Thanks to my friend and colleague Dr Peter Malliaras for this blog on tendinopathy – here is his bio
Painful tendon injury or tendinopathy is common and often difficult to manage. Previously this type of injury was known as tendinits, and the suffix ‘it is’ suggesting an inflammatory pathology. For over three decades now researchers have known that longstanding tendon pain may not be inflammatory, so now the popular term is tendinopathy. The pathology that is seen in laboratory studies is effectively a failed response of the tendon to adapt to forces places upon it with daily activities and sport. This is largely because tendon responds very slowly and sluggishly to changes because its infrastructure of cells and blood flow are not as extensive as some other tissues.
It is generally accepted that the key treatment for tendinopathy is exercise. Exercise is the only intervention that can restore a painful tendons ability to take the loads that it needs to in everyday function and sport. A simple formula that I use in clinical practice is to consider the loads that a patient needs to endure in their day to day function and then design an exercise program that progressively allows them to endure these loads without the tendon becoming painful. The key is to make sure that exercise is commenced at a level that will not cause the tendon to become irritable and that it is progressed at a rate that the tendon can tolerate. Every patient that I see is different and how they progress with their rehabilitation and this depends on many complex individual factors, including musculoskeletal, systemic, motivational, psychological factors, etc.
Over the last 15 years the most popular form of exercise that clinicians prescribe is eccentric exercise. This is where the muscle is loaded whilst it is lengthening (e.g. the downwards phase of a biceps curl) and is in contrast to concentric exercise where the muscle shortens whilst under load (e.g. the upwards phase of a biceps curl). An international research group I am involved with, including two physiotherapist PhD clinician-scientists (Dr Peter Malliaras, Dr Christian Barton), a Senior Human Movement Research Fellow (Dr Neil Reeves) and a Public Health Professor (Prof Henning Langberg) recently published a review questioning eccentric exercise treatment for Achilles and patellar tendon injury.
There were four studies that compared loading programs in the Achilles and six in the patellar tendon. Only two studies were rated as high quality. The most surprising finding was that very few studies have actually compared eccentric training to other forms of exercise. For example, only one study had compared eccentric training in the Achilles tendon. Overall, there was no evidence that eccentric training is better than other exercise in treating these injuries. In fact, there was equivalent (Achilles tendon) or more evidence (patellar tendon) to support exercise that involved both eccentric and concentric contractions in combination. So combined eccentric-concentric contractions may be useful in tendinopathy. Clinically, I see mainly second opinion tendinopathy cases and one of the most common reasons they have not improved with eccentric loading is that they have marked weakness of their concentric function. Due to a very well established principle of known as ‘specificity in exercise’, people will tend to get better at the type of exercise they do. So, I always give eccentric-concentric combined loading to patients with concentric weakness. Another important point is that no studies to date have investigated isometric loading in Achilles and patellar tendinopathy rehabilitation. Isometric exercise enables muscle-tendon unit load at a constant joint angle. Clinically, I use this to exercise people at a painfree joint angle that limits compression whilst still loading the tendon. Tendon compression is associated with pathology. It is very effective in the very painful or very compressive tendon presentations, and our review has highlighted that we need more research in this area.