Achilles Tendinopathy and Associated Injuries
Achilles tendon injuries are a common sight in most sports injury practices. The Achilles tendon is the largest tendon in the body, connecting the powerful calf muscles to the heel bone to give propulsion for running. It also acts as a powerful absorber of the force generated by gravity when the foot strikes the ground in running, walking, jumping and hopping.
In our health education series, Mark Adshead, Managing Director at Physio2go Ltd, joins forces with Mr David Gordon, Consultant Orthopaedic Foot and Ankle Surgeon at the Spire Hospital Harpenden and Honorary Senior Lecturer at University College London. Together they look at the causes, investigations, and management of this potentially troublesome collection of injuries.
What is it?
The Achilles tendon connects the large muscles of the calf (gastrocnemius, soleus and plantaris) to the heel bone (calcaneum). The gastrocnemius and plantaris muscles are attached to the bone above the knee joint whereas the soleus is attached to the bone below the knee joint. This distinguishes between them in relation to how they perform functionally in that the gastrocnemius and plantaris span two joints (knee and ankle) and are more involved in rapid contractions producing lots of spring and propulsion such as running, jumping and hopping. The soleus muscle only spans the ankle joint as it is attached to the bone in the lower leg and is a more slowly contracting muscle which is suited to stamina situations such as jogging, long distance walking etc.
How can they be injured?
Although the Achilles tendon can be injured by a direct blow, such as a kick when playing football, it is much more commonly injured by repetitive strain. This can be as a result of direct pressure, such as a high heel tab from footwear constantly pressing into the tendon on each step. Most often though it is as a result of micro trauma due to ‘overuse’ during repetitive foot strike sports such as running (football, rugby, hockey etc.), jogging, and long distance walking and hiking. There may be misalignment of the tendon due to foot or heel malposition referred to as over pronation. This can be seen when standing barefoot, looking from behind, as the instep (medial part) is lower to the ground. When viewing the Achilles tendon from behind a curve can be seen which is convex on the inside (medial) and concave on the outside (lateral) aspects of the tendon thus causing excess strain and potential micro trauma. It may be this reason that the inside (medial) aspect of the tendon is more tender and swollen than the outside (lateral) aspect when assessed by the physiotherapist. Usually people with Achilles tendinopathy have ankle and foot alignment within a normal range.
As the micro trauma builds up with the repetitive nature of the injury mechanism it is often the case that we see people who initially report that they could “run through” the pain but that as time goes on they have to curtail the time and distance they can run before it is too painful to continue. All too often we see people training for the London Marathon in late March and early April where they have struggled since January where they were running 8 or 10 miles and noticed an Achilles pain, but then two months later they can hardly run 5 miles before they have to stop in agony. Unfortunately for most it is too late to treat them effectively and get them to the start line in late April, where a trip to get help in January could have saved the day.
A more dramatic onset is seen when the Achilles tendon snaps. This happens without warning, often something as trivial as stepping off a kerb, and is described by patients as if they have been shot in the back of the lower leg accompanied by a tearing or snapping sensation. Initially this can be extremely painful, but once the tendon has snapped can be relatively pain free as there is no tension remaining across the injury site. However when trying to walk there is an inability to fully control the foot which often has a limp appearance which one patient described “as if he had a piece of wet fish attached to his ankle”. In contrast, if the calf muscle (usually the medial head of gastrocnemius) has suddenly partially ruptured, this is much more painful as there is considerable tension remaining within the damaged area of muscle and the typical gait is of walking with the foot on tiptoe but not being able to put much weight through it.
In these more dramatic presentations the common factor is that the Achilles tendon/calf muscle complex is being asked to rapidly contract to absorb the whole body weight being placed through the front part of the foot in varying degrees of a tiptoe posture. It is referred to as eccentric muscle work and this forms the basis of the muscle training required for a return to full fitness.
What is the difference between concentric and eccentric muscle work?
In simple terms most of us think of a muscle shortening when it contracts thus causing a movement of a joint in the body. At school most of us can remember being taught that the biceps muscle on the front of the arm contracts (shortens) causing the elbow to bend and that the triceps muscle on the back of the arm contracts to straighten the elbow. These are examples of concentric muscle work. Eccentric muscle work on the other hand is where a muscle is being asked to contract but whilst its length is increasing from a shorter position to a longer position. If you stand up and bend your arm you can feel the biceps muscle contract and the triceps muscle is floppy. If you remain standing and straighten your arm you can feel the biceps muscle is still in a state of contraction as the elbow straightens and the triceps remains floppy.
The human body however has to work in a world where our movement is hugely influenced by the force of gravity. As a result, muscles are often asked to contract to control the weight of the body being pulled by gravity. This is where eccentric muscle work is most commonly seen. A good example is going downstairs where you will find you always put your toes onto the step below and then gradually lower your weight down onto your foot, thus asking your calf muscles to contract as the heel drops onto the step. The Achilles tendon has to be able to cope with frequent eccentric loading therefore eccentric muscle work forms a large element of the rehabilitation programme (see exercises below)
Physiotherapy treatment for Achilles tendinopathy and calf muscle injuries
The first thing that has to be established is to identify and eliminate the cause of the injury. As with all injuries a full assessment of the injury will be carried out and a treatment plan discussed and established between the physiotherapist and the patient.
If there is a structural problem within the body, such as overpronation, then this can often be easily overcome in the purchase of the correct footwear. There are many sports shops specialising in gait analysis who will use a variety of methods from looking at static foot posture, treadmill running, video analysis using an i-pad or similar, to just watching you run along the pavement outside the shop. They will then advise on your running style and supply the correct shoe for you. Where this proves insufficient, a shoe may require additional support for the foot and this is often where orthotic insoles are advised. It is worth pointing out, there is weak scientific evidence to support the use of sports footwear or orthotics which aim to correct foot alignment (like over pronation), in preventing or treating injuries. Be cautious on what you are sold!
In many cases where an orthotic is required this can be a simple inexpensive “off the shelf” device. It is only in a relatively small number of cases that a custom made device is required and this is best provided by an experienced podiatrist or other medical professional with lots of experience in this field. I would expect any good sports footwear retailer to make sure that there is no impingement of the Achilles tendon by a heel tab.
Where there has been micro trauma, the Achilles tendon will probably be swollen and it is likely that this will be tackled using such treatments as ultrasound, deep transverse frictional massage, cryotherapy (ice treatment) and soft tissue stretching exercises incorporating eccentric muscle work.
Achilles eccentric stretching exercise
Hold this position for approximately 5 seconds. You have completed one repetition.
Repeat this until you have completed 5 repetitions, then perform a further 5 repetitions with the knee of the affected leg slightly bent. You have now completed one “set” of exercises.
It is important to note that you should stop the exercises as soon as you feel any increase in pain. You can now proceed to use this as a basis for your rehabilitation as follows:
Day 1-2 – 1 set of 10 repetitions (5 x knee straight + 5 x knee bent)
Day 3-4 – 2 set of 10 repetitions. 1 minute rest between sets
Day 5-6 – 3 set of 10 repetitions. 1 minute rest between sets
Day 7 – Continue to increase the sets until you reach the point of fatigue within the calf muscles. 1 minute rest between sets.
Once you have reached this level the exercises should only be performed on alternate days
WARNING: This is not a replacement for a personal exercise programme, designed and supervised by your medical practitioner. If you experience any increased pain or adverse sensation then see your Doctor or Physiotherapist for specific assessment, treatment and advice in relation to your specific problem.
Further investigation and treatment
In the small percentage of cases where the injury fails to resolve fully with conservative treatment then onward referral to an Orthopaedic Foot and Ankle Consultant is advised. Following a thorough history taking and examination, further tests such as a dynamic diagnostic ultrasound examination or even an MRI scan may be required. This is to assess the degree and location of tendon involvement, to rule out any tears and assess neovascularity (new blood vessel formation thought to be implicated in pain).
Extracorporeal Shockwave Therapy (ESWT)
Anti-inflammatory medications such as ibuprofen or naproxen tend not to be helpful unless there is inflammation, which does not occur in overuse tendinopathy. The scientifically proven treatment for Achilles tendinopathy is extracorporeal shockwave therapy Shockwave Therapy. This five minute treatment is administered by the surgeon in clinic with the patient awake. Three sessions are given a week apart and there are no restrictions on activity following treatment. ESWT has no side effects but there is discomfort during the 5 minutes of the actual treatment. Shockwave Therapy in conjunction with an eccentric stretching programme are the two scientifically proven treatments for Achilles tendinopathy.
Due to the low metabolic activity of the Achilles, treatments take time to work, much to the frustration of the athlete, especially when they have an event goal. It may be 3 months before a significant resolution of symptoms occur. If shockwave and eccentric stretches are not effective, then next step are ultra sound guided injection. A High Volume Injection of saline and steroid and injected under the lining of the Achilles tendon. This ‘strips’ the tendon of the painful neovascularity and has been shown to be good for pain relief.
In the very few cases where the tendon fails to respond, or when certain pathologies are diagnosed, then there are a few surgical procedures which can be performed but only where there is specific medical evidence to support their use. It is unusual to need surgery for Achilles problems. Mr David Gordon however uses Minimally Invasive Techniques where possible, utilising very small incisions to treat certain Achilles problems. As with any surgery there are always risks which will be fully discussed with your Consultant before the decision to proceed is made.
Returning to sport
It is important to graduate any return from injury to sport again. Your physiotherapist will assess both the severity of your injury and the physical needs required by your tendon to return to your sport. The most common factors are strength, stamina, agility, speed, power and proprioception. The timescale for recovery will depend upon how much work needs to be performed to restore these particular attributes for return to your specific sporting activity. Your physiotherapist (in conjunction with your sports coach if you have one) will help devise a series of sports specific exercises to achieve your goals.
Mark Adshead MCSP
Tel: 01727 850925
Mr David Gordon MBChB, MRCS, MD, FRCS (Tr & Orth)
Consultant Orthopaedic Foot and Ankle Surgeon
Tel: 0207 993 2373