An inversion injury, the most common cause of
ankle sprains, occurs when the ankle rolls outward and
the foot turns inward. It results in stretching and tearing of the ligaments on
the outside of the ankle. In an eversion injury, the ankle rolls inward and the
foot turns outward, damaging the ligaments at the inside of the ankle. If the
foot is forced up, or the leg twists forcefully while the foot is planted, the
ligaments that join the leg bones together above the ankle may be injured. This
is called a high ankle sprain. It can happen either alone or along with an
inversion or eversion sprain. See a picture of
types of ankle sprains.
In an ankle sprain, damage to the ligament varies from simply
stretched or slightly torn to completely torn. Your doctor will grade your
Grade I is stretching or
slight tearing of the ligament with mild tenderness, swelling, and stiffness.
The ankle feels stable, and it is usually possible to walk with minimal
Grade II is a larger but incomplete
tear with moderate pain, swelling, and bruising. Although the ankle sometimes
feels stable, the damaged areas are tender to the touch, and walking is
painful. See a picture of a
grade II ankle sprain.
Grade III is a
complete tear of the affected ligament or ligaments with severe
swelling and bruising. The ankle is unstable and may feel "wobbly." Walking is
usually not possible because the ankle gives out and there is intense pain,
although initial pain may quickly subside.