It is a natural tendency to rub the injured area when someone has overexerted a muscle. This stress on the muscle tissue and related injuries is known as “exertion induced muscle injury.” Individuals often seek massage therapy to relieve the soreness in these muscles. For example, this is a basic concept of sports massage, as athletes have a tendency to over exert themselves and often experience much relief from receiving massage therapy.
The Massage Therapy Foundation and the massage therapy profession have a great deal of interest in understanding the mechanisms of muscular injury phenomena, and the role of massage therapy in improving function and recovery. In fact, the Foundation recently supported the work of a group of researchers, Franklin and colleagues, to examine the role of vascular endothelial function in exercise-induced muscle injury and recovery supported by massage therapy. The purpose of this study was to: investigate the mechanisms of systemic endothelial dysfunction of the brachial artery, which develops after exercise-induced muscle injury of the lower extremities; and determine if treatment of the lower extremities with massage therapy reduces endothelial dysfunction. The authors hypothesized that a massage therapy treatment performed after exposure to exercise-induced muscle injury would protect against impaired endothelial function.
Franklin and colleagues conducted a randomized, blinded trial with 36 sedentary young adults in a clinical research setting at an academic medical center and laboratory. Each participant was randomly assigned to one of three groups: treatment following exposure to 75 exercise-induced muscle injury (exercise-induced muscle injury + massage therapy); a control intervention of exercise-induced muscle injury without MT treatment (exercise-induced muscle injury only); or a 76 control intervention of massage therapy treatment without exercise-induced muscle injury (massage therapy only). The exercise-induced muscle injury was induced by a single bout of bi-lateral leg press exercise.
The massage therapy protocol was provided by one licensed and certified massage therapist. The treatment included a 30-minute bilateral lower extremity (legs) massage using Swedish techniques varying in depth from superficial to deep.
Participants were screened in an initial visit. Approximately one week following the initial screening, participants who met all inclusion criteria returned for baseline assessment of endothelial function. Participants provided data at five time points before (baseline) and after (90 minutes, 24 hours, 48 hours and 72 hours) the intervention. Several measures were taken, all after a 12-hour fast. The primary measures, determined by ultrasound, were brachial artery flow-mediated dilation and Nitroglycerin-induced dilation.
Findings indicate brachial (upper extremity) flow-mediated dilation increased from baseline in the exercise-induced muscle injury + massage therapy group and the massage therapy only group at 90 minutes remaining elevated until 72 hours post treatment. In the exercise-induced muscle injury only group, flow-mediated dilation was reduced from baseline at 24 and 48 hours returning to baseline after 72 hours.
Interpreting the Findings
Results indicate that massage therapy has systemic effects on endothelial function; such that massage therapy lessens impairment of upper extremity endothelial function resulting from lower extremity exercise-induced muscle injury in sedentary young adults. Dilations due to Nitroglycerin were similar over time. Authors suggest this is the first study to determine that massage therapy protects against reduced upper extremity endothelial function following lower extremity exertion.
The primary finding of this study is that massage therapy reduces impairment of brachial artery flow-mediated dilation resulting from exercise-induced muscle injury. The authors also reported the unexpected finding that lower extremity massage enhances brachial artery flow-mediated dilation even in the absence of exercise-induced muscle injury.
Franklin and colleagues mentioned several study limitations including the possible confounding of results by the absence of a true control group; the inability to test endothelium independent dilation to nitroglycerin before exercise-induced muscle injury and/or massage therapy because of the residual vasodilator effects of this compound on blood pressure; due to the small sample size this study was also unable to assess gender or racial/ethnic-specific effects; and differences in BMI may confound the effects of massage on flow-mediated dilation.
The authors indicated future research would benefit from a no intervention control group and larger sample sizes to validate these findings, as well as allow for sub-group analyses.
The results of this research suggest that exercise-induced muscle injury impairs systemic endothelial function; and massage therapy enhances endothelial function in both the presence and absence of muscle injury. These study results contribute to understanding how massage therapy promotes faster recovery from exercise-induced muscle injury and may have broader implications for the clinical use of massage therapy, especially in the context of endothelial dysfunction.
From a clinical perspective, massage therapy is a widely used. Annually, millions of Americans receive massage therapy for health reasons such as pain relief, injury recovery and rehabilitation, yet to date research provides little evidence for the effects of massage on blood flow. Findings in the current study indicate that a single massage treatment improves brachial artery endothelium-dependent flow-mediated dilation for up to 48 hours.
How do these findings apply to clinical practice? Franklin and colleagues suggest that since flow-mediated dilation correlates with cardiovascular risk, their study findings may support the use of massage therapy for reducing exercise-induced muscle injury and post-exercise hypo-perfusion in at risk populations, such as individuals with heart disease who are engaged in intense exercise regimens. As the field of massage continues to expand its application to the medical field, Franklin and colleagues also suggest massage-induced improvements in endothelial function may help to protect against vascular responses to other physical stressors such as acute hypertension, hypoxemia and wound healing.
Massage therapists commonly observe and state that part of the benefit of massage therapy is increased circulation, which promotes healing and wellness. The work of Franklin and colleagues make an empirical contribution to the growing body of evidence that supports these clinical observations and claims.
If you would like to learn more about the evidence based research that supports the benefits and mechanisms of massage therapy, you can review the Massage Therapy Foundation article archives, read accepted MTF Research Grant abstracts or search Pub Med. Also, take the opportunity to boost your research knowledge by registering for an MTF Basics of Literacy course. You can explore the basics of incorporating principles of research literacy into your practice or school curriculum at your own pace.
- Franklin NC, Ali MM, Robinson AT, Norkeviciute E, Phillips SA. (2014) Massage Therapy Restores Peripheral Vascular Function following Exertion. Archives of Physical Medicine and Rehabilitation.