Contributed by Jolie Haun and Derek Austin

Why does massage make sore muscles feel better? How does massage promote healing? What are the biological mechanisms of massage therapy? These are questions that clients, patients, practitioners and researchers ask all around the world and have been considered since the days of Hippocrates. Massage is a therapeutic modality commonly used to reduce muscular pain and promote rehabilitation. However exactly how massage affects cellular function remains unknown. Yet, still today, as massage therapy continues to remain a popular healing method and a clinically therapeutic modality, science seeks to understand the biological mechanisms by which massage therapy creates therapeutic effects.

The Massage Therapy Foundation is always on the hunt for new research to provide evidence about the bio-mechanisms of massage – inspiring the review of a study by Crane and colleagues published in Science Translational Medicine.

Musculoskeletal problems impact daily function and quality of life, so it is important to validate treatments such as massage therapy, to demonstrate the bio-mechanisms of massage therapy in promoting recovery, while reducing inflammation and muscular pain. The increase in physician and chiropractic referrals for massage for musculoskeletal injuries indicates a shift in practice toward the use of massage therapy as a complementary modality to conventional care. As massage gains popularity as an adjunctive therapy, it must be validated as a clinically effective treatment that can be medically billed for and reimbursed in the healthcare setting. Validation of the biological mechanisms of massage is the fundamental basis for advancing the science and practice of massage therapy.

Crane and colleagues seek to contribute to the field of science through innovative research which used methods that provide data, at a bio-molecular level, that describes the effects massage therapy has on muscular-skeletal tissue. The aim of this study was to investigate the pain relieving effects of massage therapy with a sample of 11 men. Each participant was asked to exercise to the point of exhaustion to create exercise-induced muscle damage to their thighs. Immediately following the exercise, participants recovered for 10 minutes. Massage oil was lightly applied by a registered massage therapist to both quadriceps while the participant lay in the supine position. To assess the effects of massage, the research team administered either massage treatment or no treatment to the quadriceps of each participant; such that, one leg was randomized to receive the massage treatment for 10 minutes. The treatment included the use of three types of soft tissue manipulations: (1) two minutes of effleurage, using moderate pressure at the beginning and end of the treatment; (2) three minutes of petrissage; and (3) three minutes of slow muscle stripping. After massage, the subjects rested for 10 minutes. Unique to this study, muscle biopsies were acquired from the participants’ quadriceps (vastus lateralis) at three time-points: before treatment (also known as baseline), right after massage treatment, and after a 2.5-hour recovery period.

Findings indicated massage therapy reduced inflammation through production of inflammatory cytokines; and promoted mitochondrial biogenesis, promoting enhanced recovery. However, findings did not support the popular notion that massage therapy clears lactic acid from muscle tissue; nor did glycogen levels change. In scientific terms, Crane and colleagues suggest the massage treatment.

Activated the mechanotransduction signaling pathways focal adhesion kinase (FAK) and extracellular signal–regulated kinase 1/2 (ERK1/2), potentiated mitochondrial biogenesis signaling [nuclear peroxisome proliferator–activated receptor g coactivator 1a (PGC-1a)], and mitigated the rise in nuclear factor kB (NFkB) (p65) nuclear accumulation…despite having no effect on muscle metabolites (glycogen, lactate), massage attenuated the production of the inflammatory cytokines tumor necrosis factor–a (TNF-a) and interleukin-6 (IL-6) and reduced heat shock protein 27 (HSP27) phosphorylation, thereby mitigating cellular stress resulting from myofiber injury.

These study findings provide evidence that manipulative therapies may be justifiable in medical practice. According to Crane and colleagues, the effects of massage are akin to the same mechanism as conventional drugs, such as non-steroidal anti-inflammatory drugs (NSAIDs). Findings such as these, are the basis for providing patients and clients the option of massage therapy opposed to conventional drug-based therapies (e.g. NSAIDS).

Though these study findings provide much promise for advancing the science and practice of massage therapy, some study limitations that should be noted. The study sample size was small, involving only 11 males. A larger sample size using females and males would provide more power and rigor to data findings. Another limitation of this design is that it was impossible to blind the therapists and the patients to the treatments, however the research team was blinded to which leg received treatment; this was known only to the massage therapists. Though these study limitations cannot be denied, the strengths of this study outweigh limitations. The use of biopsied tissue data is a rare case in massage therapy research, but has proven critical in gaining insights to the biological mechanisms of this muscular-skeletal based adjunctive therapy. It is recommended that future research investigate additional post-translational signaling pathways influenced by massage therapy.

Crane and colleagues have provided much needed data about the biological mechanisms of how massage therapy promotes healing. If you practice massage to treat sore, tired muscles you can refer patients and clients to resources such as this article to support massage therapy as an evidence-based practice. The next time someone asks how massage therapy works, you can highlight these findings which suggest massage therapy effects inflammation and enhanced mitochondrial biogenesis; and dispel beliefs about milking muscles of lactic acid.

If you are interested in learning more about the evidence supporting the use of massage therapy in clinical practice with different populations, you can review the Massage Therapy Foundation article archives, read accepted abstracts or search Pub Med for massage therapy studies.

Source

• Crane JD, Ogborn DI, Cupido C, Melov S, Hubbard A, Bourgeois JM, Tarnopolsky MA. Massage therapy attenuates inflammatory signaling after exercise-induced muscle damage. Science Translational Medicine. 2012 Feb 1;4(119):119ra13.

For more information about the Massage Therapy Foundation, visit www.massagetherapyfoundation.org.