The main component of ligaments, tendons, cartilages & spinal discs is collagen which is the most abundant protein found in mammals, with it's purpose being to actually connect cells together. The name collagen is derived from Greek & means 'produce glue'. The tissues mentioned above are also rich in proteoglycans which are 95% glycosaminoglycans (GAGs) & 5% protein. These GAGs act as a framework for collagen to model onto & consequently are responsible with collagen for continuously building & rebuilding ligaments, tendons, cartilages & spinal discs. The major precursor in GAG production is Glucosamine which is produced in the body from glucose & glutamine. Athletic endeavor, physical work or simply passing years means the body can no longer keep up with demand for Glucosamine & damage to the joints can occur.