The Achilles tendon: a skier’s most neglected point of weakness

I love writing on topics that combine injury rehabilitation, skiing, and current events. With real-life Achilles himself, American Olympic alpine skier Steve Nyman, recently tearing his achilles tendon and undergoing surgical repair, it seems like the appropriate time to discuss this injury and its associated rehab. This article can help you reduce the risk of this injury occurring or, in the unfortunate event you share the same injury experience as Mr. Nyman, it can improve your return back to snow. I will paint a clinical picture of this injury, the treatment options, provide an overview of the rehabilitation, and identify the criteria needed to safely return back to skiing.

Achilles tendon injuries are the number one reported overuse injury in the literature, and is most commonly experienced by middle aged runners and rock climbers, affecting more males than females, and surprisingly is the third most common injury suffered by World Cup skiers after knee sprains and low back pain.^1-6 The knees, hips, and core get the most love during strengthening and conditioning, and the achilles tendon becomes the “red-headed stepchild” of training leading it vulnerable to injury. There are two common locations where achilles tendon injuries occur: 1) at the achilles tendon about 2-6 centimeters above the insertion of the achilles tendon (aka mid portion tendinopathy), and 2) as it inserts into the heel bone (i.e. insertional tendinopathy). 

Both types of injuries can have two possible outcomes. First, and the most common type, are sprains of the tendon or muscle varying from mild to severe. This type is observed more frequently in training than in competition as a quick ramp up in the former can cause unsafe loading and shearing forces on the achilles tendon.⁶ The second type of achilles tendon injury is a complete rupture of the tendon. This occurs most commonly in men and women between the ages of 20-40 years old during competitive or recreational activities such as skiing, running, or hiking and accounts for 15% of all tendon tears that occur per year in the United States.⁷ Risk factors that correlate to achilles tendon disorders include limited ankle dorsiflexion range of motion, decreased calf strength, increased foot pronation (flat foot posture), obesity, and runners who demonstrate a “heel-strike” pattern.⁸ Adress each of these risk factors to help reduce your risk of this injury. 

A complete rupture like what happened to Mr. Nyman is going to immediately sideline a skier. But even a mild to severe sprain can sideline 50% of skiers for at least 8 days, with 25% of skiers missing greater than 28 days, and the average time to recover being 82 days.^9,10 Athletes such as skiers who try to come back before 8-10 days after an initial injury have a 27% higher risk of re-injury.^9,10 Returning too soon can also make the injury worse by turning it from a mild or moderate sprain to a severe sprain which leads to 38% of these people requiring surgical intervention.¹¹   

There are two treatment options for the different kinds of achilles tendon disorders. Conservative treatment is the recommended choice for mild, moderate, and a majority of severe tendinopathy injuries, and surgery has been the choice for some cases of severe tendinopathies and for full tendon ruptures. Since Mr. Nyman’s injury I have been asked more, “do I need to get surgery for a full tear”? At first the question may seem silly with traditionalists exclaiming, “it’s a full tear, it won’t heal on its own, of course you need to get surgery.” But, upon more investigative research into the outcomes following surgical repair for a torn achilles tendon, the question should not be dismissed out of hand. 

While there is a 5.1% lower rate of re-rupture for those who choose operation compared to non-operation, there is a statistically significant increase in the risk of other complications following surgery with infection being the most common at 2.8% of the time.^12-14 Now, that may seem like an unfair argument since postoperative complications will always be a risk if you choose surgery versus nonsurgery. But, add to the clinical picture that long term functional and return to sports outcomes appear to be the same for both groups, with each returning to sports at the same pre-injury competitive level within 6-9 months, and can it turn the question into not having a straightforward answer.^12-14

If you’re Steve Nyman then of course you should choose the surgical route. He is the definition of an elite athlete in a sport that requires incredible physical strength at fast speeds. Surgery is the right recommendation for Steve as well as any highly active athlete who demands early return to extremely strenuous sports at an elite competitive level. The choice becomes more debatable for recreational skiers between 40-60 years old with non-acute injuries. After all, the lower rate of other complications following non-operative treatment might outweigh the relatively small benefit of lower re-rupture rate in surgical cases. 

Achilles tendon injuries are more of the mild to moderate variety that require conservative treatment and not surgery, so the former will be discussed in more detail but there is definitely overlap between the two. As an overview the intervention needs to be broken down into two different phases: acute and non-acute. The acute phase is defined as the injury occurring less than three months ago, high levels of pain limiting low level activity (e.g. walking, stairs, transitional movements), redness, warmth, and swelling. The non acute phase is defined as the injury occurring greater than three months ago, onset of pain after completing higher level activity, and no redness, warmth, or swelling. What is the best recommended course of treatment for both of these groups?

Pain Control and Inflammation

The best available evidence to guide decision making for pain control and inflammation in the acute phase is using iontophoresis with dexamethasone (yes that same dexamethasone being discussed to treat the coronavirus but in a different form). In the non-acute phase you should be implementing mechanical loading exercises (such as heel raises) progressing from concentric to eccentric under load with slow movement. 

Loss of Range of Motion (ROM) or Painful Motion

While there is a lack of great evidence, there is still a consensus amongst experts that soft tissue mobilization and rigid taping (not therapeutic taping like KT tape) can help with loss of motion and painful motion respectively in both the acute and non-acute phase. What I find interesting is that a lot of popular interventions lack evidence to support its use including PRP injections, corticosteroid injections (initial short term benefit only), night splints, heel lifts, orthotics, and laser therapy. So, why do many people “run” towards these options? I believe the passivity of the treatment is desirable: ”just throw in an orthotic and forget about it” or “just lie there and hit me with a laser” or “just gimme the injection doc”. The only fad, passive treatment that is recommended with some credible evidence is extracorporeal shock wave therapy but only when combined with eccentric exercise for people with chronic midportion achilles tendinopathy.  

Education and Counseling

Surprisingly, the other intervention that ranks above the previously mentioned ones with a moderate strength of evidence is education and counseling. Contrary to popular management of this condition complete rest is not indicated, and people should continue their recreational activity within their pain tolerance or less than 5/10 on the pain scale (0 being no pain and 10 being take me to the hospital right now). This applies to both the acute and the non-acute phases of the injury. 

Therapeutic Exercise

The biggest categories to rehab and train in order to facilitate a return back to snow are flexibility and strength.

Flexibility

The most important flexibility to regain in the foot, ankle, and calf following this injury is ankle dorsiflexion (i.e. the ability to lift your foot up towards your shin). This can be achieved by stretching the calf muscles, the plantar fascia of the foot, or improving the mobility of the actual ankle joint using exercises such as the classic runner’s stretch with the knee straight and the knee bent, rolling out the bottom of the foot with a ball, and squatting with the heels elevated but progressively lowering the height to increase the mobility respectively. A barometer of functional ankle mobility for skiers is to perform a modified weight bearing forward lunge test and achieve 30-50 degrees of ankle dorsiflexion by measuring with a digital inclinometer.  

Heel Raise Strength

The most classic example of mechanical loading for the calf and the tendon is a heel raise. The heel raise needs to be performed in two different positions: with the knee straight, and the knee bent. The knee straight is to target the top layer of the calf for power and speed (i.e. the gastrocnemius) and the knee bent is to target the bottom layer of the calf for postural stability and balance (i.e. the soleus). Both types of heel raises should start in a non weight bearing position such as sitting in a chair and then progress to standing up on level ground to then performing a “negative” heel raise on an elevated surface. You should progress in this order with both legs performing the heel raises together before performing on just one leg. Perform the heel raises with 2-3 sets of 25-30 repetitions counting 1 second to lift the heel(s) up, and a 6 second count when lowering your heel(s).

Sport Related Strength

It also becomes important to strengthen the calf muscles in positions that are vital to skiers including squats, split squats, and deadlifts.  You can perform squats on level ground or on an incline/decline board, a split squat with the front limb heel off the ground and either the front or rear leg elevated, and a single leg deadlift. One of my favorite late stage rehab exercises that requires both strength and balance of the calf muscles is a cross body step up into a single leg heel raise. You should be doing your exercises to first have endurance strength with a volume of 2-3 sets of 25-30 repetitions. Then you need to convert that endurance strength to power-endurance strength. 

Plyometric Power Strength

plyometric impact exercises such as pogo hops can be a great exercise to improve the power-endurance strength of the calf muscles and achilles tendon. It’s an explosive calf raise by executing a jump with only your ankles and keeping the knees straight. The parameters skiers should think about when performing this exercise is duration and should safely be ramped up to match the average time it takes to complete a ski run at a frequency that matches the rate of turns completed (roughly 1.5-2.5 seconds per turn). This exercise can be progressed to hopping side to side, rotationally, alternating between feet, single leg hops, and with added weight. I believe a good barometer for return back to snow is performing 40-60 weighted (30-50% of body weight) split squat jumps at a frequency of 1.5-2.5 seconds within tolerance during and after the exercise.  

I hope this helps you in either preventing future injury or managing a current achilles tendon injury. I wish Steve Nyman the best during his recovery and any other skier going through the same or similar injury. If you have any questions, comments, concerns, feedback please drop a comment below and I will be sure to answer. 

References

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9. Lemme NJ, Li NY, DeFroda SF, Kleiner J, Owens BD. Epidemiology of achilles tendon ruptures in the United States: Athletic and nonathletic injuries from 2012 to 2016. Orthop J Sports Med. 2018;6(11):1-7. 
10. Nielsen RO, Ronnow L, Rasmussen S, Lind M. A prospective study on time to recovery in 254 injured novice runners. PLoS One. 2014.
11. Gajhede-Knudsen M, Ekstrand J, Magnusson H, Maffulli N. Recurrence of achilles tendon injuries in elite male football players is more common after early return to play: an 11-year follow-up of the UEFA Champions League injury study. BR J Sports Med. 2013.  
12. Maffulli G, Del Buono A, Richards P, Oliva F, Maffulli N. Conservative, minimally invasive and open surgical repair for management of acute ruptures of the achilles tendon: a clinical and functional retrospective study. Muscles, Ligaments and Tendons Journal. 2017;7(1):46-52. 
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14. Reda Y, Farouk A, Adbelmonem I, Elshazly O. Surgical versus non-surgical treatment for acute achilles tendon rupture: a systematic review of literature and meta-analysis. Foot and Ankle Surgery. 2019; Accepted manuscript. DOI: https://doi.org/10.1016/j.fas.2019.03.010.