Abstract
Purpose
To confirm the effects of relaxing back massages on early healthy postpartum mothers by using autonomic nervous system activity and subjective self-ratings derived using a questionnaire on relaxation.
Method
We randomly assigned 45 healthy mothers who had delivered 3 days previously to 2 groups: intervention group (22 mothers who received 20-min back massages with odorless oil) and control group (23 mothers who did not receive back massages but were instructed to rest in bed in the supine position). A quiet climate-controlled room was used. Autonomic nervous system activity was assessed using the heart rate, RR-interval variability, LF/HF (low frequency/high frequency) ratio, and HF, all of which were measured using LRR-03 (GMS). The data of RR-interval variability and subjective relaxation scores were used to determine the effects of back massages.
Result
The heart rate and LF/HF ratio decreased, while the HF value and relaxation score increased in both the groups. Although the results derived using the RR-interval variability data and relaxation scores indicate that back massages had a relaxing effect, no significant differences were detected between the groups. In some mothers of the intervention group, unique and varying patterns of heart rate, HF, and LF/HF ratio were observed because of changes in their autonomic nervous system activity.
Conclusion
Back massages seemed to predominantly activate parasympathetic rather than sympathetic nerves. They also apparently produced a feeling of relaxation. However, the results did not validate any substantial effect of the relaxing back massages on postpartum mothers because of the absence of a statistically significant difference between the 2 groups. We estimate that this result is attributable to the following factors: frequent resting in bed in the supine position, sleeping during the intervention, inter-individual differences in autonomic nervous system activity, and time since delivery.
