Understanding tendinopathies (part 1)
Tendons are an integral part of the musculoskeletal system, serving as connectors between muscles and bones to facilitate movement and provide stability.
However, like any other tissue in the body, tendons are susceptible to injury and degeneration, leading to a condition known as tendinopathy.
This condition is common when there is a sudden increase in the overall load these tendons can accommodate. This might happen for those preparing for a running event or who are attempting a challenging new gym program.
The tendons don’t have sufficient time to adapt physiologically to these new demands and the consequence is the gradual loss of tendon health.
But before we dive further into how tendon injuries occur, let’s look at what at tendon is.
What is a tendon?
Tendons are dense, fibrous connective tissues composed primarily of collagen fibres.
They are designed to withstand tension and transmit forces generated by muscles to bones, enabling joint movement.
Collagen fibres are flexible, strong and are resistant to damage. Their structure is similar to a rope, with the small collagen fibres arranged in bundles which reinforces the tendon and makes it stronger.
The function of tendons
The primary function of tendons is to transmit forces from muscles to bones, allowing for movement across joints.
During muscle contraction, tendons stretch and recoil, storing and releasing elastic energy, which enhances movement efficiency.
Additionally, tendons provide stability to joints, acting as passive restraints against excessive motion.
Understanding tendinopathy
Tendinopathy refers to a spectrum of tendon disorders characterised by pain, swelling and impaired function.
The exact cause of tendinopathy is multifactorial - involving mechanical overload, vascular insufficiency, inflammation and impaired healing response.
According to Steinmann et. el. there are a multitude of risk factors that can trigger tendon disorders and individual patient characteristics (i.e. genetics) habits (e.g. smoking and alcohol) and activity levels can contribute to the condition.
How tendinopathies occur
There are many factors that can lead to a tendinopathy injury, such as:
Overload and repetitive stress: one of the main causes of tendinopathies is overuse or repetitive stress on the tendon. Activities that involve repetitive motions or excessive loading can lead to microtrauma within the tendon structure. This is particularly applicable when there is a sudden increase in training duration, frequency or intensity within a short timeframe.
Poor biomechanics: faulty biomechanics, such as improper technique during physical activities or inadequate equipment, can contribute to the development of tendinopathies. Poor alignment, muscle imbalances and incorrect movement patterns can place abnormal stress on tendons, leading to tissue damage over time.
Age-related changes: tendons undergo natural aging processes that can predispose them to degenerative changes and increased susceptibility to injury. As individuals age, tendons may experience a decrease in collagen synthesis and alterations in matrix composition, impairing their ability to withstand mechanical stress and recover from injury effectively.
Vascular insufficiency: adequate blood supply is essential for tendon health and repair. Vascular insufficiency can compromise blood flow to the tendon, impairing its ability to heal and maintain structural integrity. Conditions such as diabetes and peripheral vascular disease may exacerbate vascular compromise and increase the risk of tendinopathies.
Genetic predisposition: certain genetic factors may predispose individuals to develop tendinopathies. Variations in collagen genes, enzymes involved in collagen synthesis and degradation, and other genetic polymorphisms can influence tendon structure, function and susceptibility to injury.
Elevated cholesterol: high cholesterol is a risk factor for tendinopathy.
Hormones: women are more susceptible to tendinopathy throughout menopause, which is likely due to reduced eostrogen levels.
The result of these combined influences is a gradual degenerative change in the tendon structure.
This process begins with damage to the collagen fibres within the tendon. As the condition worsens, cellular behaviour in the tendon is altered, which then affects its ability to repair and remodel, leading to further loss of tendon health.
Tendinopathy doesn’t typically involved inflammation. The pain mechanism behind tendinopathies is usually biomechanical (i.e. the stretching or compression of tissues).
In part two of this blog post series on tendinopathies we will discuss why pain exposure and load tolerance is therefore an important part of recovery.
Common signs of tendinopathy
Pain: pain is the main symptom of tendinopathy and typically worsens with activity. It may present as a dull ache, tenderness or sharp pain localised pain to the area. The pain may limit movement and impact daily activities.
Decreased function: tendinopathy can result in decreased range of motion and strength, affecting the functional capacity of the affected limb or joint. Activities that require repetitive or forceful movements may exacerbate symptoms and further impair function.
Stiffness: tendon stiffness is a common feature of tendinopathy, characterised by reduced flexibility and increased resistance to stretching. Stiffness may contribute to movement limitations and compromise joint biomechanics.
In conclusion, tendinopathies are complex musculoskeletal disorders characterised by pain, swelling and impaired function.
Understanding the structure, function, and disease process of tendons is essential for effective diagnosis and management.
Stay tuned for part two in our tendinopathy serious on how we manage tendinopathies, including early interventions and how to approach training when tendon pain occurs.
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