疤痕和疤痕组织

jacky

Scars and Scar Tissue

by Patrick   on October 3, 2011

The topic of scars and scar tissue is one that comes up frequently when talking about athletes, tissue quality, and massage therapy.  A recent question about scar tissues and adhesions on strengthcoach.com got me thinking more about the topic and since I have been asked about this in the past I figured I would cover some of my ideas.  While the original question was not about scars in particular, I felt that it would be good to include them in this piece as well.
Scars
When you hear the word “scar” you probably think of a gnarly piece of skin on someone’s knee, shoulder, or back where the skin color and texture is a bit different and the tissue appears to be popping off the body.  These types of scars are commonly seen following some sort of surgery or injury.
Karel Lewit has discussed at length in his textbook, Manipulative Therapy: Musculoskeletal Medicine, about the problems that, what he calls, active scars present to the movement system if they have not been treated properly.   Skin plays an important role in our proprioceptive and tactile senses, giving us information about where our body is in space.  Active scars, on the outside of the body, can distort our proprioception and potentially create dysfunctions of both muscles and joints as they typically pass through several layers of soft tissue.  This interruption of tactile perception may occur following a surgery and Lewit states:

“It is not sufficient to assess the sensitivity of the scar alone.  Surgery may also damage cutaneous nerves, in which case hypesthesia will be present, but sometimes also paradoxical hypersensitivity.  In both cases we should attempt to improve sensibility.  As long as this is abnormal, then the tone of connective tissues and muscles will remain abnormal, as will their reactions.  This tactile perception deficit may be indicative of muscle spasm, which means that the patient has insufficient muscle control.  Hypersensitive skin may also be associated with paresthesia and even pain (sometimes referred pain).” (pgs. 227-228)

Scar Tissue
Scar tissue is a bit different than an active scar.  When people refer to scar tissue they often are talking about the scarring or densification of the fascial/connective structures underneath the skin not visible to the eye like a scar is.
Scar tissue tends to form following some sort of injury or damage where the body deposits collagenous tissue which helps to aid in the repair of injury and improve the structural integrity of the connective to allow for proper support so that damage does not occur again.
You will often hear various rehabilitation professionals (Physical Therapists, Chiropractors, Orthopedic Surgeons, etc) or massage therapists talk about how there is “scar tissue” that needs to be broken up (or broken down depending on how you look at it) so that the athlete can get back to full function.  Interestingly, a recent paper by Langevin et al. (2011) found that there was reduced fascial shear strain in the thoracolumbar fascia of those with chronic low-back pain.
The thoracolumbar fascia has a number of dense layers separated by superficial layers.  These layers require a healthy slide over one another so that fluid movement can take place.  When these layers become glued together movement may be inhibited.  Langevin and colleagues found that shear strain was approximately 20% lower in those with low back pain compared to pain free subjects.  The authors concluded that this loss of shear between fascial layers may be due to abnormal movement patterns or other connective tissue pathology.
One of the cells of the fascial system, myofibroblasts, actually contain some smooth muscle properties and can contract in a smooth muscle like (IE, involuntary) manner.  This active contraction of the myofibroblast cells has been known to take place in times of healing and injury repair in response to excessive loading, which Schliep and colleagues have detailed in the thoracolumbar fascia.
Because fascial layers tend to lose their shear ability in movement dysfunction situations, potentially due to an increase in myofibroblast activity and involuntary fascial contraction, and because fascia has a very strong sensory role and is rich with nerve endings perhaps this increase in scar tissue/fascial densification creates a scenario where proprioception becomes diminished thus negatively impacting movement?
Interestingly, Travell and Simons noted that trigger points can often develop within scar tissue.  Trigger points are hotly debated as to what they exactly are but it appears that there is some sort of abnormal nerve activity taking place (whether you call it a trigger point or not) which would fit in line with the potential theory that the dense, thick fascia/scar tissue is interrupting nerve activity.  Additionally, because trigger points are known to have referral patterns/symptoms, perhaps this is the referred pain from scars that Lewit was referring to above?
What Can We Do About It?
This is always the interesting question.  If you asked me two years ago I may have said that we are trying to break up that scar tissue. These days I can’t say 100% that this is incorrect, but I can’t say it is 100% correct either.  The body isn’t a piece of wood or clay that we can simply mold.  Rather, the body is a living organ that interacts with what we do to it in hands on (or hands off) treatment.  Most have seen the impressive Rolfing pictures of an individual going through the treatment process and the amazing postural changes the individual is able to make.  I think that some of these changes are actually probably more a function of improvements in wellbeing and confidence that may have been brought on by the interpersonal relationship formed between the client and therapist as they go through the intimate 10-treatment process.
So, if the body is not something that we can mold and shape with our hands from the outside what might really be going on when we are attempting to treat scar tissue?
I think in certain instances we are attempting to create a low-grade inflammatory response to help re-start the healing process.  It is these situations where I believe you see benefit in things like graston/astym, fascial manipulation in the Stecco method, Cyriax friction or periosteal friction, etc.  You are essentially creating an inflammatory response which then “rallies the troops” and increases fibroblast activity and starts the healing process over again allowing you to attempt to correct what maybe didn’t go right the first time (IE, the body did not heal properly).
In other instances you are not really attempting to create inflammation but you are attempting to deal with huge amounts of dense tissue/scarring by using your therapy to interact with the nervous system of your client to help improve proprioception in areas where it has been lost or diminished because of the increased extracellular matrix and decrease shear force of fascial layers. This may be were techniques like ischemic compression, skin stretching, dry needling, slower fascial techniques (like Myers work or Rolfing), or general massage techniques for relaxation would fall into place (I would put foam rolling here as well).
Conclusion
With so much of the research on the fascial system in its infancy it is difficult to say exactly what is taking place and how we are impacting the body with our therapies.  These are just some of my ideas and as I learn more and as more of the science becomes available these ideas may change.  What is fascinating about all of this is the interplay between all of the bodies systems and I think this is sometimes overlooked.  Therapists who are often excited about myofascial therapy will commonly exclaim, “It’s all connected”, when referring to the fascial system.  However, it is important to remember that it really all is connected….not just the fascial system, but everything – nervous system, circulatory system, etc (which massage therapists tend to overlook).  The systems all work together and attempting to figure out how we can influence these systems is perhaps the most interesting journey to embark on.
Patrick
patrick@optimumsportsperformance.com
References
Lewit K. Manipulative Therapy: Musculoskeletal Medicine. Churchill Livingstone. 2010.
Chaitow L, DeLany J. Clinical Application of Neuromuscular Techniques Vol. 1: The Upper Body. Churchill Livingstone. 2000.
Langevin HM, et al. Reduced thoracolumbar fascia shear strain in human chronic low back pain. BMC Musculoskeletal Disorders 2011; 12: 1-36.
Langevin HM, et al. Ultrasound evidence of altered lumbar connective tissue structure in human subjects with chronic low-back pain. BMC Musculoskeletal Disorders 2009; 10: 151.
Schleip R, et al. The fascial network: an exploration of its load bearing capacity and its potential role as a pain generator. Published in: Vleeming A et al.: Proceedings of the 7th Interdisciplinary World Congress on Low Back & Pelvic Pain, Los Angeles, November 9-12, 2010, ISBN 978-90-816016-1-0, page 215-218.
Schleip R, Klinger W, Lehmann-Horn F. Fascia is able to contract in a smooth muscle-like manner and therby influence musculoskeletal mechanics. Proceedings of the 5th World Congress of Biomechanics, Munich, Germany. 2006. 51-54.
Schleip R. Fascial Plasticity: A new neurobiological explanation part 1. Journal of Bodywork and Movement Therapies 2003; 7(1): 11-19.
Schleip R. Fascial Plasticity: A new neurobiological explanation part 2. Journal of Bodywork and Movement Therapies 2003; 7(2): 104-116.
Yahia L, et al. Sensory  innervation of human thoracolumbar fascia: An immunohistochemical study. Acta Orthop Scand 1992; 63(2): 195-197.
Simons D, Travell J, Simons L. Myofascial Pain and Dysfunction: The Trigger Point Manual, Vol 1: The Upper Half of the Body, 2nd ed. 1998. Williams and Wilkins. Baltimore, MD.



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