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Tendons: Springing into Action

Tendons are probably the part of our muscles that we tend to worry the most about injuring, yet know the least about.

When you hear tendinitis, tendinosis, tendon tear or tendinopathy and the first thing that comes to mind is: ‘Oh no, now I have to stop all my sport and it’s going to take FOREVER to get better.’ Many might think that an injury to the tendon means the end of a sporting career or a very prolonged rehabilitation program.

These scenarios, while common in the thoughts of any exercising person no matter the level, are not always and almost never true.

What is a Tendon?

Tendons are bands of connective tissue that anchor muscles to bone and have the highest tensile strength of all soft tissue structures in the body – which means that the tendon is an extremely strong structure. The tendon’s main function is to transfer the mechanical force produced by the muscle to the bone in order to allow movement. They can be easily likened to a spring. This is different to a ligament which attaches bone to bone to hold a joint together, and has much less mobility and strength available.

The anatomy of a tendon looks very similar to that of a muscle, in that it is made up of bundles of fibres that continually layer to create one strong, comprehensive structure, but that is about where the similarities end.

The basic building blocks of a tendon are collagen fibres which bind together to form fibrils. Fibrils are then bound together to make a fibre, which in turn bind together to make a fascicle. The bundles of fascicles finally culminate into a tendon. Collagen fibres are strong, flexible and have elastic capabilities; the arrangement of increasing parallel bundles of fibres and fascicles create a structure that has high tensile strength and the ability absorb and release load as required for movement.

The tendon itself is divided into 3 parts with distinct characteristics: the bone insertion, the main body of the tendon and the musculotendinous junction. The part of the tendon that connects to the bone has a much denser array of collagen fibres that intermingle right into the bone and the layer of periosteum covering the bone. It is more rigid compared to the tendon body and musculotendinous junction. The musculotendinous junction is where the tendon blends with the muscle and is more elastic than the tendon body. Injuries can happen at all three parts of the tendon and they will require different healing times and possibly even treatments in the case of injury to the bone insertion part of the tendon.

Tendon Injuries

Tendon Injuries are known as tendinopathies. A tendinopathy is classified as a failed healing response of the tendon, it is a generic term used to describe pain, injury and pathological changes and inflammation of a tendon due to overuse or overload in and around tendons.

The overload causes disorganization and degeneration of the cell matrix (how the collagen is held together in parallel bundles). Previously, you would have heard the words tendinitis or tendinosis used for tendon injuries. Now scientists in the medical field believe that injuries that occur to a tendon cannot be separated into different stages or types of injury (which the above names describe). Rather, it has been shown that injuries to a tendon happen of in a continuum (gradual changes between states of the tendon). This continuum may be travelled in both directions with the correct or incorrect treatment.

Let’s look at the four main tendon states in tendinopathies:

  1. A Reactive Tendon: is the state where the tendon thickens to compensate for overload, and is the normal adaptation phase. This thickening is an attempt to reduce stress on the tendon and increase stiffness. There is no inflammatory process here and the tendon can return to the normal tendon state with correct treatment.
  2. Tendon Dysrepair: This state occurs if overload to a reactive tendon is not changed or decreased. The tendon continues to thicken and the cell matrix is further disorganized leading to breakdown of cells and an active inflammatory process. It is likely that the tendon can return to the reactive state if treated correctly.
  3. Degenerative Tendon: is the state of the tendon where cell death and degeneration are present in the tendon. This occurs when a tendon in dysrepair is not treated correctly and is irreversible.
  4. Tendon tear or rupture: This is the most severe stage and occurs when there is a catastrophic tissue breakdown, usually associated with full loss of function. If this occurs, surgery is usually the only option.

A recent update to this research shows that the tendon does not go through these stages as a whole. Rather, parts of the tendon can be normal, reactive, in dysrepair or degenerative at the same time.

To understand this theory, we can compare it to a donut. The ‘hole’ of the donut is the tendon that is in disrepair or degeneration. The ‘ring’ of the donut is the normal or reactive parts of the donut. The statement – Treat the donut, not the hole is how we approach treatment in this case, to strengthen the structures around the tendon and the healthy parts. The ‘hole’ cannot recover, yet the ‘ring’ can, to the extent that it can compensate for the injury in the hole.

General Symptoms of a tendinopathy:

  • Pain from a tendon injury is usually felt 24 hours after the activity that overloaded the tendon occurred, this can allow you to tell exactly what is causing the tendinopathy.
  • Pain may be present at the beginning of an activity, and then while the movement/activity occurs it disappears and reappears after the cooldown following an activity.
  • Pain is described as severe or sharp and can be clearly localized during the early stages, later it can change to feel more like a dull ache (if present for a few weeks).
  • Pain is located at the site of the tendon, or the surrounding tissues (usually close to the attachment to the bone)
  • Pain when the tendon is used
  • Increased pain and stiffness during the night and in the morning
  • The affected area may be red, swollen and tender.
  • Decreased strength when the affected muscle is used.
  • Loss of movement in the affected area

Where can a tendinopathy occur?

It can occur almost anywhere in the body, where there is a tendon that connects the bone to muscle. There are however a few common areas where tendinopathy occurs more regularly:

  • Base of the thumb (De Quervain’s): Pain in the base of the thumb, wrist and even in the forearm. Pain is aggravated with the use of the thumb or hand, especially grasping objects or twisting the wrist. A catching sensation might be felt when moving the thumb.
  • Elbow: this might be on the inside (medial epicondylitis/Golfers elbow) or outside (lateral epicondylitis/Tennis elbow). These injuries can be caused by activities other than golf or tennis, and usually involves activities that involve heavy use of the wrist and forearm muscles. It usually affects the dominant arm. Symptoms include pain in the elbow that spreads up or down the arm; weakness in the forearm and poor grip strength or ability to lift and move an object.
  • Shoulder: This may involve the rotator cuff muscle group or other muscles of the shoulder joint. Rotator cuff or biceps tendinopathy are the two most common injuries in this category. Symptoms might include clicking in the shoulder, pain when moving arm at about shoulder height, pain when lying on the sore shoulder. Movements such as lifting with a straight arm, moving hand behind back or stretching the arm across the body might cause pain.
  • Hip (Gluteal tendinopathy): The gluteal muscle group is a strong and large muscle group. Because of this, injuries in this area are usually due to repetitive strain over time. Symptoms include increased pain in running or hopping, increased hip pain or stiffness in the night or morning when you get up, and when you lie on the affected hip. There might be redness, swelling and inflammation of the hip bursa.
  • Knee (most common is patellar tendinopathy/Jumper’s knee): knee pain under the kneecap; that is worsened by jumping, running or prolonged sitting. Localised tenderness over the patella tendon (below the kneecap). Stiffness in the morning. Tendon thickness on the affected side.
  • Achilles tendon: Often occurs in runners or jumpers. Symptoms include pain, stiffness and loss of strength on the affected side, and are worsened when that side is used. You might feel a lump in the Achilles tendon, accompanied with redness and tenderness. Pain may vary according to load placed on the tendon.

Who gets tendinopathies?

As you increase in age (over the age of 40), your risk of developing a tendinopathy increases because the flexibility of your muscular tissue decrease and an increase in calcification can occur. Doing repetitive and higher load activities might predispose you to this injury this might be due to exercise, sport or your occupation. But tendinopathies are not limited to a specific group, anyone may get this type of injury.


The correct treatment for tendinopathy will depend on the state that the tendon is in and the site of injury. However, treatment always consists of the principles: modify the load and rest.

Rest refers to the decreasing or stopping of a specific sport or activity that is causing the overload of the tendon and causing the irritation. Modifying the load refers to adapting the load to prompt tendon healing. A tendon heals best with a load that is just above its capacity as it is then prompted to adapt and strengthen. Exercise tailored to the specific tendon’s needs is the best treatment for tendinopathies. Full recovery is judged at the point when you have no pain after applying the maximum load to the tendon you desire (ie. 24 hours after a 21km run).

Therefore it is important to note that movement and exercises are still crucial in the healing of a tendinopathy and immobility and bed-rest will almost never be prescribed. More damage can be done if the tendon is completely immobilised than when it is gradually loaded and strengthened.

Hands on treatment will initially assist in the decrease of inflammation and muscle stiffness, increase in joint mobility and general healing of the tendon, accompanied with light exercises and stretches. Following that, a more comprehensive rehabilitation program where progressive load of the tendon in applied.  It is crucial to receive and follow through with the correct rehabilitation program to ensure return to sport or activities.

Tendons are very important facilitators and forces behind movement. They allow us to expend less energy to perform high intensity and explosive movements. They are also very resilient if treated correctly after injury but it is very important to act accurately and quickly when you suspect you have tendon pain or a tendon injury.