After completing this chapter, you will be able to:
Categorize joints based on structure and movement capabilities.
Explain the functions of articular cartilage and fibrocartilage.
Describe the material properties of articular connective tissues.
Explain advantages and disadvantages of different approaches to increasing or maintaining joint flexibility.
Describe the biomechanical contributions to common joint injuries and pathologies.
The joints of the human body largely govern the directional motion capabilities of body segments. The anatomical structure of a given joint, such as the uninjured knee, varies little from person to person; as do the directions in which the attached body segments, such as the thigh and lower leg, are permitted to move at the joint. However, differences in the relative tightness or laxity of the surrounding soft tissues result in differences in joint ranges of movement. This chapter discusses the biomechanical aspects of joint function, including the concepts of joint stability and joint flexibility, and related implications for injury potential.
Anatomists have categorized joints in several ways, based on joint complexity, the number of axes present, joint geometry, or movement capabilities. Because this book focuses on human movement, a joint classification system based on motion capabilities is presented.
The mid-radioulnar joint is an example of a syndesmosis, where fibrous tissue binds the bones together. Courtesy of McGraw-Hill Companies, Inc.
The sternocostal joints are examples of synchondroses, wherein the articulating bones are joined by a thin layer of hyaline cartilage. Courtesy of McGraw-Hill Companies, Inc.