Not what they seem
After years of practice, I can easily find your infraspinatus muscle. In the dark, in about three seconds. Through a thick towel. However, massage and manual therapists often fool themselves into thinking they are feeling things under their hands that are not actually there, or things that might be there but cannot possibly be detected with any reliability. This is palpatory pareidolia: illusions in the sense of touch.
Palpatory Pareidolia & Diagnosis by Touch: Tactile illusions, wishful thinking, and the belief in advanced diagnostic palpation skills in massage and other touchy health careI’ve written about this before, but this is a topic “reboot,” with content combined from a few early drafts and whipped into shape for a permanent article: