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Anatomy and Evaluation of the Lumbosacral Plexus
ELECTROMYOGRAPHY
1047-9651/98 $8.00
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ANATOMY AND EVALUATION OF THE LUMBOSACRAL PLEXUS Alice V. Fann, MD
The complex mobility and neuromuscular function of the lower extremities are served through innervation by the lumbosacral plexus. In its nervous constituency, this plexus is analogous to the brachial plexus in the following ways: (1) only the ventral primary rami of the nerve roots contribute to the plexus; (2) it is divided anatomically and functionally into two divisions, with the anterior division contributing to flexion and adduction and the posterior division subserving extension and abduction of the joints; (3) the nerve roots of both divisions contain motor and sensory fibers; and (4) the nerve roots can send branches to limb muscles before the roots join the plexus. The lumbosacral plexus is less prone to injury than the brachial plexus because it is afforded greater protection by the pelvic bones and the stability of the hip joint. This article describes the lumbosacral plexus and its anatomical relationships in order to promote an understanding of how the more prevalent injuries and diseases contribute to lumbosacral plexopathies. Approaches to the diagnosis and treatment of some of the plexopathies also are addressed. ANATOMY
The lumbosacral plexus can be divided into lumbar and sacral plexuses. In this article, they are considered separately when discussing the anatomical issues but are considered as a whole when discussing symptoms, causes, and diagnosis. The structure and anatomic relationships of the plexus and its branches are discussed correlatively in an attempt to understand how trauma, adventitious masses, systemic diseases, and therapeutic procedures affect them and contribute to plexopathies.
From the Department of Physical Medicine and Rehabilitation, John L. McClellan Veterans Affairs Hospital; and the Department of Physical Medicine and Rehabilitation, University of Arkansas for Medical Sciences, Little Rock, Arkansas
PHYSICAL MEDICINE AND REHABILITATION CLINICS OF NORTH AMERICA VOLUME 9 • NUMBER 4 • NOVEMBER 1998
815
1047-9651/98 $8.00
+
.00
ANATOMY AND EVALUATION OF THE LUMBOSACRAL PLEXUS Alice V. Fann, MD
The complex mobility and neuromuscular function of the lower extremities are served through innervation by the lumbosacral plexus. In its nervous constituency, this plexus is analogous to the brachial plexus in the following ways: (1) only the ventral primary rami of the nerve roots contribute to the plexus; (2) it is divided anatomically and functionally into two divisions, with the anterior division contributing to flexion and adduction and the posterior division subserving extension and abduction of the joints; (3) the nerve roots of both divisions contain motor and sensory fibers; and (4) the nerve roots can send branches to limb muscles before the roots join the plexus. The lumbosacral plexus is less prone to injury than the brachial plexus because it is afforded greater protection by the pelvic bones and the stability of the hip joint. This article describes the lumbosacral plexus and its anatomical relationships in order to promote an understanding of how the more prevalent injuries and diseases contribute to lumbosacral plexopathies. Approaches to the diagnosis and treatment of some of the plexopathies also are addressed. ANATOMY
The lumbosacral plexus can be divided into lumbar and sacral plexuses. In this article, they are considered separately when discussing the anatomical issues but are considered as a whole when discussing symptoms, causes, and diagnosis. The structure and anatomic relationships of the plexus and its branches are discussed correlatively in an attempt to understand how trauma, adventitious masses, systemic diseases, and therapeutic procedures affect them and contribute to plexopathies.
From the Department of Physical Medicine and Rehabilitation, John L. McClellan Veterans Affairs Hospital; and the Department of Physical Medicine and Rehabilitation, University of Arkansas for Medical Sciences, Little Rock, Arkansas
PHYSICAL MEDICINE AND REHABILITATION CLINICS OF NORTH AMERICA VOLUME 9 • NUMBER 4 • NOVEMBER 1998
815