Current Evidence in the Treatment of Tennis Elbow

By Troy L. Grubb, PT, OCS, ATC

Many persons routinely suffer the pain and disability of elbow pain. Particularly, many suffer from tennis elbow, or clinically known as lateral epicondylitis. Despite its namesake, tennis elbow isn't necessarily due to playing tennis, rather it is a painful condition that develops over time in the tendons of the outer forearm muscles and their respective attachment site on the outside of the elbow.

It can be argued that the condition, lateral epicondylitis, is misnamed. The suffix “-itis” implies an inflammatory condition of the lateral epidondyle, or the bony prominence on the side of the elbow. Although inflammation can occur in the forearm muscle tendons, hence tendonitis, the pain that develops with tennis elbow is more likely due to pathologic tissue changes that have occurred over time that are not inflammatory in nature. It is more apt to define tennis elbow as a tendinosis—a pathologic disorganization of the tissue at the cellular level.

Tendinosis can occur in any tendon and, as well, in other tissues that encounter repetitive loading such as the plantar fascia. The pathology begins when the tendons are exposed to repetitive stress to such a degree that the rate of microtearing in the collagen exceeds the rate of repair and a vicious cycle occurs, resulting in the degradation and disorganization of the collagen fibers found in the tendon. Specifically, stronger collagen that is normally found is replaced with weaker forms, and there is loss of parallel organization of the fiber bundles. As well, histological studies of tendinosis do not reveal the widespread presence of inflammatory cells in the matrix of the tendon.

Although the pain is often mistakenly thought to be caused by inflammation, the pain from tendinosis is theorized to be due to mechanical causes (i.e. the physical microtearing and separation of collagen fibers) or biochemical causes as a result of the underlying pathology that are not inflammatory in nature, but act as chemical irritants. This may explain why non-steroidal anti-inflammatory agents don't often result in significant pain relief.

The treatment of tennis elbow often involves the use of corticosteroid injections, which have shown to provide short-term relief of symptoms. It is thought that steroid injections bathe the tissue matrix and alter the pH of the tendon, suppressing the activity of biochemical irritants in tendinosis. As well, corticosteroids may disrupt the cross-linking of disorganized collagen fibers, decreasing the mechanical strain on the fiber bundles.

Other treatment strategies that are proving to be effective in the treatment of tennis elbow include manual manipulative physical therapy, eccentric loading through exercise, and augmented soft tissue mobilization.

Manual manipulation has been shown to decrease the pain and disability associated with tennis elbow. Specifically, manual manipulation refers to physically manipulating targeted joints and tissue in the elbow and wrist. A recent study revealed that the manipulation (high velocity thrust techniques) and mobilization (low velocity oscillatory techniques) of the scaphoid (a bone in the wrist between the thumb and forearm), resulted in significantly better outcomes than exercise and modalities alone. As well, mobilization of the elbow has been shown to have a similar hypoalgesic (pain reducing) effect as spinal manipulation in the treatment of spinal pain. Mobilization of the elbow has also demonstrated an increase in grip strength in the immediate term after treatment. Manipulation of the radial head is theorized to improve the position of the radial head relative to the humerus, thus decreasing the likelihood of tissue impingement and also may disrupt fibrosis of regional connective tissues.

Eccentric loading relates to the “negative” portion of an exercise repetition. For example, with a biceps curl, the concentric (positive) portion of the repetition is the initiation of the exercise to full flexed, whereas the eccentric (negative) portion is the slower return to the start position. Simply put, an eccentric load is the very deliberate and slow return to the start position of an exercise. Research supports the model that the load imparted during this phase of an exercise repetition stimulates collagen synthesis, promoting restoration of improved collagen fiber types. It is important to note that with many eccentric loading programs prescribed for tendinosis there is often an initial increase in pain with a subsequent decrease over time.

Another form of treatment that is steadily proving to be useful is augmented soft tissue mobilization (ASTYM). ASTYM is a system of treatment that utilizes special tools to stimulate the initiation of the healing cascade to transform the injured tissue. This is accomplished through stimulation of microtrauma to the tendons and regional muscles/fascia, forcing the body to react to the stimulus triggering the healing process. The stimulus is not enough to promote injury, though. Rather, it causes the resorption of degenerated tissue, the remodeling of connective tissue, and the regeneration of more appropriate collagen types. This system is used in corporation with controlled stretching and strengthening to achieve positive results. Research is still ongoing and demonstrating favorable outcomes.

Other forms of treatment include the use of counterforce straps (tennis elbow straps) and night splints to either decrease the load demand on the tendons or to provide for long-term low-load stretching, respectively. Extracorporeal shock therapy (orthotrypsy) utilizes high amplitude sound waves to obliterate adhesions in fibrosed tendons of tendinosis, but results of studies are mixed to date.

Tennis elbow is the bane of existence for many people, often resulting not only in difficulty with sports, but even with activities of daily living and work tasks. In the treatment of tennis elbow, patience and a multi-modal approach is often key to a successful outcome. It is not common for only one mode of treatment to be effective in relieving the pain of tennis elbow, but pursuing multiple avenues of care under professional guidance can bring relief to a condition common to many and a return to normal functioning. For more information, consult your physician, the many professionals at KORT, or go to www.kort.com .

Troy L. Grubb, PT, OCS, ATC is the director of KORT – Middletown Physical Therapy. He is a board-certified orthopedic specialist in physical therapy and a certified athletic trainer. Comments or questions to tgrubb@kort.com