Strong fibrous tissue that connects muscle to bone is defined as a tendon. Tendons provide structural stability during body movements, but in cases of tendinopathy the tendon is diseased or dysfunctional. Symptoms sometimes include inflammatory pain. Eccentric stretching exercises effectively treat tendinopathy by reducing pain and improving strength. Extensive tendon rehabilitation usually includes eccentric exercises.
Tendon Physiology
Tendons transmit mechanical forces of muscles to bones during exercise. The largest component of a tendon is collagen. The collagen molecules form fibers, which align linearly in the direction of the exerted force. The tendon is considered viscoelastic, or viscous and elastic combined. Therefore, a tendon can stretch a certain length during exercise forces. It stretches until reaching a maximum, then the fibers begin to break and tendinopathy develops.
Tendinopathy History
The presence of tendinopathy exists in both occupational injuries and sports injuries. The Bureau of Labor Statistics reported chronic tendon injury caused 11,000 cases in 2003, which resulted in lost days from work in the United States. Achilles tendinopathy is estimated to affect 11 percent to 24 percent of runners and the rate of patellar tendinosis was found to be as high as 32 percent to 45 percent for basketball and volleyball players, clearly indicating tendinopathy as a common problem in athletes, as noted in a 2007 review by Noah J. Wasielewski, published in the "Journal of Athletic Training." Treatments for tendinopathy previously followed anti-inflammatory protocols, but most tendinopathies do not include inflammation. Current treatments include progressive eccentric exercises, eccentric stretching, concentric exercises and balancing exercises.
Eccentric Exercise Defined
Three types of exercises exist as physical therapy for tendinopathy: concentric, eccentric and isometric. Concentric uses the muscle-tendon unit to lift a load and shortens the tendon. Eccentric muscle-tendon load lengthens the tendon. It is forced to lengthen because of high external forces on the muscle-tendon unit. Isometric contraction involves muscle activation but the tendon is held at a constant length, not allowed to lengthen or shorten.
Achilles Eccentric Stretches
Physical therapy uses several eccentric stretches for Achilles tendinopathy. Prescribed progressive therapy needs adherence to avoid tendon injury. Repetitions and length of time depend on the patient's own situation. While sitting on the floor, an elastic band is placed over the ball of the foot and stretched tight, with toes pointed. Slowly the foot can be flexed toward the shin. Also, while standing with the balls of the feet on a step and standing on one leg, slowly lower the heel of the standing foot below the step, and return level to the step. Both eccentric exercises help lengthen the Achilles tendon.
Eccentric Shoulder Stretches
Shoulder anatomy includes several tendons. A rotator cuff uses muscles and tendons to connect the upper arm bone to the shoulder blade. Rotator cuff tendinopathy is common among racket sport athletes and baseball players. Also, falls involving straight arm placement frequently damage tendons in the rotator cuff. One type of eccentric shoulder exercise is done while in a sitting position. A person places their elbow on a table to form a 90 degree angle from the body, and the elbow is bent with the fist at a 90 degree angle from the elbow. Then the elbow is raised upward above the table, and lowered slowly back to the table Height of lift and repetition vary according to the patient's ability. Many eccentric stretches exist for shoulder tendinopathy.
References
- Royal National Orthopaedic Hospital: Eccentric Deltoid Exercises
- "Journal of Athletic Training": Does Eccentric Exercise Reduce Pain and Improve Strength in Physically Active Adults With Symptomatic Lower Extremity Tendinosis; N.J. Waslelewski, K.M. Kotsko; 2007
- Biology Online: Tendon
- University of Michigan: Structure and Function of Ligaments and Tendons
- University of California San Diego: Types of Contractions
- NISMAT: Eccentric Training for Treatment of Achilles Tendinosis
