The back is a remarkable combination of strength, flexibility and sensitivity comprised of bones, ligaments, tendons, muscles and nerves. However, some motion in the spine, even micro-motion at a specific spinal segment, can cause pain. The portions of the spine that are able to move are called motion segments and it is important to understand that motion segments can cause pain in the lower back. You should also understand how the spine can be treated to reduce or remove that pain.
There are many different types of motion that can indicate the problem in your spine causing the pain:
- Movement causes pain to radiate down the lower back and legs
- Any movement causes pain in the lower back and hip area, worst in the morning or late evening
- Pain or numbness in the legs when walking
- Pain gets worse when sitting or bending
The most common reason motion will cause back or neck pain has nothing to do with the spinal structure at all. The muscles or ligaments surrounding the spine in the back or neck can become over-stretched or even torn. This causes inflammation and pain while the body tries to limit motion while it heals. Learn more with Low Back Pain from Muscle Strain and Neck Strain: Causes and Remedies.
Spinal Anatomy and Herniated Discs
Of the four major regions of the spine, the lumbar spine (lower back) has a lot of motion and carries all the weight of the torso, making it the most frequently injured area of the spine. While the vast majority of episodes of lower back pain are caused by muscle strain, other structures in the lower back can also cause pain. For more on spinal anatomy, see Spinal anatomy and back pain and Spine anatomy illustrations.
The motion in the lower back is divided between five vertebral motion segments (each of which are comprised of 2 cartilage-covered facet joints and a disc), although a disproportionate amount of the motion is in the lower segments (L3-L4, L4-L5, L5-S-1).
The two lowest discs (L4-L5 and L5-S1) take the most strain and are the most likely to become herniated. This can cause pain and possibly numbness that radiates through the leg and down to the foot (sciatica). For more on sciatica, see Sciatica and the sciatic nerve.
Cartilage Breakdown Creates Frictional Pain in Lumbar Spine Osteoarthritis
Spinal arthritis is relatively common and is most likely to occur in people over age fifty. Spinal osteoarthritis is the mechanical breakdown of the cartilage between the aligning facet joints in the back portion (posterior) of the spine. The facet joints (also called vertebral joints or zygophyseal joints) become inflamed and progressive joint degeneration creates more frictional pain. Back motion and flexibility decrease in proportion to the progression of back pain induced while standing, sitting and even walking.
Symptoms include stiffness and pain in the lower spine and sacroiliac joint (between the spine and pelvis), which are typically most pronounced in the morning and worsen again later in the day. Pain is decreased during the day as the person's normal movements stir the fluid lubricant of the joints. Lower back pain commonly may radiate to the pelvis, buttocks or thighs and sometimes to the groin. See also Spinal arthritis complete treatment guide.
Additional Pain Can Result From Bone Spurs or Synovial Cysts
With osteoarthritis, bone spurs (small irregular growths on the bone, also called osteophytes) typically form on the facet joints and are a response to joint instability (from the degeneration). Bone spurs can be a normal part of aging and do not directly cause pain, but may become large enough to cause irritation or entrapment of nerves passing through spinal structures, and may result in diminished room for the nerves to pass (stenosis). Most cases will produce pain (and perhaps numbness and tingling) into the legs with walking, and the pain will be relieved with sitting. Read more in Symptoms of bone spurs and Spinal stenosis symptoms and diagnosis.
Over time, degeneration of the facet joints in the lower back can result in formation of a fluid-filled sac called a synovial cyst. These cysts are benign in and of themselves, but if they put pressure on the spinal canal they can, like bone spurs, cause symptoms of spinal stenosis. See Pain from a synovial cyst in the lumbar spine.
A Painful Disc Causes Low Back Pain in Lumbar Degenerative Disc Disease
Degenerative disc disease refers to a syndrome in which a painful disc causes chronic low back pain, typically in people 30 to 40 years of age. With symptomatic degenerative disc disease, the condition creates excessive micro-motion at a vertebral level and leads to pain.Common symptoms of degenerative disc disease include:
- The low back pain generally worsens with sitting.
- Certain types of activity usually worsen the low back pain, especially bending, lifting and twisting.
- Walking, and even running, may actually feel better than prolonged sitting or standing.
- Patients generally feel better if they change positions frequently, and lying down is usually most comfortable.
- For more, see What is degenerative disc disease?.
Most Motion-Painful Segment Conditions Respond Well to Conservative Care
There are a number of non-surgical treatments available to help successfully manage the low back pain and occasional episodes of more severe pain associated with painful motion segments. Treatment plans typically include exercise and physical therapy, healthier lifestyle choices (e.g. weight loss, posture, ergonomic improvements), medications for pain and/or inflammation (including injections) and spinal manipulation. For the full range of condition-specific treatment options, see Low back pain and degenerative disc disease treatments.
In cases of continual severe pain and/or activity limitations due to painful motion segments, surgery may be an option. For example, fusion surgery can help alleviate pain because it stops the motion at the painful motion segment. However, surgery is not recommended for everyone. Learn if surgery is right for you with Surgery for spinal arthritis, and Lumbar spine fusion surgery for degenerative disc disease.
The key to pain reduction from any lower back condition is getting an accurate diagnosis of the pain generator and beginning proactive treatment. With a better understanding of spinal anatomy and the pain associated with motion segment disorders, you can better describe your symptoms and help your doctors more accurately identify the specific cause of the pain. In addition to the resources referenced above, articles like Preparing to meet with a spine surgeon or spine specialist could help you work with your doctor to more quickly develop an appropriate treatment plan for the segment of your spine creating pain during motion.