The Back Injury Claim
WHAT DOES 80% of the population have dur- lion Americans suffer from low back pain each year,
ing their lifetime and is the second leading cause and 50% of those who experience an episode of
of missed time from work? Back pain is a major low back pain will have a repeat occurrence within
health problem that extracts an enormous emo- one year.
tional and financial toll. Musculoskeletal problems These statistics are staggering and demonstrate
cost the economy more than $215 billion annually, the great care that must be exercised in handling
and each year, 14% of the population suffers a back a back injury claim to ascertain the real cause of
impairment that will limit activities of daily living. the problem. This chapter examines the anatomy
(47 Am. Acad. Orthopaedic Surgeons Bull. (Oct. 1999).) of the spine and includes a discussion of the bones
Back symptoms are the second leading reason for that make up this structure, the cushions that allow
visits to physicians, and the most frequent cause for the spine to bend, and the soft tissues that hold the
orthopaedic and neurosurgical consultations. (Tay- vertebral column together. Information about spi-
lor, Deyo, Cherkin, and Kreuter, “Low Back Pain nal injuries and surgical repair techniques is also
Hospitalization—Recent United States Trends and presented, as well as litigation tips in order to assist
Regional Variations,” 19 Spine 1207 (1994).) It is the practitioner in presenting or defending a back
also the most common reason for disability in indi- injury claim.
viduals under the age of 45. (Linda S. Cunningham
and Jennifer L. Kelsey, “Epidemiology of Musculo- ANATOMY OF THE SPINE • The spine extends
skeletal Impairments and Associated Disability,” 74 from the base of the skull to near the bottom of the
Am. J. Pub. Health 574 (1984).) In excess of 65 mil- pelvis and consists of a number of bones, the verte-
96 | Anatomy For Litigators
brae, each of which is separated by soft cushion-like
pads, known as discs (see Fig. 7-1). Vertebrae are not
uniform in size and generally become larger in a
descending order because of their weight-bearing
responsibilities (see Fig. 7-2).
C1 is the atlas and is named after the Greek
character that carried the weight of the world on his
shoulders (see Fig. 7-4). In the human body, the atlas
Figure 7-1 carries the weight of the head. In turn, the atlas is
attached to the second vertebrae, which is called the
axis. The axis is different in shape from the other
spinal structures in that it has a bony projection that
arises straight up from the posterior part of the ver-
tebra. This stub is called the dens and allows the
head to rotate.
Major Regions Of The Spine
There are five regions of the spine consisting
of 26 bones. At birth, however, these bones number
33, but some fuse together with time. The cervical Figure 7-4
vertebrae consist of seven small and tightly grouped
Up-and-down motion occurs in the lower por-
bones, which support the head and provide a great
tion of the cervical spine, which flexibility makes the
deal of flexibility (see Fig. 7-3).
discs between the C5-6 and C6-7 levels vulnerable
The first bone starts at the base of the skull, to injury (see Fig. 7-5).
and the last one terminates at the first prominent Although the cervical region is mobile, it is
nodule, which can be palpated on the back of the very much at risk from a strong, sudden jerk such
neck. The neck is able to engage in two types of as that which occurs with a whiplash type of move-
movements: rotation and flexion/extension. Side- ment. This risk occurs because the neck has a lim-
to-side movement is the function of the first two ited muscle support system. Nevertheless, it must
vertebrae, or the C1 and C2 bones. still support the weight of the head, which is about
Back Injury | 97
6.2% of a person’s body weight or 10 pounds in a port the majority of the body’s weight (see Fig. 7-7).
person who weighs 160 pounds. (“Anatomy of the The first lumbar bone is located directly under the
Spine,” All About Back and Neck Pain, www.allabout- last thoracic vertebra, and the end of the lumbar
backandneckpain.com/html/spinesub.asp?id=45.) spine is located at the waist. This area of the back
Therefore, these muscles can be abused in a car ac- has great flexibility and is the subject of the highest
cident. number of back injuries.
Figure 7-5 Figure 7-7
The thoracic spine is the largest area of the The next level is the sacrum, a single fused unit
back and is made up of the next 12 vertebrae (see consisting of five bones that resemble an upside-
Fig. 7-6). These bones attach to the ribs and form down triangle (see Fig. 7-8). The sacrum sits inside
a fairly rigid unit. Therefore, very little movement the pelvis and forms part of that unit. The coccyx,
occurs in this region, and it is not a common loca- or tailbone, is the termination point of the spine and
tion for nerve root compression or herniated discs. is made up of several small pieces of bone. Coccy-
The first thoracic vertebra starts at a location paral- dynia is the term used to identify pain in this area.
lel to the collarbone, and the 12th bone ends at the
last rib, which is known as a floating rib. Because of
their anatomical positioning, the thoracic vertebrae
and rib cage protect many of the vital organs, such
as the lungs, liver, spleen, and heart.
PARTS OF THE SPINE
Spinal Part Number of Abbreviation
Cervical Seven bones C1 to C7
Figure 7-6 Thoracic Twelve bones T1 to T12
Lumbar Five bones L1 to L5
The lumbar region has the five largest verte- Sacrum Five fused bones S1 to S5
brae because their increased size is needed to sup- Coccyx Four fused bones None
98 | Anatomy For Litigators
Ligaments That Hold The Spine Together Curves Of The Spine
The spine has two sets of ligaments that hold When the spine is viewed anteriorly, it seems
the bones together. The first is the longitudinal liga- perfectly straight. A lateral examination, however,
ment, so-named because it runs the length of the reveals that the column has several gentle curves
vertebral column and holds the bones in place. The (see Fig. 7-11). These bends are present to allow the
ligament in the front is the anterior longitudinal vertebral column to act as a spring or shock absorb-
ligament, and the one in the back is the posterior er for the impacts of daily life. Some of the curves
longitudinal ligament (see Fig. 7-9). are normal, whereas others are not.
Figure 7-9 Figure 7-11
The construction of the posterior longitudinal The cervical and lumbar spines both have a
ligament makes the discs in the lower part of the lordotic curve, which represents a gentle bending
lumbar spine susceptible to herniation because the of this portion of the spine in an inward direction.
ligament narrows in this region and only covers a When the cervical curve is exaggerated, the person
small portion of the disc (see Fig. 7-10). Therefore, is said to have a swayback. The thoracic spine and
there is very little covering holding the discs in place sacrum complete the spring by having bends in the
at the L4-5 and L5-S1 levels. opposite direction. These curves are called kypho-
sis and represent gentle outward bends. When this
curve is exaggerated, the person is said to have a
humpback (see Fig. 7-12).
The ligamentum flavum is the second ligament
of the back that holds the vertebrae in place. This
term means “yellow ligament,” and it attaches to
the anterior portion of each lamina to help secure A bend of the spine to the lateral side repre-
the bones of the back. sents a condition called scoliosis. This problem gives