How does massage therapy work?

At first glance, the question of how massage therapy works may seem like an easy one to answer, but the answer is not simple.  Massage works via multiple, complex routes in the nervous, endocrine, and immune systems, and is impacted by physical, psychological, and social factors. 

Before addressing how massage therapy works, let’s address some common misconceptions:

  1. Massage increases systemic circulation.  The idea that massage increases circulation is a very popular one and on the surface it might seem to make sense that pressing on the body would move the blood around.  But this idea has no scientific support.  In fact, it’s clear that the opposite is true since both relaxing and lying horizontal for an hour are going to reduce blood flow more than anything other than sleeping.  If one wants to get blood circulating more, this would be better accomplished by simply walking around.  
  2. Massage removes “toxins”.  It’s easy to think that if one feels better after a massage that the massage must have taken out “bad stuff”, especially if one thinks that circulation was increased, but that’s simply not how it works.  Pressing on the body doesn’t squeeze out waste products, and the commonly disparaged lactic acid is definitely not relevant.  All of those feel good effects are driven by the nervous and endocrine systems.  
  3. Massage changes the length of muscle or fascia to create a more balanced structure.  It’s natural to think that a change of posture or increased ROM after massage must be due to changes in the length of muscle or connective tissue, but it’s not possible to change the length of either tissue by pressing on it.  All changes to posture or ROM after a massage are due to changes in the nervous system.  Furthermore, the notion that problems arise from tissue or postural imbalances has no evidence and in fact has been consistently refuted.  The changes clients sometimes experience in posture or ROM are not the cause of them feeling better but rather the effect.  
  4. Relaxing muscle.  Everyone thinks about massage as being about relaxing muscles, but relaxed muscles is just the end result of nervous system changes.  Relaxed muscles have little to no effects on everything else, and in most cases it might subjectively feel like the muscles have relaxed when they haven’t objectively changed at all.  

An important thing to notice here is how all the common misconceptions involved thinking in terms of tissues rather than the nervous system.  Now that we have briefly examined common misconceptions, we can move onto how massage actually works, which is primarily about various aspects of the nervous system.

Massage therapy works via a combination of the following 11 mechanisms:

  1. Deactivating nociceptors.  Sometimes pain is a result of the nerves becoming irritated as they pass through layers of tissue and their local blood supply gets negatively impacted similar to a kink in a hose.  Though we can’t know for certain what’s happening beneath the client’s skin, it’s assumed that some techniques function by temporarily “unkinking” the blood supply and allowing the nerve to “fill up” in a way that allows the nerve to function better for a period of time.  It’s also possible that certain techniques might allow for ‘unkinking’ to happen for a longer period by creating some glide between tissues that were not gliding enough on their own.  This is likely what’s happening with “fascial” techniques that were originally thought to work via changing the shape of fascial tissue.  This is an example of an evolution in massage theory from thinking in terms of “balanced structure” to thinking in terms of the nervous system and its “ecosystem”.
  2. Ascending inhibition.  Ascending inhibition (AI) describes how “pain signals” from tissues get inhibited (at the spinal cord) by tactile inputs.  All of us utilize ascending inhibition when we instinctively hold a body part that hurts.  This is because the input from touch is inhibiting the “pain signal”.  AI contributes to a reduction of pain during the massage session, but it doesn’t explain why a client feels better after the session.  To understand post-session effects, we have to look at other mechanisms.
  3. Descending inhibition.  Descending inhibition (DI) refers to neural signals that start in the brain and inhibit “pain signals” in the spinal cord.  DI works similarly to AI except that instead of inhibiting “pain signals” through touch, the signals are inhibited from psychosocial factors such as feeling safe, trusting the therapist, believing the treatment will help, and past experiences in similar situations.  The benefit of being told “it’s going to be ok” is an example of descending inhibition.
  4. Distraction.  We’re all familiar with the practice of distracting ourselves to lessen our awareness of something unpleasant.  With massage, distraction can come from any sensation, whether it’s pleasure or “good pain”.  Distraction may not resolve the issue at its source, but having a reprieve from suffering can have positive impact on one’s resolve.  A reprieve will likely engage descending inhibition and can also impact one’s bio-immune responses to suffering, which in turn can impact the source of the issue.
  5. Pleasure.  Massage involves at least two types of pleasure.  The first arises from the application of strokes that move within a certain range of speed and pressure.  This is called affective touch or hedonic touch, and it’s what most people think of when they think of massage.  This particular form of touch activates specific pathways (c-tactile fibers) that engage pleasure and reward centers of the limbic system.  The second form of pleasure arises from the removal of unpleasant sensation—the pleasure of relief.  Both forms of pleasure will likely engage descending inhibition processes.
  6. Relaxation response.  If a person feels safe and cared for, this alone is enough to induce an autonomic relaxation response, and if they are being touched in a way that inhibits pain or induces pleasure in some way, that will add to that effect.  A relaxation response impacts the client’s physiology, which can have an indirect impact on pain states, which in turn impacts muscular responses at the spinal cord level, just as all of the previous items do.  
  7. Proprioception.  Proprioception refers to how the nervous system tracks the position of the body’s joints.  Through touch and movement, massage impacts proprioception and is likely partly responsible for why it may feel different to “inhabit” one’s body after massage (e.g. feeling taller, floaty, or more solid).  
  8. Body awareness.  As a client receives touch in areas that don’t normally receive touch, a client may start to become more aware of their body, similar to how one grows awareness of one’s body when learning how to swing a golf club or hold a yoga pose.  
  9. Presence and awareness of sensation.  The very act of focusing one’s attention on sensations in the moment is the basis for mindfulness meditation.  Being present in the moment can reduce anxiety and have many other benefits.
  10. Therapeutic relationship.  While it’s reasonable to think that massage works primarily through touch, the reality is that the therapeutic relationship that develops between the client and therapist is just as important as the touch component.  As highly social beings, simply being with someone that feels safe and is caring for you has enormous impact on the nervous and immune systems, and the meaning that is attributed to the touch component is different than what would be derived from a machine.  Clearly many of the items on this list are present if one uses a massaging device, but the addition of being cared for by another human is very significant.  Without a quality therapeutic relationship, the effects of the former mechanisms are limited and the effect of the next item is likely nonexistent.  
  11. Somatic awareness and embodiment.  Several psychological phenomena can emerge as the client’s nervous system lets go of defensive holding patterns that may normally be blocking awareness of internal psychological states, similar to how a quality vacation might remind a person of feelings that they haven’t felt while caught up with everyday responsibilities.  For example, sometimes a client comes to realize that they have been “holding it all together” and as their awareness moves into the sensations of the current moment and if they feel safe enough, a sort of “letting go” happens and one is given access to feelings that feel “deeper” or more authentic.  In this way, massage serves as a sort of concentrated vacation for both the body and mind.

These are the primary known or theorized mechanisms for how massage works.  Ultimately the end result of these processes is going to be related to pain, anxiety, pleasure, mobility, and embodiment.  Most of these will be related to activity in limbic regions such as the insula, anterior cingulate, nucleus accumbens, amygdala, and hypothalamus, while mobility will be related to pain processing and spinal reflexes.  

As one can see, understanding how massage works is much more involved than what is commonly thought, and hopefully over time society will slowly grow its awareness of the existence of these mechanisms so they can be more informed consumers and providers of massage therapy.  

Related topic: Posture and Interoception