To accurately diagnose Chronic Myofascial Pain (CMP), a thorough history and
physical evaluation are essential. The history should include a detailed pain
history, including when and how the pain started, the exact location of the pain, what
it feels like, which treatment modalities have been attempted (and their results), and
any history of trauma, overuse, or concurrent illness. The patient should point to the
exact location of the pain, rate the pain on a scale of 0 to 10, and review what makes
the pain better or worse.
A thorough physical examination should be performed, with a focus on the area of pain
and discomfort. The physician should start by observing the patient's movements and
posture, looking for poor posture, muscle strain, pain that increases guarding, and
increased pain in other muscle groups. Trigger points cause muscle shortening with
secondary weakness and decreased range of motion; therefore, a complete musculoskeletal
exam with strength testing and relevant neurological assessment is essential. Tension and
spasm in muscle groups should be assessed.
To make identification of trigger points easier, the patient should be as relaxed as
possible. Trigger points can be felt by palpating the muscles; trigger points will consist
of tender, hard (or ropy) knots or nodules surrounded by what feels like normal muscle
tissue. Once a trigger point has been found, the local twitch response may be elicited
as muscle or skin twitching1.
Next, the patient should be evaluated for referred
pain. Knowledge of reference zones is essential to the diagnosis.