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Trn v peti


Causes, signs, stressors and user experiences of spruce products

Author: Matic Konc

resources used

published: 7/2/2019

A thorn in the heel is an extended term for a bony outgrowth or osteophyte that forms on the heel in the direction of the arch of the foot and can be a pointed, hooked or shelf outgrowth and can measure more than 1 cm in length . Although it is often painless, it can also cause severe pain. In the population, it occurs in one in ten people, and pain in the fifth in only one in twenty.



In 10-63% (various studies) the thorn in the heel does not cause any problems and the individuals who have it do not know about it at all, but it is discovered by chance . It is also not necessary that every heel pain is associated with a thorn. In 45% of people who have pain, a thorn  is not present but the heel pain arose for a different reason .
The thorn in the heel itself does not cause pain. The pain depends on the shape, size and location and is due to pressure on the nerves and inflammation of the surrounding tissue . If the inflammation of the surrounding tissue is eliminated, the improvement can be permanent in up to 97% of cases, despite the fact that the thorn remains.

A thorn in the heel can cause pain


A sharp, stabbing pain that people compare to walking on the tip of a knife , which eventually turns to blunt. The pain is usually more severe in the morning or after prolonged rest. The first few steps are extremely painful, then the pain subsides slightly. The dull pain persists all the time.

A thorn in the heel can be accompanied by numbness in the foot


 People who have a thorn in the heel often suffer from stiffness of the heel, ankle and shin muscles, which normalizes after a few initial steps.

Ants in the foot


If a thorn in the heel presses on a nerve , this can manifest as tingling in areas of the sole


Since cases of thorn in the heel in children are also documented, we can conclude that at least in a minority of cases it is a thorn as one of the ways of normal development of the heel. The causes of heel spur formation are not yet completely clear, but two different ones are found in the literature  theory:


Vnetje tetive stopalnega loka ali plantarni fasciitis

The most widespread theory, which is slowly being abandoned,  is  that the thorn appears with repeated loading of the tendon of the arch of the foot (platar fascia) on its increment on the heel. This is supposed to cause chronic inflammation and thorn development in the heel. Tendon tension is higher if the arch of the foot is lowered , and tension is also higher if there is more pressure on the arch of the foot due to being overweight. This theory is supported by the fact that the thorn in the heel does not appear inside the tendon itself , as is usually the case with calcifications due to tendon and ligament strain, and that the condition recurs in almost half of cases after surgical removal of the thorn and relaxation of the arch. This theory is also contradicted by the fact that in 10 to 63% (various studies) of people who have a thorn, pain has never been present .



Heel spurs can be caused by vertical stress

Recent research finds that the thorn in the heel may be due to the heel’s response to repetitive, vertically directed heel loading . The heel carries most of the force of body weight, and bone growth is a dynamic process that adapts to the direction of the force to which it is exposed ( Wolf’s law ). The thorn in the heel is thus formed as a result of the repetitive vertical force acting on it. Repeated loading of the heel causes repetitive microdamages that cause bone growth. It is actually a defense response of the organism , when due to overweight and aging, degenerative processes of soft tissue under the heel (fat pads) begin, which otherwise cushions the blows to the heel. The thorn is formed to replace the function of the worn tissue and to soften the forces on the muscles and other tissue surrounding the heel. 
Studies have shown that a single heel injury does not yet cause a thorn to form in the heel, but if the injury is constantly recurring due to thinned protective tissue and being overweight, thorn formation can occur, especially if other risk factors are present, such as are genetic factors ( gait, elasticity and thickness of fat pads, arch structure ) and the footwear we wear.


  • With aging  the chance of a thorn appearing in the heel is greater. Some studies find that 62 and even up to 98% of people who have a thorn in the heel are over 40 years old. With age, the way of walking also changes so as to reduce the length of the stride and prolong the contact of the foot with the ground, which could play a role in the formation of a thorn in the heel.

  • Being overweight greatly increases the chance of a thorn forming in the heel. 46 to 82% of people who have a thorn in their heel are overweight. Diabetes is also associated with heel spurs, but it is not entirely clear whether this is an independent risk factor or simply due to the fact that diabetes is more common in overweight people.

  • Foot position: Thorn in the heel and flat foot or. inward-facing feet are statistically strongly related, as 81% of people who have pain due to a thorn in the heel also have a flat foot.

  • Gender : There are various findings in the literature regarding gender as a risk factor for heel spurs. Studies looking at the elderly population usually do not reveal a significant difference in the incidence of thorn in the heel between men and women, whereas in the population under 49, the thorn is more common in women than in men. The authors attribute the difference to wearing high-heeled shoes .

  • Arthritis : Heel spur is more common in people with arthritis, in people over the age of 61, even in 80% of people with osteoarthritis and in 72% of people with rheumatism .

  • Inflammation of the tendon of the arch of the foot : a thorn in the heel is present in 45 to 85% of people who have plantar fasciitis or. inflammation of the tendon of the arch of the foot. Also, both conditions share many other risk factors, such as being overweight and age, so they most likely have a similar cause.  Inflammation of the tendon of the arch of the foot or plantar fasciitis occurs due to mechanical overload of the tendon, which causes micro injuries. Repetitive heel injuries and strains complicate the regeneration process, leading to chronic tendon inflammation. The tendon therefore transforms and fibrosis and calcification occur at the growth of the tendon on the heel and the formation of a thorn in the heel.

  • Genetic factors : There is a greater chance of a thorn in the heel in individuals who have genetic predispositions for faster bone formation in response to mechanical stress. This explains the fact that in some individuals a thorn appears and in others it does not, even though they are exposed to the same or even greater loads.


  • Inflammation of the tendon of the arch of the foot (Plantar Fasciitis):  The tendon of the arch of the foot is a thick band of connective tissue that connects the heel to the front of the foot and provides support to the arch of the foot. Inflammation of the tendon of the arch of the foot is the most common cause of heel pain. The thorn in the heel is most often present in Plantar fasciitis. The signs are pain  or heel tenderness, which worsens after rest, when standing on toes, and climbing stairs. It is often characterized by a smaller spot that is particularly sensitive to touch

  • Achilles tendonitis:  It is the most common cause of pain in the back of the heel. It is an inflammation or degeneration of the Achilles tendon. The Achilles tendon attaches the triceps to the heel. The cause of inflammation is an excessive or repetitive load on the tendon . Signs of inflammation are pain in the back of the heel, which is worse after rest or in the morning, swelling and stiffness of the soft muscle.

  • Heel fracture:  One or more cracks in the heel cause severe pain in the heel. Fractures can occur with repeated overloading of the heel, such as jumping, landing or running barefoot on a hard surface. Pressure pain and swelling are characteristic.

  • Inflammation of the retrocalcaneal bursa is an inflammation of the mucous sac between the heel and the Achilles tendon. The cause of inflammation is a load due to tight muscles or a sudden increase in physical activity. It is characterized by pain in the back of the heel during walking, running or standing on the toes, sensitivity to touch, swelling, redness and locally elevated temperature.

  • Sever's disease is the most common cause of heel pain in children, most commonly in boys. It is an inflammation of the apophysis of the heel due to overuse and disappears on its own at rest.

heel with question mark.jpg



What is a thorn in the side?

The thorn in the heel is called a thorny bone growth that occurs with aging, as a result of increased load on the heel bone due to thinning of fat pads, excess weight, etc. The pain that is present is caused by inflammation of the soft tissues around the heel. A single answer to the question of whether a thorn in the heel is caused by inflammation of the soft tissues in the foot or whether the soft tissues become inflamed by a thorn in the heel has not yet been found by experts.

What helps for the thorn in the heel?

The cause of heel pain is inflammation. Whether the thorn in the heel is its cause or its consequence is not essential (the profession is not yet unified). It’s entirely possible that you’ve had a thorn in your side present for decades, but so far you didn’t even know about it. We recommend that you apply Spruce 365 spruce cream to the Spruce coating and apply it to the heel with the greased side. If at all possible, keep the lubricated lining attached day and night. Within two weeks, in most cases, you can expect a 60-80% improvement.

Why does a thorn form in the heel?

Over the years, the fat pads that protect the heel bone wear out. The bone is more exposed to the vertical load and is defended by the growth of the osteophyte in the direction of the load.  Many times, the thorn in the heel is also associated with inflammation of the tendon of the plantar arch, but it is not entirely clear what is the cause and what is the consequence. The pain that is present when we are stung by a thorn in the heel is always the result of inflammation of the soft tissues around the heel. The thorn in the heel can be present for many years, and the pain occurs when there is inflammation of the soft tissues.

How long does the pain caused by the thorn in my heel last?

When using Spruce 365 in combination with Spruce coating, the pain in the heel spur usually decreases by 60 to 80% in two weeks, then slowly improves day by day and eventually disappears.


How to remove a thorn in the heel?

The pain that accompanies the thorn in the heel is due to inflammation of the surrounding soft tissues. When the inflammation is eliminated, the pain ends, and research shows that it is only rarely repeated in a later period of life. The bone growth itself remains, but if it does not cause problems, it makes no sense to remove it. It is quite possible that you have had a thorn in your side for decades, but you did not know about it until the pain appeared. Shock depth wave therapy is most commonly used to remove the thorn on the heel.

Why do you recommend Spruce Wrapping?

First of all, it should be noted that Spruce coating is not recommended in combination with Spruce Extra products. The use of Spruce coating is strongly recommended when using Smrekovit 365 spruce cream and Smrekovit Klasik spruce ointment. The price of spruce linings is intentionally low because it only serves as an aid to spruce products. The use of spruce wraps greatly increases the performance of the products because it acts as a reservoir for the cream or ointment so that the active ingredients from the spruce resin can be continuously absorbed into the tissue as much as it can absorb. In places where the Spruce dressing can be easily attached and stays in place, we recommend using the wrap all the time and homework once a day (lubricate the wrap). On more flexible joints, where the lining likes to curl and move, use it at least overnight, and lubricate this part several times during the day.

Why do you discourage the use of ice or some other method of cooling?

First, let’s ask ourselves what does ice cause? Cooling slows down the physiological process caused by tissue damage or inflammation. At the site of inflammation or injury, the permeability of the vascular walls increases in order for the body to allow inflammatory cells (leukocytes and lymphocytes) and inflammatory proteins to pass to the site of inflammation. The purpose of this process is to confront the defense mechanism with inflammation in order for the organism to eliminate it on its own. The visible consequence of this process is swelling, which is a completely normal phenomenon, as every cell and protein that passes to the site of inflammation is surrounded by a mantle of water and because inflammatory proteins penetrate the site of inflammation and cells pass water with them.

By cooling, the patency of the vascular walls is reduced again, so the swelling is also reduced, but consequently the treatment time is significantly extended.

Spruce resin causes the opposite and stimulates the body's defense mechanism and consequently significantly reduces the treatment time. It is clear, then, that refrigeration and the use of spruce resin products are contradictory.

You can also read more about this topic in an article on our blog: Led Vs. resin or even a donkey should not go on the ice even once


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