Fibroblasts within tissues are exposed to a dynamic mechnical environment, which influences the structure integrity of both healthy and healing soft tissue. Fibroblasts secrete a nonrigid extracellular matrix that is rich in type I and/or type III collagen. In addition, dermal fibroblasts also secrete large quantities of hyaluronan in response to inflammatory stimuli. During wound healing, dermal fibroblasts switch from a migratory, repopulating phenotype to a contractile, matrix-reassembling phenotype.