The back is a complex structure of bone and muscle, supported by cartilage, tendons, and ligaments, and fed by a network of blood vessels and nerves. The back—especially the lumbar, or lower back—bears much of the body’s weight during walking, running, lifting, and other activities. It makes sense, then, that injuries to the lower back—such as strains and sprains—are common.

What is a strain?

A strain is an injury to either a muscle or tendon. Tendons are the tough, fibrous bands of tissue that connect muscle to bone. With a back strain, the muscles and tendons that support the spine are twisted, pulled, or torn.

What is a sprain?

A sprain is the stretching or tearing of a ligament. Ligaments are the fibrous bands of tissue that connect two or more bones at a joint and prevent excessive movement of the joint.

How common are back strains and sprains?

Strains and sprains are very common injuries. Next to headaches, back problems are the most common complaint to health care professionals.

What causes a back strain or sprain?

Twisting or pulling a muscle or tendon can result in a strain. It can also be caused by a single instance of improper lifting or by overstressing the back muscles. A chronic strain usually results from overuse involving prolonged, repetitive movement of the muscles and tendons.

A sprain often results from a fall or sudden twist, or a blow to the body that forces a joint out of its normal position. All of these conditions stretch one or more ligaments beyond their normal range of movement, causing injury.

In addition, there are several factors that put a person at greater risk for a back strain or sprain, including excessively curving the lower back, being overweight, having weak back or abdominal muscles, and/or tight hamstrings (muscles in the back of the thighs). Playing sports that involve pushing and pulling—such as weightlifting and football—also increases the risk of a low-back injury.

What are the symptoms of a back strain or sprain?

Symptoms of a strain or sprain include:

  • Pain that worsens with movement
  • Muscle cramping or spasms (sudden uncontrollable muscle contractions)
  • Decreased function and/or range of motion of the joint (difficulty walking, bending forward or sideways, or standing straight)

In some cases, the person may feel a pop or tear at the time of the injury.