Achilles Tendon Pain
The Achilles tendon, also referred to as the calcaneal tendon, is the thickest tendon in the human body and is located in the rear of the lower leg. It connects the plantaris, soleus and gastrocnemius (calf) muscles to the calcaneus (heel) bone. Such muscles produce plantar flexion of the foot at the ankle joint, as well as flexion of the knee (excluding the soleus).
Inflammation (Achilles tendinitis), degeneration, breakage, and getting encrusted with cholesterol deposits are all problems of the Achilles tendon (xanthomas). The Achilles tendon was called after Achilles, the Greek warrior, in 1693.
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Structure
The Achilles tendon, just as other tendons, links muscle to bone and is found at the rear of the lower leg. The gastrocnemius and soleus muscles are connected to the calcaneal tuberosity on the calcaneus through the Achilles tendon (heel bone). The tendon starts at the middle of the calf and collects muscle fibres on its inner surface, especially from the soleus muscle, mostly all the way to the bottom. It goes into the middle section of the rear of the calcaneus bone, progressively thinning downwards. At its lower end, the tendon stretches out a little, with the narrowest section around 4 cm (1.6 in) above the insertion.
The tendon is hidden below the bone and is wrapped by fascia and skin; the gap is filled using adipose and areolar tissue. Between the tendon and the top section of the calcaneus is a bursa. It measures about 15 cm (6 inches) in length. The little saphenous vein runs all along the edge of the muscle and is proximal to it. The sural nerve travels inferolateral to the little saphenous vein as it lowers in the posterior leg, crossing the lateral boundary of the Achilles tendon. The tendon is the human body's thickest tendon. Walking causes load stress of 3.9 times body weight, and running causes load stress of 7.7 times body weight.
The Achilles tendon has a low blood supply, with almost all coming from a recurrent branch of the posterior tibial artery and a few from arterial branches going via surrounding muscles.
Function
The soleus and gastrocnemius muscles act on the Achilles tendon to generate plantar flexion of the foot there at the ankle. The bottom of the foot is brought closer to the back of the leg by this action. The gastrocnemius is also responsible for knee flexion.
The tibial nerve supplies innervation to both muscles. Fibres from the gastrocnemius prefer to connect to the outer half of the bone, while fibres from the soleus likely to connect nearer to the midline, due to the tendon's 90-degree spiralling. Without eyesight, tendon vibration seems to have a significant impact on postural orientation.
In standing subjects, the vibration of the tendo calcaneus tendon generates movement backwards and the perception of the forward body tilt. Since vibrations trigger muscle spindles throughout the calf muscles, this is the case. The central nervous system adjusts by shifting the body backwards once the muscle spindles warn the brain that now the body is going forward.
Clinical Significance
Achilles Tendon Inflammation
In this case, Achilles tendonitis treatment is preferred. Achilles tendinitis is a condition where the inflammation of the Achilles tendon occurs. Achilles tendon inflammation is the pain or stiffness of the tendon, which is exacerbated by exercise and is caused by overuse. Pain and swelling around the damaged tendon are the most prevalent symptoms. The pain is usually stronger at the beginning of an activity session and lessens as time goes on. Ankle stiffness is also a possibility. In most cases, the onset is slow.
Overuse, including running, is a common cause of it. Trauma, a sedentary lifestyle, high-heeled shoes, rheumatoid arthritis, and drugs in the fluoroquinolone or steroid classes are also risk factors. Symptoms and inspection are usually used to make a diagnosis.
Despite stretching and back-strengthening activities frequently suggested for prevention, there is little data to back them up. Ice, rest, nonsteroidal anti-inflammatory drugs (NSAIDs), and physical therapy are common treatments. A heel lift or orthotics could be beneficial as well. Surgery could be recommended if symptoms persist for more than six months despite alternative therapies. Achilles tendonitis treatment can be easily found as it is a common condition.
Degeneration
MRI or ultrasound are commonly used to investigate Achilles tendon deterioration (tendinosis). The tendon is thickened in each of these situations, and the existence of retrocalcaneal, paratenonitis or retro-Achilles bursitis might cause surrounding inflammation. Tendon fibril disorganisation, Elevated blood flow, and partial thickness rips can all be found within the tendon. Tendon torn usually affects the middle of the tendon, but it can also affect the insertion, which is termed enthesopathy. Though enthesopathy is commonly connected with ageing, it is also linked to arthritis, like gout and seronegative spondyloarthritis. Calf muscle tears are believed to be linked to Achilles tendinosis.
Rupture
The rupture of the Achilles tendon occurs when the tendon splits/breaks. The abrupt development of intense pain in the heel is one of the indications. As the tendon fractures and walking gets harder, a snapping sound might be heard.
A rapid twisting up of the foot when the calf muscle is involved, direct trauma, or long-term tendonitis are the most common causes of rupture. Fluoroquinolone use, a considerable alteration in exercise, gout, rheumatoid arthritis, or corticosteroid use are all possible causes. Symptoms and inspection are usually used to make a diagnosis, which is then backed up by medical imaging. Achilles tendon rupture affects roughly one out of every 10,000 persons each year. Men are more likely than females to be afflicted. People in their 30s and 50s are particularly vulnerable.
Stretching before an activity can help prevent injuries. Surgery or a cast with the toes pointed down could be used to treat the condition. Returning to weight-bearing quite quickly (within 4 weeks) looks to be fine. With casting, there is a 25% chance of re-rupture. If proper treatment is not received within four weeks of the injury, the outcome is less favourable.
Xanthomas
Tendon xanthomas are cholesterol aggregates that form in the tendo Achilles rupture of persons who have lipid metabolic problems including familial hypercholesterolemia.
Neurological Exam
A neurological examination frequently includes an evaluation of the Achilles' tendon. A tendon hammer is used to strike the tendon during this examination. Plantar flexion (downward movement) of the foot is a natural reaction to this examination of the S1 and S2 spinal neurons.
Level or Portion of Tendon Affected
Insertional - Overuse injury is a common occurrence among running and jumping sportsmen. Patients with insertional Achilles tendinopathy experience discomfort on the back of their heels, and also morning stiffness, edema with activity, and discomfort at the tendon's insertion point.
Paratendinopathy - A connective tissue sleeve that covers the tendon and defends it from friction, irritation, and recurrent stress is inflamed.
Mid-Portion: The Achilles tendon insertion into the calcaneus is roughly 2–7 cm away. This level is characterised by a combination of discomfort and edoema. It has been linked to a significant drop in performance.
FAQs on Achilles Tendon
1. What is the Achilles tendon and what is its primary function in the body?
The Achilles tendon, also known as the calcaneal tendon, is the thickest and strongest tendon in the human body. It is a band of fibrous tissue that connects the calf muscles (gastrocnemius and soleus) to the heel bone (calcaneus). Its main function is plantar flexion of the foot at the ankle joint, which is the movement required to point your toes downwards. This action is essential for walking, running, jumping, and standing on tiptoes.
2. Why is the Achilles tendon named after the Greek mythological hero Achilles?
The tendon is named after the Greek hero Achilles. According to mythology, his mother made him invulnerable by dipping him in the River Styx, but she held him by his heel, leaving that one spot unprotected. This became his only weakness, and he was ultimately killed by an arrow to the heel. The name is used metaphorically to highlight the tendon's critical importance and its vulnerability to injury, representing a single point of failure.
3. What is the difference between Achilles tendonitis and a complete Achilles tendon rupture?
The primary difference lies in the nature and severity of the injury.
- Achilles Tendonitis: This is an overuse condition where the tendon becomes inflamed, causing pain and stiffness. The tendon fibres are still intact, but are irritated, often due to repetitive stress.
- Achilles Tendon Rupture: This is an acute injury where the tendon fibres tear, either partially or completely. A rupture is often accompanied by a sudden “pop” or snapping sensation, severe pain, and a loss of function, making it impossible to push off the ground with that foot.
4. What are the most common symptoms of an Achilles tendon injury?
The common symptoms of an injury to the Achilles tendon include:
- Pain and swelling in the back of the heel, especially after physical activity.
- A feeling of stiffness in the tendon, particularly in the morning.
- Tenderness when the sides of the tendon are squeezed.
- In case of a rupture, a sudden, sharp pain and a popping sound at the time of injury.
- A noticeable gap or depression in the tendon, about two inches above the heel bone.
- Difficulty walking or standing on the toes of the affected leg.
5. Why is the Achilles tendon particularly prone to injury, especially in athletes?
The Achilles tendon is vulnerable to injury because it endures immense stress, equivalent to several times a person's body weight during activities like running and jumping. Key reasons for its susceptibility include:
- High Tensile Loads: Sudden starts, stops, and pivots in sports place huge forces on the tendon.
- Poor Blood Supply: A specific section of the tendon has limited blood flow, which hinders its ability to heal from minor, everyday wear and tear, making it weaker over time.
- Overuse: Repetitive strain without adequate rest can lead to inflammation (tendonitis) and degeneration.
- Tight Calf Muscles: Inflexible calf muscles increase the strain on the tendon, making it more likely to tear.
6. Can a torn Achilles tendon heal on its own without surgery?
Whether an Achilles tendon can heal without surgery depends on the severity of the tear. A partial tear might heal with non-surgical methods like immobilisation in a cast or boot, which keeps the foot pointed downwards to allow the tendon ends to reconnect. However, for a complete rupture, surgery is often recommended, especially for younger, more active individuals, as it typically results in a stronger repair and a lower risk of re-injury compared to non-operative treatment.
7. How do stretches and proper footwear help in preventing Achilles tendon injuries?
Stretches and proper footwear are crucial for preventing Achilles tendon injuries. Regular stretching of the calf muscles helps maintain flexibility, reducing the amount of pull and tension on the tendon during movement. Proper footwear provides essential support to the foot and arch, ensuring that force is distributed evenly during impact activities. Shoes with adequate cushioning and a slightly raised heel can decrease the strain on the Achilles tendon, lowering the risk of inflammation and tears.
