Gate Control Theory that explained the pain mechanism was published by researchers Ronald Melzck and Patrick Wall in the year 1965. Afferent (sensory) nerve fivers transmit sensory nerve impulses from all over the body, though the spinal cord, and up to the brain. According to the theory, when the nerve impulses arrive at the spinal cord, they must pass through a “gate” in order to reach the brain and be recognized.
Essentially, impulses will travel to the brain if the gate is open. But if the gate is closed, no sensory input is transmitted to the brain and no sensation is perceived. The gate opens in response to impulses along the larger fibers that detect light touch, temperature, and pressure. Theoretically, light touch or pressure interferes with pain by closing the gate so the pain impulses cannot pass through to the brain, thus reducing the pain and the perception of it.
In other words, massage can reduce the sensation of pain. This theory is supported by the natural tendency for people to rub a bumped shin or hold their hand over a sore area. According to Weber’s law, “The increase in stimulus necessary to produce the smallest perceptible increase in sensation bears a constant ratio to the strength of the stimulus already acting”. It means that just a little bit more will change the perception.
For an application of massage to alter or change a sensory perception, the intensity of the application must match and barely exceed the existing sensation. To overcome a perception of cold you would need to apply a compress which is at minimum one degree warmer than the areas temperature to create a sensation of warmth. For example, focusing on pain tends to increase it, whereas ignoring the pain tends to decrease it. Other signals from the skin senses can also close the gate. This process explains why massage, ice, and heat relieve pain.