Neck muscle isometric contractions in chronic tension type headache
Cervical muscle co-activation in isometric contractions is enhanced in chronic tension type headache patients
From: Cephalalgia. 2008 Jul;28(7):744-51. Epub 2008 May 5
The purpose of the study was to compare the co-activation of cervical agonist and antagonist muscles between people with chronic tension type headache and healthy controls during brief isometric neck flexion and extension contractions. Nine women with chronic tension type headache and 10 matched controls participated. Surface electromyographic (EMG) signals were detected from the sternocleidomastoid and splenius capitis muscles bilaterally during neck flexion and extension contractions of linearly increasing force from 0% to 60% of the maximum voluntary contraction in 3 s. Sternocleidomastoid and splenius capitis EMG average rectified values were estimated at 10% maximum voluntary contraction force increments. During cervical extension contraction, sternocleidomastoid (i.e. antagonist muscle) average rectified values was greater for patients than for controls in the force range 20-60% maximum voluntary contraction. During cervical flexion, the left splenius capitis (i.e. antagonist muscle) average rectified values was greater for chronic tension type headache patients regardless of the force level. Maximum neck flexion and extension force was lower for the chronic tension type headache patients compared with controls.
In conclusion, women with chronic tension type headache demonstrated greater co-activation of antagonist musculature during cervical extension and flexion contractions compared with healthy women. Increased co-activation of antagonist musculature may reflect reorganization of the motor control strategy in chronic tension type headache patients, potentially leading to muscle overload and increased nociception.
