What causes Achilles pain after an ankle sprain?

Achilles pain can develop for a number of reasons following an ankle injury, and this pain may be located in the tendon itself, or on its attachment to the back of the heel bone.

First, it depends on what the type of sprain occurred, as the mechanism of injury for different sprains will place a different amount of stress on the Achilles tendon.

Lateral Ankle Sprains

For the most common type of ankle sprain, which is an inversion ankle sprain, also known as a lateral ankle sprain, the Achilles often isn’t forced into a position will it will sustain damage. As such, severe Achilles tendon injuries aren’t very common with lateral ankle sprains.

Lateral ankle sprains result from forced inversion of the ankle, and if any other direction is involved, it is usually plantarflexion, which places the Achilles tendon in a shortened position, meaning it is usually not prone to being over-stretched.

So why can it hurt after this type of injury?

Actively using the calf muscles, and thus the Achilles tendon, will result in the motion of ankle plantarflexion (“pressing the gas pedal”). If the anterior talofibular ligament (ATFL) is damaged, which is one of the main lateral ankle ligaments, putting the ankle in this position may cause pain to the injured area, and as such, this movement is not performed to its full degree for some time.

Once getting back into these motions, the Achilles tendon will require a progressive reintroduction to loading, so if activity that uses and stresses the Achilles tendon is introduced too quickly, it may begin developing Achilles tendinosis, which is an over-use type of injury that involves breakdown and disorganization of the collagen fibers in the tendon.

In other words, tendons don’t like surprises, so if a tendon is loaded too much too quickly, whether or not a concurrent injury is present, it may react in a painful manner.

Medial Ankle Sprains

Medial ankle sprains are similar to lateral ankle sprains, just switch the location of damage and mechanism of injury to be the opposite. In this case, the ligaments on the inside of the ankle are damaged as a result of forced ankle eversion, which usually doesn’t place too much stress on the Achilles tendon itself.

For the same reasons listed above, the Achilles tendon may be provoked if it has rested for a while and then is suddenly exposed to significant loading, especially with weight bearing activities that involve plantarflexion and dorsiflexion motions.

The same principle of avoiding surprising the tendon will apply in this case as well.

High Ankle Sprains

A high ankle sprain usually results from the foot being planted on the ground and being forced into an externally rotated and dorsiflexed position. The anterior inferior tibiofibular ligament is most commonly affected, which is a ligament that helps support the distal ends of the tibia and fibula (shin bones) by holding them together. Forced external rotation and dorsiflexion will put a lot of stress on this ligament, which is why it’s most commonly injured in a high ankle sprain.

Given that there is a component of forced dorsiflexion, it is entirely possible that the Achilles tendon sustains acute damage as well, as the dorsiflexed position places this tendon on stretch, and the calf muscles are likely contracting at the same time in attempt to resist this forced motion.

Therefore, the calf muscle and/or Achilles tendon may be acutely damaged as well with a high ankle sprain, but if it is, it’s usually not to the same extent as the anterior inferior tibiofibular ligament.

Additionally, a high ankle sprain often requires immobilization in walking boot, often for about 6 weeks. If the ankle is stuck in this position for a while, regaining ankle range of motion after the fact may not feel great on the Achilles tendon at first. Also, just like we mentioned above, resuming lots of activity too quickly, especially in weight bearing, may surprise the tendon leading to pain.

Inflammation and Secondary Injury

While the mechanism of injury associated with some ankle sprains is less likely to injure the Achilles tendon, it’s always possible to sustain secondary injury to this tendon or its associated calf muscles, especially if the injury was severe or complex in nature. For example, the calf muscle or Achilles tendon may become strained when attempting to resist the forces that caused the sprained ankle.

Strains are usually partial, meaning there is some tearing in the muscle or tendon. A fully strained Achilles tendon is referred to as an Achilles tendon rupture, which means it’s completely “blown”. An Achilles tendon rupture would likely be the primary complaint after the injury, or at least a big complaint along with a concurrent injury, so it’s unlikely to miss, but it’s worth pointing out nevertheless.

One of the main things patients report with an Achilles tendon rupture is the sensation that someone kicked them in the Achilles tendon or back of the heel bone.

In terms of inflammation, this is the first phase of healing that occurs after an acute injury, and this is amplified in severe ankle sprains. Inflammation can lead to more generalized pain throughout the ankle, or if the tendon is directly affected, may lead to Achilles tendinitis, which may cause pain or discomfort when using the Achilles tendon, especially after a concurrently sprained ankle.

How can you prevent Achilles pain after an ankle sprain?

The easiest way to prevent Achilles pain after a sprained ankle is to follow the guidance of your physical therapist, as they will have a strategic approach to not only treating the damaged ankle ligaments, but to preventing the development of secondary issues like Achilles pain.

Foot Intrinsic Strengthening

During the initial stages of rehab when we still need to focus on protecting the ankle, it’s important to keep up with strengthening the small intrinsic muscles of the foot. This can be done by performing exercises that involve the toes and arch of the foot, such as towel scrunches, toe fanning, and short foot doming.

This will help maintain a solid foundation for the foot and ankle (Lee and Choi, 2016), so once weight bearing status is increases, the foot will be well equipped to handle the load, thus indirectly reducing the stress placed on the Achilles tendon. It will also reduce the stress on the plantar fascia, which can also assist in addressing pain on the heel bone itself.

Guided Range of Motion

Ankle range of motion exercises can often be started shortly after an ankle sprain, but this may seem very gentle at first, especially in the case of severe sprains, as we want to ensure we maintain an optimal environment for ligament healing and reduction of inflammation.

This is the reason we specify “guided”, as a physical therapist can assess your specific ankle injury and provide appropriate guidance on how much to move the ankle and what motions to avoid.

This may begin with exercises like tracing the alphabet with your foot and ankle within a pain-free range of motion. This will help gently move structures around the foot and ankle, including the calf muscles and Achilles tendon, and will also help provide a starting point to the restoration of ankle proprioception, which in over-simplified terms, can be though of as a combination of joint position awareness and balance.

Other exercises like ankle pumps (moving the foot/ankle up and down) within a pain-free range of motion will also help to ensure we keep the calf muscle active and expose the Achilles tendon to the motions it will need to accommodate you progress through the rehab process.

A bonus to this exercise is that it can help prevent the development of blood clots, specifically deep vein thrombosis, especially in situations where you are not able to walk on the ankle for a given time.

Taking Strength Seriously

While progressing through rehab for a sprained ankle, the ankle itself should feel better over time. By the time a patient receives clearance to begin more advanced strengthening for the ankle, it’s likely that their ankle is feeling pretty good, and as such, isn’t always top of mind.

This is a part of rehab where patients are at risk of falling off, which can increase the risk of chronic ankle pain and dysfunction, as well as future ankle injuries.

Therefore, it is imperative to continue with the strengthening protocol during your ankle rehab to rpevent this type of chronic ankle pain, as this will help build the appropriate support around the ankle, thus reducing the stress on the ankle joint and Achilles tendon.

Additionally, many of these exercises will challenge the calf muscles, and as such, progressively load the Achilles tendon in a way that it can safely and effectively build up the tolerance to the types of activity that you’re trying to get back to.

Examples of ankle exercises that specifically load the Achilles tendon include various forms of calf raises, multi-joint movements on your feet like various forms of squats, and eventually more intense exercises that involve jumping, running, or change of direction.

Build Ankle Rehab Into Your General Fitness

When you get back to feeling 100% for the very first time following an ankle sprain, it’s important to consider that you just got there. One way I personally word this to patients is to envision that you’re hanging by a string. Sure, it’s supporting you for now, but we want to make sure that we turn that string into a nice solid rope to ensure we minimize the risk of future pain and/or injuries.

This doesn’t mean you have to do boring resistance band exercises forever, just that you need to keep your ankle in mind when you are participating in general workouts. General strategies include, but are not limited to:

– Don’t skip leg day!

– Maintain ankle range of motion by routinely stretching your calf muscles, which can help prevent the development of Achilles pain after an ankle sprain.

– Routinely perform more general ankle exercises, for example, calf raises or single balance on an unstable surface.

– Wearing an ankle sleeve or lace-up ankle brace during more high-impact activities.

How can you treat Achilles pain after an ankle sprain?

If Achilles pain does occur after an ankle sprain, specific strategies to reduce this pain can be identified by your physical therapist, as the treatment method will depend on the exact source of the pain. That said, here are some general strategies that are often used to resolve these issues:

Soft Tissue Release

Soft tissue release or massage can help reduce the tension in calf muscles that haven’t had to function as normal during the recovery process. This can be a helpful way to help loosen up the muscle without placing stress on the Achilles tendon itself.

This can be done by rolling out the calf muscles on a foam roller, or performed by a healthcare professional that is qualified to deliver this type of treatment, such as a registered massage therapist (RMT), physical therapist, or chiropractor.

Dry Needling

If taut bands or trigger points are identified in the calf muscle, dry needling may be used to help normalize the tone in the muscle, which can help with passive muscle stretching and muscle contraction of the calf muscle (Albin et al, 2020). Again, this can be done in a way that does not place physical stress on the Achilles tendon itself.

Many physical therapists are qualified in dry needling techniques, but not all of them are, so it’s worth inquiring ahead of time if this is something you think you might be interesting in.

Ice

If the Achilles tendon appears red or swollen, it may be inflamed, and as such, ice can be a helpful thing to apply to the tendon. Ice can also help reduce pain by overriding the nerves carrying the pain signals, so it can with both direct reduction in pain as well as reduction in inflammation.

Please refer to our article that discusses safety consideration for application of ice before application.

Shockwave Therapy

Shockwave is a clinical tool that is primarily used to treat tendinopathies. This tool is applied over the skin and delivers high intensity sound waves that propagate into the tendon tissue, which ultimately stimulates healing of the tendon.

Shockwave therapy can be quite uncomfortable and isn’t an all-encompassing treatment for Achilles tendinopathy, but it can certainly provide clinically meaningful improvements in symptoms associated with Achilles tendinopathy, specifically the reduction in pain over time (Gerdesmeyer et al, 2015).

Your physical therapist will be able to identify if this is a valuable tool for your specific Achilles tendon pain.

Strengthening

Often times, the reason people develop Achilles pain after an ankle sprain is because the calf muscles never returned to full strength, and as such, the Achilles tendon is more vulnerable to overuse (Mahieu et al, 2006).

This can lead to conditions like Achilles tendinopathy, which is a catch all term closely related to Achilles tendinosis. In the case of Achilles tendinosis or tendinopathy, the best way to achieve a permanent solution is to specifically load the tendon, which comes in the form of strategic and specific calf strengthening exercises. This is often referred to by clinicians as a heel drop program.

It may seem counterintuitive to strengthen a muscle and tendon complex that feels stiff and sore, but given the cause of the pain is reduced capacity to withstand daily forces placed on the Achilles tendon, it is very important to follow the guidance provided by your physio when it comes to strengthening.

Stretching

Aggressive stretching should be avoided if your Achilles pain is specifically due to Achilles tendinosis; however, if the ankle is simply dealing with some residual post-injury stiffness, stretching the calf muscles can help reduce the tension and pain in the Achilles tendon.

In this case, general calf stretches may be recommended, but it’s important to remember that you can stretch different calf muscles specifically.

For example, to place an emphasis on the gastrocnemius muscle of the calf complex, the calf stretch should be performed with the knee fully straightened. To emphasize the soleus muscle of the calf complex, performing a calf stretch with the knee bent will reduce the stretch on the gastrocnemius and increase the stretch on the soleus.

Summary

This article discussed different reasons that people develop Achilles pain after an ankle sprain, how to prevent the onset of this pain, and ways to treat this pain should it already be present. Like any other injury or condition, it is important to seek in-person guidance from a physical therapist to ensure your rehab is safe and effective, and to ask questions along the way, as this knowledge may help you develop self-management strategies down the road.

References

Albin, S. R., Koppenhaver, S. L., MacDonald, C. W., Capoccia, S., Ngo, D., Phippen, S., … & Hoffman, L. R. (2020). The effect of dry needling on gastrocnemius muscle stiffness and strength in participants with latent trigger points. Journal of Electromyography and Kinesiology, 55, 102479.

Gerdesmeyer, L., Mittermayr, R., Fuerst, M., Al Muderis, M., Thiele, R., Saxena, A., & Gollwitzer, H. (2015). Current evidence of extracorporeal shock wave therapy in chronic Achilles tendinopathy. International Journal of Surgery, 24, 154-159.

Lee, D. B., & Choi, J. D. (2016). The effects of foot intrinsic muscle and tibialis posterior strengthening exercise on plantar pressure and dynamic balance in adults flexible pes planus. Physical Therapy Korea, 23(4), 27-37.

Mahieu, N. N., Witvrouw, E., Stevens, V., Van Tiggelen, D., & Roget, P. (2006). Intrinsic risk factors for the development of achilles tendon overuse injury: a prospective study. The American journal of sports medicine, 34(2), 226-235.

Disclaimer:

The content here is designed for information & education purposes only and is not intended for medical advice.