Tuesday, May 22, 2012
Stretching and Cerebral Palsy: What you should know.
Stretching is most commonly performed to achieve a specific end result: elongation of a particular muscle or group of muscles. This seems relatively intuitive and would make sense to any lay person. The part that is not so intuitive is that the muscles themselves are embedded within a connective tissue matrix...which is in turn blended with other differentiated connective tissue (tendon) that is continuous with the outer layer (periosteum) of the bone. From there, the periosteum continues and eventually blends once again and the kinematic chain continues.
Muscle is defined as a tissue composed of bundles of elongated cells capable of contraction and relaxation to produce movement. Connective Tissue can be descried as a tissue developed from the embryonic mesoderm that consists of collagen or elastic fibres, fibroblasts, fatty cells, etc., within a jelly-like extracellular matrix. It supports organs, fills the spaces between them, and forms tendons and ligaments. Knowing these basic facts and definitions, their respective functional appearances within the normal muscle and the spastic muscle (CP) need to be defined. They should be the same, right? This couldnt be further from the truth. This is what the current (and most popular)approach assumes...that muscle is muscle and fascia is fascia. I have attached a very interesting and informative study that was performed to identify the similarities / differences between spastic and normal muscle tissue, spastic and normal extracellular matrix, as well as the differences between individual cells and collective bundles of cells for both. I recommend that you take the time to read it, but I will summarize its contents here in an effort to expediate my point (it´s effectively the abstract of the article): 1) The difference between bundles and single cells was much greater in normal muscle tissue (16 times stronger) than in spastic muscle (2 times stronger). 2) Actual muscle fiber strength is greater in spastic muscle than in normal muscle. However..... 3) Extracellular matrix strength / Connective Tissue strength is 43.5 times weaker!! Therefore, the ¨inconvenient truth¨ is exposed and a fundamental question is raised: if the spastic muscle itself is stronger than normal muscle, and the connective tissue attachments are 43 times WEAKER...what is really happening when you attempt to stretch that particular muscle(s)? In my professional opinion, it seems only logical that the likely result is further weakening and de-stabilization of an already weak connective tissue system...however, I am more than willing to set that staunch opinion aside if ever there was a way to guarantee this wouldn´t happen. The current reality is that, at best, there is no definite way to determine if the attempts to relax spastic muscles via stretching will not potentially be of some detriment. Indeed, there are some cases where some relief has been attributed to active stretching...however, these responses are transient and were most likely done in a very mild form.
The article goes into more important details (muscle fiber size and area is smaller in spastic muscle, for example), so I will leave those for the more curious to digest. In summary, I do not belong to the extreme end of the continuum in saying that ¨all stretching is bad¨ and that it absolutely shouldnt be done. My main message is that proper consideration be made to the actual mechanical and physiological benefits / consequences of ANY therapeutic intervention. If, through careful thought, consideration, and analysis, stretching is indicated...then it is obviously worthy of implementation. The harsh reality is that many forms of stretching are dispensed without any constructive analysis...which is fundamentally dangerous. To put a final point on this topic...forget about absolute ¨black and white¨solutions. There is a whole lot of grey to choose from! Cheers! Inferior Mechanical Properties of Spastic Muscles Due to Compromised Extra Cellular Matrix Material