Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Functions of the low back, or lumbar area, include
structural support, movement, and protection of certain body tissues.
Pain in the low back can be a result of conditions affecting the bony lumbar spine, discs between the vertebrae, ligaments around the spine and discs, spinal cord and nerves, muscles of the low back, internal organs of the pelvis and abdomen, and the skin covering the lumbar area.
Treatment of low back pain is optimally directed toward a diagnosed or suspected
specific cause. For acute lumbar strain, use of a home remedy initially can be beneficial.
What is the anatomy of the low back?
The first step to understanding low back pain is appreciating the normal design
(anatomy) of the tissues of this area of the body. Important structures of the
low back that can be related to symptoms in this region include the bony lumbar
spine (vertebrae, singular = vertebra), discs between the vertebrae, ligaments
around the spine and discs, spinal cord and nerves, muscles of the low back,
internal organs of the pelvis and abdomen, and the skin covering the lumbar
The bony lumbar spine is designed so that vertebrae "stacked" together can
provide a movable support structure while also protecting the spinal cord from
injury. The spinal cord is composed of nervous tissue that extends down the
spinal column from the brain. Each vertebra has a spinous process, a bony
prominence behind the spinal cord, which shields the cord's nervous tissue from
impact trauma. Vertebrae also have a strong bony "body" (vertebral body) in
front of the spinal cord to provide a platform suitable for weight bearing of
all tissues above the buttocks. The lumbar vertebrae stack immediately atop the
sacrum bone that is situated in between the buttocks. On each side, the sacrum
meets the iliac bone of the pelvis to form the sacroiliac joints of the
The discs are pads that serve as "cushions" between the individual vertebral
bodies. They help to minimize the impact of stress forces on the spinal column.
Each disc is designed like a jelly donut with a central, softer component
(nucleus pulposus) and a surrounding, firm outer ring (annulus fibrosus). The
central portion of the disc is capable of rupturing (herniating as in a
herniated disc) through the outer ring, causing irritation of adjacent nervous
tissue and sciatica as described below. Ligaments are strong fibrous soft tissues that firmly attach bones to bones. Ligaments attach each of the vertebrae to each other and surround each of the discs.
The nerves that provide sensation and stimulate the muscles of the low back as well as the lower extremities (the thighs, legs, feet, and toes)
all exit the lumbar spinal column through bony portals, each of which is called a "foramen."
Many muscle groups that are responsible for flexing, extending, and rotating the waist, as well as moving the lower extremities, attach to the lumbar spine through tendon insertions.
The aorta and blood vessels that transport blood to and from the lower extremities pass in front of the lumbar spine in the abdomen and pelvis. Surrounding these blood vessels are lymph nodes (lymph glands) and tissues of the involuntary nervous system that are important in maintaining bladder and bowel control.
The uterus and ovaries are important pelvic structures in front of the pelvic
area of women. The prostate gland is a significant pelvic structure in men. The
kidneys are on either side of the back of the lower abdomen, in front of the
The skin over the lumbar area is supplied by nerves that come from nerve roots
that exit from the lumbar spine.
What is the function of the low back?
The low back, or lumbar area, serves a number of important functions for the
human body. These functions include structural support, movement, and protection
of certain body tissues.
When we stand, the lower back is functioning to support the weight of
the upper body. When we bend, extend, or rotate at the waist, the lower back is
involved in the movement. Therefore, injury to the
for weight bearing, such as the bony spine, muscles, tendons, and ligaments,
often can be detected when the body is standing erect or used in various
Protecting the soft tissues of the nervous system and spinal cord as well as nearby organs of the pelvis and abdomen is a critical function the lumbar spine and adjacent muscles of the low back.
Epidural steroid injections are most commonly used in situations of radicular pain, which is a radiating pain that is transmitted away from the spine by an irritated spinal nerve. Irritation of a spinal nerve in the low back (lumbar radiculopathy) causes pain that goes down the leg. Epidural injections are also used to treat nerve compression in the neck (cervical spine), referred to as cervical radiculopathy, which causes pain.