The Science of Tennis Elbow

Tennis elbow is a nagging, painful condition that afflicts 6.5 to 9.5 million Americans each year, typically aged 40-60. But people who play tennis make up less than five percent of all reported cases. In fact, tennis elbow affects anyone who performs repetitive movements with their arms, such as golfers, manufacturing and construction workers, plumbers, cooks, mechanics, musicians, gamers, carpenters and even heavy computer users.

Not only is “tennis elbow” a bit of a misnomer, but the clinical term, lateral epicondylitis, is also misleading. Words ending in “-itis” imply inflammation, and yet this condition instead should be considered a tendinopathy or tendinosis. Understanding the science helps to determine treatment for tennis elbow, and ultimately promote recovery.

Definition and Symptoms

Tennis elbow is a repetitive strain injury that results from chronic overuse of the muscles and tendons in the forearms. Over time, repetitive movements can weaken the extensor carpi radialis brevis (ECRB) muscle and cause tears and inflammation in the two forearm tendons, the extensor carpi radialis brevis and the extensor digitorum communis, which attach to the epicondyle (bony protuberance) on the radius bone.

These tears can cause achiness in the elbow and difficulty gripping, grasping and lifting. Other symptoms can include pain radiating from the elbow down the arm, sharp twinges when using the arm and elbow, pain in the wrist and numbness or tingling in the fingers. Shaking hands, lifting a coffee cup, turning a doorknob, brushing teeth or even cutting food can be difficult.

Although symptoms usually are mild initially, they tend to worsen over time. And this degenerative condition generally does not go away on its own, but becomes chronic without treatment.

Science of Tendons

Tendons are tough, fibrous connective tissue that attach bones to muscles and stabilize joints. They are primarily composed of collagen and elastin, and have a limited blood supply and poor circulation.

Tendons also have a tendency to break down and degenerate over time, and they don’t heal well due to their limited blood supply.

Tendinitis or Tendinosis

Tendinopathy refers to any painful condition in and around the tendons due to overuse. Tennis elbow, or lateral epicondylitis, implies inflammation of the tendon. Inflammation causes pain, swelling, warmth and redness.

However, research has shown that beyond the early stages, inflammation isn’t evident in tennis elbow. According to one study, “signs of either acute or chronic inflammation have not been found in any surgical pathologic specimens in patients with clinically diagnosed tennis elbow.” In fact, the histology of tennis elbow indicates that it actually is tendinosis.

Tendinosis refers to the degeneration of the tendon’s collagen in response to chronic overuse. There is a loss of collagen continuity so that fibers are no longer aligned and an increase in ground substance, which is the fluid component of connective tissues. The tendon changes from being white and firm to brown and soft, but there is little evidence of inflammation.

Understanding the difference between tendinitis and tendinosis is important for proper treatment. While rest, ice and anti-inflammatory medication like ibuprofen can address initial inflammation and alleviate, they are not effective long-term solutions for recovery.

To promote healing in tendinosis, tendons must have increased circulation, which brings oxygen and healing properties to stimulate healing and the synthesis of new collagen. Increased vascularization is facilitated by deep friction manual therapy on the forearm, which facilitates fibroblast formation and collagen production.

Stretching and strengthening exercises for the forearm also are helpful to increase blood flow to the area, preserve range of motion and stimulate collagen cross-linkage formation, which helps strengthen the tendon.

Tennis elbow can recur over time, so ongoing stretching and strengthening, along with warming up before activity, can help prevent re-injury.