M Harvey's research while affiliated with San Diego State University and other places

Citations

... In one study, trigger point activity was shown to increase with both expressed and inhibited anger, with significant correlation with the latter in particular. 141 This may be due to muscle guarding 141 or to sympathetic neurological involvement at muscle spindles (capsular sensory receptors embedded in muscle bellies) 142 seen in pharmacological studies showing decreased electromyographic activity in the trigger point with sympathetic neuron blockers but not with 143 Other studies showed that recalling emotional events increased trigger point activation 144 while relaxation techniques did the opposite. 145,146 Ties were later found between individuals with internalizing traits (high worry, fear of criticism, low assertiveness) and feeling more pain in trigger points than individuals without these traits. ...