ACHILLES TENDINOPATHY

Last year I wrote a blog for Unite Health on Achilles Tendinopathies, which I thought I'd share here.

Achilles tendinopathy truly can be the Achilles heel of many long distance runners due to the increase in load, both in frequency and duration of running, which occurs in preparation for a marathon.  A typical presentation for Achilles tendinopathy is pain directly over the mid-portion of the Achilles, especially in the morning and more so the day after running.  If the pain is more towards the insertion of the Achilles tendon into the bone, this is known as an Achilles enthesopathy.  In both cases, it is important to be mindful not to overstretch the calf under load as this can cause compression of the tendon onto the bone – i.e. doing your calf stretches off a step is not advised as this can potentially cause the tendon to compress the bursa beneath or irritate the Kager fat pad.  Self massage or rolling the calves out with a foam roller is a safe way to loosen the calves.

ADDRESSING PROXIMAL CONTRIBUTORS TO ACHILLES TENDINOPATHY

When an individual experiences pain, often the immediate reaction is to stop doing the activity that causes pain.  However, research suggests that in order for tendon adaptation to occur, it needs to be loaded (Bohm et al. 2015).  This may sound a contradiction to the above, which states that Achilles tendinopathy is a load injury, but it comes down to effective load management.  That is, firstly we may need to look at the individual’s running gait and assist with creating a movement strategy that shifts load away from the injured Achilles.  Often in clinical practice I see individuals with tight calves and Achilles issues who have very poor glute max activation and strength.  This means that their hip extension strategy to give them their drive forwards is too reliant on the calf rather than efficiently using the proximal (and much larger) glutes for power.  The APPI clinical reasoning model can be a powerful tool in understanding why they might have inefficient glutes and therefore overload of the calf and Achilles, which in turn makes it easier to develop their rehab program.  Is the individual overactive and tight through their hip flexors, making it more difficulty to engage their glutes? If so, Swimming L4 is a fantastic exercise to challenge the glutes through a range that they are more likely able to control (from flexion to neutral).  Or is the individual an “active extender” with over-active deep longitudinal sling (erector spinae and hamstrings) making it more difficulty to get the correct balance of glutes:hamstrings for hip extension?  If so, exercise such as Roll Up can help to achieve lumbopelvic disassociation, encouraging the individual into lumbar flexion and challenging the individual’s anterior trunk muscles to reduce over-reliance on posterior muscles.  They may then be given Shoulder Bridge to continue this theme of spinal mobility and working on hip extension being driven from the glutes rather than hamstrings.

EDUCATING YOUR CLIENT

Educating your client on volume and frequency of training is often the simplest and most effective way to address overload.  A general guide to exposing yourself to gradually longer runs is to increase the time/distance of your “long run” by no more than 10% each week, and limiting your frequency to 3-4 runs per week.  If the client presents already with a grumpy Achilles tendon, rather than telling them to stop running all together, enquire how long it takes in a run for their pain to come on – if they report that once warmed up their pain dissipates but after 30min pain returns, then limit their current running to 25-30min, 3x week.  As their Achilles strengthens and they become more biomechanically efficient with cross-training rehab then they can gradually begin to increase duration again.

ACHILLES TENDON LOADING PROTOCOL

Including at least one heavy load rehab exercise into your program for the Achilles will encourage changes to mechanical and morphological properties of the tendon, which will influence tendon stiffness.  It is recommended that high loading intensity of >70% MVC and >70% 1RM over 12 weeks is necessary in order to produce effective tendon changes (Bohm et al. 2015).  The traditional Alfredson protocol recommends 180 repetitions per day, however recent research suggests that an “as tolerated” program with fewer repetitions can achieve similar results for mid-portion Achilles tendinopathy (Stevens et al. 2013).  As such, depending on the patient’s tolerance, a program that includes both knee straight and knee bent eccentric heel drops can be prescribed with up to 3 sets of 15 repetitions for each, daily.

The goal is to perform a controlled, slow lower of the heel off a step while standing on the injured foot.  Starting with the ankle plantarflexed (rising up on the toes) the heel is lowered down into dorsiflexion.  The non-injured leg is then used to assist you back up to the top of the calf raise.  It is normal to feel some pain during this exercise and it is ok to work through mild discomfort, but not severe pain.  The exercise is designed to selectively cause some damage to the collagen fibres of the tendon, removing misaligned tendon fibres and laying down healthy collagen in the matrix of the tendon.  Once full dosage can be achieved pain free then load can be added through weights in a backpack to progressively strengthen the tendon.  For individuals who have an insertional Achilles issue (enthesopathy) the above protocol should be modified to flat ground, slowly lowering from raised or plantarflexed position to neutral, and only performed with the knee straight.

TAKE HOME MESSAGE

In summary, key points for managing Achilles tendinopathy patients:

1) Prevention is best – educate clients to gradually build load and encourage cross training for strengthening proximal muscles.
2) Look proximally at contributing factors to the development of an Achilles tendinopathy and address these imbalances.
3) It is ok to keep running with Achilles tendinopathy as long as volume and frequency are addressed.
3) Incorporate a heavy load Achilles exercise into rehab program, such as eccentric heel drops.

REFERENCES

Bohm S, Mersmann F and Arampatzis A (2015), Human tendon adaptation in response to mechanical loading: a systematic review and meta-analysis of exercise intervention studies on healthy adults. Sports Med – Open 1:7

Stevens M and Tan C-W (2013). Effectiveness of the Alfredson Protocol Compared With a Lower Repetition-Volume Protocol for Midportion Achilles Tendinopathy: A Randomized Controlled Trial. Journal of Orthopaedic & Sports Physical Therapy, 44(2):59–67