Electromyographic studies of tension

Electromyographic investigation of hypnotic arm levitation: differences between voluntary arm elevation and involuntary arm levitation

Thirty-three volunteers were randomly exposed to 3 conditions: hypnotic arm levitation, holding up the arm voluntarily without hypnosis, and imagined arm lifting without hypnosis. Trapezius, deltoid, extensor digitorum, flexor digitorum profundus, biceps brachii, and triceps brachii muscles were measured. Strain and muscle activity during lifting and holding up the right arm for 3 minutes were used as dependent variables. During hypnotic arm levitation, the total muscle activity was lower than during holding it up voluntarily (p < .01); the activity in the deltoid was 27% lower (p < .001). Without hypnosis, the muscle activity showed a positive correlation with strain. However, there was no such correlation in the hypnotic condition. Apparently, it is possible to reduce strain and to objectively measure muscle activity in an uplifted arm through hypnotic arm levitation.

Electromyographic (EMG) feedback in chronic musculoskeletal pain: a controlled trial

The literature regarding the application of EMG feedback training in musculoskeletal pain disorders is reviewed. A within-subject control trial of EMG feedback using a counterbalanced design in patients with chronic musculoskeletal pain is reported here. Eighteen subjects (12 females and 6 males) were studied in terms of subjective reports of pain and EMG activity measurement under standardised conditions. Both EMG feedback and a control condition were active in reducing subjective pain levels, which increased during a waiting list conditions in certain sequences. EMG activity declined during both EMG feedback and control conditions but only EMG feedback resulted in an orderly reduction in EMG baseline measurements with a highly significant linear trend when presented before the control condition in sequence. A significant correlation between subjective pain levels and surface EMG activity was found. These data suggest that EMG feedback is superior to a control condition in training muscle relaxation but not in reducing subjective pain levels despite a high correlation between these two parameters. Non-specific factors may well affect pain scores and further research is required before the specific biofeedback training effect can be accepted as superior to its non-specific effects in reducing subjective pain.

Writer's cramp--a habit for reversal?

Four patients with writer's cramp were treated by nurse-therapists who used a combination of habit reversal, in vivo exposure and re-education. All four resumed normal writing activities after an average of four sessions. At follow-up 2-6 yr later, only one had relapsed, and she improved after further sessions. The brevity and simplicity of this method recommend it in the treatment of writer's cramp.

An operant approach to the treatment of writer's cramp

A theoretical model of writer's cramp is presented. In addition to the original emotional arousal and subsequent conditioned stimuli inherent in a classical conditioning paradigm, this model stresses the role of operant behaviors in the maintenance of the disorder. The immediate consequences of the actual cramp and subsequent escape behaviors are emphasized. An extinction procedure consisting of response-cost and response-prevention measures is tested using an A-B-A-B design. Two patients totally unable to write, were able to increase cramp latency and were gradually retrained to write. Follow-up assessments at 6, 9 and 12 months confirmed the treatment gains.

Relaxation

The relaxed state, to me, is simply the state of being mentally and physically at ease. This does not necessarily mean a passive state, in a quiet place, day-dreaming. It could mean an active state where the individual is working or playing in the day-to-day environment. To achieve this relaxed state the aim is to regulate the amount of stress so it does not exceed a determined level. Above this level, stress becomes counterproductive. We aim for the level of stress that is optimal for each individual at a particular time, performing a particular task. At this level the individual may be active or passive and still be relaxed.

Subjective definitions of tension

To examine the type of proprioceptive information which subjects include in the definition of tension, 52 subjects were asked to indicate the location of where they felt tension while engaging in a simple motor task. Responses indicated that tendon stretch, muscle tension, and other cues are utilized in the subject's definition of tension.