Tendon Injuries: Getting Back to Go

by G. John Mullen, DPT 2011 | mullen@myhousecallmd.com

With the Vancouver Winter Olympics in full swing, tendon injury is a hot topic on news channels across the globe.  Sports fans from every nation will be cheering on their favorite athletes and crossing their fingers for speedy recoveries from accidents Olympic Speed Skaterincurred during the intense competition in the coming weeks.  Shoulder pain, elbow pain, ankle pain?  These joints are common sources of pain for professional athletes and law-abiding citizens alike.  Whether you have golfer’s elbow, tennis elbow, speed skater’s knee, shoulder impingement, jumper’s knee, Achilles tendon pain, you are suffering from a “tendinopathy.”  Tendons, which connect muscles to bones, are composed of collagen.  Tendinitis is the most common term associated with tendinopathy. Tendinitis is the acute injury of a tendon and is typically associated with inflammation (note that “-itis” means inflammation). Tendinosis is a term used less commonly but refers to the process in which tendinitis becomes chronic (lasting greater than 3 weeks). To understand the disease of tendinopathy, it is essential to understand the design of a tendon, common causes, treatments for the different types of tendinopathies and what you can do to prevent these disorders.

Stat Fact: The prevalence of Achilles tendinosis has been estimated to be between 11% and 24% in runners, whereas the prevalence rate for patellar tendinosis in basketball and volleyball players has been recorded as high as 32% and 45%, respectively4.  That’s a lot of tendon inflammation.

Tendon Architecture

As we mentioned earlier, the tendon is primarily composed of collagen, more specifically type I collagen (there are 29 different types of collagen in the body but 4 main types make up 90% of our collagen).  Tendon tissue has a poor blood supply (only 1/3 Achilles Tendonof the blood supply that muscles have) which means that it takes tendons notably longer than muscles to heal.  Following an acute injury, the tendon strained becomes inflamed (filled with cells trying to repair the tissue).  After chronic use of the tendon, type III collagen becomes predominant.  This change in collagen will make the tendon larger due to increased collagen rather than from inflammation.   Along with the increase in collagen comes an increase in water in the tendon as well.  These two changes make the tendon thicker which you notice as increased stiffness.  At the same time, the tendon becomes more compliant leading to an increased rate of tendon strain after a chronic tendon injury.  Cadaveric studies suggest after a chronic tendon injury, the strain increases causing a decrease in stiffness and strength.  Strain is “the amount of displacement with an external load placed on the object” or, in the cadaveric study, “the amount of displacement increased after injury.”  Essentially, it means the amount of laxity (“looseness”) in the tendon after injury.

Common Causes

The majority of tendinopathies are due to overuse and are caused by such activities as:

  • Rapid increase in usage (New Year resolutions…)

  • Not warming up properly

  • Changes in footwear (for lower extremity tendinopathies)

  • Weak surrounding muscles

  • Improper muscle length or flexibility

Stat Fact: Achilles tendinopathy is a common overuse injury, accounting for 11% of all running injuries2.

Tendinitis Treatment

Tendinitis is an acute tendon injury associated with inflammation. Tendinitis is caused by an accident that causes damage to the tendon or chronic use leading to tendon irritation.  The length of this inflammation is variable, therefore the term tendinopathy is used to classify all the tendon injuries Icing a Knee Injury(you know doctors don’t like to put timelines on healing!).  The majority of treatment for tendinitis consists of anti-inflammatory medication or a cortisone shot (used only in extreme situations) administered by the physician.  The list of anti-inflammatory drugs is extensive, including as Ibuprofen, Motrin, Naproxen, Celebrex, and many more.  Physical therapists can help reduce inflammation with a number of treatment modalities (electrical stimulation, low level laser therapy, ultrasound, ice) that can decrease pain and inflammation.  The last and the most important treatment for tendinitis is a temporary discontinuation of the activity that caused this inflammation.  As stated, true tendinitis is from an acute accident therefore discontinuing that activity while the tendon heals makes sense…let’s agree to agree on this one.

Tendinosis Treatment

Treatment of tendinosis is more researched than the tendinitis.  In general, injuries that present to physical therapy and primary care doctors are tendinoses.  Remember, tendinosis develops from long-standing tendinitis and is often mistaken for tendinitis due to the increase in tendon size.  However, this increase is size is due to remodelling of collagen as opposed to the inflammation we see in tendinitis.  Recent studies show that exercise is beneficial for healing tendinosis.  More specifically, eccentric overload training appears to have optimal results.  What is “eccentric overload training”, you ask?  An eccentric exercise is an exercise that lengthens a muscle.  For example, Eccentric Overload Training - Calf Raisesif you are performing a squat, lowering your body down is the eccentric phase of the exercise on your thighs and returning to the start position is the concentric phase for your thighs.  Overload eccentric exercise training studies suggest eccentric training increases stiffness of the tendon and help change the tendon back to type I collagen.  Increasing the tendon stiffness provides the support your muscles need to contract so that it can maintain the muscle in the position where it produces the most force.  Let’s look at another example:  Achiles tendinitis is common in runners.  Mix in a little hard headedness and a desire to keep running despite injury and you have yourself the perfect storm for the development of a tendinosis.   To treat this population of patients, a 12-week exercise program consisting of heel drops has shown excellent results.  This program uses high repetitions of the exercise: 3 sets of 15 repetitions two times a day with progressively increasing external weight (you can add weight to backpack that you wear during the exercise)1. One key during this exercise is to only perform the eccentric phase of the heel drop with your injured leg.  To do this, slowly lower yourself down on the injured leg (the eccentric phase) and then return to your tippy toes by concentrically using the healthy leg.  This type of eccentric exercise can be used in any type of tendinosis.

Stat Fact: In the study mentioned, participants noted a decrease in pain from an average of 81/100 to 5/100 where 0 represents no pain1.

Double Stat Fact: Studies suggest that eccentric exercise can change tendon stiffness from a 14% loss in stiffness to a 10% gain in 14 weeks3.

Preventing Tendinopathy

Many times tendinopathies can be prevented with proper warm-up and progression of exercise.  Include proper stretching and eccentric muscle training to muscles at risk for your activity and you will have created an adequate prevention program.

Examples of eccentric exercises for common tendinopathies:Heel Drop

Heel drop for Achilles Tendinopathy:

Begin with your foot on a surface that allows your heel to drop below the height of your foot, while holding onto a handrail, banister or child (ok, maybe not a child) lower yourself slowly on the injured leg.  Push yourself back up on your non-injured leg.

Theraband ankle inversion for Posterior Tibialis Tendinopathy:

Ankle InversionBegin in a sitting position and put loop theraband (an thick elastic band) in which the loop is on the inside of your foot.  Move your foot down and in without resistance and then attach the theraband around the foot with high tension.  In a controlled manner, allow the foot return to the up and out position.

Wrist Extension and Flexion for Golfer’s and Tennis Elbow

Begin in a sitting position and allow your elbow to rest on your thigh.  For tennis elbow, begin with your hand facing the floor, with a weight in your hand.  Slowly lower the weight and then use the other hand to bring the weight back up to the starting position.  For golfer’s elbow, begin in the same starting position, but with your hand facing the ceiling and then lower the weight to the floor.

Wrist Flexion & Extension

Rehab Recommendations:

During recovery, the following recommendations should be followed for all eccentric exercises2:

  • 3 sets of 15 repetitions

  • Slow, controlled movements

  • Exercise should elicit a moderate amount of pain

  • Passive return to starting position with assistance from the non-injured side

  • Increase load when pain is minimal or absent

  • Perform exercises twice a day

  • Avoid aggravating activities for 4-6 weeks during eccentric rehabilitation



1. Alfredson H, Pietilä T, Jonsson P, Lorentzon R. Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis. Am J Sports Med.26(3):360-366.

2. Chang H, Burke A, Glass R. JAMA patient page. Achilles tendinopathy. JAMA. Jan 2010;303(2):188.

3. Narici M, Maganaris C. Adaptability of elderly human muscles and tendons to increased loading. J Anat. Apr 2006;208(4):433-443.

4. Wasielewski N, Kotsko K. Does eccentric exercise reduce pain and improve strength in physically active adults with symptomatic lower extremity tendinosis? A systematic review. J Athl Train.42(3):409-421.


02 2010

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