Objectives: The objective of the present study was to test massage applied with an automated massage chair on the back muscles with regard to the effects on the tension of other muscles or on the neurovegetative tone, and to compare three different automated massage techniques.
Methods: Ten healthy volunteers participated in the study. The experiment consisted of an initial 5-minute period of relaxation without massage, and 5-minute periods of three different massage programs (roll-stretch massage, shiatsu massage, and beat massage). Subjects were randomized as to the presentation order. The following physiologic data were collected: frontalis and gastrocnemius electromyogram (EMG) activity, skin conductance, and peripheral skin temperature. Judgments of valence and arousal were registered using the pencil and- paper version of the five-point Self-Assessment Manikin.
Results: Roll-stretch and shiatsu massage were rated by participants as more pleasant than the relaxation period without massage or the beat massage. Whereas the four conditions were similar with regard to the mean frontal EMG values (reflecting primarily affective states), they differed regarding the gastrocnemius EMG (relating more to a general level of tension), roll-stretch massage, and shiatsu massage, resulting in less muscle tension than the control condition. Shiatsu massage was associated with significantly lower skin conductance than the control condition, whereas beat massage increased it significantly. A significant increase of skin temperature was found during the roll-stretch massage compared to the no-massage condition.
Conclusions: Automated roll-stretch massage and shiatsu massage applied on the back can rapidly induce measurable relaxation in distant muscles not directly massaged, and is accompanied by signs of neurovegetative calming. Back massage applied by an automated massage chair may be an efficient and inexpensive general relaxation approach, and is especially interesting for patients who dislike to be touched.