Achilles Tendon Blog by Nick Knight

A blog about Achilles tendons was suggested by an UKRunChat community member, so here goes. I did tell myself by trying to keep it shorter than my last blog, unfortunately I have failed! (It is slightly longer than some essays that I wrote at university) hopefully is all informative for you guys. So grab a coffee and a banana (healthy biscuit) and have a read.

I imagine a few people reading this, will have or are suffering with an Achilles injuries, this is a subject where the research is constantly evolving. It is a vast topic and you could easier write 20,000 words on it, however I shall include some tips at the end of where you can read more if interested.

A systematic review in the British Journal of Sports Medicine in 2011, showed that Achilles tendon injuries were the 2nd most common musculoskeletal injuries in long distance runners. There are many myths in this area, for which some are still been used in the medical world, which creates confusion within the patient population. The aim of this blog is to try and dispel some the myths and offer a bit of advice around treatment. However as always my advice is seek professional advice. See a professional, get a diagnoses, get the right treatment.

Lets start off with some anatomy of the Achilles of the tendon and muscles leading into it. Above the Achilles tendon we have the calf muscles made up of Gastrocnemius, Soleus and Plantaris (though not everyone has one of these) Below the Achilles tendon we have the plantar fascia. The importance of this is that the calf muscles, Achilles tendon and the plantar fascia are all one structure.

The Achilles Tendon is split into 3 sections
1) Tendo-muscular Junction
2) Mid Portion
3) Insertion

Image from Eorthopod

From my experience and what I see in clinic, I see more mid portion Achilles tendinopathy.
This leads nicely onto my first myth and note I said tendinopathy and not tendonitis. We now know (and have for a while now) that the pain runners tend to get in the Achilles tendon is not related to inflammation, thus we have stopped calling it tendinitis. However Tendinitis can still exist, though this is normally found in people with inflammatory arthropathies, like rheumatoid arthritis. Despite this knowledge the term tendinitis is still unfortunately at times.

The majority of Achilles tendon injuries are due to the fact that the Achilles tendon has been exposed to excessive load, in relation to what it is capable of tolerating. This may well have been caused from in a sudden increase in mileage, rest from running then too quick return, change in altitude i.e. incorporating more Hill running, changing running technique, we know that forefoot running increases the load and stiffness within the Achilles, change in footwear etc. Or it can be a one off trauma.

It is important to remember that tendon pain will not always hurt at the time of loading, the classical tendon pain presentation is, stiffness the following morning and onset of pain between 24 – 48 hours after stopping activity, this is a sign that the tendon has been overloaded and appropriate load management is required, the earlier you can catch the tendinopathy the better.

A colleague of mine Dr Simon Spooner described a nice and simple way to help try and explain how a structure can get overloaded, and coined the term zone of optimum stress (ZOOS) and linking this with Scott Dye’s work from 2005 we can begin to paint a picture on how we can become injured. If we begin to load the Achilles tendon outside of its ZOOS it will eventually become injured, when this happens the tendons ability to handle the load reduces, this is a nice way to explain that whilst your Achilles pain started some time ago, day-to-day walking and activities are enough now to expose the tendon too excessive loading. This can be a repetitive cycle, until the tendon can tolerate the load you’re trying to put through it. This commonly involves increasing the tendons tolerance load with strengthening exercises and also trying to reduce the load you put through to tendon, ie use of footwear, running technique advice, heel raise etc. Important to remember that if you reduce the load through the Achilles tendon, that load is transferred elsewhere, so we need to make sure the new area with increased load, can tolerate it.

Below is a diagram I use frequently in clinic to help describe ZOOS and the envelope function as I mentioned earlier, I cannot take the credit for this work, credit belongs to Dr Simon Spooner and Scott Dye. However is a useful tool to use, picture paints a 1000 words.

As you can see from the diagram above once injured, even going for a long walk may put excessive load through the Achilles tendon. You may have noticed on the diagram above the Achilles tendon and the ZOOS do not start in the same place, this is due to the fact that tendons need to be loaded, otherwise their capacity to tolerate load reduces. This brings me nicely into the 2nd myth;-

You need to rest and do no exercise for a few week, to cure your Achilles pain.

This may have not been helped by the term:-
Rest
Ice
Compression
Elevation

As we know complete rest will only prolong return to sport. We are now using a new term:-
Protect
Off
Load
Ice
Compression
Elevation

This may mean a rest from running, however other sports like swimming and cycling may still be ok, as this protects the tendon was excessive load, whilst allowing you to still exercise.

If we look at tendinopathy as a whole rather than just focusing on the Achilles tendinopathy, (Cook and Purdam 2009) have described tendinopathy as a 3 stage continuum:-

• Reactive tendinopathy – It is usually a reversible stage and this is where misnomer of information is thought to be, however we know that whilst there is an swelling present there is no inflammatory markers, the tendon structure tends remain the same.
• Tendon dysrepair – This follows the reactive phase when excessive load is still been applied, this is when we start to see the structural change to the tendon.
• Degenerative tendinopathy – This is a response due to chronic overloading, the tendon has undergone multiple changes and its capacity to tolerate load is reduced. Attending can appear thickened. This is most common within the older runner.

It is important to have an understanding of the continuum as this helps guide treatment, as treating the stage of the continuum incorrectly may actually increase pain. Many of you may have heard of the Alfredsson eccentric heel drop protocol, if you to complete this in the early reactive stage, this may actually increase the pain, however would be more helpful in the degenerative stage, hopefully this highlights the importance of understanding the different stages of the continuum.

Okay, my Achilles is hurting how may it be treated? Luckily (Cook and Purdam 2012) have offered some advice, tendinopathy management into 2 stages, though before moving onto the 2 stages, it is always worth looking for training errors yourself, this is where FitBit and Garmins are very helpful or even good old pen and paper to keep a log, you may notice a training error, that you did not realise was an error until examined the data.

Back to the 2 stages.
1. Reactive/ early disrepair – Isometrics
Key part of this stage is reducing the tensile and even more importantly compressive loads through the Achilles tendon (tendons do not tend to like compressive loading)

A = Compressive load B = Tensile load
Image modified from https://en.wikipedia.org/wiki/File:Compressive_tensile_shear_loading.jpg

Normally insertional Achilles tendinopathy are of a compressive nature, however it is important to remember that the midportion Achilles tendinopathy may also contain compressive and tensile elements.

To help reduce tendon pain, there is mounting evidence that doing isometric exercises in mid-range is helpful. Isometric means that the joint angle muscle length is not changed during loading, to the way to achieve this with the Achilles at mid range would be to stand on the edge of a step making sure the heel does not raise or drop.

• Hold 45-60 Seconds
• 4-5 sets
• Repeat 3 times a day

If irritable reduce the number of sets and time held for, or start with both heels off the edge of the step (Cook and Purdam 2013)

Also with this early stage, the use of NSAIDS ie Ibuprofen can be helpful, if taken correctly, often people do not take the drugs correctly, ie taking one just when the pain is present, the drugs need to taken for a certain length of time to have the desired effect, HOWEVER before you start taking drugs please consult with your GP or Pharmacist as NSAIDs can have some nasty side effects and cannot be taken by certain people. Though there is some evidence to suggest the use of NSAIDs negatively effect tendon healing, especially as the majority of tendinopathy I see in clinic is acute on chronic, meaning there has been a previous injury and this is a flare up. Personally, I don’t use NSAIDs.

2. Late dysrepair/ degenerative – Strength
This is where new evidence is coming through, with the jury still out on what is best. Instead of isometric exercises we are looking at isotonic exercises, which means generating force to change the length of the muscle, this can be concentric (shortening) and eccentric ( lengthening). In relation to the Achilles a heel raise is concentric and a heel drop is eccentric.

As midportion Achilles tendinopathy is more common, lets have a chat about this. The options we are looking at are eccentric loading, a mix of eccentric and concentric and heavy slow loading (heavy weights in the gym), the evidence is still coming out on this.

Tom Goom aka the running physio (http://www.running-physio.com) has put the current methods and evidence in a nice table and he kindly has let me use the table for this blog. It is worth noting that the evidence for Heavy slow Resistance exercise is for Patella tendinopathy, there are no equivalent Achilles studies yet, that I am aware of. On a side note, any one reading this who treats runners, needs to get on his running repairs course, it is a very good weekends teaching.

Permission to use from Tom Goom – http://www.running-physio.com/

A recent systematic review by Peter Malliaras and collegaues in 2013, confimred the use combined eccentric and connentirc laoding, over just eccentric.
Even though mid portion Achilles injuries are more common than insertional, I think it is important to re cap that insertional injuries are mainly compressive, so doing a heel drop will increase the compressive force, normally with insertional Achilles tendinopthy we do not use an eccentric loading.

Whilst on the subject of strength training, I believe that soleus is often overlooked in the management of Achilles tendinopathy, considering it takes nearly 8 times body weight in every step when your running, which is far greater than the other muscle in the area I think that a strong soleus is key into helping reduce and within the treatment of Achilles injuries. Some research has been done in this area by Seth O’Neill physiotherapist Leicestershire his currently a middle of his PhD, we are thinking that the pain free runner should be able to lift 1-1.5 times body weight through the soleus muscle.

It is important that during the management of the Achilles tendinopathy that the load is gradually increased, there is this rule of 10% increase every week to help avoid repetitive overloading this is a useful tool, however it is not a written in stone rule as 10% at the beginning would mean very little load increase, however 10% increase at the end of the training programme is a large increase in load, increasing your risk of re-injury. This is where running coaches are helpful, in the return to running.

Often in the early stages walk-run programmes are used, when getting you back running.
Whilst certain elements of strength training requires the use the gym and weights, there are things that you can use at home. Let’s look at doing heel raises for calf strengthening.

• Once you can manage 30 single leg heel raises on the flat
• Progress to off the edge of a step.
• Then progress by getting a couple of bags life and filling them with a 2 L bottle of water in each bag and then increasing gradually by adding more water over time, the main importance here is Progression and have the ability to monitor progression, as if you are progressing your more likely to keep up with the exercise program.

I have made a couple of videos of this with the running foundation, click here

As I mentioned earlier, my advice is always, seek professional help, get a diagnosis, get the correct treatment.

I’ve also just launched my new website www.nksportspodiatry.co.uk I shall be issuing monthly newsletters and there is a free download available on different lacing techniques your trainers, feel free to go have a look and download the advice sheet.

As always I am happy to discuss any elements of this blog and looking for ideas for my next one.

Happy running.

References

Alfredson, H., Pietila, T., Jonsson, P., & Lorentzon, R. (1998). Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis. Am J Sports Med, 26(3), 360-366.
Cook, J. L., & Purdam, C. R. (2009). Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. Br J Sports Med, 43(6), 409-416. doi: 10.1136/bjsm.2008.051193
Cook, J. L., & Purdam, C. R. (2013). The challenge of managing tendinopathy in competing athletes. Br J Sports Med. doi: 10.1136/bjsports-2012-092078
Dye, S. F. (2005). The pathophysiology of patellofemoral pain: a tissue homeostasis perspective. Clin Orthop Relat Res(436), 100-110.
Jonsson, P., Alfredson, H., Sunding, K., Fahlstrom, M., & Cook, J. (2008). New regimen for eccentric calf-muscle training in patients with chronic insertional Achilles tendinopathy: results of a pilot study. Br J Sports Med, 42(9), 746-749. doi: 10.1136/bjsm.2007.039545
Kongsgaard, M., Kovanen, V., Aagaard, P., Doessing, S., Hansen, P., Laursen, A. H., . . . Magnusson, S. P. (2009). Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy. Scand J Med Sci Sports, 19(6), 790-802. doi: 10.1111/j.1600-0838.2009.00949.x
Kongsgaard, M., Qvortrup, K., Larsen, J., Aagaard, P., Doessing, S., Hansen, P., . . . Magnusson, S. P. (2010). Fibril morphology and tendon mechanical properties in patellar tendinopathy: effects of heavy slow resistance training. Am J Sports Med, 38(4), 749-756. doi: 10.1177/0363546509350915
Malliaras, P., Barton, C. J., Reeves, N. D., & Langberg, H. (2013). Achilles and patellar tendinopathy loading programmes : a systematic review comparing clinical outcomes and identifying potential mechanisms for effectiveness. Sports Med, 43(4), 267-286. doi: 10.1007/s40279-013-0019-z
Silbernagel, K. G., Thomee, R., Eriksson, B. I., & Karlsson, J. (2007). Continued sports activity, using a pain-monitoring model, during rehabilitation in patients with Achilles tendinopathy: a randomized controlled study. Am J Sports Med, 35(6), 897-906. doi: 10.1177/0363546506298279