Effects of voluntary muscle tension increases in tension headache.
D000328:Adult; D006257:Head; D006261:Headache / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction; D009132:Muscles / Q000503:physiopathology; D009334:Neck Muscles / Q000503:physiopathology