The hypothenar eminence lies just
proximal to the little finger and extends longitudinally to the pisiform. This
eminence is composed of three mobile muscle: the abductor digiti quinti,
opponens digiti, and the flexor digiti quinti. These three muscles are indistinguishable
from each other since they lie in layers.
In appearance, the eminences bulge
slightly, lending an indented, cuplike shape to the center of the palm. This
shape is actually created by three arches. The arch framework is supported by
the hand’s intrinsic muscles, which, when absent or atrophic, cause the palm to
lose its normal contour and to appear flat, without concavity.
The hypothenar eminence and interossei muscles should be
checked for hypertrophy or atrophy. Since the eminence and interossei muscles is supplied by the ulnar
nerve, atrophy may result from ulnar nerve compression taking place either in
the tunnel of Guyon or, more proximally, in the extremity or ulnar nerve
paralysis.
DESCRIPTION
With the patient's hand supinated,
observe the contours of the hand. The patient can also abduct the little finger
against resistance by the examiner for hypothenars. Patient can also abduct their index finger against resistance by the examiner for first dorsal interosseous.
