Full guide to Achilles tendon injuries

Achilles Tendonitis: symptoms, prevention techniques and treatments

achilles tendon injury

 What is the Achilles tendon?

The Achilles tendon is situated above the heel and forms the lower part of the calf muscles. It is a continuation of the two calf muscles, the gastrocnemius and soleus muscles, and it attaches to the heel bone.
It is the strongest tendon in the human body and must withstand great forces. Its function is to transmit the force produced by the calf muscles to lift the heel and produce the push off during walking, running and jumping. The Achilles can produce force of up to seven times body weight. This shows just how much force it has to withstand during sporting activities, such as sprinting, jumping and turning.

Understanding terms for Achilles tendon injury

Achilles tendinopathy is a common sports injury. It’s caused most frequently by overuse. You might be more familiar with the term ‘Achilles tendonitis’. However, in the absence of inflammation, tendinopathy is the more appropriate term.
Until medical examination determines if there is Achilles degeneration (tendonosis) or inflammation (tendonitis) the condition is referred to as tendinopathy.
Achilles tendinopathy is characterised by degeneration (tendonosis) of the tendon, often without an inflammatory response. The degeneration means that the tendon does not have the usual tensile strength and may be liable to rupture during continued sporting activity. However, before you get alarmed, this is very unlikely.


Symptoms usually come on gradually. Depending on the severity of the injury, they can include:

  • Achilles pain, which increases with specific activity, with local tenderness to touch.
  • A sensation that the tendon is grating or cracking when moved.
  • Swelling, heat or redness around the area.
  • The affected tendon area may appear thicker in comparison to the unaffected side.
  • There may be weakness when trying to push up on to the toes.
  • The tendon can feel very stiff first thing in the morning (care should be taken when getting out of bed and when making the first few steps around the house).
  • A distinct gap in the line of the tendon (partial tear).

The causes of Achilles tendon injuries

Overuse and changes in training
Inflammation/strain of the tendon is usually caused by overuse – for example, frequent jumping in volleyball, netball or basketball. It is often also caused by a sudden increase in certain types of training, such as hill sprinting or track running, particularly when running in spikes.

Getting older
Tendinopathy can also be associated with ageing. Our ability to regenerate damaged tissue decreases as we age and the quality of the tendon deteriorates. However, the better news is that sensible training can actually strengthen all our soft tissue (tendons, ligaments and muscle).

Tight calf muscles
Tightness in the calf muscles will demand greater flexibility of the tendon, which inevitably results in overuse and injury. Biomechanically, the tightness can reduce the range of dorsiflexion (toe up position) in the ankle, which increases the amount and duration of pronation. This problem is known as overpronation.* This reduces the ability of the foot to become a rigid lever at push off and places more lateral and linear forces through the tendon. This imbalance can translate into altered rotation of the tibia (shin bone) at the knee joint and, in turn, produce compensatory rotation at the hip joint with subsequent injuries to the shin, knee and hip.

*Pronation is part of the natural movement of the subtalar joint in the foot. It allows ‘eversion’ (turning the sole outwards), dorsiflexion and abduction (pointing the toes out to the side). Pronation is a normal part of the gait cycle, when walking and running, and it helps to provide shock absorption in the foot. When pronation is excessive, the foot has a tendency to roll inward more than normally acceptable. One sign of overpronation is greater wear on the inside of your running shoes than on the midsole.

Lack of ankle stability
Lack of stability around the ankle joint can also be a contributory factor, as recurrent ankle sprains appear to be associated with a high incidence of Achilles tendonopathy.

Wearing the ‘wrong’ shoes
Wearing shoes that don’t fit or support the foot properly can be a major contributing cause of Achilles tendon injury.


A detailed history, and examination by an appropriately qualified health professional, will allow a diagnosis to be made. An ultrasound or MRI scan can confirm the diagnosis.
Other causes of symptoms in the area, such as those referred from the lumbar spine and local infection, should be excluded.


Good flexibility of the calf muscles plays an essential role in the prevention of Achilles tendon injuries.

It is also important to include balance and stability work as part of the training programme. This should include work for the deep-seated abdominal muscles and for the muscles that control the hip. This might at first appear odd, given the fact that the Achilles are a good distance from these areas, but developing strength and control in this area (core stability) can boost control at the knee and ankle joints.
Training errors should be avoided. The volume, intensity and frequency of training should be monitored carefully, and gradually progressed, particularly when introducing new modes of training to the programme. Abrupt changes in training load are the primary cause of Achilles tendinopathy.

It is important to maintain a personal training log, to monitor training changes, and to recognise, and hopefully prevent, injury. And – if you are unfortunate enough to sustain an injury – to recognise where mistakes were made and prevent further errors.

Footwear and training advice
I have found that, when track athletes (particularly sprinters), run over-distance repetitions (for example, 300m) as part of their training, the Achilles is subject to great forces, as the athlete tires and their heel drops further during each ground contact. This can be counteracted by purchasing a pair of middle-distance-type spike shoes that have a protective heel wedge. This reduces the strain on the tendon, as the shoe’s heel offers greater protection, and is not subject to overstretching when fatigue is present. I also advocate that any running below 90% of maximum speed is performed in trainers and preferably on a stable grass surface.

Similar advice can be given to field sport players, to ensure that their footwear has sufficient heel support, both at the base of the heel to cushion impact and around the ankle to prevent excessive pronation.  It is also common to see field sport players, for example, rugby or football players, go straight into wearing their boots at the onset of pre-season training. This is risky, as the pitches are inevitably hard at this time of the year (July/August). Also they will probably not have worn their boots since April/May. And – particularly with amateur sportspeople – a regime of stretching and conditioning has probably been neglected during the summer break.

This is a recipe for injury. I would therefore advise that specific football/rugby trainers be worn, until the body adapts to the training, and then more specific footwear should be gradually introduced.

Very often sports people wait until their sports footwear (trainers/boots/spike) are well beyond the state at which they provide adequate protection and support before replacing them. Then, after an injury has occurred, they are advised by a physiotherapist and/or coach to buy a new pair. Trust me, it is cheaper to buy sports footwear regularly and stay healthy, than to pay for physiotherapy treatment (and buy the necessary footwear).


Ice therapy is an effective form of pain relief. Observe the PRICE protocol:


This can relieve the symptoms of a painful swollen Achilles tendon. Using ice packs for a period of 20 minutes every two hours can help with the swelling and pain, but pain relieving medication may also be required.

The use of anti-inflammatory medication is not appropriate. Using ice packs can relieve pain, but the key to recovery is in trying to elicit healing without overloading the tendon.

It may be necessary, in severe cases, for players to rest from high-impact activities for up to three months. This is because the collagen tissue, which the body produces to repair the damaged Achilles tendon tissue, can take three months to lay down.

Non-impact training, such as pool work, can maintain fitness during this period, and other body parts can be exercised with weights or other exercises. A physiotherapist may gently mobilise the soft tissue by providing controlled stress to help the tendon adapt and gain tensile strength.

Published research has suggested that recovery is promoted by using a very gradually progressed strengthening programme for the Achilles tendon and calf muscles under the supervision of a physiotherapist. This strengthening programme uses eccentric muscle work, which means that the muscle is lengthening while contracting. Maximum tension is generated in the muscle and tendon during eccentric contractions.


It is important that an appropriately qualified therapist looks at the players’/athletes’ overall body alignment to detect if the injury has been caused by a biomechanical problem. Over pronation can place excessive strain on the Achilles and lead to Achilles tendinopathy. An orthotic insert may be required but, in many cases, biomechanical problems are caused by stiffness in the joints. The therapist can mobilise them, which, if normal range of movement is attained and maintained, can often eradicate the problem.


  • Consult a sports injury expert.
  • Apply ice packs.
  • Wear an Achilles strap to relieve symptoms.
  • Wear a heel insert to relieve heel pain.


Pathological change in the tendon can manifest as tendon swelling or as nodules. A correct clinical diagnosis can often be established by clinical examination, especially if the tendon shows signs of swelling. If this is not clear, then ultrasonography or an MRI scan may reveal the problem within the tendon. It is essential to seek a professional with the clinical acumen to correlate clinical and imaging examinations.

The clinical examination should ensure that there is no acute rupture of the tendon and, after demonstrating that the tendon is intact, the examiner should aim to induce tendon pain by guiding the patient through various tendon-loading activities.

Quite often, simple single-leg heel raises will be enough to cause pain; however, it may be necessary for the examiner to ask the patient to hop on the spot or forward to produce a pain response.

A competent examiner will check to exclude other diagnoses, such as a problem with the soleus (the smaller calf muscle) or injury to the plantar flexor tendons (those that assist the toe-down movement of the foot), which can cause pain in and around the Achilles tendon.


Many professionals recommend conservative (ie, non-surgical) treatment as the best practice for Achilles tendonosis. This follows the identification of causal factors, such as new training shoes, a change of training regime or excessive running on roads with a severe camber, etc. A symptom-related approach to treatment may include:

REST – Either complete, or modification of activity.

ICE – An ice pack wrapped in a damp towel applied to the area for up to 20 minutes can help to reduce inflammation and ease pain. It is advised to prepare the skin by applying some oil and to regularly check the skin so as to minimise the risk of an ice burn.

MEDICATION – A GP or pharmacist might suggest taking an anti-inflammatory or an analgesic such as paracetamol or ibuprofen. Recent studies have shown that glycerol trinitrate patches, usually used in the management of angina, are helpful in the management of chronic tendinopathies. Corticosteroid injections should be administered with great caution as they can result in tendon rupture.

ORTHOTIC TREATMENT –A temporary heel lift will reduce tension on the Achilles tendon. A change of footwear should be considered if the athlete’s shoes contributed to the onset of symptoms.

ACTIVITY – Stretching and strength training, eg eccentric/concentric work (of which more later).

A physiotherapist might apply soft-tissue mobilisations (such as graded stretches) to the affected area, to assist the healing process and improve the quality of soft-tissue motion.

Strength training should commence with pain-free concentric contractions such as resisted plantar flexion (pressing the foot down towards the ground), using resistance band or heel raises, and progress to include eccentric muscle training (of which more later).

If conservative treatment fails, surgery may be an option. However, the good news is that in 75% of cases, conservative treatments work.


ECCENTRIC TRAINING (lowering of the heel)

Research carried out in 1984 (1) stressed the importance of eccentric training as part of the rehabilitation of tendon injuries. It was demonstrated that a six-week programme of progressive eccentric loading of the tendon was successful in alleviating Achilles tendon pain. During an eccentric contraction, the muscle elongates while under tension (whether this be the result of body weight or through added resistance), as it does during the lowering portion of a heel raise, when the muscle acts to decelerate or control the movement.

The above programme was subsequently incorporated into a 12-week programme of eccentric calf muscle training for painful mid-portion Achilles tendinopathy and scientifically evaluated by Hakan Alfredson et al (2, 3). Alfredson is a professor of sports medicine and an orthopaedic surgeon.

This training programme requires the patient to complete the programme despite pain in the tendon.

If and when the patient experiences no pain while carrying out the programme, the load should be increased until the exercises do cause pain – this sequence is then repeated.

It is reported that Alfredson’s programme is effective when other non-invasive conservative methods have failed (see list above). It is successful in 90% of patients with mid-tendon pain and pathology. Patients with Achilles pain at the tendon insertion do not respond as well to this programme; however, good results are nonetheless achieved in around 30% of those with this type of problem who complete the programme.


Other eccentric training programmes for the treatment of Achilles tendinopathy are reported to have been successful but they have not been subjected to the same rigorous evaluation as the Alfredson programme.

Results of surveys have shown that heel-raise (concentric) training programmes have not proved nearly as effective as heel-drop (eccentric) programmes.

heel-drop techniquePicture 1

Alfredson’s painful heel-drop protocol

Number of exercises: 3 x 15 repetitions

Frequency: 2 x a day, 7 days per week

Technique: There are two versions of the exercise: one is performed with the knee straight – see picture 1 (activating the largest calf muscle, the gastrocnemius) and the other with a bent knee (activating the soleus) – see picture 2.

Important – remember, each time the active (affected heel) is lowered, you should use the unaffected leg to raise the injured foot back up onto its toes prior to the next repetition.

Use your hands/arms to stabilise your body prior to and during each repetition of the exercise.

Picture 2

** In the photographs the athlete performs the exercises in both the straight knee and bent knee version. Note: the heel is in the lowered position in both photos and, out of view, the athlete is holding onto a training partner for stability.

1. Straight knee gastrocnemius drop – The patient begins with the heel raised and the knee fully extended (the leg is straight). He or she then lowers their heel so that the foot is parallel to the ground.

2. Bent knee soleus drop – The patient again adopts a position on the edge of a step, with their heel raised, but this time the knee of the active leg should be flexed at 45 degrees so that the soleus muscle is engaged. The patient then lowers their heel so that the foot is parallel to the ground.

Progression: Do the exercises until they become pain free, using body weight. Then add load, via a barbell or dumbbells, until they are painful again. Progressively add load up to 60kg.



Karen Storey, the co-author of this series of articles, is a qualified physiotherapist and has been a competitive sprinter for 20-plus years . During the summer track season of 2000 (mid-June), Karen suffered from quite severe Achilles tendon pain. Following a rich vein of early season form during which she improved both her 100m and 200m personal bests, Karen competed in a sprints triathlon competition – 100/200/400m in a single afternoon. The repeated efforts, performed on a quite ‘springy’ track, proved to be too much for Karen’s Achilles, and she felt pain the next morning when getting out of bed and putting her feet on the floor.

Experiencing pain on taking the first step of the day is common with people who suffer from Achilles tendonitis. Quite often, the pain lessens throughout the day as mobility improves. However, on this occasion the pain eased only slightly, with the result that Karen had to curtail her training and cancel competitions that had been scheduled for the coming weeks.

The plan had always been to compete in the Scottish National Championships in Glasgow at the end of August, at 400m (Karen’s favoured event). Build-up races had been scheduled but were now shelved, and Karen’s training schedule had to become a rehabilitation programme, with a view to either competing in Glasgow, or being fit enough to commence winter training in September with a clean bill of health.
Karen designed a programme of heel-drop exercises for herself, similar to those of Alfredson’s protocol. The first five days consisted of rest and ice treatment. She continued with the heel-drop protocol and by the tenth day was virtually free of pain.
Over the next 20 days, Karen was able to jog and perform basic sprint drills with limited range on grass.

Three weeks after the onset of the pain she was able to stride on grass, building from 60%; by week five she had progressed to 80% intensity, still running on grass.
A week prior to the Championships, Karen moved onto the track to perform a session of strides at 80%.

To reduce the strain on the Achilles, she used heel raises in her spiked shoes.
The only session of specific starts was performed five days before the competition (to allow any adverse reaction to the Achilles a chance to settle). We considered block starts to be the activity that would place the greatest demand on the Achilles tendon, so only three of these were performed at 400m race pace over 30m.

Thankfully, there was no major reaction and, three days prior to the competition, Karen performed a small number of 60m sprints on the track.
And the happy ending? Karen ran the 400m in the Scottish National Championships as planned, and achieved a personal best of 56.8sec – just six weeks after suffering from Achilles tendonitis.


Phil Gardiner is a UK level 4 track-and-field coach.

Karen Storey MCSP is a chartered physiotherapist, specialising in the treatment and rehabilitation of sports injuries. Karen is also an athlete with over 20 years’ competitive experience, including winning medals at area level at 400m.



  1. Curwin S, Stanish WD. Tendinitis: its aetiology and treatment. Lexington: Collamore Press 1984
  2. Alfredson H, Cook J. A treatment algorithm for managing Achilles tendinopathy: new treatment options. Sports Med 2007, 41, 211-216
  3. Alfredson H, Lorentzon R  Chronic Achilles tendinosis: recommendations for treatment and prevention. Sports Med 2000, 135-46
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