Premium
Quantitative observations on maximum static work efforts and associated pain of the human masseter muscle
Author(s) -
CHRISTENSEN L. V.
Publication year - 1988
Publication title -
journal of oral rehabilitation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 93
eISSN - 1365-2842
pISSN - 0305-182X
DOI - 10.1111/j.1365-2842.1988.tb00193.x
Subject(s) - isometric exercise , pain tolerance , masseter muscle , intensity (physics) , work (physics) , medicine , electromyography , sensation , physical therapy , threshold of pain , physical medicine and rehabilitation , psychology , anesthesia , dentistry , physics , quantum mechanics , neuroscience , thermodynamics
Summary The single case experimental design was used to study day‐to‐day variations in the onset ( P L ), tolerance ( P T ), and intensity (VAS) of masseter muscle pain. Pain was induced by maximum voluntary teeth clenching, with no artificial feedback‐control of the level of isometric activity, and static work efforts were quantified by cumulative electromyography. A continual effort to produce maximum static work, about 40% increase from baseline work, elicited in 30–40s an initial sensation of muscular pain that had an intensity of about 25% of maximum possible score. A further increase in maximum static work effort, about 60% increase from baseline work, caused in about 2min an intolerable increase in the intensity of muscular pain, about 50% of maximum possible score. Whereas P L showed day‐to‐day variation, P T and the ratio P L : P T did not. Intensity (VAS) scores and maximum static work efforts showed no day‐to‐day variations. Onset ( P L ) and tolerance ( P T ) showed no linear associations with VAS scores, and VAS scores showed no linear associations with maximum static work efforts; if anything, the latter associations tended to resemble a cubic parabola. Two different central neural processes, not associated with maximum static work efforts in a simple linear manner, might have been instrumental in: (i) the establishment of criteria for onset and tolerance of pain, and (ii) the discrimination of variable levels of pain intensity.