What is pain? How much of pain is physical and how much is mental? We all deal with pain differently. Some people turn to prescription pain killers, while others will do anything and everything to not have to take them. After years of medications that didn’t truly work, I’m the latter. One of the hardest things I have ever had to learn in life is pain management. Acute pain can be disruptive, limiting our training and ability to partake in the physical activities we love. Chronic pain can be debilitating. So, how do we deal? Have you ever wondered why you immediately rub your leg after running into the coffee table?
The science of gate control
Pain is such a subjective term and an experience that varies person to person. Why does one person experience pain and another not when presented with the same pain-inducing stimulus. The Gate Control Pain Theory states that pain is a function of the balance between the information traveling into the spinal cord through large and small nerve fibers (Melzack & Wall, 1965). Large diameter fibers (associated with touch, pressure, and vibration) and small diameter fibers (such as pain) meet at two places in the spinal cord: T cells and inhibitory cells (Melzack & Wall, 1965). Melzack and Wall (1965) explained that both large and small fiber signals excite T cells, and when the output of the T cells exceeds a threshold, pain exists. These T cells are said to be the gate to pain (Aronson, 2002; Melzack & Wall, 1965; Taylor & Taylor, 1998). Inhibitory cells act to inhibit activation of the T cells and have the ability to shut that gate (Melzack & Wall, 1965).
When large and small fibers have been stimulated, they will activate T cells: opening the pain gate. The large fibers will also activate the inhibitory cells: closing the gate. The small fibers will block the inhibitory cells: leaving the gate open (Aronson, 2002; Melzack & Wall, 1965). Meaning, the more large fiber activity relative to thin fiber activity, the less pain you will feel.
This explains why we tend to rub our skin when we run into something. We rub the point of impact. And for as long as one rubs that point of impact, pressure will be perceived, rather than pain, because the message of pressure (large fibers) is ‘closing’ the gate and preventing the message of pain (small fibers) from passing through (Aronson, 2002). If the amount of activity is greater in these large fibers, there should be little or no pain. However, if there is more activity in small fibers, then there will be pain (Aronson, 2002; Melzack & Wall, 1965).
The science in practice
The Gate Control Pain Theory can explain all types of pain, although it is quite often used to explain chronic and phantom limb pains (Aronson, 2002). The ‘gate’ plays a very important role in pain management. As mentioned, we inherently respond to certain pain situations by rubbing or applying pressure to the point of impact, closing the gate. This theory also can explain the effectiveness of other pain management techniques, such as applying ice or analgesic balms. These treatments change the perception of pain by activating more large fibers, sending the message of pressure instead of the message of pain (Aronson, 2002).
As I have struggled, and continue to struggle, with chronic pain, I love learning about the science and the reality of pain. Physiological pain can quickly and easily manifest into psychosomatic pains. How can I best manage my pain – acute and chronic – in a way that prevents me from losing control my gate? For the person who suffers chronic pain, stubbing a toe can quickly elicit negative thoughts, feelings, and sensations. I know I want to limit and control the negative! If I know rubbing and kissing a ‘boo-boo’ will make it feel better, I’m sure going to use it!
Aronson, P. A. (2002). Pain theories: A review for application in athletic training and therapy. Athletic Therapy Today, 7(4), 8-13.
Melzack, R., & Wall, P.D. (1965). Pain mechanisms: A new theory. Science, 150, 971-979.
Taylor, J., & Taylor, S. (1998). Pain education and management in the rehabilitation from sports injury. The Sport Psychologist, 12, 68-85.