Tennis Elbow


The condition of Lateral Epicondylitis, though commonly referred to as Tennis Elbow,  is not a condition of the elbow but tendinitis caused by repetitive use of wrist, grip, and fingers.  To better understand this,   one must gain an appreciation of our forearm muscles and their function:

Muscles which control movement of wrist and fingers originate from a common mass above the elbow jointline (1).   As the common mass muscle crosses the elbow joint, it transitions to become a tendon.     Because this is an area of transition, the muscle-tendon junction (2) tends to be weaker and is more prone to injuries.        Further down from the junction,  individual tendons  (3) begin to form from the common muscle mass,  run along the forearm, and attach to various points at the wrist (4) and fingers level (5).   

When the common muscle mass (1) above the elbow joint line contracts,  it acts as a mechanical pulley system, where the tendons in pulling their respective attachments result in wrist and fingers (or both)  extension.


In theory, tennis elbow occurs when there is injury to this pulley system at (1) the common muscle mass,  (2)  muscle-tendon junction,  (3)  tendon belly,  (4) wrist attachment,  or (5) finger attachment with the first 3 locations being most commonly seen.  This injury can either be caused by trauma (i.e. accident) or culmination of repetitive stress resulting in overload of the pulley system.    


Common complaints include pain over side aspect of forearm/elbow during:

  • Gripping (i.e. teacup,  pots/pans, tools)
  • Twisting a towel
  • Keyboarding,  use of mouse
  • Any physical activities requiring repetitive use of wrist and fingers


Tennis elbows can routinely be diagnosed by history and physical examination alone.   Exception is persistent tennis elbow which fails to respond to treatment of any kind.  Then, entrapment of nerve (posterior interosseous) needs ruling out.