An approach to the nature of tension headache.
D000293:Adolescent; D000328:Adult; D000368:Aged; D004576:Electromyography; D005260:Female; D006261:Headache / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction