EMG scanning: Normative data

Surface EMG was recorded from both right and left aspects of 18 muscle groups for the purpose of establishing a data base of normative EMG levels. A scanning electrode permitted easy and rapid EMG measurement from 52 male and 51 female college students, both sitting and standing. Several a posteriori analyses of variance revealed sex differences in the masseter, occipital, posterior cervical, upper trapezius, latissimus dorsi, and anterior tibialis. Similarly, there were side differences for the anterior temporalis, occipitalis, splenius capitus, trapezius, paraspinalis, and soleus. The analyses also revealed interactions among sex, position, and side for various measures on the trapezius. The data show that females tend to muscle brace more than males in the upper extremities. The study provides data for normative comparisons and helps to plan and interpret future EMG studies.     

Temperature self-regulation and relaxation with migraine patients and normals

Ten migraine headache subjects and 10 non-migraine subjects were divided equally into two groups: a progressive relaxation group and a finger temperature biofeedback group. Finger temperature, temporal artery pulse amplitude and forehead blood flow were monitored for all subjects during two baseline and six treatment sessions.

The biofeedback group achieved greater (albeit low magnitude) increases in finger temperature than the relaxation group, but no improvement in headache activity was obtained. However the relaxation group improved significantly in terms of headache intensity.

There was no significant difference in the ability to achieve finger temperature control, nor in stability point temperatures, between the migraine and non-migraine subjects.

No systematic relationship was found between finger temperature, forehead blood volume and temporal artery pulse amplitude. Possible mechanisms of the therapeutic effects of finger temperature training are examined in the light of these results.     

Physiologic and self-report comparisons between tension headache sufferers and nonheadache controls

Tension headache sufferers and nonheadache controls were compared with respect to (1) frontal EMG during both baseline and presentation of an imagined stressor, (2) trait anxiety, (3) locus of control expectancies for health related behaviors, and (4) exposure to stressful life events. Tension headache sufferers displayed higher resting muscle tension levels than did nonheadache controls. However, both groups responded similarly to the imagined stress stimulus and displayed significant muscle tension elevations of similar magnitude. While tension headache sufferers reported higher levels of trait anxiety, no differences were found between the two groups for locus of control expectancies and exposure to stressful life events. The diagnostic and treatment implications of these findings are discussed.     

BIOFEEDBACK AND RATIONAL-EMOTIVE THERAPY IN THE MANAGEMENT OF MIGRAINE HEADACHE

Twenty-four migraine patients were randomly assigned to one of four conditions: (a) self-monitoring of headache activity (waiting list), (b) frontalis EMG biofeedback, (c) digit temperature biofeedback, and (d) digit temperature biofeedback plus Rational-Emotive Therapy (RET). Bidirectional control over the target physiological response was assessed through a reversal design in each session. Following at least a four-week baseline, the three biofeedback groups received 8 to 10, 30-minute sessions of bidirectional biofeedback training, scheduled twice a week. Subjects in the combined digit temperature biofeedback plus RET group received three 40-minute sessions of RET as an addition to the third, fifth, and seventh biofeedback sessions. Records of daily home practice were kept throughout treatment and three-month followup. Subjects on the waiting list monitored headaches for at least five months, corresponding to “baseline”, “treatment”, and three-month followup. Digit temperature biofeedback alone and in conjunction with RET did not prove to be more effective than the control conditions. All the EMG subjects reduced headache activity to two-thirds or less of the baseline level by the third month of followup. Bidirectional digit temperature performance did not improve with training, was demonstrated in only 33% of the biofeedback sessions, was not maintained over time, and was unrelated to improvement in headache activity. EMG subjects reported biofeedback performance to be an easier task and met the performance criterion on 85% of the sessions. The frequency of home practice contributed over 55% of the variance in retrospective estimates of headache improvement but was not related to changes in daily records of headache activity.     

Electrode placement,EMG feedback,and relaxation for tension headaches

Fifteen tension headache subjects were allocated to one of three groups: direct EMG feedback (from a site corresponding to the source of pain), indirect EMG feedback (from a site not corresponding to the source of the pain) and relaxation instructions. There were two base-line, six treatment and one post-treatment sessions. No significant differences were found between base-line and post-treatment EMG levels, for any of the groups; however, some significant reductions in levels were obtained within sessions. EMG levels recorded during headache attacks did not differ significantly from levels recorded during base-line. Frequency and intensity of headaches were significantly reduced, particularly in the relaxation group. At follow-up this improvement was maintained for subjects with forehead pain, but differences between the groups had disappeared.     

A comparison of psychological and pharmacological treatment of pediatric migraine

A comparison was carried out of the efficacy of psychological and drug treatments for children with migraine. Forty-three children aged between 8 and 16 years (mean age: 11.3 years) who suffered from migraine received either progressive relaxation or cephalic vasomotor feedback, both with stress management training, or metoprolol, a beta-blocker. Psychological treatment was administered in ten sessions lasting six weeks and the drug treatment lasted ten weeks. Relaxation and stress management training reduced the headache index (frequency×intensity of headache episodes), more effectively than metoprolol with cephalic vasomotor feedback and stress management training in between. An overall improvement over time was found with regard to frequency and intensity of headache episodes and analgesics intake. When comparing pre- to post-treatment data, children treated with relaxation training improved significantly in headache frequency and intensity, whereas those treated with cephalic vasomotor feedback improved significantly in headache frequency and duration as well as mood. The clinical improvement was stable at an 8-months follow-up.     

Long-term follow-up of migraine treatment: do the effects remain up to six years?

Fifty migraine subjects (constituting 79% of the originally treated sample) participated in a follow-up study to 6 yr after the end of treatment. Subjects had been treated with different forms of biofeedback methods (skin temperature, BVP of the temporal artery) and applied relaxation training. The assessment included 4 weeks of continuous self-monitoring of headache activity and medication usage, as well as a retrospective self-rating scale. The main results indicated that, on a group basis, headache reductions achieved at the end of treatment persisted for up to 6 yr, and were indeed enhanced during the follow-up period.     

Facial expressions of pain in muscle-contraction headache patients

Using a judgment and component analysis of facial actions, 14 muscle-contraction headache (MCH) patients were videotaped in headache and nonheadache states. In addition, patients were also required to undergo a resting physiological assessment (frontalis electromyography, temporal blood volume pulse, and heart rate), reaction-time task, and complete self-report measures of pain state and mood. Headache and nonheadache state of MCH patients were reliably identified by 20 observers. Characteristics of facial expressions that occurred most frequently in the headache state included furrowed eyebrows, closed eyes, slow eye blinks, lip pursuing, facial grimacing, and flat facial affect. Headache state was also associated with increased latency to respond to an auditory tone and mood disturbances, but no differences in baseline physiological activity were observed. Our findings provide support for the utility and clinical relevance of judgment and component analysis of facial actions in MCH patients.     

MODIFICATION OF COMBINED MIGRAINE-MUSCLE CONTRACTION HEADACHES USING BVP AND EMG FEEDBACK

The effect of blood volume pulse (BVP) and frontalis muscle action potential (EMG) feedback on control of vasoconstriction of the temporal artery and frontalis muscle activity in combined migraine-muscle tension subjects was investigated in a multiple baseline design (across subjects and responses). The data indicated: (a) both subjects obtained an ability to control BVP during BVP feedback and EMG during EMG feedback; (b) there were decreases in frequency of migraine headaches during BVP feedback and decreases in muscle contraction headaches during EMG feedback. The results of this study supported the theoretical explanation of two pain mechanisms involved in combined muscle contraction-migraine headaches as well as the effectiveness of biofeedback procedures that target directly the specific pain mechanism in the elimination of the two types of head pain.     

Seating position and length of utterance of preschoolers with cerebral palsy

This study investigated the effects of semireclining and upright positions on production of utterances of increasing length by 10 physically typical preschoolers and 10 children with cerebral palsy. Sentences of 3, 7, and 10 syllables were imitated on one breath using the Respitrace to gather kinematic data of chest wall use. Analysis indicated that the reclining position led to 83% productions on one breath, while 95% could be produced on one breath in the upright position. During the longer 7- and 10-syllable utterances, children with cerebral palsy successfully imitated 48% and 18% of these utterances, while the control group performed 83% and 35% correctly for the 7- and 10-syllable tasks, respectively.     

Sequential comparisons of relaxation training and biofeedback in the treatment of three kinds of chronic headache or,the machines may be necessary some time of the time

Two studies are reported in which patients with chronic headache, who did not improve significantly as a result of a 10-session, 8-week relaxation training program, were subsequently treated with biofeedback. For the tension headache sufferers, 36% of the relaxation non-responders showed significant improvement with frontal EMG biofeedback training. For those with vascular headaches, 44% of the relaxation non-responders showed significant improvement with thermal biofeedback. Vascular headache patients with combined migraine and tension symptoms did better than those with only migraine. Psychological test scores significantly differentiated successful vs non-successful biofeedback responders.     

Psychophysiological responding as a function of age: The importance of matching

Few studies in the past which have employed psychophysiological measures have controlled for age. We have studied the effects of age on the heart rate, hand surface temperature, cephalic vasomotor response, and frontal electromyographic activity (EMG) of 73 normal individuals who varied in age from 18 to 68 years and were evenly divided into younger, middle, and older age groups. Comparisons were made between groups across eight conditions — baseline, relax body, warm hand, relax facial muscles, mental arithmetic, positive imagery, negative imagery, and cold pressor. Results indicated a direct linear relationship between age and electromyographic activity during relax facial muscles and mental arithmetic conditions. There was also a linear relationship between age and hand surface temperature during stressor conditions. Most important, significant interactions were found for both frontal EMG and heart rate measures with age. Post hoc analyses revealed differences on the frontal EMG levels between younger and older age groups during negative imagery, warm hand, and cold pressor conditions. Heart rate differences were found during positive imagery between the younger age group and the medium age group and during cold pressor between the younger age group and both the medium and the older groups. The implications of these findings are discussed.This research was supported in part by NINCDS Grant NS-15235.     

Expressive timing and interactional synchrony between mothers and infants: cultural similarities, cultural differences, and the immigration experience

The spontaneous vocal interactions of 30 mothers and their 2- to 5-month-old infants from India, France, and the United States were analyzed using an acoustic analysis method. Similarities and differences in vocal interactional patterns were highlighted between the three groups. On the one hand, in the three cultural contexts mother–infant vocal interaction was found to be organized around hierarchical temporal intervals of the same approximate length, had the same balance between regular rhythm and variation (“expressive timing”), and manifested the same coordination between mother and infant vocalization (“interactional synchrony”). On the other hand, the three groups also revealed cultural variability. The Indian mothers had more togetherness with their babies, as indexed by less space between vocal turns and more overlap of mother and baby vocalizations. They also produced a higher ratio of nonverbal to verbal vocalizations. The spontaneous vocal interactions of a group of 30 Indian immigrant dyads were also studied. With respect to culturally variable characteristics, the vocal interaction of immigrant dyads living in the United States showed signs of change in the direction of the host culture. With respect to characteristics shared by all three nonimmigrant groups, the immigrant dyads showed lower levels of expressive timing and interactional synchrony than the nonimmigrant group as a whole.     

Ipsilesional arm reaching movements are not affected by the postural configuration adopted by individuals with stroke

Individuals with stroke present several impairments in the ipsilesional arm reaching movements that can limit the execution of daily living activities. These impairments depend on the side of the brain lesion. The present study aimed to compare the arm reaching movements performed in sitting and standing positions and to examine whether the effects of the adopted posture configuration depend on the side of the brain lesion. Twenty right-handed individuals with stroke (half with right hemiparesis and a half with left hemiparesis) and twenty healthy adults (half used the left arm) reached toward a target displayed on a monitor screen placed in one of three heights (i.e., upper, central, or lower targets). Participants performed the reaches in sitting and standing positions under conditions where the target location was either well-known in advance (certainty condition) or unknown until the movement onset (uncertainty condition). The values of movement onset time, movement time, and constant error were compared across conditions (posture configuration and uncertainty) and groups for each target height. Individuals with stroke were slower and spent more time to start to move than healthy participants, mainly when they reached the superior target in the upright position and under the uncertainty condition. Individuals who have suffered a right stroke were more affected by the task conditions and those who suffered a left stroke showed less accurate reaches. Overall, these results were observed regardless of the adopted posture. The current findings suggested that ipsilesional arm reaching movements are not affected by the postural configuration adopted by individuals with stroke. The central nervous system modulates the reaching movements according to the target position, adopted posture, and the uncertainty in the final target position to be reached.     

Clinical effects of biofeedback treatment in migraine: The relation to achieved self-control and pretreatment predictors

Abstract

Factors contributing to the headache reduction six months after treatment of sixty-three migraine subjects were examined in three different studies. Subjects had originally been treated with either peripheral skin temperature biofeedback, biofeedback for blood-volume-pulse amplitude of the temporal artery, or applied relaxation. In Study 1 it was found that biofeedback subjects who had achieved self-control of the trained physiological parameter had significantly greater headache reductions than “nonlearners”. In Studies 2 and 3, potential predicting factors of clinical effects were studied. Age and whether subjects had achieved self-control emerged as (weak) predictors in different analyses using discriminant analysis. Using “PLS” (partial least squares projections to latent structures) a model emerged which gave a more complex picture, and which might indicate for example that there are different sets of factors which predict success and predict nonsuccess in treatment.     

Social problem‐solving,perceived stress,depression and life‐satisfaction in patients suffering from tension type and migraine headaches

This study aimed at investigating social problem solving, perceived stress, depression, and life‐satisfaction in patients with tension type and migraine headaches. Forty‐nine migraine and 42 tension type headache patients (n = 91) consenting to participate were compared to a total of 49 matched healthy control group. Participants filled in a questionnaire consisting self‐report measures of problem solving, perceived stress, depression and life satisfaction. They were also asked about headache duration, frequency, pain severity, psychiatric treatment and sense of control in one's life. T‐tests, chi‐square, analysis of variance, logistic regression analysis and Pearson product moment correlation coefficient procedures were used to analyze the data. Tension type headache patients reported having had more frequent headaches than the migraine patients but migraine patients reported having had more intense pain than the tension type headache patients. Instances of psychiatric treatment were more common among tension type headache patients than the migraine and the control group. Compared to the healthy controls, headache patients displayed a deficiency in problem solving, higher levels of perceived stress and depression. Levels of problem solving skills in headache patients were related inversely to depression, perceived stress and the number of negative life events but problem solving skills of headache patients was related positively to life‐satisfaction. The findings from this study suggested that cognitive behavioral problem solving therapy or training might be a viable option for reducing levels of stress and depression, and to increase life‐satisfaction in patients suffering from primary headache.     

Effects of scapular retraction/protraction position and scapular elevation on shoulder girdle muscle activity during glenohumeral abduction

According to scapulohumeral rhythm, shoulder abduction is followed through scapular upward rotation to ensure joint mobility and stability. Of interest, the shoulder abduction can be performed holding the scapula in different positions and in association with scapular elevation, with possible effects on shoulder muscle activity. Therefore, the aim of the study was to analyze the activity of relevant shoulder muscles and the activity ratios between the scapulothoracic muscles, during shoulder abduction performed in different combinations of scapular position (neutral, retracted, protracted) and scapular elevation.The electromyographic activity of middle deltoid, serratus anterior, upper, middle and lower fibers of trapezius was recorded during shoulder abduction movements executed holding the scapula in neutral, retracted and protracted position, and subsequently a shoulder elevation movement. The activation of each muscle and the scapulothoracic muscles activity ratios were determined every 15 degrees, from 15° to 120° of abduction.Scapular retraction led to higher activation of the entire trapezius muscle, whereas protraction induced higher upper trapezius, middle deltoid and serratus anterior activity, along with lower activity of middle and lower trapezius. Shoulder elevation led to higher activity of the upper trapezius and middle deltoid. Moreover, it induced lower activation of the serratus anterior and middle and lower trapezius, thus leading to high ratios between the upper trapezius and the other scapulothoracic muscles, especially between 15 and 75 degrees of abduction.This study highlights that shoulder abduction performed with scapular protraction and in combination with scapular elevation leads to increased activity of the middle deltoid and upper trapezius, resulting in imbalances between the scapulothoracic muscles that could hamper the optimal scapulohumeral rhythm. The abduction performed in the aforementioned scapular conditions also induce potential reciprocal inhibition effects between the movers and stabilizers muscles of scapula, suggesting different motor control strategies of integrating a common shoulder movement with various modification of the scapular position.     

Site-specific muscle hyper-reactivity in musicians with occupational upper limb pain.

Fourteen musicians who reported a history of pain in the upper limb associated with the playing of their instruments were compared with a sample of pain-free musicians, matched for age, sex and musical instrument. Four tasks were presented in random order and included neutral, general stressor, personal stressor and pain stressor tasks. Ratings of stressfulness and recordings of skin conductance level confirmed the effectiveness of the experimental manipulations for both subject groups. No differences were found between groups or tasks for frontalis surface electromyograph (EMG) activity. Evidence was found, however, of EMG elevation in flexor and trapezius muscles on the pain side for the pain subjects, in response to the task involving recall of a pain experience. This elevation was not found for the pain-free controls or for other stressor tasks, although some elevation in response to the pain stressor task was found for pain subjects in the trapezius muscles of the non-pain side. The duration of return to baseline of EMG following the pain stressor task was found to be extended in pain subjects for the trapezius, but not for the flexor muscles of the pain side. The findings suggest that site-specific muscle hyper-reactivity may play a role in the development and maintenance of occupational upper limb pain in musicians.     

The relationship between frontalis muscle activity and self-reports of headache pain

The relationship between levels of frontalis muscle activity and self-reports of pain was evaluated in two studies. In Study I frontalis muscle activity and self-reports of pain collected during biofeedback treatment of muscular contraction headache clients were correlated. In Study II frontalis EMG activity was increased and decreased using biofeedback techniques while concurrent reports of headache pain were recorded. The results of Study I indicated a significant relationship between EMG activity and reported headache pain for only two of the five subjects studied. The biofeedback procedures in Study II were associated with reliable increases and decreases in EMG activity. Concordance between EMG and pain reports occurred only during the EMG increase condition. Overall correlations were significant for one of the 2 subjects. The results suggest that EMG activity may not be sufficient to account for pain reports in all chronic headache clients, and variables other than EMG activity may be influencing reports of pain in some patients.     

Anticipatory and compensatory postural adjustments in sitting in children with cerebral palsy

The aim of this study was to examine postural control in children with cerebral palsy performing a bilateral shoulder flexion to grasp a ball from a sitting posture. The participants were 12 typically developing children (control) without cerebral palsy and 12 children with cerebral palsy (CP). We analyzed the effect of ball mass (1 kg and 0.18 kg), postural adjustment (anticipatory, APA, and compensatory, CPA), and groups (control and CP) on the electrical activity of shoulder and trunk muscles with surface electromyography (EMG). Greater mean iEMG was seen in CPA, with heavy ball, and for posterior trunk muscles (p < .05). The children with CP presented the highest EMG and level of co-activation (p < .05). Linear regression indicated a positive relationship between EMG and aging for the control group, whereas that relationship was negative for participants with CP. We suggest that the main postural control strategy in children is based on corrections after the beginning of the movement. The linear relationship between EMG and aging suggests that postural control development is affected by central nervous disease which may lead to an increase in muscle co-activation.