Scar Tissue and Pain: Part 2

Scar Tissue Formation Between Muscle Layers

This is the second article in 3 part series discussing the effects of scar tissue on pain and common musculoskeletal conditions.  The first article provided background information on what scar tissue is and how it develops, and discussed how scar tissue can cause muscles to become tight, weak, and painful. (click here to review the first article).

 

When we think of muscles we often think of them in isolation. For example, where is the biceps muscle? or what does the quadriceps muscle do?  But in the real word this is too simplistic.  We also need to be aware of how muscles move and interact with each other.  For example, one of the key things muscle need to be able to do is to slide and stretch against each other.

You see within the body muscles are arranged in layers which overlap each other. As different muscles begin and end at different locations, and because these various muscles stretch and contract at different times and at different rates, each muscle and muscle layer needs to be able to move and slide against the other structures they come in contact with.

When scar tissue is formed along damaged muscles, in many cases it can cause a muscle to become stuck or adhered to an adjacent muscle. This will have 2 major effects: first, it will greatly limit limit flexibility and mobility; and second, will compromise strength.

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1. Mobility Restriction

As a joint moves all of the muscles on one side of the joint will stretch, and the muscles on the other side of the joint will contract (i.e., shorten).  But the the magnitude of the change in length (i.e., how much each muscle stretches or shortens) will vary between different muscles.  This means that with any movement, muscles need to move and slide against one another.  If the muscles are stuck together and are unable to freely slide against each other the flexibility of the entire joint will be compromised

2. Strength Restriction

Joints move through muscle contraction. This process is like a pulley system which pulls one end of the muscle towards the other to create joint movement. This works well as long as the force generated at one end of the muscle can reach the other end (i.e., the force can be transferred from the origin of the muscle to its insertion). However, if scar tissue forms between two adjacent muscles it will prevent the force generated within the muscle from reaching the other other end of the muscle.

Here is a simple analogy…….. imagine a rope tied to a stone.  To pull the stone towards you you pull on the rope.  The pulling force you generate is transferred through the rope to the rock.  Now imaging the rope being surrounded by several other ropes, and the rope you are pulling on is tangled and stuck with another rope.  In this scenario, as you pull on the rope some of the force is caught and dissipated at the tangle, and less force reaches the rock.  You now have to pull much harder for the same effect.  This same thing happens within the body, making muscles work much harder than normal.

This not only wastes energy and makes movement and muscle contraction  much less efficient (this is a bid deal for athletes and people with physically demanding occupations), but this creates abnormal and excessive stress on the body which over time can lead to larger scale tissue damage and pain.