of the movement of cytoplasm within a cell - and even the nucleoplasm inside its nucleus - we should consider the potential directions of force generated within the nucleus , cell or organism as well as those being imposed from outside . Taking this analogy one step further we could seriously deform the balloon by putting a hole in it to release some of or all the water within . If that hole was fitted with a sort of two-way valve , the fluid level could be subject to controlled release and replenishment . Does this start to remind you of our lymphatic system ?
The recently discovered human body of water , or interstitium , is described by Benias et al .( 7 ) as a body-wide fluid-filled compartment in the sub-mucosa , dermis , fascia and vascular adventitia with a supporting reticular network of collagen that responds to rhythmic compression , feeding into the lymph system as well as absorbing shock to the tissues . They conclude that “ The presence of fluid has important implications for tissue function and pathology ”.
Through her study of hyper- and hypomobility joint disorders , Langevin investigates how the sliding capacity at the interface between fascial layers influences proprioceptive signalling , and nociception in particular . Proprioception is defined here as awareness of direction of joint movement and comes under the umbrella term of interoception , which broadly equates to all processes of internal awareness and includes the deep pressure sensation experienced in sustained , non-painful stretching of the type felt in yoga practice .( 8 ) She likens this to the deep stretch sensation experienced in the connective tissue during acupuncture , and differentiates between normal and sheer strain , describing them as aligned and unaligned forces that deform tissues . In standard massage treatment the direct ischemic pressure ( DIP ) would be a normal strain , whereas a sheer strain uses opposing forces to shift parts of the body in opposite directions . The effect of either of these types of strain in the tissues will depend on the viscoelasticity , or stiffness , of the tissues themselves . Viscoelasticity is a term combining the properties of elasticity and viscosity - a sliding scale between solid and liquid involving hyaluronic acid concentration , collagen density and cross-linking , glycosaminoglycan composition and water content . So it seems that the adhesions between layers of fascia will inhibit their ability to slide in response to movement intention . Langevin goes on to suggest that ion channels ( openings in the cell membrane through which inorganic charged atoms or molecules can travel ) may be responding to the type of internally generated deformation in the membrane rather than externally applied force .
In their 2017 investigations into synthetic tissue engineering , Yinji-ma et al .( 9 ) aimed “ to reproduce the non-linear mechanical properties of real biological tissues ”. The J-shaped behaviour they describe involves a mechanism to regulate stress-strain relationships , preventing damage from excessive stress levels by limiting strain . This mechanism is engaged when the limit of initial stretchability of the soft tissue has been reached . It involves the progressive orientation of random collagen fibres in the tissue to line up parallel to the vector of force , thereby resisting the strain - like pulling on the reins of a horse . The ability of collagen to achieve this purpose depends on the curve and chain microstructure within it . The basic form of collagen is a triple helix . These coiled fibres are wound between and around each other in a wavy pattern that can bend and twist under strain to uncoil until the fibres themselves begin to straighten out in the direction of the stress . Like a spring , the collagen has a limit to the amount and duration of stress beyond which it is incapable of resuming its original form . Where too much strain is identified in an area of tissue , the natural biological response , after initial pain and inflammation , is to lay down more collagen , thereby reinforcing that area against future or further strain ( i . e ., fibrosis ). This fibrosis may have the unfortunate effect of hampering the proprioceptive signalling in that area , creating a veritable ‘ blindspot ’ where the brain is unable to respond by any means to dysfunction to reinstate systemic integrity . Going back to the classification of fascial types put forward by Kumka and Bonar mentioned above , three of the four categories include proprioception in the list of functional properties .
Chen and Langevin et al .( 10 ) explain a duality fundamental to the function of fascia with the terms exteroception , whereby we interact with the outside world by means of our five primary senses , and interoception , involving a combination of neurological processes that govern our awareness of our own internal landscape . They point out that interoceptive networks involve a twoway interplay between the brain and other body organs through ascending and descending pathways . Biochemical , mechanical and electromagnetic signals delivered to neural receptors via neural and non-neural pathways are interpreted by the brain . All this happens naturally at lightning speed when the body is in good working order , but sometimes an unrecognised pathology will disrupt this process . Simply put , we assess and respond to our universe through signals travelling inward from the outside as well as those travelling outward from the inside . Basically , if we can ’ t feel it , we can ’ t fix it .
Implications for practice
So where does this leave the therapist ? How can we be sure the theory translates correctly into our practice ? New knowledge sometimes challenges the practices we have come to rely on . We must be prepared for continual assessment of our methods , keeping the best elements of old technique and reforming them in a methodical process that will no doubt include some degree of trial and error . The key to success is communication with our patients , as they need to understand what we are doing and why . The processes driven by new knowledge may indeed be
70 | vol28 | no2 | JATMS