FOREARM AND BICEPS CIRCUMFERENTIAL VARIATIONS IN SKIN TISSUE DIELECTRIC CONSTANT AND FIRMNESS

Abstract

Tissue dielectric constant (TDC) and
skin firmness assessed via indentation force
(FORCE) help quantify lymphedema and track
changes. We sought to determine potential
differences in these parameters dependent on
arm circumferential locations. Thus, TDC and
FORCE were measured in 40 healthy women
at medial, anterior and lateral locations on
forearm and biceps. In five other women with
unilateral lymphedema (68.6±7.6 years), TDC
was measured at corresponding circumferential
forearm positions. Measurements were done in
triplicate using compact noninvasive devices.
Results for healthy women (23.8±2.7 years)
showed forearm medial TDC values (26.7±2.2)
were less than anterior (28.0±2.4) or lateral
(28.0±2.5) positions (p<0.001). Lymphedema
patients had elevated values but similar medialanterior-
lateral patterns (33.7±8.0, 39.8±10.2
and 42.9±10.0). Biceps medial TDC values
(24.1±2.2) were also less than either anterior
(27.0±2.1) or lateral (28.2±3.3). Contrastingly,
medial FORCE values at forearm and biceps
were less than at anterior and lateral locations
(p<0.001) and increased in the order of medialanterior-
lateral on forearm (p<0.001). The
present findings provide reference values for
both TDC and FORCE of commonly measured
arm sites with specificity as to circumferential
variations. This observed variation indicates
the need for care in locating measurement
positions for tracking patients with
lymphedema.