A tendon is what connects a muscle to a bone, thus a lot of force gets transferred through a tendon during activity. There are two types of tendon pathologies aka tendinopathies. Let’s define those before we dive into treatment for tendinitis and tendinosis.
Tendinitis: a symptomatic degeneration of a tendon with vascular disruption and inflammatory repair. There will often be a sharp and localized pain with activity, first thing in the morning, and after long periods of rest.
Tendinosis: a chronic tendon injury, having a focal area of noninflammatory degeneration that may be asymptomatic. A person will feel a fairly constant dull ache that is difficult to localize (it’s difficult to put your finger on exactly where the pain is).
The progression of a tendon injury is usually linear, and follows these states:
Nirschl’s stages of tendinopathy:
Stage 0 (Healthy): firm tendon with no pain or swelling, normal temperature of tissues.
Stage 1 (Acute tendinitis): acute swelling and pain, tenderness, warmth, dysfunction.
Stage 2 (Chronic tendinitis): ongoing pain with tenderness, more dysfunction, desire to take load off the area.
Stage 3 (Tendinosis): enlarged tendon, tissue swelling, increased dysfuntion with or without pain, tendon sheath may be swollen.
Stage 4 (Rupture): weak and painful when testing muscle against resistance, inability to move the affected joint.
Tendons get injured because of the “tendon paradox“.
Oxygen consumption is almost eight times lower in tendons and ligaments than skeletal muscle. In order to protect against situations involving serious decreases in blood supply, tendons have evolved to have a low metabolic rate and a low anaerobic generating capacity. This allows them to carry loads and maintain their tension over time.
The problem develops, however, once a tendon becomes injured. Due to it’s low metabolic rate, it is very slow to heal. This may explain why tendon injures take so long to treat, and why they often develop into chronic issues. If an athlete doesn’t allow their tendon a break from the aggravating activity, the tendon will be in a losing battle against it’s own poor blood supply.
What are the factors that can cause a tendon injury? There are internal and external factors.
-Born with one longer leg
External factors (overuse and training errors consisting of):
-Faulty equipment, uneven running/playing surfaces
-Too much/too soon
-Not enough recovery time
To rehabilitate a tendon injury in the treatment for tendinitis, you can do either concentric exercises (loading the muscle and tendon while it is shortening eg. bicep curls) or eccentric exercises(loading the muscle and tendon while it is lengthening e.g. calf drops off a stair; using both legs to rise, and only the involved leg to lower).
You get more for your money doing eccentric exercises because:
-Less oxygen consumption
-More force production
-Less energy requirement
Our protocol is to start with eccentric exercises for tendon injuries. Once the athlete has no pain with walking and stair-climbing and other daily activities (not including running or playing sports), concentric exercises can be started. And once concentric exercises can be performed without pain, a gradual return to sport can happen.
Studies of Concentric vs. Eccentric Exercises:
Systematic literature reviews of tendon injuries in the lower body, found that eccentric exercises may reduce pain and improve strength, but it is not clear that this type of exercise is better than other types of rehabilitation. So exercise is just part of the picture in terms of rehabbing a tendon injury.
Other Treatment for Tendinitis and Tendinosis:
If you think you have a tendon issue, please call us at 510-465-2342 to get started on your path to healing.
Eccentric Exercise Interventions for Tendinopathies
Daniel Lorenz, PT, DPT, ATC, CSCS, USAW
National Strength and Conditioning Association Vol 32 #2 April 2010.