High Quality Content by WIKIPEDIA articles! A tendon (or sinew) is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments and fascia as they are all made of collagen except that ligaments join one bone to another bone, and fascia connect muscles to other muscles. Tendons and muscles work together and can only exert a pulling force. Normal healthy tendons are mostly composed of parallel arrays of collagen fibers closely packed together. The dry mass of normal tendons, which makes up about 30% of the total mass in water, is composed of about 86% collagen, 2% elastin, 1?5% proteoglycans, and 0.2% inorganic components such as copper, manganese, and calcium.