Like ligaments, aponeuroses, and tendons, fasciae are dense regular connective tissues, containing closely packed bundles of collagen fibers oriented in a wavy pattern parallel to the direction of pull. Fasciae are consequently flexible structures able to resist great unidirectional tension forces until the wavy pattern of fibers has been straightened out by the pulling force. These collagen fibers are produced by the fibroblasts located within the fascia.
Fasciae are similar to ligaments and tendons as they are all made of collagen except that ligaments join one bone to another bone, tendons join muscle to bone and fasciae surround muscles or other structures.
Fasciae are normally thought of as passive structures that transmit mechanical tension generated by muscular activities or external forces throughout the body.
The function of muscle fasciae is to reduce friction to minimize the reduction of muscular force. In doing so, fasciae provide a supportive and movable wrapping for nerves and blood vessels as they pass through and between muscles.