In vitro modeling of repetitive motion strain and manual medicine treatments: Potential roles for pro- and anti-inflammatory cytokines

Despite positive clinical outcomes documented post-treatment with a variety of manual medicine treatments (MMT), the underlying cellular mechanisms responsible remain elusive. We have developed an in vitro human fibroblast cell system used to model various biomechanical strains that human fibroblasts might undergo in response to repetitive motion strain (RMS) and MMT. Our data utilizing this system suggest that RMS induces disruption of cell-cell and cell-matrix contacts, which appear are reversed when a modeled MMT is also added to the treatment protocol. Similarly, while RMS induces secretion of several inflammatory cytokines, modeled MMT attenuates this secretory response. In terms of strain direction, fibroblasts strained equiradially exhibit unique cytokine secretory profiles vs. those strained heterobiaxially. Taken together, these data suggest that this cell model may prove useful in identifying the cellular mechanisms by which various fascial strains used clinically to treat somatic dysfunctions yield positive clinical outcomes such as reduced pain, reduced analgesic use and improved range of motion.