Pain is an alarm initiated upon tissue injury, carried along fairly specific nerves, and ultimately experienced according to the past experience of the sufferer. Our body has its own analgesics to relieve pain. They are a group of opiate proteins called endorphins with special pain-relieving properties. They are naturally found in the brain and are distributed throughout the nervous system. They bind to specific brain tissues involved in the perception of pain.
All sensation from the body is carried through the spinal cord along the posterior route, says Dr. A.V. Srinivasan, an eminent neuro-physician. It consists of two divisions – medical and lateral. The medical division carries sensation such as pressure, vibration, movement, position and fine touch. The lateral division carries pain and temperature.
When pain balms are rubbed, the pressure and movement sensations are produced in excess. This is turn sends more sensory input via the larger division of the posterior route which blocks the pain sensation through the lateral division of the posterior route to the spinal cord. The medial division blocks the pain sensation at the gate entry zone of the spinal cord. This mechanism of pain relief can be extended to acupuncture and never stimulations also, he says.
Therapeutic measures relieve pain by increasing the level of endorphins. Pain balms generally contain 3 components – methyl salicylate, menthol and camphor. These are easily absorbed through the skin. Menthol is a white crystalline substance and a principal constituent of oil of peppermint.
Role of the balm includes a local anesthetic effect which acts along peripheral nerve endings. These analgesics are chemically similar to endorphins and they relieve pain by binding to the same sites as endorphins. Experience of pain is psychological and subjective.
Although these analgesics have a special pharmacological effect in relieving pain, it is actually the amount of pressure applied and the movement that plays a significant role. Also other measures that increase confidence also will ease pain.
While methyl salicylate absorbed through the skin acts as an analgesic, menthol dilates the blood vessels. Because of the increased blood flow one gets a cool sensation in the balm- applied area. This is useful in case of headache and rheumatic pains. Camphor also acts as a rubefacient and mild analgesic.