Achilles Tendon Injuries

Diagnosis and Treatment
by Dr. Kent Kurfman
originally published in Pace Running Magazine Winter 2014

AchilliesGraphicAfter a long summer of preparation for peak performance, Fall is a prime time for runners and triathletes to develop problems with their Achilles tendons. The combination of mileage and speedwork can catch up with any of us, leaving a runner with a sore, stiff Achilles, sidelined and wondering both how he got in this state and what can be done to get over it. Fortunately, there is plenty to do to correct Achilles injuries – careful attention to training, to the idiosyncrasies of your body, to your selection of footwear and to your plan when injured will help you weather this problem and return to racing.

The Achilles is a unique structure, even among tendons. Tendons provide a unique function in connecting muscles to the bones and joints that they move. In the case of the Achilles, and the gastrocnemius and soleus muscles attached to it, it acts as a dynamic “spring.” Research on this indicates that the Achilles is an “energy return” system, giving back 40-50% of the energy loaded into it during each stride. It is estimated to be able to resist up to seven times one’s body weight loaded through it during a forceful push-off.

Tendons, like most other tissues in our body, are in a constant state of turnover. Our bodies break down collagen bundles with the wear and tear of running and rebuild it with new collagen, maintaining a constant balance. We injure our tendons when our training becomes excessive and the process of breakdown occurs more rapidly than our bodies can repair the tendon. At this point, one’s Achilles is injured. Our terminology for these tendon injuries has changed along with our understanding of the nature and progression of the injuries. What we once labeled as tendinitis, we now call tendinopathy. Traditionally, tendinitis referred to an inflamed tendon. In recent research on tendon problems, we now understand that tendinitis refers only to tendons during the acute stages of injury, typically the first three or so weeks after the onset of pain, swelling and stiffness. When looking microscopically at chronically injured tendons, what often is found is not inflammation but rather tendon degeneration. This includes irregular collagen fiber alignment, pockets of mucus-like material, and excessive blood vessel ingrowth – all evidence of poor tissue healing and a tendon too weak to handle the stresses of training, much less daily standing and walking.

Although athletes at any level or age can injure their tendons, chronic Achilles tendon injuries are more common in older runners. According to Taunton (2002), who wrote one of the classic studies on running injuries, the averages on this are that runners tend to be older (40.7) and have been running longer (14.5 years) – all the accumulation of wear and tear. Other risk factors include intrinsic problems, like your weight, whether you pronate too much, or your calf muscles are short and hinder your ability to dorsiflex (bend your ankle) during stance. There are also extrinsic problems – how you train (such as your mileage and the intensity of your training), the amount of rest between workouts, how much sleep you get, the shoes you use, and even the use of fluoroquinolone antibiotics. Your previous injuries play into this as well, including any form changes you inherited from your last injury and whether this Achilles injury is your first or not. Probably the biggest risk factor for an Achilles tendinopathy is having experienced a previous Achilles injury.

Diagnosis and treatment
How a physician or therapist directs the treatment of an Achilles tendon injury is determined by an accurate diagnosis of the problem. Treatment for these problems is very specific, based on whether it is an acute (first few weeks) or chronic (months or longer) injury and what part of the tendon is injured, the mid portion, its attachment to the heel (enthesis), or both. We need also to make sure that we screen out other problems that can mimic an Achilles tendon injury, things like injury to the posterior tibialis tendon, bursitis around the Achilles (retrocalcaneal or superficial calcaneal) or posterior ankle impingement. In my practice, we spend time with a careful examination to determine the specifics of the injury, looking at things such as your running gait, your footwear use, your flexibility, strength, balance and joint integrity. Getting the problem accurately assessed is critical.

Part of this assessment is based on staging the injury. For the last several years, physicians and therapists have relied on the work of Cook, Purdham and Alfredson, Achilles tendon researchers who have developed the concepts of staging tendon injuries (reactive, tendon disrepair, degenerative tendinopathy) and directing the treatment of these injuries.

The initial stage of an Achilles injury is the reactive stage. The tendon swells, and becomes hard and stiff in the first few days of being overworked. Clinicians like to catch problems at this stage because tendon injuries are most easily managed early. Ice, rest, and even the use of NSAIDS (as directed by your physician) have the most “bang for the buck.” At this stage, most runners with an injured Achilles tendon can be quickly helped, if they are careful to follow the standard RICE (Rest, Ice, Compression, Elevation) guidelines.

The next stage of tendon injury runs between the acute reactive stage and degenerative tendinopathy and is termed tendon disrepair. Runners reach this stage when they don’t carefully manage their tendon pain during the reactive stage. During tendon disrepair, the tendon begins to change and becomes weaker as the body starts the process of rebuilding. Cook refers to tendons at this stage as “grumbly.” Small changes in your activity level aggravate them. They become stiff when getting out of bed or up from a chair after sitting or driving. These tendons usually feel lumpy with nodules rather than being firmly swollen. We see most runners at this stage and it is where we develop an individual-specific program.
The final stage is degenerative tendinopathy. The runners that we see at this stage are usually the older endurance athletes who have sustained multiple bouts of Achilles tendon injury and who never seem to heal. I described this stage earlier, where the tendon’s collagen fibers are arranged irregularly, with mucoid pockets, extra blood vessels, and nerves all present. The tendon is not strong enough for the stress of running regularly.

Based on the severity of a runner’s symptoms, we lump these three classifications into two, with the reactive stage and early disrepair tendons treated differently from those with longer-term tendon disrepair and degenerative tendinopathy. If it sounds complicated, it can be, as each runner comes with his own set of characteristic problems and his symptoms will vary between stages based on how hard he is training.

For the reactive stage and early disrepair stages of Achilles tendon injury, in addition to the RICE guidelines, we add in controlled loading exercises. Low load training, using isometrics, helps to control Achilles pain and stiffness and to improve tendon healing. The instructions I give runners at this stage are to start adding a gentle double leg heel raise with a 60 second hold to their daily activities – this should be repeated 10 times during the day. They should self-massage the tendon (rubbing crossways over the tender areas with light to moderate pressure) for five minutes at least once a day as well. Once a runner’s overall symptoms decrease to a “3” on a 0-10 pain severity scale, he can start a gentle program of run/walk training for 10-15 minutes (usually with a cycle of 1 minute run/1 minute walk). The key with progress in this stage is to make sure to space one’s runs out at least 24 hours between training sessions. Tendon pain responses tend to be delayed by several hours after stress/exercise, so it is important to keep the pain low-level (no greater than 3/10) and not to limp.

For the later disrepair and chronic tendinopathy stages, treatment becomes more aggressive. For the past several years, the research on Achilles tendinopathy has supported using controlled loading via eccentric (“negative” exercise) training as the cornerstone of treatment. For most runners, this means we have them perform heel lifts where they raise up on both toes, lift up their un-injured foot at the top of the heel raise and lower just on the injured side. Pain is expected during this exercise program; if there’s not some discomfort, the guidelines are to add resistance (holding a dumbbell or wearing a backpack) so that some discomfort is present. In this way, we know that the tendon is being properly stressed. We modify this program based on the location of pain. When the mid portion of the tendon is injured, these heel raises are performed off the back of a step.

When the attachment at the heel is the injury site, we keep the runner flat on the floor or even in shoes to keep from compressing the deeper portions of the tendon. These programs have high success rates, as long as a runner is patient enough to stick with them. The baseline program is typically two sessions of exercise (3 sets of 15 reps) per day for three months or more. As you can see, these treatment decisions require skill and are why you need to seek professional help when you have a chronic Achilles injury.

Ancillary treatments can be an important help with most Achilles injuries. One of these is kinesiotaping – a light tension adhesive strip drawn from the calf over the tendon to the base of the heel often helps to ease pain and seems to help limit superficial tendon swelling – enough to lessen limping. A second one I use (selectively) is instrument-assisted soft tissue mobilization, also known as Graston technique. It also helps to lessen tendon pain and speed healing responses. I usually have runners with calf inflexibility issues use a foam roller or lacrosse ball to improve calf mobility and plantar fascial mobility. But, I am careful to stress with them not to stretch their calves – typically, this will slow the healing process, as it places compressive stress at the deeper portion of the Achilles at the heel.

With runners with excessive pronation, I use an orthotic device in selected cases. Despite the research indicating that overpronation is poorly associated with running injuries, there is other research showing that lessening pronation in some runners improves their symptoms. As far as shoe selection, I prefer to use a flexible, neutral trainer for most runners with Achilles tendon problems. The heel counter becomes more important, particularly if it is too stiff and curves into the heel – some shoes need “surgery” to trim the counter and heel tab to keep pressure off the Achilles. Gait retraining is very important with many of these runners. The most common gait fault noted is an over-aggressive toe- off, excessive vertical oscillation and a fully extended knee at toe-off, all signs of trying to use calf strength to drive the stride rather than gluteal/hip extension and the natural elastic return of the Achilles. All of these runners need to work aggressively on gluteal strengthening, as the control and power at their hips will prevent them from driving too vigorously with their calves. Indeed, a very recent study (Smith, Medicine and Science in Sports and Exercise, October 2013) studied gluteal muscle activation in runners with Achilles injuries and showed it to be delayed and shortened.

Finally, in regard to running during the later/chronic stages of Achilles injury, we surprisingly will usually counsel runners to keep running. This advice often flies in the face of common sense for many, but it is backed by research. Silbernagel’s research in The American Journal of Sports Medicine (2007) indicated that if an individual monitors his symptoms carefully (no training with pain greater than 5/10 in severity), there is no difference in the long-term outcomes between those who rest and those who keep training. Considering that most runners are at greater risk when they ramp up their training after a break, keeping up training as long as one’s running form isn’t compromised and symptoms aren’t worsened, seems a logical conclusion.


Kent Kurfman, PT, DPT, OCS, MTC, has been a physical therapist for 24 years and an avid runner for 35 years. He oversees the Running Academy at Proaxis Therapy, a multifaceted program of running injury prevention and treatment. He continues to race regularly, including four finishes at the Boston Marathon.

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