Fascia is a dense connective tissue that is a crucial factor in posture and in the generation of muscular force. Due to its rigid structural nature and continuity throughout the body, it is often a “weak link” in soft tissue injuries and may be the first area of failure in traumatic or repetitive use injuries. Unfortunately, due to its poor vascular nature, it is also an area that often does not heal effectively on its own.

Effective Manual Therapy

Effective manual therapy approaches, such as the Airrosti treatment model, focus on detecting and correcting fascia issues as a critical component in rehabilitation. While clinical outcomes have continuously demonstrated the effectiveness of this approach, the question remains as to the exact physiological, histological, and functional mechanisms of action that are taking place in myofascial treatment.

One physiological mechanism that has been proposed by Rolf as early as 1977 is the colloidal nature of fascia in which the mechanical myofascial treatment could affect the viscoelastic nature of the ground substance through thixotropy. Thixotropic bonds may be seen in fascia and in the actin and myosin filaments of muscle as well. When performing manual therapy, the energy of the mechanical pressure will potentially decrease the binding affinity of the connective tissue and alter its viscoelastic properties. These thixotropic changes to viscoelasticity have been documented by multiple researchers including Twomey & Taylor (1982), Juhan (1987), and Threlkeld (1992). The issue with this mechanism acting alone is that the documented stressors necessary for this thixotropic based plastic deformation to occur would likely be outside the therapeutic levels of manual treatment. (Currier & Nelson 1992 and Chaudhry et al 2008)

Another mechanism that has been postulated (Oshman 2000) is that manual therapy pressure may create a charge differential through a piezoelectric effect on fibroblast activity. The external pressure could cause an upregulation in fibroblast activity leading to increased collagen production locally. This is an interesting application of Davis’ Law and may be applicable to the increased healing rate with myofascial therapy, but it does not explain the immediate “release” that often occurs in the clinical setting.

Most recently, a neurophysiological rationale has been suggested for the immediate and sustained improvement in kinetic chain function that is noted with manual fascial therapy. This centers around mechanoreceptor stimulation of Golgi receptors (GTOs and others located directly in the fascia), interstitial receptors (Type III and Type IV), and Ruffini ending receptors (Type II) according to Bandy (2001), Schleip (2003), and Alter (2004) and the resultant effects on the central and autonomic nervous systems.

The mechanical pressure on Golgi receptors triggers proprioceptive input into the central nervous system that, through the process of autogenic inhibition, overrides the dysfunctional overactivity of muscle, fascia, and connective tissue. This creates an inhibitory response in the muscle spindle itself and has been shown to decrease gamma motor unit activity. When combined with tissue stretching, this results in improved range of motion and increases in neuromuscular efficiency.

Mechanoreceptor stimulation of interstitial and Ruffini ending receptors can have a direct impact on the autonomic nervous system. These effects can manifest as decreased muscle tonus through a lowering of the sympathetic state via activation of the anterior lobe of the hypothalamus. They may also include changes to local fluid dynamics that may alter the viscoelastic properties of connective tissues. Finally, autonomic input can trigger vasodilation that may facilitate healing through increased delivery of necessary nutrients as well as through waste product removal.

Is Manuel Myofascial Therapy Effective?

In conclusion, manual myofascial therapy can affect tissue dynamics through a variety of mechanisms that can include thixotropy, piezoelectric changes, and neurophysiological responses to improve structural function and neuromuscular efficiency. The changes can account for the immediate alterations that can be detected in fascial restrictions and in muscular synergist hypertonicity plus the increased rate of healing that is well documented clinically.