"Deep Tissue" Massage: How much pressure is too much?

A 38 year old woman suffers permanent shoulder drop after a "deep tissue" massage caused damage to a spinal accessory nerve.

A 59 year old man suffers a deep hematoma, numbness, and swelling after being injured by a deep tissue massage to his hip.

A client tells a massage therapist that he wants more pressure. She complies. He again asks for more pressure. She complies. He again asks for more pressure. Unable to exert any more pressure with her hands, she resorts to using a hand-held tool to apply more pressure without hurting her joints. Shortly after, she receives an email from her employer that the client is suing their business, claiming that he was injured by the massage.

How much pressure is too much?

What exactly is "deep tissue" massage? If you ask a dozen massage therapists, you'll get a dozen different answers. Often they will say it's massage that is meant to target "deeper" tissues. They will also often say that targeting these deeper tissues doesn't need to require a lot of pressure. However, in practice, when people use the term "deep tissue" massage, they usually mean massage with a fair amount of pressure.

The term "deep tissue" massage is really, I believe, a misnomer. It's based on a misunderstanding of how massage works. We have a brain, a spinal cord, and nerves that go from the spinal cord to the periphery. When we apply our hands to the client's skin and glide, rub, or knead, we stimulate mechanoreceptors at nerve endings in the skin. Impulses are generated, travel up the nerves to the brain. The brain processes this information and, in turn, sends out impulses that create the changes we observe. It may slow the breathing, lower the blood pressure, and turn down the volume on the sensations of pain and tension.

As far as we know, most of the sensory nerves that respond to massage are located in or just below the skin. There are deeper sensory nerves but most of them seem to be nociceptive in nature - that is, they respond to potentially threatening stimulus like excessive pressure. They generate "danger signals." Generally, we want to avoid creating nociception. There is very little known about what happens with these deep nociceptors when we use a lot of pressure during massage. We do know that no matter what, the vast majority of the input to the nervous system is coming from the sensory nerves in the skin.

There is a popular but mistaken belief that it is our pressure on the tissues that creates the change. An entire industry has been built on teaching massage therapists that many pain problems are somehow caused by tight or restricted fascia and that therapists can loosen or stretch fascia by exerting a lot of pressure on the skin, pushing hard into the body. Even though we know this is false and that fascia is too tough to be stretched by pressure from our hands, this idea remains common among massage therapists, personal trainers, and some clients. Indeed, it may feel as if we're stretching something but it is, in fact, the nervous system which is creating any change.

As for changing muscles, they are controlled by impulses from the nervous system. There is nothing we know about them physiologically to lead us to believe that pushing hard on them is what creates the change in sensation we feel. Indeed, once I started learning more about the role of the nervous system in manual therapy, I started changing my approach. Instead of pushing hard, trying to have an effect on deep muscles, I tried putting my hand on the skin and exerting a sustained stretch on it. I was amazed to find that clients often experienced relief from the sensation of "tightness" that they had felt. Obviously, I didn't need to push hard to "reach" those deeper muscles. Somehow, the nervous system was doing the work for me. This was good news for both me and my clients. It meant that I didn't have to hurt myself in order to help others feel better. It meant that clients did not have to tolerate having me jam my fingers or elbows into their abdomen, hips, or back. It meant that I could treat clients who could not tolerate a lot of pressure. It meant that it was possible to treat areas that were covered with a layer of adipose tissue. It meant I didn't have to create pain in order to try to get rid of pain.

Why is it that clients often crave a lot of pressure? I think there may be a number of reasons. If a client has been led to believe that it is necessary to use a lot of pressure to achieve results, they will associate a lot of pressure with relief. If they are led to believe that massage must be painful in order to be therapeutic, they will not feel satisfied if they do not feel pain.

Even if we haven't been misled into thinking those things, there is the strange phenomenon of "it hurts so good." We can have an annoying ache by our shoulder blade and we want more than anything for someone or something to push on it. It intensifies the sensation but yet it feels good. What is that all about? I wondered about this and had an opportunity to ask the noted pain researcher Lorimer Moseley about this when he was keynote speaker at the first San Diego Pain Summit. Moseley said that since pain is, by definition, an unpleasant sensation, he would argue that the feeling of "it hurts so good" is not really pain. He did say he would agree that it is nociception and that this can initiate a cascade of physiological events, such as releasing endorphins, that can temporarily relieve the sensation of pain. This is probably why some painful therapies can appear to work. However, we know that repeated nociception can end up sensitizing the nervous system and so he cautioned against relying on this too much.

Massage therapists who come to realize this often face a dilemma: what does a conscientious massage therapist do when a client wants what we believe to be excessive pressure? I'll leave that for another blog entry because that is a whole subject in and of itself. For now, I will just leave readers with the reminder that, while generally safe, massage is not entirely without its risks. Most massage therapists will, at worst, leave a client sore for a couple of days. While this should always be avoided, it can happen and at least it is temporary. However, as noted at the beginning of this article, there have been cases where individuals have suffered more serious harm from excessive pressure or have been faced with the possibility of a law suit from a client who believes they have been injured.

 If both massage therapists and their clients are educated about how massage works, injuries to the client should be able to be avoided. None of us wants to end up being the next case report on PubMed. A systematic review on the safety of massage therapy has shown that serious adverse effects are rare. If we let the principle of Do No Harm be our guide, we should be able to keep massage therapy a very safe modality.