Introduction to Low Back Pain

Introduction to Low Back Pain, Acute vs Chronic

Introduction to Low Back Pain, Nociceptive vs Neuropathic

Introduction to Low Back Pain, Local vs Referred

Low back pain:

• Affects 4 out of 5 Americans at some point in their lives
• Most common disability for those between 19 and 45
• 2nd most common cause of work absence
• Treatment cost > $80 billion per year
• Disability claims > $8 billion per year

Low back pain:

• Not a single disease
• Set of symptoms may be due to any of a number of conditions
• In many sufferers, a discrete cause is never identified

One of the most important pain classification divisions is the duration of pain.

Acute low back pain:

• Short-term, usually lasting no more than one month
• Result of an injury or illness
• Disappears after treated and damaged tissue has healed

Chronic low back pain:

• Pain lasting longer than 3 months
• May be due to long-term incurable or intractable medical condition
• May last for years

One important classification of pain distinguishes nociceptive from neuropathic pain.

Nociceptive pain:

• Part of the normal function of the nervous system

Neuropathic pain:

• Results from injury to or impairment of nerves

Common type of neuropathic low back pain:

• Sciatica

Sciatica:

• Caused by injury to the sciatic nerve, or one of its branches
• Pain may be experienced anywhere along the nerve
• Nerve may be injured by a fall, by a mechanical problem in the spine such as a herniated disc, or by a tumor

The location of injury may be the same as or different from the location where pain is felt.

Local pain:

• Originates at site where felt

Low back pain is local pain if its source is in: 

• Bone
• Muscle
• Connective tissue of the lower back

Referred pain:

• Originates at site remote from where felt
• Happens because some groups of sensory neurons from different anatomical sites share the same segments of the spinal cord to the brain
• Pain caused by disease in the kidneys, bladder, prostate gland, or uterus

Pain: Current Understanding of Assessment, Management, and Treatments.  National Pharmaceutical Council, Inc.  Dec 2001.

The Merck Manual of Medical Information, 2nd Home Edition. 

Human Anatomy & Physiology, 6th ed.  EN Marieb, 2004.

Ehrlich GE: Low Back Pain.  Bulletin of the World Health Organization 2003, 81 (9).