How do sprains happen?

Sprains usually happen when a person falls, twists, or is hit in a way that forces the body out of its normal position.

The most common type of sprain is a sprained ankle. About 25,000 people sprain an ankle every day. Think of a runner who goes over a curb and catches her foot, twisting the ankle, or a baseball player who slides into a base and twists his knee.

Wrist and thumb sprains are also common, particularly in sports like skiing, where it’s not unusual to fall and land on an outstretched palm.

How do strains happen?

Athletes in contact sports, like football, hockey, and boxing, have the biggest chance of strains. Even in noncontact sports like tennis, golf, or rowing, doing the same motions over and over can lead to strains of the hand and forearm.

These injuries can happen when you work out at the gym, or they can happen at home or the workplace, especially if you do a lot of heavy lifting.

How can you tell the difference?

The signs of most sprains or strains are very similar: pain and inflammation, and sometimes bruising, at the injured area. Depending on how bad the sprain or strain is, the pain may be mild, moderate, or severe.

The worse the sprain or strain, the harder it is to use the affected area. Someone with a mild ankle sprain may just favor that ankle slightly. A more severe ankle sprain may cause much more pain and make it tough or impossible to walk.

If you have a sprain, your doctor may mention its “grade”:

  • Grade I is stretching of the ligament or a very mild tear, with little or no instability at the joint.
  • Grade II is a more serious but still incomplete tear, with some looseness in the joint.
  • Grade III is a completely torn or ruptured ligament. This is not a broken bone, but can feel like one since it’s often impossible to put weight on the joint or use the affected limb because the joint isn’t stable.