Joints have cartilage in between them, which help to make the movement flexible. Joints are described structurally and functionally. Structural classification is how the bones connect to each other; function is the degree of movement between the articulating bones.
- "Joint definition". eMedicine Dictionary. 27 April 2011. http://www.emedicinehealth.com/script/main/art.asp?articlekey=4074. Retrieved 27 January 2012.
- Ellis, Harold; Susan Standring; Gray, Henry David (2005). Gray's anatomy: the anatomical basis of clinical practice. St. Louis, Mo: Elsevier Churchill Livingstone. pp. 38. ISBN 0-443-07168-3.