In response to a bone or ligament stress or injury, surrounding muscles may tighten as a protective measure. A muscle that tightens for a prolonged period can eventually go into a chronic spasm.
As a muscle goes into spasm, blood flow is restricted due to increased pressure. Certain chemicals, such as carbon dioxide and lactic acid, build up and cause further pain. The restriction is called vaso-constriction, meaning a tightening of blood vessels. Vaso-constriction then often worsens existing pain and swelling, creating a downward spiral.
Massage helps to break spasms and to release accumulated carbon dioxide through the lungs and lactic acid through the kidneys. This release allows normal circulation and function to return. For this reason, drinking lots of water after a massage facilitates the release and excretion.
Variations of massage therapy include reflexology, acupressure, therapeutic touch, deep tissue, and hot stone massage to name a few.