Tendons are powerful, elastic, fibrous connective tissues connecting muscles to the bones. Thus, all muscles have these fibrous tissues. However, when compared to muscles, they are much thinner, with massive tensive strength. They are almost like using steel wires to connect muscles with the bones.
However, it would be wrong to view tendons just as fibers that connect muscles to bones. They also contain sensors that sense the tension and provide feedback to the brain. Thus, they play a vital role in movements.
Moreover, they are elastic and can store considerable energy. The kinetic energy produced by muscles is partially transferred to these fibers1. For example, it is estimated that almost 50% of the energy needed for running is stored in the Achilles tendon. Tendons help increase the energy efficiency of movements by temporarily storing energy.
Additionally, tendons help regulate muscle power by either attenuating or amplifying it. Thus, they act as muscle power amplifiers during jumping and similar activities1.
Though they have massive tensile strength, they are also prone to injuries. In addition, unlike muscles, they are generally slow to heal.
Types of tendon injuries
Tendon injuries are common among athletes and professional sportspeople due to the intense physical stress they endure. Consequently, most sportspeople will likely encounter tendon problems at some point. However, the terminology doctors use to describe these painful tendon conditions can be confusing for many individuals.
In medical terminology suffix "-itis" is added to indicate inflammation. Tendonitis or tendinitis are just two spelling variants used to indicate the same condition: an inflammatory condition of tendons.
Although tendonitis may indicate just any kind of tendon inflammation, it is more commonly used to indicate acute tendon injury. In addition, it is more commonly used to describe minor tears of tendons causing local pain and swelling.
Tendonitis typically arises from sudden, explosive, or jerky movements. It manifests acutely, but fortunately, most individuals experience recovery within a few days, although complete healing may take weeks. Encouragingly, nearly 80% of tendonitis cases achieve complete recovery within six months2.
This term generally describes some chronic non-inflammatory and degenerative conditions of tendons. It generally occurs due to repetitive motions. Thus, for example, the tennis elbow is not a result of acute injury, and it is caused by repetitive motion; thus, it is a case of tendinosis2.
These degenerative changes in the tendon occur slowly over a prolonged period. Degenerative changes mean a slow breakdown of the structure of tendons. Thus, these conditions are quite challenging to treat or reverse. They would often need months of treatment. Additionally, sportspeople would need to take a prolonged break for adequate healing.
Unfortunately, degenerative processes are very difficult to reverse. They tend to reoccur if similar kinds of movements are repeated in the future. With proper treatment, most would make a complete recovery. However, in one-fifth of cases, full recovery may not be possible without undergoing a minimally invasive procedure such as percutaneous needle tenotomy (PNT) and platelet-rich plasma (PRP).
Regrettably, degenerative processes are challenging to reverse and tend to recur if similar movements are repeated in the future. While most individuals can achieve complete recovery with appropriate treatment, it's important to note that in about one-fifth of cases, full recovery may not be possible without considering minimally invasive procedures such as percutaneous needle tenotomy (PNT) and platelet-rich-plasma (PRP).
In medicine suffix "-pathy" denotes a disease condition. Thus, tendinopathy means any disease condition of tendons. It is an umbrella term used to describe various tendon-related issues. However, it is more commonly used to express some chronic or reoccurring problems of tendons3.
Since it can be used to describe just any kind of tendon condition, it is always a good idea to ask doctors for more details.
Some tendons, like those of hands or Achilles tendons, are covered with a sheath (paratenon). In some cases, repeated motions may cause inflammation of the sheath, thus leading to Paratenonitis4.
It is one of the most severe kinds of tendon injuries. There may be partial or even complete tendon rupture in some extreme cases. This could severely compromise the movement of specific muscles. Treating such a condition is quite challenging. In some cases, it may require surgical correction.
Common tendon injuries
Although just any tendon may get injured, some tendons are prone to injuries. Below are examples of more common tendon injuries.
Achilles tendinitis involves inflammation of the tendon that connects the calf muscles to the heels. This tendon plays a crucial role in essential activities such as walking, running, and jumping, enduring significant stress in the process. Consequently, sports injuries affecting the Achilles tendon are common, although certain conditions like rheumatoid arthritis can also impact its health5.
Patellar tendinitis occurs due to trauma or overstretching of the patellar tendon that attaches the patellar bone to the top of the shinbone. Thus, the location of pain would be just below the knees. It is more common in sports like soccer6.
Bicep tendinitis: It is a well-known muscle of the arms. Such pain may occur in anyone who trains with heavyweights. The location of the pain is most likely to be the inner side of the elbow7.
Hamstring tendinitis: Another common tendon problem often occurring due to extreme stretching or bending. The location of the pain is in the back of the thigh.
Gluteus Medius tendinitis leads to considerable pain and a decrease in hip strength. This condition is more commonly associated with weight-bearing exercises such as squatting, although running, walking, or climbing can also contribute. A distinguishing characteristic of gluteus medius tendinitis is that the pain may radiate to the thigh, imitating hamstring tendinopathy or sciatica symptoms.
Rotator cuff tendinitis is also called swimmer's shoulder, pitcher's shoulder, or tennis shoulder. It causes pain and swelling in the front side of the shoulder, and the pain is triggered by raising or lowering the arm. It causes severe loss of mobility of the arm8.
Tennis elbow: It is a condition caused by repetitive motion. It is caused due to pain and inflammation in the outer end of the elbow. The pain is generally worse when a person tries to straighten the fingers9.
Golfer's elbow:Also known as medial epicondylitis, it affects the tendons on the inner side of the elbow. These tendons are involved in flexing the fingers, not straightening them. Consequently, pain in the golfer's elbow is experienced when bending the wrist or gripping an object tightly.
Trigger finger or thumb: A sign of this condition is when the finger clicks if straightened. The finger may remain stuck in a bent condition, thus restricting the movement10.
Wrist tendinitisis another common problem caused by repetitive motion. It can occur in athletes and non-athletes who engage in activities such as writing or typing for prolonged periods. While it can affect anyone, it is more prevalent in certain sports such as tennis, badminton, and others.
Symptoms of tendon injury
The primary symptom of any tendon problem would be pain in the affected tendon. Since tendons play a vital role in movements, thus pain would become worse when moving. However, in many cases, pain may only occur during movement. Though less common, swelling may occur, indicating a significant problem2.
Generally, tendon issues are not difficult to identify. However, one may have problems during the early stages. Tendon pains are pretty different from muscular pains. In many cases, it may cause sharp pain on movement, unlike muscular aches caused by overtraining that tend to subside after warmup. Tendon pains would not subside even after a prolonged warmup session and instead would keep getting worse.
How to diagnose tendinitis and tendinosis?
In most cases, history taking would be enough to diagnose the condition. A person reports a local pain that becomes worse when making movements and is relieved by prolonged rest periods in both situations. Additionally, localization of pain would help it differentiate from joint or muscular pains2.
In the case of tendinitis, a person would generally be able to tell the exact moment of the day when the pain began and even the physical activity after which it started. Again, this is because tendinitis has an acute onset.
On the other hand, tendinosis would start gradually, getting worse day by day. This is because the pain gets worse slowly on repetitive motions.
Doctors might sometimes use imaging methods like ultrasound and MRI to confirm the diagnosis or differentiate the conditions.
What to do about the pain?
The approach may differ a bit depending on the cause of tendon pain.
Tendonitis is about acute pain and inflammation. Thus, applying cold/ice within 48 hours may help. Additionally, adequate rest is essential for the affected tendon to recover faster. Adding over-the-counter painkillers like NSAIDs may help reduce pain and inflammation. Similarly, using topical creams may help improve local blood flow and help2.
Once the acute and painful phase is over, stretching exercises may help fasten the recovery process.
In the case of tendinosis, rest is essential as it is caused by repetitive motion. However, it is a chronic degenerative disease, and thus it will benefit more from heat therapy. One may even use infrared lamps and other ways of heat therapy. Similarly, topical applications of creams along with anti-inflammatory drugs may help11.
In the case of tendinosis, one can also include stretching exercises in a daily regime to prevent tendon contraction. However, one should always consult a specialist to avoid doing more harm.
However, if tendonitis does not get better in 72 hours or worsens, it is a reason to seek medical advice. In the case of tendinosis, seeking medical treatment is essential due to the chronicity of the condition.
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