Our tendons are highly important structures for ensuring we can perform and train optimally. Often overlooked, tendon injury and overuse is something that needs consideration in all areas of training. Tendons are tough connective tissues that connect muscle to bone, and given the rigidity of tendons they are capable of transferring significant forces from muscle to bone for movement, as well as resisting and absorbing such forces. Tendons are able to store energy to produce explosive contractions for movements, and use the forces they absorb to then create energy for movement.
Previously, and more commonly termed tendonitis, tendons are prone to injury resulting from overuse. Recent findings have found that little or no signs of inflammation exist with tendon injury, deeming the term tendonitis somewhat inaccurate. Tendon overuse is now being termed tendinopathy, which exists as a broad term for tendon pathology and describes injury to tendon/s due to demand that are beyond its physical capabilities.
Now, there are an abundance of tendons throughout the body, and theoretically speaking tendinopathy can exist in any of them. Certain tendons may be more prone to developing signs of overuse due to many factors including: the demands on the tendon and sport just to name a common few. However, regardless of which tendon may be effected the nature and pathology of the injury is largely the same.
The most important, and probably the simplest rule with tendinopathy is that this condition does not exist without some aspect of overuse.
One of the main processes leading to the development of tendinopathy is repetitive load and excessive tendon compressive load. It is therefore important to ensure that tendons that are under high loads, e.g. Achilles tendons in runners, are well adapted and capable of recovering from such load. This can be achieved with well-planned training progressions and specific strengthening of tendons/muscles.
The treatment and rehabilitation of tendons has evolved in recent years. Current literature suggests that active rehab is most beneficial when dealing with tendon overload. Correct loading of tendons during their painful phases helps encourage repair and production of collagen fibres necessary for recovery. Given this, the risk of causing further overload is minimal if correct procedures are followed.
Without correct and early intervention and management of tendinopathy this injury is likely to progress. The progression of tendinopathy is best described by a continuum of three injury phases. Tendon injury may move between stages within this continuum, and with correct management the injury may return to previous stages.
A reactive tendon usually follows an episode of increased load, or an increase in training demands. This is a non-inflammatory proliferative response in attempt to start the recovery process. The tendon attempts to repair from the normal micro damage that occurs during activity. Pain generally subsides and function improves with adequate recovery between loading episodes.
Similar to the reactive stage, tendon dysrepair is an attempt of tendon healing. However, now with greater tendon fibre matrix breakdown further emphasis on recovery may be required. Tendon dysrepair may occur if inadequate recovery parameters have occurred after the first stage or if high tendon loading occurs in a short period of time. Changes in the tendon may now be visible on imaging such as an ultrasound or MRI. During this stage, more specific tendon strengthening may need to be integrated rather than solely allowing recovery time. Isometric and eccentric exercises are generally first point of call for introducing load, and gradual progressions are then needed to progress rehab and continue to regain tendon strength.
This is the final stage of the tendon overload continuum and injury prognosis is now poor due to permanent changes in the tendon. During this stage cell death starts to occur and significant disorganisation of tendon fibres are seen. The tendon may show areas of thickening with palpable bumps of thickened fibres. Tendinopathy is more likely to progress to this stage in the older athlete whose tendon has decreased elasticity or due to repeated overload, and failure to recognise and address the symptoms in previous stages.
In summary, tendinopathy is an injury that occurs due to tendon overload. If not recognised and addressed in the early stages, the severity of this injury is likely to progress and poorer outlooks for recovery develop. The nature of the injury is largely the same despite which tendon is effected, however the rate and type of rehabilitation incorporated will differ between tendons. Rehabilitation protocols firstly incorporate sufficient rest periods between training, before progressive loading of the tendon to stimulate collagen fibre regeneration.
Andres, B. M., & Murrell, G. (2008). Treatment of Tendinopathy. Clinical Orthopedic Research, 1539-1554.
Cook, J. L., & Purdam, C. R. (2009). is Tendinopathy a Comtinuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. Britich Journal of Sports Medicine.