Skip to Main Content

INTRODUCTION

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.

CONNECT RESOURCES

Log on to Connect for access to these additional resources:

  • Online Lab Manual

  • Chapter lecture PowerPoint presentation

  • Chapter quizzes

  • Additional chapter resources

  • Web links for study and exploration of chapter-related topics

©Vaara/Getty Images

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.

The mid-radioulnar joint is an example of a syndesmosis, where fibrous tissue binds the bones together. ©McGraw Hill

JOINT ARCHITECTURE

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 sternocostal joints are examples of synchondroses, wherein the articulating bones are joined by a thin layer of hyaline cartilage. ©McGraw Hill

Immovable Joints

  1. Synarthroses (immovable) (syn = together; arthron = joint): These fibrous joints can attenuate force (absorb shock) but permit little or no movement of the articulating bones.

    1. Sutures: In these joints, the irregularly grooved articulating bone sheets mate closely and are tightly connected by fibers that are continuous with the periosteum. The fibers begin to ossify in early adulthood and are eventually replaced completely by bone. The only example in the human body is the sutures of the skull.

    2. Syndesmoses (syndesmosis = held by bands): In these joints, dense fibrous tissue binds the bones together, permitting extremely limited movement. Examples include the coracoacromial, mid-radioulnar, mid-tibiofibular, and inferior tibiofibular joints.

Note the hyaline cartilage disc separating the bones of the pubic symphysis, typical of a symphysis joint. ©McGraw Hill

Fibrocartilage is present in A. the intervertebral discs between adjacent vertebrae and B. the symphysis pubis that separates ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.

  • Create a Free Profile