Lower back pain affects up to 80% of adults at some point in their lives. Understanding the anatomy and common injuries or conditions that cause lower back pain empowers patients. This guide covers culprits like muscle strains, spinal conditions, and more.
Anatomy of the Lower Back
The lower back, or lumbar spine, is comprised of five vertebrae encased by spinal discs, facet joints, muscles, ligaments, and nerves. This curving structure bears the weight of the upper body while enabling flexibility through the shock-absorbing discs between vertebrae. The facet joints guide back motion, though arthritis often inflames these joints. Delicate nerves exit the spinal cord through the vertebrae; damage to surrounding structures can pinch these nerves.
While the lumbar anatomy allows strength, support and movement, it also leaves the back vulnerable to strain and injury. The vertebrae themselves commonly deteriorate and contribute to pain. Bulging or ruptured discs inflame nerves. Overuse strains muscles and ligaments, requiring recovery time. Overall, maintaining the health of the interdependent spinal components is crucial to preventing the many types of lower back pain.
Common Injuries and Strains
By far the most frequent sources of lower back pain are sprains and strains. Why? The lumbar spine withstands constant stress.
Muscle Strains
Picture lifting a heavy box or twisting to smash a tennis ball. These awkward, forceful movements overextend back muscles. Microtears within muscle fibers spark inflammation and pain. In severe cases, muscles spasm relentlessly.
Factors amplifying strain risks include poor lifting form, weakness, sports, obesity, and aging. Healing mildly strained muscles requires rest, ice, medication, and physical therapy.
Ligament Sprains
Ligaments brace the spine. Falling sideways or forward often sprains these fibrous bands. Meanwhile, repetitive bending, lifting, or twisting overstretches ligaments until small tears appear.
Depending on severity, a back brace, anti-inflammatory medication, and rest help. Physical therapy then rebuilds flexibility and strength.
Traumatic Injury
Car accidents, harsh falls, or violent sports collisions can fracture vertebrae, rupture disks, or tear ligaments. Symptoms include localized bruising, immobility, and excruciating pain. Spinal shock requires prompt emergency treatment to prevent permanent paralysis or disability.
Degenerative Structural Issues
While injury sparks short-term back pain, gradual wear-and-tear underlies most chronic lumbar pain. Key offenders are bulging disks and irritated joints.
Disc Problems
Spongy disks cushion vertebrae but dry out with age. Torn outer rings allow gel-filled centers to protrude, inflaming nearby nerves. Bulging or herniated discs are especially implicated in sciatica pain radiating down the leg.
Rest helps mild cases. Severe slipped disks may need steroid injections or surgery to remove problematic fragments.
Facet Joint Arthritis
These spinal hinges rely on smooth cartilage to glide easily. Osteoarthritis erodes that cushioning. Inflamed, swollen joints transfer pressure onto nerves exiting the spinal canal.
Anti-inflammatories, physical therapy, or joint injections can calm arthritis flareups. As a last resort, radiofrequency ablation deadens irritated nerves.
Spinal Stenosis
Arthritic facet joints or collapsed disks narrow the spinal canal. This squeezes the nerves and blood vessels running through that tunnel. Numbness, cramping, and aching results. Lean forward for relief.
Mild spinal stenosis improves through physical therapy. Severe cases require laminectomy surgery, removing parts of vertebrae to create extra space.
Other Age-Related Factors
While injury sparks short-term back pain, gradual wear-and-tear underlies most chronic lumbar pain. Key offenders are bulging disks and irritated joints.
Osteoporosis
Bone loss from osteoporosis leaves vertebrae brittle. Fragile bones sometimes fracture spontaneously or after minimal strain. These compression fractures tend to affect older women especially. They produce localized pain and height loss as the spine crumbles.
Anti-osteoporosis medication helps strengthen bones. Surgery may stabilize painful compression fractures.
Scoliosis
An abnormal sideways spinal curve, known as scoliosis, forces back muscles to work overtime. Stressed tissues inflame painfully. Altered posture also accelerates disk and joint deterioration.
Custom shoe inserts, exercise, pain relievers, or bracing aid mild scoliosis. Severe cases require spinal fusion to realign vertebrae.
Disease Processes
Beyond wear-and-tear, certain diseases ignite inflammation inside the spine. Suspect them if back pain seems out of proportion to imaging findings.
Inflammatory Arthritis
The immune system goes haywire in arthritis varieties like ankylosing spondylitis and spondylosis. It sparks painful swelling where tendons and ligaments attach onto vertebrae, fusing spinal joints. These arthritis types often strike young adults.
Anti-inflammatory medications combined with physical therapy provide initial treatment. Biologics blocking inflammatory chemicals often follow.
Spinal Infections
Bacteria, fungi, or parasites can spread to intervertebral disks and vertebrae through surgery or preexisting infection. Red flags like fever and neurological symptoms accompany debilitating inflammatory back pain.
Intravenous (IV) antibiotics are the main treatment for most spinal infections. But sometimes the infection forms an abscess or pus-filled cavity around the infected area first. Doctors then have to surgically drain all that gunk before the antibiotics can penetrate and work their magic. After diagnoses, patients should brace themselves for a long haul – it usually takes many months for the spine to fully recover and for all infection symptoms to finally clear up. But stick with the treatment plan and try to be patient (easier said than done, we know). In the end, combining targeted antibiotics and drainage procedures helps overcome stubborn spinal infections. It just takes lots of time for all that inflammation to settle down so the back can heal.
Other Conditions
- Endometriosis: This disorder causing uterine tissue to grow outside the uterus often provokes pelvic pain radiating into the lower back. Symptoms tend to worsen around menstrual periods. Nonsurgical treatments involve pain medication and hormonal therapy.
- Fibromyalgia: Widespread soft tissue pain and tenderness characterize this chronic condition. It frequently causes aches in the lower back and buttocks. Associated issues like fatigue, headaches, depression, and sleep problems help confirm the diagnosis. Low-impact exercise and anti-seizure drugs help some patients.
- Bladder infections: Bacterial infections inside the bladder (cystitis) cause pelvic pain that can extend into the lower back. Other typical symptoms include burning urination, urine frequency/urgency, and fever or chills. Antibiotics quickly cure most bladder infections. Recurrences may demand other treatments.
- Kidney stones: Sharp lower back pain on one side marks the passage of solid crystal aggregates formed inside the kidneys. Intense cramping pain often radiates around to the abdomen and groin. Urinary symptoms like blood in the urine frequently occur too. Pain medication, hydration, diuretics, or lithotripsy break up stubborn stones.
Conclusion
Lower back pain stems from various anatomical and disease-related causes. Pinpointing the precise origin is essential for effective treatment. Don’t simply resign yourself to chronic disability or rely solely on pain medication. Seeking expert guidance facilitates appropriate diagnostics to identify structural, inflammatory or infectious culprits attacking your spine. Custom-tailored treatment plans can then target the root cause for lasting pain relief and restored function.
Written by Dr. Tony Mork
Orthopedic Spine Surgeon
I’m Dr. Tony Mork, MD, a Minimally Invasive Orthopedic Spine Surgery Specialist in Newport Beach, California. With over 40 years of experience, I’m dedicated to providing information for all topics that involve neck and back pain.
January 26, 2024
Contact a Spine Specialist Near You!
Related Articles
Lower Back Pain | An Overview
Lower back pain is an exceedingly common affliction that affects up to 80% of adults at some point in their lives. Understanding the underlying causes of lower back pain is key to finding the appropriate treatment and relief. Anatomy of the Lower Back The lower back,...
Degenerative Disc Disease | Causes and Risk Factors
Degenerative disc disease describes age-related wear and tear to the rubbery spinal discs cushioning the vertebrae that can lead to chronic back or neck pain. While partly genetic, there are also lifestyle factors and injuries that accelerate disc degeneration over...
Upper (Thoracic) Back Pain | What is Causing My Pain?
Upper back pain is a surprisingly common affliction, affecting up to one-quarter of the adult population at some point. While not as prevalent as lower back pain, discomfort in the thoracic region still accounts for a substantial slice of musculoskeletal complaints...