Tendinopathy is a common musculoskeletal condition that can affect various tendons throughout the body. Previously known as tendinitis, which is a bit of a misnomer (as it is not considered to have a classic inflammatory response), it has commonly used names for various parts of the body that are affected, such as, Jumpers Knee, Golfers Elbow, etc. Tendons connect muscle to bone, and as such, are subject to the loads and stresses of the body during everyday life. Tendinopathy is an overuse injury characterised by localised tendon pain with loading and dysfunction, which occurs when the load placed through the tendons exceeds the load capacity of that tendon. Tendinopathy is most commonly seen in active people as an overuse injury but, can also be found in the sedentary population.
Basic Anatomy of a Tendon and Tendinopathy
Tendons are made up of very few cells with a large extra-cellular matrix (ECM). The ECM is made up of proteins called collagen that are arranged longitudinally into fibres and joined together by cross-bridges. Pathological changes that occur within the tendon at a microscopic level during tendinopathy are, for example, altered cellularity, the breakdown of the extra-cellular matrix, and collagen fibres becoming disorganised. An interesting point is that healthy tendons have very little blood supply, however within tendinopathy new blood vessels start to grow as the pathology progresses. More blood supply sounds good, but actually creates more chaos within the tendon structure.
- Healthy tendon tissue
- Degenerative tendon tissue
Australia leads the world in tendinopathy research. Cook and Purdam have created a model explaining the process of tendinopathy called the Continuum Model. According to the Continuum Model there is three stages of tendinopathy:
- Reactive tendinopathy
- A tendons rapid response to increased load. This can be caused by an acute injury, but is most commonly an effect of a sudden increase in training load without adequate rest. This is a reversible process.
- Tendon dysrepair
- This is what happens when excessive loading on a reactive tendon continues. Actual damage to the tendon structure begins to occur.
- Degenerative tendinopathy
- This is the response of the tendon to chronic overloading. It represents a breakdown of the matrix, and disorganisation of the collagen. It is important to note, that although there may be degeneration at this point, there may also be no pain, it is just a risk factor. A large percentage of the population, especially as they get older, have asymptomatic degenerative tendinopathy. So although careful loading is in order, it is something to think about – not worry about.
Risk factors
Tendinopathy is a response to overload of the tendon. There are several factors that can contribute to the increased risk of getting a tendinopathy yourself, outlined below is an example for Achilles Tendinopathy, which is a common injury in runners.
| Risk Factor | Example |
| A single high intensity session | Repeated uphill running |
| Increased frequency of training | More than five high load training sessions per week |
| Different drills | Rapid introduction of plyometric training |
| High loads when fatigued | Sprints at the end of a training session |
| Change in footwear | Less support, stiff soles, lower heel wedge etc. |
| Training with muscle stiffness | Training session following heavy weights session |
Many of these example can have a cross over to other parts of the body, such as the patellar tendon. In general, tendinopathy comes about from excess load through the tendon with inadequate rest.
Tendon Loading
Some loading of a tendon is essential in order to promote its health, as total removal of a tendon load causes a breakdown in the tendon structure, so some loading is even more important for tendinopathy. The trick is to adequately load the tendon without causing overload. Tendons adapt to physical loading, so progressive and continued loading promotes healthy and strong tendons. Interestingly, there may be no change in the imaging of a tendinopathy following a loading programme, but significant decrease in symptoms. This highlights the importance of treating the symptoms, and not relying only on the imaging to create an accurate prognosis.
Tendons adapt to physical loading in a multitude of ways, they can hypertrophy, causing an increase in the cross-sectional area (CSA) of the tendon, they can change the material properties of the tendon, or a bit of both. Either way will increase the strength of the tendon. Significant hypertrophy seems to be more of a long-term mechanical loading adaptation, whereas a change in the material properties can be done relatively short-term. The theory is that loading the tendon stimulates collagen synthesis, the more collage in the fibrils the greater amount of cross-bridges between the collagen will be formed. Cross-bridges are essential in preventing slippage between the molecules when the tendon is mechanically loaded.
Collagen production peaks approximately 24 hours following loading exercise and stays increased for around three days. In normal healthy tendons, there is a relatively high collagen content to begin with and so the increase is relatively low. But in tendinopathy, the collagen content starts off lower, but has a greater rate of collagen synthesis – strong evidence for loaded exercise being good for pathological tendons.
Exercise for Tendinopathy
For an acute reactive tendinopathy most of the evidence suggests immediate cessation of the aggravating activity with gentle isometric exercises for the first 1-2 weeks depending on pain levels. Isometric exercise is muscle contraction without movement.
There has been much debate around the correct exercise for longer-term tendinopathy. Previously, it was thought that eccentric loading, which is loading while lengthening the muscle, was the most effective way at combating tendinopathy, but that opinion has been revised in recent years as it was shown that up to 45% of patients did not respond to eccentric training.
Heavy Slow-Resistance (HSR) training has strong evidence for improvement of symptoms in patellar tendinopathy, as well as being met with higher patient satisfaction. The load intensity rather than the contraction type is the stimulus for hypertrophy in this training. HSR training involves slow eccentric-concentric contractions with progressive loading. Three exercises are performed with this training; the squat, the leg press, and the hack squat. Contractions of three seconds are ideal for each concentric and eccentric phase of the exercise, and the weight is started at around 15 repetitions maximum (RM) working down to 6 RM, 2-3 times per week over the course of approximately 12 weeks.
The most recent best practice training for Achilles tendinopathy is the Silbernagel-combined loading programme. The evidence is limited, but it has been shown in some studies to be superior to singularly eccentric loading. This programme combines the effect of eccentric-concentric exercise, eccentric only exercise, and faster loading with heel raises in a progressive way over approximately 12 weeks, dependant on symptoms.
In general, the type of exercise is not as important and will depend on your specific injury, but it should be loaded and progressive. There are a multitude of other factors that will influence the type of training programme your therapist will give you, including weakness and pain intensity.
For tendinopathy, a small amount of pain while loading the tendon is normal, but should not exceed 2/10 pain and should not linger, either immediately following the exercise or the next day – both are big signs of overload. Choose a weight that is right for you!
Summary
- A tendinopathy does not have the classic inflammatory response and so is not the same as tendinitis
- Pathology on imaging is NOT equal to pain
- Tendinopathy does NOT improve with rest – the pain may decrease, but is likely to return following return to activity
- The main risk factor for a tendinopathy is a sudden change in activity
- Exercise and loading is good for tendons
- Load needs to be initially modified and progressive
- Exercise needs to be individualised depending on your pain and function
- Tendons are slow to respond to exercise, there is no ‘quick fix’
Make sure to have your injury checked out by a therapist before commencing any loading programmes, as other pain can mimic tendinopathy, but not be improved with a loading programme. Come and check out our Sports Medicine Clinic here at Absolute Health and Performance to make sure you get the right programme for your needs!
Written by Physiotherapist Kristin Cameron | Absolute Health & Performance- Physiotherapy Services Melbourne CBD.
References
- Malliaris P., Barton C.J., Reeves N.D., Langberg H. (2013). Achilles and patellar tendon loading programmes – A systematic review comparing clinical outcomes and identifying potential mechanisms for effectiveness. Sports Medicine 43; 267-286.
- Heinemeier K.M., Kjaer M. (2011). In vivo investigation of tendon responses to mechanical loading. J Musculoskelet Neuronal Interact 11(2); 115-123.
- Magnusson S.P., Langberg H., Kjaer M. (2010). The pathogenesis of tendinopathy: balancing the response to loading. Nature Reviews Rheumatology. 6; 262-268.
- Solbernagel K.G., Crossley K.M. (2015). A proposed return to sport program for patients with mid-portion Achilles tendinopathy: Rationale and implementation. Journal of Orthopaedic and Sports Physical Therapy. 45(11); 876-886.
- Cook J.L., Purdam C.R. (2013). The challenge of managing tendinopathy in competing athletes. The British Journal of Sports Medicine. 0; 1-6.
- Malliaris P., Cook J., Purdam C., Rio E. (2015). Patellar tendinopathy: Clinical diagnosis, Load management, and advice for challenging case presentations. Journal of Orthopaedic and Sports Physical Therapy. 45(11); 887-898.
