Causes of Myofascial Pain

Similar to headaches, the exact cause of myofascial pain appears to be unknown. However, there are some working theories that might help to explain the symptoms of myofascial pain. One underlying cause appears to be muscle injury or repetitive strain, which activate myofascial trigger points. Another cause might also be psychological stressors and physical strain because both can increase muscle tension along fibers referred to as the taut band, which is a hardened ropelike stretch of muscle fibers in which triggers are present. Lastly, myofascial pain might originate from postural stressors, such as poor body posture while sitting at a desk, which is held for prolonged periods of time.

When a trigger point within the muscle is activated, the muscle fibers contract, which results in a sensation from trigger point activation that may take the form of referred pain, or pain in an area other than the point of origin. For example, a trigger in the trapezius muscle, which helps raise the shoulder, can shoot pain up the shoulder to the neck and head, and can be experienced as a headache.

It is believed that active muscle trigger points can be formed several ways:

• Repetitive overuse injury
• Habitual poor posture
• Direct injury
• Sustained heavy lifting
• Regular muscle tension and clenching as shown in the image to the right
• Prolonged inactivity

Groups at Risk for Myofascial Pain

While no single cause of myofascial pain has been determined, the known potential sources of myofascial pain points to groups at higher risk of experiencing myofascial pain syndrome:

• Women: Myofascial trigger points are more likely to be active in women than in men—55 percent of women have latent trigger points compared to 45 percent in men.
• Middle-age adults: Chronic myofascial pain most frequently develops during middle age. At younger ages, it’s believed that muscles are better able to cope with the strain of stress and overuse.
• Injured: Injury, trauma or illness increases the odds of developing or activating myofascial trigger points.
• Stressed: An individual may aggravate a myofascial trigger point as a result of stress or anxiety that leads to increased muscle tension.
• Inactive: A sedentary lifestyle or significant time spent in poor posture, such as at a desk, can weaken and strain muscles, making the occurrence of a myofascial trigger point more likely.