Investigation of a Trigger Point (TrP)

During the specific and individual medical history, the physiotherapist inquires about the areas of pain the patient experiences and precisely documents them in a body chart. Already during this process, the physiotherapist formulates various hypotheses about the main complaints, which also consider myofascial trigger points (MTrP).

As is typical in manual therapy, attention is also paid to posture and spontaneous movements (e.g., dressing and undressing) – individuals with MTrP tend to move slowly, cautiously, and try to avoid painful movements by activating the affected muscles.

Functional and movement examinations are used to objectify the hypotheses and complaints gathered during the medical history.

A muscle with active trigger points is generally functionally limited, meaning shortened and weakened to some extent.

During movements that require the full stretch of the muscle, these trigger points cause pain before the normal length can be achieved. This limitation in passive extensibility can be quickly identified by a physiotherapist. When the muscle is brought closer together, it does not cause pain. However, a contraction in this position is often painful.

A weakness caused by MTrP is assessed using specific dynamic and static muscle strength tests.

Furthermore, an MTrP can weaken or even completely abolish the muscle reflex. A slight tap on the corresponding tendon can trigger and test it. When the trigger point is released, the previously weakened reflex aligns with the healthy side within minutes.

In addition to evaluating movement restrictions, muscle length, muscle weaknesses, and muscle reflexes, precise and accurate palpation of the muscles is a central aspect of the examination. The patient should be comfortably seated or lying down so that the affected muscles are relaxed. The goal of palpation is to locate the taut band with the activated MTrP and identify it as the cause of the complaints.

An MTrP is considered the source of the complaints only if it triggers the pain described by the patient. For instance, a myofascial trigger point on the shoulder blade can cause pain on the shoulder's front side – known as 'referred pain' (radiation). These radiations of the individual TrP follow a specific pattern.