Ankle Sprain
Cause
Ankle sprains occur when ligaments that connect the bones in the foot, ankle, and lower leg stretch or tear.
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 a "high" ankle sprain, a less common type of inversion injury, the ligaments at the top and outside of the ankle are also torn, increasing the sprain's severity and healing time.
In an eversion injury, the ankle rolls inward and the foot turns outward, damaging the ligaments at the inside of the ankle.
See an illustration of eversion and inversion injuries
.
Damage to the ligament varies from simply stretched or slightly torn to completely torn. Your doctor will grade your sprain accordingly.
- 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 pain.
- 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.
- Grade III is a complete tear of the affected ligament or ligaments with severe swelling and bruising
 Go to previous section |  Go to top of page |  Go to next section |
| Author: | Douglas Dana Amy Fackler, MA | Last Updated: March 30, 2006 |
| Medical Review: | William M. Green, MD - Emergency Medicine Adam Husney, MD - Family Medicine H. Michael O'Connor, MD - Emergency Medicine | |
 | ||
