Trigger point complaints

Myofascial trigger points (MTrP) are also called muscle knots. A muscle knot is a small, localized cramp in the muscle. Due to this cramp, waste products accumulate in this area. This leads to a local thickening with poor blood circulation, causing waste products to build up.
This is how trigger points with referred pain develop. Referred pain is common with trigger points, and this cramping condition in the muscle affects other parts of the body. It is possible to have multiple muscle knots in the same muscle, but at the same time, one can also have multiple muscle knots in different muscles. From the outside, these muscle knots can be felt as painful, hard lumps or bands. This can result from prolonged static tension, poor posture, or a short period of intense exertion.

According to trigger point researchers Drs. Janet Travell and David Simons, an MTrP is a highly irritable, localized spot in the muscle in the form of a small knot. Notably, a study by Travell and Simons showed that 75% of pain complaints are caused by myofascial trigger points. Treating these MTrPs can therefore be an important part of recovering from pain complaints. Read more about trigger point therapy here.

A myofascial trigger point is therefore a palpable knot in the muscle. It is painful when pressure is applied to this knot. When significant pressure is applied, it can trigger radiating pain in another part of the body. The pain can also radiate to other areas according to specific patterns. This is called ‘referred pain.’ Myofascial pain often radiates to a spot some distance from the TrP, in a pattern recognizable to the therapist. A trigger point or muscle knot can cause movement restrictions, stiffness, loss of strength, and pain. A muscle is made up of individual muscle fibers. In a normal resting state, a muscle fiber is neither stretched nor contracted. When there is a trigger point in the muscle, it appears that the muscle fibers at certain points in the resting state are more contracted than in the surrounding area.

When we talk about these muscle knots, we also often refer to a cramped muscle. But why does a muscle actually cramp? And how do trigger points develop?

A muscle can only survive in an oxygen-rich environment (alkaline). When trigger points develop in the muscle, blood flow is restricted, resulting in a gradually more oxygen-poor (acidic) environment.

A muscle can contract and relax. Both movements require energy. Contraction requires ATP, and relaxation requires ADP. So, when we cannot supply enough energy to the muscle, it struggles not only to contract but also to relax. This results in a local cramp within the muscle, leading to poor blood flow. When at rest, a muscle fiber is neither stretched nor contracted.

Above, we just talked about trigger points, but are they also noticeable to the touch? Yes, they are definitely palpable. From the outside, we can feel them by palpating across the muscle. When muscle knots are present, we feel hardened strands or bumps. When we apply slow pressure to them, they are painful and can trigger pain in another part of the body. This is called ‘referred pain.’

A myofascial trigger point can manifest in two ways: active or latent. An active MTrP causes pain or another unpleasant sensation. A latent MTrP causes stiffness and usually develops due to an inactive lifestyle with a lot of sitting, little movement, and certain eating habits.

Referred pain is radiating pain. Referred pain is the most characteristic feature of a trigger point. The pain is then perceived in a different location than where the tissue damage is situated. There are various theories about how this referred pain can arise. The most plausible theory about the origin of referred pain is that the sensory signals from the area of tissue damage reach the same part of the spinal cord as the signals from the area where the pain is felt. These signals are then misinterpreted by the brain, making the brain think that the signals are coming from the other, undamaged area. Each trigger point has a fixed area where the pain radiates. A well-known example is that headache can be the result of a TP in the trapezius muscle.

Types of trigger points

Not every trigger point is the same. This depends on the size, shape, and type of muscle in which the trigger point is located. Below is an overview of the different types of trigger points.

Primary trigger points: These MTrPs occur in the middle of the muscle belly and develop as a result of overuse. The complaints started because of these primary trigger points.

Secondary trigger points: These MTrPs occur as a result of the primary MTrP and are often seen in the muscle that assists the muscle with the primary MTrP (synergist) or in the muscle that has the opposite function to the muscle with the primary MTrP (antagonist). Secondary MTrPs are often less persistent than primary trigger points, but they do help maintain the complaints.

Attachment trigger point: This is a trigger point that is located at the attachment of a muscle to a bone.

Diffuse trigger points: These are MTrPs spread over a larger area. This can be seen, for example, in scoliosis. In this case, there are multiple MTrPs in a row.

Active trigger points: Active MTrPs are sensitive to pressure and also cause referred pain.

Inactive trigger points: Inactive MTrPs are not pressure-sensitive and do not cause pain, but they do cause stiffness in the muscle. Inactive MTrPs usually arise as a result of primary, active MTrPs and can become active through activation of the primary MTrP or due to an acute accident or injury.

The complaints caused by trigger points are incredibly varied. Trigger points have different symptoms that can indicate the presence of an MTrP. An MTrP (also known as a muscle knot) is a palpable lump in the muscle. Sometimes multiple lumps can be felt next to each other. Often, the MTrP lies within a palpable tight band of muscle tissue, which can feel like a tendon. The skin above an MTrP is often warmer or cooler than the surrounding skin. The skin above the MTrP can also be more moist. Frequently, the skin above the trigger point appears less elastic than the surrounding skin. Read more here about trigger point therapy.

It is painful when pressure is applied to this lump. The intensity of the pain depends on several factors, such as the location of the trigger point, whether the MTrP is active or not, and whether it is a primary or secondary trigger point. An important symptom of MTrP is pain according to set patterns (referred pain). The pain is then perceived in a different location than where the tissue damage is located. Each MTrP has its own area where referred pain can occur. Some examples of trigger points and the areas where pain can occur:

• An MTrP in the gluteus medius muscle can cause referred pain in the hip or lower back.
  
• An MTrP in the quadratus lumborum muscle can cause referred pain in the lower back.
  
• An MTrP in the gastrocnemius muscle (calf muscle) can cause referred pain in the plantar fascia under the foot.
  
• An MTrP in the biceps brachii muscle of the upper arm can cause referred pain in the elbow region.
  
• An MTrP in the trapezius muscle can cause referred pain to the head (headache).

Another symptom of trigger points is that the entire muscle in which the MTrP is located feels tense and stiff. One develops a limitation of movement. It may be that due to a decrease in strength, the muscle cannot be used as effectively. As a result of increased muscle tension, tendon irritations can also occur because more pulling force is applied to the attachment of these muscles to the bone. Increased muscle tension can also lead to compression of nerves or blood vessels. As a result of nerve compression, one may experience tingling, numbness, or, for example, itching.

• local, deep pain when pressing on the MTrP
  
• continuous pain without pressing on the MTrP
  
• referred pain according to fixed patterns
  
• the deep pain can feel sharper during movement
  
• a palpable nodule sometimes in combination with a hardened band
  
• the skin above a trigger point can feel warmer or cooler and may be moist
  
• increased muscle tension
  
• stiffness
  
• restricted movement and possible loss of strength
  
• tendon irritations
  
• pinching of nerves or blood vessels In addition, having trigger points can lead to reflexive body responses due to a disturbance of the autonomic nervous system. Examples of these responses include increased saliva production, redness of the eyes, a drooping eyelid, blurred vision, or, for example, goosebumps.

Trigger points can be treated in various ways. The physiotherapist can use (a combination of) the following therapy methods.

• Manual pressure techniques
  
• Dry needling therapy
  
• Trigger point therapy
  
• Stretching techniques
  
• Advice and coaching

Reduction:

• taking sufficient breaks during strenuous activities
  
• slowly stretching the affected muscle
  
• a temperature at which the body can relax, pleasant warmth
  
• physiotherapy (dry needling, trigger point therapy)
  
• breathing exercises / meditation

What makes a trigger point more painful and what reduces the pain?

Aggravation:

• too much and one-sided use of a muscle with too few breaks.
  
• an acute shortening of a muscle
  
• cold exposure (scarce clothing),
  
• stress, (suppressed) emotions and trauma
  
• too much pressure on the affected muscle
  
• unhealthy diet
  
• poor breathing

If you would like to make an appointment to be examined by a physiotherapist regarding the above, click HERE