Lumbar Back Sprains and Strains
Most people will experience back pain during their lifetime. Some patients fear the worst, especially when pain is acute or severe. The most common cause of back pain is sprain or strain, although pain can be so intense and severe that the cause may be attributed to vertebral fracture, disc disorder, or tumor.
Sprains and strains often result from excessive physical demands on the back. Lifting something too heavy, a sudden fall, car crash, or sports injury can cause soft tissues (ligaments, muscles, tendons) to stretch too much.
Diagnosing a specific pain generator in cases of acute back pain is a difficult challenge, and often guided more accurately by an accurate history and examination than any imaging studies. The case of ligamentous strain or muscle sprain is a good example of a condition that will not be specifically represented by MRI or other imaging modalities. Therefore, in the absence of neurologic findings or pain persistent longer than one month, radiographic evaluation is rarely useful.
How your spine is designed to help prevent sprains and strains
The spine includes vertebrae (bones), discs (cartilaginous pads or shock absorbers), the spinal cord and nerve roots (neurological wiring system), and blood vessels (nourishment). Ligaments link bones together, and tendons connect muscles to bones and discs. The ligaments, muscles, and tendons work together to manage external forces the spine encounters during movement, such as bending forward and lifting.
Soft tissue injuries
Sprains and strains are similar disorders that affect different soft tissues in the spine.
- Sprains affect ligaments
- Strains affect muscles, tendons, or muscle-tendon combinations
Role of supporting structures
- Ligaments are strong flexible bands of fibrous tissue. Although ligaments are resistant to being stretched, they do allow some freedom of movement.
- Muscle is made up of individual and segmental strands of tissue. When back muscles encounter excessive external force, individual strands can stretch or tear while the rest of the muscle is spared injury.
To illustrate a sprain, consider what happens when someone lifts something heavy. Initially muscles are recruited to manage the load. When the load or force exceeds the muscles' ability to cope, the force is shared with the ligaments. When a ligament is stressed beyond its strength, it can tear.
Local tissues swell when ligaments, muscles, tendons, or combinations become overstretched, overused, or torn. Swelling causes pain, tenderness, and stiffness; swelling serves to protect the injured back by restricting movement; similar to a splint on a broken leg.
About 90% of ligament strains and muscle sprains will improve spontaneously within four weeks. The goal of therapy is prevention of recurrence. Posture, ergonomic principles, and smoking cessation are fundamental to prevention. Furthermore, cardiovascular fitness is an independent factor that predicts spinal health, and working toward improving cardiovascular fitness is an important therapeutic intervention.