A sprained ankle is a very common injury. Approximately 25,000 people
experience it each day. A sprained ankle can happen to athletes and
non-athletes, children and adults. It can happen when you take part in
sports and physical fitness activities. It can also happen when you
simply step on an uneven surface, or step down at an angle.
The ligaments of the ankle hold the ankle bones and joint in
position. They protect the ankle joint from abnormal
movements-especially twisting, turning, and rolling of the foot.
A ligament is an elastic structure. Ligaments usually stretch
within their limits, and then go back to their normal positions. When a
ligament is forced to stretch beyond its normal range, a sprain occurs. A
severe sprain causes actual tearing of the elastic fibers.
Ankle sprains happen when the foot twists, rolls or turns beyond
its normal motions. A great force is transmitted upon landing. You can
sprain your ankle if the foot is planted unevenly on a surface, beyond
the normal force of stepping. This causes the ligaments to stretch
beyond their normal range in an abnormal position.
Diagnosis
See your doctor to diagnose a sprained ankle. He or she may order
X-rays to make sure you don't have a broken bone in the ankle or foot. A
broken bone can have similar symptoms of pain and swelling.
The injured ligament may feel tender. If there is no broken bone,
the doctor may be able to tell you the grade of your ankle sprain based
upon the amount of swelling, pain and bruising.
The physical exam may be painful. The doctor may need to move your
ankle in various ways to see which ligament has been hurt or torn.
If there is a complete tear of the ligaments, the ankle may become
unstable after the initial injury phase passes. If this occurs, it is
possible that the injury may also cause damage to the ankle joint
surface itself.
The doctor may order an MRI (magnetic resonance imaging) scan if he
or she suspects a very severe injury to the ligaments, injury to the
joint surface, a small bone chip or other problem. The MRI can make sure
the diagnosis is correct. The MRI may be ordered after the period of
swelling and bruising resolves.
The amount of pain depends on the amount of stretching and tearing
of the ligament. Instability occurs when there has been complete tearing
of the ligament or a complete dislocation of the ankle joint.