The beginning of a tendon is where it connects to a muscle. Collagen fibers from the inside of the muscle are the same as those of the tendon. A tendon inserts into bone at an enthesis. At this point, the collagen fibers are changed into bone tissue. Tendons can not create any pulling force of their own. The tendons transfer the movement of muscles. They can create an elastic force if stretched. Tendons are part of the human body often connected to joints.