La. Rokicki et al., CHANGE MECHANISMS ASSOCIATED WITH COMBINED RELAXATION EMG BIOFEEDBACKTRAINING FOR CHRONIC TENSION HEADACHE/, Applied psychophysiology and biofeedback, 22(1), 1997, pp. 21-41
Therapeutic mechanisms hypothesized to underlie improvements in tensio
n headache activity achieved with combined relaxation and electromyogr
aphic (EMG) biofeedback therapy were examined. These therapeutic mecha
nisms included (1) changes in EMG activity in frontal and trapezii mus
cles, (2) changes in central pain modulation as indexed by the duratio
n of the second exteroceptive silent period (ES2), and (3) changes in
headache locus of control and self-efficacy. Forty-four young adults w
ith chronic tension-type headaches were assigned either to six session
s of relaxation and EMG biofeedback training (N = 30) or to an assessm
ent only control group (N = 14) that required three assessment session
s. Measures of self-efficacy and locus of control were collected at pr
e-and posttreatment, and ES2 was evaluated at the beginning and end of
the first, third, and last session. EMG was monitored before, during,
and following training trials. Relaxation/EMG biofeedback training ef
fectively reduced headache activity: 51.7% of subjects who received re
laxation/biofeedback therapy recorded at least a 50% reduction in head
ache activity following treatment, while controls failed to improve on
any measure. Improvements in headache activity in treated subjects we
re correlated with increases in self-efficacy induced by biofeedback t
raining but not with changes in EMG activity or in ES2 durations. Thes
e results provide additional support for the hypothesis that cognitive
changes underlie the effectiveness of relaxation and biofeedback ther
apies, at least in young adult tension-type headache sufferers.