Trigger Point: The Cause of Pain and Sensory Symptoms
Whether the injury is from muscle or nerve, the end result is perpetuating muscle spasms in the muscle. Muscle spasms are often palpable as tender muscle knots or tender regions in a taut muscle band that are painful when pressed. This muscle knot is called the trigger point. When the trigger point is examined microscopically, there are multiples of individual muscle fibers that have knots in them. When trigger points exist, muscles are shortened, tendons are pulled, blood vessels are squeezed and nerves passing through the zone are compressed. This causes pain locally and sometimes far from the site and sensory symptoms such as numbness and tingling. Sometimes, restricted range of motion occurs. The general consensus is that the formation and maintenance of trigger points in the muscles is the reason why patients experience pain and sensory symptoms. Trigger points can be formed quickly after a trauma or slowly over time when stress is applied to the muscle gradually; such is the case with habitual bad posture or repetitive motion injuries.