In the world of the back, the most known symptom is muscle contracture. These are “knots” that we can touch in our muscles and our physiotherapist sometimes works to relieve the pain. Despite the known muscle contractures for the whole world, few people understand why they appear, what function they perform and what to do with them.
A clarification before proceeding. At all times I will refer to contractures that occur in healthy muscles previously as a consequence of back injuries. I am not talking about the term contracture that refers to the shortening of the muscle due to abnormal postures maintained that we see especially in neurological injuries such as hemiplegia. The same word is used but different concepts. Today we are going to talk about the muscular contracture that we have all felt and know.
Muscle contracture Let’s explain first of all what a muscle contracture is. The muscle has a fibrillar structure that has the ability to shorten its length. If we look at the muscular fibers of the scheme we can see how they are intertwined with each other. These fibers have a certain length if the muscle is relaxed or with its basal tone. When muscle contraction occurs the muscle shortens and widens. we see the man in the picture we can see how he “pulls a ball” by flexing the elbow and contracting the muscles of the arm. The contraction of the muscle makes it bend the elbow because it pulls the forearm towards the arm. During muscle contraction the muscle fibers are interlaced so they shorten in length and increase in width, so we get that “ball”. This is what we call muscle contraction. We speak of muscular contracture when in certain areas the muscle does not return to its resting position.
A patient may start with neck pain for example by noting a contracture in the trapezius muscle that causes discomfort and even headache. Although this is the main symptom does not mean that it is the cause of the problem. The origin or cause of the contracture may be in the muscle itself or be a secondary reflex to another injury. Let’s go see it.
1 – In very young people more often the cause of the contracture is in the muscle itself.
A – If we make repeated efforts above the resistance capacities of that muscle, contractures will appear. This is seen for example in a worker who is at the computer for many hours and is adopting incorrect postures with excessive activity of neck muscles. When the muscle is tired, contractures will begin.
This happens among other things by how the metabolism of the muscle works. To not make it very complicated I will summarize it in an easy way. The energy consumed by the muscle actually spends during the relaxation phase. The ATP is the energy unit that gets the muscle to relax and is ready for a new contraction. Somehow it is as if our relaxed muscle was like a loaded shotgun ready to contract and we need the energy to reload it (relaxation phase).
B – At other times an intense punctual effort that exceeds the capacities of the muscle will end in an injury in the form of a larger or smaller fibrillar rupture. These lesions generate inflammation and contractures in the muscle itself.
2 – In many cases the origin of the problem is not in the muscle. If I do a cervical sprain, the damage is in the ligaments and cervical joints (assuming there is no damage in the muscle that sometimes there is also). With this type of injury I can also suffer contractures. In this case the damage is not in the muscle. The muscle is contracted with the aim of protecting damaged joints and ligaments. The contracture generates rigidity and limits the mobility of the joints. It is a mechanism that starts the body to facilitate the repair of the damage. For this protective function, in addition to other reasons, it is not good to receive massages the first few days after suffering an injury of this type and we can notice a worsening.
This situation where the damage is not in the muscle is what we see most frequently in a medical consultation. A cervical pain or low back pain with significant involvement has injuries to the joints and ligaments. The patient noticed the contractures and can be seen in the physical examination but they are not the cause, they are the consequence. Treating these contractures can be a great help and will alleviate the symptomatology but it is not what will give us the cure.