Pain quality description is different between fascia and muscle pain

How we describe pain is important and can be a reliable parameter to characterize both acute and chronic pain. A study from Germany published in Pain Reports studied if verbal descriptors can discriminate between deep muscle pain, overlying fascia, or skin pain.

Sixteen healthy volunteers participated in the study where electrical stimulation was used to excite a broad spectrum of nociceptive primary afferents innervating the various tissues. The 24-item Pain Perception Scale was used to determine the quality of the induced pain.

The study found that all participants experienced pain during single electrical pulse or high-frequency stimulation of muscle or fascia. The pain scores were not significantly different between muscle and fascia pain. However, three types of pain can be distinguished: superficial thermal (“heat pain” identified by the items “burning,” “scalding,” and “hot”), superficial mechanical (“sharp pain” identified by the items “cutting,” “tearing,” and “stinging”), and “deep pain” (“beating,” “throbbing,” and “pounding”).

The “deep pain” factor was more pronounced for muscle than fascia, whereas fascia exhibited a significantly more superficial pain quality (“heat pain” and “sharp pain).

The differences in sensory descriptor patterns between muscle and fascia may potentially guide treatment towards muscle or fascia in low back pain. However, the similarity pain description between fascia and skin, both including the terms “burning” and “stinging,” opens the possibility that neuropathic back pain (when the dorsal ramus of the spinal nerve is affected) may be confused with the low back pain of fascia origin.