A sprain is an injury to a ligament, the tough, fibrous tissue that connects bones to other bone. Ligament injuries involve a stretching or a tearing of this tissue.

A strain is an injury to either a muscle or a tendon, the tissue that connects muscles to bones. Depending on the severity of the injury, a strain may be a simple overstretch of the muscle or tendon, or it can result in a partial or complete tear.

Sprains
A sprain typically occurs when people fall and land on an outstretched arm, slide into base, land on the side of their foot, or twist a knee with the foot planted firmly on the ground. This results in an overstretch or tear of the ligament(s) supporting that joint.

Although sprains can occur in both the upper and lower parts of the body, the most common site is the ankle. Ankle sprains are one of the most common injuries in professional and recreational sports and activities.

Most ankle sprains happen when the foot abruptly turns inward (inversion) or outward (eversion) as a person runs, turns, falls, or lands after a jump. One or more of the lateral ligaments are injured. Wrist sprains are common when people fall and land on an outstretched hand.

Signs and Symptoms of Sprains
The usual signs and symptoms of a muscle sprain include pain, swelling, bruising, and the loss of functional ability (the ability to move and use the joint). Sometimes people feel a pop or tear when the injury happens. However, these signs and symptoms can vary in intensity, depending on the severity of the sprain.

 

Sprain Severity

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• Grade I Sprain: A grade I (mild) sprain causes overstretching or slight tearing of the ligaments with no joint instability. A person with a mild sprain usually experiences minimal pain, swelling, and little or no loss of functional ability. Bruising is absent or slight, and the person is usually able to put weight on the affected joint.
• Grade II Sprain: A grade II (moderate) sprain causes partial tearing of the ligament and is characterized by bruising, moderate pain, and swelling. A person with a moderate sprain usually has some difficulty putting weight on the affected joint and experiences some loss of function. An x-ray or MRI may be needed.
• Grade III Sprain: A grade III (severe) sprain results in a complete tear or rupture a ligament. Pain, swelling, and bruising are usually severe, and the patient is unable to put weight on the joint. An x-ray is usually taken to rule out a broken bone. This type of a muscle sprain often requires immobilization and possibly surgery. It can also increase the risk of an athlete having future muscles sprains in that area.

When diagnosing any sprain, the doctor will ask the patient to explain how the injury happened. The doctor will examine the affected joint, check its stability and its ability to move and bear weight.

Strains
A strain is caused by twisting or pulling a muscle or tendon. Strains can be acute or chronic. An acute strain is caused by trauma or an injury such as a blow to the body; it can also be caused by improperly lifting heavy objects or overstressing the muscles. Chronic strains are usually the result of overuse - prolonged, repetitive movement of the muscles and tendons.

Two common sites types of muscle strain are back strains and hamstring strains. Tendonitis (inflammation of a tendon) is another common type of muscle strain. Contact sports such as soccer, football, hockey, boxing, and wrestling put people at risk for strains. Gymnastics, tennis, rowing, golf, and other sports that require extensive gripping can increase the risk of hand and forearm strains. Elbow strains sometimes occur in people who participate in racquet sports, throwing, and contact sports. The two most common elbow strains are tennis elbow (lateral epicondylitis) and golfer’s elbow (medial epicondylitis).

Signs and Symptoms of Strains
Typically, people with a strain experience pain, muscle spasm and muscle weakness. They can also have localized swelling, cramping, or inflammation and, with a more severe strain, some loss of muscle function. Patients typically have pain in the injured area and general weakness of the muscle when they attempt to move it. Severe strains that partially or completely tear the muscle or tendon are often very painful and disabling.

Strain Severity
Strains are categorized in a similar manner to sprains:

• Grade I Strain: This is a mild strain and only some muscle fibers have been damaged. Healing occurs within two to three weeks.
• Grade II Strain: This is a moderate strain with more extensive damage to muscle fibers, but the muscle is not completely ruptured. Healing occurs within three to six weeks.
• Grade III Strain: This is a severe injury with a complete rupture of a muscle. This typically requires a surgical repair of the muscle; the healing period can be up to three months.

When To See a Doctor for a Sprain or Strain

• You have severe pain and cannot put any weight on the injured joint.
• The area over the injured joint or next to it is very tender when you touch it.
• The injured area looks crooked or has lumps and bumps that you do not see on the uninjured joint.
• You cannot move the injured joint.
• You cannot walk more than four steps without significant pain.
• Your limb buckles or gives way when you try to use the joint.
• You have numbness in any part of the injured area.
• You see redness or red streaks spreading out from the injury.
• You injure an area that has been injured several times before.
• You have pain, swelling, or redness over a bony part of your foot.