Epidemiologic studies have shown that more than 80% of people have a history of low back pain in their lifetime. Most of these low back pains occur after the age of 30, and the incidence increases with age. The post-30 age group is the creative stage of life, so it is clear that low back pain can have a significant impact on a person’s daily life. Many episodes of low back pain are self-limiting, meaning they resolve without treatment. However, for some people, low back pain can become chronic, with degenerative changes in the lumbar spine due to ageing being the main cause. As a result, chronic low back pain is one of the main causes that plague and affect the daily lives of middle-aged and elderly people. What causes your chronic low back pain? The main cause of chronic low back pain is degenerative changes in the lumbar spine. To understand the mechanism by which degenerative changes in the lumbar spine cause low back pain, it is necessary to understand the anatomy of the lumbar spine. The lumbar spine consists of five vertebrae, and in order to better understand how the lumbar spine interacts with each other, we present a lumbar spine segment. A lumbar segment consists of two vertebrae, the intervertebral disc between the two vertebrae, and two nerve roots leaving the segment on one side. The vertebrae are the bony parts of the spine and their function is to provide support and protect the spinal cord. When the vertebrae are stacked on top of each other, they form a column (in the front) and a bony canal-the spinal canal (in the back)-which consists of individual rings with the spinal cord and nerves traveling in between. The small joints keep the vertebrae connected like a chain, and they provide a dynamic connection between each vertebra. As we twist or bend, the small joints move and slide, just like other joints in the body, such as the shoulder joint. Between the small joints of the upper and lower vertebrae is where the nerve roots pass through, called the radicular canal. The small joints can be affected by degenerative arthritis and degenerate, which can cause narrowing of the nerve root canal. The intervertebral disc is between each of the two vertebrae; it is actually a large, circular ligament that connects each vertebra. In the center of this circular ligament is the elastic, jelly-like nucleus pulposus (NPS), and what is commonly referred to as a lumbar disc herniation is actually a herniation of the NPS. It is helpful to understand the lumbar segments in cross-section. If we look at the intervertebral disc from a cross-section, it is composed of two parts: the fibrous ring connecting the vertebrae on the outside, and the nucleus pulposus on the inside, which is as hard as crab meat and has the function of absorbing shock. The nerve roots are responsible for connecting the lower extremities to the brain. Nerve roots can sometimes cause low back pain, which occurs when the nerve root is agitated or pinched by a disc or bone spur. Many causes of lower back pain are the result of damage or degeneration of the meshed discs; degeneration is a process of wear and tear (like jeans getting old and worn out). As we use our lower backs every day, the discs are subjected to different types of forces, and the discs act like a shock absorber. Bending that puts pressure on the discs causes them to bulge out toward the spinal canal and nerve roots. In order to bend, the small joints must move, and twisting and bending at the same time is the greatest compression of the spine, especially the discs. The earliest change that occurs in the intervertebral disc is the partial breakdown of the annulus fibrosus of the intervertebral disc. Remember that the annulus fibrosus is a large round ligament, and repair of the ruptured nucleus pulposus occurs through scar formation like any other ligament. Multiple ruptures of the nucleus pulposus are repaired through scar tissue resulting in the beginning of degeneration of the disc. What happens when the inter-disc begins to degenerate? As the disc degenerates, the nucleus pulposus loses some of its own water, it hardens and loses its shock absorber function, and this process continues until the disc collapses. As the body responds to the degeneration, bone spurs will form, which are thought to be the result of hypermobility of the lumbar segments, and eventually bone spurs form around the nerve roots. One of the most dramatic injuries in the lumbar spine is a herniated disc. In the injury, the ruptured annulus fibrosus allows the nucleus pulposus to squeeze into the spinal canal, and if the nerve root is compressed by the tissue of the meshed disc, pain, numbness, and decreased muscle strength in that innervated area can occur. Also not only pressure from the herniated disc can cause symptoms, but the inflammatory response caused by the nucleus pulposus tissue that squeezes the nerve root can cause pain, and lumbar segmental instability can cause low back pain. Remember the structure of the lumbar segments we described? Segmental instability is the movement of one vertebra over another. These movements often provoke or squeeze the nerve roots that come out of the intervertebral foramina. Excessive spinal motion can also agitate the small joints, which can cause mechanical pain due to arthritis. Spasms can also occur in the muscles that support the spine, and the spasming muscles try to stop the spinal movement that is causing the pain, like a cramp in your leg or stomach, which becomes quite painful if it lasts for a long period of time. In the later stages of degeneration, bone spurs caused by degeneration can cause spinal stenosis, where the spinal canal becomes quite small and compresses the nerve roots causing pain and dysfunction of the leg muscles. Spinal stenosis usually occurs after years of wear and tear and is common in the elderly. Spinal stenosis refers to the narrowing of the spinal canal throughout the lumbar spine, while neural radicular stenosis refers to the narrowing of the nerve pathways caused by the development of bone spurs on the small joints and herniated discs in the same segment. Sometimes due to degeneration and segmental instability, the vertebrae can slip anteriorly and compress the nerves, which is known as lumbar spondylolisthesis. Although degenerative changes in the lumbar spine are the main cause of chronic low back pain, there are other conditions that cause and aggravate the degeneration of the lumbar spine and chronic low back pain, such as prolonged heavy physical labor, poor posture in daily life (keeping the lumbar spine in a stooped state for a long period of time or lifting heavy objects while stooping, etc.), chronic injuries and strains, and direct injuries. Self-determination, protection and treatment of chronic low back pain So how do you determine for yourself what causes your low back pain? Now let’s understand the symptoms of lower back and leg pain using the part of the anatomy we know. Lower back pain can be categorized into two types: mechanical type pain and pressure pain. Mechanical types of pain are caused by an inflammatory response due to agitation or degeneration of the discs, small joints, ligaments, and muscle groups in the back, and a common cause of mechanical types of pain is degeneration and instability of the intervertebral discs. A typical muscle sprain or lumbar sprain is also a cause of mechanical type pain. Mechanical type pain usually starts in the lower back and can also disperse to the hips and thighs, but rarely spreads below the knee. Pressure pain (neurogenic pain) usually occurs when a nerve root is agitated or compressed, and a common cause of pressure pain is a herniated disc. The nerves leaving the lower back make up the sciatic nerve, which provides sensation and controls the function of the muscles in the lower extremities. Agitation and compression of the sciatic nerve can interfere with its normal function. One of the earliest symptoms of nerve root compression is numbness in the lower extremities, with pain in the same area often radiating to the knee to the foot, which is commonly referred to as sciatica. This is when the pain is aggravated by bending over, coughing and sneezing. However, sometimes there is compression on the nerve roots exiting the vertebral foramen, such as stenosis, but there is no pain in the back. Finally those nerve-controlled muscles have reduced muscle strength and muscle atrophy. Spinal stenosis can also cause pressure pain. In some people, degeneration of the lumbar spine can lead to narrowing of the spinal canal, the bony conduit through which spinal nerves pass, so that all of the nerve roots that pass through the canal are agitated and don’t work properly. When you’re resting, these nerves may function normally, but if you’re engaged in activity, these nerves need more blood to provide more oxygen. Because the spinal canal is so tight, the blood supply can’t be increased and symptoms occur. One of the symptoms is numbness and pain in both lower limbs. The numbness and pain worsens during activities such as walking, and in severe cases, when walking more than a hundred meters, you can’t continue, and sitting down or squatting can reduce or relieve it. Sometimes the muscle strength of both lower limbs will also decrease, and will be aggravated during activities. This is often referred to as intermittent claudication. The pain caused by lumbar spondylolisthesis is mixed. In the early stages, because the slipped vertebrae are not heavy, the pain caused is mainly mechanical (lumbar pain predominantly), and it is aggravated by stretching the lumbar region backward. In the later stages, segmental instability leads to aggravation of the slip, hyperplasia of the small joints, and hypertrophy of the surrounding ligaments, when the symptoms are similar to those caused by spinal stenosis. In a very small percentage of cases, the herniated disc that enters the spinal canal is too large, and the compression of the cauda equina nerve will result in paralysis of the muscles that control urination and defecation. If you are incontinent, seek medical attention as soon as possible. Based on what has been said above, you can basically approximate the cause of low back pain. As a chronic condition, low back pain can be self-protected and treated. There are two aspects to talk about here. One is protection in daily life, and the other is self-exercise for lumbar spine function. In daily life unless lying down, whether standing or sitting do not make the lumbar spine to maintain a position too long, to do a little forward back movement, the movement should be gentle. Try to avoid bending too long, do not bend down to lift heavy objects, picking things on the ground to bend the knee joint first, then bend down. If more intense low back pain occurs, you have to lie flat on a hard bed, you can put a small pillow on your waist, don’t let your waist hang in the air. For acute episodes of low back and leg pain, you can use a localized ice or hot water bag (plastic or rubber bag with ice or hot water in it). You can also use heat therapy device (such as Zhoulin spectrum instrument or infrared lamp, etc.) to do local heat therapy. You can also take some anti-inflammatory and pain-relieving drugs such as fenbendazole and fuchsin orally. Usually, after bed rest, physical therapy and medication, the symptoms of lumbar and leg pain will be relieved to different degrees. As mentioned earlier, the muscles around the lumbar spine are also very important factors in the development of low back pain. As you know, the lumbar spine is the only skeletal structure that connects the upper and lower body, so the muscles around the lumbar spine, such as the low back muscles and the abdominal muscles, play an important supporting role. Exercising the low back and abdominal muscles to make them strong can reduce segmental instability due to lumbar spine degeneration, thus alleviating the symptoms. There are two ways to exercise the low back muscles. The first: lie flat on the bed, bend your knees and put your feet on the bed, and then force your hips to lift up and leave the bed for about 10 centimeters, at which time you will feel the lumbar back muscles in force. Insist on about 3-5 seconds to put down, so repeat 10 times. Do this method 3 times a day. The second: lie prone on the bed, both upper limbs straight on both sides of the body, the upper body force to lift about 10 centimeters, then you will feel the lumbar back muscles in the force, the same adhere to the 3-5 seconds to put down, so repeated 10 times, according to this method to do 3 times a day. The exercise of the abdominal muscles is to do sit-ups, the same is to do 10 times each time, 3 times a day. Through the above exercise methods, you can get strong muscles to support and protect the lumbar spine, thus reducing and alleviating the occurrence of low back and leg pain. If your low back and leg pain has lasted for 4 to 6 weeks and the above conservative treatments cannot reduce or relieve the pain, you need to go to the hospital. Here I would like to talk about the commonly used imaging methods and their characteristics. The most commonly used tests for diagnosing low back pain are lumbar spine X-rays. x-rays provide information about the bony structure of the lumbar spine, with or without osteophytes, scoliosis, or vertebral body slippage, and power x-rays can provide information about the stability of the spine. x-rays can also rule out low back pain due to a fracture, infection, or malignant tumor. x-rays (lumbar spine frontal and lateral films) are usually the first step in checking the condition of the low back, and they also help to decide whether or not other tests are needed. CT and MRI (Magnetic Resonance Imaging) scans are further tests that use X-rays or electromagnetic waves to cut the lumbar spine into thin slices, one by one, and show the shape of each slice to give us a better understanding of the lumbar spine. the difference between CT and MRI is that CT uses X-rays, which cut across the spine, and is better at showing bony structures than MRI, which uses electromagnetic waves and can cut across and through the spine. On the other hand, MRI uses electromagnetic waves, which can cut the spine crosswise and longitudinally and obtain a large number of diverse images of the spine, which not only enables you to understand the bony structure of the spine, but also allows us to clearly observe the soft tissues such as the nerves and discs. This is why we say that MRI is the best way to examine the lumbar spine. There are other tests such as vertebroplasty, discography, electromyography (EMG) and isotope bone scanning that can provide help in diagnosing the cause of low back pain.