According to psychic researcher James H. Hyslop, "the interpretation by the operator of unconscious muscular movements in the subject experimented on." As no paranormal perception is involved in the interpretation, psychical research is not specifically concerned in muscle reading, although the special sensitivities involved may have some relevance to the mechanisms of paranormal cognition. Some have suggested that what has been interpreted as telepathy may in fact be conscious or unconscious muscle reading.
Dessoir, Max. "Experiments in Muscle Reading and Thought-Transference." Proceedings of the Society for Psychical Research 4, 10 (1886-87).
Sugden, E. H. "Note on Muscle Reading." Proceedings of the Society for Psychical Research 1, 4 (1882-83).