|
Knee Anatomy and Function
The knee is essentially made up of four bones. The femur,
which is the large bone in your thigh, attaches by ligaments
and a capsule to your tibia. Just below and next to the
tibia is the fibula, which runs parallel to the tibia. The
patella, or what we call the knee cap, rides on the knee
joint as the knee bends.

When the knee moves, it does not just bend and straighten,
or, as it is medically termed, flex and extend. There is
also a slight rotational component in this motion. This
component was recognized only within the last 50 years,
which may be part of the reason people have so many unknown
injuries. The knee muscles which go across the knee joint
are the quadriceps and the hamstrings.
The quadriceps muscles are on the front of the knee, and
the hamstrings are on the back of the knee. The ligaments
are equally important in the knee joint because they hold
the joint together. You may have heard of people who have
had ligament tears. Problems with ligaments are common. In
review, the bones support the knee and provide the rigid
structure of the joint, the muscles move the joint, and the
ligaments stabilize the joint.
The
knee joint also has a structure made of cartilage, which is
called the meniscus or meniscal cartilage. The meniscus is a
C-shaped piece of tissue which fits into the joint between
the tibia and the femur. It helps to protect the joint and
allows the bones to slide freely on each other. There is
also a bursa around the knee joint. A bursa is a little
fluid sac that helps the muscles and tendons slide freely as
the knee moves.
To function well, a person needs to have strong and flexible
muscles. In addition, the meniscal cartilage, articular
cartilage and ligaments must be smooth and strong. Problems
occur when any of these parts of the knee joint are damaged
or irritated.
|