Achilles Tendinitis in Runners

by: Elena Jara, MS PT (30mile/wk runner based on own experience)

Have you ever experienced pain at your heel while engaging in vigorous activities?  Or when rising on your tiptoes? Or pain with initial morning activity ?  Is the pain sharp or burning and may interfere with activities of daily living?  If you rest, does the pain subside?  If you answered yes to these questions, chances are you have or previously had the condition known as Achilles tendinitis.

The Achilles tendon is the largest tendon in the body.  It begins where the muscle belly of the gastrocnemius (calf muscle) ends and attaches to the posterior (back) surface of the calcaneus on the heel bone.  The tendon is approximately 15 cm in length and has the shape of a ribbon. Most Achilles tendon injuries affect the tendon  2 to 6 cm above the heel bone where the tendon is the thinnest and blood supply is low.

A chronic, degenerative process, Achilles tendinitis is an overuse injury and is a result of repetitive, accumulative impact loading to the tendon.  It is a common injury treated at sports medicine clinics.  Reported estimates of the prevalance of Achilles tendinitis are 11% runners, 9% dancers, 5% gymnasts, 2% tennis players,  and <1% football players.  The mean age is 24-30. 

Intrinsic contributing factors of the condition include decreased vascularity of the tendon, aging, degeneration of the tendon, poor gastrocnemius-soleus flexibility, and anatomic deviations such as heel-leg or heel-forefoot malalignment.  Studies have shown that individuals with a genetic varus position of the heel or supination of the forefoot experience functional overpronation of the foot during running.  It has been concluded that this mechanical deformation may cause a whipping action in the Achilles tendon and increased friction between the tendon and peri-tendinous tissue.

Extrinsic factors that predispose an athlete to tendinitis include a sudden increase in training intensity, interval training, change of surface (grass to pavement), and inappropriate or worn-out footwear.

• Pain and tenderness along the tendon. 

• Pain aggravated by activity and relieved by resting.  

• Pain when performing a single heel raise.  

• In the early stages, pain with prolonged running.  

• In the early stages, pain subsides rapidly with rest, but may be exacerbated by climbing stairs.

• In the subacute stage, pain present at the start of run and worsens with sprinting.

• In the advanced stages, if there is a tendonosis (degeneration of the tendon) or a partial rupture of the tendon, inability to run and pain at rest.  

• Weakness and intermittent swelling.  
  
  Several experts think that the presence and severity of morning stiffness is a good standard by which to evaluate the seriousness of the condition. 

Physical findings include: 

• swelling and warmth to the touch

• tendon thickening  

• calf atrophy and weakness 

• tendon nodularity may be present in chronic cases

• crepitus is rare.  

Achilles tendinitis is always treated conservatively first and may continue for 4-6 months.  If this treatment fails to relieve symptoms, surgery may be necessary.  

Treatment may include:

• rest or a decrease in runners weekly mileage

• use of a 1/4" to 3/8"  heel lifts to decrease tension on the tendon

• oral NSAIDS

• use of an orthotic to correct excessive pronation

• physical therapy including ultrasound and stretching exercises. 
  
  Total rest is usually not required, but hill work and interval training should be avoided.  A form of modified rest is sometimes recommended, where activities such as biking and swimming are allowed, but no running until 7-10 days after the symptoms have subsided.  If symptoms are severe, initial treatment may include 1-2 weeks of immobilization and crutch ambulation, in addition to NSAIDS, ice and heel cord stretching. 

Stretching exercises has proven to be key in non-operative management of tendinitis.  It is common to find a loss of dorsiflexion (ability to pull toes up) of the foot in individuals with Achilles tendinitis, which adds to the symptoms.  It is important to keep the calf as flexible as possible.  The gastroc and soleus stretch should be performed to keep the calf from stiffening.  Stretching should be slow and static, never bounce.

Be aware that steroid injections are not recommended and may in fact increase the risk of tendon rupture.

Surgery is not usually recommended.  Studies have shown that conservative treatment has extremely positive results and most runners return to activity symptom-free.   

It is important to understand that the athlete will not remain symptom-free unless they understand the extrinsic factors that caused the injury and take preventative measures to avoid tendinitis that include:

• warming the Achilles tendon before running

• stretching to prevent contractures and loss of passive dorsiflexion 

• applying ice for 10-15 minutes after running

• wearing proper shoes and monitoring condition of shoe wear particularly if overpronation or poor hindfoot support is an issue