PT on the Net Research

Achilles Tendinopathy

Coauthored by Cassie Lyall

Tendinopathies can come under two different blanket terms: Tendonitis, which has previously been defined as “inflammation of the tendon sheath” due to an overuse action. A second term, Tendinosis, is also known as a degenerative tendinopathy. This occurs when microscopic tears start to form at the tendon sheath due to a variety of different  factors. Since tendons have such a minuscule blood supply the repairing process is either delayed or limited, thus causing degeneration of the tendon to occur.1

Achilles Tendonitis is often the term used for inflammation of the tendon sheath in the Achilles’ tendon located at the heel of the foot. When this tendon is overused, as is commonly seen in runners, it becomes inflamed, causing pain at the base of the heel. Achilles’ tendons can reach forces up to 12.5-17 times the bodyweight during running;2 such a force can cause injury to occur. Simply, it is the strongest tendon in the body.

There are two main types of Achilles Tendinopathies: Midportion Achilles Tendinopathy and Insertional Achilles Tendinopathy. It is vital to differentiate the two different types, as they differ in response to treatment.3 Midportion Achilles Tendinopathy consists of inflammation and weakness to the tendon approximately 2-6 centimeters above the calcaneus,4 whereas Insertional Achilles Tendinopathy occurs directly on the calcaneus where the tendon attaches to the bone.

Signs and Symptoms

Along with the main symptoms, such as pain and tenderness on the Achilles’ tendon and thickening of the tendon in comparison with the non-symptomatic tendon, some signs to look for would be ‘start-up’ pain. Start-up pain is the pain that occurs in the tendon at the beginning of any exercise, which settles when the athlete or client is warmed up.5 Other signs to watch for are stiffness of the Achilles’ tendon, particularly following rest and intermittent pain that comes on with exercise and activity.6 With these signs there will also be a decrease in dorsiflexion range of motion7 and weakness and a reproduction of the pain with plantarflexion.8 The calf muscle belly may also be taut on palpation.

Injury Mechanisms

An Achilles Tendinopathy is a chronic injury that comes on gradually and can be caused by one or more different mechanisms. Achilles Tendinopathies can be brought on by inappropriate training regimes, such as quickly increasing running distance, speed or gradient or the decrease in recovery time between training sessions. There can be extrinsic factors such as change in running surface, change in footwear or inappropriate footwear. Finally, this Tendinopathy can be caused by biomechanical faults such as excessive pronation,9 calf weakness, poor muscle flexibility (tight calf muscles), poor range of motion (restricted dorsiflexion) or genetic predisposition.


The treatment protocol of this injury with a physiotherapist or sports therapist can consist of massage therapy to help loosen the calf muscle, transverse frictions10 to decrease the pain on the Achilles’ tendon and electrotherapy modalities, such as therapeutic ultrasound, to help speed up the recovery process and decrease any inflammation. Acupuncture has also been seen to have a positive effect on the recovery of this Tendinopathy as it helps bring blood to the injury site to help speed up the recovery process. Although, due to the hypovascularity to the area that exists within the tendon, healing and recovery time can be slow.

There is much debate as to the proper rehabilitation of an Achilles Tendinopathy and whether rehabilitation regimes should focus on strengthening or stretching. Current research has found that strengthening eccentrically while incorporating stretching after is the best practice. Eccentric training or loading refers to loading the muscles while it is in a lengthened position11 which has shown to be very beneficial to the recovery of the Achilles’ tendon. Brukner and Khan (2007) and Prentice (2004) have shown that eccentric exercises in the form of heel drops have the largest benefit in the rehabilitation of the tendon. Alfredson et al.12 found that incorporating two different types of heel drop were more beneficial to the recovery of the tendon. The first protocol consists of dropping the heel while keeping the knee straight, which focuses on the gastrocnemius muscle; the second protocol consists of a similar heel drop while bending the knee which incorporates the soleus muscle, both of which strengthen the Achilles’ tendon. Stretching is also vital in the rehabilitation of the tendon, as it helps keep the tendon flexible.

Sample eccentric exercise program:


There are two different types of Achilles Tendinopathies: Midportion and Insertional Tendinopathies. It is a very prevalent injury in running athletes with an incident rate of 24%. The main signs and symptoms are stiffness of the tendon and localised pain along the tendon; pain typically decreases with the start of easy activity. Massage therapy, therapeutic ultrasound and acupuncture have been shown to be beneficial. Rehabilitation consists of eccentric strengthening of the tendon as well as stretching.


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