Leg numbness without back pain: The cause may be a lumbar nerve issue

It can be disconcerting if you experience tingling or pulling sensations from your buttocks to your calves and toes, even though there is no pain in the back itself. Many patients believe that because their back does not hurt, it cannot be a back problem, but in reality, leg pain often occurs due to issues with the lumbar nerves.

Dr. Lee Jae-uk, an orthopedic specialist appearing on the Uihak Channel Biondwi video, stated that he frequently encounters patients in outpatient clinics who complain only of leg numbness without back pain. He explained that while patients say their buttocks or legs hurt, they often claim there is no pain in their back at all, leading them to doubt a diagnosis involving a back issue.

The cause of 'radiating pain' where only the legs are numb without back pain

Dr. Lee Jae-uk explained this through the case of a female patient in her 50s. This patient had been experiencing pulling sensations in her right buttocks, back, and down to her calves for several weeks, but had no back pain at all. Physical examinations and X-rays were performed to check for hip joint diseases, but there were no issues with the hip joint itself. This is a typical pattern of 'radiating pain,' where a problem in the lumbar nerves causes pain to descend toward the legs.

In fact, in the case of a female patient in her 60s, she visited the clinic complaining of knee pain, but examination results showed that her knee arthritis was in its early stages, and 'spondylolisthesis'—where the 4th and 5th lumbar vertebrae are misaligned—was confirmed on the lumbar X-ray. As such, if there is spondylolisthesis or stenosis, pain can be transmitted to the knees or legs as nerves are compressed, even if there is no back pain.

Nerve block: A fundamental treatment process, not just a simple analgesic

In cases where radiating leg pain occurs due to lumbar nerve issues, the video introduced the treatment process through a 'nerve block.' Many patients misunderstand a nerve block as simply an analgesic injection to soothe pain, but it is closer to a treatment that addresses the cause.

When a nerve is compressed or irritated, inflammation and swelling occur around the nerve, and the nerve itself becomes sensitive. A nerve block works by accurately injecting medication around the problematic nerve to wash away the accumulated inflammation around the nerve, remove swelling, and calm the excitation of the sensitized nerve. In fact, the effectiveness can be confirmed through cases where patients complaining of radiating pain saw improvement in their buttock and calf pain after receiving a nerve block in the lumbar area.

Lumbar injuries in daily life and symptoms by type

Dr. Lee Jae-uk classified the types of patients visiting the hospital into three categories. The first is the most common 'only the back hurts,' which is mainly caused by damage to muscles, ligaments, joints, or discs. The second is 'the back hurts and the legs are numb,' and the third is today's topic, 'the back does not hurt but only the legs are numb.'

In particular, back pain often occurs during daily activities without any special accident. In the majority of cases, people unknowingly injure their backs while lifting heavy objects, bending over, sitting for long periods, or during exercises like deadlifts or squats at the gym. Patients often say, "I have never injured my back," but most back injuries occur during routine movements such as sitting down and standing up, or bending and twisting the waist, without being noticed.

Additionally, regarding a viewer's question about a case where "the back hurts when sitting for a long time, and the legs become numb when walking, causing one to sit down," Dr. Lee explained the difference between the two symptoms. Back pain when sitting for a long time is a common symptom that occurs as the strength of the muscles around the back gradually decreases, but the symptom of having to sit down due to leg numbness while walking is a typical symptom of stenosis called 'intermittent neurogenic claudication.' Since this is a symptom that appears when nerves are severely compressed, a detailed examination may be required.