The L3-L4 spinal segment, positioned in the middle of the lumbar spine, plays an important role in supporting the weight of the torso. The nerves, muscles, and other soft tissues also aid with such processes as knee extension and foot motion.
A problem at this level of the spine is most likely to result in pain and possibly neurological symptoms that are felt in the front of the thigh, and possibly the front of the knee, shin, and foot. These symptoms are different from symptoms caused by pathology at the L4-L5 or L5-S1 levels, as involvement at those lower levels of the spine are more likely to cause pain, tingling, or weakness on the outside or sole of the foot.
The lower the position of a vertebra in the lumbar spine, the more weight it will hold. The more weight a vertebra supports, the more potential for injury. While the L3-L4 segment is less likely to be damaged than L4-L5 below it, it can still sustain damage easily from either impact injury or natural degeneration.
Pain in the L3-L4 segment can commonly arise from:
- The disc can become herniated, resulting in unwanted contact between the disc and the nerve and frequently causing pain.
- The facet joints of the segment can become enlarged, narrowing the open spaces of the spine and compressing spinal nerve roots.
- The disc can degenerate naturally over time, which changes the motion of the disc and usually results in stiffness and—much less commonly—tingling in the leg or pain.
In This Article:
- All About the L3-L4 Spinal Segment
- Lumbar Spine Anatomy Video
Causes of L3-L4 Pain
Pain can be caused in the L3-L4 spinal segment due to lower lumbar problems such as:
- Spondylolisthesis of the L3-L4 segment. Though rare in the L3-L4 segment, spondylolisthesis can occur if the L3 vertebra slips forward or backward over the edge of L4. This condition is almost always degenerative, resulting from overuse. In rare instances, spondylolisthesis can be isthmic, occurring when a bone connecting spinal joints develops a small fracture allowing one vertebral body to move forward over another.
- Herniation of the L3-L4 disc. Roughly 5% of lower back disc herniations involve the L3-L4 segment. Usually this will involve compression of the nerve root below the herniated disc, but can also manifest as compression of the nerve root above the disc (far lateral disc herniation). Typically pain will occur throughout the anterior (front) thigh with sensory limitation in the shin or medial knee.
- Osteoarthritis. Spinal osteoarthritis of the L3-L4 segment can result from the natural degradation of the cartilage between the facet joints over time. Pain will usually occur near the joint but may refer into the front of the legs.
- Stenosis. Lumbar stenosis involves compression of the spinal nerve roots in the lower back due to a narrowing of the spinal canal. Pain, numbness, tingling, or weakness may be noted in the upper legs.
- Degenerative disc disease. Not actually a disease at all, this condition occurs when a disc has degenerated for any number of reasons. This condition usually causes no symptoms, but when it does pain or tingling may be noted in the affected areas.
Treatment of pain in the L3-L4 segment will be dictated by the underlying diagnosis of the cause of the patient’s pain and the severity of the condition. While many injuries or ailments can be treated with physical therapy or manual manipulation and other non-invasive procedures, others will warrant more interventions treatment steps such as spinal injections.