As massage therapy gains popularity as one of the most commonly, used modalities among those offered in complementary and alternative medicine, more research is addressing the physiological effects and mechanisms of massage.
This month’s Massage Therapy Foundation research synopsis reviews an intriguing study out of Umea University, in Sweden, that evaluated the physiological effects of touch massage and was published in the journal, Autonomic Neuroscience: Basic and Clinical.
Like other massage modalities, touch massage is provided to decrease stress, anxiety and pain. Often massage therapists observe decreases in blood pressure, heart rate, and respiration. These observations suggest massage modalities influence the autonomic nervous system and alter an individual’s stress response. The autonomic nervous system is comprised of sympathetic and parasympathetic activity. It controls involuntary bodily functions, such as breathing and the heartbeat. Simply put these two synergistic components act as internal stress (sympathetic) and relaxation (parasympathetic) response systems, which work to maintain autonomic balance. The autonomic nervous system and stress response mechanisms have received considerable attention for explaining a physiological mechanism of massage. Lindgren and colleagues tackled the arduous task of evaluating the physiological effects of touch massage on stress responses in 22 healthy volunteers using a battery of bio-markers to identify autonomic nervous system responses.
Lindgren and colleagues used a crossover design method to conduct this study. In a crossover design, each participant is in both groups (treatment and control). At two separate occasions, each individual either receives the treatment of touch massage or rests in the supine position as a control. Using this method, participants can function as their own comparison with and without the treatment. Though crossover design has many advantages, like requiring smaller sample sizes, the disadvantage of crossover design methods is the carryover effect, where the treatment has lingering effects. If there were a strong carryover effect, we would expect to see the participants who receive treatment first having a different baseline when they return for the control session. However, there were no significant differences between massage first and rest first in the baseline measures taken immediately before the second session, so carryover effects should not influence these results.
Participants received touch massage on their hands and feet, which “consisted of stroking movements on the ventral and dorsal side of hands and feet along with circular movements on each finger and toe. Touch massage was performed for 80 min in the following order: 20 min each on the left hand, the right hand, the right foot, and the left foot.” Participants in the control group rested in the same setting. Outcomes measures included heart rate and heart rate variability (the variation in time between heart beats), cortisol stress hormone levels from saliva, blood glucose, and serum insulin. Data were collected before, during, and after touch massage or rest session.
The main finding in this study for Lindgren and colleagues was, “After 5 minutes of touch massage there was a significant decrease in heart rate lasting for 65 min, indicating reduced stress response.” Though findings suggested significant changes across several measures, “the only significant differences between the groups were the decreases in heart rate after 45 minutes and in the HF component [high frequency domain of heart rate variability] after 5 minutes.” Group differences between treatment and control groups are typically the focus of studies such as this one, because these differences measure the effect resulting from the treatment. Though there were no significant differences between groups in levels of cortisol, glucose, and insulin, “Saliva cortisol and insulin levels decreased significantly after intervention, while the serum glucose level remained stable. A similar pattern, although less prominent was observed in the control group.” The findings from this study suggest, “Touch massage reduces the heart rate by decreasing sympathetic nervous activity and evoking a compensatory decreased parasympathetic nervous activity in order to maintain autonomic balance.” These findings suggest that after receiving touch massage the participants experienced a biological relaxation response – producing the experience of stress reduction.
As with all research, this study identified limitations to interpreting the findings of this study. First, “calm music” was played during the sessions, which could have had an effect; however, music was used in both groups, therefore touch massage served as the single outcome. Second, as with most massage studies the interpersonal interaction between the therapist and recipient could have affected the treatment. We cannot eliminate the effects of this interaction especially since there was no “sham massage” or “therapeutic touch” group included as a level in between treatment and control. One other potential limitation of the study is that the authors reported that five participants’ heart rate and heart rate variability data were excluded due to arrhythmias. Given the already small sample size of less than two dozen individuals, decreasing the sample size by almost 25% for these data points could impact the ability to interpret and generalize these data findings. Further, it is possible that the trend observed of a greater decrease in cortisol following touch massage than following quiet rest and insulin level in this study could prove to be significant with larger sample sizes in future studies. Larger randomized clinical trials will provide evidence for generalizable findings to inform consumers about the effects and physiological mechanisms of touch massage.
This study provides evidence that supports one of the most popular theories for explaining the relaxing effects of massage therapy. Specifically, Lindgren and colleagues found that touch massage significantly reduces cortisol, although not significantly more so than quiet rest, and that massage significantly lowers heart rate. The findings of this study warrant future research to evaluate these physiological mechanisms in larger controlled clinical trials and with more diverse populations. But what does this mean for providers and touch massage recipients? Whether in a non-clinical or clinical setting touch massage can reduce stress for clients and patients. Though this is not likely new information to many providers, as observations of stress reduction are commonplace in the massage setting, Lindgren and colleagues have provided evidence to substantiate these observations, which support incorporating touch massage in individuals’ wellness and healthcare plans to facilitate stress reduction and promote personal health.
Source: Lindgren L, Rundgren S, Winsö O, Lehtipalo S, Wiklund U, Karlsson M, Stenlund H, Jacobsson C, Brulin C. Physiological responses to touch massage in healthy volunteers. Autonomic Neuroscience: Basic and Clinical. 2010; 158: 105-110.