At the conclusion of this chapter, the student should be able
- 1. Classify joints according to structure and explain
the relationship between a joint structure and its capacity for
- 2. Explain how the schedule of ossification of epiphyseal
cartilage is related to the nature of activities suitable for different
- 3. Name the factors that contribute to joint range of motion
and stability and explain the relationship that exists between range
of motion and stability.
- 4. Assess a joint’s range of motion, evaluate the
range, and describe desirable procedures for changing it when indicated.
- 5. Name and define the orientation positions and planes of
the body and the axes of motion.
- 6. Demonstrate and name fundamental movement patterns using
correct movement terminology.
- 7. Isolate and name single joint actions that are part of
- 8. Perform an anatomical analysis of the joint actions and
planes of motion for a selected motor skill.
It is customary—especially for students of human movement
and exercise—to begin the study of anatomy with a detailed
study of the bones, then to proceed to the joints, and then to the
muscles. This path of investigation sometimes dampens the enthusiasm
of students, whose chief focus of interest is movement. Therefore,
this chapter and the next emphasize the concept of the total musculoskeletal
system as a mechanism for motion. It is hoped that by using this
concept the student will find the study of the structural elements
of this system more meaningful.
As the phrase implies, the musculoskeletal framework is an arrangement
of bones and muscles. Adjacent bones are attached to one another
by joints, which provide for the motion of the articulating bones,
and the muscles that span the joints provide the force for moving
the bones to which they are attached. Mechanically, the total bone–joint–muscle
structure is an intricate combination of levers that makes possible
a great number of coordinated movements, ranging from the small hand
and finger motions used in assembling a television set or playing
the piano to the total body movements of a swimmer or a pole vaulter.
Any single one of the levers involved in such movements is relatively
In physics we are taught that a lever is defined as a rigid bar
that turns about a fulcrum (fixed axis or pivot) when force is applied
to it at some specific point. An anatomical lever, therefore, is
simply a bone that engages in an angular or turning type of movement
when a force is applied to it. This force may be the contracting
force of a muscle attached to the bone, or it may be an external force
such as gravity or an external weight. If the force is muscle, it
is always a pulling force, because muscles, being flexible, are
unable to push; they can only pull. If the force is external, such
as when a weight is too heavy to ...