Myofascial pain syndrome (MPS) is clinically defined as a regional pain syndrome characterised by muscle pain caused by myofascial trigger points (MTrPs). Often overlooked or misdiagnosed, pain due to MPS is common and may range from an annoying dull ache to debilitating pain capable of mimicking nerve root irritation, osteoarthritic type pain and even visceral pain.
Peripheral intramuscular nociceptors can become sensitised by mechanical ischaemic and/or peripheral inflammatory factors resulting in a physiological cascade involving the the release of excess acetylcholine by the motor end plate. This in turn leads to the development of a contraction ‘knot’ within the muscle, commonly referred to as a MTrP. This localised contracture has been proposed to further impair local circulation resulting in an energy crisis which in turn results in further nociceptive sensitisation and so the cycle continues.