What are muscle “knots” & trigger points

The phenomenon of muscle knots is not uncommon. Essentially, muscle knots are sections within the various muscles of the body that have constricted and create consistent pain with each individual. They are commonly termed “Myofascial Trigger Points“. While there is not currently a definitive medical explanation as to why muscle knots form, several theories are undergoing testing.muscle-exploded-view

The generally accepted answer to why muscle knots form is that something triggers a reaction where the muscle never relaxes. In effect, the muscle is always in a state where it appears to be actively rather than passively in use. This is unusual, since even with such activities as weight lifting, running, or any type of heavy lifting the muscle goes through a series of off and on cycles. The constant active condition of the muscle leads to muscle spasm, which it turns acts as the root cause the muscle knot.

Surgically removing a portion of muscle know has led to the discovery of the presence of unusual deposit of protein within the tissue. There is also a theory that excessive amount of connective tissue surrounding the muscle may also contribute to the development of muscle knots. However, very little research has been done on the matter of connective tissue, so most doctors do not recognize that as a contributing factor in the development of a myofascial trigger point.

The physiology of a trigger point

The part of a muscle-knots1-733x1024muscle fibre that actually does the contracting is a microscopic unit called a sarcomere. Contractions occurs in a sarcomere when its two parts come together and interlock like fingers. Millions of sarcomeres have to contract in your muscles to make even the smallest movement. A trigger point exists when over stimulated sarcomeres are chemically prevented from their interlocked state.

NORMAL FIBRE: is a muscle fibre in a normal resting state, neither stretched nor contracted. The distance between the short crossways (Z bands) within the fibre defines the length of the individual sarcomeres. The sarcomeres run lengthwise in the fibre, perpendicular to the Z bands.
CONTRACTION KNOT: is a knot in a muscle fibre consisting of a mass of sarcomeres in the state of maximum continuous contraction that characterises a trigger point. The bulbous appearance of the contraction knot indicated how that segment of the muscle fibre has drown up and become shorter and wider

→ Note the greater distance between the Z bands of muscle fibres that extends from the contraction knot to the muscle’s attachment: the muscle fibre is being stretched by tension within the contraction knot. These overstretched segments of muscle fibre are what cause shortness and tightness in a muscle.

Normally, when a muscle is working, its sarcomeres act like tiny pumps, contracting and relaxing to circulate blood through the capillaries that supply their metabolic needs. When sarcomeres in a trigger point hold their contraction, blood flow essentially stops in the immediate area.
The resulting oxygen starvation and accumulation of the waste products of metabolism irritates the trigger point. The trigger point responds to this emergency by sending out pain signals.

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