Our muscles consist of a series of fibres that contract and relax together. Sometimes this doesn't happen properly and some of the fibres are relaxed whilst other are contracted and this this is known as a trigger point. Muscles get in this state for a number of reasons, like over stressing when lifting, sneezing, poor posture, repetitions, etc.

The brain has great difficulty in pinpointing internal pain in the same way that it can external pain. In general it can only pinpoint pain in areas that we can touch. The brain identifies the location of internal pain in the best way it can. That is why the left arm aches when we have a heart attack. This is referred pain. Similarly, a problem with the shoulder muscles can make the wrist hurt.

The effect of a trigger point in a muscle is nearly always referred pain. Abdominal trigger point whether within the abdominal wall or internally within the muscles of the internal organs refer pain to other parts of the body. Abdominal wall trigger points can mimic gallbladder pain for example. Gallbladder pain which is the result of the cystic duct muscle contracting violently causes pain to the right shoulder. Spasm in the gallbladder can cause a slightly different pain profile and there is even pain related o a spasm in the sphincter of oddi which regulates the flow of bile into the duodenum.

It is important to keep all these muscles in good condition which is usually done by rhythmic activity such as walking. This moves the internal organs in a massaging movement. Alternatively therapy can be applied to the muscles by stretching and massaging them.

Sometimes the muscle trigger point is close to where a nerve routes through it and this can affect the performance of he nerve. The vagus nerve regulates our digestion. It has such a complex route through the body and it can be affect by a trigger point anywhere along its course. This is why it is important to keep the nerve in good condition by normal activity or stretch and massage.