly with both concentric and eccentric muscle contractions (called an isotonic movement). The initial research showed these heavy and slow exercises were just as effective as eccentric only exercises in the rehab of tendinopathy.^10,12 They are excellent at building load tolerance during this phase of rehabilitation without using the tendon as a spring, which would otherwise overload the current capabilities of the tissues and increase symptoms. As soon as your pain has decreased during normal day to day function to a 3/10, I recommend starting HSR exercises.

HSR exercise should be performed to target both the gastroc and soleus muscles. While isometrics are ideally performed in the standing position only (in order to involve both the gastroc and soleus and place as much load on the tendon as possible), strength exercises need to be performed in standing and seated positions to target both muscles individually.

The seated calf raise is the most common method of isolating the soleus muscle as the larger gastroc is placed on slack with the knee bent. In order to sufficiently target the soleus muscle and place enough load on the muscle/tendon, a weight needs to be placed on top of the legs during the seated heel raise. Placing a weighted plate or dumbbell across the length of your femur however is not enough as the majority of the load will be spread across your thigh. Instead we need to place a weight directly over the top of your shin (tibia).

The way in which you load the seated calf raise will vary from person to person. Start with a heavy dumbbell stacked vertically over your knee. If the weight you choose is not sufficient to cause the desired fatigue in the muscles after the 4^th set of 10 repetitions, you need to either increase the weight of the dumbbell or place a loaded barbell across your knees.

To target the gastroc muscle, perform standing heel raises while holding weight. The double leg version will often be the easiest and can be progressed to single leg. Remember to perform both the seated and standing calf raises with a very slow tempo (three second eccentric lower and three second concentric ascent) with as much weight as you can tolerate and maintain good technique.

In order to really benefit from HSR exercises, you must perform them slowly and heavy! Sounds simple enough, right?

The “slow” portion of HSR refers to the tempo at which the exercise is performed. Ideally, you should take three seconds in the eccentric and three seconds in the concentric phase (meaning each rep takes 6 seconds total to complete).¹⁰ The “heavy” portion of HSR refers to the intensity of the exercise or how much weight is being used. This is the factor most rehabilitation professionals unfortunately come up short as they are afraid to load the injured tendon! Don’t be! Remember, even a degenerated tendon has more “healthy” tissue than a normal tendon.¹⁷

When you’re starting the HSR phase of the rehab plan, start with 4 sets of 15 repetitions every other day (on your off days continue to perform the isometrics from phase one). Perform your isometric exercises prior to any HSR as the cortical inhibition benefits derived from the isometrics will allow you to access more motor units and therefore a greater strength stimulus.

The weight you choose to perform the exercise with should be something you can control with good technique for each repetition, but heavy enough to where after completing your fourth set you are too fatigued to perform a fifth.⁷ If you get done with your fourth set and feel like you have enough energy to perform a fifth, add more weight! It is rare to have a lot of pain with HSR exercises if you’re doing them slow enough (if you do, you may not be experiencing a true tendinopathy injury and you may want to revisit the diagnosis section of the prior blog).

Research on the use of HSR with tendinopathy has recommended performing these strength exercises for 4 sets of 15 repetitions for 1 week before increasing the weight and dropping the volume to 4 sets of 12 reps for the next two weeks.¹⁰ Eventually progress to 4 sets of 10 reps, followed by 4 sets of 8 and then 6 reps (each for 2-3 weeks each).

Along with the HSR component to strengthening the muscles/tendon complex, we also need to increase the ability of the tendon to absorb and store loads. The highest loads placed on the Achilles tendon occur when we use it as a spring, utilizing what is called the stretch shortening cycle (SSC).

Powerful movements (like running or repetitive jumping) use the tendon to store and then release energy in order to generate large amounts of power. Exercises that emphasize the storage of loads (such as a jumping from a box and landing) are therefore a bridge to eventually returning to the full energy storage and release capabilities of the tendon.

Stand on a small box, maybe 6-8 inches in height. Step off and land with both feet in a mini squat position. Don’t land with stiff joints but instead make sure to absorb the force of impact. Perform two sets of twenty landings to start before progressing according to how your body responds to a higher box and eventually a single leg landing.

Phase 3: Plyometric  

In order to start plyometrics (where the tendon is used as a spring to store and release energy) we must first see profound changes in muscle strength. The strength of the injured leg must be close to the capabilities of the non-injured extremity. Those who have been experiencing chronic Achilles tendon pain may have acquired noticeable differences in muscle size (noted calf atrophy of the injured leg) however, muscle size changes will take much longer compared to strength and is not the best predictor of when to return to plyometric loads.⁷

A great way to assess your level of strength is to perform the same testing protocol from the prior blog. Perform 20 double leg heel raise followed by 20 single leg heel raises. Look and feel for how easy it is to perform the movement on each leg. Is it the same? Was there any pain?

Next, perform a faster more explosive movement like a single leg hop on each leg. Originally this movement was likely painful and hard to perform on the injured leg. If you are ready to move onto the plyometric phase of rehab, you must have the ability to show good quality control of your body without any pain during slow movements like the single leg heel raise and a high load functional movement like a hop.

The goal with this phase of rehab is to start using the tendon as a spring again and see how it responds. An example of an entry level plyometric will be a double leg pogo hop. Simply perform repetitive small jumps only a few inches off the ground (like bouncing on a pogo stick). Start with 30-50 reps in a row before resting for a few minutes and perform 3-4 sets. If you can perform pogo jumps without any pain, try a a few light jogs (1-minute duration at maximum).

Notice how your tendon responds to the loading during and within the next 24 hours. If you feel great during and do not have any increase in tendon pain or stiffness the following day, increase the training load the next session. For the first few weeks, increase the volume of your loading by adding in more jumps per set or doing longer runs to help build your tendon’s capacity.

Recording every aspect of your plyometric program will allow you to progress and build this capacity as efficiently as possible. For example, Athlete A and Athlete B both performed 3 sets of 30 pogo hops and 3 sets of 1 minute jogs the first day. Athlete A woke up the next day and felt great, so he was allowed to progress to 3 sets of 50 pogo hops the next session while keeping the running the same. Athlete B however woke up the following day and had a slight increase in his Achilles tendon pain. For this reason, Athlete B’s plan would need to be modified the next plyometric (either dropping volume on the hops or jogs).

Make sure to only increase one variable each training session (whether that’s adding or taking away volume or intensity). If you change too many variables you won’t be able to go back through your notes and see whether it was a loading change in volume or intensity that was too much for your tendon to handle.

Start with two to three sessions a week of these light plyometric (one session every three days). At this stage of rehabilitation, the tendon cannot take plyometric loads everyday without getting angry. For this reason, structure your weekly training by mixing HSR days in between plyometric sessions. If your tendon continues to respond well to the increases in plyometric loading every third day, you can continue to add more volume or start to increase intensity.

Eventually you’ll be able to progress to medium level plyometric exercises including squat jumps, jump rope, and double leg jumps for distance. If you are a runner (or have any running in the sport you participate in) adding in acceleration and deceleration drills along with cutting/change of direction activates may be a good option at this time.

After a few weeks of progressing these drills, you can then move to even higher level plyometric activities including: single leg pogo hops, double under jump rope, sprinting mixed with agility drills and longer distance runs. For anyone participating in the Olympic lifts of the snatch and clean, I recommend waiting until this time to reinitiate the full lifts as the explosive nature of the movement coupled with the loaded barbell may be too excessive for the tendon to handle before this time.

Eventually you can start manipulating the frequency of loading by performing plyometrics every two days instead of three. As always, see how your tendon responds and adjust accordingly. There is no perfect recipe for how to progress though this plyometric stage. Everyone will respond differently and you need to find what loads work best for your body. Be patient at this time, this process can take several weeks to months.

Final Thoughts

The rehabilitation process for a tendon injury can be boiled down to one simple sentence, “Err on the side of caution.” There’s no doubt if you’re reading this blog it’s because you are trying to find the most efficient and quickest way to fix your pain and return to the activities you love. I urge you to take this process slowly and have patience. Depending on the severity of your tendon injury, this process could take months.

I hope this blog post could be helpful in giving you a better understanding of the complexity of Achilles tendinopathy rehabilitation. If you at any time feel like you are not progressing well with trying to work through this process on your own, I strongly recommend contacting a rehabilitation professional to help you through this process.

Until next time,

With

 

References

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16. Munteanu SE, Scott LA, Bonanno DR, Landrof KB, et al. Effectiveness of customized foot orthoses for Achilles tendinopathy: a randomised controlled trial. Br J Sports Med. 2015;49(15):989-94
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