A tendon is a non-contractile tissue at the end of a muscle. Basically, it’s the junction between a muscle and a bone. The purpose of a tendon is to transmit muscular forces to bone so that we can move. We have tendons in our knees, elbows, ankles, shoulders, spine…you name it. Unfortunately, tendons are commonly injured. In fact, tendon injuries are estimated to comprise over 30% of athletic injuries. This week’s blog is going to address tendon injuries and in particular an exercise strategy that has been shown in the scientific literature to benefit tendinopathy.
There is quite a range of severity with tendon injuries. On one end of the spectrum, we have complete tear or rupture of a tendon. This happens a lot in the shoulders (rotator cuff tears) and also in the achilles tendon. On the other end of the spectrum we see a slow degenerative process. This occurs in a repetitive strain injury, which we often refer to as a tendinopathy or a tendinosis. With tendinopathy, the tendon has been subjected to repeated stresses and it begins a cycle of breakdown and repair. This type of repetitive strain injury is very common in the general population. In fact, tendinopathy of the elbow has been estimated to affect over 15% of workers in jobs that require repetitive movement of the hand. The symptoms of a chronic tendon injury are somewhat variable but often include pain, tenderness with palpation and reduced strength.
Factors Leading to Tendon Injuries
There are many different reasons as to why people get tendon injuries. Too many to mention in this blog! Some risk factors include diabetes, obesity and hypertension. Other factors include training errors, medications, tight or weak muscles and biomechanical aberrations. As already mentioned, chronic tendinopathy related to repetitive strain is attributed to too much use of the tendon.
Eccentric Exercises for Tendon Injury
There are many different treatments for tendon injuries. Our clinic offers plenty of options. For example, Active Release Technique and Graston Technique have a reputation of resolving chronic tendinopathy very effectively. The most appropriate treatment approach depends on the extent of the injury. For example, treatment for tendon ruptures involves a much different approach than an elbow injury related to lots of typing. For this blog, we’re going to address the latter and we’re going to focus on something you can try at home; eccentric exercise.
Eccentric exercise has been shown in the literature to be quite effective for certain types of tendon injuries. An “eccentric” movement is one that lengthens a muscle/tendon while under tension. An example would be the lowering phase of a push-up. In this example, the tricep and pectoral muscles are lengthening while they are under load. For those who are familiar with resistance training, eccentrics are similar to what many call “negatives”.
Why are eccentric exercises effective?
There are different explanations as to why eccentric exercises are effective. We do know that eccentric movements place a greater load on a tendon (when compared to shortening of the tendon) so perhaps it is simply “teaching” the tendon to be stronger and subjecting it to a higher load. Loading and unloading a tendon with variable forces and speeds may assist the natural remodeling of the tendon after injury. Other theories include altered blood flow, tendon metabolism and collagen synthesis…all things beyond the scope of this blog!
A Final Word…
Eccentric movement places a larger load on a tendon than a shortening contraction. Although eccentric exercises can be helpful for certain injuries, they can also cause injury! Perhaps more than usual, we highly recommend that anyone reading this blog consults with a suitable practitioner who can assist them in prescribing these exercises. They may not be appropriate for your condition!
Over the next few weeks we’re going to post more instructions on how to properly perform eccentric exercises for various tendons in the body. For now, here are some general instructions on how to perform eccentric exercises for the Achilles tendon…more to come!
- Stand on the edge of a step with your heels hanging off the edge.
- To strengthen your right Achilles complex, raise up to your “tippy toes” by transferring your weight to the left and pushing up with your left calf (and / or your hands on the wall).
- Now standing on your toes with your heels hanging off the step, slowly transfer your weight to the right foot. Lower slowly so that your heel finishes below the step in a stretched position.
- Transfer your weight back to the left so that your left side (and your arms) bring you back up to the starting position on your toes.
- As mentioned, please consult with your rehabilitation professional who can assist with your technique and determine whether these exercises are appropriate for your condition!
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Knobloch K et al. Eccentric training decreases paratendon capillary blood flow and preserves paratendon oxygen saturation in chronic Achilles tendinopathy. Journal Orthopaedic Sports Physical Therapy 2007; 37: 269-76.
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