Patellar Tendinopathy – The role of Eccentrics.
Patellar tendinopathy can be a resistant and recurrent condition in running and jumping sports. An important part of your patient’s physical therapy program should include eccentric exercise. What are eccentrics? Eccentric contractions occur when the muscle-tendon unit LENGTHENS during exercise, producing so-called “negative work”. Squatting down is an example of a quad eccentric. Eccentric force production may exceed concentric (shortening contraction) and isometric (tensing without motion) forces 2-3 times. (Stanish et al) Eccentric training drills stimulate mechanoreceptors in tenocytes to produce collagen. (Khan et al) This effect helps to reverse the tendinopathy cycle.
The eccentric exercise commonly recommended for the patellar tendon is the squat. What kind of squat is best? A mechanism that may decrease the eccentric load on the quad is active or passive calf tension. This tension may limit the forward movement of the tibia over the ankle while performing a squat. This effect can be minimized, and load on the patellar tendon maximized, by performing a squat on a 25 degree decline. (Purdam et al) In a small group of patients with patellar tendinopathy, eccentric squats on a decline board produced good clinical results in terms of pain reduction and return to function. (Purdam et al) In the flat-footed squat group, the results were poor.
The eccentric training protocol for patellar tendinopathy should include 3 sets of 15 reps, 2 times per day, for up to 12 weeks.
“I started therapy at a rehab close to home but was not getting results after 12 visits. I then came to Chris and within 2 weeks (4 visits) the results have been substantial. What a difference!” — Kristin M.