A Comprehensive Look at Tendinitis:  Part I – A Definition and Common Causes

Orthopaedic & Spine Center

Boyd W. Haynes III, MD

One of the most common problems for which I see patients is Tendinitis, Tendonitis, or Tendonopathy.  Derived from tendon (Greek for to stretch) – a thick, fibrous cord that attaches muscle to bone and itis – a Greek derivative meaning inflammation, an inflamed tendon can be quite painful and limit your daily activities.  Tendons are covered by a sheath of connective tissue.  If the tendon sheath, but not the tendon, becomes inflamed, the condition is called tenosynovitis.  The two conditions can occur simultaneously, causing a perfect storm of pain, swelling and stiffness.

Tendinitis can be caused by years, months or a few days of overuse or it can occur immediately after an injury that happened during sports, a workout or other vigorous activity or job.  As we have tendons throughout our body, most parts of the body can be affected, but some tendons are more prone to inflammation than others.  Tendons in the elbows, hips, knees, shoulders, the base of the thumb and the Achilles Tendon are commonly affected.

Weekend warriors (those who are only active or play sports on the weekend) are notorious for reporting tendinitis.  Tennis, golf or pitching sports (baseball, softball, cricket) are big offenders, but any sport can cause tendon inflammation.

Everyday chores, such as raking, painting, carpentry, scrubbing and cleaning can cause tendinitis. The key aggravator seems to be a repetitive motion, vibration or that is performed excessively or which causes the strain and inflammation.   Even playing video games or taking selfies with our phone can cause tendinitis, if done repetitively over time.

Tendinitis can also be caused by medical conditions or abnormalities in the structure of the body.  People who have auto-immune diseases (rheumatoid and psoriatic arthritis) and gout are more prone to develop it.  People who have thyroid conditions or diabetes are more at risk.  Those who have limb length differences, arthritis or scoliosis of the spine can see an increase in tendinitis, because the body/limb/joint may be weak and out of balance.  The body tries to compensate for the differences, putting strain on tendons.  An infection caused by the bite of a dog or cat can result in tendinitis.

Age plays a big role in the development of tendinitis.  People over the age of 40 are much more susceptible to its development.  As we mature, the tendons lose strength and elasticity; thus, they are more prone to stress and tear more easily.

Gender most certainly plays a role.  Women are prone to some types of tendinitis, such as tendinopathy of the glutes and DeQuervain’s tendinitis (base of thumb), especially during pregnancy. Men are more prone to Biceps tendon ruptures and Achilles Tendonitis.  We are not sure exactly why, but body type, strength, genetics and hormones all contribute to the development of certain kinds of tendonitis.  Men’s tendons are stronger and have more collagen than the tendons of females.

In Part Two – I will discuss the symptoms and how I diagnose Tendinitis.